WO2024203149A1 - Noise suppression device - Google Patents

Abstract

The present disclosure relates to a noise suppression device that makes it possible to appropriately reduce noise at low cost. In the noise suppression device, a base part in which an acceleration sensor is formed and a drive unit in which a voice coil is formed are connected with each other in an attachable/detachable state. This device is applicable to NC devices.

Description

Noise suppression devices

This disclosure relates to a noise suppression device, and in particular to a noise suppression device that can appropriately reduce noise.

Conventionally, a technique has been proposed for reducing noise inside a vehicle, in which a microphone (error microphone) that detects noise is placed near the user's ear, which serves as the control point, and an anti-phase sound is generated to cancel the picked-up noise (see Patent Document 1).

However, in the invention of Patent Document 1, a microphone that picks up noise is installed at a fixed position near the user's ear, which serves as the control point, but there is a risk that noise may not be reduced appropriately if the seat position or the direction of the user's head changes.

In response, technology has been proposed that adaptively reduces noise depending on the seat position and the direction of the user's head (see Patent Document 2).

Japanese Patent Application Publication No. 6-332469 JP 2022-59096 A

However, since it does not follow changes in the condition of the tires or road surface, which are the source of noise, there is a risk that noise will not be reduced appropriately.

This disclosure has been made in light of these circumstances, and is intended in particular to enable appropriate noise reduction.

A noise suppression device according to one aspect of the present disclosure includes an acceleration sensor that detects the acceleration of an object that generates sound through vibration, a vibration device that vibrates the object, a filter processing unit that applies noise cancellation filter processing to a sensor signal that is the detection result of the acceleration sensor to generate a drive signal that vibrates the vibration device so as to suppress vibration of the object, a drive unit in which the vibration device is stored, and a base unit that fixes the drive unit to the object, and the acceleration sensor is disposed on the base unit, and the base unit and the drive unit are connected in a detachable manner to form a noise suppression device.

In one aspect of the present disclosure, the device includes an acceleration sensor that detects the acceleration of an object that generates sound through vibration, a vibration device that vibrates the object, a filter processing unit that applies noise cancellation filter processing to a sensor signal that is the detection result of the acceleration sensor to generate a drive signal that vibrates the vibration device so as to suppress vibration of the object, a drive unit in which the vibration device is stored, and a base unit that fixes the drive unit to the object, and the acceleration sensor is disposed on the base unit, and the base unit and the drive unit are connected in a detachable state.

FIG. 1 is a block diagram showing an example of the configuration of a vehicle control system. FIG. 2 is a diagram showing an example of a sensing region. 1 is a diagram illustrating an FF type NC device according to a first embodiment of the present disclosure; FIG. 2 is a functional block diagram illustrating functions realized by an FF type NC device. 5 is a functional block diagram illustrating a configuration example of a filter generation processing unit that generates a sensor filter set and a cancellation filter set used by the NC device of FIG. 4. FIG. 6 is a functional block diagram for explaining functions realized by the filter design unit of FIGS. 4 and 5. 6 is a flowchart illustrating a filter generation process by the filter generation processing unit in FIG. 5 . 5 is a flowchart illustrating an NC process performed by the NC device of FIG. 4. 1 is a diagram illustrating an FF-type NC device that is a first modified example of the first embodiment of the present disclosure. FIG. 10 is a functional block diagram illustrating a configuration example of a filter generation processing unit that generates a sensor filter set and a cancellation filter set used by the NC device of FIG. 9. 13 is a diagram illustrating an FF-type NC device that is a second modified example of the first embodiment of the present disclosure. FIG. 12 is a functional block diagram illustrating a configuration example of a filter generation processing unit that generates a sensor filter set and a cancellation filter set used by the NC device of FIG. 11. 13 is a flowchart illustrating a filter generation process by the filter generation processing unit in FIG. 12 . 12 is a flowchart illustrating an NC process performed by the NC device of FIG. 11 . FIG. 13 is a diagram illustrating an FF-type NC device that is a third modified example of the first embodiment of the present disclosure. 16 is a functional block diagram illustrating a configuration example of a filter generation processing unit that generates a sensor filter set and a cancellation filter set used by the NC device of FIG. 15. 17 is a flowchart illustrating a filter generation process by the filter generation processing unit in FIG. 16 . 16 is a flowchart illustrating NC processing by the NC device of FIG. 15 . FIG. 13 is a diagram illustrating an FF-type NC device which is a fourth modified example of the first embodiment of the present disclosure. 20 is a functional block diagram illustrating an example of the configuration of a filter generation processing unit that generates a sensor filter set and a cancellation filter set used by the NC device of FIG. 19. FIG. 13 is a diagram illustrating an FB type NC device according to a second embodiment of the present disclosure. FIG. 23 is a diagram illustrating the external configuration of the NC device of FIG. 22. 22 is a diagram for explaining a configuration example of an actuator in the NC apparatus of FIG. 21. FIG. 22 is a diagram for explaining a configuration example of an NC processing unit in the NC apparatus of FIG. 21. 22 is a flowchart illustrating NC processing by the NC device of FIG. 21. 13A to 13C are diagrams illustrating a configuration example of an actuator according to a first modified example of the second embodiment of the present disclosure. 13A to 13C are diagrams illustrating a configuration example of an actuator according to a second modified example of the second embodiment of the present disclosure. 28 is a diagram for explaining a method of installing the actuator of FIG. 27. FIG. 28A to 28C are diagrams illustrating a method for replacing the drive unit of the actuator of FIG. 27. 13A to 13C are diagrams illustrating a configuration example of an actuator according to a third modified example of the second embodiment of the present disclosure. 13A to 13C are diagrams illustrating a configuration example of an actuator according to a fourth modified example of the second embodiment of the present disclosure. 13A to 13C are diagrams illustrating a configuration example of an actuator according to a fifth modified example of the second embodiment of the present disclosure. 13A to 13C are diagrams illustrating a configuration example of an actuator according to a sixth modified example of the second embodiment of the present disclosure. FIG. 13 is a diagram illustrating a configuration example of an actuator according to a seventh modified example of the second embodiment of the present disclosure. 11A and 11B are diagrams illustrating compliance characteristics of a damper of an actuator according to temperature. FIG. 13 is a diagram illustrating a configuration example of an NC processing unit which is an eighth modified example of the second embodiment of the present disclosure. 37 is a flowchart illustrating an operation mode control process by the NC processing unit of FIG. 36. FIG. 13 is a diagram illustrating a configuration example of an NC processing unit which is a ninth modified example of the second embodiment of the present disclosure. 39 is a flowchart illustrating an operation mode control process by the NC processing unit of FIG. 38. FIG. 13 is a diagram illustrating a configuration example of an NC processing unit which is a ninth modified example of the second embodiment of the present disclosure. FIG. 1 is a diagram illustrating an example of detection of unevenness on a road surface using LiDAR. FIG. 1 is a diagram illustrating an NC device that combines an FB type NC device and an FF type NC device. 10A and 10B are diagrams illustrating the difference in transmission of sudden sounds between a sensor of an FB type NC device and a sensor of an FF type NC device. FIG. 13 is a diagram illustrating an NC device that combines an FB type NC device and an FF type NC device according to a third embodiment of the present disclosure. FIG. 45 is a functional block diagram illustrating functions realized by the NC device of FIG. 44. 11A and 11B are diagrams illustrating a countermeasure process for a sudden sound. 46 is a flowchart illustrating a sudden sound prevention process performed by the NC device of FIG. 45. FIG. 13 is a diagram illustrating a configuration example of an NC device which is a first modified example of the third embodiment of the present disclosure. 11A and 11B are diagrams illustrating an example of a filter gain of an NC filter that cancels a vibration level when a sudden sound occurs. 49 is a flowchart illustrating a sudden sound prevention process performed by the NC device of FIG. 48. FIG. 13 is a diagram illustrating a configuration example of an NC device which is a second modified example of the third embodiment of the present disclosure. 52 is a flowchart illustrating a sudden sound prevention process performed by the NC device of FIG. 51. FIG. 13 is a diagram illustrating a configuration example of an NC device which is a third modified example of the third embodiment of the present disclosure. FIG. 13 is a diagram illustrating an NC device which is a fourth modified example of the third embodiment of the present disclosure. FIG. 55 is a functional block diagram illustrating functions realized by the NC device of FIG. 54. 56 is a flowchart illustrating NC processing by the NC device of FIG. 55. FIG. 13 is a diagram illustrating an NC device which is a fifth modified example of the third embodiment of the present disclosure. FIG. 58 is a functional block diagram illustrating functions realized by the NC device of FIG. 57. 59 is a flowchart illustrating NC processing by the NC device of FIG. 58. FIG. 13 is a diagram illustrating an NC device which is a sixth modified example of the third embodiment of the present disclosure. FIG. 61 is a functional block diagram illustrating functions realized by the NC device of FIG. 60. FIG. 13 is a diagram illustrating an NC device which is a seventh modified example of the third embodiment of the present disclosure. FIG. 13 is a diagram illustrating a GUI for setting an NC device that is an eighth modified example of the third embodiment of the present disclosure. 2 shows an example of the configuration of a general-purpose computer.

Below, a preferred embodiment of the present disclosure will be described in detail with reference to the attached drawings. Note that in this specification and drawings, components having substantially the same functional configurations are designated by the same reference numerals to avoid redundant description.

Hereinafter, an embodiment of the present technology will be described in the following order.
1. Configuration Example of Vehicle Control System 2. First Embodiment 3. First Modification of the First Embodiment 4. Second Modification of the First Embodiment 5. Third Modification of the First Embodiment 6. Fourth Modification of the First Embodiment 7. Second Embodiment 8. First Modification of the Second Embodiment 9. Second Modification of the Second Embodiment 10. Third Modification of the Second Embodiment 11. Fourth Modification of the Second Embodiment 12. Fifth Modification of the Second Embodiment 13. Sixth Modification of the Second Embodiment 14. Seventh Modification of the Second Embodiment 15. Eighth Modification of the Second Embodiment 16. Ninth Modification of the Second Embodiment 17. Tenth Modification of the Second Embodiment 18. Third Embodiment 19. First Modification of the Third Embodiment 20. Second Modification of the Third Embodiment 21. Third Modification of the Third Embodiment 22. Fourth Modification of the Third Embodiment 23. Fifth Modification of the Third Embodiment 24. Sixth Modification of the Third Embodiment 25. Seventh Modification of the Third Embodiment 26. Eighth Modification of the Third Embodiment 27. Example of Execution by Software

<<1. Configuration example of vehicle control system>>
FIG. 1 is a block diagram showing an example of the configuration of a vehicle control system 11, which is an example of a mobility device control system to which the present technology is applied.

The vehicle control system 11 is provided in the vehicle 1 and performs processing related to the automated driving of the vehicle 1. This automated driving includes driving automation of levels 1 to 5, as well as remote driving and remote assistance of the vehicle 1 by a remote driver.

The vehicle control system 11 includes a vehicle control ECU (Electronic Control Unit) 21, a communication unit 22, a map information storage unit 23, a location information acquisition unit 24, an external recognition sensor 25, an in-vehicle sensor 26, a vehicle sensor 27, a memory unit 28, a driving automation control unit 29, a DMS (Driver Monitoring System) 30, an HMI (Human Machine Interface) 31, a vehicle control unit 32, and an NC (Noise Cancelling) device 33.

The vehicle control ECU 21, communication unit 22, map information storage unit 23, position information acquisition unit 24, external recognition sensor 25, in-vehicle sensor 26, vehicle sensor 27, memory unit 28, driving automation control unit 29, DMS 30, HMI 31, vehicle control unit 32, and NC device 33 are connected to each other so as to be able to communicate with each other via a communication network 41. The communication network 41 is composed of an in-vehicle communication network or bus that complies with digital two-way communication standards such as CAN (Controller Area Network), LIN (Local Interconnect Network), LAN (Local Area Network), FlexRay (registered trademark), and Ethernet (registered trademark). The communication network 41 may be used differently depending on the type of data being transmitted. For example, CAN may be applied to data related to vehicle control, and Ethernet may be applied to large-volume data. In addition, each part of the vehicle control system 11 may be directly connected without going through the communication network 41, using wireless communication intended for communication over relatively short distances, such as near field communication (NFC) or Bluetooth (registered trademark).

Note that, hereinafter, when each part of the vehicle control system 11 communicates via the communication network 41, the description of the communication network 41 will be omitted. For example, when the vehicle control ECU 21 and the communication unit 22 communicate via the communication network 41, it will simply be described as the vehicle control ECU 21 and the communication unit 22 communicating with each other.

The vehicle control ECU 21 is composed of various processors, such as a CPU (Central Processing Unit) and an MPU (Micro Processing Unit). The vehicle control ECU 21 controls all or part of the functions of the vehicle control system 11.

The communication unit 22 communicates with various devices inside and outside the vehicle, other vehicles, servers, base stations, etc., and transmits and receives various types of data. At this time, the communication unit 22 can communicate using multiple communication methods.

The following provides an overview of the communications with the outside of the vehicle that can be performed by the communication unit 22. The communication unit 22 communicates with servers (hereinafter referred to as external servers) on an external network via base stations or access points using wireless communication methods such as 5G (fifth generation mobile communication system), LTE (Long Term Evolution), and DSRC (Dedicated Short Range Communications). The external network with which the communication unit 22 communicates is, for example, the Internet, a cloud network, or an operator-specific network. The communication method that the communication unit 22 uses with the external network is not particularly limited as long as it is a wireless communication method that allows digital two-way communication at a communication speed equal to or higher than a predetermined distance.

Furthermore, for example, the communication unit 22 can communicate with a terminal present in the vicinity of the vehicle using P2P (Peer To Peer) technology. The terminal present in the vicinity of the vehicle can be, for example, a terminal attached to a mobile object moving at a relatively slow speed, such as a pedestrian or a bicycle, a terminal installed at a fixed position in a store, or an MTC (Machine Type Communication) terminal. Furthermore, the communication unit 22 can also perform V2X communication. V2X communication refers to communication between the vehicle and others, such as vehicle-to-vehicle communication with other vehicles, vehicle-to-infrastructure communication with roadside devices, vehicle-to-home communication with a home, and vehicle-to-pedestrian communication with a terminal carried by a pedestrian, etc.

The communication unit 22 can, for example, receive from the outside a program for updating software that controls the operation of the vehicle control system 11 (Over the Air). The communication unit 22 can further receive map information, traffic information, information about the surroundings of the vehicle 1, etc. from the outside. Also, for example, the communication unit 22 can transmit information about the vehicle 1 and information about the surroundings of the vehicle 1 to the outside. Information about the vehicle 1 that the communication unit 22 transmits to the outside includes, for example, data indicating the state of the vehicle 1, recognition results by the recognition unit 73, etc. Furthermore, for example, the communication unit 22 performs communication corresponding to a vehicle emergency notification system such as e-Call.

For example, the communication unit 22 receives electromagnetic waves transmitted by a road traffic information and communication system (VICS (Vehicle Information and Communication System) (registered trademark)) such as a radio beacon, optical beacon, or FM multiplex broadcasting.

The following provides an overview of the communication that the communication unit 22 can perform with the inside of the vehicle. The communication unit 22 can communicate with each device in the vehicle using, for example, wireless communication. The communication unit 22 can perform wireless communication with each device in the vehicle using a communication method that allows digital two-way communication at a communication speed equal to or higher than a predetermined speed via wireless communication, such as wireless LAN, Bluetooth, NFC, or WUSB (Wireless USB). Not limited to this, the communication unit 22 can also communicate with each device in the vehicle using wired communication. For example, the communication unit 22 can communicate with each device in the vehicle using wired communication via a cable connected to a connection terminal (not shown). The communication unit 22 can communicate with each device in the vehicle using a communication method that allows digital two-way communication at a communication speed equal to or higher than a predetermined speed via wired communication, such as USB (Universal Serial Bus), HDMI (High-Definition Multimedia Interface) (registered trademark), or MHL (Mobile High-definition Link).

Here, the in-vehicle device refers to, for example, a device that is not connected to the communication network 41 inside the vehicle. Examples of in-vehicle devices include mobile devices and wearable devices carried by users inside the vehicle, such as the driver, and information devices brought into the vehicle and temporarily installed.

The map information storage unit 23 stores one or both of a map acquired from an external source and a map created by the vehicle 1. For example, the map information storage unit 23 stores a three-dimensional high-precision map, a global map that is less accurate than a high-precision map and covers a wide area, etc.

High-precision maps include, for example, dynamic maps, point cloud maps, and vector maps. A dynamic map is, for example, a map consisting of four layers of dynamic information, semi-dynamic information, semi-static information, and static information, and is provided to the vehicle 1 from an external server or the like. A point cloud map is a map made up of a point cloud (point group data). A vector map is, for example, a map that is adapted for driving automation by associating traffic information such as the positions of lanes and traffic lights with a point cloud map.

The point cloud map and vector map may be provided, for example, from an external server, or may be created in the vehicle 1 based on sensing results from the camera 51, radar 52, LiDAR 53, etc. as a map for matching with a local map described below, and stored in the map information storage unit 23. In addition, when a high-precision map is provided from an external server, etc., map data of, for example, an area of several hundred meters square regarding the planned route along which the vehicle 1 will travel is acquired from the external server, etc., in order to reduce communication capacity.

The location information acquisition unit 24 receives GNSS signals from Global Navigation Satellite System (GNSS) satellites and acquires location information of the vehicle 1. The acquired location information is supplied to the driving automation control unit 29. Note that the location information acquisition unit 24 is not limited to a method using GNSS signals, and may acquire location information using a beacon, for example.

The external recognition sensor 25 includes various sensors used to recognize the situation outside the vehicle 1, and supplies sensor data from each sensor to each part of the vehicle control system 11. The type and number of sensors included in the external recognition sensor 25 are arbitrary.

For example, the external recognition sensor 25 includes a camera 51, a radar 52, a LiDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging) 53, and an ultrasonic sensor 54. Without being limited to this, the external recognition sensor 25 may be configured to include one or more types of sensors among the camera 51, the radar 52, the LiDAR 53, and the ultrasonic sensor 54. The number of cameras 51, radars 52, LiDAR 53, and ultrasonic sensors 54 is not particularly limited as long as it is a number that can be realistically installed on the vehicle 1. Furthermore, the types of sensors included in the external recognition sensor 25 are not limited to this example, and the external recognition sensor 25 may include other types of sensors. Examples of the sensing areas of each sensor included in the external recognition sensor 25 will be described later.

The imaging method of camera 51 is not particularly limited. For example, cameras of various imaging methods, such as a ToF (Time Of Flight) camera, a stereo camera, a monocular camera, and an infrared camera, which are imaging methods capable of distance measurement, can be applied to camera 51 as necessary. However, the present invention is not limited to this, and camera 51 may be a camera simply for acquiring photographic images, without being related to distance measurement.

Furthermore, for example, the external recognition sensor 25 can be equipped with an environmental sensor for detecting the environment relative to the vehicle 1. The environmental sensor is a sensor for detecting the environment such as the weather, climate, brightness, etc., and can include various sensors such as a raindrop sensor, fog sensor, sunlight sensor, snow sensor, illuminance sensor, etc.

Furthermore, for example, the external recognition sensor 25 includes a microphone that is used to detect sounds around the vehicle 1 and the location of sound sources.

The in-vehicle sensor 26 includes various sensors for detecting information inside the vehicle, and supplies sensor data from each sensor to each part of the vehicle control system 11. There are no particular limitations on the types and number of the various sensors included in the in-vehicle sensor 26, so long as they are of the types and number that can be realistically installed in the vehicle 1.

For example, the in-vehicle sensor 26 may be equipped with one or more types of sensors including a camera, radar, a seating sensor, a steering wheel sensor, a microphone, and a biometric sensor. The camera equipped in the in-vehicle sensor 26 may be a camera using various imaging methods capable of measuring distances, such as a ToF camera, a stereo camera, a monocular camera, or an infrared camera. Not limited to this, the camera equipped in the in-vehicle sensor 26 may be a camera simply for acquiring captured images, regardless of distance measurement. The biometric sensor equipped in the in-vehicle sensor 26 is provided, for example, on a seat, steering wheel, etc., and detects various types of biometric information of the user.

The vehicle sensor 27 includes various sensors for detecting the state of the vehicle 1, and supplies sensor data from each sensor to each part of the vehicle control system 11. There are no particular limitations on the types and number of the various sensors included in the vehicle sensor 27, so long as they are of the types and number that can be realistically installed on the vehicle 1.

For example, the vehicle sensor 27 includes a speed sensor, an acceleration sensor, an angular velocity sensor (gyro sensor), and an inertial measurement unit (IMU) that integrates these. For example, the vehicle sensor 27 includes a steering angle sensor that detects the steering angle of the steering wheel, a yaw rate sensor, an accelerator sensor that detects the amount of accelerator pedal operation, and a brake sensor that detects the amount of brake pedal operation. For example, the vehicle sensor 27 includes a rotation sensor that detects the number of rotations of the engine or motor, an air pressure sensor that detects the air pressure of the tires, a slip ratio sensor that detects the slip ratio of the tires, and a wheel speed sensor that detects the rotation speed of the wheels. For example, the vehicle sensor 27 includes a battery sensor that detects the remaining charge and temperature of the battery, and an impact sensor that detects external impacts.

The memory unit 28 includes at least one of a non-volatile storage medium and a volatile storage medium, and stores data and programs. The memory unit 28 is used, for example, as an EEPROM (Electrically Erasable Programmable Read Only Memory) and a RAM (Random Access Memory), and the storage medium may be a magnetic storage device such as a hard disc drive (HDD), a semiconductor storage device, an optical storage device, or a magneto-optical storage device. The memory unit 28 stores various programs and data used by each part of the vehicle control system 11. For example, the memory unit 28 includes an EDR (Event Data Recorder) and a DSSAD (Data Storage System for Automated Driving), and stores information about the vehicle 1 before and after an event such as an accident, and information acquired by the in-vehicle sensor 26.

The driving automation control unit 29 controls the driving automation function of the vehicle 1. For example, the driving automation control unit 29 includes an analysis unit 61, an action planning unit 62, and an operation control unit 63.

The analysis unit 61 performs analysis processing of the vehicle 1 and the surrounding conditions. The analysis unit 61 includes a self-position estimation unit 71, a sensor fusion unit 72, and a recognition unit 73.

The self-position estimation unit 71 estimates the self-position of the vehicle 1 based on the sensor data from the external recognition sensor 25 and the high-precision map stored in the map information storage unit 23. For example, the self-position estimation unit 71 generates a local map based on the sensor data from the external recognition sensor 25, and estimates the self-position of the vehicle 1 by matching the local map with the high-precision map. The position of the vehicle 1 is based on, for example, the center of the rear wheel pair axle.

The local map is, for example, a three-dimensional high-precision map or an occupancy grid map created using technology such as SLAM (Simultaneous Localization and Mapping). The three-dimensional high-precision map is, for example, the point cloud map described above. The occupancy grid map is a map in which the three-dimensional or two-dimensional space around the vehicle 1 is divided into grids of a predetermined size, and the occupancy state of objects is shown on a grid-by-grid basis. The occupancy state of objects is indicated, for example, by the presence or absence of an object and the probability of its existence. The local map is also used, for example, in the detection and recognition processing of the situation outside the vehicle 1 by the recognition unit 73.

The self-position estimation unit 71 may estimate the self-position of the vehicle 1 based on the position information acquired by the position information acquisition unit 24 and the sensor data from the vehicle sensor 27.

The sensor fusion unit 72 performs sensor fusion processing to obtain information by combining multiple different types of sensor data (e.g., image data supplied from the camera 51 and sensor data supplied from the radar 52). Methods for combining different types of sensor data include compounding, integration, fusion, and association.

The recognition unit 73 executes a detection process to detect the situation outside the vehicle 1, and a recognition process to recognize the situation outside the vehicle 1.

For example, the recognition unit 73 performs detection and recognition processing of the situation outside the vehicle 1 based on information from the external recognition sensor 25, information from the self-position estimation unit 71, information from the sensor fusion unit 72, etc.

Specifically, for example, the recognition unit 73 performs detection processing and recognition processing of objects around the vehicle 1. Object detection processing is, for example, processing to detect the presence or absence, size, shape, position, movement, etc. of an object. Object recognition processing is, for example, processing to recognize attributes such as the type of object, and to identify a specific object. However, detection processing and recognition processing are not necessarily clearly separated, and there may be overlap.

For example, the recognition unit 73 detects objects around the vehicle 1 by performing clustering to classify a point cloud based on sensor data from the radar 52, the LiDAR 53, or the like into clusters of points. This allows the presence or absence, size, shape, and position of objects around the vehicle 1 to be detected.

For example, the recognition unit 73 detects the movement of objects around the vehicle 1 by performing tracking to follow the movement of clusters of point clouds classified by clustering. This allows the speed and direction of travel (movement vector) of objects around the vehicle 1 to be detected.

For example, the recognition unit 73 detects or recognizes vehicles, people, bicycles, obstacles, structures, roads, traffic lights, traffic signs, road markings, etc. based on image data supplied from the camera 51. The recognition unit 73 may also recognize the types of objects around the vehicle 1 by performing recognition processing such as semantic segmentation.

For example, the recognition unit 73 can perform recognition processing of traffic rules around the vehicle 1 based on the map stored in the map information storage unit 23, the result of self-location estimation by the self-location estimation unit 71, and the result of recognition of objects around the vehicle 1 by the recognition unit 73. Through this processing, the recognition unit 73 can recognize the positions and states of traffic lights, the contents of traffic signs and road markings, the contents of traffic regulations, and lanes on which travel is possible, etc.

For example, the recognition unit 73 can perform recognition processing of the environment around the vehicle 1. The surrounding environment that the recognition unit 73 recognizes may include weather, temperature, humidity, brightness, and road surface conditions.

The behavior planning unit 62 creates a behavior plan for the vehicle 1. For example, the behavior planning unit 62 creates the behavior plan by performing route planning and route following processing.

Route planning includes global path planning and local path planning. Global path planning involves planning a rough route from the start to the goal. Local path planning, also known as trajectory planning, involves generating a trajectory that allows safe and smooth progress in the vicinity of vehicle 1 on the planned route, taking into account the motion characteristics of vehicle 1.

Path following is a process of planning operations for traveling safely and accurately along a route planned by a route plan within a planned time. The action planning unit 62 can, for example, calculate the target speed and target angular velocity of the vehicle 1 based on the results of this path following process.

The operation control unit 63 controls the operation of the vehicle 1 to realize the action plan created by the action planning unit 62.

For example, the operation control unit 63 controls the steering control unit 81, the brake control unit 82, and the drive control unit 83 included in the vehicle control unit 32 described below, to perform lateral vehicle motion control and longitudinal vehicle motion control so that the vehicle 1 proceeds along the trajectory calculated by the trajectory plan. For example, the operation control unit 63 performs control for the purpose of driving automation, such as driver assistance functions such as collision avoidance or impact mitigation, following driving, maintaining vehicle speed, collision warning for the vehicle itself, and lane departure warning for the vehicle itself, and driving without the operation of the driver or a remote driver.

The DMS 30 performs processes such as authenticating the driver and recognizing the driver's state based on the sensor data from the in-vehicle sensors 26 and the input data input to the HMI 31 (described later). Examples of the driver's state to be recognized include physical condition, alertness, concentration, fatigue, line of sight, level of intoxication, driving operation, posture, etc.

The DMS 30 may also perform authentication processing for users other than the driver and recognition processing for the status of the users. For example, the DMS 30 may also perform recognition processing for the status inside the vehicle based on sensor data from the in-vehicle sensor 26. Examples of the status inside the vehicle that may be recognized include temperature, humidity, brightness, odor, etc.

HMI31 inputs various data and instructions, and displays various data to the user.

The following provides an overview of data input using the HMI 31. The HMI 31 is equipped with an input device that allows a person to input data. The HMI 31 generates input signals based on data and instructions input via the input device, and supplies the signals to each part of the vehicle control system 11. The HMI 31 is equipped with input devices such as a touch panel, buttons, switches, and levers. Without being limited to these, the HMI 31 may further be equipped with an input device that allows information to be input by a method other than manual operation, such as voice or gestures. Furthermore, the HMI 31 may use, as an input device, an externally connected device such as a remote control device that uses infrared or radio waves, or a mobile device or wearable device that supports the operation of the vehicle control system 11.

The presentation of data by the HMI 31 will be briefly described below. The HMI 31 generates visual information, auditory information, and tactile information for the user or the outside of the vehicle. The HMI 31 also performs output control to control the output, output content, output timing, output method, etc. of each piece of generated information. The HMI 31 generates and outputs, as visual information, information indicated by images or light, such as an operation screen, vehicle 1 status display, warning display, and monitor image showing the situation around the vehicle 1. The HMI 31 also generates and outputs, as auditory information, information indicated by sounds, such as voice guidance, warning sounds, and warning messages. The HMI 31 also generates and outputs, as tactile information, information that is imparted to the user's sense of touch by force, vibration, movement, etc.

The output device from which the HMI 31 outputs visual information may be, for example, a display device that presents visual information by displaying an image itself, or a projector device that presents visual information by projecting an image. Note that the display device may be a device that displays visual information within the user's field of vision, such as a head-up display, a transmissive display, or a wearable device with an AR (Augmented Reality) function, in addition to a display device having a normal display. The HMI 31 may also use display devices such as a navigation device, instrument panel, CMS (Camera Monitoring System), electronic mirror, lamp, etc., provided in the vehicle 1 as output devices that output visual information.

The output device through which the HMI 31 outputs auditory information can be, for example, an audio speaker, headphones, or earphones.

Haptic elements using haptic technology can be used as an output device for the HMI 31 to output tactile information. Haptic elements are provided on parts that the user touches, such as the steering wheel and the seat.

The vehicle control unit 32 controls each part of the vehicle 1. The vehicle control unit 32 includes a steering control unit 81, a brake control unit 82, a drive control unit 83, a body control unit 84, a light control unit 85, and a horn control unit 86.

The steering control unit 81 detects and controls the state of the steering system of the vehicle 1. The steering system includes, for example, a steering mechanism including a steering wheel, an electric power steering, etc. The steering control unit 81 includes, for example, a steering ECU that controls the steering system, an actuator that drives the steering system, etc.

The brake control unit 82 detects and controls the state of the brake system of the vehicle 1. The brake system includes, for example, a brake mechanism including a brake pedal, an ABS (Antilock Brake System), a regenerative brake mechanism, etc. The brake control unit 82 includes, for example, a brake ECU that controls the brake system, and an actuator that drives the brake system.

The drive control unit 83 detects and controls the state of the drive system of the vehicle 1. The drive system includes, for example, an accelerator pedal, a drive force generating device for generating drive force such as an internal combustion engine or a drive motor, and a drive force transmission mechanism for transmitting the drive force to the wheels. The drive control unit 83 includes, for example, a drive ECU for controlling the drive system, and an actuator for driving the drive system.

The body system control unit 84 detects and controls the state of the body system of the vehicle 1. The body system includes, for example, a keyless entry system, a smart key system, a power window device, a power seat, an air conditioning system, an airbag, a seat belt, a shift lever, etc. The body system control unit 84 includes, for example, a body system ECU that controls the body system, an actuator that drives the body system, etc.

The light control unit 85 detects and controls the state of various lights of the vehicle 1. Examples of lights to be controlled include headlights, backlights, fog lights, turn signals, brake lights, projections, and bumper displays. The light control unit 85 includes a light ECU that controls the lights, an actuator that drives the lights, and the like.

The horn control unit 86 detects and controls the state of the car horn of the vehicle 1. The horn control unit 86 includes, for example, a horn ECU that controls the car horn, an actuator that drives the car horn, etc.

The NC (Noise Cancellation or Noise Control) device 33 suppresses noises that occur while driving, such as road noise and wind noise. The detailed configuration of the NC device 33 will be described later in Figure 3 and subsequent figures.

FIG. 2 is a diagram showing an example of a sensing area by the camera 51, radar 52, LiDAR 53, ultrasonic sensor 54, etc. of the external recognition sensor 25 in FIG. 1. Note that FIG. 2 shows a schematic view of the vehicle 1 as seen from above, with the left end side being the front end of the vehicle 1 and the right end side being the rear end of the vehicle 1.

Sensing area 101F and sensing area 101B show examples of sensing areas of ultrasonic sensors 54. Sensing area 101F covers the periphery of the front end of vehicle 1 with multiple ultrasonic sensors 54. Sensing area 101B covers the periphery of the rear end of vehicle 1 with multiple ultrasonic sensors 54.

The sensing results in sensing area 101F and sensing area 101B are used, for example, for parking assistance for vehicle 1.

Sensing area 102F to sensing area 102B show examples of sensing areas of a short-range or medium-range radar 52. Sensing area 102F covers a position farther in front of the vehicle 1 than sensing area 101F. Sensing area 102B covers a position farther in the rear of the vehicle 1 than sensing area 101B. Sensing area 102L covers the rear periphery of the left side of the vehicle 1. Sensing area 102R covers the rear periphery of the right side of the vehicle 1.

The sensing results in sensing area 102F are used, for example, to detect vehicles, pedestrians, etc., that are in front of vehicle 1. The sensing results in sensing area 102B are used, for example, for collision prevention functions behind vehicle 1. The sensing results in sensing area 102L and sensing area 102R are used, for example, to detect objects in blind spots to the sides of vehicle 1.

Sensing area 103F to sensing area 103B show examples of sensing areas by camera 51. Sensing area 103F covers a position farther in front of vehicle 1 than sensing area 102F. Sensing area 103B covers a position farther in the rear of vehicle 1 than sensing area 102B. Sensing area 103L covers the periphery of the left side of vehicle 1. Sensing area 103R covers the periphery of the right side of vehicle 1.

The sensing results in sensing area 103F can be used, for example, for recognizing traffic signals and traffic signs, lane departure prevention support systems, and automatic headlight control systems. The sensing results in sensing area 103B can be used, for example, for parking assistance and surround view systems. The sensing results in sensing area 103L and sensing area 103R can be used, for example, for surround view systems.

Sensing area 104 shows an example of the sensing area of LiDAR 53. Sensing area 104 covers a position farther in front of vehicle 1 than sensing area 103F. On the other hand, sensing area 104 has a narrower range in the left-right direction than sensing area 103F.

The sensing results in the sensing area 104 are used, for example, to detect objects such as surrounding vehicles.

Sensing area 105 shows an example of the sensing area of long-range radar 52. Sensing area 105 covers a position farther in front of vehicle 1 than sensing area 104. On the other hand, sensing area 105 has a narrower range in the left-right direction than sensing area 104.

The sensing results in the sensing area 105 are used, for example, for ACC (Adaptive Cruise Control), emergency braking, collision avoidance, etc.

The sensing areas of the cameras 51, radar 52, LiDAR 53, and ultrasonic sensors 54 included in the external recognition sensor 25 may have various configurations other than those shown in FIG. 2. Specifically, the ultrasonic sensor 54 may also sense the sides of the vehicle 1, and the LiDAR 53 may sense the rear of the vehicle 1. The installation positions of the sensors are not limited to the examples described above. The number of sensors may be one or more.

<<2. First embodiment>>
In recent years, a technology called spatial noise control (hereinafter referred to as spatial NC) has been attracting attention as a technique for creating quiet spaces.

When trying to quiet a space, active control (also called passive control), which is used in conventional headphone NC (Noise Cancelling), is cited as an effective method in the low frequency range where passive control is considered to be less effective.

In recent years, spatial NC is expected to be used in mobility applications in particular. One reason for this is the demand for lightweight vehicle bodies in order to be environmentally friendly for mobility vehicles. In other words, whereas quietness was previously achieved by adding sound-absorbing materials, by reducing weight by removing various components, including sound-absorbing materials, noise caused by body vibrations tends to become more noticeable, and as a result, interest in noise reduction through active control is growing.

There are two main types of active noise reduction methods for the vehicle interior. The first method senses the vibrations of the noise source and, based on the sensing results, plays an inverse phase sound from the speaker at the sound receiving point (control point), such as the listener's ear, to cancel out the noise.

The second method involves sensing the vibrations of the panel that emits (radiates) the noise, and then directly dampening the vibrations of the panel using an actuator (exciter) based on the sensing results.

The first method requires a series of signal processing steps to sense vibrations at the noise source and, based on the sensing results, play back on a speaker an anti-phase sound that cancels out the noise and is heard at the sound receiving point (control point). However, this series of signal processing only needs to be completed before the noise from the noise source is transmitted to the sound receiving point, and is performed using a feedforward method because it is easy to secure the required time.

On the other hand, the second method requires sensing the vibration of the panel that emits the noise and directly dampening the panel with an actuator, and because it is difficult to secure the time required for processing, a feedback method is used.

Hereinafter, the first method, which senses the vibrations of a noise source and plays back from a speaker an anti-phase sound that cancels the noise at the sound receiving point, will be referred to simply as the feedforward method (FF method).

The second method, which senses the vibration of the panel that is emitting the noise and directly controls the vibration of the panel using an actuator (exciter), is also simply called the feedback method (FB method).

First, we will explain the FF type NC device 33 as a configuration example of the first embodiment.

More specifically, as shown in FIG. 3, the FF-type NC device 33 is composed of sensors 151-1 to 151-n, an in-vehicle microphone 152, an NC processing unit 153, and a speaker 154.

Sensors 151-1 to 151-n are acceleration sensors that sense the vibrations of noise source SN and output sensor signals that are the sensing results to NC processing unit 153. Sensors 151-1 to 151-n may be substituted for vehicle sensor 27 as long as they function as acceleration sensors that sense the vibrations of noise source SN.

Hereinafter, when there is no need to distinguish between sensors 151-1 to 151-n, they will be simply referred to as sensor 151, and the same applies to other components. Also, here, sensor 151 is assumed to be an acceleration sensor, but it may be something other than an acceleration sensor as long as it detects information about noise, that is, a physical quantity that can capture phenomena such as vibration that can be the source of noise. That is, sensor 151 may be, for example, a sensor that is generally called a vibration sensor and detects displacement, velocity, and acceleration as all physical quantities that make up vibration. Also, sensor 151 may be any of an acceleration sensor, a displacement sensor, and a velocity sensor. Therefore, the sensor signal may include velocity and displacement in addition to acceleration.

The in-vehicle microphone 152 is a microphone that picks up sound from within the vehicle cabin and is located, for example, on the ceiling or floor, away from the control point EP, which is the position of the user's ear, and outputs the picked-up sound to the NC processing unit 153 as an audio signal.

The NC processing unit 153 reads out a cancellation filter that has been generated in advance in association with the sensor signal, which is the sensing result of the vibration of the noise source SN from the sensors 151-1 to 151-n, and the audio signal from within the vehicle cabin supplied from the vehicle cabin microphone 152, and generates an anti-phase audio AS that cancels (negates) the noise at the control point EP through signal processing using the cancellation filter, and emits the audio from the speaker 154.

With this configuration, at the control point EP, the noise NS generated by the noise source SN is cancelled by the antiphase sound AS emitted from the speaker 154, so the noise heard by the user's ears is reduced. The detailed configuration of the NC processing unit 153 will be described later in detail with reference to FIG. 4.

<Functions realized by NC units>
Next, functions realized by the NC device 33 will be described with reference to Fig. 4. In describing the functions realized by the NC device 33, a configuration example of a filter generation processing unit 181 for generating a cancellation filter used in the NC processing unit 153 will also be described with reference to Fig. 5. In the filter generation processing unit 181 in Fig. 5, components having the same functions as those in the NC processing unit 153 are denoted by the same reference numerals, and descriptions thereof will be omitted as appropriate.

The NC processing unit 153 stores cancellation filters that have been generated in advance by the filter generation processing of the filter generation processing unit 181 (Figure 5), and in the noise cancellation (NC) processing, it reads and uses the cancellation filters that correspond to the sensing results of the sensors 151-1 to 151-n and the sound picked up by the in-vehicle microphone 152, generates sound that is in the opposite phase to the picked up sound, and emits it from the speaker 154.

More specifically, the NC processing unit 153 includes a sensor filter design unit 171, a sensor filter set storage unit 172, a cancellation filter set storage unit 173, a corresponding filter acquisition unit 174, and an NC signal calculation unit 175.

The filter generation processing unit 181 (FIG. 5) includes a sensor filter design unit 171, a sensor filter set storage unit 172, a cancellation filter set storage unit 173, a correspondence storage processing unit 192, and a cancellation filter design unit 191. The filter generation processing unit 181 also receives audio at the control points picked up by a control point proximity microphone 182 that is installed at the control points only during the filter generation processing.

The sensor filter design unit 171 designs an NC filter as a sensor filter that generates an anti-phase sound to cancel the sound picked up by the in-vehicle microphone 152 based on the sensing results of the sensors 151-1 to 151-n and the sound picked up by the in-vehicle microphone 152, both during the filter generation process and the noise cancellation process.

During the filter generation process, the cancellation filter design unit 191 designs an NC filter as a cancellation filter that generates an anti-phase sound to cancel the sound picked up by the in-vehicle microphone 152, based on the sensing results of the sensors 151-1 to 151-n and the sound picked up by the control point proximity microphone 182.

The control point is the position of the ear heard by the user, and is the position where noise is to be cancelled during noise cancellation processing. However, since the user is present during noise cancellation, it is often not possible to properly position the control point proximity microphone 182. For this reason, by placing the control point proximity microphone 182 at the control point only during the filter generation processing, sound is picked up at the position where noise is to be cancelled, and a cancellation filter is designed in advance based on the sound picked up at the control point.

The sensor filter design unit 171 and the cancellation filter design unit 191 both have the same basic configuration, and for example, as shown in Figure 6, are equipped with an LMS (Least Mean Square) algorithm processing unit 201.

The LMS algorithm processing unit 201 designs (generates) a sensor filter 203 that generates, in real time, an anti-phase sound that cancels the sound picked up by the in-vehicle microphone 152, which is an error microphone, while driving with variously changing tire and road surface conditions.

In this case, the LMS algorithm processing unit 201 designs the sensor filter 203 using the LMS algorithm based on the secondary path transfer characteristic S between the cancellation speaker 202, which corresponds to the speaker 154, and the in-vehicle microphone 152 and the estimated or measured value S^ of the secondary path transfer characteristic (S with a hat in the figure).

Similarly, in the cancellation filter design unit 191, the LMS algorithm processing unit 201 designs a cancellation filter 203 that generates an antiphase sound that cancels the sound picked up by the control point proximity microphone 182, which is the error microphone, in real time when driving with variously changing tire and road conditions, based on the secondary path transfer characteristic S between the cancellation speaker 202 corresponding to the speaker 154 and the control point proximity microphone 182 and the estimated or measured value S^ of the secondary path transfer characteristic.

In addition, the algorithm for designing the sensor filter and the cancellation filter may be an algorithm other than the LMS algorithm, such as the NLMS (Normalized LMS) algorithm, the RLS (Recursive Least Square) algorithm, and the conjugate gradient algorithm.

The correspondence storage processing unit 192 (Figure 5) associates the sensor filters and cancellation filters generated by the sensor filter design unit 171 and the cancellation filter design unit 191, respectively, with each other during the filter generation process, for example by assigning corresponding IDs, and stores them in the sensor filter set storage unit 172 and the cancellation filter set storage unit 173, respectively.

During real-time operation, the trigger for the association storage processing unit 192 to associate and store a set of sensor filters and cancellation filters is a timing when the rate of change of the filter coefficients is small and stable. More specifically, the trigger for storing a set of sensor filters and cancellation filters in association is the timing when it is detected that the rate of change between steps of the filter coefficients is less than a certain value, or the timing when it is detected that the rate of change over time of the RMS value of the error microphone signal has fallen below a predetermined value.

Furthermore, the generation of the sensor filter and cancellation filter does not necessarily have to be done in real time. A log recording all sensing results of the control point proximity microphone 182, the in-vehicle microphone 152, and the sensors 151-1 to 151-n may be collected each time the vehicle is driven under different tire and road surface conditions, and the sensor filter and cancellation filter may be generated by offline operation using the log. In this case, an ID may be assigned to each different tire and road surface condition, and the sensor filter and cancellation filter may be stored in association with each other as a set.

When the corresponding filter acquisition unit 174 of the NC processing unit 153 acquires a sensor filter designed by the sensor filter design unit 171 based on the sensing results of the sensors 151-1 to 151-n and the sound picked up by the in-vehicle microphone 152 during noise cancellation processing, the corresponding filter acquisition unit 174 searches for a corresponding sensor filter from the sensor filter set stored in the sensor filter set storage unit 172. The corresponding filter acquisition unit 174 then searches for a cancellation filter assigned an ID corresponding to the searched sensor filter from the cancellation filter set storage unit 173, and outputs the cancellation filter to the NC signal calculation unit 175.

The method by which the corresponding filter acquisition unit 174 selects a cancellation filter with a corresponding ID from the generated sensor filters during noise cancellation processing may be a method of directly calculating the Euclidean distance between filter coefficients, or a method of converting to coefficients on the frequency axis using FFT or the like and then calculating the distance. If the frequencies that should be emphasized differ between the cancellation filter and the sensor filter, it is desirable to use a distance measure that maximizes the effect of noise cancellation, such as by weighting the distance calculation by frequency.

The NC signal calculation unit 175 executes NC (noise cancellation) signal calculation processing based on the cancellation filter supplied by the corresponding filter acquisition unit 174, generates anti-phase audio for canceling the audio at the control point, and emits the audio from the speaker 154.

With this configuration, even if the control point proximity microphone 182 is not installed during noise cancellation, the in-vehicle microphone 152 can be used to indirectly determine the optimal cancellation filter at the control point proximity position that tracks changes in the road surface and tire conditions.

As a result, it is possible to achieve highly accurate noise cancellation processing of the control point simply by placing the in-vehicle microphone 152 at any position away from the ear, which is the control point. Also, simply placing the in-vehicle microphone 152 without providing a control point proximity microphone 182 makes it possible to obtain a sufficient noise canceling effect against high-frequency noise.

<Filter Generation Processing by the Filter Generation Processing Unit in FIG. 5>
Next, the filter generation process by the filter generation processing unit 181 in Fig. 5 will be described with reference to the flowchart in Fig. 7. Note that this process is performed while the vehicle 1 is traveling with various changes in tire and road surface conditions, with the filter generation processing unit 181 in Fig. 5 mounted on the vehicle 1 in place of the NC device 33. However, when the information detected by the sensors 151-1 to 151-n, the in-vehicle microphone 152, and the control point proximity microphone 182 is all left as a log as the vehicle 1 travels, it is also possible to perform the process offline by utilizing the information.

In step S31, the sensor filter design unit 171 and the cancellation filter design unit 191 of the filter generation processing unit 181 acquire sensor signals consisting of the sensing results supplied from the sensors 151-1 to 151-n.

In step S32, the sensor filter design unit 171 acquires the sound as noise picked up by the in-vehicle microphone 152 as an input signal.

In step S33, the sensor filter design unit 171 designs an NC filter for generating sound in the opposite phase to the sound as noise from the sensor signals consisting of the sensing results supplied from the sensors 151-1 to 151-n and the input signal of the sound as noise picked up by the in-vehicle microphone 152, and outputs it as a sensor filter.

In step S34, the cancellation filter design unit 191 acquires the noise-based audio picked up by the control point proximity microphone 182 as an input signal.

In step S35, the cancellation filter design unit 191 designs an NC filter that generates a sound in the opposite phase to the sound as noise from the sensor signals formed by the sensing results supplied from the sensors 151-1 to 151-n and the input signal of the sound as noise picked up by the control point proximity microphone 182, and outputs it as a cancellation filter.

In step S36, the correspondence storage processing unit 192 associates the sensor filter designed by the sensor filter design unit 171 with the cancellation filter designed by the cancellation filter design unit 191, and stores them in the sensor filter set memory unit 172 and the cancellation filter set memory unit 173, respectively.

The correspondence storage processing unit 192, for example, assigns a common ID to each of the sensor filter designed by the sensor filter design unit 171 and the cancellation filter designed by the cancellation filter design unit 191, and stores them in the sensor filter set storage unit 172 and the cancellation filter set storage unit 173, respectively, in correspondence with each other.

In step S37, the sensor filter design unit 171 and the cancellation filter design unit 191 determine whether or not an instruction to end the process has been given. If an instruction to end the process has not been given, the process returns to step S31, and the subsequent processes are repeated.

Then, in step S37, if an instruction to end is given, the process ends.

By the above process, when the control point proximity microphone 182 is installed, a cancellation filter set for canceling noise detected at the control point is generated and stored in association with a sensor filter set for canceling noise detected by the in-vehicle microphone 152.

In other words, in the above-mentioned filter generation process, the sensor filter for generating audio of the opposite phase to the audio picked up by the in-vehicle microphone 152 is required as the label of the cancellation filter for generating audio of the opposite phase at the control point that is the target of NC processing consisting of the same sensor signal and the audio picked up by the control point proximity microphone 182. Therefore, by storing the sensor filter and the cancellation filter in correspondence with each other, the cancellation filter is assigned a label consisting of the sensor filter and stored.

<NC processing by the NC unit in Figure 4>
Next, the NC processing by the NC device 33 in Fig. 4 will be described with reference to the flowchart in Fig. 8. Note that this processing is premised on the fact that the sensor filters and cancellation filters have been associated with each other and stored in the sensor filter set storage unit 172 and the cancellation filter set storage unit 173 by the processing described with reference to the flowchart in Fig. 7.

In step S51, the sensor filter design unit 171 and the NC signal calculation unit 175 of the NC processing unit 153 acquire sensor signals consisting of the sensing results supplied from the sensors 151-1 to 151-n.

In step S52, the sensor filter design unit 171 acquires the sound as noise picked up by the in-vehicle microphone 152 as an input signal.

In step S53, the sensor filter design unit 171 designs an NC filter for generating sound in antiphase with the sound as noise from the sensor signals consisting of the sensing results supplied from the sensors 151-1 to 151-n and the input signal of the sound as noise picked up by the in-vehicle microphone 152, and outputs it as a sensor filter.

In step S54, the corresponding filter acquisition unit 174 acquires the sensor filter designed by the sensor filter design unit 171, and searches for and acquires the corresponding stored cancellation filter from the cancellation filter set storage unit 173.

More specifically, the corresponding filter acquisition unit 174 searches the sensor filter set storage unit 172 for a sensor filter that corresponds to the sensor filter designed by the sensor filter design unit 171.

Then, the corresponding filter acquisition unit 174 reads out the cancellation filter stored in association with the ID of the searched sensor filter from the cancellation filter set storage unit 173 and outputs it to the NC signal calculation unit 175.

In step S55, the NC signal calculation unit 175 uses the cancellation filter provided by the corresponding filter acquisition unit 174 and the sensor signals formed from the sensing results provided by the sensors 151-1 to 151-n to generate sound that is in antiphase with the noise estimated to be observed at the control point, and emits the sound from the speaker 154 to achieve NC processing.

In step S56, the sensor filter design unit 171 and the NC signal calculation unit 175 determine whether or not an instruction to end the process has been given. If an instruction to end the process has not been given, the process returns to step S51 and the subsequent processes are repeated.

Then, in step S56, if termination is instructed, the process ends.

As described above, the cancellation filter for generating audio in phase with the control point by the filter generation process is stored in a state labeled with a sensor filter. Therefore, in the NC process, by reading and using a cancellation filter labeled with a sensor filter determined from the audio picked up by the in-vehicle microphone 152 and the sensor signal, it is possible to generate and emit audio in phase with the control point of the corresponding conditions, thereby achieving appropriate NC processing.

As a result, during NC processing, even if the control point proximity microphone 182 is not installed, a cancellation filter set for canceling noise detected at the control point, which has been generated in advance by the filter generation process, is used to generate anti-phase sound that cancels the noise at the control point, and this sound is emitted from the speaker 154, making it possible to reduce the noise at the control point.

It can be said that through the above processing, the sensor filter design unit 171 and the corresponding filter acquisition unit 174, which are surrounded by dotted lines in FIG. 4, realize the function of providing the NC signal calculation unit 175 with a cancellation filter at the control point based on the sensor signals of the sensors 151-1 to 151-n and the input signal of the sound as noise picked up by the in-vehicle microphone 152.

<<3. First Modification of the First Embodiment>>
In the above, an example configuration of the NC device 33 has been described in which, during the filter generation process, a sensor filter for canceling noise picked up by the in-vehicle microphone 152 is generated and stored in association with a cancellation filter for canceling noise picked up by the control point proximity microphone 182, and, during the NC process, the cancellation filter stored in association with the sensor filter for canceling noise picked up by the in-vehicle microphone 152 is read out and a sound that is in antiphase with the noise at the control point is generated and emitted, thereby enabling the noise at the control point to be appropriately canceled even when the control point proximity microphone 182 is not present.

However, for example, when driving through a tunnel, noise transmitted from outside the vehicle cabin to the vehicle cabin may be louder than normal. In this case, the vehicle cabin microphone 152 receives a roaring noise that is unrelated to changes in the road surface or tire conditions, which may cause the accuracy of the filter design in the sensor filter design unit 171 to deteriorate.

In this regard, an exterior microphone may be provided to pick up noise outside the vehicle cabin, and the noise components outside the vehicle cabin picked up by the exterior microphone may be removed from the noise detected by the interior microphone 152, thereby reducing the adverse effects that may be caused by noise such as explosions occurring outside the vehicle.

Figures 9 and 10 show example configurations of an NC unit 33 and a filter generation processing unit 181, respectively, in which a microphone is newly installed outside the vehicle cabin.

In the NC device 33 in FIG. 9 and the filter generation processing unit 181 in FIG. 10, components having the same functions as those in the NC device 33 in FIG. 4 and the filter generation processing unit 181 in FIG. 5 are given the same reference numerals, and their description will be omitted.

The NC device 33 in FIG. 9 and the filter generation processing unit 181 in FIG. 10 differ from the NC device 33 in FIG. 4 and the filter generation processing unit 181 in FIG. 5 in that they each newly include an exterior microphone 211 and calculators 212, 212-1, and 212-2.

The exterior microphone 211 is installed in a position that is less susceptible to wind and rain while driving, such as the rear of the vehicle 1, and picks up noise outside the vehicle and supplies the noise to the calculators 212, 212-1, and 212-2.

The calculators 212, 212-1, and 212-2 estimate components that are uncorrelated with the sensor signals (components of pure noise outside the vehicle cabin) that are the sensing results of the sensors 151-1 to 151-n and that are picked up by the exterior microphone 211.

Furthermore, the calculators 212, 212-1, and 212-2 subtract and remove the noise components outside the vehicle cabin that correspond to the noise outside the vehicle cabin supplied from the exterior microphone 211 from the noise inside the vehicle cabin supplied from the interior microphone 152, extract the noise components inside the vehicle cabin, and supply them to the sensor filter design unit 171 and the cancellation filter design unit 191.

This configuration makes it possible to reduce the adverse effects on the sensor filter design unit 171 and the cancellation filter design unit 191 of noise components outside the vehicle cabin that are transmitted into the vehicle cabin and picked up by the in-vehicle microphone 152.

The NC processing and filter generation processing by the NC device 33 in FIG. 9 and the filter generation processing unit 181 in FIG. 10 are the same as the NC processing and filter generation processing described with reference to the flowcharts in FIG. 7 and FIG. 8, except that the noise components outside the vehicle cabin are estimated from the signal of the noise outside the vehicle cabin picked up by the exterior microphone 211 and are subtracted and removed from the noise inside the vehicle cabin picked up by the interior microphone 152, so a description thereof will be omitted.

<<4. Second Modification of the First Embodiment>>
The above has described an example in which the adverse effects of noise outside the vehicle cabin are reduced by providing an exterior microphone 211 and subtracting and removing the noise components outside the vehicle cabin from the noise inside the vehicle cabin picked up by the interior microphone 152.

However, there are cases where the sounds (noise) outside the vehicle cabin are unavoidably loud, such as honking or the sound of a nearby large truck passing by. In such cases, the influence of the noise outside the vehicle cabin becomes dominant over the input to the in-vehicle microphone 152, and it may not be possible to sufficiently reduce the adverse effects of the noise outside the vehicle cabin simply by estimating and subtracting the noise components outside the vehicle cabin input by the in-vehicle microphone 152 using the calculators 212, 212-1, and 212-2.

Sensor filters and cancellation filters basically cancel noise by emitting audio that is in the opposite phase to the noise generated inside the vehicle cabin. Therefore, if a sudden loud sound outside the vehicle causes an inappropriate audio to be generated and emitted as an audio that is in the opposite phase to the noise inside the vehicle cabin, there is a risk that the audio that is emitted will be recognized as noise by the user.

Therefore, during the filter generation process, when the noise outside the vehicle cabin is equal to or greater than a predetermined sound pressure level, the sensor filter design unit 171 and the cancellation filter design unit 191 may not design a filter. Correspondingly, during NC processing, the NC processing may be stopped or the immediately preceding cancellation filter may be used as is.

FIG. 11 shows an example of the configuration of the NC device 33 that stops NC processing or uses the previous cancellation filter as is when the noise outside the vehicle cabin exceeds a predetermined sound pressure level during NC processing.

FIG. 12 also shows an example of the configuration of a filter generation processing unit 181 that, when generating a filter, does not design filters in the sensor filter design unit 171 and the cancellation filter design unit 191 when the noise outside the vehicle cabin is equal to or greater than a predetermined sound pressure level, and stores the results in the sensor filter set storage unit 172 and the cancellation filter set storage unit 173 of the NC device 33 in FIG. 11.

In the NC device 33 in FIG. 11 and the filter generation processing unit 181 in FIG. 12, components having the same functions as those in the NC device 33 in FIG. 9 and the filter generation processing unit 181 in FIG. 10 are given the same reference numerals, and their description will be omitted.

The NC device 33 in FIG. 11 and the filter generation processing unit 181 in FIG. 12 differ from the NC device 33 in FIG. 9 and the filter generation processing unit 181 in FIG. 10 in that both are newly equipped with an external sound determination unit 221.

The exterior sound determination unit 221 calculates the sound pressure level outside the vehicle cabin by performing a sound pressure level calculation process for the noise outside the vehicle cabin, and when the sound pressure level of the noise outside the vehicle cabin is greater than a predetermined threshold value as a result of comparison with the predetermined threshold value, it stops the operation of the sensor filter design unit 171 and the cancellation filter design unit 191.

More specifically, the external sound determination unit 221 calculates the average sound pressure level every second, for example, in a specific band or in the entire band, and in the threshold determination, determines whether the average sound pressure level is greater than a predetermined threshold. If it is greater than the predetermined threshold, the sensor filter design unit 171 and the cancellation filter design unit 191 stop designing the sensor filter and the cancellation filter.

On the other hand, if the average sound pressure level is smaller than the predetermined threshold, the sensor filter and cancellation filter are designed in the sensor filter design unit 171 and the cancellation filter design unit 191, and the sensor filter and cancellation filter are stored in association with each other in the sensor filter set storage unit 172 and the cancellation filter set storage unit 173, respectively.

The specified threshold value may be determined in advance by measuring, for example, the noise levels of jet engine sounds, train whistles, horns, sirens, and the passing of large trucks, which are likely to have adverse effects.

In addition, in addition to using the average sound pressure level, the comparison with the predetermined threshold value may be made using the cross-correlation between the signals input to the in-vehicle microphone 152 and the outside-vehicle microphone 211.

For example, when the noise outside the vehicle cabin is loud or when the vehicle windows are open, the effect of the noise outside the vehicle cabin on the in-vehicle microphone 152 becomes dominant, and the correlation between the input signals to the in-vehicle microphone 152 and the in-vehicle microphone 211 becomes large.

The vehicle exterior sound determination unit 221 therefore calculates the cross-correlation between the input signals to the vehicle interior microphone 152 and the vehicle exterior microphone 211, and when the cross-correlation is greater than a predetermined threshold (for example, there is a strong correlation of 0.7 or more), it may determine that the noise outside the vehicle is large and may adversely affect the filter design, and may stop the design of the sensor filter and the cancellation filter in the sensor filter design unit 171 and the cancellation filter design unit 191.

The vehicle exterior sound determination unit 221 in Figures 11 and 12 is configured to be able to acquire input signals from both the vehicle interior microphone 152 and the vehicle exterior microphone 211, and may use either the average sound pressure level of the noise outside the vehicle interior or the cross-correlation of the input signals from the vehicle interior microphone 152 and the vehicle exterior microphone 211 described above to compare the level of the noise outside the vehicle interior with a predetermined threshold value, or may use both to make a determination.

<Filter Generation Processing by the Filter Generation Processing Unit in FIG. 12>
Next, the filter generation process performed by the filter generation processing unit 181 in FIG. 12 will be described with reference to the flowchart in FIG.

In step S71, the sensor filter design unit 171 and the cancellation filter design unit 191 of the filter generation processing unit 181 acquire sensor signals consisting of the sensing results supplied from the sensors 151-1 to 151-n.

In step S72, the calculator 212-1 estimates the noise components outside the vehicle cabin in the input signal of the voice as noise inside the vehicle cabin picked up by the interior microphone 152 based on the input signal of the voice as noise outside the vehicle cabin picked up by the exterior microphone 211, subtracts and corrects the noise components, and supplies the result to the sensor filter design unit 171.

In step S73, the vehicle exterior sound determination unit 221 calculates an average sound pressure level based on the input signal of the audio signal representing noise outside the vehicle cabin picked up by the vehicle exterior microphone 211. Alternatively, the vehicle exterior sound determination unit 221 calculates the cross-correlation between the input signal of the audio representing noise outside the vehicle cabin picked up by the vehicle exterior microphone 211 and the input signal of the audio representing noise inside the vehicle cabin picked up by the vehicle interior microphone 152.

In step S74, the external sound determination unit 221 determines whether the average sound pressure level or cross-correlation is greater than a predetermined threshold and whether the noise outside the vehicle cabin is greater than a predetermined level.

If, in step S74, the average sound pressure level or cross-correlation is less than a predetermined threshold and the noise outside the vehicle cabin is deemed to be less than a predetermined level, processing proceeds to step S75.

In step S75, the sensor filter design unit 171 designs an NC filter from the sensor signals consisting of the sensing results supplied from the sensors 151-1 to 151-n and the input signal of the corrected sound picked up by the in-vehicle microphone 152 as noise, and outputs it as a sensor filter.

In step S76, the calculator 212-2 estimates the noise components outside the vehicle cabin in the input signal of the sound as noise at the control point picked up by the control point proximity microphone 182 based on the input signal of the sound as noise outside the vehicle cabin picked up by the exterior microphone 211, subtracts and corrects the noise components, and supplies the result to the cancellation filter design unit 191.

In step S77, the cancellation filter design unit 191 designs an NC filter from the sensor signals formed by the sensing results supplied from the sensors 151-1 to 151-n and the corrected input signal of the sound as noise picked up by the control point proximity microphone 182, and outputs it as a cancellation filter.

In step S78, the correspondence storage processing unit 192 associates the sensor filter designed by the sensor filter design unit 171 with the cancellation filter designed by the cancellation filter design unit 191, and stores them in the sensor filter set memory unit 172 and the cancellation filter set memory unit 173, respectively.

On the other hand, if in step S74 the average sound pressure level or cross-correlation is greater than the predetermined threshold and the noise outside the vehicle cabin is deemed to be greater than the predetermined level, the processing of steps S75 to S78 is skipped. In other words, if the noise outside the vehicle cabin is deemed to be greater than the predetermined level, the design of the sensor filter and cancellation filter is stopped because there is a possibility that the noise outside the vehicle cabin will adversely affect the sensor filter and cancellation filter to be designed.

In step S79, the sensor filter design unit 171 and the cancellation filter design unit 191 determine whether or not an instruction to end the process has been given. If an instruction to end the process has not been given, the process returns to step S71, and the subsequent processes are repeated.

Then, in step S79, if an instruction to end is given, the process ends.

By the above process, when the control point proximity microphone 182 is installed, a cancellation filter set for canceling noise detected at the control point is generated and stored in association with a sensor filter set for canceling noise detected by the in-vehicle microphone 152. At this time, when the level of noise outside the vehicle cabin is deemed to be greater than a predetermined level, the design of the sensor filter and cancellation filter is stopped, so that an inappropriate cancellation filter that would be adversely affected is not designed (generated).

<NC processing by the NC device in FIG. 11>
Next, the NC processing by the NC device 33 in Fig. 4 will be described with reference to the flowchart in Fig. 14. Note that this processing is premised on the fact that the sensor filters and cancellation filters have been associated with each other and stored in the sensor filter set storage unit 172 and the cancellation filter set storage unit 173 by the processing described with reference to the flowchart in Fig. 7.

In step S91, the sensor filter design unit 171 and the NC signal calculation unit 175 of the NC processing unit 153 acquire sensor signals consisting of the sensing results supplied from the sensors 151-1 to 151-n.

In step S92, the calculator 212 estimates the noise components outside the vehicle cabin in the input signal of the voice as noise inside the vehicle cabin picked up by the interior microphone 152 based on the input signal of the voice as noise outside the vehicle cabin picked up by the exterior microphone 211, subtracts and corrects the estimated noise components, and supplies the result to the sensor filter design unit 171.

In step S93, the vehicle exterior sound determination unit 221 calculates an average sound pressure level based on the input signal of the audio signal representing noise outside the vehicle cabin picked up by the vehicle exterior microphone 211. Alternatively, the vehicle exterior sound determination unit 221 calculates the cross-correlation between the input signal of the audio signal representing noise outside the vehicle cabin picked up by the vehicle exterior microphone 211 and the input signal of the audio signal representing noise inside the vehicle cabin picked up by the vehicle interior microphone 152.

In step S94, the external sound determination unit 221 determines whether the average sound pressure level or cross-correlation is greater than a predetermined threshold and whether the noise outside the vehicle cabin is greater than a predetermined level.

If, in step S94, the average sound pressure level or cross-correlation is less than a predetermined threshold and the noise outside the vehicle cabin is deemed to be less than a predetermined level, processing proceeds to step S95.

In step S95, the sensor filter design unit 171 designs an NC filter from the sensor signals formed by the sensing results supplied from the sensors 151-1 to 151-n and the input signal, which is the corrected audio signal as noise picked up by the in-vehicle microphone 152, and outputs it as a sensor filter.

In step S96, the corresponding filter acquisition unit 174 acquires the sensor filter designed by the sensor filter design unit 171, searches for and acquires the corresponding stored cancellation filter from the cancellation filter set storage unit 173, and outputs it to the NC signal calculation unit 175.

In step S97, the NC signal calculation unit 175 uses the cancellation filter provided by the corresponding filter acquisition unit 174 and the sensor signal formed from the sensing results provided by the sensors 151-1 to 151-n to generate a sound that is in antiphase with the noise estimated to be observed at the control point, and emits the sound from the speaker 154.

In step S94, if the external sound determination unit 221 determines that the average sound pressure level or cross-correlation is greater than a predetermined threshold and that the noise outside the vehicle cabin is greater than a predetermined level, steps S95 to S97 are skipped. In other words, if the average sound pressure level or cross-correlation is greater than a predetermined threshold and that the noise outside the vehicle cabin is greater than a predetermined level, a corresponding cancellation filter has not been generated, so the NC processing is essentially stopped. Note that, although an example in which the NC processing is stopped is described here, the cancellation filter used immediately before may be used as is.

In step S98, the sensor filter design unit 171 and the NC signal calculation unit 175 determine whether or not an instruction to end the process has been given. If an instruction to end the process has not been given, the process returns to step S91 and the subsequent processes are repeated.

Then, in step S98, if termination is instructed, the process ends.

By the above process, even when the control point proximity microphone 182 is not installed, a cancellation filter set for canceling noise detected at the control point, which has been generated in advance by the filter generation process, is used to generate anti-phase sound that cancels the noise at the control point, and this sound is emitted from the speaker 154, making it possible to reduce the noise at the control point. Also, when the level of noise outside the vehicle cabin, such as a siren, whistle, horn, or inside a tunnel, is deemed to be greater than a predetermined level, the NC process using the cancellation filter is stopped, so that a cancellation filter that has been adversely affected and generated with an inappropriate design is not used.

Note that, although an example is described here in which the NC process stops when the noise outside the vehicle cabin is deemed to be greater than a predetermined level, the cancellation filter that was used immediately before may be used as is.

<<5. Third Modification of the First Embodiment>>
In the above, an example has been described in which a sensor filter and a cancellation filter are designed in advance in correspondence with each other during the filter generation process, a cancellation filter corresponding to the sensor filter designed during NC processing is read out, and an anti-phase sound is generated and emitted using the read cancellation filter, thereby achieving NC.

However, the following configuration may also be used. That is, the noise inside the vehicle cabin picked up by the in-vehicle microphone 152 when the filter is generated and the sensor signals resulting from sensing by the sensors 151-1 to 151-n are used as student data, and a cancellation filter that generates sound with an opposite phase at the control point and its ID are used as teacher data, and a trained model that infers the ID of the cancellation filter that generates sound with an opposite phase at the control point is generated by pre-training.

Then, during NC processing, the pre-generated trained model is used to infer the ID of a cancellation filter that generates an anti-phase sound at the control point from the noise inside the vehicle cabin picked up by the vehicle cabin microphone 152 when the filter is generated and the sensor signals that are the sensing results of the sensors 151-1 to 151-n, and the cancellation filter that corresponds to the ID that is the inferred result is searched for and read out, and the anti-phase sound at the control point is generated and emitted, thereby achieving NC processing at the control point.

FIG. 15 shows an example configuration 153' of an NC processing unit that, during NC processing, infers the ID of a cancellation filter for generating antiphase sound at a control point from noise inside the vehicle cabin and sensor signals using a trained model, searches for and reads out a cancellation filter that corresponds to the inferred ID, and performs NC processing using the read cancellation filter.

FIG. 16 also shows an example of the configuration of a filter generation processing unit 181' that, during filter generation processing, designs a cancellation filter for generating antiphase sound at a control point from the noise at the control point and the sensor signal, stores the cancellation filter in association with an ID, and learns and stores a trained model that infers the ID of the cancellation filter from the noise in the vehicle cabin and the sensor signal.

The NC processing unit 153 ′ in FIG. 15 includes a DNN inference unit 251 , a learned model memory unit 252 , a filter search unit 253 , a cancellation filter set memory unit 254 , and an NC signal calculation unit 255 .

Note that the cancellation filter set storage unit 254 and the NC signal calculation unit 255 have the same configuration as the cancellation filter set storage unit 173 and the NC signal calculation unit 175, so their description will be omitted.

When a filter is generated by the filter generation processing unit 181' in FIG. 16, the DNN inference unit 251 reads out a learned model stored in the learned model storage unit 252, which consists of a DNN (Deep Neural Network) generated by machine learning performed in the DNN learning unit 273.

Then, the DNN inference unit 251 functions based on the learned model, and infers the ID of a cancellation filter for generating anti-phase sound at the control point based on the noise inside the vehicle cabin picked up by the in-vehicle microphone 152 and the sensor signals of the sensors 151-1 to 151-n, and outputs the inferred ID to the filter search unit 253.

For this reason, the DNN inference unit 251 outputs the ID of the cancellation filter to the filter search unit 253 as an inference result to generate anti-phase audio at the control point from the noise and sensor signal inside the vehicle cabin.

The filter search unit 253 accesses the cancellation filter set storage unit 254, searches for a cancellation filter stored in association with the ID supplied by the DNN inference unit 251, and supplies the searched cancellation filter to the NC signal calculation unit 255.

The filter generation processing unit 181' in FIG. 16 includes a trained model storage unit 252, a cancellation filter set storage unit 254, a cancellation filter design unit 271, a filter recording control unit 272, and a DNN learning unit 273.

Note that the cancellation filter design unit 271 is similar to the cancellation filter design unit 191 in FIG. 12, so its description will be omitted.

The filter recording control unit 272 stores the cancellation filter supplied from the cancellation filter design unit 271 in the cancellation filter set storage unit 254. More specifically, when the filter recording control unit 272 detects that the rate of change between steps of the filter coefficient of the generated cancellation filter is less than a certain value, or when it detects that the rate of change over time of the RMS value of the audio signal of the noise picked up by the control point proximity microphone 182 has fallen below a predetermined value, the filter recording control unit 272 records the cancellation filter in association with the ID in the cancellation filter set storage unit 254, and further outputs the cancellation filter as teacher data for the DNN learning unit 273.

It is desirable to consider minimizing the degradation of performance of NC processing due to errors in the inference results of the DNN inference unit 251, such as arranging the IDs associated with the cancellation filters according to the similarity of the cancellation filters so that similar cancellation filters have close IDs, or using a quantity that correlates with the distance measure between cancellation filters as the ID.

The DNN learning unit 273 uses the noise inside the vehicle cabin picked up by the in-vehicle microphone 152 and the sensor signal as student data, learns the cancellation filter that generates the antiphase sound at the control point and its ID as teacher data, generates a learned model by pre-learning that infers the ID of the cancellation filter that generates the antiphase sound at the control point, and stores it in the learned model storage unit 252.

<Filter Generation Processing by the Filter Generation Processing Unit in FIG. 16>
Next, the filter generation process performed by the filter generation processing unit 181' in FIG. 16 will be described with reference to the flowchart in FIG.

In step S111, the DNN learning unit 273 and the cancellation filter design unit 271 of the filter generation processing unit 181' acquire sensor signals consisting of the sensing results supplied from the sensors 151-1 to 151-n.

In step S112, the cancellation filter design unit 271 acquires the noise-based audio picked up by the control point proximity microphone 182 as an input signal.

In step S113, the cancellation filter design unit 271 designs an NC filter from the input signal, which is the sensor signal formed by the sensing results supplied from the sensors 151-1 to 151-n and the audio signal as noise picked up by the control point proximity microphone 182, and outputs it as a cancellation filter.

In step S114, the filter recording control unit 272 associates the cancellation filter designed by the cancellation filter design unit 271 with an ID, stores the cancellation filter in the cancellation filter set storage unit 254, and outputs the cancellation filter ID to the DNN learning unit 273 as teacher data.

In step S115, the DNN learning unit 273 acquires the noise-containing sound picked up by the in-vehicle microphone 152 as an input signal.

In step S116, the DNN learning unit 273 uses the sensor signals consisting of the sensing results supplied from the sensors 151-1 to 151-n and the input signal of the sound as noise picked up by the in-vehicle microphone 152 as student data, and the cancellation filter and its ID supplied from the filter recording control unit 272 as teacher data, and machine-learns a learned model that infers the ID of the cancellation filter for generating anti-phase sound at the control point from the sensor signal and the input signal of the sound as noise picked up by the in-vehicle microphone 152, and stores the learned model in the learned model storage unit 252.

In step S117, the DNN learning unit 273 and the cancellation filter design unit 271 determine whether or not an instruction to end the process has been given. If an instruction to end the process has not been given, the process returns to step S111, and the subsequent processes are repeated.

Then, in step S117, if an instruction to end is given, the process ends.

By the above process, with the control point proximity microphone 182 installed, a cancellation filter for canceling the noise detected at the control point is designed in association with the ID. In addition, machine learning is performed using the designed cancellation filter and its ID as teacher data and the noise detected by the in-vehicle microphone 152 and the sensor signals of sensors 151-1 to 151-n as student data. This machine learning generates a trained model that infers the ID of a cancellation filter for generating sound that is inverse phase to the noise at the control point, from the noise detected by the in-vehicle microphone 152 and the sensor signals of sensors 151-1 to 151-n.

<NC processing by the NC device in FIG. 15>
Next, the NC processing by the NC device 33 in Fig. 15 will be described with reference to the flowchart in Fig. 18. Note that this processing is premised on the fact that the cancellation filter has been designed by the processing described with reference to the flowchart in Fig. 17 and stored in the cancellation filter set storage unit 254.

In step S131, the DNN inference unit 251 and the NC signal calculation unit 255 of the NC processing unit 153' acquire sensor signals consisting of the sensing results supplied from the sensors 151-1 to 151-n.

In step S132, the DNN inference unit 251 acquires the noise-containing sound picked up by the in-vehicle microphone 152 as an input signal.

In step S133, the DNN inference unit 251 reads out the learned model stored in the learned model storage unit 252, and infers a cancellation filter and its ID for generating anti-phase sound at the control point from the sensor signals consisting of the sensing results supplied from the sensors 151-1 to 151-n and the input signal of the noise picked up by the in-vehicle microphone 152, and outputs the ID of the cancellation filter that is the inferred result to the filter search unit 253.

In step S134, the filter search unit 253 acquires the ID supplied by the DNN inference unit 251, searches the cancellation filter set storage unit 254 for a cancellation filter stored in association with the acquired ID, and outputs the searched cancellation filter to the NC signal calculation unit 255.

In step S135, the NC signal calculation unit 255 uses the cancellation filter provided by the filter search unit 253 and the sensor signals formed from the sensing results provided by the sensors 151-1 to 151-n to generate sound that is in antiphase with the noise estimated to be observed at the control point, and emits the sound from the speaker 154.

In step S136, the DNN inference unit 251 and the NC signal calculation unit 255 determine whether or not an instruction to end the process has been given. If an instruction to end the process has not been given, the process returns to step S111, and the subsequent processes are repeated.

Then, in step S136, if an instruction to end is given, the process ends.

By the above process, the ID of the cancellation filter is inferred from the noise inside the vehicle cabin and the sensor signal, and a cancellation filter registered in association with the inferred cancellation filter ID is used to generate an anti-phase sound that cancels the noise at the control point. This sound is then emitted from speaker 154, making it possible to reduce the noise at the control point.

Furthermore, through the above processing, the DNN inference unit 251 and the filter search unit 253 enclosed by the dotted line in FIG. 15 can be said to realize the function of providing the NC signal calculation unit 175 with a cancellation filter at the control point based on the sensor signals of the sensors 151-1 to 151-n and the input signal of the sound as noise picked up by the in-vehicle microphone 152.

<<6. Fourth Modification of the First Embodiment>>
In the above, an example has been described in which a cancellation filter is generated during the filter generation process, and a trained model is generated by machine learning to infer the ID of the cancellation filter based on the noise in the vehicle cabin and the sensor signal, and during the NC process, the ID of the cancellation filter is inferred based on the noise in the vehicle cabin and the sensor signal, the cancellation filter registered in association with the ID is read out, and an antiphase sound is generated and emitted, thereby achieving NC.

However, during NC processing, the cancellation filter itself may be inferred based on the noise in the vehicle cabin and the sensor signal, and an anti-phase sound may be generated by the inferred cancellation filter and emitted to achieve NC processing. In this case, the cancellation filter itself is used as training data in the machine learning during the filter generation process, and a trained model is generated that infers the cancellation filter itself based on the noise in the vehicle cabin and the sensor signal.

Furthermore, during NC processing and filter generation processing, as necessary, as described with reference to Figures 9 to 12, an exterior microphone 211 may be provided to pick up noise outside the vehicle cabin and remove the noise components outside the vehicle cabin from the noise inside the vehicle cabin.

Furthermore, in addition to the sensors 151-1 to 151-n, sensor signals based on the sensing results of on-board sensors including the external recognition sensor 25, the in-vehicle sensor 26, and the vehicle sensor 27 in the vehicle control system 11 may be used.

FIG. 19 shows an example of the configuration of the NC device 33 in which, during NC processing, the cancellation filter itself is inferred based on the noise picked up by the in-vehicle microphone 152 and the sensor signals that are the sensing results of the sensors 151-1 to 151-n, and the inferred cancellation filter generates and emits sound of an antiphase, thereby realizing NC processing.

FIG. 20 shows an example configuration of a filter generation processing unit 181' in which the cancellation filter itself is used as training data in machine learning during the filter generation process, and a trained model is generated that infers the cancellation filter itself based on the noise in the vehicle cabin and the sensor signal.

In addition, in the NC device 33 in FIG. 19 and the filter generation processing unit 181' in FIG. 20, components having the same functions as those in the NC device 33 in FIG. 15 and the filter generation processing unit 181' in FIG. 16 are given the same reference numerals, and descriptions thereof will be omitted as appropriate.

In other words, the NC device 33 in FIG. 19 differs from the NC device 33 in FIG. 15 in that the filter search unit 253 and the cancellation filter set storage unit 254 are deleted, and a DNN inference unit 251' is provided instead of the DNN inference unit 251.

In other words, since the DNN inference unit 251' infers the cancellation filter itself in the NC processing, it is only necessary to output the cancellation filter resulting from the inference to the NC signal calculation unit 255, and therefore the filter search unit 253 and cancellation filter set storage unit 254 are unnecessary and have been deleted.

The DNN inference unit 251' in FIG. 19 infers the cancellation filter by using the noise signal inside the vehicle cabin from the vehicle interior microphone 152 and the sensor signals of the sensors 151-1 to 151-n, as well as the noise outside the vehicle cabin from the vehicle exterior microphone 211 and the sensor signal consisting of the sensing result of the vehicle-mounted sensor 291. This makes it possible to improve the inference accuracy of the cancellation filter.

Furthermore, the filter generation processing unit 181' in FIG. 20 differs from the filter generation processing unit 181' in FIG. 16 in that the filter recording control unit 272 and the cancellation filter set storage unit 254 are deleted, and a cancellation filter design unit 271' and a DNN learning unit 273' are provided instead of the cancellation filter design unit 271 and the DNN learning unit 273, and further, the vehicle exterior sound determination unit 221 described with reference to FIG. 12 is provided.

In other words, in the filter generation process, the DNN learning unit 273' learns a learned model that infers the cancellation filter itself, and therefore uses the cancellation filter supplied by the cancellation filter design unit 271' as is as training data, so the filter search unit 253 and cancellation filter set storage unit 254 are unnecessary and have been deleted.

The DNN learning unit 273' in FIG. 20 learns a learning model that infers a cancellation filter using the noise outside the vehicle cabin from the exterior microphone 211, the noise at the control point from the control point proximity microphone 182, and the sensor signal consisting of the sensing result of the on-board sensor 291, in addition to the noise signal inside the vehicle cabin from the interior microphone 152 and the sensor signals of the sensors 151-1 to 151-n. This makes it possible to improve the inference accuracy of the cancellation filter using the learned model. Furthermore, by learning information such as road conditions and tire pressure in addition to the above-mentioned sensor signals and sounds related to noise, it becomes possible to infer a cancellation filter that has a higher noise reduction effect. Therefore, for example, the on-board sensor 291 may treat a series of information related to the driving environment, such as road surface images (road surface conditions) captured by the camera 51 of the external recognition sensor 25 described above, weather conditions, date and time information such as day or night, and tire air pressure detected by the vehicle sensor 27, as information related to noise and use it to learn a learning model that infers a cancellation filter.

Furthermore, when the noise outside the vehicle cabin is greater than a predetermined level as determined by the vehicle exterior sound determination unit 221, it becomes difficult for the cancellation filter design unit 191 to design an appropriate cancellation filter, so the cancellation filter design unit 271' in FIG. 20 stops designing. At this time, the DNN learning unit 273 stops learning because a cancellation filter is not supplied as training data. In this way, when generating a learning model that infers the cancellation filter itself, it is possible to learn by excluding inappropriate training data, thereby improving the inference accuracy of the cancellation filter.

The filter generation process by the filter generation processing unit 181' in FIG. 20 is basically the same as the filter generation process described with reference to the flowchart in FIG. 17, except that in addition to the noise signal from the in-vehicle microphone 152 and the sensor signals from the sensors 151-1 to 151-n, the signal from the exterior microphone 211 and the sensor signal from the in-vehicle sensor 291 are added as student data, and the teacher data becomes the cancellation filter itself, so a description of this process will be omitted.

In addition, in the NC processing unit 153' in FIG. 19, the DNN inference unit 251' surrounded by a dotted line can be said to independently realize the function of providing a cancellation filter at the control point to the NC signal calculation unit 175 based on the sensor signals of the sensors 151-1 to 151-n and the input signal of the sound as noise picked up by the in-vehicle microphone 152.

Furthermore, with regard to the NC processing by the NC device 33 in FIG. 19, in addition to the noise signal from the in-vehicle microphone 152 and the sensor signals from the sensors 151-1 to 151-n, the signal from the exterior microphone 211 and the sensor signal from the in-vehicle sensor 291 are added, the determination result from the exterior sound determination unit 221 is supplied to the cancellation filter design unit 271', and the cancellation filter itself is inferred. Except for this, the basic processing is the same as the NC processing described with reference to the flowchart in FIG. 18, so a description thereof will be omitted.

Furthermore, with regard to the trained model stored in the trained model storage unit 252 and trained model storage unit 252' in FIG. 15, and the cancellation filter set stored in the cancellation filter set storage unit 254 in FIG. 15, it is assumed that the NC unit 33 in FIG. 15 and FIG. 19 will be mounted as the NC unit 33 of the vehicle control system 11 in a vehicle 1, such as a commercially available passenger car.

For this reason, once NC devices 33 are released on the market with trained models and cancellation filter sets installed, over time the conditions at the time of learning will change due to aging of the tires and changes in the road surface, and the trained models and cancellation filter sets originally installed may gradually become unable to provide sufficient noise reduction effects.

In such a case, a separate filter generation process may be performed by another filter generation processing unit 181' under new conditions of tires and road surfaces that were not learned, to generate a learned model and cancellation filter set that conform to the new conditions (based on the sound picked up by the in-vehicle microphone 152 under the new conditions, the sound picked up by the control point microphone 182, and the sensor signal of the sensor 151, or based on the relationship therewith).

In other words, by distributing the trained model and cancellation filter set generated under new conditions to the NC device 33 via a cloud server or the like, it becomes possible to update the trained model and cancellation filter set, so that a sufficient noise reduction effect can be obtained even if the conditions change due to aging.

<<7. Second embodiment>>
<Feedback type NC device>
The FF type NC device has been described above. Next, a feedback type NC device will be described as a configuration example of a second embodiment of the NC device 33 of the present disclosure.

More specifically, as shown in Figures 21 and 22, the feedback type NC device 33 is composed of sensors 311-1 to 311-8, actuators 312-1 to 312-8, and an NC processing unit 313. Note that Figure 21 is a side cross-sectional view of a vehicle 1 provided with two pairs of sensors 311 and actuators 312, and Figure 22 is a front view of the front window (glass) FW of the vehicle 1 as viewed from the front of the vehicle 1.

Sensors 311-1 to 311-8 and actuators 312-1 to 312-8 are attached to the edge of the windshield FW with adhesive or the like so as not to obstruct the view of the driver/user.

Sensors 311-1 to 311-8 are acceleration sensors that detect vibrations of the front window FW at positions near the corresponding positions, and output sensor signals representing the sensing results to the NC processing unit 313.

Actuators 312-1 to 312-8 are attached to positions corresponding to sensors 311-1 to 311-8, respectively, and are controlled by the NC processing unit 313 to vibrate the corresponding front window FW.

When the NC processing unit 313 receives a sensor signal consisting of acceleration information corresponding to vibrations in the front windshield FW supplied from the sensors 311-1 to 311-8, it controls the actuators 312-1 to 312-8 in the corresponding positions to vibrate the front windshield FW in the corresponding locations so as to cancel out the vibrations detected by the sensors 311-1 to 311-8.

The feedback type NC device 33, with this configuration, detects vibrations of objects that generate noise, such as panels like the front window FW, and applies a specified NC filter process to the vibration detection results, thereby reducing noise by suppressing the vibration of the object by applying an excitation of the opposite phase to the detected vibration.

Unlike NC processing such as the feedforward NC device 33, which assumes that the vibration source that generates the noise, such as tires, is known, the feedback NC device 33 can reduce noise even when the vibration source is unknown by forcibly suppressing the vibration of objects such as panels that are already generating noise by using actuators, etc.

<Example of actuator configuration>
23 is a side cross-sectional view of the actuator 312 attached to the front window FW. The sensor 311 on the right side of the figure is paired with the actuator 312.

The actuator 312 is composed of an actuator base 321, a voice coil case 322, a voice coil 323, a damper 324, and a voice coil bobbin 325.

The actuator base 321 supports the entire actuator 312, and its bottom is attached to the front window FW with adhesive or the like.

The voice coil case 322 is a case that covers the entire outer periphery of the voice coil 323 and is integral with the voice coil 323.

The voice coil 323 is electrically connected to the NC processing unit 313 by electrical wiring (not shown), and is excited by a drive signal applied from the NC processing unit 313, vibrating in the direction of the arrow in the figure at a frequency according to the frequency of the drive signal, causing the voice coil case 322, which is integral with the voice coil 323, to vibrate in the direction of the arrow in the figure.

The damper 324 is a concentric bellows that connects, with a predetermined tension, the outer circumferential side of the cylindrical bobbin 325 with an opening in the vertical direction in the figure, and the inner circumferential side of the voice coil case 322. By connecting the outer circumferential side of the bobbin 325 and the inner circumferential side of the voice coil case 322 with a predetermined tension, the damper 324 fixes the voice coil case 322 in a stationary position where the damper 324 is maintained in a substantially horizontal direction, as shown in FIG. 23, when no drive signal is supplied to the voice coil 323. When a drive signal is supplied to the voice coil 323, the bellows-shaped damper 324 expands and contracts to limit the range of motion of the voice coil case 322, which vibrates in the vertical direction.

The bobbin 325 is cylindrical and functions as the central axis of the actuator 312. The axis 322a of the voice coil case 322 is inserted into the opening at the top in the figure in a state in which it can slide up and down in the figure. The protrusion 321a of the actuator base 321 is inserted into the opening at the bottom of the bobbin 325 in a fixed state.

With this configuration, when a drive signal of a predetermined voltage and a predetermined frequency is supplied from the NC processing unit 313, the voice coil 323 vibrates in the vertical direction as indicated by the arrow in the figure, and the shaft 322a of the voice coil case 322, which is configured as one piece with the voice coil 323, vibrates by sliding up and down within the bobbin 325 according to the tension of the damper 324.

When the voice coil case 322 vibrates in this manner, a force corresponding to the weight of the voice coil case 322 including the voice coil 323 is applied to the front window FW via the actuator base 321, causing the front window FW to vibrate.

The NC processing unit 313 performs filtering on the acceleration signal detected by the sensor 311 to achieve a predetermined NC, and adjusts and supplies the drive signal to be applied to the voice coil 323, causing it to vibrate so as to cancel out the vibration of the front window FW detected by the sensor 311.

As a result, the vibrations that generate noise in the front window FW are countered by the actuator 312, suppressing the vibrations of the front window FW and making it possible to reduce the noise caused by the vibrations.

<Example of NC processing section configuration>
24, an example of the configuration of the NC processing unit 313 will be described. The NC processing unit 313 includes an amplifier 331, an NC filter processing unit 332, and an amplifier 333.

The amplifier 331 amplifies the detected acceleration signal supplied by the sensor 311 to a predetermined level and outputs it to the NC filter processing unit 332.

The NC filter processing unit 332 applies a predetermined NC filter process to the sensor signal corresponding to the acceleration detected by the sensor 311, which is supplied via the amplifier 331, to generate a drive signal that vibrates at a phase and frequency that cancels out the vibration of the front window FW, and the signal is amplified at a predetermined rate via the amplifier 333 and applied to the actuator 312 (its voice coil 323).

As a result, a drive signal corresponding to the acceleration detected on the front window FW is applied to the voice coil 323 of the actuator 312 so as to cancel out the vibrations, and the actuator 312 vibrates the front window FW in the vertical direction so as to cancel out the vibrations.

As a result, when the actuator 312 vibrates, the front window FW is vibrated with a force corresponding to the weight of the actuator 312, and the vibration of the front window FW detected by the sensor 311 is cancelled out, the vibration of the front window FW is suppressed, and the noise caused by the vibration of the front window FW is reduced.

<NC processing using sensors and actuators>
Next, the NC processing by the sensor 311 and the actuator 312 in FIGS. 23 and 24 will be described with reference to the flow chart in FIG.

In step S201, the NC filter processing unit 332 of the NC processing unit 313 acquires the sensor signal of the acceleration detected by the sensor 311 via the amplifier 331.

In step S202, the NC processing unit 313 performs NC filtering on the sensor signal provided by the sensor 311 to set a drive signal that vibrates the voice coil 323.

In step S203, the NC processing unit 313 applies the drive signal set by the filter processing, which vibrates the voice coil 323, to the actuator 312 via the amplifier 333, causing the actuator 312 to vibrate so as to cancel out the vibration of the front window FW.

In step S204, it is determined whether or not an instruction to end has been given. If an instruction to end has not been given, the process returns to step S201, and the subsequent steps are repeated. Then, if an instruction to end has been given in step S204, the process ends.

By performing the above process, the actuator 312 vibrates, which causes the front window FW to vibrate, suppressing the vibration and reducing noise caused by the vibration of the front window FW.

<<8. First Modification of the Second Embodiment>>
The FB type NC unit 33 has been described above. When the actuators 312 in FIG. 23 are used and eight of each type are installed in pairs with the same number of sensors 311 as shown in FIG. 22, a total of 16 parts need to be attached along the outer periphery of the front windshield FW, which means a large number of installation steps.

Therefore, it is conceivable that by integrating the actuator and sensor into a structure, it would be possible to reduce the amount of work required for installation.

FIG. 26 is a side cross-sectional view of an actuator that integrates an actuator and a sensor. The actuator 312A in FIG. 26 is composed of an actuator base 361, a voice coil case 362, a voice coil 363, a damper 364, a voice coil bobbin 365, and a sensor 311'.

The actuator base 361, the voice coil case 362, the voice coil 363, the damper 364, and the voice coil bobbin 365 correspond to the actuator base 321, the voice coil case 322, the voice coil 323, the damper 324, and the voice coil bobbin 325 in FIG. 23, respectively. The sensor 311' has the same configuration as the sensor 311 in FIG. 23.

By configuring it in this way, when installing it on the front windshield FW, the actuator 312A is structured to include the sensor 311', so it is possible to attach both at the same time, halving the labor required for installation.

Note that the NC processing by actuator 312A in FIG. 26 is omitted because the processing by sensor 311' is similar to the processing by sensor 311, and the processing by actuator 312A is similar to the processing by actuator 312. Note that the same replacement is used in the subsequent processing, so the explanation is also omitted.

<<9. Second Modification of Second Embodiment>>
In the above, we have described a configuration in which the actuator and sensor are integrated. However, when the actuator and sensor are integrated, for example, if a malfunction occurs in voice coil 363, which is the driving part, and it becomes necessary to replace it, it will also be necessary to replace sensor 311', and since even sensor 311' that is not malfunctioning will have to be replaced, the repair costs will be high.

Therefore, the voice coil case 362 and the actuator base 361 may be configured to be detachable, so that if a malfunction occurs in the voice coil 363, only the voice coil case 362 can be replaced.

FIG. 27 is a side cross-sectional view of actuator 312B, in which voice coil case 362 and actuator base 361 can be detached. Note that in actuator 312B in FIG. 26, components having the same functions as actuator 312A in FIG. 25 are given the same reference numerals, and their description will be omitted.

The actuator 312B in FIG. 27 differs from the actuator 312A in FIG. 26 in that it can be disassembled into a drive unit 312Ba consisting of a voice coil case 362 and a base unit 312Bb consisting of an actuator base 361.

Also, in the actuator 312B of FIG. 27, a bobbin 373 is provided instead of the bobbin 365. A hole is formed in the shaft 362a of the voice coil case 362, as shown by the arrow, into which the bolt 372 can be inserted, and the bolt passes through the hole to reach the bobbin 373. A base plate 371 is provided at the bottom of the bobbin 373, with a hole 371a provided therein into which the threaded portion 372a of the bolt 372 can be inserted from the top in the figure. The actuator base 361B is provided with a convex portion 361Ba at the center of the top, with a screw hole 361Bb into which the threaded portion 372a of the bolt 372 can be screwed from the top in the figure.

With this configuration, the bolt 372 passes through the hole 371a of the base plate 371 provided at the bottom of the bobbin 373 and is screwed into the screw hole 361Bb provided at the top of the convex portion 361a' of the actuator base 361, joining the base plate 371 and the top of the convex portion 361a', and joining and integrating the drive portion 312Ba and the base portion 312Bb consisting of the actuator base 361 to form the actuator 312B.

Conversely, when the threaded portion 372a of the bolt 372 is pulled out from the hole 371a of the base plate 371 provided at the bottom of the bobbin 373 and the threaded hole 361Bb provided at the top of the convex portion 361Ba of the actuator base 361B, the connection between the base plate 371 and the top of the convex portion 361Ba is released, and the drive portion 312Ba and the base portion 312Bb become disassembled.

With this configuration, when installing the actuator 312B on the front windshield FW, as shown in FIG. 28, the bolt 372 passes through the hole 371a of the base plate 371 and is screwed into the screw hole 361Bb provided at the top of the protrusion 361Ba of the actuator base 361B, and the drive unit 312Ba and base unit 312Bb are joined together, allowing the work to proceed in this integrated state.

By doing this, it becomes possible to install the actuator 312B including the sensor 311', which makes it possible to reduce the amount of work required for installation.

Also, if the voice coil 363 malfunctions and needs to be replaced, as shown in FIG. 29, the screw portion 372a of the bolt 372 is removed from the screw hole 361Bb provided at the top of the convex portion 361Ba, and only the drive portion 312Ba is removed from the base portion 312Bb and replaced.

In this case, since the base part 312Bb remains attached to the front window FW, replacement is possible simply by connecting a new drive part 312Ba to the base part 312Bb using the bolts 372, eliminating the need for repositioning. Also, if there is no abnormality in the sensor 311', the one that was previously in use can be reused as is, making it possible to reduce the cost and effort involved in replacement.

<<10. Third Modification of Second Embodiment>>
In the above, we have described the actuator 312B in which one sensor 311' for detecting acceleration related to the vibration of the front window FW is provided on the actuator base 361, but it is also possible to provide a sensor on the voice coil case 362 to detect acceleration related to the vibration of the voice coil case 362.

Figure 30 shows a side cross-sectional view of actuator 312C in which a sensor is provided on voice coil case 362 to detect acceleration related to vibration of voice coil case 362.

Actuator 312C in FIG. 30 differs from actuator 312B in FIG. 27 in that a sensor 311'' is newly provided on voice coil case 362 to detect acceleration related to vibration of voice coil case 362.

The sensor 311'' detects the acceleration related to the vibration of the voice coil case 362 and outputs it to the NC processing unit 313.

With this configuration, the acceleration related to the vibration of the voice coil case 362 is detected, making it possible to recognize the state of vibration applied to the front windshield FW and set the drive signal for the actuator 312C based on this, making it possible to more appropriately suppress the vibration of the front windshield FW and more appropriately reduce the noise caused by the vibration. In addition, because abnormal vibrations in the voice coil case 362 can be detected based on the acceleration related to the vibration of the voice coil case 362, it becomes possible to detect abnormalities occurring in the voice coil 363.

<<11. Fourth Modification of the Second Embodiment>>
In the above, a configuration has been described that assumes that separate connection work is required for wiring to the voice coil 363, but it is also possible to form a wiring connection portion on a part of the abutting base plate 371 and the top of the convex portion 361a', and to connect the wiring simply by joining the drive portion 312Ba and the base portion 312Bb.

Figure 31 shows a side cross-sectional view of actuator 312D, which has wiring connection sections formed on part of base plate 371 and the top of protrusion 361a', allowing wiring to be connected simply by joining drive section 312Da and base section 312Db.

Actuator 312D in FIG. 31 differs from actuator 312B in FIG. 27 in that wiring connection portion 382a is formed in part of the bottom of base plate 371 in the figure, and wiring connection portion 382b is formed in part of the top of protrusion 361Da.

The wiring connection parts 382a, 382b are formed in positions facing each other when the drive part 312Da and the base part 312Db are joined by the bolt 372.

The wiring connection portion 382b is also connected to a connector 381 formed on the actuator base 361. When the wiring (not shown) to the NC processing portion 313 is connected to the connector 381, the NC processing portion 313 can supply a drive signal to the voice coil 363.

With this configuration, the electrical connection between the voice coil 363 and the NC processing unit 313 can be completed simply by joining the drive unit 312Da and the base unit 312Db with the bolts 372, making it possible to reduce the labor required for wiring connections when replacing the drive unit 312Da.

<<12. Fifth Modification of the Second Embodiment>>
The above describes an example in which the physical connection and electrical connection between the drive unit 312Da and the base unit 312Db can be achieved simultaneously by simply using the bolt 372, but it is also possible to form a screw thread on the outer periphery of the convex portion 361Da of the actuator base 361D so that the two can be connected by a connector.

This is a side cross-sectional view of actuator 312E, which has a screw thread formed on the outer periphery of protrusion 361a of actuator base 361, allowing connection with a connector.

The actuator 312E in FIG. 32 differs from the actuator 312B in FIG. 27 in that a screw thread is formed on the outer periphery of the protrusion 361Ea of the actuator base 361E, and the actuator is connected by a cylindrical connector 391 that has a screw thread formed on the inside.

The connector 391 is cylindrical and has approximately the same diameter as the convex portion 361Ea and the lower portion 371Eb of the base plate 371E, with a screw thread 391a formed on its inner circumference, and a lid 391b with an opening only at the upper portion in the figure. The opening of the lid 391b has a smaller diameter than the convex portion 361Ea and the lower portion 371Eb of the base plate 371E, and is approximately the same diameter as the bobbin 373, through which the bobbin 373 is inserted. Furthermore, the upper portion 371Ea of the base plate 371E has the same diameter as the bobbin 373, and the lower portion 371Eb is larger in diameter than the bobbin 373 and approximately the same diameter as the convex portion 361Ea, and is connected to the lower end of the bobbin 373 in the figure with an adhesive or the like.

As a result, the screw threads 391a of the connector 391 and the screw threads formed on the outer periphery of the protrusion 361Ea are screwed together, so that the base plate 371E and the top of the protrusion 361Ea are connected in abutting contact with each other. In addition, the screwed connection between the connector 391 and the protrusion 361Ea is released, so that the drive unit 312Ea and the base unit 312Eb can be separated.

This configuration makes it possible to attach and detach the drive unit 312Ea and the base unit 312Eb.

<<13. Sixth Modification of the Second Embodiment>>
In the above, an example has been described in which a screw thread is formed on the outer periphery of the protrusion 361Ca of the actuator base 361C so as to enable connection using the connector 391, but the bolt 372 and the base plate 371 may also be integrated into one structure.

Figure 33 is a side cross-sectional view of actuator 312F, in which bolt 372 and base plate 371 are integrated.

In the actuator 312F in FIG. 33, a bolt portion 371Fa is formed on the base plate 371F at the downward direction in the figure, and by fitting into a hole portion 361Fb formed at the top of the protrusion 361Fa of the actuator base 361F, the base plate 371D and the protrusion 361Da are joined, making it possible to connect the drive portion 312Fa and the base portion 312Fb.

<<14. Seventh Modification of the Second Embodiment>>
In the above, an example has been described in which the bolt 372 and the base plate 371 are integrated into one structure. However, it is also possible to use a structure in which no threads are provided on the inside of the connector 391 in FIG. 32, and the top of the convex portion 361a of the actuator base 361 is fitted in a cap-like shape and then screwed in place separately.

Figure 34 is a side cross-sectional view of an actuator 312G that has a connector that fits into the protrusion 361Ga of the actuator base 361G in a cap-like shape, and that can connect the drive unit 312Ga and base unit 312Gb by screwing the connector and the protrusion 361Ga together.

In the actuator 312G in FIG. 34, the drive unit 312Ga and base unit 312Gb are connected by a connector 401 that fits and fixes the protrusion 361Ga of the actuator base 361G in a cap-like shape.

The connector 401 has an opening in the upper portion 401a that is smaller in diameter than the protrusion 361Ga and the lower portion 371Gb of the base plate 371G, and has approximately the same diameter as the bobbin 373.

The upper portion 371Ga of the base plate 371G has a diameter slightly smaller than that of the bobbin 373, and the lower portion 371Gb has a diameter larger than that of the bobbin 373 and is approximately the same diameter as the protruding portion 361Ga.

The connector 401 is configured like a cap that fits over the entire head of the convex portion 361Ga when the base plate 371G is placed on the top of the convex portion 361Ga.

The convex portion 361Ga has screw holes 361Gb-1 and 361Gb-2 formed on the side, and screws 402-1 and 402-2 are inserted through the side of the connector 401, which is cap-shaped and covers the top of the convex portion 361Ga, and screwed into the screw holes 361Gb-1 and 361Gb-2 of the convex portion 361Ga, so that the connector 401 and the convex portion 361Ga are fixed in a connected state.

In this way, the connector 401 is connected and fixed to the top of the protrusion 361Ga of the actuator base 361G, making it possible to connect the drive unit 312Ga to the base unit 312Gb.

Furthermore, when the screws 402-1 and 402-2 are removed from the screw holes 361Gb-1 and 361Gb-2, the connection between the connector 401 and the protrusion 361Ga is released, and the connection between the drive unit 312Ga and the base unit 312Gb is also released, making it possible to separate the two.

The actuators 312, 312A to 312G described in the second embodiment have different structures, but the operation and processing in the NC processing described with reference to the flowchart in FIG. 25, for example, are all the same. Therefore, in the following, when describing the processing, actuator 312 will be used as a representative explanation as necessary, but the actuator will function in the same way even if actuator 312 is replaced with any of actuators 312A to 312G.

<<15. Eighth Modification of Second Embodiment>>
In the above, an example has been described in which the NC processing unit 313 generates a drive signal by performing NC filtering on the sensor signal, which is the sensing result from the sensor 311, and supplies the drive signal to the actuator 312 to operate it.

However, it is known that the frequency characteristics of the vibration force of actuator 312 depend on the ambient temperature.

More specifically, since the compliance of the damper 364 depends on the temperature, for example, the vibration force for each frequency has a larger compliance at high temperatures and a smaller compliance at low temperatures, as shown in FIG. 35.

In FIG. 35, waveform Fh shows the compliance characteristics of damper 364 at high temperatures, and waveform Fc shows the compliance characteristics of damper 364 at low temperatures.

As a result, NC filter processing is tailored to the compliance characteristics at a specific ambient temperature, so if the ambient temperature changes and the actuator characteristics change, the original NC performance may not be achieved.

In view of this, the ambient temperature of the actuator 312 may be estimated using an exterior temperature sensor and an interior temperature sensor that are generally mounted on the vehicle 1, and the NC filter may be switched depending on the estimated ambient temperature of the actuator 312. In addition, if the ambient temperature of the actuator 312 exceeds a range in which it can be safely used, the output of the amplifier to the actuator 312 may be muted to protect the actuator 312.

FIG. 36 shows an example of the configuration of an NC processing unit 313' that switches the NC filter depending on the ambient temperature of the actuator 312 and mutes the amplifier output to the actuator 312 if the ambient temperature of the actuator 312 exceeds the range in which it can be safely used.

The NC processing unit 313' in FIG. 36 includes an amplifier 331, NC filter processing units 332c and 332h, an amplifier 333, switches 421 and 422, and an operation control unit 423.

Furthermore, amplifier 331, NC filter processing units 332c and 332h, and amplifier 333 are basically configured to have the same functions as amplifier 331, NC filter processing unit 332, and amplifier 333 in FIG. 24, respectively.

However, while the NC filter processing unit 332 performs filtering according to the compliance characteristics of the damper 364 when the ambient temperature is a predetermined value, the NC filter processing unit 332c performs filtering for low temperatures according to the compliance characteristics of the damper 364 when the ambient temperature is lower than a predetermined threshold, and the NC filter processing unit 332h performs filtering for high temperatures according to the compliance characteristics of the damper 364 when the ambient temperature is higher than a predetermined threshold.

The operation control unit 423 estimates the ambient temperature of the actuator 312 from the temperature outside the vehicle cabin and the temperature inside the vehicle cabin, which are supplied by an outside vehicle cabin temperature sensor 431 and an inside vehicle cabin temperature sensor 432, respectively, which are mounted on a typical vehicle 1.

When the ambient temperature of the actuator 312 is lower than a predetermined threshold, the operation control unit 423 connects the switch 421 to the terminal 421c so that the sensor signal from the amplifier 331 is supplied to the NC filter processing unit 332c, and switches to an operation mode in which NC filter processing is performed with characteristics lower than the predetermined temperature.

When the ambient temperature of the actuator 312 is higher than a predetermined threshold, the operation control unit 423 connects the switch 421 to the terminal 421h so that the sensor signal from the amplifier 331 is supplied to the NC filter processing unit 332h, and switches to an operation mode in which NC filter processing is performed with characteristics higher than the predetermined temperature.

If the ambient temperature of the actuator 312 is not within the range in which the actuator can safely operate, the operation control unit 423 connects the switch 422 to the terminal 422b, and opens the output from the amplifier 333 to ground, switching to an operation mode in which the actuator 312 is essentially muted.

When the ambient temperature of the actuator 312 is within the range in which the actuator can safely operate, the operation control unit 423 connects the switch 422 to the terminal 422a, outputs the output from the amplifier 333 to the actuator 312, and switches to a mode in which normal NC processing is performed.

With this configuration, the NC processing unit 313' in FIG. 36 appropriately switches between the NC filter processing units 332c and 332h in accordance with the temperature characteristics based on the ambient temperature of the actuator 312, making it possible to achieve appropriate NC processing. Furthermore, if the ambient temperature of the actuator 312 is not within a range in which the actuator 312 can safely operate, the output from the amplifier 333 is stopped, essentially muting the output, thereby protecting the actuator 312.

<Operation mode control process by the NC processing unit in FIG. 36>
Next, the operation mode control process by the NC processing unit 313' in FIG. 36 will be described with reference to the flowchart in FIG.

In step S231, the operation control unit 423 estimates the ambient temperature of the actuator 312 from the temperature outside the vehicle cabin and the temperature inside the vehicle cabin, which are supplied by the outside vehicle cabin temperature sensor 431 and the inside vehicle cabin temperature sensor 432, respectively.

In step S232, the operation control unit 423 determines whether the estimated ambient temperature of the actuator 312 is within a temperature range in which the actuator 312 can operate safely.

If it is determined in step S232 that the estimated ambient temperature of the actuator 312 is within a temperature range in which the actuator 312 can operate safely, processing proceeds to step S233.

In step S233, the operation control unit 423 sets the operation mode to ON, connects the switch 422 to the terminal 422a, and makes it possible for the drive signal output from the amplifier 333 to be supplied to the actuator 312.

In step S234, the operation control unit 423 determines whether the estimated ambient temperature of the actuator 312 is equal to or lower than the upper limit temperature that can be used with the low-temperature NC filter.

If it is determined in step S234 that the estimated ambient temperature of the actuator 312 is equal to or lower than the upper limit temperature that can be used with the low-temperature NC filter, processing proceeds to step S235.

In step S235, the operation control unit 423 sets the operation mode to the low temperature NC filter and connects the switch 421 to the terminal 421c so that the sensor signal from the amplifier 331 is supplied to the NC filter processing unit 332c.

On the other hand, if it is determined in step S234 that the estimated ambient temperature of the actuator 312 is not equal to or lower than the upper limit temperature that can be used with the low-temperature NC filter, processing proceeds to step S236.

In step S236, the operation control unit 423 sets the operation mode to a high-temperature NC filter mode and connects the switch 421 to the terminal 421h so that the sensor signal from the amplifier 331 is supplied to the NC filter processing unit 332h.

If it is determined in step S232 that the estimated ambient temperature of the actuator 312 is not within the temperature range in which the actuator 312 can safely operate, the process proceeds to step S237.

In step S237, the operation control unit 423 sets the operation mode to OFF, connects the switch 422 to terminal 422b, and sets the output from the amplifier 333 to not be output to the actuator 312, essentially muting the operation mode.

In step S238, the operation control unit 423 determines whether or not an instruction to end the operation has been given. If an instruction to end the operation has not been given, the process returns to step S231, and the subsequent processes are repeated.

Then, in step S238, if an instruction to end is given, the process ends.

The above process allows the NC filter processing units 332c and 332h to be appropriately switched and used according to the temperature characteristics based on the ambient temperature of the actuator 312, making it possible to achieve appropriate NC processing. Furthermore, if the ambient temperature of the actuator 312 exceeds the range in which the actuator 312 can safely operate, the output of the drive signal from the amplifier 333 is stopped, essentially muting the actuator 312, making it possible to protect the actuator 312.

In addition, the NC processing thereafter is substantially the same as that described with reference to the flowchart in FIG. 25, based on the settings made in the operation mode control processing described with reference to the flowchart in FIG. 37. However, the filter processing is switched between low and high temperature based on the ambient temperature of the actuator 312, and when it is outside the range in which it can operate safely, the output to the actuator 312 is stopped for protection.

For example, if the lower limit temperature of the low-temperature NC filter is 0 degrees and the upper limit temperature is less than 20 degrees, the lower limit temperature of the high-temperature NC filter is 20 degrees or higher and the upper limit temperature is less than 40 degrees, and the safe operating temperature range is up to 40 degrees, then when the ambient temperature of the actuator 312 is between 0 and 20 degrees, low-temperature NC filter processing is performed, when it is between 20 and 40 degrees, high-temperature NC filter processing is performed, and when it is less than 0 degrees or more than 40 degrees, it is muted.

<<16. Ninth Modification of the Second Embodiment>>
In the above, an example has been described in which the ambient temperature of the actuator is estimated using a general interior temperature sensor and an exterior temperature sensor, and the NC filter is switched based on the estimation result, and the supply of a control signal to the actuator 312 is stopped when the temperature is within a range in which safe operation is not possible.

However, there are cases where a signal from a temperature sensor cannot always be obtained, and in such cases the above-mentioned processing cannot be realized. However, since many vehicles 1 nowadays are equipped with navigation devices, if the ambient temperature can be estimated using a sensor signal from a sensor that is always provided in the navigation device, the above-mentioned processing can be realized. In addition, the compliance characteristics of the damper 364 change significantly even with a small change in temperature, and it is desirable to be able to switch to more NC filters for each fine temperature range based on the ambient temperature.

FIG. 38 shows an example configuration of an NC processing unit 313'' that estimates the ambient temperature using a sensor that is always provided in navigation devices installed in many vehicles 1, and can switch to NC filter processing that corresponds to a wider range of temperature characteristics based on the estimation result.

The NC processing unit 313'' includes an amplifier 331, NC filter processing units 332-1 to 332-n, an amplifier 333, a switching unit 421', a switch 422, an operation control unit 423', and a sun direction calculation unit 441.

Note that the amplifier 331, the NC filter processing units 332-1 to 332-n, and the amplifier 333 have the same functions as the amplifier 331, the NC filter processing unit 332, and the amplifier 333 in FIG. 24, respectively.

However, the NC filter processing units 332-1 to 332-n perform filter processing according to the compliance characteristics of the damper 364, which are set for each fine range of the ambient temperature of the actuator 312.

The switching unit 421' has a configuration corresponding to the switch 421 in FIG. 36, and is controlled by the operation control unit 423' to be connected to the NC filter processing unit 332 that corresponds to the estimated ambient temperature of the actuator 312. The switch 422 has the same configuration as that in FIG. 36.

The sun direction calculation unit 441 obtains direction information from a compass 451, which is a sensor typically installed in navigation devices, obtains position information from a GPS 452, and obtains date and time information 453 based on the time information obtained by the GPS 452, thereby calculating the sun direction at the current position and outputting the result to the operation control unit 423'.

The operation control unit 423' has the same basic functions as the operation control unit 423, but instead of temperature information from the exterior temperature sensor 431 and the interior temperature sensor 432, it acquires information on the direction of the sun supplied from the sun direction calculation unit 441. The operation control unit 423 estimates the ambient temperature of the actuator 312 by estimating the irradiation conditions of direct sunlight based on the information on the direction of the sun supplied from the sun direction calculation unit 441.

By not using a temperature sensor in this way, it is possible to accommodate vehicles 1 that are not equipped with a temperature sensor, and it is also possible to reduce the cost of installing wiring.

The operation control unit 423' selects an NC filter processing unit 332 in a usable temperature range based on the estimated ambient temperature of the actuator 312, applies NC filter processing to the acceleration sensor signal from the amplifier 331, and generates a drive signal for driving the actuator 312, which is output via the amplifier 333.

<Operation mode control process by the NC processing unit in FIG. 38>
Next, the operation mode control process by the NC processing unit 313'' in FIG. 38 will be described with reference to the flowchart in FIG.

In step S251, the sun direction calculation unit 441 acquires direction information from the compass 451, acquires position information from the GPS 452, acquires date and time information 453 based on the time information acquired by the GPS 452, calculates the sun direction at the current position from this information, and outputs it to the operation control unit 423'.

In step S252, the operation control unit 423' estimates the direct sunlight irradiation conditions based on the solar direction provided by the solar direction calculation unit 441, and estimates the ambient temperature of the actuator 312 from the estimation result.

In step S253, the operation control unit 423' determines whether the estimated ambient temperature of the actuator 312 is within a temperature range in which the actuator 312 can operate safely.

If it is determined in step S253 that the estimated ambient temperature of the actuator 312 is within a temperature range in which the actuator 312 can safely operate, processing proceeds to step S254.

In step S254, the operation control unit 423' sets the operation mode to ON, connects the switch 422 to the terminal 422a, and makes it possible for the drive signal output via the amplifier 333 to be output to the actuator 312.

In step S255, the operation control unit 423' sets the NC filter processing mode by the NC filter processing unit 332 that corresponds to the estimated ambient temperature of the actuator 312, among the NC filter processing units 332-1 to 322-n, and supplies the sensor signal from the amplifier 331.

If it is determined in step S253 that the estimated ambient temperature of the actuator 312 is not within the temperature range in which the actuator 312 can safely operate, the process proceeds to step S256.

In step S256, the operation control unit 423' sets the operation mode to OFF, connects the switch 422 to the terminal 422b, and sets the output from the amplifier 333 to be not output to the actuator 312, essentially muting the operation mode.

In step S257, the operation control unit 423' determines whether or not an instruction to end the operation has been given. If an instruction to end the operation has not been given, the process returns to step S251, and the subsequent processes are repeated.

Then, in step S257, if an instruction to end is given, the process ends.

By the above process, NC filter processing units 332-1 to 332-n perform NC filter processing with temperature characteristics corresponding to the estimated ambient temperature based on the ambient temperature of actuator 312, making it possible to realize appropriate NC processing. Furthermore, if the ambient temperature of actuator 312 exceeds the range in which actuator 312 can safely operate, output from amplifier 333 is stopped, essentially muting the output, making it possible to protect actuator 312.

<<17. Tenth Modification of the Second Embodiment>>
In the above, an example has been described in which the ambient temperature of the actuator is estimated, the NC filter is switched based on the estimation result, and the supply of a control signal to the actuator 312 is stopped when the temperature is within a range in which safe operation is not possible.

However, it is also possible to upload information about the actuator 312 to the cloud in association with various types of information such as position information and driving information, and to switch the NC filter processing unit 332 based on that information.

Figure 40 shows an example configuration of an NC processing unit 313''' in which actuator 312 information is uploaded to the cloud in association with position information and various other information, and the NC filter processing unit 332 is switched based on that information.

The NC processing unit 313'' in FIG. 40 differs from the NC processing unit 313'' in FIG. 38 in that the sun direction calculation unit 441 has been deleted, and the operation control unit 423'' has been replaced with an operation control unit 423'', and a current sensor 462 has been provided between the switch 422 and the actuator.

The operation control unit 423'' has the same basic functions as the operation control unit 423', but rather than controlling the changeover unit 421' and the switch 422 based on the ambient temperature of the actuator 312, it controls them based on the signal from the sensor 311, position information, road conditions, time and date information, the vehicle's traveling speed, the NC filter coefficient, traffic information (traffic jams and occurrence of traffic accidents), road surface unevenness information from the LiDAR 461 (or camera), the drive signal for the actuator 312, and abnormality detection information for the actuator.

For example, the operation control unit 423'' accesses the cloud server 472 via an information terminal 471 such as a smartphone using a short-range communication means such as Bluetooth (registered trademark).

In the cloud server 472, information on the NC filter processing unit 332 and NC filter coefficients that are optimal for reducing noise identified from information such as the sensor 311 signal, location information, road conditions, time and date information, vehicle travel speed, and traffic information (occurrence of traffic jams and traffic accidents) is registered. This is information on the NC filter processing unit 332 that is optimal for reducing identified noise based on information identifying noise uploaded from other vehicles 1 in association with location information.

The operation control unit 423'' may access the cloud server 472 via the information terminal 471, and select the most suitable information for the NC filter processing unit 332 based on conditions such as the signal from its own sensor 311, location information, road conditions, time and date information, the vehicle's traveling speed, and traffic information (occurrence of traffic jams and traffic accidents), and control and switch the switching unit 421' to use the corresponding NC filter processing unit 332.

In addition, if the optimal NC filter processing unit 332 is not provided, the operation control unit 423'' may download the NC filter coefficients required to realize the optimal NC filter processing unit 332 from the cloud server 472 and update the NC filter coefficients in the NC filter processing units 332-1 to 322-n that it owns.

The operation control unit 423'' may also upload information about road surface irregularities obtained from the LiDAR 461 (or a camera) etc. in association with the location information.

For example, as shown in FIG. 41, LiDAR 461-1 may be provided in front of vehicle 481, and point cloud information of area ZF through which the vehicle is about to travel may be obtained to obtain unevenness information for area ZF. LiDAR 461-2 may be provided behind vehicle 481 to obtain unevenness information for area ZR so that point cloud information for area ZR through which the vehicle will travel when backing up may be obtained. The operation control unit 423'' may upload unevenness information for areas ZF, ZR, etc., together with position information, for example.

The operation control unit 423'' also compares the drive signal of the actuator 312 with the current value detected by the current sensor 462, and if they do not match, it can detect an abnormality in the actuator due to a broken wire or the like, and may also upload this actuator abnormality detection information.

In the cloud server 472, the optimal NC filter processing unit 332 is registered based on this information in accordance with the anticipated noise level for each location, driving conditions, etc., and this enables the operation control unit 423'' in the vehicle 1 used by a general user to select the optimal NC filter processing unit 332 based on its own location information and driving conditions.

<<18. Third embodiment>>
<Combination of FF type NC unit and FB type NC unit>
In the above, an FF type NC device has been described as the first embodiment, and an FB type NC device has been described as the second embodiment.

However, by combining both of these, more appropriate noise reduction can be achieved.

FIG. 42 shows an example of the configuration of an NC unit 33 realized for a vehicle 1 by combining a feedback-type NC unit 33B and a feedforward-type NC unit 33F.

Here, the FB type NC device 33B is composed of a sensor 311, an actuator 312 (which may be any of 312A to 312F), and an FBNC processing unit 313. Note that the FBNC processing unit 313 has a configuration corresponding to the NC processing unit 313, but hereafter it will be referred to as the FBNC processing unit 313 to make it easier to recognize that it is part of the FB type NC device 33.

Furthermore, the FF type NC device 33F is composed of a sensor 151, an FFNC processing unit 153 (or 153'), and a speaker 154. Note that the FFNC processing unit 153 corresponds to the NC processing unit 153, but hereafter it will be referred to as the FFNC processing unit 153 to make it easier to recognize that it is the FF type NC device 33F.

As described above, as shown in FIG. 42, the NC unit 33 for the vehicle 1 combines the FB type NC unit 33B and the FF type NC unit 33F, making it possible to appropriately reduce both noise that can only be reduced by the FB type NC unit 33B and noise that can only be reduced by the FF type NC unit 33F.

In the following, we will assume that the FF type NC device 33F described above has one of the configurations related to the first embodiment described above, and the FB type NC device 33B has one of the configurations related to the second embodiment described above.

However, it does not necessarily have to be the same as the configuration in the first and second embodiments, and it may be a general FF type NC device or FB type NC device. For example, the in-vehicle microphone 152 is not essential to the configuration of an FF type NC device, and it may be configured to realize feedback type NC processing only from the sensor signals of the other sensors 151.

<Application example of a combination of FF type NC unit and FB type NC unit>
Incidentally, the sudden noise generated when going over a step has a large amplitude and is unsteady, and it can be said that this type of noise should desirably be appropriately reduced by the NC device 33 .

However, in the FB type NC device 33, the NC processing section 313 performs NC processing after the sudden sound is input to the sensor 311, so even if a protective function such as muting is provided, the processing may not be completed in time, and abnormal noise may occur. In other words, with the FB type NC device 33F alone, not only is it not possible to adequately reduce noise caused by a sudden sound, but there is also a risk of unpleasant abnormal noise being generated.

The FB type NC unit 33B does not have a mechanism for detecting the sudden sounds that cause abnormal noises in advance, making it difficult to take measures to prevent the occurrence of abnormal noises.

Therefore, by applying a configuration that combines the FF type NC device 33F and the FB type NC device 33B, it is possible to make it possible to perform appropriate NC processing in the FB type NC device 33B even in the case of noise that is a sudden sound.

<Transmission of sudden sounds>
42, when a sudden sound occurs as a tire goes over a step, the part of the tire that comes into contact with the step becomes the vibration source SN of the sudden sound. When the vibration source SN is the tire, focusing on the vibration propagation path RB from the vibration source SN to the sensor 311 of the FB type NC device 33B and the vibration propagation path RF to the sensor 151 of the FF type NC device 33F, it is clear that the vibration propagation path RF is shorter than the vibration propagation path RB.

This is because the sensor 151 of the FF type NC device 33F is installed near the tires, which are the vibration source SN of road noise. As with road noise, the vibration source SN of the input of sudden noise caused by bumps is also near the tires, so the vibration transmission path RF to the sensor 151 of the FF type NC device F is shorter than the vibration transmission path RB to the sensor 311 of the FB type NC device 33B.

Therefore, as shown in FIG. 43, the sudden sound transmitted from the vibration source is transmitted to the sensor 151 of the FF type NC unit 33F a predetermined time ΔT according to the difference in the vibration transmission path before the sensor 311 of the FB type NC unit 33B.

In addition, in Figure 43, the upper part shows how the vibration of a sudden sound from the tire is transmitted to the FB sensor 311 and the FF sensor 151 via their respective vibration transmission paths. The middle part shows the time that has elapsed since the sudden sound occurred in the sensor 151 (FF sensor) of the feedforward type NC device 33F and the waveform of the detection value. Furthermore, the lower part shows the time that has elapsed since the sudden sound occurred in the sensor 151 (FB sensor) of the feedback type NC device 33B and the waveform of the detection value.

As shown in FIG. 43, the timing at which the sudden sound is detected by sensor 151 (FF sensor) is earlier than the timing at which the sudden sound is detected by sensor 311 (FB sensor) by a predetermined time ΔT that corresponds to the difference between the vibration propagation paths RF and RB.

In other words, the FB type NC device 33B uses the detection information from the sensor 151 (FF sensor), which can detect a sudden sound earlier than its own sensor 311, and mutes the output level to the actuator 312 within the predetermined time ΔT before it reaches the sensor 311 (FB sensor), making it possible to avoid the generation of abnormal noise.

In other words, by using the detection signal of the sensor 151 (FF sensor) installed to pick up road noise in the FF type NC device 33F and then in the FB type NC device 33B, it becomes possible for the FB type NC device 33B to obtain the sudden sound in advance, making it possible to suppress the occurrence of abnormal sounds caused by the sudden sound.

<Example of the configuration of an NC device that prevents sudden noise in an FB type NC device>
Next, with reference to Figures 44 and 45, an example of the configuration of an NC device that can realize appropriate NC processing by applying a configuration that combines an FF type NC device and an FB type NC device and thereby countering sudden sounds in the FB type NC device will be described.

In addition, in the NC unit 33H in FIG. 44, components having the same functions as the NC unit 33 in FIG. 42 are given the same reference numerals, and their explanation will be omitted as appropriate. Also, FIG. 44 is an image diagram of the NC unit 33H that is mounted on the vehicle 1 and is configured by combining an FF type NC unit and an FB type NC unit, and FIG. 45 is a block diagram of the NC unit 33H.

In FIG. 45, the sensor 151 of the FF type NC unit 33FF is written as the FF sensor 151, and will be referred to in the same manner hereinafter. Also, the sensor 311 of the feedback type NC unit 33FB is written as the FB sensor 311, and will be referred to in the same manner hereinafter.

The NC unit 33H in FIG. 44 differs from the NC unit 33 in FIG. 42 in that, instead of a combination of the FF type NC unit 33F and the FB type NC unit 33B, the NC unit 33H in FIG. 44 combines the FF type NC unit 33FF and the FB type NC unit 33FB, and further includes a sudden sound detection unit 501.

Furthermore, the FB type NC device 33FB differs from the FB type NC device 33B in that, in addition to the sensor 311, the actuator 312, and the FBNC processing unit 313, a volume adjustment unit 502 is provided that is controlled by the sudden sound detection unit 501 and adjusts the volume of the actuator drive signal output from the FBNC processing unit 313.

The FF type NC device 33FF has the same basic configuration as the FF type NC device 33F, but the sensor signal of the FF sensor 151 is output not only to the FFNC processing unit 153 but also to the sudden sound detection unit 501.

When the sudden sound detection unit 501 detects the occurrence of a sudden sound based on the sensor signal of the FF sensor 151, it controls the volume adjustment unit 502 in the NC device 33FB for a specified period of time to reduce the volume to a level close to mute and suppress noise caused by the sudden sound.

More specifically, if the sudden sound is a single sound (or occurs infrequently), as shown in the left part of FIG. 46, the sudden sound detection unit 501 controls the volume adjustment unit 502 for a predetermined period of time including the timing when a predetermined time ΔT has elapsed since the sudden sound was detected by the FF sensor 151 and until the sudden sound is detected by the FB sensor 311, to reduce the volume of the drive signal to the actuator 312 to a mute (or close to mute) level.

As a result, even if the FB type NC device 33FB detects a sudden sound by the FB sensor 311, the operation of the actuator 312 is essentially muted, thereby suppressing the generation of abnormal noise.

Also, depending on the road conditions, there may be cases where bumps occur periodically. In such cases, if muting is performed as long as sudden sounds are continuously detected, NC processing will be stopped even in sections where no sudden sounds are occurring, so there is a possibility that the noise will continue to be perceived.

As shown in the right part of Figure 46, when sudden sounds occur consecutively, the volume is set to be reduced to a mute (or close to mute) level until the sudden sound is detected by the FB sensor 311, and then increased to, for example, about half the reference value. By doing this, the feedback type NC device 33FB can continue NC processing while minimizing abnormal sounds caused by the operation of the actuator 312, even if a sudden sound is detected by the FB sensor 311.

In FIG. 46, the upper and middle waveforms show the change in detection level over time when the FF sensor 151 and the FB sensor 311 detect a sudden sound, respectively. The lower waveform shows the change in the volume of the drive signal for the actuator 312, which is adjusted by the volume adjustment unit 502 at the timing corresponding to the upper and middle waveforms.

<Countermeasures against sudden noise by the NC processing unit in FIG. 45>
Next, the sudden sound prevention process by the NC unit 33H in Fig. 45 will be described with reference to the flowchart in Fig. 47. The NC units 33FB and 33FF each execute the above-mentioned NC process.

In step S301, the sudden sound detection unit 501 controls the volume adjustment unit 502 to set the volume of the actuator drive signal output from the FBNC processing unit 313 to a reference value.

In step S302, the sudden sound detection unit 501 acquires a sensor signal from the FF sensor 151.

In step S303, the sudden sound detection unit 501 determines whether or not a sudden sound has occurred based on the sensor signal from the FF sensor 151.

If it is determined in step S303 that a sudden sound has occurred, processing proceeds to step S304.

In step S304, the sudden sound detection unit 501 determines whether or not sudden sounds are occurring continuously and periodically based on the sensor signal.

If it is determined in step S304 that sudden sounds are occurring continuously and periodically, processing proceeds to step S305.

In step S305, the sudden sound detection unit 501 controls the volume adjustment unit 502 to reduce the volume of the drive signal for the actuator 312 output from the FBNC processing unit 313 to a level close to mute.

In step S306, the sudden sound detection unit 501 determines whether or not it is time for the FB sensor 311 to detect a sudden sound based on the time that has elapsed since the FF sensor 151 detected the sudden sound, and repeats the same process until that time.

If it is determined in step S306 that the timing has come for the FB sensor 311 to detect a sudden sound, the process proceeds to step S307.

In step S307, the sudden sound detection unit 501 controls the volume adjustment unit 502 to set the volume of the drive signal of the actuator 312 output from the FBNC processing unit 313 to approximately half the reference value.

In step S308, the sudden sound detection unit 501 determines whether the FF sensor 151 has finished detecting the sudden sound, a predetermined time has elapsed, and the FB sensor 311 has stopped detecting the sudden sound, and repeats the same process until the FF sensor 151 has finished detecting the sudden sound and the predetermined time has elapsed.

If it is determined in step S308 that the FF sensor 151 has finished detecting the sudden sound and the predetermined time has elapsed, the process proceeds to step S309.

In step S309, the sudden sound detection unit 501 controls the volume adjustment unit 502 to return the volume of the drive signal of the actuator 312 output from the FBNC processing unit 313 to the reference value.

On the other hand, if it is determined in step S304 that sudden sounds are not occurring continuously and periodically, processing proceeds to step S311.

In step S311, the sudden sound detection unit 501 controls the volume adjustment unit 502 to reduce the volume of the drive signal for the actuator 312 output from the FBNC processing unit 313 to a level close to mute.

In step S312, the sudden sound detection unit 501 determines whether a predetermined time has elapsed since the FF sensor 151 detected the sudden sound, which is longer than the time the FB sensor 311 detected the sudden sound, and repeats the same process until the FF sensor 151 stops detecting the sudden sound and the predetermined time has elapsed.

If it is determined in step S312 that a predetermined time has elapsed since the FF sensor 151 detected the sudden sound, which is longer than the time the FB sensor 311 detected the sudden sound, the process proceeds to step S309.

If it is determined in step S303 that a sudden sound has not occurred, steps S304 to S309 and steps S311 and S312 are skipped.

In step S313, the sudden sound detection unit 501 determines whether or not an instruction to end the process has been given. If an instruction to end the process has not been given, the process returns to step S301, and the subsequent steps are repeated.

Then, in step S313, when an instruction to end the process is given, the process ends.

By the above process, when a single sudden sound is detected by the FF sensor 151, the drive signal of the actuator 312 is reduced to a state close to mute until a predetermined time including the timing when the sudden sound is detected by the FB sensor 311, making it possible to suppress the generation of abnormal noise due to the sudden sound.

In addition, when the FF sensor 151 detects a sudden sound that continues periodically, the drive signal of the actuator 312 is reduced to a state close to muted until the sudden sound is detected by the FB sensor 311, and then the drive signal is reduced to about half the reference value until the sudden sound detection ends and the sudden sound is no longer detected by the FB sensor 311. This makes it possible to continue NC processing while minimizing the impact of abnormal noise caused by sudden sounds.

<<19. First Modification of the Third Embodiment>>
In the above, an example has been described in which, when a sudden sound is detected, the volume of the drive signal output from the FBNC processing unit 313 to the actuator 312 is reduced for a predetermined period of time to suppress the generation of abnormal noise caused by the sudden sound.

However, the volume of the drive signal may be reduced by selectively using a band-cut filter that is suitable for the waveform of the sudden sound detected by the FF sensor 151.

FIG. 48 shows an example of the configuration of an NC processing unit 33H' that selectively uses a band-cut filter suited to the waveform of the sudden sound detected by the FF sensor 151 to reduce the volume of the drive signal.

In the configuration of the NC processing unit 33H' in FIG. 48, components having the same functions as those of the NC processing unit 33H in FIG. 44 are given the same reference numerals, and descriptions thereof will be omitted as appropriate.

The NC processing unit 33H' in FIG. 48 differs from the NC processing unit 33H in FIG. 44 in that a sudden sound detection unit 501', a filter search unit 511, a cutoff filter set storage unit 512, and a band cutoff processing unit 521 are provided instead of the sudden sound detection unit 501 and the volume adjustment unit 502.

The sudden sound detection unit 501' has the same basic functions as the sudden sound detection unit 501, but is equipped with a frequency analysis unit 501a. When a sudden sound is detected, the frequency analysis unit 501a is controlled to perform frequency analysis on the waveform of the sudden sound, and the analysis result is output to the filter search unit 511.

The filter search unit 511 accesses the cutoff filter set storage unit 512, which stores cutoff filters corresponding to various band characteristics, and searches for a cutoff filter with the corresponding band characteristics based on the analysis results, and supplies the searched filter to the band cutoff processing unit 521 of the NC unit 33FB.

The band blocking processing unit 521 performs band blocking processing using a blocking filter supplied by the filter search unit 511 on the drive signal output from the FBNC processing unit 313 to the actuator 312, and outputs the result.

Let us consider a case where the frequency analysis result for the waveform of the sudden sound supplied by the FF sensor 151 has characteristics indicated by a vibration level waveform such as that shown in the upper part of Figure 49.

In this case, the filter search unit 511 searches the cutoff filter set storage unit 512 for a cutoff filter that has a filter gain with band characteristics such as those shown in the lower part of Figure 49, which cancels out the band characteristics shown in the waveform in the upper part of Figure 49, and supplies the cutoff filter to the band cutoff processing unit 521.

<Sudden sound prevention processing by the NC processing unit in FIG. 48>
Next, the sudden sound countermeasure process by the NC processor 33H' in FIG. 48 will be described with reference to a flow chart in FIG.

In step S331, the filter search unit 511 controls the band cutoff processing unit 521 to stop processing by the cutoff filter, and sets the volume of the actuator drive signal output by the FBNC processing unit 313 to a reference value.

In step S332, the sudden sound detection unit 501' acquires a sensor signal from the FF sensor 151.

In step S333, the sudden sound detection unit 501' determines whether or not a sudden sound has occurred based on the sensor signal from the FF sensor 151.

If it is determined in step S333 that a sudden sound has occurred, processing proceeds to step S334.

In step S334, the sudden sound detection unit 501' controls the frequency analysis unit 501a to perform frequency analysis on the waveform indicating the sudden sound, and outputs the analysis result to the filter search unit 511.

In step S335, the filter search unit 511 accesses the cutoff filter set storage unit 512, searches for a cutoff filter with corresponding band characteristics based on the analysis results, and supplies the searched filter to the band cutoff processing unit 521 of the NC unit 33FB.

In step S336, the band blocking processing unit 521 performs band blocking processing using the blocking filter supplied by the filter search unit 511 on the drive signal output from the FBNC processing unit 313 to the actuator 312 for a predetermined period of time, and outputs the result to the actuator 312.

In step S337, the band blocking processing unit 521 stops the band blocking processing and sets the volume of the actuator drive signal output by the FBNC processing unit 313 to a reference value.

On the other hand, if it is determined in step S333 that a sudden sound has not occurred, steps S334 to S337 are skipped.

In step S338, the sudden sound detection unit 501' determines whether or not an instruction to end the process has been given. If an instruction to end the process has not been given, the process returns to step S331, and the subsequent steps are repeated.

Then, in step S338, when an instruction to end the process is given, the process ends.

By the above process, when a sudden sound is detected by the FF sensor 151, the frequency characteristics are analyzed from the waveform of the sudden sound, and the corresponding band-cut filter performs band-cut processing on the drive signal output from the FBNC processing unit 313 to the actuator 312, making it possible to suppress the generation of abnormal noise due to the sudden sound.

<<20. Second Modification of the Third Embodiment>>
In the above, an example has been described in which, when a sudden sound is detected, frequency analysis is performed, a corresponding band cutoff filter is selected, and band cutoff filter processing is performed on the drive signal output from the FBNC processing unit 313 to the actuator 312 for a predetermined period of time, thereby reducing the volume only at the timing when the sudden sound occurs, thereby suppressing the occurrence of abnormal sounds due to the sudden sound.

However, when processing using a band-stop filter, if frequency analysis is performed, then the corresponding band-stop filter is searched for and read, and supplied to the band-stop processing unit 521 for band-stop processing, the processing takes time, causing delays in processing and making it difficult to achieve proper NC processing.

Therefore, it is possible to perform parallel processing using band-stop filters with multiple band characteristics, and then selectively output a drive signal based on the frequency analysis results.

FIG. 51 shows an example of the configuration of an NC processing unit 33H'' that performs parallel processing using band-stop filters with multiple band characteristics, and then selectively outputs a drive signal based on the frequency analysis results.

In the configuration of the NC processing unit 33H'' in FIG. 51, components having the same functions as those of the NC processing unit 33H' in FIG. 48 are given the same reference numerals, and descriptions thereof will be omitted as appropriate.

The NC processing unit 33H'' in FIG. 51 differs from the NC processing unit 33H' in FIG. 48 in that the blocking filter set storage unit 512 and the band blocking processing unit 521 have been deleted, and a first band blocking filter 531-1 through an m-th band blocking filter 531-m and a selection unit (SEL) 532 have been provided.

The first band blocking filter 531-1 through the m-th band blocking filter 531-m are band blocking filters with various band characteristics stored in the blocking filter set storage unit 512, and perform the respective band blocking filter processing on the drive signal output from the FBNC processing unit 313 to the actuator 312, and output the result to the selection unit 532. Note that drive signals that have not been processed by the band blocking filters are also supplied to the selection unit 532.

The selection unit 532 is controlled by the filter search unit 511, and outputs to the actuator 312, from among the drive signals that have been filtered by the first band-cut filter 531-1 through the m-th band-cut filter 531-m, a drive signal that has been subjected to band-cut filter processing with corresponding band characteristics based on the frequency analysis results.

When switching the band-blocking filter 531, the selection unit 532 may switch the filter path by switching if low delay is the goal, but may also switch from the current filter path to the next filter path by cross-fading.

With this configuration, it is possible to selectively switch between drive signals that have been subjected to band-stop filter processing with band characteristics and output them to the actuator 312, based on the frequency analysis results, without loading a band-stop filter. As a result, it is possible to improve the processing speed and suppress failures of NC processing due to delays.

<Sudden sound prevention processing by the NC processing unit in FIG. 51>
Next, the sudden sound countermeasure process by the NC processor 33H' in FIG. 51 will be described with reference to the flowchart in FIG.

In step S341, the sudden sound detection unit 501' controls the selection unit 532 to select a drive signal that has not been processed by a band cutoff filter, and output it to the actuator 312. At this time, the first band cutoff filter 531-1 to the m-th band cutoff filter 531-m perform band cutoff filter processing on the drive signal according to their respective band characteristics, and continue to output the result to the selection unit 532.

In step S342, the sudden sound detection unit 501' acquires a sensor signal from the FF sensor 151.

In step S343, the sudden sound detection unit 501' determines whether or not a sudden sound has occurred based on the sensor signal from the FF sensor 151.

If it is determined in step S343 that a sudden sound has occurred, processing proceeds to step S344.

In step S344, the sudden sound detection unit 501' controls the frequency analysis unit 501a to perform frequency analysis on the waveform indicating the sudden sound, and outputs the analysis result to the filter search unit 511.

In step S345, the filter search unit 511 controls the selection unit 532 based on the frequency analysis result to select the drive signal that has been subjected to band-stop filter processing corresponding to the frequency analysis result from among the drive signals that have been subjected to band-stop filter processing by the first band-stop filter 531-1 to the mth band-stop filter 531-m for a predetermined period of time, and outputs the drive signal to the actuator 312.

In step S346, the selection unit 532 selects the drive signal that has not been processed by the band-blocking filter and outputs it to the actuator 312.

In step S347, the sudden sound detection unit 501' determines whether or not an instruction to end the process has been given. If an instruction to end the process has not been given, the process returns to step S342, and the subsequent steps are repeated.

Then, in step S347, when an instruction to end the process is given, the process ends.

The above process makes it possible to selectively output to the actuator 312 a drive signal that has been subjected to band-stop filter processing with band characteristics immediately based on the frequency analysis results, eliminating the need to reload a band-stop filter with different band characteristics based on the frequency analysis results. As a result, it is possible to improve the speed of sudden sound prevention processing, and to suppress NC processing failures due to delays.

<<21. Third Modification of the Third Embodiment>>
In the above, the presence or absence of a sudden sound is determined based on the sensor signal from the FF sensor 151, but a sensor other than the FF sensor 151 may be used to detect a sudden sound.

FIG. 53 shows an example configuration of an NC device 33H''' in which the sudden sound detection unit 501 detects unevenness in the road surface based on point cloud information detected by a LiDAR 541 that senses the road surface while traveling, in addition to the sensor signal from the FF sensor 151, and determines the presence or absence of a sudden sound based on the detected unevenness of the road surface.

In this way, when detecting a sudden sound based on the 3D point cloud detected by the LiDAR 541, the change in road surface conditions can be compared with the case where only the acceleration sensor is used, making it possible to determine in advance whether or not a sudden sound has occurred.

Furthermore, when it is recognized that a sudden sound is to be detected from the unevenness of the road surface detected by the LiDAR 541, a composite process may be performed in which the volume of the drive signal is muted first, and then a band-blocking filter is selected based on the sensor signal of the FF sensor 151.

The sudden sound countermeasure processing performed when a sudden sound is detected by the LiDAR 541 is the processing described with reference to the flowchart in FIG. 47, and the processing for selecting a band-blocking filter by the sensor signal of the FF sensor 151 is the processing described with reference to the flowchart in FIG. 50, so the description thereof will be omitted.

<<22. Fourth Modification of the Third Embodiment>>
In the above, the sensor signal of the FF sensor 151 has been used in the feedforward type NC processing unit 33FF, but the NC processing by the FF type NC processing unit 33FF may be performed using the sensor signal of the FB sensor 311.

Figures 54 and 55 show an example of the configuration of an NC device 33H'''' that performs NC processing by an FF type NC processing unit 33FF using the sensor signal of the FB sensor 311.

The NC unit 33H'''' in Figures 54 and 55 differs from the NC unit 33H in Figures 44 and 45 in that the NC unit 33FF is newly provided with an FB sensor-using FFNC processing unit 551 and an adder 552.

The FFNC processing unit using FB sensor 551 basically has the same functions as the FFNC processing unit 153, but differs in that it uses the sensor signal of the FB sensor 311 instead of the sensor signal of the FF sensor 151 for NC processing.

For example, as shown in FIG. 54, the noise NS, indicated by the dashed line, emitted from the front windshield FW is expected to reach the control point EP via acoustic spatial propagation. In other words, if the propagation distance from the speaker 154, which emits sound AS in the opposite phase to the noise NS, to the control point EP by the FF-type NC processing unit 33FF is shorter than the propagation distance of the noise NS emitted from the front windshield FW, the FF-type NC processing unit 33FF performs NC processing based on the sensor signal of the FB sensor 311, thereby realizing NC processing by canceling out the noise NS with the opposite phase sound AS at the control point EP.

Then, the FB sensor-using FFNC processing unit 551 generates an anti-phase sound using the sensor signal of the FB sensor 311 and outputs it to the adder 552.

The adder 552 adds the opposite phase sound generated by the FFNC processing unit 153 based on the sensor signal of the FF sensor 151 and the opposite phase sound generated by the FB sensor using FFNC processing unit 551 using the sensor signal of the FB sensor 311, and outputs the result as sound from the speaker 154.

With this configuration, the FF type NC device 33FF can reduce both the anticipated noise detected by the FF sensor 151 and the unknown noise detected by the FB sensor 311.

<NC processing by FF type NC device in Fig. 55>
Next, the NC processing by the FF type NC unit 33FF in FIG. 55 will be described with reference to the flowchart in FIG.

In step S351, the FFNC processing unit 153 executes FFNC (feedforward noise cancellation) processing using the FF sensor, generates an antiphase sound at the control point based on the sensor signal of the FF sensor 151, and outputs it to the adder 552. Note that the FFNC (feedforward noise cancellation) processing using the FF sensor is, for example, the NC processing of each component in the first embodiment.

In step S352, the FB sensor using FFNC processing unit 551 executes FB sensor using FFNC processing, generates an anti-phase sound at the control point based on the sensor signal of the FB sensor 311, and outputs it to the adder 552. Note that the FB sensor using FFNC (feed-forward type noise cancellation) processing is, for example, NC processing of each component in the first embodiment using the sensor signal of the FB sensor 311.

In step S353, the adder 552 adds the out-of-phase sound at the control point generated by the FFNC processing using the FF sensor and the out-of-phase sound at the control point generated by the FFNC processing using the FB sensor, and emits the result from the speaker 154 toward the control point.

The above process makes it possible for the FF-type NC device 33FF to reduce both the anticipated noise detected by the sensor 151 and the unknown noise detected by the sensor 311.

<<23. Fifth Modification of the Third Embodiment>>
In the above, the sensor signal of the FB sensor 311 has been used in the FB type NC unit 33FB, but the sensor signal of the FF sensor 151 may be used to execute NC processing by the FB type NC unit 33FB.

Figures 57 and 58 show an example configuration of NC unit 33H'''''' that executes NC processing by FB type NC unit 33FB using the sensor signal of FF sensor 151.

The NC unit 33H'''''' in Figures 57 and 58 differs from the NC unit 33H in Figures 44 and 45 in that the NC unit 33FB is newly provided with an FF sensor-using FBNC processing unit 571 and an adder 572.

The FF sensor-using FBNC processing unit 571 basically has the same functions as the FBNC processing unit 313, but differs in that it uses the sensor signal of the FF sensor 151 instead of the sensor signal of the FB sensor 311 for NC processing.

As mentioned above, when FB-type NC processing is performed on panels such as the front windshield FW, it becomes possible to control noise with an unknown vibration source.

On the other hand, the vibration-induced noise that propagates to the front windshield FW and is emitted is not limited to unknown noise, but is thought to include a certain amount of known noise as input.

Considering that the FF sensor 151 is close to the vibration source of the road noise, the sensor signal from the FF sensor 151 is used to vibrate the actuator 312, which allows the FBNC processing unit 313 to focus resources on countermeasures against noise emitted by unknown noise, and is expected to improve the NC performance of the feedback type NC device 33FB.

The FF sensor-using FBNC processing unit 571 generates a drive signal for the actuator 312 using the sensor signal of the FF sensor 151 and outputs it to the adder 552.

The adder 572 adds together the actuator drive signal generated by the FBNC processing unit 313 based on the sensor signal of the FB sensor 311 and the actuator drive signal generated by the FF sensor using FBNC processing unit 571 using the sensor signal of the FF sensor 151, and supplies the result to the actuator 312 via the volume adjustment unit 502 to vibrate it.

With this configuration, in the FB type NC device 33FB, known components contained in the unknown noise can be reduced by NC processing using the sensor signal of the FF sensor 151, and pure unknown noise can be reduced by NC processing using the sensor signal of the FB sensor 311, making it possible to improve noise reduction performance.

<NC processing by FB type NC device in Fig. 58>
Next, NC processing by the FB type NC unit 33FB in FIG. 58 will be described with reference to the flowchart in FIG.

In step S371, the FBNC processing unit 313 executes FBNC (feedback type noise cancellation) processing using the FB sensor, generates an actuator drive signal based on the sensor signal of the FB sensor 311, and outputs it to the adder 572. Note that the FB sensor use FFNC (feedback type noise cancellation) processing is, for example, the NC processing of each component in the second embodiment.

In step S372, the FF sensor using FBNC processing unit 571 executes FF sensor using FBNC processing, generates a drive signal for the actuator 312 based on the sensor signal of the FF sensor 151, and outputs it to the adder 572. Note that the FF sensor using FBNC (feedback type noise cancellation) processing is, for example, NC processing of each component in the second embodiment using the sensor signal of the FF sensor 151.

In step S373, the actuator drive signal generated by the FBNC processing unit 313 based on the sensor signal of the FB sensor 311 is added to the actuator drive signal generated by the FF sensor using FBNC processing unit 571 using the sensor signal of the FF sensor 151, and the result is supplied to the actuator 312 via the volume adjustment unit 502 to vibrate it.

By performing the above process, the FB type NC device 33FB is able to reduce both the anticipated noise detected by the sensor 151 and the unknown noise detected by the sensor 311.

<<24. Sixth Modification of the Third Embodiment>>
The above has described an example configuration of an NC unit 33H''''' that combines one FF type NC unit 33FF and one FB type NC unit 33FB to perform NC processing by the FB type NC unit 33FB based on a sensor signal from the FF sensor 151, or an NC unit 33H'''' that performs NC processing by the FF type NC processing unit 33FF based on a sensor signal from the FB sensor 311.

However, the number of FF type NC units 33FF and FB type NC units 33FB may be other than the above combination, and the sensor signal of the FF sensor 151 may be used to perform NC processing by the feedback type NC unit 33FB, and the sensor signal of the FB sensor 311 may be used to perform NC processing by the FF type NC processing unit 33FF.

Figures 60 and 61 show an example of the configuration of an NC unit 33H'''''''', which is configured by combining one FF type NC unit 33FF and two FB type NC units 33FB-1 and 33FB-2. In this example, as shown in Figure 60, the FB type NC unit 33FB-1 is provided on the front window, and the FB type NC unit 33FB-2 is provided on the roof window.

The single FF-type NC unit 33FF executes FF-type NC processing using the sensor signals of the FF sensor 151 as well as the sensor signals of the FB sensors 311-1 and 311-2 of the FB-type NC units 33FB-1 and 33FB-2.

The two FB type NC devices 33FB-1 and 33FB-2 also realize FB type NC processing using the sensor signal of the FF sensor 151 in addition to the sensor signals of the FB sensors 311-1 and 311-2, respectively.

The FF-type NC device 33FF is equipped with FF sensors 151-1 to 151-x, an in-vehicle microphone 152, an FFNC processor 153, a speaker 154, as well as FB sensor-using FFNC processors 551-1 and 551-2 and adders 552-1 and 552-2.

The FB sensor-using FFNC processing unit 551-1 executes FF-type NC processing based on the sensor signals of the FB sensors 311-1-1 to 311-1-y1 of the FB-type NC device 33FB-1, and outputs the processed result, an antiphase sound, to the adder 552-1.

The FB sensor-using FFNC processing unit 551-2 executes FF-type NC processing based on the sensor signals of the FB sensors 311-2-1 to 311-2-y1 of the FB-type NC device 33FB-2, and outputs the processed result, an antiphase sound, to the adder 552-2.

The adder 552-1 adds the opposite phase audio output from the FFNC processing unit 153 and the opposite phase audio output from the FB sensor using FFNC processing unit 551-1, and outputs the result to the adder 552-2.

The adder 552-2 adds the opposite phase sound supplied by the adder 552-1 and the opposite phase sound output from the FB sensor using FFNC processing unit 551-2, and emits the sound from the speaker 154. That is, the adders 552-1 and 552-2 add the opposite phase sounds generated by the FFNC processing unit 153 and the FB sensor using FFNC processing units 551-1 and 551-2, respectively, and emit the sound from the speaker 154.

The individual configurations of the FB type NC devices 33FB-1 and 33FB-2 are the same as those shown in Figures 57 and 58, so their explanation will be omitted.

The sudden sound detection unit 501' basically has the same functions as the sudden sound detection unit 501, but when a sudden sound is detected, the sudden sound is suppressed by reducing the volume of the volume adjustment units 502-1 and 502-2 of the FB type NC devices 33FB-1 and 33FB-2.

The NC processing by the NC unit 33H in Figure 61 is basically the same as the processing described above, so a description of it will be omitted.

<<25. Seventh Modification of the Third Embodiment>>
In the above, an example has been described in which the sudden sound detection unit 501' detects a sudden sound and then reduces the volume of the volume adjustment units 502-1, 502-2 of the FB type NC units 33FB-1, 33FB-2 to suppress the occurrence of a sudden sound.

However, the presence or absence of a sudden sound may be detected based on not only the sensor signal of the FF sensor 151 but also all of the sensor signals of the FB sensor 311, and the volume of the actuator drive signal may be managed in a centralized manner according to the position of the sensor where the sudden sound is detected, thereby implementing sudden sound countermeasure processing.

FIG. 62 shows an example of the configuration of an NC device 33H that detects the presence or absence of a sudden sound based on not only the sensor signal of the FF sensor 151 but also all of the sensor signals of the FB sensor 311, and centrally controls the volume of the actuator drive signal according to the position of the sensor where the sudden sound is detected.

The NC unit 33H in FIG. 62 differs from the NC processing unit 33H in FIG. 61 in that a centralized control type sudden sound detection unit 501'' is provided instead of the sudden sound detection unit 501'.

The centralized control type sudden sound detection unit 501'' acquires sensor signals from all of the FF sensors 151-1 to 151-x and the FB sensors 311-1-1 to 311-1-y1, and 311-2-1 to 311-2-y2, and determines whether or not a sudden sound has occurred.

If the sudden sound is caused by the FF sensor 151, the sudden sound countermeasure processing is realized by the above-mentioned processing.

In addition, when the sudden sound is detected by the FB sensor 311, the volume adjustment units 502-1 and 502-1 are controlled to mute the sound in an order and timing that corresponds to the position of the FB sensor 311 where the sudden sound was detected.

For example, if a sudden change in air pressure, such as when entering a tunnel, is detected by the FB sensor 311-1 on the front window FW and a sensor signal greater than a predetermined value is detected, it is considered that a sudden sound has been detected, and this may result in sudden vibration due to aerodynamic forces.

In such a case, the timing at which a sudden sound is detected by the sensor 311-1 of the front windshield FW may be used as a trigger to control the volume adjustment unit 502-2 in the FB type NC device 33FB-2 to reduce the volume in accordance with the timing at which a sudden sound is detected on the roof window, thereby implementing a sudden sound countermeasure process for the FB type NC device 33FB-2.

In other words, a centralized, centrally controlled type of sudden sound prevention processing can be realized by controlling the volume according to the vibration propagation distance to the feedback type NC device 33FB other than the FB sensor 311 of the front window FB, which has received an input above a predetermined threshold.

In the above, we have described an example in which the volume of the actuator drive signal is adjusted when a sudden sound is detected based on the sensor signal detected by the FF sensor 151 or the FB sensor 311.

However, when a sudden sound is detected based on the sensor signal detected by the FF sensor 151 or the FB sensor 311, the volume of the sound emitted from the speaker 154 may be adjusted.

In other words, the out-of-phase audio signal output from the FFNC processing unit 153 and the FB sensor using FFNC processing unit 551 for outputting sound from the speaker 154 can also be considered as a drive signal for driving the speaker 154.

Therefore, a volume adjustment unit X (not shown) corresponding to the volume adjustment unit 502, which adjusts the volume of a drive signal consisting of an audio signal of opposite phase for driving the speaker 154, may be provided, for example, between the adder 552-2 in FIG. 62 and the speaker 154.

Then, when the centralized control type sudden sound detection unit 501'' detects a sudden sound based on the sensor signal detected by the FF sensor 151 or the FB sensor 311, the centralized control type sudden sound detection unit 501'' may control the volume adjustment unit X (not shown) to adjust the volume of the sound emitted from the speaker 154, for example, to be lower.

<<26. Eighth Modification of the Third Embodiment>>
Although an example has been described above in which the FF type NC unit 33FF and the FB type NC unit 33FB are combined, it is also possible to freely set which functions are to be used or not.

For example, it may be possible to allow the settings to be freely set through intuitive operations using a GUI 601 as shown in FIG. 63.

In Figure 63, the configuration of NC unit 33H'''''''' in Figure 62 is displayed, and whether or not to enable the function can be set by turning on or off SW611-1 to 611-6, etc.

SW611-1 is a switch that sets whether or not to output the processing results of the FF sensor-using FBNC processing unit on the front window side.

SW611-2 is a switch that sets whether or not the centralized control type sudden sound detection unit controls the volume of the drive signal for the actuator on the front window side when it detects a sudden sound.

SW611-3 is a switch that sets whether or not to output the processing results of the FF sensor-using FBNC processing unit on the roof window side.

SW611-4 is a switch that sets whether or not the centralized control type sudden sound detection unit controls the volume of the drive signal for the actuator on the roof window side when it detects a sudden sound.

SW611-5 and 611-6 are switches that set whether or not to output the processing results of the two FFNC processing units using the FB sensor.

When you tap SW611-1 through 611-6 once, they are displayed in a solid frame to indicate that they are set to on, and when you tap them again, they are displayed in a dotted frame to indicate that they are set to off.

In FIG. 63, it is shown that SW611-1, 611-2, and 611-5 are set to ON, and SW611-3, 611-4, and 611-6 are set to OFF.

<<27. Examples of execution by software>>
The above-mentioned series of processes can be executed by hardware, but can also be executed by software. When the series of processes are executed by software, the programs constituting the software are installed from a recording medium into a computer built into dedicated hardware, or into, for example, a general-purpose computer capable of executing various functions by installing various programs.

Figure 64 shows an example of the configuration of a general-purpose computer. This computer has a built-in CPU (Central Processing Unit) 1001. An input/output interface 1005 is connected to the CPU 1001 via a bus 1004. A ROM (Read Only Memory) 1002 and a RAM (Random Access Memory) 1003 are connected to the bus 1004.

Connected to the input/output interface 1005 are an input unit 1006 consisting of input devices such as a keyboard and mouse through which the user inputs operation commands, an output unit 1007 which outputs a processing operation screen and images of the processing results to a display device, a storage unit 1008 consisting of a hard disk drive for storing programs and various data, and a communication unit 1009 consisting of a LAN (Local Area Network) adapter and the like, which executes communication processing via a network such as the Internet. Also connected is a drive 1010 which reads and writes data to removable storage media 1011 such as a magnetic disk (including a flexible disk), an optical disk (including a CD-ROM (Compact Disc-Read Only Memory) and a DVD (Digital Versatile Disc)), a magneto-optical disk (including an MD (Mini Disc)), or a semiconductor memory.

The CPU 1001 executes various processes according to a program stored in the ROM 1002, or a program read from a removable storage medium 1011 such as a magnetic disk, optical disk, magneto-optical disk, or semiconductor memory and installed in the storage unit 1008, and loaded from the storage unit 1008 to the RAM 1003. The RAM 1003 also stores data necessary for the CPU 1001 to execute various processes, as appropriate.

In a computer configured as described above, the CPU 1001 loads a program stored in the storage unit 1008, for example, into the RAM 1003 via the input/output interface 1005 and the bus 1004, and executes the program, thereby performing the above-mentioned series of processes.

The program executed by the computer (CPU 1001) can be provided, for example, by recording it on a removable storage medium 1011 such as a package medium. The program can also be provided via a wired or wireless transmission medium such as a local area network, the Internet, or digital satellite broadcasting.

In a computer, a program can be installed in the storage unit 1008 via the input/output interface 1005 by inserting the removable storage medium 1011 into the drive 1010. The program can also be received by the communication unit 1009 via a wired or wireless transmission medium and installed in the storage unit 1008. Alternatively, the program can be pre-installed in the ROM 1002 or storage unit 1008.

The program executed by the computer may be a program in which processing is performed chronologically in the order described in this specification, or a program in which processing is performed in parallel or at the required timing, such as when called.

The CPU 1001 in FIG. 64 realizes the functions of the NC unit 33.

In addition, in this specification, a system refers to a collection of multiple components (devices, modules (parts), etc.), regardless of whether all the components are in the same housing. Therefore, multiple devices housed in separate housings and connected via a network, and a single device in which multiple modules are housed in a single housing, are both systems.

Note that the embodiments of this disclosure are not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of this disclosure.

For example, the present disclosure can be configured as a cloud computing system in which a single function is shared and processed collaboratively by multiple devices over a network.

In addition, each step described in the above flowchart can be executed by a single device, or can be shared and executed by multiple devices.

Furthermore, when a single step includes multiple processes, the processes included in that single step can be executed by a single device, or can be shared and executed by multiple devices.

The present disclosure can also be configured as follows.
<1> An acceleration sensor that detects the acceleration of an object that emits sound by vibration;
A vibration device that vibrates the object;
a filter processing unit that performs noise cancellation filtering on a sensor signal that is a detection result of the acceleration sensor, thereby generating a drive signal for exciting the vibration device so as to suppress vibration of the object;
A drive unit in which the vibration device is stored;
a base portion for fixing the driving portion to the object,
The acceleration sensor is disposed on the base portion,
The noise suppression device, wherein the base portion and the drive portion are detachably connected to each other.
<2> The noise suppression device according to <1>, wherein the base portion and the drive portion are detachably connected to each other by a bolt.
<3> A convex portion is formed on the base portion,
The driving unit includes a voice coil, a bobbin having a cylindrical shape and through which a shaft of the voice coil is inserted so as to be slidable, and a base plate provided at a bottom of the bobbin,
The bolt connects the base portion and the drive portion by having a screw portion pass through a hole portion provided at the center of the base plate and engage with a screw hole provided at the center of the top of the convex portion.
<4> The noise suppression device according to <3>, wherein wiring connection portions are formed at opposing positions of the base plate and the top of the protrusion.
<5> The noise suppression device according to <1>, wherein the base portion and the drive portion are detachably connected to each other by a connector.
<6> The driving unit includes a voice coil, a cylindrical bobbin through which a shaft of the voice coil is inserted and which is slidable, and a base plate provided at a bottom of the bobbin and larger than a diameter of the bobbin,
The base portion is provided with a protrusion having a screw thread formed on an outer periphery thereof,
The connecting device has a cylindrical configuration with approximately the same diameter as the convex portion, a screw thread formed on the inside, and a lid with an opening with approximately the same diameter as the bobbin at the top through which the bobbin is inserted, the base plate is placed under the lid, and when the base plate is abutted against the top of the convex portion, the screw thread of the convex portion and the screw thread formed on the inside of the base plate engage with each other, thereby removably connecting the base portion and the drive unit by the connecting device.
<7> The driving unit includes a voice coil, a cylindrical bobbin through which a shaft of the voice coil is inserted and which is slidable, and a base plate provided at a bottom of the bobbin and larger in diameter than the bobbin,
The base portion has a protrusion having a screw hole formed on a side surface of an outer periphery thereof,
The connecting device has a cylindrical configuration having approximately the same diameter as the convex portion, and a lid with an opening having approximately the same diameter as the bobbin is formed at the top, through which the bobbin is inserted, the base plate is placed under the lid, and with the base plate abutting the top of the convex portion, a screw is inserted through the side and engages with the screw hole in the base portion, thereby removably connecting the base portion and the drive unit by the connecting device. The noise suppression device described in <5>.
<8> The base portion has a convex portion having a screw hole formed at the center of the top of the head,
The driving unit includes a voice coil, a bobbin having a cylindrical shape and through which a shaft of the voice coil is inserted so as to be slidable, and a base plate provided at a bottom of the bobbin and having a threaded portion;
The noise suppression device according to <1>, wherein the screw portion is screwed into the screw hole of the protrusion, thereby connecting the base portion and the drive portion.
<9> The drive unit,
Further, the acceleration sensor detects the movement of the driving unit, and is different from the acceleration sensor.
The noise suppression device according to claim 1, further comprising: a sensor for detecting an abnormality in the drive unit based on information regarding vibration of the object obtained from the acceleration sensor and information regarding movement of the drive unit obtained from the other acceleration sensor.
<10> The drive unit,
Further, the acceleration sensor detects the movement of the driving unit, and is different from the acceleration sensor.
The noise suppression device according to claim 1, further comprising: a drive signal for exciting the vibration device based on information regarding the vibration of the object obtained from the acceleration sensor and information regarding the movement of the drive unit obtained from the other acceleration sensor.
<11> The vibration device has a damper,
The filter processing unit includes a plurality of units that perform filter processing according to the temperature characteristics of the damper,
The noise suppression device according to <1>, further comprising a switching unit that switches among a plurality of filter processing units according to a temperature of the damper.
<12> The noise suppression device according to <11>, wherein the temperature is a temperature estimated based on a temperature inside the vehicle compartment and a temperature outside the vehicle compartment.
<13> The noise suppression device according to <11>, wherein the temperature is a temperature of the damper estimated based on direct sunlight determined from a direction of the sun at a current position calculated based on a compass, position information, and date and time information.

33, 33B, 33F, 33FB, 33FF, 33H, 33H' to 33H'''''''' NC device, 151, 151-1 to 151-n Sensor (FF sensor), 152 In-vehicle microphone, 153, 153' NC processing unit (FFNC processing unit), 154 Speaker, 171 Sensor filter design unit, 172 Sensor filter set memory unit, 173 Cancellation filter set memory unit, 174 Corresponding filter acquisition unit, 175 NC signal calculation unit, 181, 181' Filter generation processing unit, 182 Control point proximity microphone, 191 Cancellation filter design unit, 192 Correspondence storage processing unit, 211 Vehicle exterior microphone, 221 Vehicle exterior sound determination unit, 251, 251' DNN inference unit, 252, 252' Learned model memory unit, 253 Filter search unit, 254 Cancellation filter memory unit, 255 NC signal calculation unit, 271, 271' Cancellation filter design unit, 272 Filter record control unit, 273, 273' DNN learning unit, 311, 311', 311'' Sensor (FB sensor 312, 312A to 312G actuator, 312Ba to 312Ga drive unit, 312Bb to 312Gb base unit, 313, 313' NC processing unit (FBNC processing unit), 331 amplifier, 332, 332-1 to 332-n, 332c, 332h NC filter processing unit, 333 amplifier, 371 base plate, 372 bolt, 382a, 382b wiring connection unit, 391, 401 connector, 402 screw, 421 switch, 421' switching unit, 422 Switch, 423, 423', 423'', operation control section, 441, sun direction calculation section, 501, 501', sudden sound detection section, 501'', centralized control type sudden sound detection section, 502, volume adjustment section, 511, filter search section, 512, cutoff filter set storage section, 531, 531-1 to 531-m, first band cutoff filter to mth band cutoff filter, 532, selection section, 551, FFNC processing section using FB sensor, 552, adder, 571, FBNC processing section using FF sensor, 572, adder

Claims (13)

1. an acceleration sensor that detects the acceleration of an object that produces sound through vibration;
   A vibration device that vibrates the object;
   a filter processing unit that performs noise cancellation filtering on a sensor signal that is a detection result of the acceleration sensor, thereby generating a drive signal for exciting the vibration device so as to suppress vibration of the object;
   A drive unit in which the vibration device is stored;
   a base portion for fixing the driving portion to the object,
   The acceleration sensor is disposed on the base portion,
   The noise suppression device, wherein the base portion and the drive portion are detachably connected to each other.
2. The noise suppression device according to claim 1 , wherein the base portion and the drive portion are detachably connected to each other by a bolt.
3. A protrusion is formed on the base portion,
   The driving unit includes a voice coil, a bobbin having a cylindrical shape and through which a shaft of the voice coil is inserted so as to be slidable, and a base plate provided at a bottom of the bobbin,
   3. The noise suppression device according to claim 2, wherein the bolt connects the base portion and the drive portion by having a screw portion pass through a hole portion provided at the center of the base plate and mesh with a screw hole provided at the center of the top of the convex portion.
4. The noise suppression device according to claim 3 , wherein wiring connection portions are formed at opposing positions on the base plate and the top of the protrusion.
5. The noise suppression device according to claim 1 , wherein the base portion and the drive portion are detachably connected to each other by a connector.
6. The driving unit includes a voice coil, a bobbin having a cylindrical shape and through which a shaft of the voice coil is inserted so as to be slidable, and a base plate provided at a bottom of the bobbin and having a diameter larger than that of the bobbin,
   The base portion is provided with a protrusion having a screw thread formed on an outer periphery thereof,
   6. The noise suppression device according to claim 5, wherein the connecting device is tubular and has approximately the same diameter as the convex portion, a screw thread formed on the inside, and a lid having an opening at the top, the opening being approximately the same diameter as the bobbin, through which the bobbin is inserted, the base plate is positioned under the lid, and when the base plate is in contact with the top of the convex portion, the screw thread of the convex portion engages with the screw thread formed on the inside of the base plate, thereby removably connecting the base portion and the drive portion by the connecting device.
7. The driving unit includes a voice coil, a bobbin having a cylindrical shape and through which a shaft of the voice coil is inserted so as to be slidable, and a base plate provided at a bottom of the bobbin and having a diameter larger than that of the bobbin,
   The base portion has a protrusion having a screw hole formed on a side surface of an outer periphery thereof,
   6. The noise suppression device according to claim 5, wherein the connecting device is tubular and has approximately the same diameter as the convex portion, and a lid is formed at the top with an opening having approximately the same diameter as the bobbin, through which the bobbin is inserted, the base plate is placed under the lid, and with the base plate abutting the top of the convex portion, a screw is inserted through the side and engages with the screw hole in the base portion, thereby detachably connecting the base portion and the drive portion by the connecting device.
8. The base portion has a protrusion having a screw hole formed at the center of the top of the head,
   The driving unit includes a voice coil, a bobbin having a cylindrical shape and through which a shaft of the voice coil is inserted so as to be slidable, and a base plate provided at a bottom of the bobbin and having a threaded portion,
   The noise suppression device according to claim 1 , wherein the screw portion is screwed into the screw hole of the protrusion to connect the base portion and the drive portion.
9. The drive unit is
   Further, the acceleration sensor detects the movement of the driving unit, and is different from the acceleration sensor.
   2. The noise suppression device according to claim 1, wherein an abnormality in the drive unit is detected based on information regarding vibration of the object obtained from the acceleration sensor and information regarding movement of the drive unit obtained from the other acceleration sensor.
10. The drive unit is
    Further, the acceleration sensor detects the movement of the driving unit, and is different from the acceleration sensor.
    The noise suppression device according to claim 1 , further comprising: a drive signal for exciting the vibration of the vibration excitation device, the drive signal being generated based on information regarding vibration of the object obtained from the acceleration sensor and information regarding movement of the drive unit obtained from the other acceleration sensor.
11. The vibration device has a damper,
    The filter processing unit includes a plurality of units that perform filter processing according to the temperature characteristics of the damper,
    The noise suppression device according to claim 1 , further comprising a switching unit that switches one of a plurality of filter processing units according to a temperature of the damper.
12. The noise suppression device according to claim 11 , wherein the temperature is an estimated temperature based on an interior temperature and an exterior temperature of the vehicle.
13. The noise suppression device according to claim 11 , wherein the temperature is a temperature of the damper estimated based on direct sunlight determined from a direction of the sun at a current position calculated based on a compass, position information, and date and time information.

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