JP2020056628A - Signal processor, sensor system, alarm system, and vehicle - Google Patents

Abstract

To provide a signal processor capable of distinguishing between people sitting and non-person objects on a seat, a sensor system, an alarm system, and a vehicle.SOLUTION: A signal processor 22 includes a distance-measuring unit 22b, a determination part 22c, and an output part 22d. The distance measuring unit 22b measures the distance to an object on the basis of a sensor signal output from a sensor device 21. The determination part 22c determines whether or not an object is a person on the basis of variation in measured values of the multiple distances in a predetermined period. The output part 22d generates a human detection signal on the basis of the determination result by the determination part 22c and outputs the human detection signal. The determination part 22c makes an affirmative determination when the variation of the multiple measured values is less than a threshold value, and makes a negative determination when the variation of the measured values is more than the threshold value.SELECTED DRAWING: Figure 6

Description

  The present disclosure relates to a signal processing device, a sensor system, an alarm system, and a vehicle.

  Patent Literature 1 discloses an intrusion detection device that detects an intrusion of an automobile into a vehicle. The intrusion detection device includes a detection sensor and a signal processing circuit. The detection sensor outputs, as an output signal, a signal transmitted to the object and a Doppler signal obtained from the signal reflected from the object and returned. The signal processing circuit calculates a variance value of a frequency of the output signal during a predetermined period, and extracts an amplitude value of the output signal during a predetermined period. When the variance of the frequency of the output signal and the amplitude of the output signal exceed the respective threshold values, the signal processing circuit determines that there is a movement of a person in the vehicle and that the vehicle enters the vehicle.

JP 2010-210500 A

  The intrusion detection device of Patent Document 1 can detect a person in the vehicle when the movement of the person in the vehicle is relatively large, but cannot detect a person in the vehicle when the movement of the person in the vehicle is relatively small. Therefore, it is difficult for the intrusion detection device of Patent Literature 1 to distinguish a person sitting on the seat from an object other than the person on the seat.

  Therefore, an object of the present disclosure is to provide a signal processing device, a sensor system, an alarm system, and a vehicle that can distinguish a person sitting on a seat from an object other than a person on the seat.

  A signal processing device according to an aspect of the present disclosure includes a distance measurement unit, a determination unit, and an output unit. The distance measuring unit intermittently measures a distance to an object based on a sensor signal output by one or more sensor devices. The determination unit determines whether the object is a person based on a variation in a plurality of measured values of the distance during a predetermined period. The output unit generates a human detection signal based on the determination result of the determination unit, and outputs the human detection signal. Then, the determination unit makes an affirmative determination if the variation of the plurality of measurement values is less than a threshold, and makes a negative determination if the variation of the plurality of measurement values is equal to or greater than the threshold.

  A sensor system according to an aspect of the present disclosure includes a sensor device that outputs a sensor signal including information on a distance to an object in a detection area, and the above-described signal processing device.

  An alarm system according to an aspect of the present disclosure includes at least one sensor system described above and a notification system that receives the human detection signal from the sensor system. The notification system is a seatbelt monitoring unit that monitors whether the state of the seatbelt of the target seat is a coupled state or a disengaged state, and when the state of the seatbelt of the target seat is the disengaged state, A notification unit that outputs an alarm when a human detection signal is received.

  A vehicle according to an aspect of the present disclosure includes the above-described alarm system and a vehicle body including the alarm system.

  As described above, the present disclosure has an effect that a person sitting on a seat and an object other than a person on the seat can be distinguished.

FIG. 1 is a schematic diagram illustrating a sensor system including a signal processing device, an alarm system, and a vehicle according to an embodiment. FIG. 2 is a side view showing the partially broken vehicle according to the first embodiment. FIG. 3 is a block diagram showing the alarm system of the above. FIG. 4A is a plan view showing a first configuration example of a room lamp unit to which the above sensor device is attached. FIG. 4B is a plan view showing a second configuration example of the room lamp unit to which the sensor device is attached. FIG. 4C is another plan view showing a second configuration example of the room lamp unit of the above. FIG. 5 is a plan view showing another room lamp unit to which the sensor device is attached. FIG. 6 is a block diagram showing the sensor system of the above. FIG. 7A is a plot diagram showing measured values in the above signal processing device. FIG. 7B is a plot diagram showing another measured value in the signal processing device of the above. FIG. 8 is a block diagram showing a notification system provided in the alarm system of the above. FIG. 9 is a block diagram illustrating a sensor system according to a modification of the embodiment.

  The following embodiments relate generally to signal processing devices, sensor systems, alarm systems, and vehicles. More specifically, the present invention relates to a signal processing device for detecting a person, a sensor system, an alarm system, and a vehicle. Note that the embodiment described below is merely an example of an embodiment of the present disclosure. The present disclosure is not limited to the following embodiments, and various modifications can be made according to the design and the like as long as the effects of the present disclosure can be obtained.

  1 and 2 show a vehicle 9 provided with an alarm system 1 of the present embodiment. The vehicle 9 is, for example, a passenger car including a vehicle body 90 on which a plurality of occupants can ride. In FIG. 1, a virtual length axis X1 along the length of the vehicle 9 and a virtual width axis X2 along the width of the vehicle 9 are shown together with the vehicle 9. One of the two directions that are opposite to each other along the length axis X1 is the front direction, and the other is the rear direction. Of the two directions that are opposite to each other along the width axis X2, one is to the left and the other is to the right. In FIGS. 1 and 2, the above-described leftward and rightward directions are defined based on a person looking forward. The vehicle 9 is not limited to a passenger car, but may be any vehicle that transports people, baggage, or articles.

  A plurality of seats such as a front seat 41 and a rear seat 42 are installed in a cabin R1 of the vehicle 9. Specifically, a front seat 41 is arranged at the front of the cabin R1, and two rear seats 42 are arranged side by side at the rear of the cabin R1. The front seat 41 has a driver seat 411 and a passenger seat 412 arranged side by side.

  The alarm system 1 is provided in the vehicle 9 and is configured to output an alarm when the vehicle 9 is running and a person present in the detection area 6 does not wear a seat belt. The alarm system 1 of the present embodiment includes three sensor systems 2 and one notification system 3. The notification system 3 determines whether to output an alarm based on the detection results of the three sensor systems 2 and the state of each seat belt in the passenger compartment R1.

  Hereinafter, the sensor system 2 will be described in detail.

  The sensor system 2 is attached to the ceiling 5 (see FIG. 2) of the passenger compartment R1, and includes a sensor device 21 and a signal processing device 22, as shown in FIG. The sensor device 21 is a radio wave sensor. The sensor device 21 transmits a radio wave (transmission wave) to the detection area 6 in the passenger compartment R1, receives a radio wave (reflected wave) reflected by the object 7 (see FIG. 2) in the detection area 6, It outputs a sensor signal including information on the distance from the device 21 to the object 7. The signal processing device 22 receives a sensor signal output from the sensor device 21 via a communication line. The signal processing device 22 can determine whether or not the object 7 in the detection area 6 is a person by performing signal processing on the sensor signal output from the sensor device 21. Note that the sensor device 21 is not limited to a radio wave sensor, and may be, for example, an infrared sensor or an ultrasonic sensor.

  In the present embodiment, three sensor systems 2 are installed in the cabin R1, and detection areas 61, 62, and 63 are set as three detection areas 6 in the cabin R1 (see FIG. 1). The sensor system 2 is preferably arranged in a room lamp unit 8 installed on the ceiling 5 (see FIGS. 1 and 2). 1 and 2, two room lamp units 8 are illustrated, and when distinguishing the two room lamp units 8, the two room lamp units 8 are referred to as room lamp units 81 and 82, respectively.

  The room lamp unit 81 is a rear-seat interior light, and is located above the seating surface of the rear seat 42 at the center of the width of the passenger compartment R1. FIG. 4A shows a first configuration example of the room lamp unit 81. The room lamp unit 81 has a box-shaped unit main body 810 generated by resin molding or the like, and the unit main body 810 is attached to the ceiling 5. A translucent cover 811 is attached to the lower surface of the unit main body 810, and light transmitted through the cover 811 illuminates the vicinity of the rear seat 42. Two more sensor systems 2 are attached to the unit body 810 side by side. Each sensor device 21 of the two sensor systems 2 is located on the lower surface of the unit main body 810 side by side.

  Each of the two sensor devices 21 provided in the room lamp unit 81 corresponds to a corresponding one of the two rear seats 42, and transmits a transmission wave toward the corresponding rear seat 42, respectively. Receive the reflected wave. In this case, two detection areas 6 are formed by the two sensor devices 21 provided in the room lamp unit 81. The two detection areas 6 are a detection area 61 including a seat surface of one rear seat 42 and a detection area 62 including a seat surface of the other rear seat 42.

  4B and 4C show a second configuration example of the room lamp unit 81. In the second configuration example, the sensor devices 21 of the two sensor systems 2 are arranged side by side in the recess 813 on the lower surface of the unit main body 810. The two sensor devices 21 respectively correspond to the two rear seats 42 and transmit transmission waves toward the corresponding rear seats 42, respectively. Two light sources 812 are further arranged in the concave portion 813, and the two light sources 812 correspond to the two rear seats 42, respectively, and emit light toward the corresponding rear seats 42. The opening on the lower surface of the recess 813 is covered by the cover 811, and light, transmission waves, and reflected waves pass through the cover 811.

  The room lamp unit 82 is a front seat interior light, and is located above the seating surface of the front seat 41 and at the center of the width of the passenger compartment R1. FIG. 5 shows a configuration example of the room lamp unit 82. The room lamp unit 82 has a box-shaped unit main body 820 formed by resin molding or the like, and the unit main body 820 is attached to the ceiling 5. A translucent cover 821 is attached to the lower surface of the unit main body 820, and the light transmitted through the cover 821 illuminates the vicinity of the front seat 41. One sensor system 2 is attached to the left side of the unit main body 820.

  The sensor device 21 provided in the room lamp unit 82 corresponds to the front passenger seat 412, transmits a transmission wave toward the front passenger seat 412, and receives a reflected wave. In this case, a detection area 63 including the seat surface of the passenger seat 412 is formed as the detection area 6 by the sensor device 21 provided in the room lamp unit 82.

  As described above, in the present embodiment, among the driver's seat 411, the passenger seat 412, and the rear seat 42, the passenger seat 412 and the rear seat 42 are the target seats. Then, the sensor system 2 determines whether or not a person exists for each of the passenger seat 412 and the rear seat 42 that are the target seats. Note that all the seats (the driver seat 411, the passenger seat 412, and the rear seat 42) in the vehicle cabin R1 may be set as target seats.

  As shown in FIG. 3, the sensor device 21 includes a transceiver 21a, a transmission antenna 21b, a reception antenna 21c, and a dielectric lens 21d. The dielectric lens 21d covers at least the lower side and the side of the transmitting antenna 21b and the receiving antenna 21c.

  The transceiver 21a transmits a transmission wave from the transmission antenna 21b, and controls a frequency, a transmission timing, and the like of the transmission wave. The transmission wave transmitted from the transmission antenna 21b passes through the dielectric lens 21d and is radiated to the detection area 6. The transmission wave is preferably a quasi-millimeter wave having a frequency value of, for example, 10 GHz to 30 GHz. The transmission wave is preferably a quasi-millimeter wave having a frequency value of 24.15 GHz. The transmission wave is not limited to the quasi-millimeter wave, but may be a millimeter wave or a microwave. Further, the value of the frequency of the transmission wave is not particularly limited.

  The transmitted wave is reflected by the object 7 in the detection area 6, and the receiving antenna 21c receives the reflected wave transmitted through the dielectric lens 21d. The transmitter / receiver 21a outputs a sensor signal corresponding to the distance from the sensor device 21 to the object 7 when the reception intensity of the reflected wave is equal to or greater than a predetermined detection threshold. The sensor signal output from the sensor device 21 is an analog time-domain signal corresponding to the object 7. Note that the distance from the sensor device 21 to the object 7 corresponds to the distance from the antenna unit including the transmitting antenna 21b and the receiving antenna 21c to the object 7.

  The transceiver 21a uses, for example, an FMCW (Frequency-Modulated Continuous-Wave) method. The transceiver 21a transmits a transmission wave whose frequency (transmission frequency) changes over time from the transmission antenna 21b, and transmits a reflected wave whose frequency (reception frequency) changes over time to the reception antenna 21c. To receive through. Then, the transceiver 21a generates a beat signal having a frequency (beat frequency) equal to the frequency difference between the transmission frequency and the reception frequency. The signal processing device 22 receives a sensor signal (beat signal) from the sensor device 21 and can determine the distance to the object 7 based on the beat frequency.

Specifically, the transceiver 21a repeats a sweep process in which the frequency of the transmission wave (transmission frequency) is increased and then decreased. In the sweep processing, the transmission frequency increases by the sweep frequency width Δfa during the sweep time Ta. Assuming that the speed of light is C, the transmitter / receiver 21a receives the reflected wave 2 L / C after the transmission wave is transmitted. The frequency (reception frequency) of the reflected wave changes over time, similarly to the transmission frequency. Then, the transceiver 21a generates a beat signal having a frequency fb equal to the frequency difference between the transmission frequency and the reception frequency, and outputs it as a sensor signal. The frequency fb of the beat signal is fb = [(Δfa · 2L) / (C · T1)]. Therefore, the distance L to the human body 200 is expressed by equation (1).
L = (fb · C · T1) / (2 · Δfa) (1)

  In the present embodiment, it is preferable that the detection areas 61 and 62 are set so as to include the respective seating surfaces of the corresponding rear seats 42 and not include other seats. The detection area 63 is preferably set to include the seating surface of the passenger seat 412 and not include other seats. Furthermore, when the detection area 6 extends to the outside of the side door (including the side glass), a person, a vehicle, a plant, rain, and the like outside the vehicle may be erroneously detected as a person in the vehicle compartment R1. Therefore, it is preferable that the detection area 6 is set in the passenger compartment R1 and does not extend outside the passenger compartment R1. Therefore, the size, range, or shape of the detection area 6 is set in advance by the directivity of at least one of the transmitting antenna 21b and the receiving antenna 21c and the directivity of the dielectric lens 21d.

  FIG. 6 shows a configuration of the signal processing device 22. The signal processing device 22 includes a preprocessing unit 22a, a distance measurement unit 22b, a determination unit 22c, and an output unit 22d. FIG. 6 shows only one sensor system 2.

  Although the signal processing device 22 of the present embodiment is configured by one device, the signal processing device 22 may be configured by a plurality of devices. For example, the signal processing device 22 may include a first device, a second device, and a third device. In this case, the first device has a preprocessing unit 22a. The second device has a distance measuring unit 22b and a determining unit 22c. The third device has an output unit 22d. The first device, the second device, and the third device exchange signals with each other by wired communication (wired LAN, dedicated line communication) or wireless communication (wireless LAN, low-power wireless, etc.). When the signal processing device 22 includes a plurality of devices, the number of devices, the configuration of allocating each unit to each device, and the like are not limited to specific forms.

  The signal processing device 22 includes a computer system, and the computer system mainly includes a processor and a memory as hardware. When the processor executes the program recorded in the memory, at least each function of the distance measuring unit 22b and the determining unit 22c in the present embodiment is realized. The program may be pre-recorded in the memory of the computer system, or may be provided through an electric communication line, or may be stored in a non-transitory recording medium such as a memory card, optical disk, or hard disk drive that can be read by the computer system. It may be recorded and provided. A processor of a computer system includes one or more electronic circuits including a semiconductor integrated circuit (IC) or a large-scale integrated circuit (LSI). The plurality of electronic circuits may be integrated on one chip, or may be provided separately on a plurality of chips. The plurality of chips may be integrated in one device, or may be provided separately in a plurality of devices.

  The pre-processing unit 22a has an amplification unit and an A / D conversion unit. Specifically, the preprocessing unit 22a receives an analog time-domain sensor signal from the sensor device 21 and performs an amplification process of amplifying the sensor signal. The preprocessing unit 22a performs an A / D conversion process of converting the amplified analog sensor signal into a digital sensor signal and outputting the digital sensor signal. Further, it is preferable that the preprocessing unit 22a further has a function of removing a background signal from the sensor signal. The background signal includes, for example, a signal component due to a reflected wave from a seat and a noise component generated by on-vehicle equipment.

  The distance measuring unit 22b receives the sensor signal from the preprocessing unit 22a, and periodically (intermittently) measures the distance L based on the equation (1). That is, the distance measurement unit 22b periodically (intermittently) obtains the measured value of the distance L based on the equation (1), and sequentially outputs each data (discrete value data) of the plurality of periodically obtained measured values. Output. Note that the light speed C, the sweep time Ta, and the sweep frequency width Δfa are known, and the signal processing device 22 stores data of the light speed C, the sweep time Ta, and the sweep frequency width Δfa in advance.

  The determination unit 22c receives each data of a plurality of measurement values sequentially output from the distance measurement unit 22b. The determination unit 22c obtains a variation in the measured value of the distance L during the determination period T1 (predetermined period). The determination unit 22c determines whether or not the object 7 is a person based on the variation in the measured value of the distance L during the determination period T1. The determination unit 22c has a timer function, and the determination period T1 is set to a predetermined time length. The determination unit 22c sets the determination period T1 periodically. For example, the determination unit 22c preferably sets the time length of the determination period T1 to several seconds to about 10 seconds. 7A and 7B, a plurality of determination periods T1 are continuously set. In this case, if the second determination period T1 is set after the first determination period T1, the end timing of the first determination period T1 and the start timing of the second determination period T1 are the same.

  Note that the end timing of the first determination period T1 and the start timing of the second determination period T1 may be set at a predetermined time interval (for example, about 50 milliseconds). In this case, the plurality of determination periods T1 are set intermittently. Further, the start timing of the second determination period T1 may be set before the end timing of the first determination period T1. In this case, each of the plurality of determination periods T1 overlaps each part of the preceding and following determination periods T1.

  7A and 7B show measured values of the distance L obtained by the distance measuring unit 22b while the vehicle 9 is traveling. 7A is a measured value of the distance L when the object 7 is a person sitting on a seat. The measurement value P2 in FIG. 7B is a measurement value of the distance L when the object 7 is a cardboard box placed on a seat. Variations in the plurality of measured values P1 are mainly caused by the movement of the rib cage (movement of the rib cage in the front-back direction) due to human breathing. When the object 7 is a person, the person sitting on the seat continues to finely move by breathing or the like, but the fine movement of the person due to breathing is relatively stable, and the variation in the measured value P1 is relatively small. On the other hand, the dispersion of the plurality of measured values P2 is mainly caused by acceleration, vibration, and shaking of the vehicle 9, and the dispersion of the measured values P2 is relatively large. That is, the measured value P2 tends to have a larger variation than the measured value P1.

  Therefore, the determination unit 22c quantifies the variation of the measurement value for each determination period T1, and determines that the object 7 is a person if the variation of the plurality of measurement values is less than the threshold (a positive determination). The determination unit 22c determines that the object 7 is not a person if the variation of the plurality of measured values is equal to or larger than the threshold (negative determination). The determination unit 22c quantifies the variation of the measurement value for each determination period T1, for example, by calculating the variance or the standard deviation of the measurement value for each determination period T1. In this case, a threshold value is set for the variance or standard deviation of the measured value, and if the variance or standard deviation of the measured value in the determination period T1 is less than the threshold value, the determination result of the determination unit 22c for the determination period T1 is a positive determination. become. If the variance or the standard deviation of the measured values in the determination period T1 is equal to or greater than the threshold, the determination result of the determination unit 22c for the determination period T1 is negative.

  In addition, the determination unit 22c may quantify the variation in the measurement value for each determination period T1 by obtaining the difference between the maximum value and the minimum value of the measurement value for each determination period T1 as a variation width. In this case, a threshold value is set for the variation width of the measurement value, and if the variation width of the measurement value in the determination period T1 is less than the threshold value, the determination result of the determination unit 22c for the determination period T1 is a positive determination. If the fluctuation range of the measured value in the determination period T1 is equal to or greater than the threshold, the determination result of the determination unit 22c for the determination period T1 is negative.

  As described above, the determination unit 22c determines whether the object 7 is a person based on the variation in the measured value of the distance L during the determination period T1, and thereby determines whether the person sitting on the seat is on the seat or not. Objects other than humans can be distinguished. An object other than a person is, for example, a cardboard box, shopping bag, bag, or luggage.

  The output unit 22d generates a human detection signal based on the determination result of the determination unit 22c, and outputs the human detection signal to the notification system 3. The person detection signal is a signal for notifying the notification system 3 that a person is present in the detection area 6. In the present embodiment, the output unit 22d outputs a human detection signal when the determination result of the determination unit 22c is an affirmative determination continuously for a specified number of times or more. That is, when the determination result in each determination period T1 is an affirmative determination continuously for a specified number of times or more, the output unit 22d outputs a human detection signal. In this case, as the specified number of times increases, the sensitivity of the human detection decreases, and the frequency of the output unit 22d outputting the human detection signal decreases. When the specified number of times decreases, the sensitivity of human detection increases, and the frequency of the output unit 22d outputting the human detection signal increases.

  The output unit 22d starts outputting the human detection signal when the determination result switches from the negative determination to the positive determination. The output unit 22d continues to output the human detection signal until a predetermined period of time elapses after the determination result switches from the affirmative determination to the negative determination. Stop signal output.

  The output unit 22d may output the human detection signal only during a period in which the determination result is a positive determination.

  Next, the notification system 3 will be described in detail. The notification system 3 can receive a human detection signal from the signal processing device 22. The alerting system 3 outputs an alarm when a vehicle 9 travels and a person is present in the seat and a seatbelt non-wearing state occurs in which the state of the seatbelt of the seat is in a released state. Encourage wearing.

  As shown in FIG. 8, the notification system 3 includes a seat belt monitoring unit 3a, a controller 3b, and a notification unit 3c.

  The notification system 3 includes a computer system, and the computer system mainly includes a processor and a memory as hardware. When the processor executes the program stored in the memory, at least the functions of the seat belt monitoring unit 3a and the controller 3b in the present embodiment are realized. The program may be pre-recorded in the memory of the computer system, or may be provided through an electric communication line, or may be stored in a non-transitory recording medium such as a memory card, optical disk, or hard disk drive that can be read by the computer system. It may be recorded and provided. A processor of a computer system includes one or more electronic circuits including a semiconductor integrated circuit (IC) or a large-scale integrated circuit (LSI). The plurality of electronic circuits may be integrated on one chip, or may be provided separately on a plurality of chips. The plurality of chips may be integrated in one device, or may be provided separately in a plurality of devices. Further, the computer system of the signal processing device 22 and the computer system of the notification system 3 may be realized by one computer system.

  The seatbelt monitoring unit 3a receives a monitoring signal indicating the state of each seatbelt of the vehicle 9 via a vehicle-mounted network such as a CAN (Controller Area Network). Therefore, the seat belt monitoring unit 3a can monitor the state of each seat belt of the two rear seats 42 and the state of the seat belt of the front passenger seat 412. The state of the seat belt is a coupled state in which a person is wearing a seat belt, or a released state in which a person is not wearing a seat belt.

  The controller 3b detects the presence of a person (passenger seat 412 or rear seat) in which the presence of a person is detected while the vehicle 9 is traveling, based on the monitoring result of the seat belt monitoring unit 3a and the presence or absence of a person detection signal from the sensor system 2. It is determined whether or not the state of the seat belt in 42) is an unlocked state. The controller 3b causes the notification unit 3c to perform a notification operation when the state of the seat belt of the seat where the presence of a person is detected while the vehicle 9 is running is in the unlocked state. The controller 3b does not cause the notification unit 3c to perform the notification operation if the states of the seat belts of all the seats for which the presence of a person is detected while the vehicle 9 is traveling are in the coupled state. The controller 3b can determine whether or not the vehicle 9 is traveling by receiving a monitoring signal indicating the traveling state of the vehicle 9 via a vehicle-mounted network such as CAN.

  The notification unit 3c can perform a notification operation of outputting a notification sound into the vehicle cabin R1 according to an instruction from the controller 3b. At the time of executing the notification operation, the notification unit 3c uses the audio device or the navigation device provided in the vehicle compartment R1 to output a notification sound (buzzer sound or message) from a speaker provided in the vehicle compartment R1. Etc.). The notification sound is, for example, a buzzer sound or a message such as “Please wear a seat belt”.

  In addition, the notification unit 3c may individually output an alarm for each of the detection areas 61, 62, and 63. In this case, the plurality of sensor systems 2 are given unique identification information in advance. Then, each of the plurality of sensor systems 2 outputs a human detection signal to which identification information of the sensor system 2 is added. The notification unit 3c stores in advance the correspondence between each piece of identification information of the sensor system 2, each seat belt, the passenger seat 412, the rear seat 42, and the rear seat 42 (target seat). When the notification unit 3c receives the human detection signal to which the identification information is added from any of the sensor systems 2, if the state of the seat belt corresponding to the identification information is the released state, the notification unit 3c corresponds to the seat belt. An alarm sound is output for the seat. The notification sound is, for example, a message such as "Please wear the seat belt of the passenger seat 412". Therefore, when a person who does not wear a seatbelt is present in the passenger compartment R1, the notification system 3 prompts the user to wear the seatbelt by the notification operation of the notification unit 3c, thereby reducing the occurrence of the non-seatbelt state. be able to.

(Modification)
FIG. 9 shows a sensor system 2 of a modified example.

  The sensor system 2 of the modified example includes two sensor devices 21 and a signal processing device 22.

  The two sensor devices 21 each transmit a transmission wave, and at least a part of each area where each transmission wave reaches overlaps with each other. That is, one detection area 6 is formed by each detection area of the two sensor devices 21. When a part of each area where each transmission wave reaches overlaps with each other, one detection area 6 is a detection area of only one of the two sensor devices 21, a detection area of only the other of the two sensor devices 21, and 2 It consists of both detection areas of one sensor device 21. When the respective areas to which the transmission waves reach coincide, one detection area 6 is configured by only both detection areas of the two sensor devices 21.

  In the signal processing device 22, the pre-processing unit 22a (see FIG. 6) amplifies the respective sensor signals of the two sensor devices 21, converts them to digital sensor signals, and outputs the digital sensor signals. The distance measuring unit 22b (see FIG. 6) receives two sensor signals from the preprocessing unit 22a, and periodically (intermittently) measures the distance L for each of the two sensor signals based on Expression (1). . The determination unit 22c (see FIG. 6) obtains, for each of the two sensor signals, a variation in the measured value of the distance L during the determination period T1. The determination unit 22c determines whether the object 7 in the detection area 6 is a person based on each variation in the measured value of the distance L obtained for each of the two sensor signals. The output unit 22d (see FIG. 6) generates a human detection signal based on the determination result, and outputs the human detection signal to the notification system 3.

  Therefore, the signal processing device 22 can further improve the accuracy of human detection by using the sensor signals of the two sensor devices 21.

  Although the sensor system 2 has two sensor devices 21 in FIG. 9, the sensor system 2 may have three or more sensor devices 21.

  As described above, the signal processing device (22) of the first mode according to the embodiment includes the distance measurement unit (22b), the determination unit (22c), and the output unit (22d). The distance measuring unit (22b) intermittently measures the distance to the object (7) based on a sensor signal output by one or more sensor devices (21). The determination unit (22c) determines whether or not the object (7) is a person based on the variation of the measured values (P1 or P2) of the plurality of distances (L) during the determination period (T1) (predetermined period). I do. The output unit (22d) generates a human detection signal based on the determination result of the determination unit (22c) and outputs the human detection signal. Then, the determination unit (22c) makes an affirmative determination if the variation of the plurality of measurement values (P1 or P2) is less than the threshold, and makes a negative determination if the variation of the plurality of measurement values (P1 or P2) is equal to or greater than the threshold. .

  The above-described signal processing device (22) can distinguish a person sitting on the seat (41, 42) from an object other than the person on the seat (41, 42).

  Further, in the signal processing device (22) according to the second aspect according to the embodiment, in the first aspect, the determination unit (22c) determines the plurality of measurement values (P1 or P2) as a variation of the plurality of measurement values (P1 or P2). Preferably, the variance or standard deviation of P1 or P2) is determined.

  The above-described signal processing device (22) can quantify a variation in a plurality of measurement values (P1 or P2).

  Further, in the signal processing device (22) according to a third aspect according to the embodiment, in the first aspect, the determination unit (22c) determines a plurality of measurement values (P1 or P2) as a variation of the plurality of measurement values (P1 or P2). It is preferable to obtain the fluctuation range of P1 or P2).

  The above-described signal processing device (22) can quantify a variation in a plurality of measurement values (P1 or P2).

  Further, in the signal processing device (22) according to a fourth aspect according to the embodiment, in any one of the first to third aspects, the output unit (22d) is configured such that a determination result of the determination unit (22c) is defined. It is preferable to output a human detection signal in the case of an affirmative determination consecutively or more times.

  The signal processing device (22) described above can adjust the sensitivity of human detection by adjusting the specified number of times.

  Further, in the signal processing device (22) according to a fifth aspect according to the embodiment, in any one of the first to fourth aspects, the one or more sensor devices (21) each output a plurality of sensor signals. Preferably, there are a plurality of sensor devices (21) for outputting. The distance measuring unit (22b) intermittently measures a distance corresponding to each of the plurality of sensor signals. The determination unit (22c) determines whether or not the object (7) is a person based on the variation of the measured value (P1 or P2) of the distance (L) corresponding to each of the plurality of sensor signals.

  The signal processing device (22) described above can further improve the accuracy of human detection by using the sensor signals of the plurality of sensor devices (21).

  A sensor system (2) according to a sixth aspect according to the embodiment outputs a sensor signal that includes a sensor signal including information on a distance (L) to an object (7) in a detection area (6). 21) and the signal processing device (22) according to any one of the first to fifth aspects.

  The above-described sensor system (2) can distinguish a person sitting on the seat (41, 42) from an object other than the person on the seat (41, 42).

  The sensor system (2) according to a seventh aspect according to the embodiment is the sensor system (21) according to the sixth aspect, wherein the sensor device (21) transmits a radio wave as a transmission wave and transmits a radio wave reflected by the object (7) to a reflected wave. To generate a sensor signal.

  The above-mentioned sensor system (2) can distinguish a person sitting on the seat (41, 42) from an object other than a person on the seat (41, 42) using a radio wave sensor.

  The sensor system (2) according to an eighth aspect of the present invention is the sensor system (2) according to the sixth or the seventh aspect, wherein the plurality of seats (41, 42) provided in the cabin (R1) of the vehicle (9). One or more of the seats are the target seats. The detection area (6) is preferably a range including the target seat.

  The above-mentioned sensor system (2) distinguishes a person sitting on the seat (41, 42) of the vehicle (9) from an object other than a person on the seat (41, 42) using a radio wave sensor. can do.

  In the sensor system (2) according to a ninth aspect according to the embodiment, in the eighth aspect, the target seat is preferably a seat (412, 42) other than the driver's seat (411).

  The sensor system (2) described above uses a radio wave sensor to distinguish a person sitting on the seat (412, 42) of the vehicle (9) from an object other than a person on the seat (412, 42). can do.

  The sensor system (2) according to a tenth aspect according to the embodiment is the sensor system (21) according to the eighth or ninth aspect, wherein the sensor device (21) is a room lamp unit (8) on a ceiling (5) of a vehicle interior (R1). ) Is preferably provided.

  The above-mentioned sensor system (2) can improve the design.

  In the sensor system (2) according to an eleventh aspect according to the embodiment, in one of the sixth to tenth aspects, the one or more sensor devices (21) output a plurality of sensor signals, respectively. Preferably, there are a plurality of sensor devices (21).

  The above-described sensor system (2) can further improve the accuracy of human detection by using the sensor signals of the plurality of sensor devices (21).

  An alarm system (1) according to a twelfth aspect according to the present invention includes at least one sensor system (2) according to any one of the ninth to eleventh aspects and a human detection signal from the sensor system (2). And a notification system (3) for receiving the information. The notification system (3) has a seat belt monitoring unit (3a) and a notification unit (3c). The seatbelt monitoring unit (3a) monitors whether the state of the seatbelt of the target seat is an engaged state or a disengaged state. The notification unit (3c) outputs an alarm when receiving the human detection signal when the state of the seat belt of the target seat is in the disengaged state.

  The alarm system (1) described above can distinguish a person sitting on the seat (41, 42) from an object other than the person on the seat (41, 42). Further, the alarm system (1) can output an alarm when the non-wearing state of the seat belt occurs, and can prompt the user to wear the seat belt.

  In the thirteenth aspect of the alarm system (1) according to the embodiment, in the twelfth aspect, it is preferable that at least one sensor system (2) is a plurality of sensor systems (2). Each detection area (61, 62, 63) of the plurality of sensor systems (2) respectively corresponds to a plurality of target seats. The seatbelt monitoring unit (3a) monitors whether the state of each of the seatbelts of the plurality of target seats is a connected state or a disengaged state. The notification unit (3c) receives a human detection signal from the corresponding sensor system (2) for each detection area (61, 62, 63), and if the state of the seat belt of the corresponding target seat is the disengagement state. Then, an alarm corresponding to the detection area (61, 62, 63) is output.

  The above-mentioned alarm system (1) can detect the presence or absence of a person and the state of the seatbelt in each of the plurality of detection areas (61, 62, 63), and use the seatbelt for each seat in the passenger compartment (R1). Can be encouraged.

  A vehicle (9) according to a fourteenth aspect according to the embodiment includes the alarm system (1) according to the twelfth or thirteenth aspect, and a vehicle body (90) including the alarm system (1).

  The vehicle (9) described above can distinguish between a person sitting on the seat (41, 42) and an object other than the person on the seat (41, 42).

9 vehicle R1 cabin L distance T1 judgment period (predetermined period)
P1, P2 Measurement value 1 Alarm system 2 Sensor system 21 Sensor device 22 Signal processing device 22b Distance measurement unit 22c Judgment unit 22d Output unit 3 Notification system 3a Seat belt monitoring unit 3c Notification unit 41 Front seat (seat)
411 Driver's seat (seat)
412 Passenger seat (seat)
42 Backseat (seat)
5 Ceiling 6 (61, 62, 63) Detection area 7 Object 8 (81, 82) Room lamp unit 90 Vehicle body

Claims (14)

A distance measuring unit that intermittently measures a distance to an object based on a sensor signal output by one or more sensor devices;
A determination unit that determines whether the object is a person based on a variation in the plurality of distance measurement values in a predetermined period,
An output unit that generates a human detection signal based on the determination result of the determination unit and outputs the human detection signal,
The signal processing device, wherein the determination unit makes an affirmative determination if the variation in the plurality of measurement values is less than a threshold, and makes a negative determination if the variation in the plurality of measurement values is equal to or greater than the threshold. The signal processing device according to claim 1, wherein the determination unit obtains a variance or a standard deviation of the plurality of measurement values as a variation of the plurality of measurement values. The signal processing device according to claim 1, wherein the determination unit obtains a variation width of the plurality of measurement values as a variation of the plurality of measurement values. The signal processing device according to any one of claims 1 to 3, wherein the output unit outputs the human detection signal when a result of the determination by the determination unit is the positive determination continuously for a specified number of times or more. The one or more sensor devices are a plurality of sensor devices each outputting a plurality of sensor signals,
The distance measuring unit intermittently measures the distance corresponding to each of the plurality of sensor signals,
5. The signal according to claim 1, wherein the determination unit determines whether the object is a person based on variation in the measured value of the distance corresponding to each of the plurality of sensor signals. 6. Processing equipment. One or more sensor devices that output a sensor signal including information about a distance to an object in the detection area;
A sensor system, comprising: the signal processing device according to claim 1. The sensor system according to claim 6, wherein the sensor device transmits the radio wave as a transmission wave, and receives the radio wave reflected by the object as a reflected wave to generate the sensor signal. One or more seats among a plurality of seats provided in a vehicle cabin are set as target seats,
The sensor system according to claim 6, wherein the detection area is a range including the target seat. The sensor system according to claim 8, wherein the target seat is a seat other than a driver's seat. The sensor system according to claim 8, wherein the sensor device is provided in a room lamp unit on a ceiling of the passenger compartment. The sensor system according to any one of claims 6 to 10, wherein the one or more sensor devices are a plurality of sensor devices each outputting a plurality of sensor signals. At least one sensor system according to any one of claims 9 to 11,
A notification system that receives the human detection signal from the sensor system,
The notification system,
A seatbelt monitoring unit that monitors whether the state of the seatbelt of the target seat is in a coupled state or a disengaged state,
A notification unit that outputs a warning when the human detection signal is received when the state of the seat belt of the target seat is the disengagement state. The at least one sensor system is a plurality of sensor systems;
Each detection area of the plurality of sensor systems respectively corresponds to a plurality of the target seats,
The seatbelt monitoring unit monitors whether the state of each seatbelt of the plurality of target seats is the coupled state or the disengaged state,
The notification unit receives the human detection signal from the corresponding sensor system for each of the detection areas, and corresponds to the detection area if the state of the seat belt of the corresponding target seat is the disengagement state. The alarm system according to claim 12, which outputs an alarm. An alarm system according to claim 12 or 13,
A vehicle body including the alarm system.

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