JP6315584B2 - Object detection system - Google Patents

Description

  The present invention relates to an object detection system, and more particularly to an object detection system that can reliably recognize an abnormality in an object detection device such as a laser radar device.

  2. Description of the Related Art Conventionally, in an inter-vehicle distance warning system using a radar, it has been proposed to switch the content of a display unit that displays an inter-vehicle distance or the like to an error display when a system abnormality occurs (see, for example, Patent Document 1) .

  However, for example, when the sensitivity of the light receiving element decreases due to dirt or deterioration over time and the detection accuracy of the object decreases, the system may not be able to detect the occurrence of an abnormality because it is not an obvious failure. In this case, since the error display is not performed, the driver cannot recognize the system abnormality.

  Therefore, conventionally, if the target cannot be detected for a predetermined time while the vehicle is traveling at a predetermined speed or more, whether the front surface of the laser radar device is dirty and cannot detect an object, or whether the target actually does not exist. In order to be able to determine, it has been proposed to display the duration of undetected target on a display (see, for example, Patent Document 2).

  However, it is difficult for the driver to confirm the display on the display while the vehicle is traveling. Conversely, if the display is confirmed on the display while the vehicle is traveling, there is a risk that the operation may be hindered and a danger may be caused. Further, in the invention described in Patent Document 2, the display of the duration time when the target is not detected is cleared when the speed of the vehicle becomes less than a predetermined speed.

Japanese Patent Laid-Open No. 11-53699 JP 2005-140696 A

  The present invention makes it possible to reliably recognize an abnormality in an object detection device such as a laser radar device.

An object detection system according to the present invention includes an object detection device that detects an object in front of a vehicle and a notification unit that notifies an occupant based on a detection result of the object detection device. If the object is not detected, when the vehicle is parked, the object is notified that it has not been detected, when the vehicle is traveling, nothing comprise a notification control unit that controls not to notify.

In the object detection system of the present invention, when an object is not detected by the object detection apparatus, when the vehicle is parked, the object is notified that it has not been detected, when the vehicle is traveling, nothing is notified .

Therefore, it is possible to reliably recognize the abnormality of the object detection device. In addition, the driver's attention can be prevented from being distracted by unnecessary notifications.

  The object detection device includes, for example, a laser radar device, a millimeter wave radar device, an object detection device using an image sensor, and the like. The notification unit includes, for example, a display device such as a display provided in a car navigation system or an instrument panel, a light emitting device such as an LED (Light Emitting Diode), a sound output device such as a buzzer, and the like. The notification control unit includes, for example, a computing device such as a microcomputer and various processors.

The notification control unit, if the object is not detected by the object detection device, the vehicle is when the vehicle is stopped, it is possible to control so as to explicitly notify that an object is not detected.

  As a result, it is possible to reliably recognize that no object has been detected.

The notification to the control unit, if the object is detected by the object detection apparatus, when the vehicle is parked, it is possible to control so as to notify the position of the detected object.

  Accordingly, the driver can reliably recognize the abnormality of the object detection device by comparing the detection position of the object with the actual position of the object.

  This notification control unit can be provided in the object detection device.

  This notification control unit can be provided in the notification unit.

  According to the present invention, it is possible to reliably recognize an abnormality in an object detection device.

It is a block diagram which shows one Embodiment of the vehicle-mounted system to which this invention is applied. It is a block diagram which shows the structural example of a measurement light projector. It is a block diagram which shows the structural example of a light-receiving part. It is a figure which shows the position of each detection area typically. It is a schematic diagram which shows the relationship between each light receiving element and each detection area. It is a block diagram which shows the structural example of a measurement part. It is a block diagram which shows the structural example of the function of a calculating part. It is a flowchart for demonstrating a monitoring process. It is a figure for demonstrating the example of the detection method of a vehicle. It is a figure which shows the 1st example of the display screen of an object detection result. It is a figure which shows the 2nd example of the display screen of the detection result of an object. It is a figure which shows the 3rd example of the display screen of an object detection result. It is the table | surface which put together the operation | movement of the vehicle-mounted system with respect to the combination of the detection result of an object, and a vehicle speed. It is a figure which shows the 4th example of the display screen of an object detection result. It is a figure which shows the 5th example of the display screen of an object detection result. It is a figure which shows the 6th example of the display screen of the detection result of an object. It is a figure which shows the 7th example of the display screen of an object detection result. It is a figure which shows the 8th example of the display screen of the detection result of an object. It is a block diagram which shows the structural example of a computer.

Hereinafter, modes for carrying out the present invention (hereinafter referred to as embodiments) will be described. The description will be given in the following order.
1. Embodiment 2. FIG. Modified example

<1. Embodiment>
{Configuration example of in-vehicle system 1}
FIG. 1 shows a configuration example of an in-vehicle system 1 that is an embodiment of an in-vehicle system to which the present invention is applied.

  The in-vehicle system 1 is configured to include a laser radar device 11, a vehicle control unit 12, a notification unit 13, and a sensor unit 14.

  The laser radar device 11 monitors the front of the vehicle on which the in-vehicle system 1 is provided. Further, the laser radar device 11 controls the vehicle control unit 12 and the notification unit 13 based on the monitoring result in front of the vehicle.

  Hereinafter, an area in which an object can be detected by the laser radar device 11 is referred to as a monitoring area. Hereinafter, when it is necessary to distinguish a vehicle provided with the laser radar device 11 from other vehicles, the vehicle is referred to as a host vehicle. Further, hereinafter, a direction parallel to the left-right direction (vehicle width direction) of the host vehicle is referred to as a horizontal direction.

  The vehicle control unit 12 is configured by, for example, an ECU (Electronic Control Unit) or the like, and performs traveling control of the host vehicle.

  The notification unit 13 includes, for example, a display device such as a display provided in a car navigation system or an instrument panel, a light emitting device such as an LED (Light Emitting Diode), an audio output device such as a buzzer, or the like. For example, the notification unit 13 notifies the driver of the host vehicle of the monitoring result of the laser radar device 11 or issues an alarm for calling attention.

  The sensor part 14 is comprised by the various sensors provided in the own vehicle, such as a vehicle speed sensor and a steering angle sensor, for example. The sensor unit 14 supplies a sensor signal indicating the detection result of each sensor to the calculation unit 25 of the laser radar device 11.

  The laser radar device 11 is configured to include a control unit 21, a measurement light projecting unit 22, a light receiving unit 23, a measurement unit 24, and a calculation unit 25.

  The control unit 21 controls each unit of the laser radar device 11 based on commands and information from the vehicle control unit 12.

  The measurement light projector 22 projects measurement light, which is pulsed laser light (laser pulse) used to detect an object, onto the monitoring area.

  The light receiving unit 23 receives the reflected light of the measurement light and detects the intensity (brightness) of the reflected light from different directions in the horizontal direction. And the light-receiving part 23 outputs the some light reception signal which is an electrical signal according to the intensity | strength of the reflected light of each direction.

  The measurement unit 24 measures the light reception value for the reflected light from the light receiving unit 23 based on the analog light reception signal supplied from the light receiving unit 23, and supplies the digital light reception signal indicating the measured light reception value to the calculation unit 25. To do.

  The calculation unit 25 detects an object in the monitoring area based on the light reception signal supplied from the measurement unit 24. In addition, the calculation unit 25 detects the detected collision risk to the object and the predicted time (collision predicted time) until the object collides. The calculation unit 25 supplies the detection result to the control unit 21. Further, the calculation unit 25 instructs the vehicle control unit 12 to operate the automatic brake based on the detection result of the object and the speed of the host vehicle detected by the sensor unit 14, and detects the object to the notification unit 13. Command the display of results or the execution of alarms to the driver.

{Configuration example of measuring light projector 22}
FIG. 2 shows a configuration example of the measurement light projector 22 of the laser radar device 11. The measuring light projecting unit 22 is configured to include a drive circuit 101, a light emitting element 102, and a projecting optical system 103.

  The drive circuit 101 controls the light emission intensity and the light emission timing of the light emitting element 102 under the control of the control unit 21.

  The light emitting element 102 is made of, for example, a laser diode, and emits measurement light (laser pulse) under the control of the drive circuit 101. The measurement light emitted from the light emitting element 102 is projected onto the monitoring area via the light projecting optical system 103 constituted by a lens or the like.

{Configuration example of light receiving unit 23}
FIG. 3 shows a configuration example of the light receiving unit 23 of the laser radar device 11. The light receiving unit 23 is configured to include a light receiving optical system 201 and light receiving elements 202-1 to 202-16.

  Hereinafter, the light receiving elements 202-1 to 202-16 are simply referred to as the light receiving elements 202 when it is not necessary to distinguish them individually.

  The light receiving optical system 201 is configured by a lens or the like, and is installed so that the optical axis faces the front-rear direction of the vehicle. The light receiving optical system 201 receives the reflected light of the measurement light reflected by an object or the like in the monitoring area, and makes the reflected light incident on the light receiving surface of each light receiving element 202.

  Each light receiving element 202 is composed of, for example, a photodiode that photoelectrically converts incident photoelectric charges into a received light signal having a current value corresponding to the amount of light. Each light receiving element 202 is perpendicular to the optical axis of the light receiving optical system 201 and parallel to the vehicle width direction of the host vehicle (that is, horizontal) at the position where the reflected light incident on the light receiving optical system 201 is collected. In the direction). Then, the reflected light incident on the light receiving optical system 201 is distributed and incident on each light receiving element 202 according to the incident angle in the horizontal direction to the light receiving optical system 201. Therefore, each light receiving element 202 receives reflected light from different directions in the horizontal direction among the reflected light from the monitoring region. Thereby, the monitoring area is divided into a plurality of areas (hereinafter referred to as detection areas) in a plurality of horizontal directions, and each light receiving element 202 individually receives the reflected light from the corresponding detection area. The light receiving element 202 photoelectrically converts the received reflected light into a light reception signal having a current value corresponding to the amount of light received, and supplies the obtained light reception signal to the measurement unit 24.

  Here, a specific example of the detection region of each light receiving element 202 will be described with reference to FIGS. 4 and 5. FIG. 4 schematically shows the position of each detection region when the host vehicle C provided with the laser radar device 11 is viewed from above. FIG. 5 schematically shows the relationship between each light receiving element 202 and each detection region when the light receiving unit 23 is viewed from above. In FIG. 5, only the light rays passing through the center of the lens of the light receiving optical system 201 out of the reflected light from each detection region are schematically shown for easy understanding of the drawing.

  The light receiving elements 202 are arranged in a line in the order of the light receiving elements 202-1, 202-2, 202-3... From the right in the traveling direction of the host vehicle C. On the other hand, the monitoring area of the laser radar device 11 is composed of detection areas A1 to A16 that radiate in front of the host vehicle C, and each detection area is a detection area from the left in the traveling direction of the host vehicle C. A1, A2, A3... Are arranged in this order. For example, the light receiving element 202-1 receives reflected light from the detection area A1 which is the left end in the monitoring area and indicated by the oblique line in front of the left side of the host vehicle C. The light receiving element 202-16 receives reflected light from the detection area A16, which is the right end in the monitoring area and indicated by the oblique line in front of the right side of the host vehicle C. Furthermore, the light receiving elements 202-8 and 202-9 receive the reflected light from the detection areas A8 and A9 indicated by the hatching in the center of the monitoring area.

{Configuration example of measurement unit 24}
FIG. 6 shows a configuration example of the measurement unit 24 of the laser radar device 11. The measurement unit 24 is configured to include a current / voltage conversion unit 251, an amplification unit 252, and a sampling unit 253. The current-voltage converter 251 is configured to include trans-impedance amplifiers (TIAs) 261-1 to 261-16. The amplifying unit 252 is configured to include programmable gain amplifiers (PGA) 262-1 to 262-16. The sampling unit 253 is configured to include A / D converters (ADC) 263-1 to 263-16. In addition, the TIA 261-i, the PGA 262-i, and the ADC 263-i (i = 1 to 16) are connected in series.

  Hereinafter, when it is not necessary to individually distinguish TIA 261-1 through 261-16, PGA 262-1 through 262-16, and ADC 263-1 through 263-16, TIA 261, PGA 262, and ADC 263 are simply Called.

  Each TIA 261 performs current-voltage conversion of the light reception signal supplied from the light receiving element 202 under the control of the control unit 21. That is, each TIA 261 converts a received light signal as an input current into a received light signal as a voltage, and amplifies the voltage of the converted received light signal with a gain set by the control unit 21. Each TIA 261 supplies the amplified received light signal to the subsequent PGA 262.

  Under the control of the control unit 21, each PGA 262 amplifies the voltage of the light reception signal supplied from the TIA 261 with the gain set by the control unit 21, and supplies the amplified signal to the subsequent ADC 263.

  Each ADC 263 performs A / D conversion of the received light signal. That is, each ADC 263 performs measurement of a light reception value at each sampling time by sampling an analog light reception signal supplied from the PGA 262 at a predetermined sampling interval under the control of the control unit 21. Each ADC 263 supplies a digital light reception signal indicating a sampling result (measurement result) of the light reception value to the arithmetic unit 25.

{Configuration example of calculation unit 25}
FIG. 7 shows a configuration example of the function of the calculation unit 25. The calculation unit 25 is configured to include a detection unit 301 and a command unit 302.

  The detection unit 301 detects an object in the monitoring area. The detection unit 301 is configured to include a peak detection unit 311 and an object detection unit 312.

  As will be described later, the peak detection unit 311 detects the peak of the light reception value of each light receiving element 202 based on the light reception signal supplied from each ADC 263. Thereby, the peak of the intensity | strength of the reflected light of measurement light in the horizontal direction and the time direction (distance direction) is detected. The peak detection unit 311 supplies the detection result to the object detection unit 312.

  The object detection unit 312 detects an object in the monitoring area based on the horizontal direction and time direction (distance direction) distribution of the received light value (reflected light intensity) and the peak detection result. Further, the object detection unit 312 is based on the speed and steering angle of the host vehicle detected by the sensor unit 14, and the collision risk to the detected object and the predicted time until the object collides (collision prediction time). Is detected. The object detection unit 312 supplies the detection result to the control unit 21 and the command unit 302.

  The command unit 302 commands the vehicle control unit 12 and the notification unit 13 based on the detection result of the object by the object detection unit 312 and the speed of the host vehicle detected by the sensor unit 14. The command unit 302 is configured to include a brake control unit 321 and a notification control unit 322.

  The brake control unit 321 determines whether to activate the automatic brake based on the detection result of the object by the object detection unit 312 and the speed of the host vehicle detected by the sensor unit 14. When it is determined that the automatic brake is to be operated, the brake control unit 321 instructs the vehicle control unit 12 to operate the automatic brake.

  Whether the notification control unit 322 displays the detection result of the object or issues a warning to the driver based on the detection result of the object by the object detection unit 312 and the speed of the host vehicle detected by the sensor unit 14. Determine. When the notification control unit 322 determines to display the detection result of the object or to issue an alarm to the driver, the notification control unit 322 instructs the notification unit 13 to display the detection result of the object or to execute the alarm to the driver.

{Monitoring process}
Next, the monitoring process executed by the in-vehicle system 1 will be described with reference to the flowchart of FIG. Hereinafter, the speed of the host vehicle is referred to as a vehicle speed V.

  In step S <b> 1, the control unit 21 determines whether the engine of the host vehicle has started based on information from the vehicle control unit 12. This determination process is repeatedly executed until it is determined that the engine is started. When it is determined that the engine is started, the process proceeds to step S2.

  In step S2, the laser radar device 11 detects an object. Specifically, the drive circuit 101 emits pulsed measurement light from the light emitting element 102 under the control of the control unit 21. The measurement light emitted from the light emitting element 102 is projected onto the entire monitoring region via the light projecting optical system 103.

  Each light receiving element 202 receives the reflected light from the detection region in the corresponding direction among the reflected light with respect to the measuring light projected from the measuring light projecting unit 22 via the light receiving optical system 201. Each light receiving element 202 photoelectrically converts the received reflected light into a received light signal that is an electrical signal corresponding to the received light amount, and supplies the obtained received light signal to the TIA 261 at the subsequent stage.

  Each TIA 261 performs current-voltage conversion of the light reception signal supplied from each light receiving element 202 under the control of the control unit 21 and amplifies the voltage of the light reception signal by the gain set by the control unit 21. Each TIA 261 supplies the amplified light reception signal to the subsequent PGA 262.

  Under the control of the control unit 21, each PGA 262 amplifies the voltage of the light reception signal supplied from each TIA 261 with the gain set by the control unit 21, and supplies the amplified signal to the subsequent ADC 263.

  Each ADC 263 performs sampling of the light reception signal supplied from each PGA 262 under the control of the control unit 21, and A / D converts the light reception signal. Each ADC 263 supplies a digital light reception signal indicating a sampling value (light reception value) at each sampling time to the peak detection unit 311.

  Here, for example, if the sampling frequency of the ADC 263 is 600 MHz, sampling is performed at a sampling interval of about 1.67 nanoseconds. Therefore, the received light value is sampled at intervals of about 250 mm in terms of distance. That is, the intensity of the reflected light from each point at intervals of about 250 mm in the distance direction from the host vehicle in each detection region is measured. For example, when the sampling frequency of the ADC 263 is 6 GHz, sampling is performed at a sampling interval of about 0.167 nanoseconds. Therefore, the received light value is sampled at intervals of about 25 mm in terms of distance. That is, the intensity of the reflected light from each point at an interval of about 25 mm in the distance direction from the host vehicle in each detection region is measured.

  The peak detector 311 detects a sampling time at which the light reception value reaches a peak for each light receiving element 202. That is, the peak detector 311 detects the peak in the time direction of the received light value for each horizontal detection region corresponding to each light receiving element 202. Thereby, the position where the intensity of reflected light peaks in the distance direction from the host vehicle is detected for each detection region in the horizontal direction. That is, the distance from the host vehicle at a position where there is a high possibility that an object that reflects the measurement light exists in each detection region is detected.

  At this time, the light receiving element 202 (detection region) in which the light reception value peaks at every sampling time may be further detected. That is, the horizontal peak of the light reception value at each sampling time may be detected. Thereby, in the distance direction from the host vehicle, a horizontal position (detection region) where the intensity of the reflected light peaks at every predetermined interval (for example, about every 25 to 250 mm) is detected.

  Then, the peak detection unit 311 supplies the detection result to the object detection unit 312.

  The object detection unit 312 detects other objects such as other vehicles, pedestrians, and road accessories in the monitoring area based on the horizontal and temporal distributions of the received light values (that is, the intensity of the reflected light) and the peak detection results. The presence / absence of the object, the type, direction, and distance of the object are detected. The object detection unit 312 predicts the traveling direction of the host vehicle based on, for example, the speed and steering angle of the host vehicle detected by the sensor unit 14. And the object detection part 312 determines whether there exists a danger of colliding with the detected object based on the result of having predicted the advancing direction of the own vehicle. Furthermore, when there is a risk of collision with the detected object, the object detection unit 312 predicts the time until the object collides based on the speed of the host vehicle. Then, the object detection unit 312 supplies the command detection unit 302 with the detection result of the object including the collision risk and the predicted collision time.

  Note that any method can be employed as the object detection method of the object detection unit 312.

  Here, an example of the object detection method will be described with reference to FIG.

  The graph of FIG. 9 shows the horizontal distribution of the received light value at the sampling time near the reflected light from the vehicle 351 when the vehicle 351 is traveling in front of the host vehicle. That is, this graph is a graph in which the light reception values of the respective light receiving elements 202 at the sampling time are arranged in the horizontal axis direction in the horizontal arrangement order of the respective light receiving elements 202.

  The measurement light is reflected by the vehicle 351 and received by the light receiving element 202, but there is a time difference from light projection to light reception. Since this time difference is proportional to the distance between the laser radar device 11 and the vehicle 351, the reflected light from the vehicle 351 is measured as a light reception value at a sampling timing (sampling time tn) that matches the time difference. Accordingly, among the light reception values of the respective light receiving elements 202 in the detection region including the vehicle 351, the light reception value particularly at the sampling time tn is increased.

  Further, when the vehicle 351 is present in the front, the reflected light reflected by the vehicle 351 is received by the light receiving element 202, so that the light receiving value of each light receiving element 202 including the vehicle 351 in the detection region becomes large. In particular, since the reflectance of the left and right reflectors 352L and 352R behind the vehicle 351 is high, the light reception value of each light receiving element 202 including the reflectors 352L and 352R in the detection region is particularly large.

  Therefore, as shown in the graph of FIG. 9, two prominent peaks P11 and P12 appear in the distribution of received light values in the horizontal direction. In addition, since the reflected light reflected by the vehicle body between the reflectors 352L and 352R is also detected, the light reception value between the peak P11 and the peak P12 is higher than that in other regions. Thus, it is possible to detect the vehicle ahead by detecting two prominent peaks in the horizontal distribution of the received light values at the same sampling time.

  In step S3, the command unit 302 determines whether an object has been detected. If it is determined that an object has been detected, the process proceeds to step S4.

  In step S4, command unit 302 determines whether vehicle speed V is 10 km / h or less. When it is determined that the vehicle speed V is 10 km / h or less, the process proceeds to step S5.

  In step S5, the command unit 302 determines whether or not the vehicle speed V is 0 km / h. If it is determined that the vehicle speed V is 0 km / h, the process proceeds to step S6. This is a case where an object is detected forward while the host vehicle is stopped.

  In step S6, the in-vehicle system 1 displays the position of the detected object. Specifically, the notification control unit 322 supplies a signal that includes the detection result of the object and commands the display of the detection result of the object to the notification unit 13. The notification unit 13 displays the detection result of the object by the laser radar device 11 in accordance with a command from the notification control unit 322.

  Thereafter, the process proceeds to step S14.

  FIG. 10 shows an example of the display screen displayed at this time. Here, a display example on the display 404 between the speed meter 402 and the tachometer 403 of the instrument panel 401 of the host vehicle is shown. Note that the lower screen in FIG. 10 is an enlarged view of the screen displayed on the display 404.

  In this example, a vehicle 411 representing the position of the host vehicle on this display screen is displayed at the approximate center in the left-right direction below the screen. The vehicle 411 is always displayed at the same position on the display screen. Further, an area 412 that extends radially above the vehicle 411 is displayed. This area 412 schematically shows a monitoring area of the laser radar device 11. Further, a road 413 is displayed above the vehicle 411. A road 413 schematically represents that a road is detected in front of the host vehicle. Accordingly, the road 413 is not displayed when a road cannot be detected in front of the host vehicle while traveling on a gravel road or the like.

  In addition, circular icons T1 and T2 representing the position of the detected object are displayed in the area 412. Therefore, here, an example in which two objects are detected in the monitoring area is shown. The position of each icon moves depending on the position of the object. Specifically, the position of the icon moves in the left-right direction on the display screen depending on the detection region where the object is detected, that is, the horizontal position where the object is detected. Further, the position of the icon moves in the vertical direction of the display screen depending on the detected distance to the object. Further, the icons T1 and T2 are given different colors so that they can be easily identified. Note that the icon T1 and the icon T2 may be identified from a pattern, a shape, or the like.

  The driver can intuitively recognize the position of the object detected in front of the host vehicle by using the icons T1 and T2.

  In addition, information about the detected object is displayed in an information area 414 surrounded by a dotted line on the right side of the vehicle 411. A dotted line surrounding the information area 414 is an auxiliary line indicating the range of the information area 414 and is not displayed on the actual screen.

  In this example, the distance to the object represented by the icons T1 and T2 is displayed. Here, for example, the color of the character displaying the distance to each object is set to the same color as the icon corresponding to each object. Thereby, when a plurality of objects are detected, the distance to each object can be easily recognized. When a slope is detected in front of the host vehicle, the distance to the slope is displayed as “Hill road xx m”.

  On the other hand, if it is determined in step S5 that the vehicle speed V is not 0 km / h, the process proceeds to step S7. This is a case in which an object is detected ahead while the host vehicle is traveling at 10 km / h or less.

  In step S7, the in-vehicle system 1 displays the detected position of the object and the predicted collision time. Specifically, the notification control unit 322 supplies a signal that includes the detection result of the object and commands the display of the detection result of the object to the notification unit 13. The notification unit 13 displays the detection result of the object by the laser radar device 11 in accordance with a command from the notification control unit 322.

  Thereafter, the process proceeds to step S14.

  FIG. 11 shows an example of the display screen displayed at this time. The display screen of FIG. 11 is substantially the same as the display screen of FIG. 10, but the display in the information area 414 is different. Specifically, FIG. 11 shows an example in which one object is detected and an icon T3 corresponding to the detected object is displayed. In the information area 414, in addition to the distance to the object represented by the icon T3, a predicted collision time for the object is displayed.

  On the other hand, if it is determined in step S4 that the vehicle speed V exceeds 10 km / h, the process proceeds to step S8.

  In step S8, the command unit 302 determines whether there is a risk of collision with an object. If it is determined that there is a risk of collision with the object, the process proceeds to step S9.

  In step S9, the command unit 302 determines whether or not the vehicle speed V is 30 km / h or less. If it is determined that the vehicle speed V is 30 km / h or less, the process proceeds to step S10. This is a case where an object that may collide is detected forward while the host vehicle is traveling at a low speed (10 km / h <vehicle speed V ≦ 30 km / h).

  In step S10, the in-vehicle system 1 operates an automatic brake. Specifically, the brake control unit 321 supplies a signal for commanding the operation of the automatic brake to the vehicle control unit 12. The vehicle control unit 12 operates the brake of the host vehicle in accordance with a command from the brake control unit 321. Thereby, it can avoid automatically that the own vehicle collides with the object ahead.

  Thereafter, the process proceeds to step S14.

  On the other hand, when it is determined in step S9 that the vehicle speed V exceeds 30 km / h, the process proceeds to step S11. This is a case where an object that may collide is detected forward while the host vehicle is traveling at a medium speed or higher (more than 30 km / h).

  In step S11, the in-vehicle system 1 issues an alarm. Specifically, the notification control unit 322 supplies the notification unit 13 with a signal that instructs execution of an alarm. The notification unit 13 issues a warning by a predetermined method in accordance with a command from the notification control unit 322, and alerts the driver to the object ahead. At this time, the alarm is issued in such a manner that the driver can easily notice while concentrating on driving. For example, the alarm is issued by a method such as a warning message by voice, a warning sound, lighting or blinking of light. In addition, since the warning by a display screen like FIG.10 and FIG.11 mentioned above cannot be confirmed if a driver | operator does not look aside, it is not performed here.

  Thereafter, the process proceeds to step S14.

  On the other hand, if it is determined in step S8 that there is no risk of colliding with the object, the processes in steps S9 to S11 are skipped, and the process proceeds to step S14. This is a case where an object without a risk of collision is detected forward while the host vehicle is traveling at a low speed or more (more than 10 km / h). In this case, neither an object detection result display nor an alarm to the driver is performed.

  On the other hand, if it is determined in step S3 that no object has been detected, the process proceeds to step S12.

  In step S12, the command unit 302 determines whether or not the vehicle speed V is 0 km / h. When it is determined that the vehicle speed V is 0 km / h, the process proceeds to step S13. This is a case where no object is detected ahead while the host vehicle is stopped.

  In step S13, the in-vehicle system 1 displays that no object is detected. Specifically, the notification control unit 322 supplies a signal that includes the detection result of the object and commands the display of the detection result of the object to the notification unit 13. The notification unit 13 displays the detection result of the object by the laser radar device 11 in accordance with a command from the notification control unit 322.

  Thereafter, the process proceeds to step S14.

  FIG. 12 shows an example of the display screen displayed at this time. The display screen of FIG. 12 is almost the same as the display screens of FIGS. 10 and 11, but no icon is displayed in the area 412 because no object is detected. Instead, a message 415 indicating that only roads are detected is displayed in the area 412. Note that the message 415 is not displayed when no road is detected in front of the host vehicle. In addition, in the information area 414, a message that explicitly indicates that an object that becomes an obstacle has not been detected is displayed.

  On the other hand, if it is determined in step S12 that the vehicle speed V is not 0 km / h, the process of step S13 is skipped, and the process proceeds to step S14. This is a case where no object is detected ahead while the host vehicle is traveling. In this case, neither an object detection result display nor an alarm to the driver is performed.

  In step S14, the control unit 21 determines whether or not the engine has stopped. If it is determined that the engine is not stopped, the process returns to step S2. Thereafter, the processes in steps S2 to S14 are repeatedly executed until it is determined in step S14 that the engine has stopped.

  On the other hand, if it is determined in step S14 that the engine has stopped, the monitoring process ends.

  FIG. 13 is a table summarizing the operation of the in-vehicle system 1 for the combination of the object detection result and the vehicle speed V in the monitoring process described above.

  When an object is detected ahead while the host vehicle is stopped (vehicle speed V = 0 km / h), the position of the object including the distance to the detected object is displayed. On the other hand, when an object is not detected ahead while the host vehicle is stopped (vehicle speed V = 0 km / h), it is explicitly displayed that the object is not detected.

  Since the driver cannot watch the display screen while the host vehicle is traveling, the driver cannot accurately recognize the content of the display screen. On the other hand, since the driver can watch the display screen while the host vehicle is stopped, the driver can accurately recognize the content of the display screen. Therefore, by displaying the detection result of the object by the laser radar device 11 while the host vehicle is stopped in this way, the driver can accurately recognize the detection result. In particular, by explicitly displaying that no object is detected, the driver can reliably recognize that no object is detected by the laser radar device 11.

  Then, the driver recognizes the detection result of the laser radar device 11 accurately, and compares the actual situation ahead of the host vehicle with the detection result, so that the laser radar device 11 is operating normally. Whether or not can be recognized easily and accurately. For example, the driver can recognize that the laser radar device 11 is operating normally when the displayed detection result and the actual situation in front of the host vehicle substantially coincide. On the other hand, for example, the driver does not display an object that exists in front of the host vehicle, displays an object that does not exist in front of the host vehicle, or the position of the displayed object is different from the actual position. In some cases, it can be recognized that an abnormality has occurred in the laser radar device 11. In particular, since the distance to the object is displayed as a specific numerical value as the position information of the object, the driver can easily recognize the difference between the detection result and the actual position of the object. As a result, the driver can surely recognize a decrease in sensitivity of the light receiving element 202 due to dirt, aging deterioration, or the like, which is difficult to detect by the laser radar device 11 itself, or an abnormality due to noise or the like.

  Further, when an object is detected ahead while the host vehicle is traveling slowly (0 km / h <vehicle speed V ≦ 10 km / h), the position of the object including the distance to the object and the predicted collision time are displayed. When the host vehicle is driving slowly, the driver can view the display screen for a short time, even if he cannot watch the display screen. Accordingly, the driver can easily grasp the position of the object in front of the host vehicle and the predicted collision time, and can quickly take action to avoid danger. In addition, as in the case where the host vehicle is stopped, the driver compares the actual situation ahead of the host vehicle with the detection result, thereby reducing the sensitivity of the light receiving element 202 due to dirt, aging, etc. The occurrence of an abnormality in the laser radar device 11 due to noise or the like can be reliably recognized.

  Further, when the subject vehicle is traveling at a low speed (10 km / h <vehicle speed V ≦ 30 km / h) and an object that is likely to collide is detected forward, the automatic brake is activated. Thereby, it can avoid automatically that the own vehicle collides with the object ahead. At this time, since the detection result of the object is not displayed, it is possible to prevent the driver's attention from being distracted by unnecessary display.

  Further, when an object that may collide while the host vehicle is traveling at a medium speed or higher (vehicle speed V> 30 km / h) is detected ahead, an alarm is issued to alert the driver. As a result, the driver can notice the object ahead more quickly and take action to avoid the collision. At this time, since the detection result of the object is not displayed, it is possible to prevent the driver's attention from being distracted by unnecessary display.

  Further, when the host vehicle is traveling at a low speed or higher (vehicle speed V> 10 km / h), an object that is not in danger of colliding is detected forward, and while the host vehicle is traveling, the object is detected forward. If not, neither display of the object detection result nor warning to the driver is performed. Thereby, it is possible to prevent the driver's attention from being distracted by unnecessary display and warning.

{Example of object detection result display screen}
Next, with reference to FIGS. 14 to 18, a display screen of the detection result of the object, particularly a display example of an icon representing the detected object will be described. In FIG. 14 to FIG. 18, the information area 414 is not shown.

  FIG. 14 is a display example when objects are detected at substantially the same distance in a plurality of adjacent detection areas. In this case, the icon T4 has a horizontally long shape as compared with the icons T1 to T3 in FIGS. As a result, the driver can intuitively recognize the width of the detected object.

  15 to 17 show examples of icons displayed on the display screen in the process of detecting the vehicle ahead.

  First, the reflected light from the reflectors near both ends of the rear part of the front vehicle is detected. Therefore, as shown in FIG. 15, icons T5 and T6 are displayed in an area 412 above the vehicle 411 so as to be arranged at intervals in the horizontal direction.

  Next, the reflected light from the vehicle body between the reflectors is detected. However, the intensity of the reflected light differs between the reflector and the vehicle body. That is, the reflected light from the reflector is strong and the reflected light from the vehicle body is weak. Therefore, by changing the color or pattern of the icon in accordance with the light reception value, an icon T7 having a horizontally long shape and distinguishing the reflector portion and the vehicle body portion as shown in FIG. 16 is displayed.

  Finally, when it is determined that the object ahead is a vehicle, a vehicle-type icon T8 is displayed as shown in FIG. Thus, the driver can intuitively recognize that the object ahead is a vehicle.

  When a plurality of vehicles are detected in front of the host vehicle, a vehicle type icon is displayed for each vehicle. For example, when two vehicles are detected in front of the host vehicle, vehicle type icons T9 and T10 are displayed as shown in FIG.

<2. Modification>
Hereinafter, modifications of the above-described embodiment of the present invention will be described.

{Modification of the configuration of the laser radar device}
The configuration of the laser radar apparatus is not limited to the example shown in FIG. 1, and can be changed as necessary.

  For example, it is possible to integrate the control unit 21 and the calculation unit 25 or to change the sharing of functions.

  In the above description, an example in which the operation of automatic braking is instructed from the laser radar device 11 to the vehicle control unit 12 has been described. However, an object detection result is supplied from the laser radar device 11 to the vehicle control unit 12. Also good. Then, the vehicle control unit 12 may determine and execute whether or not to activate the automatic brake based on the detection result of the object, the vehicle speed V, and the like.

  Further, in the above description, an example in which the laser radar device 11 instructs the notification unit 13 to display an object detection result or to execute an alarm is shown. However, the laser radar device 11 supplies the object detection result to the notification unit 13. You may make it do. Then, the notification unit 13 may determine whether or not to display the detection result of the object and whether or not to execute the alarm based on the detection result of the object, the vehicle speed V, or the like, or may set the display content. Good. In this case, for example, the notification control unit 322 is provided in the notification unit 13.

  Further, for example, the number of light receiving elements 202, TIA 261, PGA 262, and ADC 263 can be increased or decreased as necessary.

{Variation of notification method of object detection result}
The display example of the object detection result described above with reference to FIGS. 10 to 12 and FIGS. 14 to 18 is an example, and the object detection result can be freely changed within a recognizable range. is there.

  Further, the object detection result is not necessarily notified using an image, and may be notified, for example, by a message by characters, lighting or blinking of a lamp, or the like. In particular, when notifying that an object has not been detected, it is not necessary to notify the position of the object, and for example, notification can be easily performed without using an image.

  Furthermore, for example, besides the visual method, the detection result of the object may be notified by an auditory method such as a warning sound or a voice message.

{About the scope of application of the present invention}
In addition to the examples described above, the present invention is applied to an apparatus or system that is provided in a vehicle, projects measurement light in a predetermined monitoring direction, and detects an object based on the intensity of reflected light of the measurement light. Can do.

  For example, the present invention receives not only a laser radar device that simultaneously projects measurement light in the monitoring direction and simultaneously receives reflected light by a plurality of light receiving elements, but also receives reflected light while scanning the laser light in the horizontal direction. The present invention can also be applied to the case of using a laser radar device of the type.

  The present invention can also be applied to the case where a radar apparatus using measurement light other than laser, millimeter wave, or the like is used.

  Furthermore, the present invention can also be applied to the case of using an object detection device other than the radar device, such as an object detection device that detects an object using an image sensor.

  The object detection method is not limited to the above-described example, and an arbitrary method can be adopted.

  Furthermore, the type of vehicle to which the present invention is applied is not particularly limited. For example, the present invention can be applied to vehicles such as motorcycles, three-wheel trucks, small trucks, small passenger cars, large passenger cars, large buses, large trucks, large special vehicles, and small special vehicles. When applied to a vehicle using a prime mover such as a motor other than the engine, whether the prime mover has been started or stopped is determined in steps S1 and S14 of FIG. 8 described above.

{Example of computer configuration}
The series of processes described above can be executed by hardware or can be executed by software. When a series of processing is executed by software, a program constituting the software is installed in the computer. Here, the computer includes, for example, a general-purpose personal computer capable of executing various functions by installing various programs by installing a computer incorporated in dedicated hardware.

  FIG. 19 is a block diagram illustrating an example of a hardware configuration of a computer that executes the series of processes described above according to a program.

  In a computer, a CPU (Central Processing Unit) 601, a ROM (Read Only Memory) 602, and a RAM (Random Access Memory) 603 are connected to each other by a bus 604.

  An input / output interface 605 is further connected to the bus 604. An input unit 606, an output unit 607, a storage unit 608, a communication unit 609, and a drive 610 are connected to the input / output interface 605.

  The input unit 606 includes a keyboard, a mouse, a microphone, and the like. The output unit 607 includes a display, a speaker, and the like. The storage unit 608 includes a hard disk, a nonvolatile memory, and the like. The communication unit 609 includes a network interface or the like. The drive 610 drives a removable medium 611 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory.

  In the computer configured as described above, the CPU 601 loads the program stored in the storage unit 608 to the RAM 603 via the input / output interface 605 and the bus 604 and executes the program, for example. Is performed.

  The program executed by the computer (CPU 601) can be provided by being recorded on a removable medium 611 as a package medium, for example. The program can be provided via a wired or wireless transmission medium such as a local area network, the Internet, or digital satellite broadcasting.

  In the computer, the program can be installed in the storage unit 608 via the input / output interface 605 by attaching the removable medium 611 to the drive 610. Further, the program can be received by the communication unit 609 via a wired or wireless transmission medium and installed in the storage unit 608. In addition, the program can be installed in the ROM 602 or the storage unit 608 in advance.

  The program executed by the computer may be a program that is processed in time series in the order described in this specification, or in parallel or at a necessary timing such as when a call is made. It may be a program for processing.

  The embodiments of the present technology are not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present technology.

DESCRIPTION OF SYMBOLS 1 In-vehicle system 11 Laser radar apparatus 12 Vehicle control part 13 Notification part 14 Sensor part 21 Control part 22 Measuring light light projection part 23 Light receiving part 24 Measuring part 25 Calculation part 101 Drive circuit 102 Light emitting element 202-1 thru | or 202-16 Light receiving element 253 Sampling unit 263-1 to 263-16 A / D converter 301 Detection unit 302 Command unit 311 Peak detection unit 312 Object detection unit 321 Brake control unit 322 Notification control unit 404 Display T1 to T10 Icon

Claims (5)

An object detection device for detecting an object in front of the vehicle;
An object detection system comprising: a notification unit that notifies an occupant based on a detection result by the object detection device;
If the object is not detected by said object detection device, when the vehicle is parked, the object is notified that it has not been detected, when the vehicle is traveling, the notification control for controlling anything not to notify Object detection system with a unit. 2. The control unit according to claim 1 , wherein when the object is not detected by the object detection device, the notification control unit controls to explicitly notify that the object is not detected when the vehicle is stopped. 3. Object detection system. The notification control unit, when said object is detected by the object detection device, wherein when the vehicle is parked, the object detection system according to claim 1 for controlling so as to notify the position of said detected object. The object detection system according to claim 1, wherein the notification control unit is provided in the object detection device. The object detection system according to claim 1, wherein the notification control unit is provided in the notification unit.

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