OBJECT DETECTION DEVICE AND METHOD FOR DETECTING FAILURE IN AN OBJECT DETECTION DEVICE - Patent application

Abstract

To accurately detect failures of an object detection device.SOLUTION: An object detection devices 10, 10a, 10b, or 10c for detecting an object comprises: a light receiving unit 20 that has a light receiving surface on which a plurality of light receiving elements 220 are planarly arranged that can receive incident light RL including reflected light of emitted irradiation light IL, and outputs a first light receiving signal corresponding to a light receiving state of light receiving elements in a first area U1, which is an area of use predetermined in available areas Ar1, Ar2 on the light receiving surface; an image acquisition unit 115 that acquires, using the first light receiving signal, an ambient light image Img1 indicating the light reception intensity of ambient light; and a failure detection unit 113 that detects, using the ambient light image, failures of the light receiving elements in the first area.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an object detection device. [Background technology]

[0002] Various techniques have been proposed for detecting failures in object detection devices such as imaging devices and optical distance measuring devices. For example, in Patent Document 1, a current frame image and a previous frame image taken earlier than the current frame image are used in frame images obtained by the imaging device, and brightness is compared for each pixel to detect a failure in the imaging device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2014 / 148161 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology described in Patent Document 1 requires captured images acquired in the past, which may increase the load on the object detection device or reduce responsiveness. In addition, since the presence or absence of a fault is detected for each pixel of the captured image, there is a risk that the occurrence of a fault may not be detected accurately. This problem is also true when detecting a fault in a light receiving element that receives reflected light of emitted irradiation light when the object detection device is configured with an optical distance measuring device (lidar). For this reason, a technology that can accurately detect faults in an object detection device is desired. [Means for solving the problem]

[0005] According to one embodiment of the present disclosure, an object detection device (10, 10a, 10b, 10c) for detecting an object is provided. The object detection device has a light receiving surface on which a plurality of light receiving elements (220) capable of receiving incident light (RL) including reflected light of emitted irradiation light (IL) are arranged in a planar manner, and a light receiving unit (20) that outputs a first light receiving signal corresponding to a light receiving state of the light receiving elements in the first region and a third light receiving signal corresponding to a light receiving state of the light receiving elements in the third region, the first light receiving signal being a first region (U1) and the third region being a third region different from or partially overlapping the first region, the third light receiving signal being a second region (U2) and the third region being a second region (U3) and the third region being a second region (U4) and the third region being a second region (U5) and the third region being a second region (U6). No. A first ambient light image (Img1) showing the received light intensity of the ambient light is obtained using the and using the third light receiving signal, obtain a second light receiving signal indicating a received light intensity of the ambient light. an image acquisition unit (115) that acquires a third ambient light image (Img3); and a fault detection unit (113) that detects a fault in the light receiving element in the first region by using the first ambient light image and the third ambient light image, , the luminance value is equal to or less than a first predetermined value or equal to or more than a second predetermined value different from the first predetermined value. and a failure detection unit that detects a failure of the light receiving element in the first region when a position of a pixel group has moved in the third ambient light image.

[0006] According to this type of object detection device, an ambient light image is acquired using a first light receiving signal corresponding to the light receiving state of the light receiving elements in a first region on a light receiving surface on which multiple light receiving elements are arranged in a planar shape, and the acquired ambient light image is used to detect failures in the light receiving elements in the first region, thereby reducing the load on the object detection device and accurately detecting failures in the light receiving elements.

[0007] The present disclosure may be realized in various forms, for example, in the form of a fault detection device for an object detection device, a fault detection method for an object detection device, a computer program for realizing these devices and methods, a storage medium storing such a computer program, etc. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is an explanatory diagram showing a schematic configuration of an object detection device. [Diagram 2]FIG. 2 is an explanatory diagram illustrating a schematic configuration of a light receiving element array. [Diagram 3] FIG. 13 is an explanatory diagram showing an example of a usage area. [Figure 4] FIG. 2 is a block diagram showing a functional configuration of a control device. [Diagram 5] FIG. 4 is a top view of a first moving mechanism and a second moving mechanism. [Figure 6] FIG. 4 is a side view of a first moving mechanism and a second moving mechanism. [Figure 7] 7 is a cross-sectional view showing a cross section taken along line 7-7 in FIG. 5. [Figure 8] 8 is a cross-sectional view showing a cross section taken along line 8-8 in FIG. 6. [Figure 9] 13 is a flowchart showing a processing procedure of a failure detection process. [Figure 10] 5A to 5C are explanatory diagrams showing examples of ambient light images acquired in each operation mode. [Figure 11] FIG. 11 is a top view of a first moving mechanism and a second moving mechanism in the second embodiment. [Figure 12] FIG. 11 is a side view of a first moving mechanism and a second moving mechanism in the second embodiment. [Figure 13] 13 is a cross-sectional view showing a cross section taken along line 13-13 in FIG. 11. [Figure 14] 14 is a cross-sectional view showing a cross section taken along line 14-14 in FIG. 12. [Figure 15] 10 is an explanatory diagram illustrating a schematic view of a state in which a second movable part moves. FIG. [Figure 16] 10 is an explanatory diagram illustrating a schematic view of a state in which a second movable part moves. FIG. [Figure 17] 10A and 10B are explanatory diagrams illustrating a state in which a lock pin moves. [Figure 18] FIG. 13 is a top view of a first moving mechanism and a second moving mechanism in the third embodiment. [Figure 19] FIG. 13 is a side view of a first moving mechanism and a second moving mechanism in the third embodiment. [Figure 20] 19 is a cross-sectional view showing a cross section taken along line 20-20 in FIG. 18. [Figure 21]21 is a cross-sectional view showing a cross section taken along line 21-21 in FIG. 19. [Figure 22] 10 is an explanatory diagram illustrating a schematic view of a state in which a second movable part moves. FIG. [Diagram 23] FIG. 13 is a top view of a first moving mechanism and a second moving mechanism in the fourth embodiment. [Figure 24] FIG. 13 is a side view of a first moving mechanism and a second moving mechanism in the fourth embodiment. [Diagram 25] 25 is a cross-sectional view showing a cross section taken along line 25-25 in FIG. 23. [Figure 26] 26 is a cross-sectional view showing a cross section taken along line 26-26 in FIG. 24. [Figure 27] 10 is an explanatory diagram illustrating a schematic view of a state in which a second movable part moves. FIG. [Figure 28] FIG. 13 is an explanatory diagram showing the concept of fault detection according to the fifth embodiment. [Figure 29] 13 is a flowchart showing a processing procedure of a failure detection process according to the fifth embodiment. [Diagram 30] FIG. 23 is an explanatory diagram showing a change in the use area according to the sixth embodiment. [Diagram 31] FIG. 23 is an explanatory diagram showing a change in the use area according to the seventh embodiment. [Diagram 32] FIG. 23 is an explanatory diagram showing a change in the use area according to the eighth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A. First embodiment: A1. Equipment configuration: As shown in FIG. 1, an object detection device 10 according to an embodiment of the present disclosure includes a distance measuring device 200 and a control device 100. The object detection device 10 is mounted on a vehicle, for example, and detects objects present around the vehicle by acquiring information about the surroundings of the vehicle, for example, distances between targets around the vehicle. FIG. 1 shows three mutually orthogonal axes, namely, an X-axis, a Y-axis, and a Z-axis. The X-axis is parallel to the horizontal direction HD, and the Z-axis is parallel to the vertical direction VD. The X-axis, the Y-axis, and the Z-axis shown in other drawings all correspond to the X-axis, the Y-axis, and the Z-axis shown in FIG. 1. When specifying a direction, a positive direction is indicated by "+" and a negative direction is indicated by "-", and positive and negative signs are used in combination to indicate the direction. The X-direction corresponds to a subordinate concept of the first direction in the present disclosure, and the Z-direction corresponds to a subordinate concept of the second direction in the present disclosure. Moreover, the +X direction corresponds to a subordinate concept on one side of the first direction, and the +Z direction corresponds to a subordinate concept on one side of the second direction.

[0010] The distance measuring device 200 is a LiDAR (Light Detection And Ranging). The distance measuring device 200 detects the distance and shape of a target relative to the vehicle by emitting irradiation light IL and receiving the reflected light reflected by the target. In addition to the reflected light from the target, the distance measuring device 200 receives light other than the reflected light, such as sunlight, street light, headlight light of other vehicles, and environmental light (hereinafter also referred to as "background light") such as light reflected by the target. The distance measuring device 200 specifies the light that is obtained by removing the background light from the received light as the reflected light from the target, and calculates the time from when the irradiation light IL is emitted to when the reflected light is received, that is, the time of flight TOF of light, as the distance to the target.

[0011] The distance measuring device 200 includes a light receiving unit 20, a light emitting unit 30, a scanning mirror 42, an electric motor 40, and a rotation angle sensor 41. For example, when scanning in the horizontal direction HD, the distance measuring device 200 has a predetermined scanning angle range SR in the horizontal direction HD, and the light emitting unit 30 emits the irradiation light IL and the light receiving unit 20 receives the incident light RL in units of unit scanning angles SC obtained by dividing the scanning angle range SR into a plurality of angles, thereby acquiring detection points throughout the entire scanning angle range SR and realizing distance measurement. The unit scanning angle SC defines the resolution of the distance measuring device 200 or the resolution of the distance measurement result obtained by the distance measuring device 200, and the smaller the unit scanning angle SC becomes, i.e., the more the number of detection points becomes, the higher the resolution and resolution in the horizontal direction HD become. The acquisition of detection points in the distance measuring device 200, i.e., the light emission and light reception process, is performed when scanning the scanning angle range SR in one direction or when scanning the scanning angle range SR back and forth in both directions. The scanning direction may be the vertical direction VD. In this case, the X direction is parallel to the vertical direction VD, and the Z direction is parallel to the horizontal direction HD.

[0012] The light receiving unit 20 includes a light receiving element array 22, a light receiving control unit 21, and a light receiving lens 23 (not shown in FIG. 1), and performs light receiving processing to output a light receiving signal corresponding to the light receiving state of the incident light including the reflected light of the irradiation light IL emitted from the light emitting unit 30, for example, the amount of received light and the intensity of received light.

[0013] As shown in FIG. 2, the light receiving element array 22 is an optical sensor that has a light receiving surface on which a plurality of light receiving elements 220 are arranged vertically and horizontally, i.e., two-dimensionally, and can receive incident light. For example, each light receiving element is constituted by a SPAD (Single Photon Avalanche Diode) or other photodiode. In this embodiment, a plurality of use areas are set in advance in the light receiving element array 22. The use area is exclusively selected according to the operation mode of the distance measuring device 200, and light receiving processing is performed using the light receiving elements 220 in the selected use area. The operation modes include a "normal mode" in which the distance measuring device 200 operates normally, a "failure detection mode" in which a failure of the light receiving element 220 is detected in the normal mode, and a "failure countermeasure mode" in which, when a failure of the light receiving element 220 is detected in the failure detection mode, normal operation is performed using the light receiving element 220 in which no failure is detected.

[0014] As shown in Fig. 2, the light receiving element array 22 is divided into a first usable area Ar1 and a second usable area Ar2. For example, the first usable area Ar1 is an area used in the normal mode and the fault detection mode. The second usable area Ar2 is an area used in the fault countermeasure mode. In other words, the first usable area Ar1 is an area used for light receiving processing in normal times, and the second usable area Ar2 can be said to be a preliminary area used for light receiving processing when a fault occurs in the first usable area Ar1.

[0015] As shown by hatching in the upper part of Fig. 3, in the normal mode, a first region U1 in the first usable region Ar1 is used. The first region U1 is composed of a plurality of light receiving elements 220 in a predetermined range in the first usable region Ar1. The light receiving unit 20 outputs a light receiving signal (hereinafter referred to as a "first light receiving signal") according to the light receiving state of the light receiving elements 220 in the first region U1.

[0016] As shown by hatching in the lower left of FIG. 3, a third region U3 is used in the failure detection mode. The third region U3 is a region obtained by translating the first region U1 in the +Z direction, and may partially overlap with the first region, or may not overlap with the first region. The third region U3 may also be a region obtained by translating the first region U1 in the -Z direction. The light receiving unit 20 outputs a light receiving signal (hereinafter referred to as a "third light receiving signal") according to the light receiving state of the light receiving element 220 in the third region U3.

[0017] As shown by hatching in the lower right of Fig. 3, the second region U2 is used in the failure countermeasure mode. The second region U2 is a region obtained by translating the first region U1 in the +X direction. The light receiving unit 20 outputs a light receiving signal (hereinafter referred to as a "second light receiving signal") according to the light receiving state of the light receiving element 220 in the second region U2.

[0018] The distance measuring device 200 includes a mechanism for changing the areas U1, U2, and U3, and the mechanism is controlled in response to switching of the operation mode, thereby realizing light receiving processing using the areas U1, U2, and U3 according to each operation mode. The mechanism for changing the areas U1, U2, and U3 will be described later.

[0019] The light receiving control unit 21 performs a light receiving process to output an incident light intensity signal corresponding to the amount or intensity of incident light incident on the light receiving element 220 in the areas U1, U2, and U3, based on a unit scan angle SC at which light is emitted by the light emitting unit 30.

[0020] The light emitting unit 30 includes a light emission control unit 31, a light emitting element 32, and a collimator lens, and irradiates the irradiation light IL once or discretely multiple times per unit scan angle SC. The light emitting element 32 is, for example, one or more infrared laser diodes, and emits infrared laser light as the irradiation light IL. The light emitting unit 30 may include a single light emitting element 32 in the vertical direction VD, or may include multiple light emitting elements 32. The light emission control unit 31 drives the light emitting element 32 by a drive signal of a pulse drive waveform in response to a light emission control signal input from the control device 100 for each unit scan angle SC, which instructs the light emitting element 32 to emit light, to execute emission of infrared laser light. The infrared laser light irradiated from the light emitting unit 30 is reflected by the scanning mirror 42 and is emitted toward the outside of the distance measuring device 200, i.e., toward a range in which detection of an object is desired.

[0021] The electric motor 40 is provided with a motor driver (not shown). The electric motor 40 is provided with a rotation angle sensor 41 for detecting the rotation angle of the electric motor 40. The electric motor driver receives a rotation angle signal from the rotation angle sensor 41, receives a rotation angle instruction signal output by the control device 100, and changes the voltage applied to the electric motor 40 to control the rotation angle of the electric motor 40. The electric motor 40 is, for example, an ultrasonic motor, a brushless motor, or a brush motor, and is provided with a well-known mechanism for reciprocating within the scanning angle range SR. A scanning mirror 42 is attached to the tip of the output shaft of the electric motor 40.

[0022] The scanning mirror 42 is a reflector, i.e., a mirror, that scans the illumination light IL emitted from the light-emitting unit 30 in the horizontal direction HD, and is driven reciprocally by the electric motor 40 to scan the scanning angle range SR in the horizontal direction HD. The scanning mirror 42 scans the detection light and receives the reflected light in a scanning angle range of, for example, 120 degrees or 180 degrees. When the scanning mirror 42 is provided with a single light-emitting element or when the detection light cannot be emitted over the entire area of ​​the vertical direction VD, the scanning mirror 42 may scan in the vertical direction VD in addition to the horizontal direction HD, that is, change the scanning position in the vertical direction VD. To achieve scanning in the horizontal direction HD and the vertical direction VD, the scanning mirror 42 may be a multifaceted mirror, for example, a polygon mirror, or may be a single-faceted mirror provided with a mechanism for swinging in the vertical direction VD, or may be another single-faceted mirror that swings in the vertical direction VD. Scanning mirror 42 may be rotationally driven by motor 40 to perform rotational scanning. In this case, light emission and reception processes by light-emitting unit 30 and light-receiving unit 20 may be performed in accordance with scan angle range SR.

[0023] The illumination light IL emitted from the light-emitting unit 30 is reflected by the scanning mirror 42 and scanned over a scanning angle range SR in the horizontal direction HD in units of unit scanning angles SC. The illumination light IL is reflected by the target and reflected light is reflected by the scanning mirror 42 to the light-receiving unit 20 at each unit scanning angle SC and is incident on the light-receiving unit 20. The unit scanning angle SC at which the light-receiving process is performed is sequentially incremented, and as a result, scanning for the light-receiving process over a desired scanning angle range SR is possible. If the detection light cannot be irradiated over the entire vertical direction VD, the irradiation position in the vertical direction VD is changed during each scan in the horizontal direction HD, and multiple scans in the horizontal direction HD are performed. The light-emitting unit 30 and the light-receiving unit 20 may be rotated by the electric motor 40 together with the scanning mirror 42, or may be separate from the scanning mirror 42 and not rotated by the electric motor 40. Furthermore, instead of having a scanning mirror 42, a configuration may be provided in which a plurality of light-emitting elements 32 and a light-receiving element array 22 are arranged in an array, laser light is sequentially directly emitted to the outside world, and the reflected light is directly received.

[0024] As shown in FIG. 4, the control device 100 includes a CPU 110, a memory 103, and an input / output interface 101. The CPU 110, the memory 103, and the input / output interface 101 are connected to each other via a bus 105 so as to be able to communicate in both directions. The memory 103 includes a ROM, a RAM, and an EEPROM. The light emission control unit 31, the light reception control unit 21, the electric motor 40, and the rotation angle sensor 41 are connected to the input / output interface 101 via control signal lines. A light emission control signal is transmitted to the light emission control unit 31, and a light reception control signal is transmitted to the light reception control unit 21, instructing a light reception process for acquiring ambient light or a light reception process for detecting an object corresponding to the transmission of the light emission control signal, and a light reception signal is received from the light reception control unit 21. A rotation angle instruction signal is transmitted to the electric motor 40, and a rotation angle signal is received from the rotation angle sensor 41.

[0025] The CPU 110 loads and executes the programs stored in the memory 103 to function as a control unit 111 , a fault detection unit 113 , an image acquisition unit 115 , and an object detection unit 117 .

[0026] The control unit 111 controls the operation of the entire object detection device 10. The failure detection unit 113 detects a failure of the light receiving element 220 in the first usable area Ar1, more specifically, the light receiving element 220 in the first area U1. The image acquisition unit 115 acquires an ambient light image indicating the received light intensity of the ambient light. The object detection unit 117 detects objects around the vehicle using the light receiving signal output by the light receiving unit 20.

[0027] The mechanism for changing the regions U1, U2, and U3 will be described with reference to Figures 5, 6, 7, and 8. The distance measuring device 200 further includes a first moving mechanism 50 and a second moving mechanism 70. The first moving mechanism 50 is a mechanism for moving the light receiving element array 22 in a horizontal direction HD, for example, in the +X direction, and is used in this embodiment to move the use region from the first region U1 to the second region U2 in the failure countermeasure mode. The second moving mechanism 70 is a mechanism for moving the light receiving element array 22 in a vertical direction VD, for example, in the +Z direction, and is used in this embodiment to move the use region from the first region U1 to the third region U3 in the failure detection mode.

[0028] 5 and 6, the first moving mechanism 50 and the second moving mechanism 70 are arranged in the order of the light-receiving lens 23, the light-receiving element array 22, the second moving mechanism 70, and the first moving mechanism 50 from the -Y direction side, and are fixed to a base member 91. The light-receiving element array 22 is attached to the surface of the second moving mechanism 70 on the -Y direction side.

[0029] As shown in FIGS. 5, 6, 7, and 8, the first moving mechanism 50 includes a pair of first movable parts 51a and 51b, a motor 53, a guide 55, a screw mechanism 60, and an elastic member 57. The first movable parts 51a and 51b are members for moving the light receiving element array 22 in parallel in the X direction relative to the light receiving lens 23. The -Y direction surface of the first movable part 51b is fixed to the +Y direction surface of the second moving mechanism 70. The first movable part 51b moves in the X direction as the screw mechanism 60 is driven. As the first movable part 51b moves in the X direction, the second moving mechanism 70 and the light receiving element array 22 move in the X direction in conjunction with the first movable part 51b.

[0030] Motor 53 is attached to the surface of first movable part 51a on the +X direction side, and rotates screw mechanism 60 in response to a control signal from control unit 111. Guide 55 guides movement of first movable part 51b in the X direction while maintaining the parallel state of light receiving element array 22 and light receiving lens 23 in the X direction. As shown in Fig. 6, guide 55 has a trapezoidal shape with the base on the -Y direction side, and therefore can suppress wobbling of light receiving element array 22 and light receiving lens 23.

[0031] The screw mechanism 60 includes a male screw 61 and a female screw 62. In the normal mode, the male screw 61 and the female screw 62 are engaged with each other. In the failure countermeasure mode, when the motor 53 rotates the male screw 61, the engaged state between the male screw 61 and the female screw 62 is relaxed, and the first movable part 51b moves in the X direction. At this time, the male screw 61 is rotated until the movement amount of the first movable part 51b reaches a predetermined movement amount. The predetermined movement amount is, for example, several millimeters.

[0032] The elastic member 57 covers the outer circumferential surface of the end portion on the -X direction side of the male screw 61. The elastic member 57 deforms (expands and contracts) in the X direction according to the driving state of the screw mechanism 60. The elastic member 57 is, for example, a compression coil spring, silicone rubber, or the like.

[0033] The second moving mechanism 70 has a similar configuration to the first moving mechanism 50. Specifically, as shown in Fig. 5 to Fig. 8, the second moving mechanism 70 includes a pair of second movable parts 71a and 71b, a motor 73, a guide 75, a screw mechanism 80, and an elastic member 77.

[0034] The second movable parts 71a and 71b are members for moving the light receiving element array 22 in parallel in the Z direction relative to the light receiving lens 23. The second movable part 71b moves in the Z direction as the screw mechanism 80 is driven. As the second movable part 71b moves in the Z direction, the light receiving element array 22 moves in the Z direction in conjunction with the second movable part 71b.

[0035] Motor 73 is attached to the surface of second movable part 71a on the +X direction side, and rotates screw mechanism 80 in response to a control signal from control unit 111. Guide 75 guides movement of second movable part 71b in the Z direction while maintaining the parallel state of light receiving element array 22 and light receiving lens 23 in the Z direction. Like guide 55 of first movement mechanism 50, guide 75 has a trapezoidal shape with the base on the -Y direction side. Therefore, rattling of light receiving element array 22 and light receiving lens 23 can be suppressed.

[0036] The screw mechanism 80 includes a male screw 81 and a female screw 82. In the normal mode, the male screw 81 and the female screw 82 are engaged with each other. In the failure countermeasure mode, when the motor 73 rotates the male screw 81, the engaged state between the male screw 81 and the female screw 82 is relaxed, and the second movable part 71b moves in the Z direction. At this time, the male screw 81 is rotated until the movement amount of the second movable part 71b reaches a predetermined movement amount. The predetermined movement amount is, for example, several tens of micrometers.

[0037] The elastic member 77 covers the outer circumferential surface of the end portion on the -Z direction side of the male screw 61. The elastic member 77 deforms (expands and contracts) in the Z direction according to the driving state of the screw mechanism 80. The elastic member 77 is, for example, a compression coil spring, silicone rubber, or the like.

[0038] A2.Fault detection process: 9 is repeatedly executed at a predetermined time interval during the object detection process executed by the object detection unit 117. In step S10, the image acquisition unit 115 acquires an ambient light image. Specifically, the image acquisition unit 115 acquires the ambient light image using a first light reception signal output by a light reception process using the light receiving elements 220 in the first region U1.

[0039] In step S15, the fault detection unit 113 determines whether or not a black line is detected in the ambient light image. Specifically, the fault detection unit 113 determines whether or not a black line BL, i.e., a dark line, appears along the X direction in the image data of the ambient light image Img1 in normal mode, as shown on the left side of FIG. 10. More specifically, the fault detection unit 113 determines whether or not a group of pixels having a luminance value of 0 (zero) is arranged along the X direction in the image data of the ambient light image Img1, that is, whether or not a pixel row having a luminance value of 0 that forms one line in the scanning direction exists. Note that the luminance value is not limited to zero, and a value equal to or less than a luminance value that is a reference value for low luminance may be used.

[0040] If it is determined that a black line is detected in the ambient light image (step S15: YES), the failure detection unit 113 determines that the light receiving element 220 in the first region U1 may be malfunctioning, and in step S20 causes the control unit 111 to transition to a failure detection mode. Specifically, in step S21, the control unit 111 controls the second moving mechanism 70 to change the usage region from the first region U1 to the third region U3. The control unit 111 drives the motor 73 to rotate the screw mechanism 80, thereby moving the second movable part 71b in the +Z direction or the -Z direction.

[0041] In step S25, the image acquisition unit 115 acquires an ambient light image. Specifically, the image acquisition unit 115 acquires the ambient light image using a third light reception signal output by a light reception process using the light receiving elements 220 in the third region U3.

[0042] In step S30, the fault detection unit 113 determines whether the position of the black line detected in the above-mentioned step S15 has moved. Specifically, the fault detection unit 113 determines whether the BL position of the black line has moved in the +Z direction or the -Z direction in association with changing the used region from the first region U1 to the third region U3 in the image data of the ambient light image Img2 in the fault detection mode shown in the center of Fig. 10. That is, the fault detection unit 113 determines whether the group of pixels having a luminance value of 0 (zero), detected in the above-mentioned step S15, in the image data of the ambient light image Img2, has moved to a pixel position in the +Z direction or a pixel position in the -Z direction with respect to the pixel position in the image data of the ambient light image Img1.

[0043] When it is determined that the position of the black line has moved (step S30: YES), the failure detection unit 113 determines that the light receiving element 220 in the first region U1 has failed, and in step S35, causes the control unit 111 to transition to a failure countermeasure mode. Specifically, in step S36, the control unit 111 controls the first moving mechanism 50 and the second moving mechanism 70 to change the use region from the third region U3 to the second region U2. More specifically, the control unit 111 drives the motor 73 of the second moving mechanism 70 to rotate the screw mechanism 80, thereby moving the second movable part 71b in the -Z direction, and returning the use region from the third region U3 to the first region U1. Next, the control unit 111 drives the motor 53 of the first moving mechanism 50 to rotate the screw mechanism 60, thereby moving the first movable part 51b in the +X direction, and moving the use region from the first region U1 to the second region U2. As a result, the black line BL is no longer detected in the image data of the ambient light image Img3 in the failure countermeasure mode shown on the right side of Fig. 10. After that, in the object detection process executed by the object detection unit 117, the light receiving elements 220 in the second region U2 are used.

[0044] If it is determined in step S30 that the position of the black line has not moved (step S30: NO), the failure detection unit 113 determines that the light receiving element 220 in the first region U1 is not faulty, and in step S40, causes the control unit 111 to transition to normal mode. Specifically, in step S41, the control unit 111 controls the second moving mechanism 70 to move the second movable part 71b in the -Z direction, thereby returning the usage region from the third region U3 to the first region U1. Thereafter, in the object detection process executed by the object detection unit 117, the light receiving element 220 in the first region U1 is used.

[0045] If it is determined in the above-mentioned step S15 that a black line has not been detected (step S15: NO), or after the above-mentioned step S36 is executed, or after the above-mentioned step S41 is executed, the failure detection process ends.

[0046] According to the object detection device 10 of the first embodiment having the above configuration, an ambient light image Img1 is acquired using a first light receiving signal corresponding to the light receiving state of the light receiving elements in a first region U1 in the light receiving element array 22 in which a plurality of light receiving elements 220 are arranged in a planar shape, and a failure of the light receiving elements 220 in the first region U1 is detected using the acquired ambient light image Img1, so that the load on the object detection device 10 can be reduced while accurately detecting a failure of the light receiving elements 220. Specifically, according to the object detection device 10, it is not necessary to store ambient light images acquired in the past in the memory 103 in detecting a failure of the light receiving elements 220, so that the storage capacity used by the memory 103 can be reduced. In addition, since image data of the ambient light image is not compared with image data of ambient light images acquired in the past for each pixel, the load on the CPU 110 can be reduced and the presence or absence of an occurrence of a failure can be accurately detected.

[0047] When a failure is detected in the light receiving element 220 in the first region U1, an object is detected using the second light receiving signal corresponding to the light receiving state of the light receiving element 220 in the second region U2, so that the object can be detected using the light receiving element 220 in which no failure is detected. Therefore, the object can be detected with high accuracy.

[0048] When a group of pixels whose luminance values ​​are equal to or less than a predetermined value are arranged along the X direction in the image data of the ambient light image Img1, it is detected that the light receiving element 220 in the first region U1 may be malfunctioning, so that it is easy to detect the possibility that the light receiving element 220 in the first region U1 may be malfunctioning.

[0049] When it is detected that the light receiving element 220 in the first region U1 may be faulty, the ambient light image Img2 is acquired again using a third light receiving signal corresponding to the light receiving state of the light receiving element 220 in the third region U3, and when a group of pixels whose luminance values ​​are equal to or less than a predetermined value in the image data of the reacquired ambient light image Img2 moves in the +Z direction relative to the original pixel position as it moves from the first region U1 to the third region U3 of the usage region, it is detected that the light receiving element 220 in the first region U1 is faulty, so that a fault in the light receiving element 220 in the first region U1 can be easily detected.

[0050] The first moving mechanism 50 has the first movable parts 51a and 51b that move the light receiving element array 22 along the X direction by driving the screw mechanism 60 by the motor 53, so that the light receiving element array 22 can be moved along the X direction with a simple configuration. The second moving mechanism 70 has the second movable parts 71a and 71b that move the light receiving element array 22 along the Z direction by driving the screw mechanism 80 by the motor 73, so that the light receiving element array 22 can be moved along the Z direction with a simple configuration. Note that instead of or in addition to the configuration in which the light receiving element array 22 is mechanically moved to move the first region U1, a configuration in which the optical system including the light receiving lens 23 is mechanically driven to change the first region U1 on the light receiving element array 22, that is, the focal region, may be provided. This is because the focal region and the focal position on the light receiving element array 22 are determined by the relative positional relationship between the light receiving lens 23 and the light receiving element array 22.

[0051] B. Second embodiment: In the following, the same reference numerals are used for the same configurations as those in the above-mentioned embodiment, and the description will be omitted. As shown in Figures 11, 12, 13, and 14, the object detection device 10a of the second embodiment differs from the object detection device 10 of the first embodiment in that the first movement mechanism 50 is replaced with a first movement mechanism 50a, and the second movement mechanism 70 is replaced with a second movement mechanism 70a.

[0052] The first moving mechanism 50a differs from the first moving mechanism 50 of the first embodiment in that the motor 53 and the screw mechanism 60 are omitted, and that a lock mechanism 64 and an electromagnet 63 are provided.

[0053] The lock mechanism 64 restricts the movement of the first movable parts 51a and 51b in the X direction. The lock mechanism 64 switches between a "locked state" in which the first movable parts 51a and 51b cannot move in the X direction and a "released state" in which the first movable parts 51a and 51b can move in the X direction, depending on whether or not current is applied to the electromagnet 63. The lock mechanism 64 includes a lock pin 65 and a spring member 66. The lock pin 65 is located on the -Z direction side of the spring member 66 in the first movable part 51b and abuts against the spring member 66. In the locked state, the lock pin 65 is biased in the -Z direction by the spring member 66, and the tip of the lock pin 65 is fixed at a predetermined position in the through hole h1 in the first movable part 51b. The spring member 66 is located on the -Z direction side of the electromagnet 63 in the first movable part 51b. The spring member 66 controls the movement of the lock pin 65 in the Z direction by a magnetic force generated when the electromagnet 63 is energized.

[0054] The electromagnet 63 is disposed on the surface of the first movable part 51b in the +Z direction. The electromagnet 63 generates a magnetic force when current is applied, and the magnetic force disappears when current is stopped. That is, by controlling current application to the electromagnet 63, the change in polarity of the electromagnet 63 and the disappearance of the magnetic field are adjusted. The excited electromagnet 63 exerts its magnetic force on the spring member 66 to control the insertion and removal operation of the lock pin 65 from the through hole h1. That is, the electromagnet 63 functions as a drive part of the lock mechanism 64. The start and stop of current application to the electromagnet 63 are controlled by the control part 111.

[0055] The second moving mechanism 70a differs from the second moving mechanism 70 of the first embodiment in that the motor 73 and the screw mechanism 80 are omitted, and that a lock mechanism 84 and an electromagnet 83 are provided.

[0056] The lock mechanism 84 restricts the movement of the second movable parts 71a and 71b in the Z direction. The lock mechanism 84 switches between a "locked state" in which the second movable parts 71a and 71b cannot move in the Z direction and a "released state" in which the second movable parts 71a and 71b can move in the Z direction, depending on whether or not current is applied to the electromagnet 83. The lock mechanism 84 includes a lock pin 85 and a spring member 86, similar to the lock mechanism 64 of the first moving mechanism 50a. The lock pin 85 is located on the -X direction side of the spring member 86 in the second movable part 71b and abuts against the spring member 86. In the locked state, the lock pin 85 is biased in the -X direction by the spring member 86, and the tip of the lock pin 85 is fixed at a predetermined position in the through hole h2 in the second movable part 71b. The spring member 86 is disposed in the second movable portion 71b on the -X direction side of the electromagnet 83. The spring member 86 controls the movement of the lock pin 85 in the X direction by a magnetic force generated when the electromagnet 83 is energized.

[0057] The electromagnet 83 is disposed on the surface of the second movable part 71b in the +X direction. Similar to the electromagnet 63 of the first movement mechanism 50a, the electromagnet 83 generates a magnetic force when current is applied and loses the magnetic force when current is stopped. The excited electromagnet 83 exerts its magnetic force on the spring member 86 to control the insertion and removal operation of the lock pin 85 from the through hole h2.

[0058] 15 and 16, a procedure for moving the light receiving element array 22 in the +Z direction in the second moving mechanism 70a will be described. FIG. 15 corresponds to FIG. 14, and FIG. 16 corresponds to FIG. 13. In the locked state shown on the left side of FIG. 15, the electromagnet 83 is de-energized, and the tip (the end in the -Z direction) of the lock pin 85 is fixed in the through hole h2 by the biasing force of the spring member 86 in the -Z direction. Therefore, the movement of the second movable part 71b in the Z direction is restricted, and the light receiving element array 22 is fixed at a predetermined position in the normal mode. When the electromagnet 83 is energized, the electromagnet 83 is excited, and the lock pin 85 is attracted to the electromagnet 83 side (in the +Z direction) by the magnetic force of the electromagnet 83. As a result, as shown on the right side of FIG. 15, the tip of the lock pin 85 is pulled out of the through hole h2, and the locked state is released to the released state.

[0059] As shown in the left side of Fig. 16, when the locked state is released, the biasing force of the elastic member 77 in the -Z direction weakens, and the elastic member 77 stretches in the +Z direction. As a result, as shown in the right side of Fig. 16, the second movable part 71b moves in the +Z direction, and the center position in the Z direction of the light receiving element array 22 moves in the +Z direction, as shown by the dashed line.

[0060] The operation of the lock pin 85 when transitioning from the locked state to the released state and the operation of the lock pin 85 when transitioning from the released state to the locked state again will be described with reference to Fig. 17. Fig. 17 corresponds to Fig. 15 and shows an enlarged view of the vicinity of the through hole h2. In Fig. 17, the axis CX shown by the dashed line is the central axis of the through hole h2 in the Y direction, and the axis AX shown by the dashed line is the central axis of the lock pin 85 in the Y direction. In the locked state shown in the leftmost drawing of Fig. 17, the lock pin 85 is fixed at a predetermined position in the through hole h2 with its own axis CX coinciding with the axis AX of the through hole h2.

[0061] As shown in the leftmost and second leftmost diagrams in FIG. 17, when the state transitions from the locked state to the unlocked state, the lock pin 85 rises to the side where the electromagnet 83 is arranged (+X direction). As a result, the second movable part 71b becomes movable in the +Z direction, and the position of the through hole h2 also moves with the movement of the second movable part 71b. Therefore, the position of the axis AX of the lock pin 85 is disposed at a position shifted by the movement amount of the second movable part 71b with respect to the axis CX of the through hole h2. Thereafter, as shown in the third and rightmost diagrams from the left in FIG. 17, when the state transitions from the unlocked state to the locked state, the lock pin 85 descends to the through hole h2 side, and the tip of the lock pin 85 is inserted into the through hole h2. At this time, the second movable part 71b is returned to its original position, so that the position of the axis CX of the lock pin 85 is returned to its original position and coincides with the axis AX of the through hole h2.

[0062] As shown in Fig. 17, the tip of the lock pin 85 has a tapered shape. This allows the lock pin 85 to be easily inserted into the through hole h2 and allows the lock pin 85 to be more firmly fixed in the through hole h2. In the example shown in Fig. 17, the lock pin 85 is inserted into the through hole h2 along the axis AX of the through hole h2, but it may be inserted in a direction intersecting the axis AX. This prevents the lock pin 85 from coming out of the through hole h2 due to vibration of the vehicle or the like.

[0063] According to the object detection device 10a of the second embodiment having the above configuration, the first moving mechanism 50a includes the locking mechanism 64 that restricts the movement of the light receiving element array 22 in the X direction, the electromagnet 63 that controls the switching between the locked state and the unlocked state of the locking mechanism 64, and the first movable parts 51a and 51b that move the light receiving element array 22 along the X direction when the locking mechanism 64 is in the unlocked state, so that the first moving mechanism can be made to have a simpler structure. The second moving mechanism 70a includes the locking mechanism 84 that restricts the movement of the light receiving element array 22 in the Z direction, the electromagnet 83 that controls the switching between the locked state and the unlocked state of the locking mechanism 84, and the second movable parts 71a and 71b that move the light receiving element array 22 along the Z direction when the locking mechanism 84 is in the unlocked state, so that the second moving mechanism 70a can be made to have a simpler structure.

[0064] C. Third embodiment: As shown in FIGS. 18, 19, 20 and 21, an object detection device 10b of the third embodiment differs from the object detection device 10 of the first embodiment in that the second movement mechanism 70 is replaced with a second movement mechanism 70b.

[0065] The second moving mechanism 70b differs from the second moving mechanism 70 of the first embodiment in that the motor 73 and the screw mechanism 80 are omitted, a piezoelectric body 87 is provided, and an elastic member 77a is provided instead of the elastic member 77.

[0066] The piezoelectric body 87 is a member formed of a material having a piezoelectric effect, such as a piezo element, and is deformed according to a voltage applied to an electrode (not shown). The application of a voltage to the piezoelectric body 87 is controlled by the control unit 111, and a voltage is applied when switching the above-mentioned operation mode. The elastic member 77a is disposed between the surface of the second movable part 71a in the -Z direction and the surface of the second movable part 71b in the +Z direction.

[0067] A procedure for moving the light receiving element array 22 in the +Z direction by the second moving mechanism 70b will be described with reference to FIG. 22. FIG. 22 corresponds to FIG. 20. The left side of FIG. 22 shows the second moving mechanism 70b in the normal mode, and the right side of FIG. 22 shows the second moving mechanism 70b in the failure detection mode. In the normal mode, no voltage is applied to the piezoelectric body 87. Therefore, as shown on the left side of FIG. 22, the elastic member 77a presses the piezoelectric body 87 against the surface of the second movable part 71a in the +Z direction by the biasing force. This restricts the movement of the light receiving element array 22 in the Z direction.

[0068] When a voltage is applied to the piezoelectric body 87 during transition from the normal mode to the fault detection mode, the piezoelectric body 87 undergoes elastic deformation, as shown on the right side of Fig. 22. With this deformation, the elastic member 77a is compressed in the +Z direction. As a result, the second movable part 71b is pushed up in the +Z direction, and the center position of the light receiving element array 22 in the Z direction moves in the +Z direction, as shown by the dashed line. Note that, to return the light receiving element array 22 to its original position, application of voltage to the piezoelectric body 87 can be stopped.

[0069] According to the object detection device 10b of the third embodiment having the above configuration, the second moving mechanism 70b has the piezoelectric body 87 and the second movable parts 71a and 71b that move the light receiving element array 22 along the Z direction by applying the piezoelectric body 87, so that the second moving mechanism 70b can have a simpler structure. The first moving mechanism 50 may also be provided with a piezoelectric body as an actuator, similar to the second moving mechanism 70b. In this case, the motor 53 and the screw mechanism 60 are omitted, and an elastic member 77a is provided instead of the elastic member 77.

[0070] D. Fourth embodiment: As shown in FIGS. 23, 24, 25 and 26, object detection device 10c of the fourth embodiment differs from object detection device 10b of the third embodiment in that object detection device 10c includes a second moving mechanism 70c instead of second moving mechanism 70b.

[0071] The second moving mechanism 70c differs from the second moving mechanism 70b of the third embodiment in that it omits the piezoelectric body 87, is provided with an electromagnet 83 and an iron core 88, and is provided with an elastic member 77b instead of the elastic member 77a.

[0072] The electromagnet 83 is disposed on the surface of the second movable part 71b in the +Z direction. The electromagnet 83 has a configuration similar to that of the electromagnet of the second embodiment, is excited by energization, and exerts its magnetic force on the iron core 88 to control the movement of the second movable part 71b in the Z direction. The iron core 88 includes a cylindrical first iron core 88a extending in the Z direction and a cylindrical second iron core 88b extending in the Y direction as viewed from the X direction. One end of the first iron core 88a is inserted into a through hole h3 formed between the second movable part 71a and the second movable part 71b, and the other end of the first iron core 88a abuts against the surface of the electromagnet 83 in the -Z direction. The second iron core 88b is disposed on the surface of the second movable part 71b in the +Z direction on the +Y direction side of the second movable part 71b. The elastic member 77b is disposed on the outer circumferential surface of the through hole h3.

[0073] A procedure for moving the light receiving element array 22 in the +Z direction by the second moving mechanism 70c will be described with reference to FIG. 27. FIG. 27 corresponds to FIG. 25. The left side of FIG. 27 shows the second moving mechanism 70c in the normal mode, and the right side of FIG. 27 shows the second moving mechanism 70c in the fault detection mode. In the normal mode, the electromagnet 83 is de-energized. Therefore, as shown in the left side of FIG. 27, the first iron core 88a and the second iron core 88b are disposed at positions separated from each other, and the elastic member 77b is maintained in a state of being extended in the Z direction. This restricts the movement of the light receiving element array 22 in the +Z direction.

[0074] When the electromagnet 83 starts to be energized during the transition from the normal mode to the fault detection mode, as shown on the right side of Fig. 27, the magnetic force of the electromagnet 83 is transmitted to the iron core 88, and the second iron core 88b approaches the first iron core 88a, and the elastic member 77b is deformed (compressed in the Z direction). With this deformation, the first iron core 88a and the second iron core 88b come into contact with each other, and the second movable part 71b is pushed up in the +Z direction, and the center position of the light receiving element array 22 in the Z direction moves in the +Z direction, as shown by the dashed line. Note that, when the light receiving element array 22 is to be returned to its original position, the energization of the electromagnet 83 can be stopped.

[0075] According to the object detection device 10c of the fourth embodiment having the above configuration, the second moving mechanism 70c has the electromagnet 83 and the second movable parts 71a and 71b that move the light receiving element array 22 along the Z direction by adjusting the change in polarity of the electromagnet 83 or the disappearance of the magnetic field, so that the second moving mechanism 70b can have a simpler structure. Note that the first moving mechanism 50 may also be provided with an electromagnet and an iron core as an actuator, similar to the second moving mechanism 70c. In this case, the motor 53 and the screw mechanism 60 are omitted, and an elastic member 77b is provided instead of the elastic member 77.

[0076] E. Fifth embodiment: In the first embodiment, the first region U1 on the light receiving element array 22 is changed by mechanically moving the light receiving element array 22 in the horizontal direction HD and the vertical direction VD by the first moving mechanism 50 and the second moving mechanism 70, a fault detection process is executed for the light receiving elements 220, and the change / movement of the use region is realized in response to the result of the fault detection process. In contrast, in the fifth embodiment, the first region U1 on the light receiving element array 22 is electronically moved by switching the light receiving elements 220 corresponding to the first region U1, and the fault detection process and the change / movement of the use region of the light receiving elements 220 are realized. Note that the configuration of the object detection device according to the fifth embodiment is similar to that of the object detection device 10 according to the first embodiment, except that the light receiving control unit 21 has an execution function for switching the first region U1 by electronic control, and therefore the same reference numerals as those in the first embodiment are used and description thereof is omitted.

[0077] In the first embodiment, for the sake of simplicity, an example in which one light receiving element 220 constitutes one light receiving pixel, that is, the light receiving element and the light receiving pixel are used synonymously. In general, a light receiving pixel is used as a term indicating the minimum unit of light receiving processing, that is, a light receiving unit corresponding to a detection point in an object detection device, and may be constituted by a single light receiving element 220 or a plurality of light receiving elements 220. In the example of FIG. 28, as shown in the enlarged view indicated by the arrow, one light receiving pixel 221 is constituted by four light receiving elements 220, and it can be said that the light receiving element array 22 is constituted by a plurality of light receiving pixels 221. Also, in the example of FIG. 28, the light receiving element NGE is a faulty light receiving element 220.

[0078] The light receiving section 20 in the fifth embodiment, more specifically, the light receiving control section 21, can perform light receiving processing for each light receiving element 220 constituting the light receiving pixel 221 in addition to the light receiving processing for each light receiving pixel 221, and output a first light receiving signal. That is, the light receiving section 20 can switch on / off (receive / do not receive light) the execution of the light receiving processing for each light receiving element 220 constituting each light receiving pixel 221 constituting the first region U1. In the example of FIG. 28, the light receiving section 20 can switch on / off the execution of the light receiving processing for the four light receiving elements 220 constituting the light receiving pixel 221, for example, from the upper left to the upper right and from the lower left to the lower right. As a result, when there is no change in the first light receiving signal when the execution of the light receiving processing is on and off for one light receiving element 220, it can be determined that the light receiving element 220 is malfunctioning, that is, has a failure. The absence of a change in the first light receiving signal means that there is no change in signal intensity or signal value greater than a predetermined difference between when the execution of the light receiving process is on and when it is off. The designation of each light receiving element 220 in the light receiving control unit 21 can be executed by designating an address associated with a light receiving element number that is assigned in advance to each light receiving element 220 or by designating coordinate position information that is assigned in advance, and the on / off of the execution of the light receiving process is realized by connecting / disconnecting an electrical connection between the target light receiving element 220 and a measurement circuit, for example, an adder.

[0079] The failure detection unit 113 executes a failure detection process for each light receiving element shown in FIG. 29. The failure detection process may be executed at predetermined time intervals using ambient light when the object detection device 10 is started. Alternatively, the failure detection process may be executed to identify a light receiving element 220 that has a failure or malfunction when a failure is detected by the mechanical failure detection process in the first embodiment. The failure detection unit 113 executes the first light receiving process using ambient light by turning on the light receiving process execution of all the light receiving elements 220 constituting the first region U1 via the light receiving control unit 21 (step S100). The failure detection unit 113 turns off the light receiving elements 220 constituting the first region U1 on a light receiving element basis, that is, sets the light receiving process execution of one light receiving element 220 to off in accordance with a predetermined order via the light receiving control unit 21 (step S102). The fault detection unit 113 executes a second light receiving process using ambient light using the first region U1 (step S104), and determines whether or not a change has occurred between the amount of light received during the first light receiving process and the amount of light received during the second light receiving process (step S106). More specifically, the fault detection unit 113 determines whether or not a difference greater than a predetermined difference has occurred between the signal value of the first light receiving signal output during the first light receiving process and the signal value of the first light receiving signal obtained during the second light receiving process.

[0080] If the failure detection unit 113 determines that a change has occurred in the amount of received light (step S106: Yes), it determines that the light receiving element 220 for which the light receiving process execution is turned off is normal (step S108) and proceeds to step S112. If the failure detection unit 113 determines that no change has occurred in the amount of received light (step S106: No), it determines that the light receiving element 220 for which the light receiving process execution is turned off is faulty (step S110), stores the light receiving element number and coordinate position information for identifying the light receiving element in the memory 103, and proceeds to step S112. The phenomenon in which the amount of received light does not change depending on whether the light receiving process execution is turned on or off in the target light receiving element 220 means that the target light receiving element 220 is not able to receive ambient light when the light receiving process execution is turned on. The failure detection unit 113 determines whether or not the light receiving process execution off has been completed for all the light receiving elements 220 constituting the first region U1 (step S112), and if the light receiving process execution off has not been completed for all the light receiving elements 220 (step S112: No), it proceeds to step S100, sets the light receiving process execution off for the next light receiving element 220 in step S102, and executes steps S104 to S112. If the light receiving process execution off has been completed for all the light receiving elements 220 (step S112: Yes), the failure detection unit 113 ends this processing routine.

[0081] According to the object detection device 10 of the fifth embodiment, it is possible to electronically detect failures or malfunctions in the first region U1, without having a configuration for mechanically driving the light receiving element array 22. Furthermore, according to the object detection device 10 of the fifth embodiment, it is possible to detect failures or malfunctions in the first region U1 on a light receiving element 220 basis. As a result, it is possible to minimize movement or change of the area of ​​use to avoid failures or malfunctions in the first region U1 when performing the object detection process.

[0082] In the above example, the light receiving process is turned off for each light receiving element 220 over the entire first region U1 to detect a failure of the light receiving element 220. According to this processing procedure, a failure or defect of the light receiving element 220 can be detected with high accuracy. In contrast, the first region U1 may be divided into a predetermined number of regions, and the above failure detection process may be performed for each divided region at different times. Alternatively, the first region U1 may be divided into two, and the light receiving process may be performed using all the light receiving elements 220 in each region, and the same process may be performed for a region with a small amount of received light, and when the number of light receiving pixels 221 reaches a predetermined number, the above failure detection process may be performed for each light receiving element 220. In these cases, the time required for the detection process can be shortened. Furthermore, the first region U1 may be divided into two, and the above failure detection process may be performed for each region, and the division into two and the failure detection process may be repeated for a region with a large amount of change in the amount of received light in each region, i.e., a large integrated value of the difference. By comparing signal values ​​using a binary search, the search efficiency is improved and the detection processing time can be shortened.

[0083] F. Sixth embodiment: The sixth embodiment differs from the first to fourth embodiments in which the first area U1 is moved mechanically in that, when the occurrence of a failure or malfunction in the light receiving element 220 constituting the first area U1 is detected by the failure detection process in the first and fifth embodiments, the first area U1 is electronically moved to a moved use area U11, as shown in Fig. 30, and an object detection process is executed using this moved use area U11. Note that the basic configuration of the object detection device according to the sixth embodiment is similar to the configuration described in the fifth embodiment, and therefore the same reference numerals are used and description thereof will be omitted.

[0084] The failure detection unit 113, upon receiving the result of the failure detection process that the light receiving element NGE constituting the first region U1 is faulty, shifts the control unit 111 to a failure countermeasure mode. The control unit 111 sets the light receiving element 220 corresponding to the moving use region U11 as the light receiving pixel 221 to be used in the first region U1, i.e., as the light receiving element 220. As described above, the light receiving element 220 constituting the light receiving element array 22 is assigned an address for specifying a position in advance. Therefore, by setting the address of the light receiving element 220 corresponding to the moving use region U11 instead of the address of the light receiving element 220 corresponding to the first region U1 as the light receiving element 220 to be used in the object detection process, it is possible to realize the object detection process using the moving use region U11, i.e., the light receiving process for receiving the reflected light corresponding to the irradiation light emitted from the light emitting unit 30. In the example of FIG. 30, in order to avoid the faulty light receiving element NGE, the use region is slid and moved while leaving an overlapping region in the horizontal direction (lateral direction) in the drawing. Depending on the position of the faulty light receiving element NGE, there may be no overlapping area, and if the first area U1 does not extend over the entire vertical (longitudinal) area, a movable use area shifted in the vertical or horizontal as well as vertical directions may be set.

[0085] According to the object detection device 10 of the sixth embodiment, the first region U1 can be changed without using a drive unit for mechanically driving the light receiving element array 22. In addition, since the moving use region U11 is realized by moving the first region U1 horizontally, the use region can be changed while maintaining the continuity between the light receiving elements 220 for light receiving characteristics such as SN. In addition, it is possible to execute the object detection process by executing the same light receiving control as the first region U1. Note that, when the first region U1 is divided into a plurality of regions and the failure detection process is executed, only the region including the failed light receiving element NGE may be moved. In this case, it is possible to suppress the decrease in SN accompanying the movement of the first region U1.

[0086] G. Seventh embodiment: The seventh embodiment differs from the sixth embodiment in that, when the occurrence of a failure or defect in the light receiving element 220 constituting the first area U1 is detected by the failure detection process in the fifth embodiment, the object detection process is executed using a moved use area U12 obtained by electronically moving a part of the use area as shown in Fig. 31. Note that the basic configuration of the object detection device according to the seventh embodiment is similar to the configuration described in the fifth embodiment, and therefore the same reference numerals are used and the description is omitted. Also, in Fig. 31, the first area U1 overlaps with the moved use area U21, and therefore the description is omitted.

[0087] The failure detection unit 113, upon receiving the result of the failure detection process that the light receiving element NGE constituting the first region U1 is broken, shifts the control unit 111 to a failure countermeasure mode. The control unit 111 sets the light receiving element 220 corresponding to the moving use region U12 as the light receiving pixel 221, i.e., the light receiving element 220, to be used in the first region U1. In the seventh embodiment, among the light receiving elements 220 constituting the first region U1, only the broken light receiving element NGE is excluded from the first region U1, and a moving use region U12 in which a part of the first region is moved to include the replacement light receiving element 121 is used. That is, as the light receiving element 220 to be used in the object detection process, the address of the light receiving element 220 corresponding to the moving use region U12, which is obtained by adding the address of the replacement light receiving element 121, is set instead of the address of the broken light receiving element NGE in the first region U1, and the object detection process using the moving use region U12 is realized. The movement of the first region U1 in the seventh embodiment is realized by a combination with a failure detection process capable of identifying a defective light receiving element 220, that is, the failure detection process described in the fifth embodiment.

[0088] According to the object detection device 10 of the seventh embodiment, the first region U1 can be changed without using a driving unit for mechanically driving the light receiving element array 22. In addition, since the moving use region U12 is realized by excluding only the faulty light receiving element NGE from the light receiving elements 220 constituting the use region UI, it is possible to maintain the same SN as when the first region U1 is used. That is, since the first region U1 set as the initial position is set to the region with the best SN in the light receiving element array 22, it is possible to obtain the desired light receiving characteristics by maintaining the light receiving elements 220 other than the faulty light receiving element NGE. Note that the partial region is not limited to the case where there is one faulty light receiving element NGE, and can be similarly applied to the case where there are multiple faulty light receiving elements NGE.

[0089] H. Eighth embodiment: The eighth embodiment differs from the sixth and seventh embodiments in that, when the occurrence of a failure or malfunction in the light receiving element 220 constituting the first region U1 is detected by the failure detection processing in the first and fifth embodiments, the object detection processing is executed using an extended use region U13 that is an electronic extension of the first region U1 as shown in Fig. 32. Note that the basic configuration of the object detection device according to the eighth embodiment is similar to the configuration described in the fifth embodiment, and therefore the same reference numerals are used and the description will be omitted.

[0090] The failure detection unit 113 transitions the control unit 111 to a failure countermeasure mode upon receiving a result of the failure detection process that the light receiving element NGE constituting the first region U1 is faulty. The control unit 111 sets the light receiving element 220 corresponding to the extended use region U13 as the light receiving pixel 221 to be used in the first region U1, i.e., the light receiving element 220. In the eighth embodiment, the extended use region U13, which includes the first region U1 together with the light receiving element NGE identified as faulty and is extended in the horizontal direction, is used. That is, as the light receiving element 220 to be used in the object detection process, the address of the light receiving element 220 corresponding to the extended use region U13, which is obtained by adding the address of the light receiving element 220 extended as the extended use region U13 to the address of the light receiving element 220 constituting the first region U1, is set, and the object detection process using the extended use region U13 is realized.

[0091] According to the object detection device 10 of the eighth embodiment, the first region U1 can be changed without using a driving unit for mechanically driving the light receiving element array 22. In addition, since the extended use region U13 is realized by expanding the first region U1, it is possible to compensate for the decrease in signal strength caused by the absence of a faulty light receiving element 220. Note that, when the first region U1 is divided into a plurality of regions and the fault detection process is executed, only the region including the faulty light receiving element NGE may be expanded. In this case, it is possible to suppress the generation of noise caused by the expansion of the first region U1.

[0092] I. Other embodiments: (1) In each of the above embodiments, the third region U3 is located in the +Z direction of the first region U1, but may be located in the -Z direction of the first region U1. In this case, in the second moving mechanisms 70, 70a, 70b, and 70c, the second movable part 71b is moved in the -Z direction relative to the second movable part 71a, so that the use region can be moved from the first region U1 to the third region U3. In addition, when shifting from the failure detection mode to the failure countermeasure mode, the use region is moved from the third region U3 back to the first region U1 and then to the second region U2, but the process of returning it to the first region U1 may be omitted. That is, the second region U2 may be a region obtained by translating the third region U3 in the X direction.

[0093] (2) In the first embodiment, in order to remove backlash (position error caused by a gap between components that transmit driving force) of the screw mechanism, the first moving mechanism 50 and the second moving mechanism 70 may be pressed against each other using an elastic member. Also, the guides 55 and 75 may be omitted. In this case, the screw mechanisms 60 and 80 may be used to maintain the parallel state of the light receiving lens 23 and the light receiving element array 22 in the X direction and the Z direction.

[0094] (3) In each of the above embodiments, when it is determined that the light receiving element 220 in the first region U1 may be malfunctioning or is malfunctioning, an object may be detected using a sensor other than the distance measuring device 200, such as an imaging device or a LIDAR other than the distance measuring device 200. In addition, a user of the object detection device 10, such as a passenger of the vehicle on which the object detection device 10 is mounted or a manager of the vehicle, may be notified.

[0095] (4) In the third and fourth embodiments described above, the first moving mechanism 50 of the first embodiment is used as the first moving mechanism, but instead, the first moving mechanism 50a of the second embodiment may be used. Note that the first moving mechanisms 50, 50a and the second moving mechanisms 70, 70b, 70c, 70d in each embodiment may be used in any combination.

[0096] (5) In the above embodiments, the possibility of failure of the light receiving element 220 or the failure of the light receiving element 220 is detected based on the presence or absence of a black line appearing in the ambient light image, i.e., the presence or absence of a pixel row whose luminance value is equal to or less than a first predetermined value. However, instead of or in addition to the presence or absence of a black line, the presence or absence of a white line, i.e., the presence or absence of a pixel row forming a bright line whose luminance value is equal to or greater than a second predetermined value different from the first predetermined value, may be detected. In this case, it is sufficient to detect whether a pixel group whose luminance value is 255 is arranged along the X direction in the image data of the ambient light image. In addition, the luminance value is not limited to 255, and a value equal to or greater than a luminance value that is a reference value for high luminance may be used. Furthermore, when the luminance difference between the luminance value of a pixel row forming a black line or white line and the luminance value of a pixel row adjacent to the pixel row forming the black line or white line is equal to or greater than a predetermined difference value, the presence of a black line or white line, i.e., the failure of the light receiving element 220 may be confirmed. For example, when it is very bright, the ambient light image becomes bright overall, and at night, the ambient light image becomes dark overall. Therefore, if the only determination condition is that the luminance value of the pixel row is equal to or less than a first predetermined value or equal to or more than a second predetermined value, a malfunction of the light receiving element 220 may be determined even when the ambient light image is bright or dark overall. Therefore, by using the difference in luminance value between the target pixel row that is equal to or less than a first predetermined value or equal to or more than a second predetermined value and the pixel row adjacent to the target pixel row as an additional determination condition, the accuracy of distinguishing between black and white lines can be improved.

[0097] (6) In each of the above embodiments, when a black line is detected, the control unit 111 determines the possibility of a malfunction and changes the usage area from the first area U1 to the third area U3, and the malfunction detection unit 113 determines whether the position of the detected black line has moved, thereby determining a malfunction of the light receiving element 220. Alternatively, the malfunction detection unit 113 may determine a malfunction of the light receiving element 220 when a pixel row whose luminance value is equal to or less than a first predetermined value or equal to or more than a second predetermined value is detected consecutively at the same position in a plurality of acquired ambient light images.

[0098] (7) Each unit of the control unit and the like described in the present disclosure and its method may be realized by a dedicated computer provided by configuring a processor and a memory programmed to execute one or more functions embodied in a computer program. Alternatively, each unit of the control unit and the like described in the present disclosure and its method may be realized by a dedicated computer provided by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the control unit and its method described in the present disclosure may be realized by one or more dedicated computers configured by a combination of a processor and a memory programmed to execute one or more functions and a processor configured with one or more hardware logic circuits. In addition, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions executed by a computer.

[0099] The present disclosure is not limited to the above-mentioned embodiment, and can be realized in various configurations without departing from the spirit of the present disclosure. For example, the technical features in the embodiments corresponding to the technical features in each aspect described in the Summary of the Invention column can be appropriately replaced or combined to solve some or all of the above-mentioned problems or to achieve some or all of the above-mentioned effects. Furthermore, if the technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0100] 10: object detection device, 20: light receiving unit, 113: fault detection unit, 115: image acquisition unit, 220: light receiving element, IL: irradiated light, Img1: ambient light image, RL: incident light, Ar1, Ar2: area, U1: first area

Claims

1. An object detection device (10, 10a, 10b, 10c) for detecting an object, a light receiving unit (20) having a light receiving surface on which a plurality of light receiving elements (220) capable of receiving incident light (RL) including reflected light of emitted irradiation light (IL) are arranged in a planar manner, the light receiving unit (20) defining a predetermined use area in a usable area (Ar1, Ar2) on the light receiving surface as a first area (U1) and a third area (U3) different from or partially overlapping the first area, and outputs a first light receiving signal corresponding to a light receiving state of the light receiving elements in the first area and a third light receiving signal corresponding to a light receiving state of the light receiving elements in the third area; an image acquisition unit (115) that acquires a first ambient light image (Img1) indicating a received light intensity of ambient light using the first light receiving signal, and acquires a third ambient light image (Img3) indicating a received light intensity of ambient light using the third light receiving signal; a failure detection unit (113) that detects a failure of the light receiving element in the first region by using the first ambient light image and the third ambient light image, the failure detection unit detecting a failure of the light receiving element in the first region when a position of a pixel group in the first ambient light image whose luminance value is equal to or less than a first predetermined value or equal to or more than a second predetermined value different from the first predetermined value moves in the third ambient light image; An object detection device comprising:

2. The object detection device according to claim 1 , the light receiving unit is capable of outputting the first light receiving signal in units of divided regions obtained by dividing the first region into a plurality of predetermined regions, The failure detection unit detects a failure of the light receiving element in the first region by using the first light receiving signal outputted in units of the divided regions.

3. The object detection device according to claim 1 , the light receiving unit is capable of outputting the first light receiving signal in units of the light receiving elements in the first region, The failure detection unit detects a failure of the light receiving element in the first region by using the first light receiving signal outputted on a unit basis of the light receiving element.

4. The object detection device according to any one of claims 1 to 3, an object detection unit (117) that detects the object using a light receiving signal output by the light receiving unit; a first moving mechanism (50) that moves the use area to a second area (U2) located in a first direction (HD) relative to the first area; A control unit (111) that controls the driving of the first moving mechanism; Further equipped with the light receiving unit outputs a second light receiving signal corresponding to a light receiving state of the light receiving element in the second region; the object detection unit detects the object by using the second light receiving signal when a failure of the light receiving element in the first area is detected. Object detection device.

5. The object detection device according to any one of claims 1 to 4, the failure detection unit detects that the light receiving element in the first region may be faulty when the pixel group is arranged along a first direction in the image data of the first ambient light image; Object detection device.

6. The object detection device according to claim 5 , a second moving mechanism (70) that moves the use area to the third area (U3) located in a second direction (VD) perpendicular to the first direction relative to the first area; A control unit that controls driving of the second moving mechanism; Further equipped with when it is detected that the light receiving element in the first region may be malfunctioning, the image acquisition unit acquires the third ambient light image using the third light receiving signal; the failure detection unit detects that the light receiving element in the first region is faulty when, in the acquired image data of the third ambient light image, the group of pixels moves in the second direction with respect to an original pixel position as the group of pixels moves from the first region to the third region of the usage region; Object detection device.

7. The object detection device according to claim 4, The first moving mechanism is A screw mechanism (60); A motor (53) for driving the screw mechanism; a first movable portion (51 a, 51 b) that moves the light receiving surface along the first direction by driving the screw mechanism; An object detection device comprising:

8. The object detection device according to claim 4, The first moving mechanism is a lock mechanism (64) that restricts movement of the light receiving surface in the first direction; A drive unit (63) for controlling switching between a locked state and an unlocked state of the lock mechanism; a first movable portion (51 a, 51 b) that moves the light receiving surface along the first direction when the lock mechanism is in the released state; An object detection device comprising:

9. The object detection device according to claim 4, The first moving mechanism is A piezoelectric body; a first movable portion (51 a, 51 b) that moves the light receiving surface along the first direction when the piezoelectric body is applied; An object detection device comprising:

10. The object detection device according to claim 4, The first moving mechanism is An electromagnet, a first movable portion (51 a, 51 b) that moves the light receiving surface along the first direction by adjusting the change in polarity of the electromagnet or the disappearance of the magnetic field; An object detection device comprising:

11. The object detection device according to claim 6, The second moving mechanism is A screw mechanism (80); A motor (73) for driving the screw mechanism; a second movable portion (71 a, 71 b) that moves the light receiving surface along the second direction by driving the screw mechanism; An object detection device comprising:

12. The object detection device according to claim 6, The second moving mechanism is a lock mechanism (84) that restricts movement of the light receiving surface in the second direction; A drive unit (83) for controlling switching between a locked state and an unlocked state of the lock mechanism; a second movable portion that moves the light receiving surface along the second direction when the lock mechanism is in the released state; An object detection device comprising:

13. The object detection device according to claim 6, The second moving mechanism is A piezoelectric body (87); a second movable portion (71 a, 71 b) that moves the light receiving surface along the second direction when the piezoelectric body is applied; An object detection device comprising:

14. The object detection device according to claim 6, The second moving mechanism is An electromagnet (83); a second movable portion (71 a, 71 b) that moves the light receiving surface along the second direction by adjusting the change in polarity of the electromagnet or the disappearance of the magnetic field; An object detection device comprising:

15. The object detection device according to any one of claims 1 to 3, further comprising: An object detection unit (117) that detects the object using a light receiving signal output by the light receiving unit, the light receiving unit includes a light receiving control unit that moves the use area in at least one of a first direction and a second direction perpendicular to the first direction to receive the incident light, When a failure of the light receiving element in the first area is detected, the light receiving control unit moves the use area to a second area (U2) located in a first direction (HD) relative to the first area to receive the incident light, the light receiving unit outputs a second light receiving signal corresponding to a light receiving state of the light receiving element in the second area, and the object detection unit detects the object using the second light receiving signal. Object detection device.

16. The object detection device according to any one of claims 1 to 3, further comprising: An object detection unit (117) that detects the object using a light receiving signal output by the light receiving unit, the light receiving unit includes a light receiving control unit that expands the use area in at least one of a first direction and a second direction perpendicular to the first direction to receive the incident light, When a failure of the light receiving element in the first area is detected, the light receiving control unit receives the incident light by a second area (U2) that is an extension of the usage area in a first direction (HD) relative to the first area, the light receiving unit outputs a second light receiving signal according to a light receiving state of the light receiving element in the second area, and the object detection unit detects the object using the second light receiving signal. Object detection device.

17. The object detection device according to claim 3, further comprising: An object detection unit (117) that detects the object using a light receiving signal output by the light receiving unit, the light receiving unit includes a light receiving control unit that moves a part of the use area corresponding to the light receiving element in at least one of a first direction and a second direction perpendicular to the first direction to receive the incident light, When a failure of the light receiving element in the first area is detected, the light receiving control unit moves the part of the usage area to a second area (U2) located in a first direction (HD) relative to the first area to receive the incident light, the light receiving unit outputs a second light receiving signal according to a light receiving state of the light receiving element in the second area, and the object detection unit detects the object using the second light receiving signal. Object detection device.

18. 1. A method for detecting a fault in an object detection device, comprising: a light receiving surface having a plurality of light receiving elements arranged in a planar shape, the light receiving surface being capable of receiving incident light including reflected light of the emitted irradiation light, the light receiving surface being provided with a first region and a third region different from or partially overlapping the first region, the first region being one of the plurality of predetermined use regions, and the third region being provided with a first light receiving signal corresponding to a light receiving state of the light receiving elements in the first region and a third light receiving signal corresponding to a light receiving state of the light receiving elements in the third region; obtaining a first ambient light image indicating a received light intensity of ambient light using the first light receiving signal, and obtaining a third ambient light image indicating a received light intensity of ambient light using the third light receiving signal; using the first ambient light image and the third ambient light image, detecting a failure of the light receiving element in the first region when a position of a pixel group in the first ambient light image, the pixel group having a luminance value equal to or less than a first predetermined value or equal to or more than a second predetermined value different from the first predetermined value, moves in the third ambient light image; A method for detecting faults in an object detection device.

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