Object detection device and method for detecting failure of object detection device

Abstract

An object detection device (10, 10a, 10b, 10c) for detecting an object comprises: a light receiving unit (20) having a light receiving surface formed by a plurality of light receiving elements (220) arranged in a planar shape and capable of receiving incident light (RL), wherein the incident light includes reflected light of emitted irradiation light (IL), a pre-set use area in a useable area (Ar1, Ar2) of the light receiving surface is used as a first area (U1), and a first light receiving signal corresponding to the light receiving state of the light receiving element in the first area is output; an image acquisition unit (115) using the first light receiving signal to acquire an ambient light image (Img1) indicating the light receiving intensity of ambient light; and a fault detection unit (113) using the ambient light image to detect a fault of the light receiving element in the first area.

Description

[0001] Cross-references between related applications

[0002] This application claims priority based on Japanese Patent Application No. 2020-124176 filed on July 21, 2020 and Japanese Patent Application No. 2021-107544 filed on June 29, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to an object detection device. Background Art

[0004] Various technologies have been proposed for detecting failures in object detection devices such as imaging devices and optical ranging devices. For example, International Publication No. 2014 / 148161 detects failures in an imaging device by comparing the brightness of each pixel between a current frame image and a previous frame image that is closer in time to the current frame image.

[0005] However, the technology described in International Publication No. 2014 / 148161 requires camera images obtained in the past, so there is a possibility that the load on the object detection device will increase or the responsiveness will decrease. In addition, since the presence or absence of a fault is detected for each pixel of the camera image, it is possible that the occurrence of the fault cannot be detected with good accuracy. This problem also occurs when the object detection device is composed of an optical ranging device (lidar), and when detecting a fault in a light receiving element that receives reflected light of the emitted irradiated light. Therefore, a technology for detecting a fault in an object detection device with good accuracy is desired. Summary of the Invention

[0006] According to one technical solution of the present disclosure, an object detection device for detecting an object is provided. The object detection device comprises: a light receiving unit having a light receiving surface having a plurality of light receiving elements arranged in a planar shape and capable of receiving incident light, the incident light including reflected light of emitted irradiation light; the light receiving unit, with a predetermined usable area within a usable area of ​​the light receiving surface as a first area, outputting a first light receiving signal corresponding to the light receiving state of the light receiving elements within the first area; an image acquisition unit, using the first light receiving signal, acquiring an ambient light image representing the received light intensity of ambient light; and a fault detection unit, using the ambient light image, detecting a fault in the light receiving elements within the first area.

[0007] According to the object detection device of this technical solution, an ambient light image is obtained by using a first light receiving signal corresponding to the light receiving state of the light receiving elements in the first area of ​​a light receiving surface on which a plurality of light receiving elements are arranged in a planar manner, and a fault of the light receiving elements in the first area is detected using the obtained ambient light image. Therefore, the fault of the light receiving elements can be detected with good accuracy while reducing the load on the object detection device.

[0008] The present disclosure can be implemented in various forms, for example, as a failure detection device for an object detection device, a failure detection method for an object detection device, a computer program for implementing these devices or methods, or a storage medium storing the computer program. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The above-mentioned object and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings.

[0010] Figure 1 It is an explanatory diagram showing a schematic configuration of an object detection device.

[0011] Figure 2 It is an explanatory diagram schematically showing the structure of a light-receiving element array.

[0012] Figure 3 This is an explanatory diagram showing an example of a usage area.

[0013] Figure 4 This is a block diagram showing the functional structure of the control device.

[0014] Figure 5 It is a top view of the first moving mechanism and the second moving mechanism.

[0015] Figure 6 It is a side view of the first moving mechanism and the second moving mechanism.

[0016] Figure 7 It means along Figure 5 Cross-sectional view of the cross section along line 7-7.

[0017] Figure 8 It means along Figure 6 A cross-sectional view of the cross section along line 8-8.

[0018] Figure 9 This is a flowchart showing the processing procedure of the fault detection process.

[0019] Figure 10 This is an explanatory diagram showing an example of an ambient light image obtained in each operation mode.

[0020] Figure 11It is a plan view showing the first moving mechanism and the second moving mechanism according to the second embodiment.

[0021] Figure 12 It is a side view showing the first moving mechanism and the second moving mechanism of the second embodiment.

[0022] Figure 13 It means along Figure 11 A cross-sectional view of the cross section along line 13-13.

[0023] Figure 14 It means along Figure 12 A cross-sectional view of the cross section along line 14-14.

[0024] Figure 15 It is an explanatory diagram schematically showing a state in which the second movable portion moves.

[0025] Figure 16 It is an explanatory diagram schematically showing a state in which the second movable portion moves.

[0026] Figure 17 It is an explanatory diagram schematically showing the state of movement of the lock pin.

[0027] Figure 18 It is a plan view of the first moving mechanism and the second moving mechanism in the third embodiment.

[0028] Figure 19 It is a side view of the first moving mechanism and the second moving mechanism in the third embodiment.

[0029] Figure 20 It means along Figure 18 A cross-sectional view of the cross section taken along line 20-20.

[0030] Figure 21 It means along Figure 19 A cross-sectional view of the section taken along line 21-21.

[0031] Figure 22 It is an explanatory diagram schematically showing a state in which the second movable portion moves.

[0032] Figure 23 It is a plan view of the first moving mechanism and the second moving mechanism in the fourth embodiment.

[0033] Figure 24 It is a side view of the first moving mechanism and the second moving mechanism in the fourth embodiment.

[0034] Figure 25 It means along Figure 23 Cross-sectional view of the cross section along line 25-25.

[0035] Figure 26 It means along Figure 24 A cross-sectional view of the section along line 26-26.

[0036] Figure 27 It is an explanatory diagram schematically showing a state in which the second movable portion moves.

[0037] Figure 28 This is an explanatory diagram showing the concept of failure detection according to the fifth embodiment.

[0038] Figure 29 This is a flowchart showing the processing procedure of the fault detection process according to the fifth embodiment.

[0039] Figure 30 It is an explanatory diagram showing a modified form of the use area related to the sixth embodiment.

[0040] Figure 31 It is an explanatory diagram showing a modified form of the usage area related to the seventh embodiment.

[0041] Figure 32 It is an explanatory diagram showing a modified form of the use area related to the eighth embodiment. DETAILED DESCRIPTION

[0042] A. First embodiment:

[0043] A1.Device structure:

[0044] like Figure 1 As shown, an object detection device 10 as one 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 existing around the vehicle by acquiring information about the surroundings of the vehicle, such as the distance to the object targets around the vehicle. Figure 1 The X-axis, Y-axis, and Z-axis are shown as three mutually orthogonal axes. The X-axis is parallel to the horizontal direction HD, and the Z-axis is parallel to the vertical direction VD. The X-axis, Y-axis, and Z-axis shown in other figures correspond to Figure 1 The X-axis, Y-axis, and Z-axis of the present invention are shown in Figure 1. When determining the direction, the positive direction is set to "+" and the negative direction is set to "-", and both positive and negative signs are used in the direction expression. In addition, the X direction is equivalent to the subordinate concept of the first direction of the present invention, and the Z direction is equivalent to the subordinate concept of the second direction of the present invention. In addition, the +X direction is equivalent to the subordinate concept of one side of the first direction, and the +Z direction is equivalent to the subordinate concept of one side of the second direction.

[0045] The distance measuring device 200 is a LiDAR (Light Detection and Ranging) system. The distance measuring device 200 emits irradiation light IL and receives reflected light from a target object, thereby detecting the target object's distance and shape relative to the vehicle. In addition to receiving reflected light from the target object, the distance measuring device 200 also receives ambient light (hereinafter referred to as "background light"), such as sunlight, streetlights, headlights of other vehicles, and light reflected from these objects. The distance measuring device 200 identifies the light received after removing the background light as reflected light from the object and calculates the time from the application of the irradiation light IL to the reception of the reflected light, i.e., the time of flight (TOF) of the light, as the distance to the object.

[0046] The distance measuring device 200 includes a light receiving unit 20, a light emitting unit 30, a scanning mirror 42, a 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. The light emitting unit 30 emits illumination light IL and the light receiving unit 20 receives incident light RL, each divided into multiple unit scanning angles SC. This allows for the acquisition of detection points across the entire scanning angle range SR, achieving distance measurement. The unit scanning angle SC defines the resolution of the distance measuring device 200, or the resolution of the distance measurement results obtained by the distance measuring device 200. As the unit scanning angle SC decreases, that is, as the number of detection points increases, the resolution and resolution in the horizontal direction HD increase. The acquisition of detection points by the distance measuring device 200, i.e., the light emission and light reception processing, is performed when the scanning angle range SR is scanned in a single direction or when the scanning angle range SR is scanned in a bidirectional, reciprocating manner. Alternatively, 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.

[0047] The light receiving unit 20 includes a light receiving element array 22 and a light receiving control unit 21. Figure 1 The light receiving lens 23 (not shown) 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 irradiated from the light emitting unit 30, such as the light receiving amount / light receiving intensity.

[0048] like Figure 2As shown, the light receiving element array 22 has a light receiving surface in which a plurality of light receiving elements 220 are arranged in the vertical and horizontal directions, i.e., in two dimensions. The light receiving element array 22 is a light sensor capable of receiving incident light, and each light receiving element is constituted by a SPAD (Single Photon Avalanche Diode) or other photodiodes. In this embodiment, a plurality of use areas are pre-set for the light receiving element array 22. The use area is exclusively selected corresponding to the operation mode of the distance measuring device 200, and the light receiving processing is performed using the light receiving elements 220 in the selected use area. The operation mode includes: a "normal mode" for performing normal operation of the distance measuring device 200, a "fault detection mode" for detecting a fault in the light receiving element 220 in the normal mode, and a "fault countermeasure mode" for performing normal operation using a light receiving element 220 in which no fault is detected when a fault in the light receiving element 220 is detected in the fault detection mode.

[0049] like Figure 2 As shown, 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 used in normal mode and fault detection mode. The second usable area Ar2 is used in fault countermeasure mode. In other words, the first usable area Ar1 is used for normal light reception processing, while the second usable area Ar2 is a backup area used for light reception processing in the event of a fault in the first usable area Ar1.

[0050] As in Figure 3 As indicated by the shading in the upper portion of the figure, the first area U1 within the first usable area Ar1 is used in normal mode. The first area U1 is composed of a plurality of light-receiving elements 220 within a predetermined range within the first usable area Ar1. The light-receiving unit 20 outputs a light-receiving signal (hereinafter referred to as the "first light-receiving signal") corresponding to the light-receiving state of the light-receiving elements 220 within the first area U1.

[0051] As in Figure 3 As indicated by the shading on the left side of the lower section, the third area U3 is used in the fault detection mode. The third area U3 is the area obtained by parallel shifting the first area U1 in the +Z direction. It may partially overlap with the first area U1, or it may not overlap with the first area U1. Alternatively, the third area U3 may be the area obtained by parallel shifting the first area U1 in the -Z direction. The light receiving unit 20 outputs a light reception signal (hereinafter referred to as the "third light reception signal") corresponding to the light reception state of the light receiving element 220 within the third area U3.

[0052] As in Figure 3As indicated by the shading on the right side of the lower section, the second area U2 is used in the fault countermeasure mode. The second area U2 is the area obtained by parallel shifting the first area U1 in the +X direction. The light receiving unit 20 outputs a light reception signal (hereinafter referred to as the "second light reception signal") corresponding to the light reception state of the light receiving element 220 in the second area U2.

[0053] The distance measuring device 200 includes a mechanism for changing the areas U1, U2, and U3. This mechanism is controlled by switching the operating modes, thereby enabling light reception processing using the areas U1, U2, and U3 corresponding to each operating mode. The mechanism for changing the areas U1, U2, and U3 will be described later.

[0054] The light receiving control unit 21 performs light receiving processing to output an incident light intensity signal corresponding to the amount of incident light or the incident light intensity incident on the light receiving element 220 in the areas U1, U2, and U3, using the unit scanning angle SC at which the light emitting unit 30 emits light.

[0055] The light-emitting unit 30 includes a light-emitting control unit 31, a light-emitting element 32, and a collimating lens, and emits irradiation light IL once or multiple times discretely per unit scanning 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-emitting control unit 31 drives the light-emitting element 32 with a drive signal having a pulse drive waveform, based on a light-emitting control signal input from the control device 100 for instructing the light-emitting element 32 to emit light per unit scanning angle SC, thereby emitting infrared laser light. The infrared laser light emitted from the light-emitting unit 30 is reflected by the scanning mirror 42 and emitted toward the outside of the distance measuring device 200, that is, toward the range where the object is desired to be detected.

[0056] The motor 40 is equipped with a motor driver (not shown). A rotation angle sensor 41 is provided in the motor 40 to detect the rotation angle of the motor 40. The motor driver receives a rotation angle indication signal from the control device 100, which is input from the rotation angle sensor 41. The motor driver changes the voltage applied to the motor 40 to control the rotation angle of the motor 40. The motor 40 is, for example, an ultrasonic motor, a brushless motor, or a brush motor, and is equipped with a known mechanism for reciprocating within a scanning angle range SR. A scanning mirror 42 is attached to the front end of the output shaft of the motor 40.

[0057] The scanning mirror 42 is a reflector, i.e., a mirror, that scans the irradiation light IL emitted from the light emitting unit 30 in the horizontal direction HD. It is driven back and forth by the motor 40 to scan within a scanning angle range SR in the horizontal direction HD. The scanning mirror 42 scans the detection light and receives the reflected light within a scanning angle range such as 120 degrees or 180 degrees. In the case of a single light emitting element or in the case of being unable to emit detection light in the entire vertical direction VD, the scanning mirror 42 can also scan in the vertical direction VD in addition to the horizontal direction HD, i.e., change the scanning position in the vertical direction VD. In order to scan in the horizontal direction HD and the vertical direction VD, the scanning mirror 42 can be a multifaceted mirror, such as a multifaceted reflector, or a single-sided mirror having a mechanism for swinging it in the vertical direction VD, or another single-sided mirror having a mechanism for swinging it in the vertical direction VD. Alternatively, the scanning mirror 42 may be rotationally driven by the motor 40 to perform rotational scanning. In this case, the light emitting unit 30 and the light receiving unit 20 may simply emit light and receive light in accordance with the scanning angle range SR.

[0058] The irradiation light IL emitted from the light emitting unit 30 is reflected by the scanning mirror 42 and scanned across the scanning angle range SR in the horizontal direction HD in units of the unit scanning angle SC. The reflected light of the irradiation light IL after being reflected by the target object is reflected by the scanning mirror 42 toward the light receiving unit 20 and enters the light receiving unit 20 at each unit scanning angle SC. The unit scanning angle SC at which the light receiving process is performed is increased sequentially, and as a result, scanning for light receiving process across the desired scanning angle range SR can be performed. In addition, in the case where the detection light cannot be irradiated to the entire area of ​​the 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 can be rotated by the motor 40 together with the scanning mirror 42, or can be separate from the scanning mirror 42 and not rotated by the motor 40. Furthermore, instead of the scanning mirror 42 , a plurality of light emitting elements 32 and a light receiving element array 22 arranged in an array may be provided, and a structure may be adopted in which laser light is directly irradiated to the outside in sequence and reflected light is directly received.

[0059] like Figure 4As shown, 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 via a bus 105 for bidirectional communication. The memory 103 includes a ROM, a RAM, and an EEPROM. The input / output interface 101 is connected to the light emission control unit 31, the light receiving control unit 21, the motor 40, and the rotation angle sensor 41 via control signal lines. A light emission control signal is sent to the light emission control unit 31, and a light receiving control signal is sent to the light receiving control unit 21. The light receiving control signal instructs light receiving processing for obtaining ambient light or light receiving processing for object detection corresponding to the transmission of the light emission control signal, and the light receiving signal is received from the light receiving control unit 21. A rotation angle instruction signal is sent to the motor 40, and a rotation angle signal is received from the rotation angle sensor 41.

[0060] The CPU 110 expands and executes the programs stored in the memory 103 , thereby functioning as a control unit 111 , a fault detection unit 113 , an image acquisition unit 115 , and an object detection unit 117 .

[0061] The control unit 111 controls the overall operation of the object detection device 10. The fault detection unit 113 detects faults in the light receiving element 220 within the first usable area Ar1, more specifically, within the first area U1. The image acquisition unit 115 acquires an ambient light image representing the intensity of ambient light. The object detection unit 117 uses the light reception signal output by the light receiving unit 20 to detect objects around the vehicle.

[0062] use Figure 5 、 Figure 6 、 Figure 7 and Figure 8 , the mechanism for changing the areas U1, U2, and U3 will be described. 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 the horizontal direction HD, for example, the +X direction. In this embodiment, in the fault countermeasure mode, it is used to move the use area from the first area U1 to the second area U2. The second moving mechanism 70 is a mechanism for moving the light receiving element array 22 in the +Z direction, for example. In this embodiment, in the fault countermeasure mode, it is used to move the use area from the first area U1 to the third area U3.

[0063] like Figure 5 and Figure 6As shown, the first moving mechanism 50 and the second moving mechanism 70 are arranged in this order from the -Y direction side, including the light receiving lens 23, the light receiving element array 22, the second moving mechanism 70, and the first moving mechanism 50, and are fixed to the base member 91. The light receiving element array 22 is mounted on the surface of the second moving mechanism 70 on the -Y direction side.

[0064] like Figure 5 、 Figure 6 、 Figure 7 and Figure 8 As shown, the first movable 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 components for parallel movement of the light receiving element array 22 relative to the light receiving lens 23 in the X direction. The -Y direction surface of the first movable part 51b is fixed to the +Y direction surface of the second movable mechanism 70. The first movable part 51b is driven by the screw mechanism 60 to move in the X direction. As the first movable part 51b moves in the X direction, the second movable mechanism 70 and the light receiving element array 22 move in the X direction in conjunction with the first movable part 51b.

[0065] The motor 53 is mounted on the surface of the first movable portion 51a on the +X direction side, and rotates the screw mechanism 60 in response to the control signal from the control unit 111. The guide 55 guides the movement of the first movable portion 51b in the X direction while maintaining the parallel state of the light receiving element array 22 and the light receiving lens 23 in the X direction. Figure 6 As shown, since the guide 55 has a trapezoidal shape with the −Y direction side as the base, it is possible to suppress the shaking of the light receiving element array 22 and the light receiving lens 23 .

[0066] The screw mechanism 60 includes a male thread 61 and a female thread 62. In normal mode, the male thread 61 and the female thread 62 engage. In fault response mode, when the motor 53 rotates the male thread 61, the engagement between the male thread 61 and the female thread 62 is released, and the first movable portion 51b moves in the X direction. In this case, the male thread 61 is rotated until the movement of the first movable portion 51b reaches a predetermined amount. The predetermined amount of movement is, for example, several millimeters.

[0067] The elastic member 57 covers the outer peripheral surface of the end portion on the −X direction side of the male screw 61. The elastic member 57 deforms (expands) 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 or silicone rubber.

[0068] The second moving mechanism 70 has the same structure as the first moving mechanism 50. Specifically, Figures 5 to 8As shown, the second moving mechanism 70 includes a pair of second movable parts 71 a and 71 b , a motor 73 , a guide 75 , a screw mechanism 80 , and an elastic member 77 .

[0069] The second movable portions 71a and 71b are components for parallel movement of the light receiving element array 22 in the Z direction relative to the light receiving lens 23. The second movable portion 71b is driven to move in the Z direction by the screw mechanism 80. As the second movable portion 71b moves in the Z direction, the light receiving element array 22 moves in the Z direction in conjunction with the second movable portion 71b.

[0070] The motor 73 is mounted on the +X-direction surface of the second movable portion 71a and rotationally drives the screw mechanism 80 in response to a control signal from the control unit 111. The guide 75 guides the Z-direction movement of the second movable portion 71b while maintaining the Z-direction parallelism between the light-receiving element array 22 and the light-receiving lens 23. Like the guide 55 of the first moving mechanism 50, the guide 75 has a trapezoidal shape with its base oriented in the -Y direction. This prevents any shaking of the light-receiving element array 22 and the light-receiving lens 23.

[0071] The screw mechanism 80 includes a male thread 81 and a female thread 82. In normal mode, the male thread 81 engages with the female thread 82. In fault response mode, when the motor 73 rotates the male thread 81, the engagement between the male and female threads 81 and 82 is released, allowing the second movable portion 71b to move in the Z direction. In this case, the male thread 81 rotates until the second movable portion 71b reaches a predetermined movement amount. The predetermined movement amount is, for example, several tens of micrometers.

[0072] The elastic member 77 covers the outer peripheral surface of the end portion on the −Z direction side of the male screw 61. The elastic member 77 deforms (expands) 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 or silicone rubber.

[0073] A2. Fault detection and processing:

[0074] Figure 9 The fault detection process shown is repeatedly executed at predetermined time intervals 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 the first light reception signal output by the light reception process using the light receiving element 220 within the first area U1.

[0075] In step S15, the fault detection unit 113 determines whether a black line is detected in the ambient light image. Figure 10In the image data of the ambient light image Img1 in normal mode shown on the left side of FIG, a black line BL, i.e., a dark line, is displayed along the X direction. More specifically, the fault detection unit 113 determines whether a group of pixels with a luminance value of 0 (zero) is arranged along the X direction in the image data of the ambient light image Img1. In other words, whether there is a column of pixels with a luminance value of 0 that forms a row in the scanning direction. The luminance value is not limited to zero; a value below the luminance value, which serves as a low-luminance reference value, may also be used.

[0076] If a black line is detected in the ambient light image (step S15: Yes), the fault detection unit 113 determines that the light receiving element 220 in the first area U1 may have failed, and in step S20, the control unit 111 switches to a fault detection mode. Specifically, in step S21, the control unit 111 controls the second movable mechanism 70 to change the operating area from the first area U1 to the third area U3. The control unit 111 drives the motor 73 to rotate the screw mechanism 80, thereby moving the second movable portion 71b in the +Z direction or the -Z direction.

[0077] 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 the third light reception signal outputted by the light reception process using the light receiving element 220 in the third area U3.

[0078] In step S30, the fault detection unit 113 determines whether the position of the black line detected in step S15 has moved. Specifically, the fault detection unit 113 determines whether the position of the black line detected in step S15 has moved. Figure 10 In the image data of the ambient light image Img2 in the fault detection mode shown in the center of FIG, whether the position of the black line BL has moved to the +Z direction side or the -Z direction side as the use area is changed from the first area U1 to the third area U3. In other words, the fault detection unit 113 determines whether the pixel group with a luminance value of 0 (zero) detected in 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 side relative to the pixel position in the image data of the ambient light image Img1.

[0079] When it is determined that the position of the black line has moved (step S30: yes), the fault detection unit 113 deems that the light receiving element 220 in the first area U1 has failed, and in step S35, the control unit 111 is transferred to the fault countermeasure mode. Specifically, in step S36, the control unit 111 changes the use area from the third area U3 to the second area U2 by controlling the first moving mechanism 50 and the second moving mechanism 70. 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, so that the use area returns from the third area U3 to the first area 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, so that the use area moves from the first area U1 to the second area U2. As a result, in Figure 10 The black line BL is no longer detected in the image data of the ambient light image Img3 in the fault countermeasure mode shown on the right side of FIG. Then, in the object detection process executed by the object detection unit 117 , the light receiving element 220 in the second area U2 is used.

[0080] If the black line position is determined to be unchanged in step S30 (step S30: No), the fault detection unit 113 assumes that the light receiving element 220 in the first area U1 is not faulty and, in step S40, causes the control unit 111 to switch to normal mode. Specifically, in step S41, the control unit 111 controls the second moving mechanism 70 to move the second movable portion 71b in the -Z direction, thereby returning the active area from the third area U3 to the first area U1. The light receiving element 220 in the first area U1 is then used in the object detection process performed by the object detection unit 117.

[0081] When it is determined that no black line is detected in the above-mentioned step S15 (step S15: No), or after the execution of the above-mentioned step S36, or after the execution of the above-mentioned step S41, the fault detection process ends.

[0082] According to the object detection device 10 of the first embodiment having the above-described structure, an ambient light image Img1 is acquired using a first light reception signal corresponding to the light reception state of the light receiving elements within the first area U1 of the light receiving element array 22, in which a plurality of light receiving elements 220 are arranged in a planar manner. Failures in the light receiving elements 220 within the first area U1 are detected using the acquired ambient light image Img1. This allows for accurate detection of failures in the light receiving elements 220 while reducing the load on the object detection device 10. Specifically, according to the object detection device 10, since previously acquired ambient light images do not need to be stored in the memory 103 when detecting failures in the light receiving elements 220, the storage capacity used in the memory 103 can be reduced. Furthermore, since the image data of the ambient light image is not compared pixel by pixel with the image data of previously acquired ambient light images, the load on the CPU 110 can be reduced, and the presence or absence of a failure can be accurately detected.

[0083] When a failure is detected in the light-receiving element 220 in the first area U1, the second light-receiving signal corresponding to the light-receiving state of the light-receiving element 220 in the second area U2 is used to detect the object. Therefore, the light-receiving element 220 in which the failure is not detected can be used to detect the object. Therefore, the object can be detected with high accuracy.

[0084] Since, in the image data of the ambient light image Img1, when a group of pixels having a brightness value less than a predetermined value is arranged along the X direction, it is detected that the light receiving element 220 in the first area U1 may have failed, the possibility of failure of the light receiving element 220 in the first area U1 can be easily detected.

[0085] Since when it is detected that the light receiving element 220 in the first area U1 may have a fault, the third light receiving signal corresponding to the light receiving state of the light receiving element 220 in the third area U3 is used to obtain the ambient light image Img2 again. In the image data of the again obtained ambient light image Img2, when the pixel group with a brightness value below a preset value moves in the +Z direction relative to the original pixel position as the usage area moves from the first area U1 to the third area U3, it is detected that the light receiving element 220 in the first area U1 has a fault. Therefore, the fault of the light receiving element 220 in the first area U1 can be easily detected.

[0086] Since the first moving mechanism 50 includes first movable portions 51a and 51b that move the light receiving element array 22 in the X direction by driving the screw mechanism 60 via the motor 53, the light receiving element array 22 can be moved in the X direction with a simple structure. Since the second moving mechanism 70 includes second movable portions 71a and 71b that move the light receiving element array 22 in the Z direction by driving the screw mechanism 80 via the motor 73, the light receiving element array 22 can be moved in the Z direction with a simple structure. Alternatively, instead of mechanically moving the light receiving element array 22 to move the first area U1, a structure may also be provided in which the optical system including the light receiving lens 23 is mechanically driven to change the first area U1, i.e., the focal area, on the light receiving element array 22. This is because the focal area and focal position of 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.

[0087] B. Second embodiment:

[0088] Hereinafter, the same reference numerals are used for the same structures as those in the above-mentioned embodiment and the description thereof will be omitted. Figure 11 、 Figure 12 、 Figure 13 and Figure 14 As shown, the object detection device 10 a of the second embodiment differs from the object detection device 10 of the first embodiment in that it includes a first moving mechanism 50 a instead of the first moving mechanism 50 and a second moving mechanism 70 a instead of the second moving mechanism 70 .

[0089] The first moving mechanism 50 a differs from the first moving mechanism 50 of the first embodiment in that the motor 53 and the screw mechanism 60 are omitted and a lock mechanism 64 and an electromagnet 63 are provided.

[0090] The locking mechanism 64 restricts movement of the first movable parts 51a and 51b in the X direction. The locking mechanism 64 switches between a "locked state" and an "released state" in response to the start and stop of power to the electromagnet 63. The "locked state" prevents the first movable parts 51a and 51b from moving in the X direction, while the "released state" allows movement in the X direction. The locking 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 within 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.

[0091] The electromagnet 63 is positioned on the +Z-direction surface of the first movable portion 51b. When power is supplied to the electromagnet 63, a magnetic force is generated, and when power is stopped, the magnetic force disappears. Specifically, by controlling the power supplied to the electromagnet 63, the polarity of the electromagnet 63 and the disappearance of the magnetic field are adjusted. The excited electromagnet 63 applies its magnetic force to the spring member 66, controlling the insertion and removal of the lock pin 65 from the through-hole h1. In other words, the electromagnet 63 functions as a driver for the locking mechanism 64. The start and stop of power supply to the electromagnet 63 are controlled by the control unit 111.

[0092] The second moving mechanism 70 a differs from the second moving mechanism 70 of the first embodiment in that the motor 73 and the screw mechanism 80 are omitted and a locking mechanism 84 and an electromagnet 83 are provided.

[0093] The locking mechanism 84 restricts the Z-direction movement of the second movable portions 71a and 71b. The locking mechanism 84 switches between a "locked state" and an "released state" in response to the start and stop of power to the electromagnet 83. The "locked state" prevents the second movable portions 71a and 71b from moving in the Z-direction, while the "released state" allows them to move in the Z-direction. Similar to the locking mechanism 64 of the first moving mechanism 50a, the locking mechanism 84 includes a lock pin 85 and a spring member 86. The lock pin 85 is located on the -X direction side of the spring member 86 in the second movable portion 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 within the through-hole h2 in the second movable portion 71b. The spring member 86 is located on the -X direction side of the electromagnet 83 in the second movable portion 71b. The spring member 86 controls the movement of the lock pin 85 in the X direction by the magnetic force caused by the energization of the electromagnet 83 .

[0094] Electromagnet 83 is located on the +X-direction surface of second movable portion 71b. Similar to electromagnet 63 of first moving mechanism 50a, electromagnet 83 generates magnetic force when power is applied, and the magnetic force disappears when power is removed. When energized, electromagnet 83 exerts its magnetic force on spring member 86, controlling the insertion and removal of lock pin 85 from through-hole h2.

[0095] use Figure 15 and Figure 16 , a procedure for moving the light receiving element array 22 in the +Z direction in the second moving mechanism 70a will be described. Figure 15 Corresponding to Figure 14 , Figure 16 Corresponding to Figure 13 .exist Figure 15 In the locked state shown on the left side of , the power supply to the electromagnet 83 is stopped, and the front end (the end in the -Z direction) of the lock pin 85 is fixed in the through hole h2 by the force applied in the -Z direction by the spring component 86. Therefore, the movement of the second movable part 71b in the Z direction is restricted, and the light receiving element array 22 is fixed in the specified position in the normal mode. When the power supply to the electromagnet 83 is started, the electromagnet 83 is excited, and the lock pin 85 is pulled toward the electromagnet 83 side (+Z direction) by the magnetic force of the electromagnet 83. As a result, Figure 15 As shown on the right side of FIG, the front end of the lock pin 85 is pulled out from the through hole h2, and the locked state is released to become the released state.

[0096] like Figure 16 As shown on the left side of FIG, if the locked state is released, the force of the elastic member 77 in the -Z direction becomes weaker, and the elastic member 77 extends in the +Z direction. Figure 16As shown on the right side of FIG, the second movable portion 71b moves in the +Z direction, and as shown by the one-dot chain line, the center position of the light receiving element array 22 in the Z direction moves in the +Z direction.

[0097] use Figure 17 The operation of the lock pin 85 when the lock state is shifted from the locked state to the released state and the operation of the lock pin 85 when the lock state is shifted from the released state to the locked state again will be described. Figure 17 Corresponding to Figure 15 , the vicinity of the through hole h2 is magnified. Figure 17 In FIG, the axis CX shown by the single-dot chain line is the center axis of the through hole h2 in the Y direction, and the axis AX shown by the double-dot chain line is the center axis of the lock pin 85 in the Y direction. Figure 17 In the locked state shown in the leftmost figure, the lock pin 85 is fixed at a predetermined position in the through hole h2 in a state where its axis CX coincides with the axis AX of the through hole h2.

[0098] like Figure 17 The leftmost picture and Figure 17 As shown in the second figure from the left, when the locked state is transferred to the released state, the lock pin 85 rises to the side (+X direction) where the electromagnet 83 is arranged. As a result, the second movable part 71b can move in the +Z direction, and as the second movable part 71b moves, the position of the through hole h2 also moves. Therefore, the position of the axis AX of the lock pin 85 is arranged to be offset from the axis CX of the through hole h2 by an amount equivalent to the movement of the second movable part 71b. Then, as shown in FIG. Figure 17 As shown in the third and rightmost figure from the left, when the unlocked state is shifted to the locked state, the lock pin 85 descends toward the through hole h2, and the tip of the lock pin 85 is inserted into the through hole h2. At this time, since the second movable portion 71b has returned to its original position, the position of the axis CX of the lock pin 85 is returned to its original position and is aligned with the axis AX of the through hole h2.

[0099] like Figure 17 As shown in FIG, the front end of the lock pin 85 is tapered. Therefore, the lock pin 85 can be easily inserted into the through hole h2 and can be more firmly fixed to the through hole h2. Figure 17 In the example shown, the lock pin 85 is inserted into the through hole h2 along the axis AX of the through hole h2, but it can also be inserted in a direction intersecting the axis AX. By doing so, it is possible to suppress the lock pin 85 from coming out of the through hole h2 due to vehicle vibration or the like.

[0100] According to the object detection device 10a of the second embodiment having the above-described structure, the first moving mechanism 50a includes a locking mechanism 64 for restricting movement of the light receiving element array 22 in the X direction, an electromagnet 63 for controlling the switching between the locked and released states of the locking mechanism 64, and first movable portions 51a and 51b for moving the light receiving element array 22 in the X direction when the locking mechanism 64 is released. This allows the first moving mechanism to have a simpler structure. The second moving mechanism 70a includes a locking mechanism 84 for restricting movement of the light receiving element array 22 in the Z direction, an electromagnet 83 for controlling the switching between the locked and released states of the locking mechanism 84, and second movable portions 71a and 71b for moving the light receiving element array 22 in the Z direction when the locking mechanism 84 is released. This allows the second moving mechanism 70a to have a simpler structure.

[0101] C. 3rd embodiment:

[0102] like Figure 18 、 Figure 19 、 Figure 20 and Figure 21 As shown, the object detection device 10 b according to the third embodiment is different from the object detection device 10 according to the first embodiment in that a second movement mechanism 70 b is provided instead of the second movement mechanism 70 .

[0103] The second moving mechanism 70 b 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 77 a is provided instead of the elastic member 77 .

[0104] The piezoelectric body 87 is a component formed from a material exhibiting a piezoelectric effect, such as a piezoelectric element, and deforms in response to a voltage applied to electrodes (not shown). The application of voltage to the piezoelectric body 87 is controlled by the control unit 111, and voltage is applied when switching the aforementioned operating modes. The elastic member 77a is positioned between the -Z direction surface of the second movable portion 71a and the +Z direction surface of the second movable portion 71b.

[0105] use Figure 22 , a procedure for moving the light receiving element array 22 in the +Z direction in the second moving mechanism 70b will be described. Figure 22 Corresponding to Figure 20 .exist Figure 22 The left side shows the second moving mechanism 70b in the normal mode. Figure 22 The right side of the figure shows the second moving mechanism 70b in the fault detection mode. In the normal mode, no voltage is applied to the piezoelectric body 87. Figure 22As shown on the left side of FIG, the elastic member 77a pushes the piezoelectric body 87 against the surface of the second movable portion 71a in the +Z direction by the biasing force. As a result, the movement of the light receiving element array 22 in the Z direction is restricted.

[0106] If a voltage is applied to the piezoelectric body 87 when the normal mode is switched to the fault detection mode, Figure 22 As shown on the right side of the image, the piezoelectric element 87 elastically deforms. This deformation compresses the elastic member 77a in the +Z direction. Consequently, the second movable portion 71b is pushed upward in the +Z direction, and as shown by the dashed line, the center position of the light receiving element array 22 in the Z direction moves in the +Z direction. To return the light receiving element array 22 to its original position, simply stop applying voltage to the piezoelectric element 87.

[0107] According to the object detection device 10b of the third embodiment having the above-described structure, the second moving mechanism 70b includes a piezoelectric element 87 and second movable portions 71a and 71b that move the light receiving element array 22 in the Z direction when the piezoelectric element 87 is applied. This allows the second moving mechanism 70b to have a simpler structure. Furthermore, similar to the second moving mechanism 70b, the first moving mechanism 50 may also include a piezoelectric element as an actuator. In this case, the motor 53 and the screw mechanism 60 are omitted, and an elastic member 77a is provided in place of the elastic member 77.

[0108] D. 4th embodiment:

[0109] like Figure 23 、 Figure 24 、 Figure 25 and Figure 26 As shown in FIG. 1 , the object detection device 10 c according to the fourth embodiment differs from the object detection device 10 b according to the third embodiment in that a second moving mechanism 70 c is provided instead of the second moving mechanism 70 b .

[0110] The second moving mechanism 70c differs from the second moving mechanism 70b of the third embodiment in that the piezoelectric body 87 is omitted, the electromagnet 83 and the iron core 88 are provided, and an elastic member 77b is provided instead of the elastic member 77a.

[0111] The electromagnet 83 is positioned on the +Z surface of the second movable portion 71b. The electromagnet 83 has the same structure as the electromagnet of the second embodiment. When energized, it is magnetized, causing its magnetic force to reach the iron core 88, thereby controlling the Z-direction movement of the second movable portion 71b. When viewed from the X direction, the iron core 88 comprises a first iron core 88a extending in the Z direction and a second iron core 88b extending in the Y direction. One end of the first iron core 88a is inserted into the through-hole h3 formed between the second movable portion 71a and the second movable portion 71b, while the other end of the first iron core 88a abuts the -Z surface of the electromagnet 83. The second iron core 88b is positioned on the +Z surface of the second movable portion 71b, on the +Y side of the second movable portion 71b. The elastic member 77b is positioned on the outer circumferential surface of the through-hole h3.

[0112] use Figure 27 The procedure for moving the light receiving element array 22 in the +Z direction in the second moving mechanism 70 c will be described. Figure 27 Corresponding to Figure 25 .exist Figure 27 The left side shows the second moving mechanism 70c in the normal mode. Figure 27 The right side of the figure shows the second moving mechanism 70c in the fault detection mode. In the normal mode, the power supply to the electromagnet 83 is stopped. Figure 27 As shown on the left side of FIG, the first core 88a and the second core 88b are arranged at positions separated from each other, and the elastic member 77b is maintained in a state of being extended in the Z direction. As a result, the movement of the light receiving element array 22 in the +Z direction is restricted.

[0113] If the electromagnet 83 is energized when the normal mode is switched to the fault detection mode, Figure 27 As shown on the right side of the image, the magnetic force of the electromagnet 83 is transmitted to the iron core 88, causing the second iron core 88b to approach the first iron core 88a, and the elastic member 77b to deform (compress in the Z direction). With this deformation, the first iron core 88a and the second iron core 88b come into contact, and the second movable portion 71b is pushed upward in the +Z direction. As shown by the dotted line, the center position of the light receiving element array 22 in the Z direction moves in the +Z direction. To return the light receiving element array 22 to its original position, it is sufficient to simply stop supplying power to the electromagnet 83.

[0114] According to the object detection device 10c of the fourth embodiment having the above-described structure, the second moving mechanism 70c includes the electromagnet 83 and the second movable portions 71a and 71b that move the light receiving element array 22 in the Z direction by adjusting the polarity of the electromagnet 83 or eliminating the magnetic field. This allows the second moving mechanism 70b to have a simpler structure. Furthermore, similar to the second moving mechanism 70c, the first moving mechanism 50 may also include an electromagnet and an iron core as actuators. In this case, the motor 53 and the screw mechanism 60 are omitted, and an elastic member 77b is provided in place of the elastic member 77.

[0115] E. 5th embodiment:

[0116] In the first embodiment, the light receiving element array 22 is mechanically moved in the horizontal direction HD and the vertical direction VD by the first moving mechanism 50 and the second moving mechanism 70, thereby changing the first area U1 on the light receiving element array 22, executing a fault detection process for the light receiving elements 220, and receiving the results of the fault detection process to achieve a change / movement of the use area. In contrast, in the fifth embodiment, the first area U1 on the light receiving element array 22 is electronically moved by switching the light receiving elements 220 corresponding to the first area U1, thereby achieving a fault detection process for the light receiving elements 220 and a change / movement of the use area. The structure 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 the function of executing the switching of the first area U1 through electronic control. Therefore, the same reference numerals as those of the first embodiment are used and their description is omitted.

[0117] In the first embodiment, in order to simplify the description, an example is given 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. Generally, a light-receiving pixel is used as a term to represent the smallest unit of light-receiving processing, that is, the light-receiving unit corresponding to the detection point of the object detection device, and can be composed of a single light-receiving element 220 or a plurality of light-receiving elements 220. Figure 28 In the example of FIG, as shown in the enlarged view indicated by the arrow, four light-receiving elements 220 constitute one light-receiving pixel 221, and it can be said that the light-receiving element array 22 is composed of a plurality of light-receiving pixels 221. Figure 28 In the example, the light receiving element NGE is the light receiving element 220 that has failed.

[0118] The light receiving unit 20 of the fifth embodiment, more specifically the light receiving control unit 21, in addition to executing light receiving processing in units of light receiving pixels 221, can also execute light receiving processing in units of light receiving elements 220 constituting the light receiving pixels 221 and output the first light receiving signal. That is, the light receiving unit 20 can switch the execution of the light receiving processing on / off (light receiving / not light receiving) in units of each light receiving element 220 constituting each light receiving pixel 221 for each light receiving pixel 221 constituting the first area U1. Figure 28 In the example, the light receiving unit 20 can sequentially switch the execution of the light receiving process on and off for the four light receiving elements 220 constituting the light receiving pixel 221, for example, from the upper left side to the upper right side and from the lower left side to the lower right side. As a result, if there is no change in the first light receiving signal between when the light receiving process is turned on and off for a light receiving element 220, it can be determined that the light receiving element 220 is malfunctioning, that is, has failed. The absence of a change in the first light receiving signal means that there is no change in the signal intensity or signal value that is greater than a predetermined difference between when the light receiving process is turned on and off. In addition, each light receiving element 220 can be specified in the light receiving control unit 21 by specifying an address associated with a light receiving element number pre-assigned to each light receiving element 220 or pre-assigned coordinate position information. The execution of the light receiving process is turned on and off by connecting or disconnecting the electrical connection between the target light receiving element 220 and a measurement circuit, such as an adder.

[0119] Executed by the fault detection unit 113 Figure 29The fault detection process of the light receiving element unit shown. In addition, the fault detection process can use ambient light and be executed at each preset time interval when the object detection device 10 is started. Alternatively, it can also be executed in order to identify the light receiving element 220 that has a fault or a bad condition when a fault is detected by the mechanical fault detection process of the first embodiment. The fault detection unit 113 sets all the light receiving elements 220 constituting the first area U1 to be turned on for the light receiving process execution via the light receiving control unit 21, and executes the first light receiving process using ambient light (step S100). The fault detection unit 113 sets the light receiving elements 220 constituting the first area U1 to be disconnected as light receiving element units via the light receiving control unit 21 in accordance with a preset order, that is, sets the light receiving process execution of one light receiving element 220 to be disconnected (step S102). The fault detection unit 113 performs a second light reception process of the ambient light using the first area U1 (step S104), and determines whether a change has occurred between the amount of light received during the first light reception process and the amount of light received during the second light reception process (step S106). More specifically, the fault detection unit 113 determines whether a difference greater than a preset difference exists between the signal value of the first light reception signal output during the first light reception process and the signal value of the first light reception signal obtained during the second light reception process.

[0120] If the fault detection unit 113 determines that the amount of received light has changed (step S106: Yes), it determines that the light receiving element 220 set to OFF for light reception processing is normal (step S108), and the process proceeds to step S112. If the fault detection unit 113 determines that the amount of received light has not changed (step S106: No), it determines that the light receiving element 220 set to OFF for light reception processing has failed (step S110), stores the light receiving element number and coordinate position information used for identification in the memory 103, and the process proceeds to step S112. This is because the fact that the amount of received light of the target light receiving element 220 does not change due to the on / off switching of the light reception processing means that the target light receiving element 220 is unable to receive ambient light when the light reception processing is on. The fault detection unit 113 determines whether the light reception processing execution is turned off for all the light receiving elements 220 constituting the first area U1 (step S112). If the light reception processing execution is not turned off for all the light receiving elements 220 (step S112: No), the process moves to step S100. In step S102, the light reception processing execution is set to off for the next light receiving element 220, and steps S104 to S112 are executed. If the light reception processing execution is turned off for all the light receiving elements 220 (step S112: Yes), the fault detection unit 113 ends this processing routine.

[0121] The object detection device 10 according to the fifth embodiment does not include a structure for mechanically driving the light-receiving element array 22, but can electronically detect a failure or malfunction in the first area U1. Furthermore, the object detection device 10 according to the fifth embodiment can detect a failure or malfunction in the first area U1 on a per-light-receiving element 220 basis. As a result, the need to move or change the area used to avoid a failure or malfunction in the first area U1 during object detection can be minimized.

[0122] In the above example, light reception processing is performed across the entire first area U1, with each light receiving element 220 performing a shutoff to detect a failure in the light receiving element 220. This processing sequence allows for highly accurate detection of a failure or malfunction in the light receiving element 220. Alternatively, the first area U1 can be divided into any predetermined number of areas, with the aforementioned failure detection process performed at different timings for each divided area. Alternatively, the first area U1 can be divided into two, with all light receiving elements 220 in each area performing the light reception processing. The same processing is then performed for areas with less light reception, and the aforementioned failure detection process is performed for each light receiving element 220 when a predetermined number of light receiving pixels 221 has been reached. In these cases, the time required for the detection process can be shortened. Furthermore, the first area U1 can be divided into two, with the aforementioned failure detection process performed for each area, with the division and failure detection process repeated for areas with larger cumulative differences in light reception intensity. By comparing signal values ​​using a binary search method, search efficiency is improved, and detection processing time can be shortened.

[0123] F. 6th embodiment:

[0124] In the sixth embodiment, when a failure or malfunction is detected in the light receiving element 220 constituting the first area U1 by the failure detection process of the first and fifth embodiments, Figure 30 As shown, the object detection process is performed using the mobile usage area U11 that electronically moves the first area U1. This differs from the first to fourth embodiments, in which the first area U1 is mechanically moved. The basic structure of the object detection device according to the sixth embodiment is the same as that described in the fifth embodiment, and therefore, the same reference numerals are used and description thereof will be omitted.

[0125] The fault detection unit 113 receives the result of the fault detection process that the light receiving element NGE constituting the first area U1 has failed, and causes the control unit 111 to shift to the fault countermeasure mode. The control unit 111 sets the light receiving element 220 corresponding to the mobile use area U11 as the light receiving pixel 221 used in the first area U1, that is, the light receiving element 220. As already mentioned, addresses for determining positions are pre-assigned to the light receiving elements 220 constituting the light receiving element array 22. Therefore, as the light receiving element 220 used in the object detection process, by setting the address of the light receiving element 220 corresponding to the mobile use area U11 instead of the address of the light receiving element 220 corresponding to the first area U1, it is possible to implement object detection processing using the mobile use area U11, that is, to implement light receiving processing for receiving reflected light corresponding to the irradiated light emitted from the light emitting unit 30. In Figure 30 In the example shown in FIG, to avoid the faulty light-receiving element NGE, the used area is slid while maintaining the overlapping area in the horizontal direction (crosswise) of the drawing. Depending on the location of the faulty light-receiving element NGE, there may be no overlapping area. Furthermore, if the first area U1 does not span the entire vertical direction (longitudinal direction), a movable used area in the vertical, horizontal, or vertically offset direction may be set.

[0126] According to the object detection device 10 according to the sixth embodiment, the first area U1 can be changed without using a drive unit for mechanically driving the light-receiving element array 22. Furthermore, since the use area U11 is moved by horizontally moving the first area U1, the use area can be changed while maintaining continuity between the light-receiving elements 220 with respect to light-receiving characteristics such as SN. Furthermore, object detection processing can be performed by performing the same light-receiving control as for the first area U1. Furthermore, when performing fault detection processing by dividing the first area U1 into multiple areas, only the area containing the faulty light-receiving element NGE can be moved. In this case, the decrease in SN associated with the movement of the first area U1 can be suppressed.

[0127] G. 7th Implementation Method:

[0128] In the seventh embodiment, when a failure or malfunction is detected in the light receiving element 220 constituting the first area U1 by the failure detection process of the fifth embodiment, as shown in FIG. Figure 31 As shown in FIG. 1 , the object detection process is performed in the mobile use area U12 after a part of the use area is electronically moved. This point is different from the sixth embodiment. In addition, the basic structure of the object detection device of the seventh embodiment is the same as that described in the fifth embodiment, so the same reference numerals are given and the description thereof is omitted. Figure 31In FIG, the first area U1 overlaps with the mobile use area U21, and thus description thereof is omitted.

[0129] Upon receiving the result of the fault detection process indicating that the light receiving element NGE constituting the first area U1 has failed, the fault detection unit 113 causes the control unit 111 to shift to a fault countermeasure mode. The control unit 111 then sets the light receiving element 220 corresponding to the mobile use area U12 as the light receiving pixel 221, i.e., the light receiving element 220, used in the first area U1. In the seventh embodiment, of the light receiving elements 220 constituting the first area U1, only the failed light receiving element NGE is excluded from the first area U1, and the mobile use area U12, which is a portion of the first area moved, is used to include the replacement light receiving element 121. Specifically, the address of the light receiving element 220 corresponding to the mobile use area U12, to which the address of the replacement light receiving element 121 is added, is set as the light receiving element 220 used in the object detection process, replacing the address of the failed light receiving element NGE in the first area U1. This enables object detection processing using the mobile use area U12. The movement of the first area U1 in the seventh embodiment is realized by combining with the failure detection process capable of identifying the light receiving element 220 in which a failure has occurred, that is, the failure detection process described in the fifth embodiment.

[0130] According to the object detection device 10 according to the seventh embodiment, the first area U1 can be changed without using a drive unit for mechanically driving the light-receiving element array 22. Furthermore, the use area U12 is moved by simply excluding the failed light-receiving element NGE from the light-receiving elements 220 that constitute the use area UI. This allows the same SN as when the first area U1 is used. Specifically, the first area U1, which is set to the initial position, is the area with the best SN in the light-receiving element array 22. Therefore, by maintaining the light-receiving elements 220 other than the failed light-receiving element NGE, the desired light-receiving characteristics can be achieved. Furthermore, the partial area is not limited to the case where there is only one failed light-receiving element NGE; it can also be applied to the case where there are multiple failed light-receiving elements NGE.

[0131] H. 8th embodiment:

[0132] In the eighth embodiment, when a failure or malfunction is detected in the light receiving element 220 constituting the first area U1 by the failure detection process of the first and fifth embodiments, Figure 32As shown, the object detection process is performed using the expanded use area U13 that electronically expands the first area U1, which is different from the sixth and seventh embodiments. The basic structure of the object detection device according to the eighth embodiment is the same as that described in the fifth embodiment, so the same reference numerals are used and the description thereof will be omitted.

[0133] Upon receiving the result of the fault detection process indicating that the light-receiving element NGE constituting the first area U1 has failed, the fault detection unit 113 causes the control unit 111 to shift to the fault countermeasure mode. The control unit 111 then sets the light-receiving element 220 corresponding to the extended use area U13 as the light-receiving pixel 221, i.e., the light-receiving element 220 used in the first area U1. In the eighth embodiment, the extended use area U13, which includes the first area U1 and the light-receiving element NGE determined to have failed and is horizontally expanded, is used. Specifically, in addition to the addresses of the light-receiving elements 220 constituting the first area U1, the addresses of the light-receiving elements 220 corresponding to the extended use area U13 are set as the light-receiving elements 220 used in the object detection process, thereby implementing object detection processing using the extended use area U13.

[0134] According to the object detection device 10 according to the eighth embodiment, the first area U1 can be modified without using a drive unit for mechanically driving the light-receiving element array 22. Furthermore, since the expanded usable area U13 is achieved by expanding the first area U1, the decrease in signal strength associated with the loss of the faulty light-receiving element 220 can be compensated. Furthermore, when performing fault detection processing by dividing the first area U1 into multiple areas, only the area containing the faulty light-receiving element NGE can be expanded. In this case, the generation of noise associated with the expansion of the first area U1 can be suppressed.

[0135] I. Other implementation methods:

[0136] (1) In the above embodiments, the third area U3 is located in the +Z direction relative to the first area U1. However, it may also be located in the -Z direction relative to the first area U1. In this case, in the second moving mechanisms 70, 70a, 70b, and 70c, by moving the second movable portion 71b relative to the second movable portion 71a in the -Z direction, the use area can be moved from the first area U1 to the third area U3. Furthermore, when transitioning from the fault detection mode to the fault countermeasure mode, the use area is returned from the third area U3 to the first area U1 and then moved to the second area U2. However, this return to the first area U1 may be omitted. In other words, the second area U2 may be a region in which the third area U3 is moved parallel to the X direction.

[0137] (2) In the first embodiment described above, in order to eliminate the gap between the screw mechanisms (positional errors caused by the gap between the components that transmit the driving force), an elastic member may be used to press the first moving mechanism 50 and the second moving mechanism 70 against each other. Furthermore, 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 and Z directions.

[0138] (3) In each of the above embodiments, when it is determined that the light receiving element 220 in the first area U1 is likely to have failed or is in the process of failing, another sensor different from the distance measuring device 200, such as an imaging device or a laser radar different from the distance measuring device 200, may be used to detect the object. Furthermore, a user of the object detection device 10, such as an occupant of a vehicle equipped with the object detection device 10 or a vehicle manager, may be notified of the failure.

[0139] (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. However, the first moving mechanism 50a of the second embodiment may be used instead. Furthermore, the first moving mechanisms 50, 50a and the second moving mechanisms 70, 70b, 70c, and 70d of each embodiment may be used in any combination.

[0140] (5) In each of the above embodiments, the possibility of a 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 black lines in the ambient light image, that is, the presence or absence of pixel columns with brightness values ​​less than a first predetermined value. However, instead of or in addition to the presence or absence of black lines, detection may be performed based on the presence or absence of white lines, that is, the presence or absence of pixel columns forming bright lines with brightness values ​​greater than a second predetermined value different from the first predetermined value. In this case, it is sufficient to detect whether a group of pixels with a brightness value of 255 is arranged along the X direction in the image data of the ambient light image. In addition, the brightness value is not limited to 255, and a value greater than the brightness value that is a reference value for high brightness may be used. Furthermore, when the brightness difference between the brightness value of the pixel column forming the black or white line and the brightness value of the pixel column adjacent to the pixel column forming the black or white line is greater than a predetermined difference, it may be determined that a black or white line exists, that is, a failure of the light receiving element 220 is determined. For example, in very bright conditions, the ambient light image as a whole becomes brighter, and in nighttime, the ambient light image as a whole becomes darker. Therefore, if the determination condition is simply that the luminance value of a pixel row is below a first predetermined value or above a second predetermined value, a failure of the light-receiving element 220 may be determined even when the ambient light image is bright or dark as a whole. Therefore, by using the difference in luminance value between the target pixel row and the adjacent pixel row, which is below the first predetermined value or above the second predetermined value, as a further determination condition, the accuracy of black or white line discrimination can be improved.

[0141] (6) In each of the above embodiments, the control unit 111 determines that a failure is possible when a black line is detected, and changes the use area from the first area U1 to the third area U3. The failure detection unit 113 determines whether the position of the detected black line has moved, thereby determining that the light receiving element 220 has failed. Alternatively, the failure detection unit 113 may determine that the light receiving element 220 has failed when a pixel column having a luminance value of less than a first predetermined value or a pixel column having a luminance value greater than a second predetermined value is continuously detected at the same position in a plurality of acquired ambient light images.

[0142] (7) The various parts and methods of the control unit, etc. described in the present disclosure may also be implemented by a dedicated computer provided by a processor and memory that are programmed to execute one or more functions embodied by a computer program. Alternatively, the various parts and methods of the control unit, etc. described in the present disclosure may also be implemented by a dedicated computer provided by a processor composed of one or more dedicated hardware logic circuits. Alternatively, the control unit and methods described in the present disclosure may also be implemented by one or more dedicated computers composed of a combination of a processor and memory that are programmed to execute one to multiple functions and a processor composed of one or more hardware logic circuits. In addition, the computer program may also be stored as instructions executed by the computer in a non-transitory tangible recording medium that is readable by the computer.

[0143] The present disclosure is not limited to the above-mentioned embodiments and can be implemented by various structures within the scope of its main purpose. For example, the technical features in the embodiments corresponding to the technical features in each form described in the invention content column can be appropriately replaced or combined in order to solve part or all of the above-mentioned problems or to achieve part or all of the above-mentioned effects. In addition, as long as the technical features are not described as necessary in this specification, they can be appropriately deleted.

Claims

1. An object detection device, detecting an object, have: a light receiving unit having a light receiving surface formed by a planar arrangement of a plurality of light receiving elements capable of receiving incident light, wherein a predefined usable area of ​​the usable area of ​​the light receiving surface is defined as a first area, and a third area that is different from or partially overlaps with the first area, and outputting 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, wherein the incident light includes reflected light of the emitted irradiation light; an image acquisition unit that acquires a first ambient light image indicating the intensity of ambient light received using the first light reception signal, and acquires a third ambient light image indicating the intensity of ambient light received using the third light reception signal; and The fault detection unit detects a fault of the light-receiving element in the first area using the first ambient light image and the third ambient light image. When the position of a pixel group whose brightness value in the first ambient light image is less than a first preset value or greater than a second preset value different from the first preset value moves in the third ambient light image, the fault detection unit detects a fault of the light-receiving element in the first area.

2. The object detection device according to claim 1, The light receiving unit can output 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 area using the first light receiving signal outputted in units of the divided areas.

3. The object detection device according to claim 1, The light receiving unit can output the first light receiving signal using the light receiving elements in the first area as a unit. The failure detection unit detects a failure of the light receiving element in the first area using the first light receiving signal outputted by each light receiving element.

4. The object detection device according to any one of claims 1 to 3, Also features: an object detecting unit for detecting the object using the light receiving signal outputted by the light receiving unit; a first moving mechanism for moving the use area to a second area located in a first direction relative to the first area; and a control unit for controlling the driving of the first moving mechanism; The light receiving unit outputs a second light receiving signal corresponding to the light receiving state of the light receiving element in the second area. The object detection unit detects the object using the second light reception signal when a failure of the light receiving element in the first area is detected.

5. The object detection device according to any one of claims 1 to 3, In the image data of the first ambient light image, when the pixel group is arranged along the first direction, the failure detection unit detects that there is a possibility that the light receiving element in the first area has failed.

6. The object detection device according to claim 5, Also features: a second moving mechanism for moving the use area to the third area located in a second direction perpendicular to the first direction relative to the first area; and a control unit for controlling the driving of the second moving mechanism; When it is detected that the light receiving element in the first area may fail, the image acquisition unit acquires the third ambient light image using the third light receiving signal. In the image data of the third ambient light image obtained, when the pixel group moves toward the second direction relative to the original pixel position as the usage area moves from the first area to the third area, the fault detection unit detects that the light receiving element in the first area has a fault.

7. The object detection device according to claim 4, The first moving mechanism includes: Threaded mechanism; a motor driving the threaded mechanism; and The first movable portion is driven by the screw mechanism to move the light receiving surface along the first direction.

8. The object detection device according to claim 4, The first moving mechanism includes: A locking mechanism for limiting movement of the light receiving surface in the first direction; a driving unit for controlling the switching between the locked state and the released state of the locking mechanism; and The first movable portion moves the light receiving surface in the first direction when the locking mechanism is in the released state.

9. The object detection device according to claim 4, The first moving mechanism includes: piezoelectric body; and The first movable portion moves the light receiving surface along the first direction when the piezoelectric body is applied thereto.

10. The object detection device according to claim 4, The first moving mechanism includes: electromagnets; and The first movable portion moves the light receiving surface along the first direction by adjusting the change of the polarity of the electromagnet or the disappearance of the magnetic field.

11. The object detection device according to claim 6, The second moving mechanism has: Threaded mechanism; a motor driving the threaded mechanism; and The second movable portion is driven by the screw mechanism to move the light receiving surface along the second direction.

12. The object detection device according to claim 6, The second moving mechanism has: A locking mechanism for limiting movement of the light-receiving surface in the second direction; a driving unit for controlling the switching between the locked state and the released state of the locking mechanism; and The second movable portion moves the light receiving surface in the second direction when the locking mechanism is brought into the released state.

13. The object detection device according to claim 6, The second moving mechanism has: piezoelectric body; and The second movable portion moves the light receiving surface along the second direction when the piezoelectric body is applied thereto.

14. The object detection device according to claim 6, The second moving mechanism has: electromagnets; and The second movable portion moves the light receiving surface along the second direction by adjusting the change of the polarity of the electromagnet or the disappearance of the magnetic field.

15. The object detection device according to any one of claims 1 to 3, It also includes an object detection unit that detects the object using the light reception 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 orthogonal to the first direction to receive the incident light. When a fault of the light-receiving element in the first area is detected, the light-receiving control unit moves the use area to the second area located in the first direction relative to the first area to receive the incident light, and the light-receiving unit outputs a second light-receiving signal corresponding to the light-receiving state of the light-receiving element in the second area. The object detection unit detects the object using the second light-receiving signal.

16. The object detection device according to any one of claims 1 to 3, It also includes an object detection unit that detects the object using the light reception 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 orthogonal to the first direction to receive the incident light. When a fault of the light-receiving element in the first area is detected, the light-receiving control unit receives the incident light in a second area obtained by expanding the use area in the first direction relative to the first area, and the light-receiving unit outputs a second light-receiving signal corresponding to the light-receiving state of the light-receiving element in the second area. The object detection unit detects the object using the second light-receiving signal.

17. The object detection device according to claim 3, It also includes an object detection unit that detects the object using the light reception signal output by the light receiving unit. The light receiving unit includes a light receiving control unit that moves a portion of the use area corresponding to the light receiving element in at least one of a first direction and a second direction orthogonal to the first direction to receive the incident light. When a fault of the light-receiving element in the first area is detected, the light-receiving control unit moves the part of the use area to the second area located in the first direction relative to the first area to receive the incident light, and the light-receiving unit outputs a second light-receiving signal corresponding to the light-receiving state of the light-receiving element in the second area. The object detection unit detects the object using the second light-receiving signal.

18. A method of detecting a fault in an object detection device, A method for generating a light receiving surface comprising a plurality of light receiving elements arranged in a planar shape and configured to receive incident light, wherein one of the plurality of used areas is defined as a first area, and a third area is defined as a third area that is different from or partially overlaps with the first area. The method outputs a first light receiving signal corresponding to the light receiving state of the light receiving elements in the first area and a third light receiving signal corresponding to the light receiving state of the light receiving elements in the third area, wherein the incident light includes reflected light of the emitted irradiated light. Using the first light receiving signal, a first ambient light image representing the received light intensity of the ambient light is obtained; using the third light receiving signal, a third ambient light image representing the received light intensity of the ambient light is obtained; Using the first ambient light image and the third ambient light image, when the position of a pixel group whose brightness value in the first ambient light image is less than a first preset value or greater than a second preset value different from the first preset value moves in the third ambient light image, a fault of the light receiving element in the first area is detected.

Images