Target recognition device

Abstract

To effectively improve recognition accuracy of a target.SOLUTION: A target recognition device includes: a camera 42 configured to capture a front of a vehicle VH in a prescribed range; and a target recognition part 110 configured to apply prescribed image processing to a captured image captured by the camera 42 so as to recognize an existence of a target in the captured image. The target recognition device further includes: a region identification part 120 configured to respectively identify a light control region A in which irradiation light is shielded or dimmed by a light distribution control part 100 configured to control an irradiation range of the irradiation light emitted from a head lamp 60 equipped in the vehicle VH, and an irradiation region B in which the irradiation light is not shielded or dimmed. The target recognition part 110 executes first image processing in the irradiation region B identified by the region identification part 120 and second image processing that enhances a luminance of the captured image, in comparison to the first image processing, in the light control region A identified by the region identification part 120.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to an object recognition device, and particularly to a technique suitable for recognizing an object in front of a vehicle.

Background Art

[0002] For example, Patent Document 1 discloses a technique for enabling appropriate object recognition even in a low beam state by changing a correction threshold value of a pixel value used for image recognition processing between a case where a vehicle-mounted headlight is in a low beam state and a case where the headlight is in a high beam state.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] For example, in a vehicle equipped with a system that partially switches between a high beam state and a low beam state, such as an Adaptive High-beam System (AHS), the irradiation area of the headlight is always variable in each of the high beam state and the low beam state. Therefore, simply changing the correction threshold value of the pixel value based on whether the headlight is in the low beam state or the high beam state, as in the device described in Patent Document 1, does not appropriately perform the correction process, and there is a possibility of false detection or non-detection of an object.

[0005] The technique of the present disclosure has been made in view of the above circumstances, and an object thereof is to effectively improve the recognition accuracy of an object.

[0006] The object recognition device of the present disclosure is imaging means for imaging a predetermined range in front of the vehicle, A target recognition device comprising: a target recognition means for recognizing the presence of a target in the captured image by performing predetermined image processing on the captured image captured by the imaging means. Region specifying means for specifying a dimming region, which is a region where the irradiation light is shielded or dimmed, and an irradiation region where the irradiation light is not shielded or dimmed, by means of a light distribution control means for controlling the irradiation range of the irradiation light emitted from the headlamp provided in the vehicle. In the irradiation region specified by the region specifying means, the target recognition means performs first image processing, and in the dimming region specified by the region specifying means, second image processing for increasing the luminance of the captured image is performed as compared with the first image processing. Characterized by the above.

Brief Description of Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0008] Hereinafter, the target recognition device according to the present embodiment will be described with reference to the drawings.

[0009] [Hardware Configuration] FIG. 1 is a schematic diagram showing the hardware configuration of a vehicle VH according to the present embodiment. Hereinafter, when it is necessary to distinguish the vehicle VH from other vehicles or the like, it may be referred to as the host vehicle.

[0010] The vehicle VH has an ECU (Electronic Control Unit) 10. The ECU 10 includes a CPU (Central Processing Unit) 11, a ROM (Read Only Memory) 12, a RAM (Random Access Memory) 13, an interface device 14, etc. The CPU 11 is a processor that executes various programs stored in the ROM 12. The ROM 12 is a non-volatile memory that stores data and the like necessary for the CPU 11 to execute various programs. The RAM 13 is a volatile memory that provides a work area where various programs are expanded when executed by the CPU 11. The interface device 14 is a communication device for communicating with external devices.

[0011] The ECU 10 is a central device that performs driving assistance control such as collision avoidance control (Pre-Crash Safety Control: hereinafter, PCS control). The driving assistance control is a concept that includes automatic driving control. The following devices are communicably connected to the ECU 10: a drive device 20, a steering device 21, a braking device 22, an in-vehicle sensor device 30, an external sensor device 40, a cornering light sensor 50, a left headlight 60L, a right headlight 60R, an HMI (Human Machine Interface) 70, etc.

[0012] The drive device 20 generates a driving force transmitted to the drive wheels of the vehicle VH. Examples of the drive device 20 include an electric motor and an engine. In the present implementation device, the vehicle VH may be any of a hybrid vehicle (HEV), a plug-in hybrid vehicle (PHEV), a fuel cell vehicle (FCEV), a battery electric vehicle (BEV), and an engine vehicle. The steering device 21 applies a steering force to the wheels of the vehicle VH. The braking device 22 applies a braking force to the wheels of the vehicle VH.

[0013] The in-vehicle sensor device 30 is a group of sensors that acquires the state of the vehicle VH. The in-vehicle sensor device 30 includes a vehicle speed sensor 31, an accelerator sensor 32, a brake sensor 33, a steering angle sensor 34, a steering torque sensor 35, a yaw rate sensor 36, and the like.

[0014] The vehicle speed sensor 31 detects the traveling speed (vehicle speed V) of the vehicle VH. The accelerator sensor 32 detects the operation amount of an accelerator pedal (not shown) by the driver. The brake sensor 33 detects the operation amount of a brake pedal (not shown) by the driver. The steering angle sensor 34 detects the rotation angle (steering angle) of a steering wheel or a steering shaft (not shown). The steering torque sensor 35 detects the rotational torque (steering torque) of a steering wheel or a steering shaft (not shown). The yaw rate sensor 36 detects the yaw rate of the vehicle VH. The in-vehicle sensor device 30 transmits the state of the vehicle VH detected by each of the sensors 31 to 36 to the ECU 10 at a predetermined cycle.

[0015] The external sensor device 40 is a group of sensors that recognizes target information regarding targets around the vehicle VH. Specifically, the external sensor device 40 includes a radar sensor 41, a camera 42, and the like. Here, examples of the target information include surrounding vehicles, pedestrians, traffic signals, white lines on the road, signs, and the like.

[0016] The radar sensor 41 detects targets existing around the vehicle VH. The radar sensor 41 includes a millimeter-wave radar and / or a lidar. The millimeter-wave radar emits radio waves (millimeter waves) in the millimeter-wave band, and receives the millimeter waves (reflected waves) reflected by the targets existing within the radiation range. The millimeter-wave radar obtains the relative distance between the vehicle VH and the target, the relative speed between the vehicle VH and the target, etc. based on the phase difference between the transmitted millimeter waves and the received reflected waves, the attenuation level of the reflected waves, and the time from transmitting the millimeter waves to receiving the reflected waves. The lidar sequentially scans pulsed laser light with a shorter wavelength than millimeter waves in a plurality of directions, and receives the reflected light reflected by the target, thereby obtaining the shape of the target detected in front of the vehicle VH, the relative distance between the vehicle VH and the target, the relative speed between the vehicle VH and the target, etc. The camera 42 is the imaging means of the present disclosure, and obtains target information in front of the vehicle VH by imaging the front of the vehicle VH. As the camera 42, for example, a digital camera having an image sensor such as a CMOS or a CCD can be used. The external sensor device 40 repeatedly transmits the target information obtained by the radar sensor 41 and the camera 42 to the ECU 10 every time a predetermined time elapses.

[0017] The conlite sensor (illuminance sensor) 50 is a sensor that detects the illuminance of light. The conlite sensor 50 is mounted on the vehicle VH so as to be able to detect the illuminance around the vehicle VH. The conlite sensor 50 transmits the detected illuminance information to the ECU 10 at a predetermined cycle.

[0018] The left front headlight 60L and the right front headlight 60R irradiate irradiation light toward the front of the vehicle VH. Here, the front of the vehicle VH is a concept that includes not only the front direction but also the left obliquely front and the right obliquely front. The left front headlight 60L is provided on the left side of the front part of the vehicle VH. The right front headlight 60R is provided on the right side of the front part of the vehicle VH. Note that the left front headlight 60L and the right front headlight 60R are basically configured substantially the same and are mirror images of each other. For this reason, hereinafter, when there is no need to distinguish between the left front headlight 60L and the right front headlight 60R, they are simply also referred to as "headlight 60".

[0019] The headlamp 60 includes a low-beam headlamp and a high-beam headlamp. The low-beam headlamp irradiates low-beam irradiation light to the front area of the vehicle VH. The high-beam headlamp irradiates high-beam irradiation light to a wider area than the low-beam irradiation light toward the front of the vehicle VH. The headlamp 60 is turned on or off according to an instruction signal transmitted from the ECU 10 in response to an operation of an operation device (not shown) by the driver. Also, when the operation device (not shown) is operated to the automatic position, the headlamp 60 is turned on or off according to an instruction signal transmitted from the ECU 10 based on the illuminance information acquired by the ambient light sensor 50.

[0020] The headlamp 60 is an AHS-compatible headlamp, and has a function of shielding a part of the irradiation area by high-beam irradiation according to the position of a dimming target object (for example, a preceding vehicle, an oncoming vehicle, a pedestrian, a sign, etc.) acquired by the external sensor device 40. In the present disclosure, shielding is a concept including light reduction. Examples of the headlamp having such a function include those provided with a plurality of LEDs (Light Emitting Diodes) arranged in a matrix, or those provided with a DMD (Digital Mirror Device) constituted by a plurality of micro mirror elements arranged in a matrix, or those provided with a MEMS (Micro Electro Mechanical Systems) mirror. Since the configurations of these headlamps are well-known, detailed descriptions thereof are omitted.

[0021] The HMI 70 is an interface for inputting and outputting information between the ECU 10 and the driver, and includes an input device and an output device. Examples of the input device include a touch panel, a switch, a voice pickup microphone, etc. Examples of the output device include a display device 71, a speaker 72, etc. The display device 71 is, for example, a center display, a multi-information display, a head-up display, etc. The speaker 72 is, for example, a speaker of an audio system or a navigation system.

[0022] [Software Configuration] Figure 2 is a schematic diagram showing the software configuration of the ECU 10 according to the present embodiment. As shown in Figure 2, the ECU 10 includes a light distribution control unit 100, an object recognition unit 110, an irradiation dimming area specifying unit 120, a PCS control unit 130, etc. as functional elements. Each of these functional elements 100 to 130 is realized by the CPU 11 of the ECU 10 reading out the program stored in the ROM 12 and executing it in the RAM 13. Note that all or part of each of the functional elements 100 to 130 can also be provided in another ECU separate from the ECU 10, or an information processing device of a facility (such as a management center) capable of communicating with the vehicle VH.

[0023] The light distribution control unit 100 is the light distribution control means of the present disclosure. It acquires the position of the dimming target object in front of the vehicle VH based on the detection result of the external sensor device 40, and performs light distribution control to shield or dim a part of the irradiation area by high beam irradiation according to the position of the acquired dimming target object. Examples of the dimming target object include a preceding vehicle, an oncoming vehicle, the face of a pedestrian, a road sign, etc. Shielding or dimming the position of the preceding vehicle or oncoming vehicle, or the position of the face of a pedestrian can prevent the driver of the preceding vehicle, oncoming vehicle, or pedestrian from being dazzled by glare. Also, shielding or dimming the position of a retroreflective object such as a road sign can prevent the driver of the own vehicle VH from being dazzled by the reflected light from the retroreflective object.

[0024] Figure 3 is an example of the light distribution pattern of the high beam irradiation light emitted from the headlamp 60. Note that the light distribution pattern shown in Figure 3 is the combined irradiation light of the left headlamp 60L and the right headlamp 60R. The area surrounded by the broken line X in Figure 3 indicates the irradiation area by the high beam irradiation of the headlamp 60. Note that the broken line X in Figure 3B indicates the irradiation area of the high beam projected on a virtual vertical screen at a predetermined position in front of the vehicle VH.

[0025] When the headlight control unit 100 obtains, based on the detection result of the external sensor device 40, for example, an oncoming vehicle VH2 as a dimming target object, the high beam of the light distribution pattern that shields or dims the area corresponding to the position of the oncoming vehicle VH2 is irradiated from the headlight 60. Hereinafter, the area where the high beam by the headlight 60 is shielded or dimmed is referred to as the "dimming area A". Also, the area where the high beam is irradiated by the headlight 60 is referred to as the "irradiation area B".

[0026] The object recognition unit 110 is the object recognition means of the present disclosure, and recognizes an object existing in front of the vehicle VH based on the image data transmitted from the camera 42 of the external sensor device 40. Specifically, when the illuminance around the own vehicle VH obtained by the light sensor 50 exceeds a predetermined illuminance in a bright area, the object recognition unit 110 performs image processing on the image data transmitted from the camera 42 by applying a bright area filter that increases the sharpness of the contour edges of the object image in the bright area, thereby recognizing the object in the image data.

[0027] Also, when the illuminance obtained by the light sensor 50 is equal to or less than the predetermined illuminance and the light distribution control unit 100 is not performing light distribution control, and the low beam is irradiated from the headlight 60, the object recognition unit 110 performs image processing on the image data transmitted from the camera 42 by applying a low beam filter that increases the sharpness of the contour edges of the object image in the low beam irradiation area, thereby recognizing the object in the image data. Also, when the illuminance obtained by the light sensor 50 is equal to or less than the predetermined illuminance and the light distribution control unit 100 is not performing light distribution control, and the high beam is irradiated from the headlight 60, the object recognition unit 110 performs image processing on the image data transmitted from the camera 42 by applying a high beam filter that increases the sharpness of the contour edges of the object image in the high beam irradiation area, thereby recognizing the object in the image data.

[0028] Incidentally, if image processing is performed by uniformly applying a high-beam filter (or a low-beam filter) during the execution of the light distribution control by the light distribution control unit 100, as shown in FIG. 4A, the luminance value of the target image (for example, oncoming vehicle VH2) existing in the dimming region A will be insufficient. For this reason, there is a possibility that the target recognition unit 110 may cause false detection or non-detection where it cannot recognize the target actually existing in the dimming region A.

[0029] In order to prevent false detection or non-detection of a target existing in the dimming region A during the execution of the light distribution control, the target recognition unit 110 performs image processing using different filters in the dimming region A and the irradiation region B. Specifically, the irradiation / dimming region specifying unit 120 specifies, based on the information of the light distribution control by the light distribution control unit 100, a dimming region A where the high beam of the headlamp 60 is shielded or dimmed and an irradiation region B where the high beam of the headlamp 60 is irradiated on the image data. For the irradiation region B in the image data specified by the irradiation / dimming region specifying unit 120, the target recognition unit 110 performs image processing by applying a high-beam filter to recognize the target existing in the irradiation region B in the image data. On the other hand, as shown in FIG. 4B, for the dimming region A in the image data specified by the irradiation / dimming region specifying unit 120, the target recognition unit 110 performs image processing by applying a dimming-region filter that increases the luminance value of the image data and enhances the sharpness of the contour edges of the target image. Thereby, the possibility of recognizing the target existing in the dimming region A can be increased, and it becomes possible to effectively prevent non-detection and false detection.

[0030] The PCS control unit 130 is a collision avoidance control means of the present disclosure, and executes PCS control for avoiding a collision between the host vehicle VH and a preceding target or reducing the damage of a collision. The PCS control unit 130 determines whether or not there is a target (hereinafter referred to as a target object) to be subjected to PCS control in front of the host vehicle VH based on the information of the target recognized by the target recognition unit 110. When it is determined that a target object exists, the PCS control unit 130 acquires the coordinate information of the target object based on the detection result of the external sensor device 40. Further, the PCS control unit 130 calculates the turning radius of the host vehicle VH based on the detection results of the vehicle speed sensor 31, the steering angle sensor 34, and the yaw rate sensor 36, and calculates the trajectory of the host vehicle VH based on this turning radius. The PCS control unit 130 determines whether or not a target object in front of the host vehicle VH is an obstacle that may collide with the host vehicle VH. When the target object is a moving object, the PCS control unit 130 calculates the trajectory of the target object based on the coordinate information of the target object, and determines the target object as an obstacle when the trajectory of the target object and the trajectory of the host vehicle VH intersect. Further, when the target object is a stationary object, the PCS control unit 130 determines the target object as an obstacle when the trajectory of the host vehicle VH intersects the current position of the target object.

[0031] When the PCS control unit 130 determines that the target object is an obstacle, it calculates the time to collision (hereinafter referred to as TTC) until the host vehicle VH collides with the obstacle based on the distance L from the host vehicle VH to the obstacle and the relative speed Vr of the host vehicle VH with respect to the obstacle. TTC is an index value indicating the possibility of the host vehicle VH colliding with the obstacle. TTC can be obtained by dividing the distance L from the host vehicle VH to the obstacle by the relative speed Vr (TTC = L / Vr). When TTC is equal to or less than a predetermined collision determination threshold value Tv, the PCS control unit 130 determines that the possibility of the host vehicle VH colliding with the obstacle is high. In the present embodiment, the target recognition unit 110 performs image processing of applying a filter for a dimming area that increases the luminance value of the image data to the dimming area A in the image data to clarify the contour edge of the target image, thereby recognizing the target in the dimming area A. That is, even when an obstacle that is the target of PCS control exists in the dimming area A, it is configured to effectively prevent the non-detection or mis-detection of the obstacle. Thereby, it becomes possible to surely improve the accuracy of the collision determination of the PCS control.

[0032] When the PCS control unit 130 determines that the possibility of the host vehicle VH colliding with the obstacle is high, it executes an alarm by the speaker 72 and / or the display device 71 and executes automatic brake control. The automatic brake control is a control for decelerating the host vehicle VH so that the deceleration of the host vehicle VH matches a predetermined target deceleration by controlling the operation of the braking device 22 and / or the driving device 20. Thereby, the host vehicle VH can be forcibly decelerated without requiring the driver to operate the brake pedal.

[0033] Next, based on FIG. 4, the routine of the target recognition process by the CPU 11 of the ECU 10 and the PCS control process will be described.

[0034] In step S100, the ECU 10 determines whether the illuminance around the vehicle VH is equal to or less than a predetermined illuminance based on the illuminance information acquired by the light sensor 50. If the illuminance around the vehicle VH is equal to or less than the predetermined illuminance (Yes), that is, in a dark place, the ECU 10 proceeds to the process of step S110. On the other hand, if the illuminance around the vehicle VH is not equal to or less than the predetermined illuminance (No), that is, in a bright place, the ECU 10 proceeds to the process of step S160.

[0035] In step S160, the ECU 10 recognizes the target in the image data by performing image processing in which a bright-place filter is applied to the image data acquired by the camera 42.

[0036] When proceeding from step S100 to the process of step S110, the ECU 10 determines whether a specific condition is satisfied in which the light distribution control of the headlamp 60 is being executed and at least a part of the irradiation light of the headlamp 60 is blocked or dimmed. If the specific condition is satisfied, the ECU 10 proceeds to the process of step S120. On the other hand, if the specific condition is not satisfied (No), the ECU 10 proceeds to the process of step S140.

[0037] In step S140, the ECU 10 determines whether the headlamp 60 is irradiating high beam. If the headlamp 60 is irradiating high beam (Yes), the ECU 10 proceeds to the process of step S150. On the other hand, if the headlamp 60 is not irradiating high beam (No), that is, if the headlamp 60 is irradiating low beam, the ECU 10 proceeds to the process of step S155.

[0038] In step S150, the ECU 10 recognizes the target in the image data by performing image processing in which a high-beam filter is applied to the image data acquired by the camera 42. On the other hand, in step S155, the ECU 10 recognizes the target in the image data by performing image processing in which a low-beam filter is applied to the image data acquired by the camera 42.

[0039] When proceeding to the process from step S110 to step S120, the ECU 10 identifies a dimming region A where the high beam of the headlamp 60 is shielded or dimmed and an irradiation region B where the high beam of the headlamp 60 is irradiated on the image data. Next, in step S130, the ECU 10 performs image processing by applying a filter for the dimming region to the dimming region A in the image data to recognize the target in the image data. Also, in step S135, the ECU 10 performs image processing by applying a filter for the high beam to the irradiation region B in the image data to recognize the target in the image data. Note that the processes in step S130 and step S135 may be in any order and may be performed simultaneously.

[0040] When proceeding to the process from step S135 or step S150 or step S155 or step S160 to step S170, the ECU 10 determines whether the target recognized by the image processing is a target for PCS control existing in front of the host vehicle VH. If the recognized target is a target for PCS control (Yes), the ECU 10 proceeds to the process in step S175. On the other hand, if the recognized target is not a target for PCS control (No), the ECU 10 returns to this routine.

[0041] In step S175, the ECU 10 determines whether the target object recognized in the process of step S170 is an obstacle. When the target object is a moving object, the ECU 10 determines the target object as an obstacle when the trajectory of the target object intersects with the trajectory of the host vehicle VH. Also, when the target object is a stationary object, the ECU 10 determines the target object as an obstacle when the trajectory of the host vehicle VH intersects with the current position of the target object. If the ECU 10 determines that the target object is an obstacle (Yes), it proceeds to the process in step S180. On the other hand, if the ECU 10 determines that the target object in front of the host vehicle VH is not an obstacle (No), it returns to this routine.

[0042] In step S180, the ECU 10 calculates TTC (= L / vr) by dividing the distance L from the host vehicle VH to the target object by the relative speed Vr. Next, in step S185, the ECU 10 determines whether the TTC is less than or equal to the collision determination threshold value Tv. When the TTC is less than or equal to the collision determination threshold value Tv (Yes), the ECU 10 proceeds to the process of step S190. On the other hand, when the TTC is greater than the collision determination threshold value Tv (No), the ECU 10 returns to this routine.

[0043] In step S190, the ECU 10 executes an alarm and performs automatic brake control to decelerate the host vehicle VH based on a predetermined target deceleration. After that, the ECU 10 returns to this routine.

[0044] As described above, the target recognition device according to this embodiment has been described. However, the present disclosure is not limited to the above embodiment, and various modifications are possible without departing from the object of the present disclosure.

[0045] For example, in the above embodiment, although it has been described that the target recognized by the target recognition unit 110 is applied to PCS control, it is also possible to apply it to other driving support controls such as follow - up inter - vehicle distance control (Adaptive Cruise Control: ACC) and lane - keeping support control (Lane Trace Asist: LTA). Further, the technology of the present disclosure can also be applied to an autonomous vehicle that automatically performs part or all of the driving operations.

Claims

1. Imaging means for imaging a predetermined range in front of the vehicle, A target recognition device comprising target recognition means for recognizing the presence of a target in the captured image by performing predetermined image processing on the captured image captured by the imaging means, Region specifying means for specifying, by means of light distribution control means for controlling the irradiation range of irradiation light emitted from a headlamp provided in the vehicle, a dimming region which is a region where the irradiation light is shielded or dimmed, and an irradiation region where the irradiation light is not shielded or dimmed, respectively, The target recognition means performs first image processing in the irradiation region respectively specified by the region specifying means, and performs second image processing for increasing the luminance of the captured image as compared with the first image processing in the dimming region respectively specified by the region specifying means. A target recognition device characterized by the above.

2. The target recognition device according to Claim 1, In the dimming region, the target recognition means performs the second image processing by applying a filter for enhancing the luminance of the captured image to clarify the contour edge of the target image. A target recognition device characterized by the above.

3. The target recognition device according to Claim 1 or 2, The vehicle is provided with collision avoidance control means for performing collision avoidance control for avoiding a collision between the vehicle and the object or reducing damage caused by the collision when an object recognized in front of the vehicle satisfies a predetermined collision condition, The target recognition means causes the collision avoidance control means to recognize the object by transmitting information on the recognized target to the collision avoidance control means. A target recognition device characterized by the above.

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