Brake light illumination determination device, brake light illumination determination computer program, and brake light illumination determination method

Abstract

To provide a brake light lighting determination device capable of detecting lighting of a brake light of a front vehicle in a short time and determining it with high accuracy.SOLUTION: A brake light lighting determination device comprises: a speed detection unit 230 that detects a reduction in a speed of a front vehicle based on output information of a sensor for acquiring information about the front vehicle located in front of a vehicle; a lighting identification unit 231 that identifies that the brake light of the front vehicle is lighting based on an image representing a front view of the vehicle; and a braking determination unit 233 for determining that the front vehicle is braking when the lighting identification unit 231 identifies that the brake light of the front vehicle is lighting as to the front vehicle where a speed reduction timing at which the speed reduction is detected by the speed detection unit 230 and a lighting timing at which the lighting of the brake light of the front vehicle is identified by the lighting identification unit 231 are synchronized with each other.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a brake light illumination determination device, a brake light illumination determination computer program, and a brake light illumination determination method. [Background technology]

[0002] An automatic control system installed in a vehicle generates a driving route for the vehicle based on the current position of the vehicle, the destination position of the vehicle, and map information, and controls the vehicle to travel along this driving route.

[0003] The automatic control system controls the vehicle so as to maintain a predetermined distance or more between the vehicle and other surrounding vehicles. Therefore, the automatic control system is required to detect the deceleration of the preceding vehicle at an early stage so as to maintain a predetermined distance or more even when the preceding vehicle traveling in front of the vehicle decelerates.

[0004] The deceleration of the vehicle ahead can be detected by using a sensor such as a LiDAR sensor or a radar sensor, or by identifying whether the brake lights of the vehicle ahead are on based on an image captured in front of the vehicle (see, for example, Patent Document 1).

[0005] Identifying whether the brake lights of a forward vehicle are on based on an image requires less processing time than detecting the deceleration of the forward vehicle using a sensor such as a LiDAR sensor or a radar sensor. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2017-174204 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, the brake lights of the vehicle ahead may be identified as being on even if they are not on because they reflect light such as sunlight. For this reason, the accuracy of identifying whether the brake lights of the vehicle ahead are on based on an image may be insufficient.

[0008] Therefore, an object of the present disclosure is to provide a brake light illumination determination device that can detect in a short period of time and determine with high accuracy that the brake lights of a forward vehicle are illuminated. [Means for solving the problem]

[0009] (1) According to one embodiment, there is provided a brake light illumination determination device, which is characterized by having: a speed detection unit that detects a reduction in the speed of a forward vehicle based on output information from a sensor that acquires information about a forward vehicle located in front of the vehicle; an illumination identification unit that identifies that the brake lights of the forward vehicle are illuminated based on an image showing the front of the vehicle; and a determination unit that determines that the forward vehicle is braking when the illumination identification unit identifies that the brake lights of the forward vehicle are illuminated for a forward vehicle in which the speed reduction timing at which the speed detection unit detects a speed reduction is synchronized with the illumination timing at which the illumination identification unit identifies the illumination of the brake lights of the forward vehicle.

[0010] (2) In the lighting determination device of (1), it is preferable that the determination unit determines that the speed reduction timing and the lighting timing are synchronized when the period during which a speed reduction change equal to or greater than a predetermined reference reduction amount is detected coincides with the period during which the brake lights of the forward vehicle are identified as being on.

[0011] (3) In the lighting determination device of (1) or (2), when the vehicle in front changes to another vehicle, it is preferable that the determination unit re-executes the determination as to whether the speed reduction timing and the lighting timing are synchronized.

[0012] (4) In any of the lighting determination devices (1) to (3), when the environment around the vehicle changes, it is preferable that the determination unit re-executes the determination as to whether the speed reduction timing and the lighting timing are synchronized.

[0013] (5) According to another embodiment, there is provided a computer program for determining whether brake lights are on. This computer program causes a processor to detect a reduction in speed of a forward vehicle based on output information from a sensor that acquires information about a forward vehicle located in front of the vehicle, identify that the brake lights of the forward vehicle are on based on an image showing the front of the vehicle, and determine that the forward vehicle is braking when it is identified that the brake lights of the forward vehicle are on for a forward vehicle in which the speed reduction timing at which the reduction in speed of the forward vehicle was detected is synchronized with the timing at which the brake lights of the forward vehicle were identified.

[0014] (6) According to another embodiment, there is provided a method for determining whether brake lights are on, which detects a reduction in the speed of a forward vehicle based on output information from a sensor that acquires information about a forward vehicle located in front of the vehicle, identifies that the brake lights of the forward vehicle are on based on an image showing the front of the vehicle, and determines that the forward vehicle is braking when it is identified that the brake lights of the forward vehicle are on for a forward vehicle whose speed reduction timing at which the reduction in speed of the forward vehicle is detected is synchronized with the timing at which the brake lights of the forward vehicle are identified. The above is characterized in that the brake light illumination determination device executes the above steps. Effect of the Invention

[0015] The brake light illumination determination device according to the present disclosure can detect in a short time and with high accuracy that the brake lights of a forward vehicle are illuminated. [Brief description of the drawings]

[0016] [Figure 1] 1 is a diagram for explaining an overview of the operation of a vehicle control system including a lighting determination device of the present embodiment. [Diagram 2] 1 is a schematic configuration diagram of a vehicle in which a lighting determination device according to an embodiment of the present invention is implemented; [Diagram 3] 5 is an example of an operational flowchart relating to a lighting determination process of the lighting determination device of the present embodiment. [Figure 4] 5 is an example of an operational flowchart relating to a start condition determination process of the lighting determination device of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] 1 is a diagram for explaining an outline of the operation of a vehicle control system 1 including a lighting determination device 17 of this embodiment. Hereinafter, an outline of the operation of the lighting determination device 17 disclosed in this specification regarding the traffic congestion determination process will be described with reference to FIG.

[0018] A vehicle 10 is traveling on a road 50. Ahead of the vehicle 10 is a leading vehicle 60 traveling in the same lane as the vehicle 10.

[0019] When the vehicle 60 in front decelerates, the lighting determination device 17 detects the reduction in speed of the vehicle 60 in front based on reflected wave information contained in the reflected wave that is the emission wave emitted from the LiDAR sensor 3 and reflected by the vehicle 60 in front.

[0020] In addition, when the brake lights 61 are turned on due to the braking of the preceding vehicle 60, the lighting determination device 17 identifies that the brake lights 61 of the preceding vehicle 60 are turned on based on the camera image 70 showing the front of the vehicle 10 captured by the camera 2.

[0021] When the light-on determination device 17 detects a reduction in the speed of the vehicle 60 ahead based on the reflected wave information and identifies that the brake lights 61 of the vehicle 60 ahead are on based on the camera image 70, it determines whether or not the speed reduction timing at which the reduction in the speed of the vehicle 60 ahead is detected is synchronized with the lighting timing at which the brake lights of the vehicle 60 ahead are identified as being on.

[0022] The fact that the timing of the speed reduction when a reduction in the speed of the vehicle 60 in front is detected is synchronized with the timing of the brake lights of the vehicle 60 being identified as being on means that, for this vehicle 60 in front, it is possible to identify with high accuracy that the brake lights 61 of the vehicle 60 in front are on, based on the camera image 70.

[0023] Therefore, when it is identified that the brake lights of the forward vehicle 60 are on for the forward vehicle 60 in which the speed reduction timing at which a reduction in the speed of the forward vehicle 60 is detected is synchronized with the lighting timing at which the brake lights of the forward vehicle 60 are identified, the lighting determination device 17 determines that the forward vehicle 60 is braking. Since the lighting determination device 17 identifies that the brake lights of the forward vehicle 60 are on based on the camera image 70, it is possible to detect the start of deceleration of the forward vehicle 60 in a short time.

[0024] This allows the light-on determination device 17 to detect that the brake lights are turned on in a short time and improve the determination accuracy.

[0025] 2 is a schematic configuration diagram of a vehicle 10 in which the vehicle control system 1 is implemented. The vehicle control system 1 includes a camera 2, a LiDAR sensor 3, a positioning information receiver 4, a navigation device 5, a user interface (UI) 6, a raindrop sensor 7, a map information storage device 11, a position estimation device 12, an object detection device 13, a driving lane planning device 14, a driving planning device 15, a vehicle control device 16, a lighting determination device 17, and the like. Furthermore, the vehicle control system 1 may include other distance measurement sensors (not shown) such as a radar sensor for measuring distances to objects around the vehicle 10.

[0026] The camera 2, LiDAR sensor 3, positioning information receiver 4, navigation device 5, UI 6, raindrop sensor 7, map information storage device 11, position estimation device 12, object detection device 13, driving lane planning device 14, driving planning device 15, vehicle control device 16, and lighting determination device 17 are communicatively connected via an in-vehicle network 18 that complies with a standard such as a controller area network.

[0027] The camera 2 is attached to the vehicle 10 so as to face the front of the vehicle 10. The camera 2 captures a camera image showing the environment of a predetermined area in front of the vehicle 10, for example, at a predetermined cycle. The road included in the predetermined area in front of the vehicle 10 and road features such as lane markings on the road surface may be shown in the camera image. The camera image captured by the camera 2 may show a forward vehicle located in front of the vehicle 10. The camera 2 is an example of a sensor that acquires information about a forward vehicle located in front of the vehicle 10. The camera 2 has a two-dimensional detector composed of an array of photoelectric conversion elements sensitive to visible light, such as a CCD or a C-MOS, and an imaging optical system that forms an image of the area to be captured on the two-dimensional detector. The camera image is an example of output information of a sensor that acquires information about a forward vehicle 60 located in front of the vehicle 10.

[0028] Every time the camera 2 captures a camera image, it outputs the camera image and the camera image capture time at which the camera image was captured to the position estimation device 12, the object detection device 13, etc. via the in-vehicle network 18. The camera image is used by the position estimation device 12 in a process of estimating the position of the vehicle 10. The camera image is also used by the object detection device 13 in a process of detecting other objects around the vehicle 10.

[0029] The LiDAR sensor 3 is attached to, for example, the outer surface of the vehicle 10 so as to face the front of the vehicle 10. The LiDAR sensor 3 emits a pulsed laser toward the front of the vehicle 10 at a reflected wave information acquisition time set at a predetermined cycle, and receives a reflected wave reflected by a reflecting object. The time required for the reflected wave to return contains distance information between the vehicle 10 and other objects located in the direction of the laser irradiation. The LiDAR sensor 3 is an example of a sensor that acquires information about a forward vehicle located in front of the vehicle 10. The LiDAR sensor 3 outputs reflected wave information including the laser irradiation direction and the time required for the reflected wave to return, together with the reflected wave information acquisition time when the laser was emitted, to the object detection device 13 via the in-vehicle network 18. The reflected wave information is used in the object detection device 13 for processing to detect other objects around the vehicle 10. The reflected wave information is an example of output information of a sensor that acquires information about a forward vehicle 60 located in front of the vehicle 10.

[0030] The positioning information receiver 4 outputs positioning information indicating the current position of the vehicle 10. For example, the positioning information receiver 4 may be a GNSS receiver. Every time the positioning information receiver 4 acquires positioning information at a predetermined reception cycle, the positioning information receiver 4 outputs the positioning information and the positioning information acquisition time when the positioning information was acquired to the navigation device 5, the map information storage device 11, etc.

[0031] The navigation device 5 generates a navigation route from the current position of the vehicle 10 to the destination position based on the navigation map information, the destination position of the vehicle 10 input from the UI 6, and the positioning information indicating the current position of the vehicle 10 input from the positioning information receiver 4. The navigation device 5 generates a new navigation route for the vehicle 10 when a new destination position is set or when the current position of the vehicle 10 deviates from the navigation route. Every time the navigation device 5 generates a navigation route, it outputs the navigation route to the position estimation device 12, the driving lane planning device 14, etc. via the in-vehicle network 18.

[0032] The UI 6 is an example of a notification unit. The UI 6 is controlled by the navigation device 5 or the like to notify the driver of driving information of the vehicle 10. The UI 6 also generates an operation signal according to an operation from the driver to the vehicle 10. The driving information of the vehicle 10 includes information on the current and future routes of the vehicle, such as the current position of the vehicle and a navigation route. The UI 6 has a display device 6a such as a liquid crystal display or a touch panel to display the driving information. The UI 6 may also have an audio output device (not shown) for notifying the driver of the driving information. The UI 6 also has, for example, a touch panel or an operation button as an input device for inputting operation information from the driver to the vehicle 10. Examples of the operation information include a destination position, a waypoint, a vehicle speed, and other control information of the vehicle 10. The UI 6 outputs the input operation information to the navigation device 5 and the vehicle control device 16 via the in-vehicle network 18.

[0033] The raindrop sensor 7 detects raindrops. The raindrop sensor 7 outputs information indicating whether or not raindrops have been detected to the lighting determination device 17 via the in-vehicle network 18. The raindrop sensor 7 is an example of a sensor that acquires information about the environment around the vehicle 10. A light reflection sensor can be used as the raindrop sensor 7.

[0034] The map information storage device 11 stores map information of a relatively wide area (for example, a range of 10 to 30 km square) including the current position of the vehicle 10. This map information has three-dimensional information of the road surface, information representing the types and positions of road features and structures such as lane markings on the road, and high-precision map information including the legal speed limit of the road. The map information storage device 11 receives wide-area map information from an external server via a base station by wireless communication via a wireless communication device (not shown) mounted on the vehicle 10 according to the current position of the vehicle 10, and stores the received map information in the storage device. Each time positioning information is input from the positioning information receiver 4, the map information storage device 11 refers to the stored wide-area map information, and outputs map information of a relatively small area (for example, a range of 100 m to 10 km square) including the current position represented by the positioning information to the position estimation device 12, the object detection device 13, the driving lane planning device 14, the driving planning device 15, the vehicle control device 16, and the like via the in-vehicle network 18.

[0035] The position estimation device 12 estimates the position of the vehicle 10 at the time the camera image is captured, based on road features around the vehicle 10 shown in the camera image captured by the camera 2. For example, the position estimation device 12 compares lane markings identified in the camera image with lane markings shown in the map information input from the map information storage device 11, and determines an estimated position and an estimated azimuth angle of the vehicle 10 at the time the camera image is captured. The position estimation device 12 also estimates the driving lane on the road on which the vehicle 10 is located, based on the lane markings shown in the map information, and the estimated position and estimated azimuth angle of the vehicle 10. Every time the position estimation device 12 determines the estimated position, estimated azimuth angle, and driving lane of the vehicle 10 at the time the camera image is captured, it outputs this information to the object detection device 13, the driving lane planning device 14, the driving planner 15, the vehicle control device 16, etc.

[0036] The object detection device 13 detects other objects and their types in front of the vehicle 10 located within a predetermined range from the vehicle 10 based on the camera image captured by the camera 2. The other objects include other vehicles traveling around the vehicle 10. The object detection device 13 has, for example, a first classifier that detects an object shown in the image by inputting a camera image. As the first classifier, for example, a deep neural network (DNN) that has been trained in advance to detect an object shown in an input image from the image can be used. The object detection device 13 may use a classifier other than a DNN. For example, the object detection device 13 may use, as the classifier, a support vector machine (SVM) that has been trained in advance to input a feature amount (for example, Histograms of Oriented Gradients, HOG) calculated from a window set on the camera image and output a confidence that the object to be detected is shown in the window. Alternatively, the object detection device 13 may detect an object region by performing template matching between a template in which the object to be detected is shown and the image.

[0037] Furthermore, the object detection device 13 has a second classifier that detects that the brake lights of the forward vehicle are on by inputting an image of the area in the camera image where the forward vehicle is detected when the forward vehicle is detected in the camera image. As the second classifier, for example, a deep neural network (DNN) that is trained in advance to detect that the brake lights of the forward vehicle shown in the input image are on can be used. When the forward vehicle is detected in the camera image, the object detection device 13 detects that the brake lights of the forward vehicle are on by inputting an image of the area in the camera image where the forward vehicle is detected in the second classifier. Note that the first classifier may detect that the brake lights of the forward vehicle are on.

[0038] When the first classifier detects a forward vehicle in the camera image, the object detection device 13 may input an image of the area in the camera image where the forward vehicle is detected to the second classifier only when it is determined that the forward vehicle is included in an area where the forward vehicle is considered to be traveling in the same lane as the vehicle 10. This makes it possible to avoid detecting that the brake lights of another vehicle traveling in an adjacent lane adjacent to the traveling lane in which the vehicle 10 is traveling are turned on. The area in the camera image where the forward vehicle is considered to be traveling in the same lane as the vehicle 10 is determined based on the installation conditions of the camera 2, etc.

[0039] Furthermore, the object detection device 13 detects other objects in front of the vehicle 10 based on the reflected wave information output by the LiDAR sensor 3. The object detection device 13 determines the direction of the other object relative to the vehicle 10 based on the position of the other object in the camera image, and determines the distance between the other object and the vehicle 10 based on the direction and the reflected wave information output by the LiDAR sensor 3. The object detection device 13 estimates the position of the other object, for example, expressed in a world coordinate system, based on the current position of the vehicle 10 and the distance and direction to the other object relative to the vehicle 10. The object detection device 13 also tracks the other object detected from the latest image by associating the other object detected from the latest camera image with the object detected from the past image according to a tracking process based on optical flow. Then, the object detection device 13 determines the trajectory of the other object being tracked based on the position of the object in the latest image from the past image expressed in the world coordinate system. The object detection device 13 estimates the speed of the other object relative to the vehicle 10 based on the change in the position of the other object over time. The object detection device 13 obtains the speed of the object relative to the ground based on the estimated speed of the object relative to the vehicle 10 and the speed of the vehicle 10. The object detection device 13 can also estimate the acceleration of the other object based on the change in the speed of the other object over time. Furthermore, the object detection device 13 identifies the lane in which the other object is traveling based on the lane markings shown in the map information and the position of the other object. For example, the object detection device 13 determines that the other object is traveling in a lane identified by two adjacent lane markings located on either side of the horizontal center position of the other object. The object detection device 13 outputs object detection information including information indicating the type of the detected other object, information indicating its position, speed, acceleration, and traveling lane to the lane planning device 14, the driving planning device 15, the vehicle control device 16, etc. The detection range in which the object detection device 13 can detect the other object is determined based on the installation conditions and resolution of the camera 2 and the LiDAR sensor 3, etc.

[0040] When another object travels in the same lane as the vehicle 10, the object detection device 13 determines that the object is a forward vehicle. When the object detection device 13 detects a forward vehicle, it attaches vehicle identification information for identifying the vehicle to the forward vehicle and tracks the forward vehicle. The object detection device 13 outputs object detection information with information indicating that the other object is a forward vehicle, information indicating whether the forward vehicle has its brake lights on or not, and vehicle identification information of the forward vehicle to the light-on determination device 17. When the object detection device 13 does not detect a forward vehicle to which it previously attached vehicle identification information for a predetermined period of time, it determines that it has lost sight of the forward vehicle. When the object detection device 13 detects a new forward vehicle thereafter, it attaches new vehicle identification information to the new forward vehicle and tracks the new forward vehicle.

[0041] The driving lane planning device 14 generates a driving lane plan representing a planned driving lane on which the vehicle 10 will travel, based on map information, the navigation route and surrounding environment information, and the current position of the vehicle 10, in the nearest driving section (e.g., 10 km) selected from the navigation route at a driving lane plan generation time set at a predetermined cycle. The driving lane planning device 14 generates a driving lane plan so that the vehicle 10 travels on a lane other than an overtaking lane, for example. The driving lane planning device 14 outputs the driving lane plan to the driving planning device 15 every time it generates a driving lane plan.

[0042] In addition, the driving lane planning device 14 determines whether or not a lane change is required in the nearest driving section selected from the navigation route based on the driving lane plan, map information, the navigation route, and the current position of the vehicle 10, and generates a lane change plan according to the determination result. The lane change plan includes a planned lane change section in which the vehicle 10 is scheduled to move to an adjacent lane on the lane on which the vehicle 10 is traveling. Specifically, the driving lane planning device 14 determines whether or not a lane change is required to move to a lane leading to the destination position of the vehicle 10 based on the navigation route and the current position of the vehicle 10. The driving lane planning device 14 determines whether or not the vehicle 10 will enter another road at a junction from the traveling road on which the vehicle 10 is currently traveling (merging) and whether or not the vehicle 10 will exit from the traveling road to another road at a branching point (branching). At merging and branching, the vehicle moves from a lane of the traveling road to a lane of another road, so a lane change is performed. The driving lane planning device 14 may further use surrounding environment information or vehicle state information to determine whether or not a lane change is required. The surrounding environment information includes the positions and speeds of other vehicles traveling around the vehicle 10. The vehicle state information includes the current position, vehicle speed, acceleration, and traveling direction of the vehicle 10. The driving lane planning device 14 also generates a lane change plan in response to a request from the driver. Information representing the vehicle speed and acceleration of the vehicle 10 is acquired using a sensor (not shown) mounted on the vehicle 10.

[0043] The driving plan device 15 executes a driving plan process to generate a driving plan representing a planned driving trajectory of the vehicle 10 up to a predetermined time (for example, 5 seconds) ahead based on a driving lane plan, map information, the current position of the vehicle 10, surrounding environment information, and vehicle state information at a driving plan generation time set at a predetermined cycle. The driving plan is expressed as a set of a target position of the vehicle 10 and a target vehicle speed at the target position at each time from the current time to the predetermined time ahead. The cycle in which the driving plan is generated is preferably shorter than the cycle in which the driving lane plan is generated. The driving plan device 15 generates a driving plan so as to maintain a distance of at least a predetermined distance between the vehicle 10 and another vehicle. The driving plan device 15 outputs the driving plan to the vehicle control device 16 every time the driving plan is generated.

[0044] The vehicle control device 16 controls each part of the vehicle 10 based on the current position, the vehicle speed, the yaw rate, and the driving plan generated by the driving plan device 15. For example, the vehicle control device 16 calculates the steering angle, acceleration, and angular acceleration of the vehicle 10 according to the driving plan, the vehicle speed, and the yaw rate of the vehicle 10, and sets the steering amount, the accelerator opening, or the brake amount so as to obtain the steering angle, acceleration, and angular acceleration. The vehicle control device 16 then outputs a control signal corresponding to the set steering amount to an actuator (not shown) that controls the steered wheels of the vehicle 10 via the in-vehicle network 18. The vehicle control device 16 also calculates a fuel injection amount according to the set accelerator opening, and outputs a control signal corresponding to the fuel injection amount to a drive device (not shown) such as an engine of the vehicle 10 via the in-vehicle network 18. Alternatively, the vehicle control device 16 outputs a control signal corresponding to the set brake amount to a brake (not shown) of the vehicle 10 via the in-vehicle network 18.

[0045] The lighting determination device 17 executes a speed detection process, a lighting identification process, an environment detection process, a synchronization determination process, and a braking determination process. To this end, the lighting determination device 17 has a communication interface (IF) 21, a memory 22, and a processor 23. The communication interface 21, the memory 22, and the processor 23 are connected via a signal line 24. The communication interface 21 has an interface circuit for connecting the lighting determination device 17 to the in-vehicle network 18.

[0046] All or part of the functions of the lighting determination device 17 are functional modules realized by a computer program running on the processor 23, for example. The processor 23 has a speed detection unit 230, a lighting identification unit 231, an environment detection unit 232, and a braking determination unit 233. The braking determination unit 233 is an example of a determination unit. Alternatively, the functional modules of the processor 23 may be dedicated arithmetic circuits provided in the processor 23. The processor 23 has one or more CPUs (Central Processing Units) and their peripheral circuits. The processor 23 may further have other arithmetic circuits such as a logic arithmetic unit, a numerical arithmetic unit, or a graphic processing unit. The memory 22 is an example of a storage unit, and has, for example, a volatile semiconductor memory and a non-volatile semiconductor memory. The memory 22 stores computer programs of applications and various data used in the information processing executed by the processor 23. Details of other operations in the lighting determination device 17 will be described later.

[0047] In FIG. 2, the map information storage device 11, the position estimation device 12, the object detection device 13, the driving lane planning device 14, the driving planning device 15, the vehicle control device 16, and the lighting determination device 17 are described as separate devices, but all or some of these devices may be configured as a single device.

[0048] Fig. 3 is an example of an operation flowchart relating to the lighting determination process of the lighting determination device 17 of this embodiment. Hereinafter, the lighting determination process of the lighting determination device 17 will be described with reference to Fig. 3. The lighting determination device 17 executes the lighting determination process according to the operation flowchart shown in Fig. 3 at lighting determination times having a predetermined cycle.

[0049] First, the braking determination unit 233 determines whether or not a start condition for performing synchronization determination is satisfied (step S101). This synchronization determination is to determine whether or not a speed reduction timing at which a reduction in the speed of the forward vehicle is detected is synchronized with a timing at which the light-on timing of the brake lights of the forward vehicle is identified. Details of the start condition determination process will be described later.

[0050] If the start condition is not satisfied (step S101-No), the series of processes ends. On the other hand, if the start condition is satisfied (step S101-Yes), the braking determination unit 233 determines whether or not the speed reduction timing at which a reduction in the speed of the forward vehicle is detected is synchronized with the lighting timing at which the brake lights of the forward vehicle are identified (step S102). Specifically, if the period at which a reduction in speed equal to or greater than a predetermined reference reduction amount is detected coincides with the period at which the brake lights of the forward vehicle are identified as being on, the braking determination unit 233 determines that the speed reduction timing and the lighting timing are synchronized.

[0051] The predetermined reference speed reduction amount may be, for example, 0.686466 m / s. When a speed reduction of 0.686466 m / s continues for one second, a deceleration of 0.07 G occurs in the vehicle ahead.

[0052] It is considered that the time required to detect the speed reduction of the forward vehicle is longer than the time required to identify the brake lights of the forward vehicle. Therefore, the start point of the period in which the speed reduction change of the predetermined reference reduction amount or more is detected is delayed from the start point of the period in which it is identified that the brake lights of the forward vehicle are on, and the end point of the period in which the speed reduction change of the predetermined reference reduction amount or more is detected is delayed from the end point of the period in which it is identified that the brake lights of the forward vehicle are on. Therefore, if the difference between the start point of the period in which the speed reduction change of the predetermined reference reduction amount or more is detected and the start point of the period in which it is identified that the brake lights of the forward vehicle are on is within a predetermined allowable time, and the difference between the end point of the period in which the speed reduction change of the predetermined reference reduction amount or more is detected and the end point of the period in which it is identified that the brake lights of the forward vehicle are on is within a predetermined allowable time, the braking determination unit 233 determines that the two periods match. The allowable time can be, for example, 0.01 to 0.5 seconds. The conditions under which the braking determination unit 233 determines whether the speed reduction timing and the lighting timing are synchronized are not limited to those described above.

[0053] When it is determined that the speed reduction timing and the lighting timing are synchronized (step S102-Yes), the braking determination unit 233 decides to determine that the forward vehicle, whose brake lights have been identified as being on by the lighting identification unit 231, is braking, and the series of processes ends (step S103). After this determination is made, when the lighting identification unit 231 identifies that the brake lights of the forward vehicle are on while the vehicle 10 is traveling, the braking determination unit 233 determines that the forward vehicle is braking.

[0054] On the other hand, if it is determined that the speed reduction timing and the illumination timing are not synchronized (step S102-No), and if the speed detection unit 230 detects a speed reduction of the forward vehicle equal to or greater than a predetermined reference reduction amount, the braking determination unit 233 decides to determine that the forward vehicle is braking, and the series of processes ends (step S104). After this determination is made, if the speed detection unit 230 detects a speed reduction of the forward vehicle equal to or greater than a predetermined reference reduction amount while the vehicle 10 is traveling, the braking determination unit 233 determines that the forward vehicle is braking.

[0055] Fig. 4 is an example of an operational flowchart relating to the start condition determination process of the lighting determination device 17 of this embodiment. Hereinafter, the start condition determination process of the lighting determination device 17 will be described with reference to Fig. 4. The lighting determination device 17 executes vehicle control processing according to the operational flowchart shown in Fig. 4 at a start condition determination time having a predetermined period. It is preferable that the period of the start condition determination time is the same as or shorter than the period of the lighting determination time described above.

[0056] First, the speed detection unit 230 determines whether or not a forward vehicle has been detected based on the object detection information of the forward vehicle input from the object detection device 13 (step S201).

[0057] When a forward vehicle is detected (step S201-Yes), the speed detection unit 230 determines whether or not a decrease in the speed of the forward vehicle that is equal to or greater than a predetermined reference decrease amount has been detected (step S202) based on the object detection information of the forward vehicle input from the object detection device 13. The predetermined reference decrease amount of the speed may be set to 0.686466 m / s as described above.

[0058] If a reduction in the speed of the forward vehicle is detected by more than a predetermined standard reduction amount (step S202-Yes), the light identification unit 231 determines whether the brake lights of the forward vehicle are on or not based on information input from the object detection device 13 indicating whether the brake lights of the forward vehicle are on or not (step S203).

[0059] If it is determined that the brake lights of the forward vehicle are on (step S203-Yes), the braking determination unit 233 determines that the start condition for performing synchronization determination is satisfied, and ends the series of processes (step S206).

[0060] When a decrease in the speed of the forward vehicle equal to or greater than a predetermined reference decrease amount is not detected (step S202-No), the braking determination unit 233 determines whether the forward vehicle has changed to another vehicle based on the vehicle identification information of the forward vehicle input from the object detection device 13 (step S204). When the vehicle identification information of the forward vehicle input from the object detection device 13 is different from previously input vehicle identification information, the braking determination unit 233 determines that the forward vehicle has changed to another vehicle. On the other hand, when the vehicle identification information of the forward vehicle input from the object detection device 13 is the same as previously input vehicle identification information, the braking determination unit 233 determines that the forward vehicle has not changed to another vehicle.

[0061] When the vehicle ahead is changed to another vehicle (step S204-Yes), the braking determination unit 233 determines that the start condition for performing synchronization determination is satisfied, and ends the series of processes (step S206). If the vehicle ahead is different, the state in which the brake lights are turned on may change in the image, which may affect the identification of the brake lights of the vehicle ahead being turned on. Therefore, when the vehicle ahead is changed to another vehicle, the lighting determination device 17 causes the braking determination unit 233 to perform a new determination as to whether the speed reduction timing and the lighting timing are synchronized.

[0062] If the vehicle ahead has not changed to another vehicle (step S204-No), the environment detection unit 232 determines whether the environment around the vehicle 10 has changed (step S204). The environment detection unit 232 determines that the environment around the vehicle 10 has changed when the state changes from a state where raindrops are not detected to a state where raindrops are detected, based on information indicating whether raindrops have been detected from the raindrop sensor 7 at present and in the past. The environment detection unit 232 also determines that the environment around the vehicle 10 has changed when the state changes from a state where raindrops are detected to a state where raindrops are not detected, based on information indicating whether raindrops have been detected from the raindrop sensor 7 at present and in the past. The environment detection unit 232 may determine that the environment around the vehicle 10 has changed when the brightness around the vehicle has changed. In this case, the environment detection unit 232 may determine the change in the brightness around the vehicle 10 based on output information of a sensor that detects the brightness around the vehicle 10. Furthermore, the environment detection unit 232 may determine that the environment around the vehicle 10 has changed when the vehicle 10 enters a tunnel or when the vehicle 10 exits a tunnel, based on map information.

[0063] If the environment around the vehicle 10 has changed (step S205-Yes), the braking determination unit 233 determines that the start condition for performing synchronization determination is satisfied, and ends the series of processes (step S206). The brightness of the surroundings differs when it is raining and when it is not raining, and is also affected by rain, so there is a risk that the discrimination that the brake lights of the vehicle ahead are on may be affected. Therefore, when the environment around the vehicle 10 has changed, the lighting determination device 17 causes the braking determination unit 233 to once again determine whether the speed reduction timing and the lighting timing are synchronized.

[0064] If the environment around the vehicle 10 has not changed (step S205-No) or if a vehicle ahead is not detected (step S201-No), the braking determination unit 233 determines that the start condition for performing synchronization determination is not satisfied, and ends the series of processes (step S207).

[0065] Next, the operation of the vehicle 10 when it is traveling on a road will be described below with reference to FIG.

[0066] The vehicle 10 is traveling on a road 50. When the brake lights of the forward vehicle 60 are identified as being on for the forward vehicle 60 whose speed reduction timing at which the speed reduction of the forward vehicle 60 is detected is synchronized with the light-on timing at which the brake lights of the forward vehicle 60 are identified, the light-on determination device 17 determines that the forward vehicle 60 is braking. For example, when it is determined that the forward vehicle 60 is braking, the vehicle control device 16 controls the vehicle 10 to stop accelerating if it was accelerating. Then, the driving plan device 15 generates a driving plan for the vehicle 10 so as to maintain a distance of a predetermined distance or more between the vehicle 10 and the forward vehicle 60.

[0067] On the other hand, for a forward vehicle 60 in which the speed reduction timing at which a reduction in the speed of the forward vehicle 60 is detected is not synchronized with the lighting timing at which the brake lights of the forward vehicle 60 are identified, the lighting determination device 17 determines that the forward vehicle is braking when a speed reduction of the forward vehicle equal to or greater than a predetermined standard reduction amount is detected.

[0068] The fact that the speed reduction timing at which a reduction in the speed of the forward vehicle 60 is detected and the lighting timing at which the lighting of the brake lights of the forward vehicle 60 is identified are not synchronized means that for this forward vehicle 60, it is not possible to accurately identify that the brake lights 61 of the forward vehicle 60 are on, based on the camera image 70. Therefore, the lighting determination device 17 uses a more accurate detection method to determine that the forward vehicle is braking.

[0069] The lighting determination device 17 detects a reduction in the speed of the forward vehicle 60 at each lighting determination time having a predetermined cycle, and when it identifies that the brake lights 61 of the forward vehicle 60 are on, it determines whether or not the speed reduction timing at which the reduction in the speed of the forward vehicle 60 is detected is synchronized with the lighting timing at which the lighting of the brake lights of the forward vehicle 60 is identified. In this way, the lighting determination device 17 incorporates the influence of environmental changes that cannot be detected by the environment detection unit 232 into the lighting determination, thereby improving the determination accuracy.

[0070] Furthermore, when the lighting determination device 17 determines that the forward vehicle 60 has changed to another vehicle, it again determines whether or not the speed reduction timing at which the speed reduction of the forward vehicle 60 is detected is synchronized with the lighting timing at which the lighting of the brake lights of the forward vehicle 60 is identified. This makes it possible to accurately detect that the forward vehicle has applied the brakes using the image, even when the vehicle has changed.

[0071] Furthermore, when the lighting determination device 17 determines that the environment around the vehicle 10 has changed, it again determines whether or not the speed reduction timing at which the reduction in speed of the forward vehicle 60 is detected is synchronized with the lighting timing at which the lighting of the brake lights of the forward vehicle 60 is identified. This makes it possible to accurately detect that the forward vehicle 60 has braked using images, even when the environment around the vehicle 10 has changed.

[0072] According to the lighting determination device of the present embodiment described above, it is possible to detect in a short time and to determine with high accuracy that the brake lights of the forward vehicle are turned on.

[0073] In the present disclosure, the lighting determination device, the lighting determination computer program, and the lighting determination method of the above-mentioned embodiments can be appropriately modified without departing from the spirit of the present disclosure. Furthermore, the technical scope of the present disclosure is not limited to those embodiments, but extends to the inventions described in the claims and their equivalents.

[0074] For example, when the vehicle ahead has not changed to another vehicle and the surrounding environment of the vehicle has not changed, the braking determination unit may change the identification reference value for the second classifier of the object detection device to detect that the brake lights of the vehicle ahead are on to a lower value than before, thereby enabling earlier detection of braking of the vehicle ahead. [Explanation of symbols]

[0075] 1 Vehicle Control System 2 Camera 3 LiDAR Sensor 4 Positioning information receiver 5. Navigation devices 6 User Interface 6a Display device 7 Rain sensor 10 Vehicles 11 Map information storage device 12 Position estimation device 13 Object detection device 14 Traffic lane planning device 15 Operation planning device 16 Vehicle control device 17 Lighting determination device 18 In-vehicle network 21 Communication Interface 22 Memory 23 Processors 230 Speed ​​detection unit 231 Lighting Identification Unit 232 Environmental detection unit 233 Braking judgment section

Claims

1. a speed detection unit that detects a reduction in speed of a forward vehicle based on output information of a sensor that acquires information about the forward vehicle located in front of the vehicle; a light-on identification unit that identifies whether the brake lights of the forward vehicle are on based on an image showing the forward area of ​​the vehicle; a determination unit that determines that the forward vehicle is braking when the light identification unit identifies that the brake lights of the forward vehicle are on, for the forward vehicle in which a speed reduction timing at which the speed detection unit detects a speed reduction and a light illumination timing at which the light identification unit identifies that the brake lights of the forward vehicle are on are synchronized, and having A brake light illumination determination device, characterized in that, when an environment around the vehicle changes, the determination unit re-executes the determination as to whether the speed reduction timing and the illumination timing are synchronized.

2. 2. The brake light illumination determination device according to claim 1, wherein the determination unit determines that the speed reduction timing and the illumination timing are synchronized when a period during which a speed reduction change equal to or greater than a predetermined reference reduction amount is detected coincides with a period during which the brake lights of the forward vehicle are identified as being illuminated.

3. 2. The brake light illumination determination device according to claim 1, wherein, when the forward vehicle is changed to another vehicle, the determination unit executes the determination as to whether the speed reduction timing and the illumination timing are synchronized again.

4. Detecting a reduction in speed of a forward vehicle based on output information of a sensor that acquires information about the forward vehicle located in front of the vehicle; Identifying whether the brake lights of the forward vehicle are on based on an image showing a forward area of ​​the vehicle; When it is identified that the brake lights of the forward vehicle are on, the forward vehicle is determined to be braking when the speed reduction timing at which the reduction in the speed of the forward vehicle is detected and the light-on timing at which the light-on of the brake lights of the forward vehicle are identified are synchronized. and causing the processor to execute the a computer program for determining whether or not the speed reduction timing and the turn-on timing are synchronized when an environment around the vehicle changes;

5. Detecting a reduction in speed of a forward vehicle based on output information of a sensor that acquires information about the forward vehicle located in front of the vehicle; Identifying whether the brake lights of the forward vehicle are on based on an image showing a forward area of ​​the vehicle; When it is identified that the brake lights of the forward vehicle are on, the forward vehicle is determined to be braking when the speed reduction timing at which the reduction in the speed of the forward vehicle is detected and the light-on timing at which the light-on of the brake lights of the forward vehicle are identified are synchronized. This is executed by the brake light illumination determination device, A method for determining whether or not a brake light is turned on, comprising the steps of: when an environment around the vehicle changes, determining again whether or not the speed reduction timing and the turn-on timing are synchronized.

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