Driving Support Devices

Abstract

To provide a driving support device that, even when a traffic light is blocked, can continue supporting the driving of a vehicle for a while.SOLUTION: A driving support device comprises: a traffic light detection unit (detection unit) that repeatedly detects the state of a traffic light ahead of a vehicle and the time of the state; a vehicle control unit (control unit) that, when the traffic light detection unit becomes unable to detect the state of the traffic light, causes the vehicle to continue autonomous driving for at least a predetermined time from the time when the traffic light detection unit detects the state of the traffic light last, based on the color of the last-detected traffic light and the time of the detection; and a control detail notification unit (notification unit) that notifies a driver of the vehicle of the details of control performed by the vehicle control unit.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a driving assistance device. [Background technology]

[0002] 2. Description of the Related Art Recently, driving assistance devices that assist a driver in accelerator operation and steering operation when driving a vehicle have been put into practical use.

[0003] For example, Patent Document 1 discloses a driving assistance device equipped with a function for avoiding a collision with a preceding vehicle. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2022-112350 Summary of the Invention [Problem to be solved by the invention]

[0005] The driving assistance device disclosed in Patent Document 1 operates on the premise that it can recognize both the preceding vehicle and the road environment ahead. However, when a large truck is traveling ahead of the vehicle, the road environment ahead, for example, traffic lights, is blocked, making it impossible to recognize the state of the traffic lights. As a result, there is a possibility that driving assistance cannot be continued.

[0006] An object of the present invention is to provide a driving assistance device that can continue to provide driving assistance for a certain period of time even when a traffic light is blocked. [Means for solving the problem]

[0007] In order to achieve the above object, a driving assistance device according to the present invention includes: a detection unit that repeatedly detects a state of a traffic light ahead of a vehicle; When the vehicle is autonomously driving,When the detection unit is unable to detect the state of the traffic light, at least The time it takes for the traffic light color of the traffic light to change from green to red Allowing the vehicle to continue automatic driving for a predetermined period of time or slowing down said vehicle. The vehicle includes a control unit and a notification unit that notifies a driver of the vehicle of the contents of the control performed by the control unit.

[0008] According to this configuration, even if the traffic light is blocked, driving assistance for the vehicle can be continued for a while, and the driver can be notified of the details. In addition, automatic operation can be continued by regarding the light color as yellow for a predetermined period of time.

[0011] In addition, in the driving assistance device of the present invention, when the last detected light color of the traffic light is blue, the control unit causes the vehicle to continue automatic driving for the specified time from the time when the light color of the traffic light was last detected to be blue.

[0012] With this configuration, automatic driving can be continued as long as the traffic light color can be considered as yellow.

[0013] In the driving assistance device according to the present invention, the control unit decelerates the vehicle after the predetermined time has elapsed.

[0014] According to this configuration, when there is a possibility that the traffic light is red, the vehicle can be decelerated.

[0015] In addition, the driving assistance device of the present invention further includes an estimation unit that estimates the distance from the vehicle to the traffic light, and the control unit causes the vehicle to continue autonomous driving when the light color of the last detected traffic light is blue and it is determined that the vehicle can pass the traffic light before the specified time has elapsed.

[0016] With this configuration, automatic driving can be continued if it is possible to pass through the traffic light.

[0017] In addition, in the driving assistance device of the present invention, the control unit decelerates the vehicle when the light color of the last detected traffic light is blue and it is not determined that the vehicle can pass the traffic light before the specified time has elapsed from the time.

[0018] With this configuration, the vehicle can be slowed down when it is unable to pass through the traffic light.

[0019] In the driving assistance device according to the present invention, the control unit decelerates the vehicle when the color of the light of the traffic signal last detected is other than blue.

[0020] According to this configuration, when there is a possibility that the traffic light is red, the vehicle can be decelerated. Effect of the Invention

[0021] According to the present invention, even if a traffic light is blocked, driving assistance for a vehicle can be continued for a predetermined period of time. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a diagram illustrating a problem with a conventional driving support device. [Diagram 2] FIG. 2 is a diagram illustrating the control content of the driving support device of the first embodiment. [Diagram 3] FIG. 3 is a hardware block diagram illustrating an example of a hardware configuration of the driving assistance device according to the first embodiment. [Figure 4] FIG. 4 is a functional block diagram illustrating an example of a functional configuration of the driving assistance device according to the first embodiment. [Diagram 5] FIG. 5 is a flowchart illustrating an example of a flow of processing performed by the driving assistance device of the first embodiment. [Figure 6] FIG. 6 is a diagram for explaining the control content of the driving support device of the second embodiment. [Figure 7]FIG. 7 is a functional block diagram illustrating an example of a functional configuration of a driving assistance device according to the second embodiment. [Figure 8] FIG. 8 is a flowchart showing an example of the flow of processing performed by the driving assistance device of the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0024] (First embodiment) An outline of the operation of the driving support device of the first embodiment of the present invention will be described with reference to Figures 1 and 2. Figure 1 is a diagram for explaining the problems of the conventional driving support device. Figure 2 is a diagram for explaining the control contents of the driving support device of the first embodiment.

[0025] (Overview of operation of driving support device) A vehicle 1 equipped with a driving assistance device 10 (see FIG. 3) recognizes the road environment on which it is traveling, and if there are no obstacles, it travels at a speed equal to or lower than a set vehicle speed while maintaining a preset distance from a preceding vehicle 2. This type of traveling state is referred to as automatic driving.

[0026] The driving support device 10 detects an obstacle (e.g., a preceding vehicle 2) ahead of the vehicle 1 using a camera 22 installed in front of the vehicle 1 or a distance measuring device such as a lidar or radar installed on the front bumper of the vehicle 1. Then, the driving support device 10 automatically drives the vehicle 1 while maintaining a preset distance between the vehicle and the detected obstacle. The camera 22 also detects a traffic light 3 ahead in the traveling direction and recognizes the light color of the traffic light 3. The driving support device 10 judges whether to continue the automatic driving or to decelerate according to the light color of the recognized traffic light 3.

[0027] If the road ahead of the vehicle 1 is open, the various controls described above are executed, but as shown in Fig. 1, if there is a large preceding vehicle 2 ahead of the vehicle 1, the preceding vehicle 2 may block the visual field 22a of the camera 22. In this state, the camera 22 will not be able to recognize the traffic light 3.

[0028] In order to prevent such obstruction of the traffic light 3, there are some intersections where the traffic light 3 is also installed on the opposite lane. However, it is difficult to install the traffic light 3 on the opposite lane at all intersections. The driving assistance device 10 of this embodiment is designed on the assumption that such obstruction of the traffic light 3 will occur, and even if obstruction of the traffic light 3 occurs, the automatic driving of the vehicle 1 can be continued for a predetermined time T according to the situation before the obstruction.

[0029] 2 shows the contents of the control performed by the driving assistance device 10 of this embodiment when the traffic light 3 is blocked. First, it is assumed that the vehicle 1 detects the traffic light 3 and recognizes its light color at time t=t1 during autonomous driving. Then, it is assumed that a large preceding vehicle 2 then enters in front of the vehicle 1.

[0030] At this time, if the light color detected at time t=t1 is "green," the driving assistance device 10 continues the automatic driving of the vehicle 1. Then, when the time t becomes greater than t1+T, the driving assistance device 10 performs deceleration control of the vehicle 1. The predetermined time T is a preset value, and is set to a value within 2 seconds, for example. Specifically, the predetermined time T is set to a value equivalent to the time from when the traffic light 3 turns off green, through yellow, and until it turns red.

[0031] If the light color detected just before the traffic light 3 is blocked is "green," the light color of the traffic light 3 is considered to remain "green" until at least the predetermined time T has elapsed from that point, so there is no problem with the driving assistance device 10 continuing the current automatic driving. This allows the system to slightly extend the time during which automatic driving is possible for a system that cancels automatic driving when the traffic light 3 can no longer be detected.

[0032] Then, when the predetermined time T has elapsed, the driving support device 10 decelerates the vehicle 1. By decelerating the vehicle 1, the distance between the vehicle 1 and the preceding vehicle 2 increases, and when the camera 22 detects the traffic light 3 again, the driving support device 10 resumes the automatic driving.

[0033] On the other hand, if the light color recognized at time t=t1 is other than "green," i.e., if the light color of the traffic light 3 is "yellow" or "red," the driving support device 10 decelerates the vehicle 1. Then, when the distance between the vehicle 1 and the preceding vehicle 2 increases and the camera 22 detects the traffic light 3 again, the driving support device 10 resumes automatic driving.

[0034] (Hardware configuration of driving assistance device) The hardware configuration of the driving support device 10 will be described with reference to Fig. 3. Fig. 3 is a hardware block diagram showing an example of the hardware configuration of the driving support device of the first embodiment.

[0035] The driving assistance device 10 includes a plurality of ECUs (Electronic Control Units) for controlling each part of the vehicle 1. Each ECU includes a microcontroller unit (microcomputer). The microcomputer includes a CPU, a non-volatile memory such as a flash memory, and a volatile memory such as a dynamic random access memory (DRAM).

[0036] The multiple ECUs include a steering ECU 13, a drive ECU 15, and a braking ECU 17. The steering ECU 13, the drive ECU 15, and the braking ECU 17 are connected via a bus 12 so as to enable communication according to a CAN (Controller Area Network) communication protocol, that is, CAN communication.

[0037] The steering ECU 13 is a control unit that controls the steering device 14 of the vehicle 1. The steering device 14 is, for example, an electric power steering device that applies the torque of an electric motor to a steering mechanism. The steering mechanism includes, for example, a rack-and-pinion steering gear, and is configured such that when a rack shaft moves in the vehicle width direction due to the torque of the electric motor, the left and right steered wheels are turned left and right in accordance with the movement of the rack shaft.

[0038] The drive ECU 15 is a control unit that controls the drive device 16 of the vehicle 1. The drive device 16 may be configured to include an engine as a drive source, a motor as a drive source, or both an engine and a motor as drive sources. The drive device 16 includes a transmission that changes the speed of the drive force from the drive source and outputs it as necessary.

[0039] The brake ECU 17 is a control unit that controls a braking device 18 of the vehicle 1. The braking device 18 may be of a hydraulic type or an electric type. The hydraulic braking device 18 includes a brake actuator, and the function of this brake actuator distributes hydraulic pressure to wheel cylinders of the brakes provided on each wheel, and the hydraulic pressure applies braking force from each brake to the wheels including the driving wheels.

[0040] The aforementioned multiple ECUs include an automatic driving ECU 11, a camera ECU 21, a lidar ECU 23, and the like, as control units for the automatic driving function.

[0041] The automatic driving ECU 11 is the control center of automatic driving control. The automatic driving ECU 11 executes a control program in its own CPU, thereby controlling the driving assistance device 10 in an overall manner. The automatic driving ECU 11 is connected to the steering ECU 13, the drive ECU 15, and the braking ECU 17 so as to be able to communicate via CAN. Specific functions of the automatic driving ECU 11 will be described later (see FIG. 4).

[0042] The autonomous driving ECU 11 is connected to a camera ECU 21, a lidar ECU 23, a GPS receiver 25, a high-precision map database 26, a monitor 27, and a speaker 28 via a bus 20 conforming to the Ethernet (registered trademark) standard, for example.

[0043] The camera ECU 21 is connected to the automatic driving ECU 11 via the bus 20 so as to be able to communicate with the automatic driving ECU 11. The camera ECU 21 is connected to a camera 22. The camera 22 continuously captures still images of a visual field range 22a in front of the vehicle 1 at a predetermined frame rate. The camera ECU 21 receives image signals of still images continuously output from the camera 22. The camera ECU 21 outputs the image signals input from the camera 22 to the automatic driving ECU 11. The automatic driving ECU 11 recognizes the road alignment in front of the vehicle 1, the state of the traffic light 3, and the like by analyzing the image signals acquired from the camera ECU 21. The camera 22 may be a monochrome camera or a color camera. The camera 22 may be a monocular camera or a stereo camera.

[0044] The LIDAR ECU 23 is connected to the automatic driving ECU 11 via the bus 20 so as to be able to communicate with the LIDAR ECU 23. A plurality of LIDARs 24 are connected to the LIDAR ECU 23. The LIDAR 24 irradiates a search range with a laser light, receives reflected light from an object present within the search range with an optical sensor, and outputs a detection signal according to the intensity of the reflected light, i.e., the distance to the object. The LIDARs 24 are disposed, for example, at the left end, center, and right end of the front bumper of the vehicle 1 and the left end, center, and right end of the rear bumper. The LIDAR ECU 23 receives detection signals output from the plurality of LIDARs 24. The LIDAR ECU 23 processes the detection signals acquired from the plurality of LIDARs 24 and transmits data obtained by the processing to the automatic driving ECU 11. Specifically, the LIDAR ECU 23 processes the detection signals input from the plurality of LIDARs 24 to image the position of the object in the direction of each LIDAR 24. The driving assistance device 10 may include a radar ECU and a millimeter-wave radar connected to the radar ECU in addition to the LIDAR ECU 23. Generally, a millimeter-wave radar has a longer distance measurement range than the LIDAR 24, so that short-distance measurement may be performed by the LIDAR 24 and long-distance measurement may be performed by the millimeter-wave radar.

[0045] The GPS receiver 25 is a receiver that receives positioning signals from multiple GPS (Global Positioning System) satellites. The multiple positioning signals received by the GPS receiver 25 are input from the GPS receiver 25 to the automatic driving ECU 11. The automatic driving ECU 11 estimates the current position and traveling direction of the vehicle 1 from the multiple positioning signals. Note that the GPS receiver 25 itself may have a function of estimating the current position and traveling direction of the vehicle 1, and the current position and traveling direction estimated by the GPS receiver 25 may be input to the automatic driving ECU 11.

[0046] The high-precision map database 26 is data including, for example, information on road width and gradient, and information on features such as dividing lines, shoulder lines, intersections, railroad crossings, stop lines, pedestrian crossings, traffic lights, and signs. The autonomous driving ECU 11 verifies the current position of the vehicle 1 estimated based on the positioning signal from the GPS receiver 25 against the contents of the high-precision map database 26, thereby identifying the position of the vehicle 1 on the road. The high-precision map database 26 may be stored in a non-volatile memory built into a microcomputer of the autonomous driving ECU 11, or may be stored in a hard disk drive (HDD) (not shown) connected to the autonomous driving ECU 11.

[0047] The monitor 27 notifies the driver by displaying graphic information and text information related to the operating state of the driving assistance device 10, which is generated by the autonomous driving ECU 11. The monitor 27 is, for example, a liquid crystal monitor or an organic EL monitor.

[0048] The speaker 28 notifies the driver by outputting sounds and voices generated by the autonomous driving ECU 11 and related to the operating state of the driving assistance device 10.

[0049] The driving support device 10 further includes various sensors such as a vehicle speed sensor not shown in Fig. 3. The hardware configuration shown in Fig. 3 is an example, and various modifications are possible to achieve the same functions. Different sensors and actuators may be provided to achieve the same functions.

[0050] (Functional configuration of driving assistance device) The functional configuration of the driving support device 10 will be described with reference to Fig. 4. Fig. 4 is a functional block diagram showing an example of the functional configuration of the driving support device of the first embodiment. Note that the functional block diagram of Fig. 4 shows the minimum configuration required for the automatic driving ECU 11 to realize the contents of the present invention.

[0051] The autonomous driving ECU 11 of the driving assistance device 10 causes its own CPU to execute a control program, thereby realizing as functional units a traffic light detection unit 31, a light color and time storage unit 32, a vehicle control unit 35, and a control content notification unit 36, all of which are shown in Fig. 4. Note that some or all of the functions of the autonomous driving ECU 11 may be realized by dedicated hardware.

[0052] The traffic light detection unit 31 repeatedly detects the state of the traffic light 3 ahead of the vehicle 1 and the time t at that time. The traffic light detection unit 31 is an example of the detection unit in the present invention.

[0053] The traffic light detection unit 31, for example, compares the image captured by the camera 22 with a traffic light recognition model generated by deep learning to detect whether the traffic light 3 is captured in the image, and if the traffic light 3 is captured, at least detects its position and light color. If a color camera is used as the camera 22, the light color can be detected more reliably. The traffic light detection unit 31 may be provided in the camera ECU 21. In that case, the camera ECU 21 outputs to the autonomous driving ECU 11 information indicating whether the traffic light 3 is captured, and if the traffic light 3 is captured, its position and light color.

[0054] The light color and time memory unit 32 stores the light color of the traffic light 3 detected by the traffic light detection unit 31 and the time t at which the traffic light detection unit 31 detected the traffic light 3. The time t is measured by a timer included in a CPU of the autonomous driving ECU 11.

[0055] When the traffic light detection unit 31 is no longer able to detect the state of the traffic light 3, the vehicle control unit 35 causes the vehicle 1 to continue autonomous driving for at least a predetermined time T from time t1 based on the last detected state of the traffic light 3, i.e., the light color, and the time t1 at that time. The predetermined time T is set to, for example, the time it takes for the light color of the traffic light 3 to transition from an unlit green to a lit red. The vehicle control unit 35 is an example of a control unit in the present invention.

[0056] Specifically, when the light color of the traffic light 3 that was last detected was blue, the vehicle control unit 35 causes the vehicle 1 to continue autonomous driving for a predetermined time T from the time t1 when the light color of the traffic light 3 was last detected as blue.

[0057] Furthermore, the vehicle control unit 35 decelerates the vehicle 1 after a predetermined time T has elapsed from time t1.

[0058] The control content notification unit 36 ​​notifies the driver of the vehicle 1 of the content of the control performed by the vehicle control unit 35. Specifically, the control content notification unit 36 ​​notifies the driver of the control content by displaying the control content performed by the vehicle 1 on the monitor 27. The control content notification unit 36 ​​also notifies the driver of the control content by outputting the control content performed by the vehicle 1 as audio from the speaker 28. The control content notification unit 36 ​​is an example of a notification unit in the present invention.

[0059] (Processing flow performed by the driving assistance device) The flow of processing performed by the driving support device 10 will be described with reference to Fig. 5. Fig. 5 is a flowchart showing an example of the flow of processing performed by the driving support device of the first embodiment.

[0060] The vehicle control unit 35 starts the automatic driving of the vehicle 1 (step S11).

[0061] The traffic light detection unit 31 determines whether the traffic light 3 has been detected (step S12). If it is determined that the traffic light 3 has been detected (step S12: Yes), the process proceeds to step S13. On the other hand, if it is determined that the traffic light 3 has not been detected (step S12: No), step S12 is repeated.

[0062] When it is determined in step S12 that a traffic light 3 has been detected, the light color and time storage unit 32 stores the time t and the light color of the traffic light 3 at that time (step S13).

[0063] Thereafter, the traffic light detection unit 31 determines whether the traffic light 3 cannot be detected (step S14). If it is determined that the traffic light 3 cannot be detected (step S14: Yes), the process proceeds to step S15. On the other hand, if it is not determined that the traffic light 3 cannot be detected (step S14: No), that is, if it is determined that the traffic light 3 can be detected, the process returns to step S13.

[0064] If it is determined in step S14 that the traffic light 3 cannot be detected, the light color and time storage unit 32 determines whether the last stored light color of the traffic light 3 is green (step S15). If it is determined that the last stored light color of the traffic light 3 is green (step S15: Yes), the process proceeds to step S16. On the other hand, if it is not determined that the last stored light color of the traffic light 3 is green (step S15: No), the process proceeds to step S20.

[0065] If it is determined in step S15 that the last stored light color of the traffic light 3 is green, the vehicle control unit 35 determines whether the current time is within a predetermined time T from the time t last detected by the traffic light detection unit 31 (step S16). If it is determined that it is within the predetermined time T (step S16: Yes), the process proceeds to step S17. On the other hand, if it is not determined that it is within the predetermined time T (step S16: No), the process proceeds to step S20.

[0066] If it is determined in step S16 that the time is within the predetermined time T, the vehicle control unit 35 causes the vehicle 1 to continue the automatic driving (step S17).

[0067] The control content notifying unit 36 ​​notifies the driver of the vehicle 1 that the autonomous driving will continue (step S18).

[0068] The vehicle control unit 35 determines whether the current time is within a predetermined time T from the time t last detected by the traffic light detection unit 31 (step S19). If it is determined that the current time is within the predetermined time T (step S19: Yes), the process returns to step S14. On the other hand, if it is not determined that the current time is within the predetermined time T (step S19: No), the process proceeds to step S20.

[0069] If it is not determined in step S19 that the time is within the predetermined time T, that is, if it is determined that the predetermined time T or more has passed since time t, the vehicle control unit 35 performs deceleration control of the vehicle 1 (step S20). Note that if it is not determined in step S15 that the last stored light color of the traffic light 3 is green, and if it is not determined in step S16 that the time is within the predetermined time T, that is, if it is determined that the predetermined time T or more has passed since time t, the vehicle control unit 35 also performs deceleration control of the vehicle 1.

[0070] The control content notification unit 36 ​​notifies the driver of the vehicle 1 that the vehicle 1 will decelerate (step S21). After that, the driving assistance device 10 ends the process of FIG.

[0071] Although not shown in Figure 5, in step S20, when vehicle 1 decelerates, if the distance between vehicle 1 and the preceding vehicle 2 increases and traffic light 3 becomes detectable again, vehicle control unit 35 may continue automatic driving according to the light color of traffic light 3 detected at that time.

[0072] Here, the control contents performed by the driving support device 10 on the vehicle 1 performing automatic driving have been described, but the driving support device 10 may perform the same control contents when the driver is driving the vehicle 1 by himself. Specifically, when the vehicle 1 is being manually driven, the vehicle control unit 35 may not intervene in the driving until a predetermined time T has elapsed from the time when it was last detected that the light color of the traffic light 3 was green, and may decelerate the vehicle 1 and notify the driver at the timing when the predetermined time T has elapsed. Also, when the light color of the traffic light 3 last detected is other than green, the vehicle control unit 35 may decelerate the vehicle 1 and notify the driver.

[0073] (Effects of the first embodiment) As described above, the driving assistance device 10 of the first embodiment includes a traffic light detection unit 31 (detection unit) that repeatedly detects the state of the traffic light 3 ahead of the vehicle 1 and the time t at that time, a vehicle control unit 35 (control unit) that, when the traffic light detection unit 31 is no longer able to detect the state of the traffic light 3, causes the vehicle 1 to continue automatic driving for at least a predetermined time T from the time t based on the light color of the traffic light 3 last detected and the time t at that time, and a control content notification unit 36 ​​(notification unit) that notifies the driver of the vehicle 1 of the content of the control performed by the vehicle control unit 35. Therefore, even if the traffic light 3 is blocked, the driving assistance of the vehicle 1 can be continued for a while, and the driver can be notified of the content.

[0074] In the driving assistance device 10 of the first embodiment, the predetermined time T is the time it takes for the light color of the traffic light 3 to change from green to red. Therefore, during the predetermined time T, the light color is considered to be yellow, so that the automatic driving can be continued.

[0075] Furthermore, in the driving assistance device 10 of the first embodiment, when the light color of the traffic light 3 last detected is green, the vehicle control unit 35 (control unit) causes the vehicle 1 to continue autonomous driving for a predetermined time T from the time when the light color of the traffic light 3 was last detected as green. Therefore, autonomous driving can be continued as long as the light color of the traffic light 3 can be considered as yellow.

[0076] Furthermore, in the driving assistance device 10 of the first embodiment, the vehicle control unit 35 (control unit) decelerates the vehicle 1 after a predetermined time T has elapsed. Therefore, when there is a possibility that the light color of the traffic light 3 is red, the vehicle 1 can be decelerated.

[0077] Furthermore, in the driving assistance device 10 of the first embodiment, the vehicle control unit 35 (control unit) decelerates the vehicle 1 when the light color of the last detected traffic light 3 is other than blue. Therefore, when there is a possibility that the light color of the traffic light 3 is red, the vehicle 1 can be decelerated.

[0078] Second embodiment A driving support device 10a according to a second embodiment of the present invention will be described below with reference to the drawings. The driving support device 10a is a device in which, compared to the driving support device 10 described in the first embodiment, a function for estimating a distance D from the vehicle 1 to the traffic light 3 and a function for determining whether the vehicle 1 can pass the traffic light 3 based on the light color of the traffic light 3 when the vehicle 1 last detected the traffic light 3 and the distance D to the traffic light 3 estimated at that time are added.

[0079] (Overview of operation of driving support device) An outline of the operation of the driving support device 10a will be described with reference to Fig. 6. Fig. 6 is a diagram illustrating the control content of the driving support device of the second embodiment.

[0080] Assume that a vehicle 1, during autonomous driving, detects a traffic light 3 at time t=t1 and recognizes the color of its lights. Then, assume that a large preceding vehicle 2 then enters in front of the vehicle 1.

[0081] At this time, if the light color recognized at time t=t1 is "green," the driving assistance device 10a continues the automatic driving of the vehicle 1. Furthermore, the driving assistance device 10a estimates the distance D from the vehicle 1 to the traffic light 3. Then, the driving assistance device 10a judges whether it is possible to pass the traffic light 3 within a predetermined time T while maintaining the current vehicle speed. If it is judged that it is possible to pass the traffic light 3 within the predetermined time T, the driving assistance device 10a continues the automatic driving. Note that the driving assistance device 10a judges whether it is possible to pass the traffic light 3 within the predetermined time T depending on whether the vehicle 1 can travel the distance D within the predetermined time T while maintaining the current vehicle speed.

[0082] On the other hand, if the light color recognized at time t=t1 is "green" and it is determined that the vehicle 1 cannot pass the traffic light 3 within the predetermined time T, the driving assistance device 10a decelerates the vehicle 1.

[0083] Furthermore, if the light color recognized at time t=t1 is other than "green", that is, if the light color of the traffic light 3 is "yellow" or "red", the driving assistance device 10a decelerates the vehicle 1.

[0084] When the vehicle 1 decelerates, the distance between the vehicle 1 and the preceding vehicle 2 increases, and the camera 22 detects the traffic light 3 again, the driving assistance device 10a resumes the automatic driving.

[0085] Although the behavior of the preceding vehicle 2 is not taken into consideration here, the behavior of the preceding vehicle 2 may be further taken into consideration to determine whether it is possible to pass the traffic light 3 within the predetermined time T.

[0086] (Hardware configuration of driving assistance device) The hardware configuration of the driving assistance device 10a is the same as that of the driving assistance device 10 (see FIG. 3), and therefore will not be described. The names and symbols indicating the hardware components of the driving assistance device 10a will be described using the names and symbols indicating the hardware components of the driving assistance device 10.

[0087] (Functional configuration of driving assistance device) The functional configuration of the driving support device 10a will be described with reference to Fig. 7. Fig. 7 is a functional block diagram showing an example of the functional configuration of the driving support device of the second embodiment. Note that the functional block diagram shown in Fig. 7 shows the minimum configuration required for the automatic driving ECU 11 to realize the contents of the present invention.

[0088] The autonomous driving ECU 11 of the driving assistance device 10a causes its own CPU to execute a control program to realize, as functional units, a traffic light detection unit 31, a light color and time storage unit 32, a distance estimation unit 33, a passage permission / prohibition determination unit 34, a vehicle control unit 35a, and a control content notification unit 36, all of which are shown in Fig. 7. Note that some or all of the functions of the autonomous driving ECU 11 may be realized by dedicated hardware.

[0089] The traffic light detection unit 31, the light color and time storage unit 32, and the control content notification unit 36 ​​have the same functions as those of the driving assistance device 10 described in the first embodiment, and therefore will not be described again.

[0090] The distance estimation unit 33 estimates a distance D from the vehicle 1 to the traffic light 3. The distance estimation unit 33 is an example of the estimation unit in the present invention.

[0091] There is no restriction on the method by which the distance estimation unit 33 estimates the distance D. For example, if the installation position of the traffic light 3 is stored in the high precision map database 26, the distance D may be estimated based on the current position of the vehicle 1 measured based on the positioning signal of the GPS receiver 25 and the installation position of the traffic light 3. In addition, since the size of the traffic light 3 is known, the distance D may be estimated based on the apparent size of the traffic light 3 detected by the traffic light detection unit 31 and the actual size of the traffic light 3.

[0092] The passing possibility determination unit 34 determines whether the vehicle 1 can pass the traffic light 3 located a distance D ahead within a predetermined time T while proceeding at the current vehicle speed v.

[0093] The vehicle control unit 35a causes the vehicle 1 to continue automatic driving when the light color of the last detected traffic light 3 is green and it is determined that the vehicle 1 can pass the traffic light 3 before a predetermined time T has elapsed. The vehicle control unit 35a also decelerates the vehicle 1 when the light color of the last detected traffic light 3 is green and it is not determined that the vehicle 1 can pass the traffic light 3 before a predetermined time T has elapsed from the time when the vehicle 1 last detected the traffic light 3. Furthermore, the vehicle control unit 35a also decelerates the vehicle 1 when the light color of the last detected traffic light 3 is other than blue. The vehicle control unit 35a is an example of a control unit in the present invention.

[0094] (Processing flow performed by the driving assistance device) The flow of processing performed by the driving support device 10a will be described with reference to Fig. 8. Fig. 8 is a flowchart showing an example of the flow of processing performed by the driving support device of the second embodiment.

[0095] The vehicle control unit 35a starts the automatic driving of the vehicle 1 (step S31).

[0096] The traffic light detection unit 31 determines whether or not the traffic light 3 has been detected (step S32). If it is determined that the traffic light 3 has been detected (step S32: Yes), the process proceeds to step S33. On the other hand, if it is determined that the traffic light 3 has not been detected (step S32: No), step S32 is repeated.

[0097] When it is determined in step S32 that a traffic light 3 has been detected, the light color and time storage unit 32 stores the time t and the light color of the traffic light 3 at that time (step S33).

[0098] The distance estimation unit 33 estimates the distance D from the vehicle 1 to the traffic light 3 (step S34).

[0099] Thereafter, the traffic light detection unit 31 determines whether the traffic light 3 cannot be detected (step S35). If it is determined that the traffic light 3 cannot be detected (step S35: Yes), the process proceeds to step S36. On the other hand, if it is not determined that the traffic light 3 cannot be detected (step S35: No), that is, if it is determined that the traffic light 3 can be detected, the process returns to step S33.

[0100] If it is determined in step S35 that the traffic light 3 cannot be detected, the light color and time storage unit 32 determines whether the last stored light color of the traffic light 3 was green (step S36). If it is determined that the last stored light color of the traffic light 3 was green (step S36: Yes), the process proceeds to step S37. On the other hand, if it is not determined that the last stored light color of the traffic light 3 was green (step S36: No), the process proceeds to step S41.

[0101] If it is determined in step S36 that the last stored light color of the traffic light 3 was green, the passing possibility determination unit 34 determines whether it is possible to pass through the traffic light 3 within a predetermined time T from the time t last detected by the traffic light detection unit 31 (step S37). If it is determined that it is possible to pass through the traffic light 3 within the predetermined time T (step S37: Yes), the process proceeds to step S38. On the other hand, if it is not determined that it is possible to pass through the traffic light 3 within the predetermined time T (step S37: No), the process proceeds to step S41.

[0102] If it is determined in step S37 that the vehicle 1 can pass the traffic light 3 within the predetermined time T, the vehicle control unit 35a causes the vehicle 1 to continue the automatic driving (step S38).

[0103] The control content notification unit 36 ​​notifies the driver of the vehicle 1 that the autonomous driving will continue (step S39).

[0104] The vehicle control unit 35a determines whether the current time is within a predetermined time T from the time t last detected by the traffic light detection unit 31 (step S40). If it is determined that the current time is within the predetermined time T (step S40: Yes), the process returns to step S35. On the other hand, if it is not determined that the current time is within the predetermined time T (step S40: No), the process proceeds to step S41.

[0105] If it is not determined in step S40 that the time is within the predetermined time T, that is, if it is determined that the predetermined time T or more has elapsed since time t, the vehicle control unit 35a performs deceleration control of the vehicle 1 (step S41). Note that if it is not determined in step S36 that the last stored light color of the traffic light 3 is green, and if it is not determined in step S37 that the vehicle can pass through the traffic light 3 within the predetermined time T, the vehicle control unit 35a also performs deceleration control of the vehicle 1 in step S41.

[0106] The control content notification unit 36 ​​notifies the driver of the vehicle 1 that the vehicle 1 will decelerate (step S42). After that, the driving assistance device 10a ends the process of FIG.

[0107] Although not shown in Figure 8, in step S41, when vehicle 1 decelerates, if the distance between vehicle 1 and the preceding vehicle 2 increases and traffic light 3 becomes detectable again, vehicle control unit 35a may continue automatic driving according to the light color of traffic light 3 detected at that time.

[0108] Although the control contents performed by the driving support device 10 on the vehicle 1 performing automatic driving have been described here, the driving support device 10 may perform the same control contents on the vehicle 1 not performing automatic driving. That is, the driving support device 10 may activate the automatic brake of the vehicle 1 when it is determined that deceleration control is required.

[0109] (Effects of the second embodiment) As described above, the driving assistance device 10a of the second embodiment further includes a distance estimation unit 33 (estimation unit) that estimates the distance D from the vehicle 1 to the traffic light 3, and the vehicle control unit 35a (control unit) causes the vehicle 1 to continue automatic driving when the light color of the last detected traffic light 3 is green and it is determined that the vehicle 1 can pass the traffic light 3 before the predetermined time T has elapsed. Therefore, automatic driving can be continued when the vehicle 1 can pass the traffic light 3.

[0110] Furthermore, in the driving assistance device 10a of the second embodiment, the vehicle control unit 35a (control unit) decelerates the vehicle 1 when the light color of the last detected traffic light 3 is green and it is not determined that the vehicle 1 can pass the traffic light 3 before a predetermined time T has elapsed since the time the vehicle 1 last detected the traffic light 3. Therefore, the vehicle 1 can be decelerated when it cannot pass the traffic light 3.

[0111] Although the embodiment of the present invention has been described above, the above-mentioned embodiment is presented as an example and is not intended to limit the scope of the present invention. This new embodiment can be embodied in various other forms. In addition, various omissions, substitutions, and modifications can be made without departing from the gist of the invention. In addition, this embodiment is included in the scope and gist of the invention, and is included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0112] 1 vehicle 2 Leading vehicle 3. Traffic lights 10,10a Driving support device 11 Autonomous Driving ECU 22 Camera 31 Traffic light detector (detector) 32 Light color and time memory section 33 Distance estimation section (estimation section) 34 Passability judgment unit 35, 35a Vehicle control unit (control unit) 36 Control content notification unit (notification unit) D Distance T predetermined time

Claims

1. a detection unit that repeatedly detects the state of a traffic light ahead of the vehicle and the time at that time; a control unit that, when the detection unit is unable to detect the state of the traffic light while the vehicle is performing autonomous driving, causes the vehicle to continue autonomous driving for at least a predetermined time from the time until the traffic light color of the traffic light changes from an unlit green to a lit red, based on the last detected light color of the traffic light and the time at that time, or causes the vehicle to decelerate; A notification unit that notifies the driver of the vehicle of the contents of the control performed by the control unit. Driving assistance device.

2. When the last detected light color of the traffic light is green, the control unit causes the vehicle to continue automatic driving for the predetermined time from the time when the last detected light color of the traffic light is green. The driving assistance device according to claim 1 .

3. The control unit decelerates the vehicle after the predetermined time has elapsed. The driving assistance device according to claim 1 or 2.

4. Further comprising an estimation unit that estimates a distance from the vehicle to the traffic light, the control unit causes the vehicle to continue automatic driving when it is determined that the light color of the last detected traffic light is green and the vehicle can pass the traffic light before the predetermined time has elapsed from the time when the traffic light was last detected. The driving assistance device according to claim 1 .

5. The control unit decelerates the vehicle when the light color of the last detected traffic light is green and it is not determined that the vehicle can pass through the traffic light before the predetermined time has elapsed from the time. The driving assistance device according to claim 4.

6. The control unit decelerates the vehicle when the light color of the last detected traffic light is other than blue. The driving assistance device according to claim 1 or 4.

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