Driving assistance devices

Abstract

To provide a driving support device that can start detecting obstacles in a range related to a traveling direction of a vehicle before passing through an intersection with a traffic light.SOLUTION: A driving support device includes: a traffic light detection unit that repeatedly detects a traffic light in front of a vehicle, a light color of the traffic light, and a distance to the traffic light; a traveling direction specifying unit that specifies a traveling direction of the vehicle at the traffic light; an obstacle detection range setting unit (setting unit) that sets a detection range of an obstacle at an intersection with the traffic signal according to the light color of the traffic signal and the traveling direction of the vehicle at the traffic signal; an obstacle detection unit that detects an obstacle existing in the detection range set by the obstacle detection range setting unit: and a vehicle control unit (control unit) that controls a traveling state of the vehicle based on a road linearity of the intersection, the light color of the traffic signal, and a state of the obstacle detected by the obstacle detection unit, in front of where the vehicle enters the intersection.SELECTED DRAWING: Figure 6

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 that recognizes the surrounding environment in the direction in which the vehicle is traveling and controls the driving of the vehicle. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-189883 Summary of the Invention [Problem to be solved by the invention]

[0005] The driving assistance device disclosed in Patent Document 1 determines whether the vehicle has passed through an intersection by detecting the color of the traffic lights, and then detects obstacles in the vehicle's direction of travel after the vehicle enters the intersection. Therefore, there is a risk that the vehicle will suddenly decelerate if an obstacle in the vehicle's direction of travel is detected after the vehicle enters the intersection.

[0006] An object of the present invention is to provide a driving assistance device that can start detecting obstacles in a range related to the vehicle's traveling direction before the vehicle passes through an intersection with traffic lights. [Means for solving the problem]

[0007] In order to achieve the above object, a driving assistance device according to the present invention includes a traffic light detection unit that repeatedly detects a traffic light at an intersection ahead of a vehicle, the light color of the traffic light, and the distance to the traffic light; a traveling direction identification unit that identifies the traveling direction of the vehicle at the intersection with traffic lights; and an obstacle detection unit that, depending on the light color of the traffic light and the traveling direction of the vehicle at the intersection with traffic lights, identifies an obstacle within the detection range of an obstacle detection sensor provided in the vehicle in the traveling direction of the vehicle at the intersection with traffic lights and in a direction intersecting the traveling direction. , limited a setting unit that sets a predetermined detection range; an obstacle detection unit that starts detecting obstacles that exist within the detection range set by the setting unit when the vehicle reaches a point a predetermined distance before the intersection where the traffic lights are located; and a control unit that controls the driving state of the vehicle based on the road alignment at the intersection, the light color of the traffic lights, and the state of the obstacle detected by the obstacle detection unit, from just before the vehicle enters the intersection.

[0008] With this configuration, obstacles can be detected within a range related to the vehicle's direction of travel before the vehicle passes through an intersection with traffic lights, making it possible to predict the state of obstacles in the vehicle's direction of travel. This prevents delays in obstacle detection when passing through an intersection. Furthermore, the ability to limit the obstacle detection range reduces the calculation load.

[0009] In addition, in the driving assistance device according to the present invention, When the vehicle turns left at the intersection with a traffic light, the setting unit further sets an obstacle detection range in a right-turn lane of an oncoming traffic lane according to the light color of the traffic light.

[0010] According to this configuration, When a vehicle is about to turn left, it is possible to detect a vehicle waiting to turn right in the oncoming lane.

[0011] In the driving assistance device according to the present invention, the control unit at least determines whether to stop or pass the vehicle at the intersection, and controls the traveling direction and speed of the vehicle.

[0012] This configuration allows smooth control of the vehicle at the intersection. [Effects of the Invention]

[0013] According to the present invention, it is possible to start detecting obstacles in a range related to the traveling direction of the vehicle before the vehicle passes through an intersection with traffic lights. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram illustrating the operation of a driving assistance device according to an embodiment when going straight through an intersection. [Figure 2] FIG. 2 is a diagram illustrating the operation of the driving support device of the embodiment when turning right at an intersection. [Figure 3] FIG. 3 is a diagram illustrating the operation of the driving support device of the embodiment when turning left at an intersection. [Figure 4] FIG. 4 is a diagram illustrating a method for identifying the position of the obstacle detection range. [Figure 5] FIG. 5 is a hardware block diagram illustrating an example of a hardware configuration of the driving assistance device according to the embodiment. [Figure 6] FIG. 6 is a functional block diagram illustrating an example of a functional configuration of the driving assistance device according to the embodiment. [Figure 7] FIG. 7 is a flowchart illustrating an example of a flow of processing performed by the driving assistance device according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0016] First, an outline of the operation of a driving support device according to an embodiment of the present invention will be described with reference to Fig. 1 to Fig. 3. Fig. 1 is a diagram illustrating the operation of the driving support device according to the embodiment when going straight through an intersection. Fig. 2 is a diagram illustrating the operation of the driving support device according to the embodiment when turning right at an intersection. Fig. 3 is a diagram illustrating the operation of the driving support device according to the embodiment when turning left at an intersection.

[0017] (Overview of operation of driving assistance device) The vehicle 1 equipped with the driving assistance device 8 of this embodiment recognizes the road environment on which it is traveling, and if there are no obstacles, it travels at a speed equal to or less than a set vehicle speed while maintaining a preset inter-vehicle distance from the preceding vehicle 6. Furthermore, if the driving assistance device 8 detects an obstacle in the traveling direction of the vehicle 1, it slows down, stops the vehicle 1, or performs obstacle avoidance to avoid a collision with the obstacle. Traveling in this manner with the driving assistance device 8 operating is referred to as autonomous driving.

[0018] That is, the driving support device 8 performs accelerator operation, brake operation, and steering operation of the vehicle 1 in place of the driver depending on the driving environment.

[0019] In particular, the driving assistance device 8 of this embodiment reads ahead the road environment in accordance with the route of the vehicle 1.

[0020] FIG. 1 shows a situation in which a vehicle 1 equipped with a driving support device 8 travels straight ahead through an intersection 2 ahead.

[0021] At intersection 2, two roads with one lane on each side intersect at a right angle. A stop line 5 is drawn on the driving lane of each road at the entrance to intersection 2. In addition, traffic lights 3a, 3b, 3c, and 3d are installed on each road, for example, on the far side of intersection 2. Furthermore, crosswalks 4a, 4b, 4c, and 4d are drawn on each road on the near side of intersection 2.

[0022] A vehicle 1 equipped with a driving assistance device 8 is traveling with a driving destination set in advance by a car navigation system, etc. Therefore, the driving assistance device 8 operates in a state where it knows in advance the traveling direction (arrow A in FIG. 1) at an intersection 2 ahead.

[0023] The driving assistance device 8 drives the vehicle 1 while detecting the state of obstacles around the vehicle 1. Obstacles range from cars traveling on the road, cars parked on the road, bicycles, motorcycles, pedestrians, fallen objects on the road, and many other things.

[0024] It is desirable for the driving assistance device 8 to detect obstacles all around the vehicle 1, but in order to reduce the calculation load when detecting obstacles as much as possible, obstacle detection is performed only within a necessary and sufficient range depending on the direction in which the vehicle 1 is traveling.

[0025] For example, when it is known that the vehicle 1 will go straight through the intersection 2, the driving assistance device 8 detects obstacles within detection ranges 10a, 10b, 10c, 10d, 10e, and 10f shown in Fig. 1. Detection ranges 10a, 10b, 10c, 10d, 10e, and 10f indicate the ranges within which obstacles exist that may affect the driving of the vehicle 1 going straight through the intersection 2.

[0026] The detection range 10a is a forward area including the lane in which the vehicle 1 is traveling. For example, a leading vehicle 6 may be present in the detection range 10a.

[0027] The detection range 10b is an area that includes the crosswalk 4a just before the intersection 2. In the detection range 10b, there is a possibility that pedestrians who are currently crossing the crosswalk 4a or who are about to start crossing the crosswalk 4a may be present.

[0028] The detection range 10c is an area that includes the crosswalk 4b at the back of the intersection 2. In the detection range 10c, there is a possibility that pedestrians who are currently crossing the crosswalk 4b or who are about to start crossing the crosswalk 4b may be present.

[0029] The detection range 10d is an area including the driving lane on the right side of the vehicle 1 at the intersection 2. Cars, bicycles, motorcycles, etc. may be present in the detection range 10d.

[0030] The detection range 10e is an area including the driving lane on the left side of the vehicle 1 at the intersection 2. Cars, bicycles, motorcycles, etc. may be present in the detection range 10e.

[0031] The detection range 10f is an area where there is a possibility that a vehicle waiting to turn right may be present in the oncoming lane relative to the lane in which the vehicle 1 is traveling at the intersection 2. In the detection range 10f, there is a possibility that a car, a motorcycle, etc. waiting to turn right may be present.

[0032] The method by which the driving assistance device 8 identifies the position of each detection range will be described later (see FIG. 4).

[0033] Furthermore, when it is known that the vehicle 1 will turn right at the intersection 2, the driving assistance device 8 detects obstacles within detection ranges 10a, 10b, 10d, 10e, 10g, and 10h shown in Fig. 2. Detection ranges 10a, 10b, 10d, 10e, 10g, and 10h indicate the ranges within which obstacles exist that may affect the driving of the vehicle 1 turning right at the intersection 2.

[0034] The detection ranges 10a, 10b, 10d, and 10e are as described in FIG.

[0035] The detection range 10g is an area including the oncoming lane relative to the driving lane of the vehicle 1, on the far side of the intersection 2. Cars, bicycles, motorcycles, etc. entering the intersection 2 may be present in the detection range 10g.

[0036] The detection range 10h is an area that includes the crosswalk 4d. In the detection range 10h, there is a possibility that pedestrians who are currently crossing the crosswalk 4d or who are about to start crossing the crosswalk 4d may be present.

[0037] Furthermore, when it is known that the vehicle 1 will turn left at the intersection 2, the driving assistance device 8 detects obstacles within detection ranges 10a, 10b, 10d, 10f, and 10i shown in Fig. 3. The detection ranges 10a, 10b, 10d, 10f, and 10i indicate the ranges within which obstacles exist that may affect the driving of the vehicle 1 turning left at the intersection 2.

[0038] The detection ranges 10a, 10b, 10d, and 10f are as described in FIG.

[0039] The detection range 10i is an area that includes the crosswalk 4c. In the detection range 10i, there is a possibility that a pedestrian who is crossing the crosswalk 4h or a pedestrian who is about to start crossing the crosswalk 4c may be present.

[0040] 1 to 3, the regions indicating the respective detection ranges are expressed as ellipses, but are not limited to ellipses. That is, the regions indicating the respective detection ranges may be expressed as rectangles, for example.

[0041] Furthermore, although Figures 1 to 3 show the case where the intersection 2 has the shape of a crossroad, the driving assistance device 8 similarly has information indicating the obstacle detection range according to the direction of travel of the vehicle 1 for intersections 2 of other shapes.

[0042] (Method of determining the location of an obstacle in the detection range) A method by which the driving assistance device 8 specifies the position of each of the above-mentioned detection ranges will be described with reference to Fig. 4. Fig. 4 is a diagram illustrating a method for specifying the position of an obstacle detection range.

[0043] The driving assistance device 8 uses a camera 22, a lidar 24, a GPS receiver 25, a high-precision map database 26 (see FIG. 5), etc., which will be described later, to identify the position of an obstacle around the vehicle 1. The position of an obstacle can be identified, for example, by the distance from the vehicle 1 and the deviation angle with respect to the traveling direction of the vehicle 1.

[0044] FIG. 4 is a diagram for explaining a method of specifying the position of the detection range 10d described in FIG. 1 by way of example.

[0045] It is assumed that the position of the detection range 10d is stored in advance in the high-precision map database 26.

[0046] The current position of the vehicle 1 is detected at any time, for example, by GPS positioning.

[0047] The driving support device 8 calculates the relative positional relationship between the detected current position of the vehicle 1 and the detection range 10d at the intersection 2 ahead. As a result, as shown in FIG. 4, the detection range 10d is in the range from the distance Da to the distance Db in the traveling direction of the vehicle 1, and the deviation angle with respect to the traveling direction of the vehicle 1 is in the range from the deviation angle θa to the deviation angle θb.

[0048] Then, the driving support device 8 selectively detects only the obstacles within the range. More specifically, when the distance D from the vehicle 1 of the obstacle detected by the driving support device 8 satisfies Da < D < Db and the deviation angle θ from the traveling direction of the vehicle 1 satisfies θa < θ < θb, it is determined that the detected obstacle exists within the detection range 10d.

[0049] Each time the current position of the vehicle 1 is updated, the driving support device 8 performs the above-described process to continuously specify the position of the detection range 10d that changes with time.

[0050] (Hardware Configuration of Driving Support Device) The hardware configuration of the driving support device 8 will be described using FIG. 5. FIG. 5 is a hardware block diagram showing an example of the hardware configuration of the driving support device of the embodiment.

[0051] The driving assistance device 8 includes a plurality of ECUs (Electronic Control Units) for controlling various parts of the vehicle 1. Each ECU includes a microcontroller unit (microcomputer). The microcomputer includes a CPU, a nonvolatile memory such as a flash memory, and a volatile memory such as a DRAM (Dynamic Random Access Memory).

[0052] 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 be able to communicate according to a CAN (Controller Area Network) communication protocol, that is, to communicate using CAN.

[0053] 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 torque from an electric motor to a steering mechanism. The steering mechanism includes, for example, a rack-and-pinion steering gear, and is configured so 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 turn left and right in accordance with the movement of the rack shaft.

[0054] The drive ECU 15 is a control unit that controls the drive unit 16 of the vehicle 1. The drive unit 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 unit 16 includes a transmission that changes the speed of the drive force from the drive source and outputs it as necessary.

[0055] The brake ECU 17 is a control unit that controls the braking device 18 of the vehicle 1. The braking device 18 may be hydraulic or electric. 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 causes each brake to apply braking force to the wheels, including the drive wheels.

[0056] The aforementioned plurality of ECUs also 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.

[0057] The autonomous driving ECU 11 is the control center for autonomous driving control. The autonomous driving ECU 11 executes a control program in its own CPU to comprehensively control the driving assistance device 8. The autonomous driving ECU 11 is connected to the steering ECU 13, drive ECU 15, and braking ECU 17 so as to be able to communicate via CAN. Specific functions of the autonomous driving ECU 11 will be described later (see FIG. 6).

[0058] 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.

[0059] The camera ECU 21 is communicatively connected to the autonomous driving ECU 11 via the bus 20. A camera 22 is connected to the camera ECU 21. The camera 22 continuously captures still images of a field of view 22a ahead of the vehicle 1 at a predetermined frame rate. Image signals of the still images continuously output from the camera 22 are input to the camera ECU 21. The camera ECU 21 outputs the image signals input from the camera 22 to the autonomous driving ECU 11. The autonomous driving ECU 11 then analyzes the image signals acquired from the camera ECU 21 to recognize the road alignment ahead of the vehicle 1, the state of the traffic lights 3, obstacles, etc. Note that the camera 22 may be a monochrome camera or a color camera. The camera 22 may also be a monocular camera or a stereo camera.

[0060] The LIDAR ECU 23 is communicatively connected to the autonomous driving ECU 11 via the bus 20. A plurality of LIDARs 24 are connected to the LIDAR ECU 23. Each LIDAR 24 irradiates a search range with laser light, receives reflected light from objects within the search range using an optical sensor, and outputs a detection signal corresponding to the intensity of the reflected light, i.e., the distance to the object. The LIDARs 24 are, for example, disposed at the left, center, and right ends of the front bumper and the left, center, and right ends of the rear bumper of the vehicle 1. The LIDAR ECU 23 receives detection signals output from the plurality of LIDARs 24. The LIDAR ECU 23 processes the detection signals received from the plurality of LIDARs 24 and transmits the data obtained by the processing to the autonomous driving ECU 11. Specifically, the LIDAR ECU 23 processes the detection signals received from the plurality of LIDARs 24 to generate an image of the location of an object in the direction of each LIDAR 24. The driving assistance device 8 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 capability than the LIDAR 24, so that the LIDAR 24 may be used to measure short distances and the millimeter-wave radar may be used to measure long distances.

[0061] 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 autonomous driving ECU 11. The autonomous 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 for 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 autonomous driving ECU 11. Note that instead of the GPS receiver 25, a GNSS (Global Navigation Satellite System) receiver having similar functions may be provided.

[0062] The high-precision map database 26 is data including, for example, information on road width and gradient, and information on features such as lane markings, 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 in the autonomous driving ECU 11, or may be stored in a hard disk drive (HDD) (not shown) connected to the autonomous driving ECU 11.

[0063] The monitor 27 notifies the driver by displaying graphic information and text information generated by the autonomous driving ECU 11 and relating to the operating state of the driving assistance device 8. The monitor 27 is, for example, a liquid crystal monitor or an organic EL monitor.

[0064] The speaker 28 notifies the driver by outputting sounds or voices generated by the autonomous driving ECU 11 and related to the operating state of the driving assistance device 8. The speaker 28 outputs, for example, information related to a warning or information related to an alert.

[0065] The autonomous driving ECU 11 stores a table in which obstacle detection ranges are registered for each shape of the intersection 2 and each traveling direction of the vehicle 1 at the intersection 2, as described with reference to FIGS. 1 to 3.

[0066] The driving assistance device 8 further includes various sensors such as a vehicle speed sensor (not shown in Fig. 5). The hardware configuration shown in Fig. 5 is an example, and various modifications are possible to achieve similar functions. Different sensors and actuators may be provided to achieve similar functions.

[0067] (Functional configuration of driving assistance device) The functional configuration of the driving assistance device 8 will be described with reference to Fig. 6. Fig. 6 is a functional block diagram showing an example of the functional configuration of the driving assistance device of the embodiment. Note that the functional block diagram of Fig. 6 shows the minimum configuration required for the autonomous driving ECU 11 to realize the contents of this embodiment.

[0068] The autonomous driving ECU 11 of the driving assistance device 8 causes its own CPU to execute a control program, thereby realizing as functional units a traffic light detection unit 31, a traveling direction identification unit 32, an obstacle detection range setting unit 33, an obstacle detection unit 34, and a vehicle control unit 35, all of which are shown in Fig. 6. Note that some or all of these functions of the autonomous driving ECU 11 may be realized by dedicated hardware.

[0069] The traffic light detection unit 31 repeatedly detects the traffic light 3 ahead of the vehicle 1, the light color of the traffic light 3, and the distance to the traffic light 3.

[0070] The traffic light detection unit 31, for example, compares an image captured by the camera 22 with a traffic light recognition model generated by deep learning to determine whether a traffic light 3 is captured in the image, and if so, to detect its light color (green, yellow, or red). The traffic light detection unit 31 also compares the measured current position and traveling direction of the vehicle 1 with the high-precision map database 26 to estimate the distance from the vehicle 1 to the traffic light 3 (intersection 2). The traffic light detection unit 31 repeatedly performs the above-mentioned process to update the positional relationship between the vehicle 1 and the intersection 2 as needed.

[0071] Furthermore, when the light color of the traffic light 3 is yellow, the traffic light detection unit 31 determines whether the vehicle 1 can pass through the traffic light 3 while the yellow light is on. For example, the traffic light detection unit 31 determines whether the vehicle 1 can pass through the traffic light 3 while the yellow light is on based on whether the vehicle 1 can travel the distance from the vehicle 1 to the traffic light 3 (intersection 2) in the approximately two seconds from when the green light of the traffic light 3 goes out to when the red light comes on.

[0072] Furthermore, the traffic light detection unit 31 determines whether the distance from the vehicle 1 to the traffic light 3 (to be precise, the intersection 2) is within a predetermined distance. The value of the predetermined distance is set, for example, based on the specifications of the camera 22 and the lidar 24, to a distance at which the driving assistance device 8 can detect obstacles around the intersection 2. The value of the predetermined distance may be a fixed value, or may be set to a longer predetermined distance as the vehicle speed of the vehicle 1 increases.

[0073] Furthermore, the traffic light detection unit 31 determines whether the vehicle 1 has passed through an intersection 2 that has a traffic light 3. The traffic light detection unit 31 determines whether the vehicle 1 has passed through an intersection 2 that has a traffic light 3, for example, by constantly monitoring the distance between the vehicle 1 and the detected traffic light 3.

[0074] The traveling direction identification unit 32 identifies the traveling direction of the vehicle 1 at the traffic light 3 detected by the traffic light detection unit 31.

[0075] Specifically, the traveling direction identification unit 32 identifies the traveling direction of the vehicle 1 at the nearest traffic light 3 (intersection 2) based on a preset traveling route of the vehicle 1. Note that the specific processing content performed by the traveling direction identification unit 32 is widely known through the route guidance function of car navigation systems.

[0076] The obstacle detection range setting unit 33 sets a detection range for obstacles at the intersection 2 where the traffic light 3 is located, based on the light color of the traffic light 3 detected by the traffic light detection unit 31 and the traveling direction of the vehicle 1 at the traffic light 3. The obstacle detection range setting unit 33 is an example of a setting unit in the present disclosure.

[0077] Specifically, the obstacle detection range setting unit 33 reads data corresponding to the shape of the intersection 2 and the direction of travel of the vehicle 1 at the intersection 2 from a table in which obstacle detection ranges are registered, which is stored in the autonomous driving ECU 11, and sets the obstacle detection range.

[0078] The obstacle detection unit 34 detects obstacles that exist within the detection range set by the obstacle detection range setting unit 33.

[0079] Specifically, the obstacle detection unit 34 specifies the relative position of the obstacle detection range as seen from the vehicle 1, as described in Fig. 4, based on the obstacle detection range read out by the obstacle detection range setting unit 33 and the current position of the vehicle 1. Then, the obstacle detection unit 34 detects obstacles such as automobiles, bicycles, motorcycles, pedestrians, and objects fallen on the road within the specified detection range using the lidar 24 and the camera 22.

[0080] Before the vehicle 1 enters the intersection 2, the vehicle control unit 35 controls the traveling state of the vehicle 1 based on the road alignment at the intersection 2, the light color of the traffic light 3, and the state of the obstacle detected by the obstacle detection unit 34. The vehicle control unit 35 is an example of a control unit in the present disclosure.

[0081] Specifically, when the light color of the traffic light 3 is red, the vehicle control unit 35 performs speed control (stop control) to stop the vehicle 1 at the stop line 5 or in front of the leading vehicle 6. Furthermore, when the light color of the traffic light 3 is green or yellow, the vehicle control unit 35 performs speed control and steering control to make the vehicle 1 travel along a predetermined travel route. At that time, if the presence of an obstacle in the traveling direction of the vehicle 1 is detected, the vehicle control unit 35 performs speed control (stop control) to stop the vehicle 1 in front of the obstacle.

[0082] (Processing flow performed by the driving assistance device) The flow of processing performed by the driving support device 8 will be described with reference to Fig. 7. Fig. 7 is a flowchart showing an example of the flow of processing performed by the driving support device of the embodiment.

[0083] The traffic light detection unit 31 determines whether a traffic light 3 has been detected (step S11). If it is determined that a traffic light 3 has been detected (step S11: Yes), the process proceeds to step S12. On the other hand, if it is not determined that a traffic light 3 has been detected (step S11: No), step S11 is repeated.

[0084] If it is determined in step S11 that a traffic light 3 has been detected, the traffic light detection unit 31 determines whether the light color of the traffic light 3 is green (step S12). If it is determined that the light color of the traffic light 3 is green (step S12: Yes), the process proceeds to step S13. On the other hand, if it is not determined that the light color of the traffic light 3 is green (step S12: No), the process proceeds to step S14.

[0085] If it is determined in step S12 that the light color of the traffic light 3 is green, the traveling direction identification unit 32 identifies the traveling direction of the vehicle 1 at the intersection 2 where the traffic light 3 is located (step S13). Then, the process proceeds to step S17.

[0086] On the other hand, if it is not determined in step S12 that the light color of the traffic light 3 is green, the traffic light detection unit 31 determines whether the light color of the traffic light 3 is yellow (step S14). If it is determined that the light color of the traffic light 3 is yellow (step S14: Yes), the process proceeds to step S15. On the other hand, if it is not determined that the light color of the traffic light 3 is yellow (step S14: No), that is, if the light color of the traffic light 3 is red, the process proceeds to step S16.

[0087] If it is determined in step S14 that the light color of the traffic light 3 is yellow, the traffic light detection unit 31 determines whether the vehicle 1 can pass through the traffic light 3 while the traffic light 3 is lit yellow (step S15). If it is determined that the vehicle 1 can pass through the traffic light 3 (step S15: Yes), the process proceeds to step S13. On the other hand, if it is not determined that the vehicle 1 can pass through the traffic light 3 (step S15: No), the process proceeds to step S16.

[0088] If it is not determined in step S14 that the light color of the traffic light 3 is yellow, or if it is not determined in step S15 that the vehicle 1 is able to pass through the traffic light 3, the vehicle control unit 35 performs stop control to stop the vehicle 1 at the stop line 5 of the intersection 2 where the traffic light 3 is located (step S16). Thereafter, the driving assistance device 8 ends the processing of Fig. 7. In practice, the driving assistance device 8 continues to execute the processing of Fig. 7 until the vehicle arrives at the destination by autonomous driving.

[0089] If a leading vehicle 6 is present ahead of the vehicle 1, the vehicle control unit 35 stops the vehicle 1 in front of the leading vehicle 6 in step S16.

[0090] Returning to step S13, the traffic light detection unit 31 determines whether the distance from the vehicle 1 to the intersection 2 is within a predetermined distance (step S17). If it is determined that the distance from the vehicle 1 to the intersection 2 is within the predetermined distance (step S17: Yes), the process proceeds to step S18. On the other hand, if it is not determined that the distance from the vehicle 1 to the intersection 2 is within the predetermined distance (step S17: No), the determination of step S17 is repeated.

[0091] In step S17, if it is determined that the distance from vehicle 1 to intersection 2 is within a predetermined distance, obstacle detection range setting unit 33 sets an obstacle detection range around intersection 2 according to the shape of intersection 2 and the direction of travel of vehicle 1 at intersection 2 (step S18).

[0092] Next, the obstacle detection unit 34 detects an obstacle within the detection range set by the obstacle detection range setting unit 33 (step S19).

[0093] The obstacle detection unit 34 determines whether an obstacle is present within the detection range based on the processing result of step S19 (step S20). If it is determined that an obstacle is present within the detection range (step S20: Yes), the process proceeds to step S21. On the other hand, if it is not determined that an obstacle is present within the detection range (step S20: No), the process proceeds to step S22.

[0094] If it is determined in step S20 that an obstacle is present within the detection range, the vehicle control unit 35 performs deceleration control of the vehicle 1 (step S21). At this time, if it is determined that contact between the vehicle 1 and the obstacle is imminent, the vehicle control unit 35 stops the vehicle 1. Thereafter, the process proceeds to step S23.

[0095] On the other hand, if it is determined in step S20 that no obstacle is present within the detection range, the vehicle control unit 35 continues the automatic driving of the vehicle 1 along the preset route (step S22), and then proceeds to step S23.

[0096] Following step S21 or step S22, the traffic light detection unit 31 determines whether the vehicle 1 has passed through the intersection 2 (step S23). If it is determined that the vehicle 1 has passed through the intersection 2 (step S23: Yes), the driving assistance device 8 ends the processing in Fig. 7. On the other hand, if it is not determined that the vehicle 1 has passed through the intersection 2 (step S23: No), the process returns to step S19 and the above-mentioned processing is repeated.

[0097] (Effects of the embodiment) As described above, the driving assistance device 8 of the embodiment includes: a traffic light detection unit 31 that repeatedly detects the traffic light 3 ahead of the vehicle 1, the light color of the traffic light 3, and the distance to the traffic light 3; a traveling direction identification unit 32 that identifies the traveling direction of the vehicle 1 at the traffic light 3; an obstacle detection range setting unit 33 (setting unit) that sets a detection range for obstacles at the intersection 2 where the traffic light 3 is located in accordance with the light color of the traffic light 3 and the traveling direction of the vehicle 1 at the traffic light 3; an obstacle detection unit 34 that detects obstacles present within the detection range set by the obstacle detection range setting unit 33; and a vehicle control unit 35 (control unit) that controls the traveling state of the vehicle 1 based on the road alignment at the intersection 2, the light color of the traffic light 3, and the state of the obstacle detected by the obstacle detection unit 34, from before the vehicle 1 enters the intersection 2. Therefore, before passing through the intersection 2 where the traffic light 3 is located, it is possible to detect obstacles in a range related to the traveling direction of the vehicle 1, and therefore it is possible to predict the state of obstacles in the traveling direction of the vehicle 1. This makes it possible to prevent a delay in detecting an obstacle when passing through the intersection 2. Furthermore, since the obstacle detection range can be limited, the calculation load can be reduced.

[0098] Furthermore, in the driving assistance device 8 of the embodiment, the obstacle detection unit 34 starts detecting an obstacle when the vehicle 1 reaches a point a predetermined distance before the traffic light 3. Therefore, it is possible to start detecting obstacles in a range according to the traveling direction of the vehicle 1 before the vehicle 1 enters the intersection 2. This allows the driving assistance device 8 to control the traveling of the vehicle 1 with ample time to spare.

[0099] Furthermore, in the driving assistance device 8 of the embodiment, the vehicle control unit 35 (control unit) at least determines whether to stop or pass the vehicle 1 at the intersection 2, and controls the traveling direction and vehicle speed of the vehicle 1. Therefore, the vehicle 1 can be smoothly controlled at the intersection 2.

[0100] Although the embodiments of the present invention have been described above, the above-described embodiments are presented as examples and are not intended to limit the scope of the present invention. This novel embodiment can be embodied in various other forms. Furthermore, various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. Furthermore, this embodiment is included within the scope and spirit of the invention, and is also included in the inventions and their equivalents described in the claims. [Explanation of symbols]

[0101] 1 vehicle 2 intersections 3a,3b,3c,3d traffic light 4a, 4b, 4c, 4d Crosswalks 5 stop line 6 Leading vehicle 8 Driving assistance devices 10a, 10b, 10c, 10d, 10e, 10f, 10g, 10h, 10i Detection range 31 Traffic light detector 32 Travel direction identification part 33 Obstacle detection range setting unit (setting unit) 34 Obstacle detection unit 35 Vehicle control unit (control unit) D, Da, Db distance θ,θa,θb Argument

Claims

1. a traffic light detection unit that repeatedly detects a traffic light at an intersection ahead of the vehicle, the light color of the traffic light, and the distance to the traffic light; a traveling direction identification unit that identifies a traveling direction of the vehicle at the intersection with a traffic light; a setting unit that sets a limited detection range from the detection range of an obstacle detection sensor equipped in the vehicle in the traveling direction of the vehicle at the intersection with traffic lights and in a direction intersecting the traveling direction of the vehicle at the intersection with traffic lights, depending on the light color of the traffic lights and the traveling direction of the vehicle at the intersection with traffic lights; an obstacle detection unit that starts detecting obstacles present within the detection range set by the setting unit when the vehicle reaches a point a predetermined distance before the intersection with the traffic light; a control unit that controls a traveling state of the vehicle based on the road alignment of the intersection, the light color of the traffic light, and the state of the obstacle detected by the obstacle detection unit, from before the vehicle enters the intersection. Driving assistance device.

2. the setting unit further sets an obstacle detection range for a right-turn lane of an oncoming traffic lane in accordance with a light color of the traffic light when the vehicle turns left at the intersection with a traffic light. The driving assistance device according to claim 1 .

3. The control unit at least determines whether to stop or pass the vehicle at the intersection and controls the traveling direction and speed of the vehicle. The driving assistance device according to claim 1 or 2.

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