Automatic driving vehicle

Abstract

To provide an automatic driving vehicle capable of traveling at a safer-conscious intersection, when starting a vehicle stopped just before the intersection according to a traffic situation ahead when a lighting state of a traffic signal is lighted in blue.SOLUTION: An automatic driving vehicle recognizes a lighting state of a traffic signal at an intersection in front of a self-lane, recognizes a space between a preceding vehicle and the intersection, and stops an own vehicle just before the intersection when the lighting state is lighted in blue, and the own vehicle is not possible to pass through the intersection. In a case where the own vehicle is possible to pass through the intersection from a state where the own vehicle is not possible to pass therethrough in a state where the lighting state is lighted in blue, the own vehicle is made to travel by limiting an acceleration or a vehicle speed of the own vehicle by a third upper limit value smaller than a second upper limit value in a case where a crossing / oncoming vehicle is not a two-wheeled vehicle, when the crossing / oncoming vehicle is the two-wheeled vehicle while starting the own vehicle that has been stopped just before the intersection when there is the crossing / oncoming vehicle that turns right or left at the intersection so as to cross the self-lane.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to autonomous vehicles. [Background technology]

[0002] Patent document 1 discloses a driving assistance device that determines that the vehicle cannot pass through if there is not enough space available for the vehicle to enter while the traffic light is green, based on the location and shape of the intersection and the position and dimensions of the vehicle ahead. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-165643 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned conventional technology, in which a vehicle stops before an intersection depending on traffic conditions ahead even when the traffic light is green, there is room for improvement in order to pass through an intersection more safely when a vehicle that has been stopped before the intersection is started to move forward.

[0005] The present invention aims to provide an autonomous vehicle that can travel through an intersection in a safer manner when the vehicle is stopped before the intersection in accordance with the traffic conditions ahead when the traffic light is green. [Means for solving the problem]

[0006] An autonomous vehicle according to one aspect of the present invention includes a traffic light state recognition unit that recognizes the lighting state of a traffic light at an intersection ahead of the host vehicle's lane based on the detection results of an on-board external sensor, a space recognition unit that recognizes a space between the intersection and a preceding vehicle located ahead of the host vehicle in a straight-ahead direction of the intersection based on the detection results of the external sensor, a passage determination unit that determines whether the host vehicle can pass through the intersection based on the space, and a vehicle control unit that stops the host vehicle before the intersection when the lighting state is blue and the host vehicle cannot pass through the intersection, and the vehicle control unit When the light is on green and the vehicle is able to pass through an intersection after being unable to do so, and there is an oncoming vehicle attempting to turn right or left at the intersection across the vehicle's lane, the vehicle that has been stopped in front of the intersection is started, and the vehicle is allowed to travel with its acceleration or speed limited to a second upper limit value that is smaller than the first upper limit value when there is no oncoming vehicle, and when the oncoming vehicle is a motorcycle, the vehicle is allowed to travel with its acceleration or speed limited to a third upper limit value that is smaller than the second upper limit value when the oncoming vehicle is not a motorcycle.

[0007] In an autonomous vehicle according to one aspect of the present invention, when the traffic light at the intersection ahead of the vehicle's lane is green and the vehicle is able to pass through the intersection instead of being unable to pass through, the autonomous vehicle starts the vehicle that has been stopped before the intersection. At this time, if there is an oncoming vehicle trying to turn right or left at the intersection so as to cross the vehicle's lane, and the oncoming vehicle is a motorcycle, the vehicle is caused to travel by limiting the acceleration or speed of the vehicle to a third upper limit value that is smaller than the second upper limit value when the oncoming vehicle is not a motorcycle. As a result, when the oncoming vehicle is a motorcycle, the autonomous vehicle travels through the intersection with greater consideration for safety than when the oncoming vehicle is not a motorcycle. Therefore, when the traffic light is green and the vehicle that has been stopped before the intersection is started according to the traffic conditions ahead, the vehicle can travel through the intersection with greater consideration for safety.

[0008] In one embodiment, the vehicle control unit may run the host vehicle by limiting the acceleration or speed of the host vehicle by the second upper limit value or the third upper limit value until the host vehicle passes the oncoming crossing vehicle, and may run the host vehicle by limiting the acceleration or speed of the host vehicle by the first upper limit value after the host vehicle passes the oncoming crossing vehicle. In this case, it is possible to ensure safety until the host vehicle passes the oncoming crossing vehicle, and to ensure smooth running through the intersection after the host vehicle passes the oncoming crossing vehicle. Effect of the Invention

[0009] According to the present invention, when a vehicle is stopped before an intersection depending on the traffic conditions ahead and the traffic light is on green, the vehicle can be driven through the intersection with greater consideration given to safety. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a functional block diagram illustrating an autonomous driving vehicle according to an embodiment. [Diagram 2] 10 is a diagram illustrating an example of the vehicle speed of the host vehicle when the host vehicle is started after being stopped; [Diagram 3] 10 is a flowchart showing an example of processing by an autonomous driving ECU. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, exemplary embodiments will be described with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference numerals, and duplicated description may be omitted.

[0012] Fig. 1 is a functional block diagram illustrating an autonomous vehicle according to an embodiment. As shown in Fig. 1, a vehicle (host vehicle) 1 is a vehicle such as a passenger car, and is an autonomous vehicle equipped with an autonomous driving system. The autonomous driving system drives the vehicle 1 autonomously.

[0013] Autonomous driving is a driving state in which the vehicle 1 is automatically driven along the road on which the vehicle 1 is traveling. Autonomous driving includes, for example, a driving state in which the vehicle 1 is automatically driven toward a preset destination without the driver performing driving operations. Autonomous driving includes, for example, autonomous driving levels 2 to 4 in SAE [Society of Automotive Engineers] J3016. The destination may be set by a passenger such as a driver, or may be automatically set by the vehicle 1. Autonomous driving may be vehicle control in which the vehicle 1 is automatically driven along a road without setting a destination. In autonomous driving, the vehicle 1 runs automatically without the driver having to perform driving operations. The autonomous driving here includes automatically stopping the vehicle 1 before an intersection in front of the lane in which the vehicle 1 is traveling, according to the traffic conditions ahead of the intersection, even if the traffic light is green at the intersection.

[0014] The vehicle 1 includes an external sensor 2, an internal sensor 3, a map database 4, a GPS receiver 5, an actuator 6, and an autonomous driving ECU [Electronic Control Unit] 10.

[0015] The external sensor 2 is a detection device that detects the situation around the vehicle 1 (external environment of the vehicle). The external sensor 2 includes at least a camera that captures an image in front of the vehicle 1. The external sensor 2 may include a radar sensor. The external sensor 2 may be configured to reconstruct various properties of the external environment in which the vehicle 1 is traveling (such as the position of the vehicle, the relative distance to other vehicles, the relative speed to other vehicles, the orientation of other vehicles, the shape of the lanes, and the lighting status of traffic lights).

[0016] The camera is an imaging device that captures an image of the external environment of the vehicle 1. The camera is provided behind the windshield of the vehicle 1. The camera transmits imaging information related to the external environment of the vehicle 1 to the autonomous driving ECU 10. The camera may be a monocular camera or a stereo camera. The stereo camera has two imaging units arranged to reproduce binocular parallax. The imaging information of the stereo camera also includes information in the depth direction.

[0017] A radar sensor is a detection device that detects objects around the vehicle 1 using radio waves (e.g., millimeter waves) or light. Radar sensors include, for example, millimeter wave radars and LiDARs (Light Detection and Ranging). The radar sensor detects objects by transmitting radio waves or light to the vicinity of the vehicle 1 and receiving the radio waves or light reflected by the objects. The radar sensor transmits information about the detected objects to the autonomous driving ECU 10.

[0018] The internal sensor 3 is a detection device that detects the traveling state of the vehicle 1. The internal sensor 3 includes a vehicle speed sensor. The vehicle speed sensor is a detector that detects the speed of the vehicle 1. As the vehicle speed sensor, for example, a known wheel speed sensor may be used. The vehicle speed sensor transmits the detected vehicle speed information to the autonomous driving ECU 10.

[0019] The internal sensor 3 may include a known acceleration sensor and a yaw rate sensor. The acceleration sensor is a detector that detects the acceleration of the vehicle 1. The acceleration sensor transmits acceleration information of the vehicle 1 to the autonomous driving ECU 10. The yaw rate sensor is a detector (e.g., a gyro sensor) that detects a yaw rate (rotational angular velocity) around the vertical axis of the center of gravity of the vehicle 1. The yaw rate sensor transmits the detected yaw rate information of the vehicle to the autonomous driving ECU 10.

[0020] The map database 4 is a storage device that stores map information. The map database 4 is formed in a storage medium such as a HDD (Hard Disk Drive) mounted on the vehicle 1. The map information includes information such as the positions and shapes of roads, intersections, and branching points (for example, the positions and shapes of intersections, the widths of lanes, the positions of dividing lines and crosswalks, etc.). The map information may also include information on structures (such as the positions and types of traffic lights installed at intersections) and various types of traffic rule information (such as one-way streets, no right or left turns, and no turns). Note that a part of the map information included in the map database 4 may be stored in a storage device other than the HDD. The map database 4 may be formed in a computer in a facility such as a management center that can communicate with the vehicle 1.

[0021] The GPS receiver 5 receives signals from three or more GPS satellites to obtain position information indicating the position of the vehicle 1. The position information includes, for example, latitude and longitude. Instead of the GPS receiver 5, other means capable of identifying the latitude and longitude at which the vehicle 1 is located may be used.

[0022] The actuator 6 is a device used for automatic driving control of the vehicle 1. The actuator 6 includes at least a drive actuator, a brake actuator, and a steering actuator. The drive actuator controls the amount of air supplied to the engine (throttle opening) in response to a control signal from the automatic driving ECU 10, for example, to control the driving force of the vehicle 1. If the vehicle 1 is a hybrid vehicle, in addition to the amount of air supplied to the engine, a control signal from the automatic driving ECU 10 is input to a motor serving as a power source to control the driving force. If the vehicle 1 is an electric vehicle, a control signal from the automatic driving ECU 10 is input to a motor serving as a power source to control the driving force. The motor serving as a power source in these cases constitutes the actuator 6.

[0023] The brake actuator controls the brake system in response to a control signal from the autonomous driving ECU 10, and controls the braking force applied to the wheels of the vehicle 1. For example, a hydraulic brake system can be used as the brake system. The steering actuator controls the drive of an assist motor that controls the steering torque of the electric power steering system in response to a control signal from the autonomous driving ECU 10. As a result, the steering actuator controls the steering torque in response to a control signal from the autonomous driving ECU 10.

[0024] The automatic driving ECU 10 is a main component of the automatic driving system. The automatic driving ECU 10 executes automatic driving control of the vehicle 1. The automatic driving ECU 10 is an electronic control unit having a CPU [Central Processing Unit], a ROM [Read Only Memory], a RAM [Random Access Memory], a CAN [Controller Area Network] communication circuit, and the like. The automatic driving ECU 10 is connected to a network that communicates using, for example, a CAN communication circuit, and is communicatively connected to the components of the vehicle 1 described above. The automatic driving ECU 10, for example, operates the CAN communication circuit based on a signal output by the CPU to input and output data, stores the data in the RAM, loads a program stored in the ROM into the RAM, and executes the program loaded into the RAM by the CPU, thereby realizing an automatic driving function. The automatic driving ECU 10 may be composed of multiple electronic units.

[0025] Next, a description will be given of an example of a functional configuration of the autonomous driving ECU 10. The autonomous driving ECU 10 has an autonomous driving control unit 11, a space recognition unit 12, a passage determination unit 13, and a vehicle control unit .

[0026] The autonomous driving control unit 11 recognizes the external environment of the vehicle 1 based on the detection results of the external sensor 2 (images captured by a camera or object information detected by a radar sensor). The external environment includes the relative positions of surrounding objects with respect to the vehicle 1. The external environment may also include the relative speed and movement direction of surrounding objects with respect to the vehicle 1. The autonomous driving control unit 11 recognizes objects such as other vehicles and traffic lights by pattern matching or the like. The other vehicles include a preceding vehicle located ahead of the vehicle 1 in the straight-ahead direction of the intersection. The autonomous driving control unit 11 functions as a traffic light state recognition unit that recognizes the lighting state of the traffic lights at the intersection ahead of the vehicle's lane (hereinafter, may be simply referred to as "traffic light lighting state") based on the detection results of the on-board external sensor 2.

[0027] The autonomous driving control unit 11 recognizes the driving state of the vehicle 1 based on the detection result of the internal sensor 3. The driving state includes, for example, the speed of the vehicle 1, the acceleration of the vehicle 1, and the yaw rate of the vehicle 1. The autonomous driving control unit 11 acquires the road environment around the vehicle 1 (for example, road shape, intersection shape, type of traffic light, etc.) based on, for example, map information.

[0028] The autonomous driving control unit 11 acquires the current vehicle position of the vehicle 1 based on, for example, position information from the GPS receiving unit 5. The autonomous driving control unit 11 may acquire the current vehicle position of the vehicle 1 by SLAM technology. The autonomous driving control unit 11 may acquire the current vehicle position of the vehicle 1 by other known methods.

[0029] The automatic driving control unit 11 executes automatic driving of the vehicle 1. The automatic driving control unit 11 generates a course of the vehicle 1 based on, for example, a target route, the position of the vehicle 1, the external environment of the vehicle 1, and the driving state of the vehicle 1. The course corresponds to a driving plan for automatic driving. The course includes, for example, a route [path] along which the vehicle travels in automatic driving and a vehicle speed plan in automatic driving. The route is a trajectory along which the vehicle is scheduled to travel during automatic driving on a target route instructed to the automatic parking system. The route can be, for example, data on the steering angle and vehicle speed of the vehicle 1 (steering angle plan and vehicle speed plan) set at predetermined intervals on the target route. The automatic driving control unit 11 controls the actuator 6 to follow the driving plan for automatic driving, and executes automatic driving of the vehicle 1.

[0030] Based on the detection result of the external sensor 2, the space recognition unit 12 recognizes the space between the preceding vehicle located ahead of the intersection in the straight-ahead direction relative to the vehicle 1 and the intersection. The shape of the intersection may be a crossroads, a Y-shaped intersection, or the like, and is not particularly limited. The straight-ahead direction at the intersection is not limited to the straight-ahead direction at a crossroads or the like, and may include the road direction at a Y-shaped intersection or the like. The space between the preceding vehicle and the intersection may be, for example, the distance between the rear end position of the preceding vehicle and the edge (the edge closer to the preceding vehicle) of the road marking that forms the crosswalk when the preceding vehicle is located ahead of the crosswalk located ahead of the intersection in the straight-ahead direction.

[0031] The passage determination unit 13 determines whether or not the vehicle 1 can pass through the intersection based on the space (hereinafter, simply referred to as "space") between the intersection and a preceding vehicle located ahead of the intersection in the straight-ahead direction relative to the vehicle 1. "The vehicle 1 can pass through the intersection" means that the vehicle 1 can complete passing through the intersection in the straight-ahead direction and can stop without physically going beyond the intersection.

[0032] The passage determination unit 13 determines that the vehicle 1 can pass through the intersection, for example, when the space is greater than or equal to a length threshold, which is the length obtained by adding a predetermined margin distance to the front-to-rear length of the vehicle 1. The passage determination unit 13 determines that the vehicle 1 cannot pass through the intersection, for example, when the space is smaller than the length threshold and the passage determination unit 13 has determined that the vehicle 1 cannot pass through the intersection. When the space becomes greater than or equal to the length threshold as a result of the preceding vehicle moving forward, the passage determination unit 13 determines that the vehicle 1 can pass through the intersection.

[0033] When the traffic light is green and the vehicle 1 cannot pass through the intersection, the vehicle control unit 14 stops the vehicle 1 in front of the intersection. When the traffic light is green and the vehicle 1 cannot pass through the intersection but can, the vehicle control unit 14 starts the vehicle 1 that has been stopped in front of the intersection.

[0034] The vehicle control unit 14 recognizes an oncoming crossing vehicle by a known method, for example, based on image information from the camera of the external sensor 2. The oncoming crossing vehicle is an oncoming vehicle that is about to turn right or left at the intersection so as to cross the own lane. The oncoming crossing vehicle may be an oncoming vehicle in the right turn lane or the left turn lane. When there is no right turn lane or the left turn lane, the oncoming crossing vehicle may be an oncoming vehicle that is blinking its turn signal so as to cross the own lane at the intersection in the oncoming lane. The vehicle control unit 14 recognizes the presence or absence of an oncoming crossing vehicle and the type of the oncoming crossing vehicle. The vehicle control unit 14 at least recognizes whether the oncoming crossing vehicle is a two-wheeled vehicle or not.

[0035] When the traffic light is green and vehicle 1 is able to pass through an intersection after being unable to do so (hereinafter, sometimes simply referred to as "when vehicle 1 is able to pass through after being unable to do so"), and there is no oncoming vehicle crossing, vehicle control unit 14 causes vehicle 1 to travel by limiting the acceleration or vehicle speed of vehicle 1 at a first upper limit value.

[0036] The first upper limit value is a limit value of the acceleration or vehicle speed of the vehicle 1 used when there is no oncoming vehicle crossing when the state becomes passable from impassable. The first upper limit value may be an upper limit value of the acceleration or vehicle speed of the vehicle 1 in normal automatic driving in response to a situation where there is no oncoming vehicle crossing. FIG. 2 is a diagram illustrating the vehicle speed of the host vehicle when the host vehicle is started after being stopped. As shown in FIG. 2, the vehicle control unit 14 drives the vehicle 1 by setting the acceleration to be equal to or less than the first acceleration upper limit value (the first upper limit value, corresponding to the inclined portion of the dashed line L1) until the vehicle speed reaches the first vehicle speed upper limit value (the first upper limit value, corresponding to the horizontal portion of the dashed line L1), for example.

[0037] When the intersection becomes passable from an impassable state, and there is an oncoming crossing vehicle other than a motorcycle, the vehicle control unit 14 restricts the acceleration or vehicle speed of the vehicle 1 at a second upper limit value and causes the vehicle 1 to travel. That is, when the traffic light is green and the vehicle 1 is allowed to travel through the intersection from an impassable state, and there is an oncoming crossing vehicle attempting to turn right or left at the intersection so as to cross the vehicle's own lane, the vehicle control unit 14 starts the vehicle 1 stopped in front of the intersection, and restricts the acceleration or vehicle speed of the vehicle 1 at a second upper limit value that is smaller than the first upper limit value when there is no oncoming crossing vehicle, and causes the vehicle 1 to travel.

[0038] The second upper limit value is a limit value of the acceleration or vehicle speed of the vehicle 1 used when the vehicle becomes passable from being unable to pass and there is an oncoming vehicle crossing, excluding motorcycles. The second upper limit value may be a value smaller than the upper limit value of the acceleration or vehicle speed of the vehicle 1 in normal automatic driving, in response to a situation where there is an oncoming vehicle crossing, excluding motorcycles. As shown in FIG. 2, the vehicle control unit 14 drives the vehicle 1, for example, by setting the acceleration to be equal to or less than the second acceleration upper limit value (second upper limit value, corresponding to the inclined portion of the dashed dotted line L2) until the vehicle speed reaches the second vehicle speed upper limit value (second upper limit value, corresponding to the horizontal portion of the dashed dotted line L2).

[0039] When the oncoming vehicle crossing changes from impassable to passable and there is a two-wheeled vehicle, the vehicle control unit 14 starts the vehicle 1 stopped in front of the intersection and limits the acceleration or vehicle speed of the vehicle 1 to a third upper limit value that is smaller than the second upper limit value, and causes the vehicle 1 to travel. In other words, when the oncoming vehicle crossing is a two-wheeled vehicle, the vehicle control unit 14 causes the vehicle 1 to travel by limiting the acceleration or vehicle speed of the vehicle 1 to a third upper limit value that is smaller than the second upper limit value when the oncoming vehicle crossing is not a two-wheeled vehicle.

[0040] The third upper limit value is a limit value of the acceleration or vehicle speed of the vehicle 1 used when an oncoming crossing vehicle that is a two-wheeled vehicle is present when the vehicle becomes passable from being unable to pass. The third upper limit value may be an upper limit value of the acceleration or vehicle speed of the vehicle 1 that is set in consideration of the tendency of an oncoming crossing vehicle that is a two-wheeled vehicle to jump out into the vehicle's own lane before passing the vehicle 1, for example, by making a quick right or left turn. As shown in Fig. 2, the vehicle control unit 14 drives the vehicle 1 with the acceleration set to be equal to or lower than the third acceleration upper limit value (the third upper limit value, corresponding to the inclined portion of the solid line L3) until the vehicle speed reaches the third vehicle speed upper limit value (the third upper limit value, corresponding to the horizontal portion of the solid line L3).

[0041] For example, the vehicle control unit 14 may determine whether the vehicle 1 has not yet passed the oncoming crossing vehicle based on the recognition result of the oncoming crossing vehicle. The vehicle control unit 14 may limit the acceleration or vehicle speed of the vehicle 1 to the second upper limit value or the third upper limit value and cause the vehicle 1 to travel until the vehicle 1 passes the oncoming crossing vehicle. After the vehicle 1 has passed the oncoming crossing vehicle, the vehicle control unit 14 may limit the acceleration or vehicle speed of the vehicle 1 to the first upper limit value and cause the vehicle 1 to travel.

[0042] Next, the processing of the autonomous driving ECU 10 will be described with reference to Fig. 3. Fig. 3 is a flowchart showing an example of processing of the autonomous driving ECU. For example, during autonomous driving of the vehicle 1, when the vehicle 1 is in a state where it was unable to pass through an intersection but is now able to pass through it, the flowchart shown in Fig. 3 is repeatedly executed at predetermined intervals during a period from when the vehicle 1, which has been stopped in front of the intersection, starts to move until the vehicle 1 has passed through the intersection.

[0043] 3, in step S11, the autonomous driving ECU 10 recognizes an oncoming vehicle crossing the road by using the vehicle control unit 14. The vehicle control unit 14 recognizes the oncoming vehicle crossing the road by using a known method, for example, based on image information captured by the camera of the external sensor 2.

[0044] In S12, the autonomous driving ECU 10 determines whether or not there is an oncoming crossing vehicle by the vehicle control unit 14. The vehicle control unit 14 determines whether or not there is an oncoming crossing vehicle based on, for example, a recognition result of the oncoming crossing vehicle.

[0045] When it is determined that there is no oncoming crossing vehicle (S12: NO), the autonomous driving ECU 10 proceeds to processing in S13. In S13, the autonomous driving ECU 10 causes the vehicle control unit 14 to limit the acceleration or vehicle speed to a first upper limit value and drive the vehicle 1. For example, the vehicle control unit 14 drives the vehicle 1 with the acceleration set to a first acceleration upper limit value (first upper limit value) or less until the vehicle speed reaches the first vehicle speed upper limit value (first upper limit value). Thereafter, the autonomous driving ECU 10 ends the processing in FIG. 3.

[0046] On the other hand, if the autonomous driving ECU 10 determines that an oncoming crossing vehicle is present (S12: YES), the autonomous driving ECU 10 proceeds to processing in S14. In S14, the autonomous driving ECU 10 determines whether or not the vehicle 1 is about to pass an oncoming crossing vehicle through the vehicle control unit 14. The vehicle control unit 14 determines whether or not the vehicle 1 is about to pass an oncoming crossing vehicle based on, for example, the recognition result of the oncoming crossing vehicle.

[0047] If it is determined that vehicle 1 is not about to pass an oncoming vehicle crossing (vehicle 1 is about to pass an oncoming vehicle crossing) (S14: NO), the autonomous driving ECU 10 proceeds to the processing of S13 described above, and then terminates the processing of FIG. 3.

[0048] On the other hand, if the autonomous driving ECU 10 determines that the vehicle 1 has not yet passed the oncoming crossing vehicle (S14: YES), the autonomous driving ECU 10 proceeds to processing at S15. At S15, the autonomous driving ECU 10 determines whether or not the oncoming crossing vehicle is a two-wheeled vehicle by the vehicle control unit 14. The vehicle control unit 14 determines whether or not the oncoming crossing vehicle is a two-wheeled vehicle based on, for example, the recognition result of the oncoming crossing vehicle.

[0049] When it is determined that the oncoming crossing vehicle is not a two-wheeled vehicle (S15: NO), the automatic driving ECU 10 proceeds to processing of S16. In S16, the automatic driving ECU 10 causes the vehicle control unit 14 to limit the acceleration or vehicle speed to the second upper limit value and drive the vehicle 1. For example, the vehicle control unit 14 drives the vehicle 1 with the acceleration set to equal to or less than the second acceleration upper limit value (second upper limit value) until the vehicle speed reaches the second vehicle speed upper limit value (second upper limit value). Thereafter, the automatic driving ECU 10 ends the processing of FIG. 3.

[0050] On the other hand, when the autonomous driving ECU 10 determines that the oncoming crossing vehicle is a two-wheeled vehicle (S15: YES), the autonomous driving ECU 10 proceeds to processing in S17. In S17, the autonomous driving ECU 10 causes the vehicle control unit 14 to limit the acceleration or vehicle speed to the third upper limit value and drive the vehicle 1. For example, the vehicle control unit 14 drives the vehicle 1 with the acceleration set to equal to or less than the third acceleration upper limit value (third upper limit value) until the vehicle speed reaches the third vehicle speed upper limit value (third upper limit value). Thereafter, the autonomous driving ECU 10 ends the processing in FIG. 3.

[0051] Note that the autonomous driving ECU 10 may end the process of FIG. 3 midway once the vehicle 1 has passed through the intersection.

[0052] As described above, when the traffic light at the intersection ahead of the own lane is green and the vehicle 1 is able to pass through the intersection instead of being unable to pass through, the autonomous driving ECU 10 starts the vehicle 1 that has been stopped in front of the intersection. At this time, when there is an oncoming vehicle that is about to turn right or left at the intersection so as to cross the own lane, and the oncoming vehicle is a two-wheeled vehicle, the vehicle 1 is caused to travel by restricting the acceleration or vehicle speed of the vehicle 1 to a third upper limit value that is smaller than the second upper limit value when the oncoming vehicle is not a two-wheeled vehicle. Specifically, the vehicle control unit 14 causes the vehicle 1 to travel with the acceleration set to the third acceleration upper limit value (third upper limit value) or less until the vehicle speed reaches the third vehicle speed upper limit value (third upper limit value). As a result, when the oncoming vehicle is a two-wheeled vehicle, the vehicle 1 travels through the intersection with greater consideration given to safety than when the oncoming vehicle is not a two-wheeled vehicle. Here, a two-wheeled vehicle acting as an oncoming vehicle crossing is lighter than, for example, a four-wheeled vehicle and tends to jump into the vehicle's own lane before passing the vehicle 1 by making a quick right or left turn, etc. Therefore, by limiting the acceleration of the vehicle 1 by the third upper limit value, it becomes easier for the oncoming vehicle crossing to recognize the start of the vehicle 1. Alternatively, by limiting the vehicle speed of the vehicle 1 by the third upper limit value, it becomes easier for the vehicle 1 to stop. Therefore, when a vehicle that has been stopped before the intersection in accordance with the traffic conditions ahead when the traffic light is green is started, it is possible to drive through the intersection with greater consideration given to safety.

[0053] The vehicle control unit 14 causes the vehicle 1 to travel by limiting the acceleration or vehicle speed of the vehicle 1 at the second upper limit value or the third upper limit value until the vehicle 1 passes the oncoming crossing vehicle, and causes the vehicle 1 to travel by limiting the acceleration or vehicle speed of the vehicle 1 at the first upper limit value after the vehicle 1 passes the oncoming crossing vehicle. This allows for greater consideration to be given to safety until the vehicle 1 passes the oncoming crossing vehicle, while allowing the vehicle 1 to travel smoothly through the intersection after the vehicle 1 has passed the oncoming crossing vehicle.

[0054] [Variations] Although various exemplary embodiments have been described above, various omissions, substitutions, and modifications may be made without being limited to the above-described exemplary embodiments.

[0055] For example, in the above embodiment, after the vehicle 1 passes the oncoming crossing vehicle, the acceleration or vehicle speed of the vehicle 1 is limited to the first upper limit value and the vehicle 1 is allowed to travel, but this is not limited to this. For example, after the vehicle 1 passes the oncoming crossing vehicle, the limit value may be gradually increased from the second upper limit value or the third upper limit value to the first upper limit value. Alternatively, the limit may be released immediately after the vehicle 1 passes the oncoming crossing vehicle.

[0056] In the above embodiment, the autonomous driving ECU 10 ends the process of Fig. 3 when the vehicle 1 has passed through the intersection, but this is not limited to the above. For example, the autonomous driving ECU 10 may end the process of Fig. 3 when the vehicle 1 has passed a predetermined position (e.g., a midpoint) in the intersection.

[0057] In the above embodiment, it is assumed that the preceding vehicle ahead of the intersection in the vehicle's lane is stopped, but the preceding vehicle may be traveling at a very slow speed. In short, the space recognition unit 12 only needs to recognize the space between the preceding vehicle located ahead of the intersection in the straight-ahead direction and the intersection, and the passage determination unit 13 only needs to determine whether the vehicle 1 can pass through the intersection. [Explanation of symbols]

[0058] 1...vehicle (own vehicle, autonomous vehicle), 2...external sensor, 11...autonomous driving control unit (traffic light state recognition unit), 12...space recognition unit, 13...passing determination unit, 14...vehicle control unit.

Claims

1. a traffic light status recognition unit that recognizes the lighting status of a traffic light at an intersection ahead of the vehicle based on a detection result of an external sensor mounted on the vehicle; a space recognition unit that recognizes a space between the intersection and a preceding vehicle located ahead of the own vehicle in a straight-ahead direction of the intersection based on a detection result of the external sensor; a passage determination unit that determines whether or not the host vehicle can pass through the intersection based on the space; a vehicle control unit that stops the host vehicle before the intersection when the lighting state is blue lighting and the host vehicle cannot pass through the intersection, The vehicle control unit includes: When the illumination state is a green illumination state and the vehicle is able to pass through the intersection from a state in which the vehicle was unable to pass through, and when there is an oncoming vehicle attempting to turn right or left at the intersection so as to cross the vehicle's lane, the vehicle that has been stopped in front of the intersection is started, and the vehicle is allowed to travel by limiting the acceleration or vehicle speed of the vehicle to a second upper limit value that is smaller than a first upper limit value when there is no oncoming vehicle; When the oncoming crossing vehicle is a two-wheeled vehicle, the autonomous vehicle is caused to travel by limiting the acceleration or speed of the host vehicle to a third upper limit value that is smaller than the second upper limit value when the oncoming crossing vehicle is not a two-wheeled vehicle.

2. 2. The autonomous vehicle according to claim 1, wherein the vehicle control unit drives the host vehicle by limiting the acceleration or vehicle speed of the host vehicle at the second upper limit value or the third upper limit value until the host vehicle passes the oncoming vehicle, and drives the host vehicle by limiting the acceleration or vehicle speed of the host vehicle at the first upper limit value after the host vehicle passes the oncoming vehicle.

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