Driving control method and driving control device

Abstract

To provide a travel control method and travel control device capable of preventing an own vehicle from obstructing the traveling of an oncoming vehicle when the oncoming vehicle is recognized in a scene where the own vehicle makes a lane change to an opposite lane, following a preceding vehicle, and passes a plurality of obstacles on an own lane.SOLUTION: In a travel control method, when avoiding a first obstacle on an own lane, an own vehicle is allowed to make a lane change to an opposite lane. If there is a second obstacle located on the own lane beyond the first obstacle in the travel direction of the own vehicle, it is determined whether there is an evacuation section to which the own vehicle may evacuate, between the first obstacle and the second obstacle. When an oncoming vehicle traveling on the opposite lane is recognized after a preceding vehicle starts a lane change from the opposite lane to the own lane, and the own vehicle is traveling on the opposite lane, if there is the evacuation section, and there is a possibility that the own vehicle may get close to the oncoming vehicle, the own vehicle is moved into the evacuation section.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a driving control method and a driving control device.

Background Art

[0002] When the host vehicle is changing lanes to the oncoming lane and overtaking other vehicles in its own lane, if it is determined that the collision time until the host vehicle collides with an oncoming vehicle is less than or equal to the overtaking completion time, a technique is known in which braking control is executed on the host vehicle to decelerate it (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a scenario where the host vehicle changes lanes to the oncoming lane following a preceding vehicle and overtakes a plurality of obstacles on its own lane, while the host vehicle is traveling on the oncoming lane, a blind spot may occur due to the preceding vehicle, and the timing for recognizing an oncoming vehicle may be delayed. Therefore, in the above overtaking scenario, in Patent Document 1, before the host vehicle returns to its own lane, the preceding vehicle completes overtaking first and returns to its own lane, and at the timing when the host vehicle recognizes the oncoming vehicle, the host vehicle executes braking control, which may interfere with the travel of the oncoming vehicle.

[0005] The problem to be solved by the present invention is to provide a driving control method and a driving control device that can prevent the host vehicle from interfering with the travel of an oncoming vehicle when the oncoming vehicle is recognized in a scenario where the host vehicle changes lanes to the oncoming lane following a preceding vehicle and overtakes a plurality of obstacles on its own lane.

Means for Solving the Problems

[0006] The present invention solves the above problem by having the vehicle change lanes to the oncoming lane when avoiding a first obstacle in its own lane, determining whether there is a safe zone between the first and second obstacles where the vehicle can move to avoid a first obstacle in its own lane, recognizing an oncoming vehicle traveling in the oncoming lane after the preceding vehicle has started to change lanes from the oncoming lane to its own lane, and if there is a safe zone and there is a possibility that the vehicle will approach the oncoming vehicle while the vehicle is traveling in the oncoming lane, moving the vehicle into the safe zone. [Effects of the Invention]

[0007] According to the present invention, when a vehicle changes lanes into the oncoming lane following a preceding vehicle and overtakes multiple obstacles in its own lane, it is possible to prevent the vehicle from obstructing the oncoming vehicle's path when an oncoming vehicle is detected. [Brief explanation of the drawing]

[0008] [Figure 1] This is a block diagram showing a driving control system including a driving control device according to the present invention. [Figure 2] This is a plan view showing an example of a scenario in which the driving control method according to this embodiment is implemented. [Figure 3] This is a plan view showing an example of a driving scene in which the evacuation control in this embodiment is performed. [Figure 4] This is a plan view showing an example of a driving scene in which deceleration control is performed in this embodiment. [Figure 5] This is a flowchart illustrating an example of the procedure for the driving control method in this embodiment. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described below with reference to the drawings. The following description assumes that vehicles travel on the left side of the road in countries with left-hand traffic regulations. In countries with right-hand traffic regulations, vehicles travel on the right side of the road, so the terms "left" and "right" in the following description should be interpreted symmetrically.

[0010] Figure 1 is a block diagram illustrating the driving control system according to the present invention. The driving control system 10 is an in-vehicle system that drives the vehicle to a destination set by the vehicle's occupants (including the driver) through autonomous driving control. Autonomous driving control means autonomously controlling the vehicle's driving actions using the driving control device 6, and these driving actions include all driving actions such as acceleration, deceleration, starting, stopping, steering to the right or left, lane changes, and swerving. Furthermore, autonomously controlling driving actions means that the driving control device 6 controls the driving actions using the vehicle's devices. In other words, the driving control device 6 intervenes in and controls these driving actions within a predetermined range. For driving actions that are not intervened in, the driver performs manual operation.

[0011] As shown in Figure 1, the driving control system 10 includes a detection device 1, a map DB 2, a vehicle information detection device 3, a navigation device 4, a vehicle control device 5, and a driving control device 6. The detection device 1 includes an imaging device 11 and a distance measuring device 12. The vehicle information detection device 3 includes a vehicle speed detection device 31, a steering angle detection device 32, and a vehicle position detection device 33. The vehicle control device 5 includes a vehicle speed control device 51 and a steering control device 52. The devices included in the driving control system 10 are connected by CAN or other in-vehicle LAN and can exchange information with each other.

[0012] The driving control system 10 according to the present invention can be applied not only to the driving of a vehicle under autonomous driving control, but also to assisting the driving of a vehicle under manual driving by a driver. Furthermore, when the driving control system 10 is applied to the autonomous driving control of a vehicle, it can be applied not only to the autonomous control of both speed control and steering control, but also to the case where one of the speed control or steering control is autonomously controlled and the other is manually controlled.

[0013] Detection device 1 is a sensor for detecting the driving environment around the vehicle. The driving environment around the vehicle includes objects around the vehicle. These objects include, for example, road lane boundaries, zebra zone traffic guides, center lines, road signs, median strips, guardrails, curbs, highway side walls, road signs, traffic lights, pedestrian crossings, construction sites, accident sites, and traffic restrictions. Objects also include other vehicles, motorcycles, bicycles, and pedestrians. Objects also include obstacles that may affect the vehicle's movement. Detection device 1 acquires the position, orientation (direction), and speed of the detected objects. In this embodiment, detection device 1 detects the position of obstacles in the vehicle's lane, the position and speed of the preceding vehicle, and the position and speed of the oncoming vehicle.

[0014] The object is detected, for example, by the imaging device 11 and / or the rangefinder 12. The detection results from the imaging device 11 and the rangefinder 12 are acquired by the driving control device 6 at predetermined time intervals. The imaging device 11 is a device that recognizes objects around the vehicle using images, and is such as a camera. Multiple imaging devices 11 may be installed on a single vehicle. The rangefinder 12 is a device for calculating the relative distance and relative speed between the vehicle and the object, and is such as a laser radar or LIDAR. Multiple rangefinders 12 may be installed on a single vehicle.

[0015] Map DB2 is a high-precision three-dimensional map that describes road structures, including road surface markings that indicate lanes and destinations. Map DB2 is a database containing information used for generating driving routes and / or driving control. Map DB2 includes two-dimensional and / or three-dimensional position information at each map coordinate, road information at each map coordinate, lane boundary information, road attribute information, lane uphill / downhill information, lane identification information, connecting lane information, facility information, and their attribute information. Road information includes information such as road width, radius of curvature, shoulder structures, road traffic regulations (speed limits, whether lane changes are permitted), road merging points, branching points, and locations where the number of lanes increases or decreases. Map DB2 is stored in a readable state on a recording medium provided in the driving control device 6, on-board device, or server device.

[0016] In addition, the map DB2 includes information on lane boundaries indicating the boundaries between the lane on which the host vehicle travels and other areas. The lane boundaries exist on the left and right sides respectively with respect to the traveling direction of the host vehicle. The form of the lane boundaries is not particularly limited, and examples include road markings and road structures. Examples of the lane boundaries of road markings include lane boundary lines and center lines. Examples of the roadway boundaries of road structures include median strips, guardrails, curbstones, tunnels, or sidewalls of expressways. Note that for locations where the lane boundaries cannot be clearly identified (for example, within intersections), the lane boundaries are preset in the map DB2. The preset lane boundaries are overhead roadway boundaries and are not actual road markings or road structures that exist.

[0017] The host vehicle information detection device 3 is a device that detects information regarding the state of the host vehicle. The state of the host vehicle includes the traveling speed, acceleration, steering angle, position, attitude, etc. of the host vehicle. The traveling speed and acceleration are detected using the vehicle speed detection device 31. The steering angle is detected using the steering angle detection device 32. The current position is calculated based on the information obtained from the host vehicle position detection device 33. The attitude is detected using an inertial measurement unit. The traveling control device 6 obtains the detection results of these devices via an in-vehicle LAN as necessary.

[0018] The vehicle speed detection device 31 is not particularly limited as long as it is a sensor that can detect the traveling speed of the vehicle, and a known one can be used. Similarly, the steering angle detection device 32 is not particularly limited as long as it is a sensor that can detect the steering angle of the vehicle. Alternatively, the traveling speed and steering angle of the host vehicle may be obtained from the vehicle control device 5. The host vehicle position detection device 33 is a positioning system including a GPS unit, etc., is not particularly limited, and a known one can be used.

[0019] The navigation device 4 is a device that calculates a driving route from the current position of the host vehicle detected by the host vehicle position detection device 33 of the host vehicle information detection device 3 to the destination set by the driver by referring to the map DB2. The calculated driving route is output to the driving control device 6. The driving route is linear with the road, direction (uphill / downhill), and lane on which the host vehicle travels being identified. The driving route includes information on the driving lane.

[0020] The vehicle control device 5 is an in-vehicle computer such as an electronic control unit (ECU), and electronically controls in-vehicle devices that regulate the driving of the vehicle. The vehicle control device 5 includes a vehicle speed control device 51 that controls the driving speed of the host vehicle, and a steering control device 52 that controls the steering operation of the host vehicle.

[0021] The vehicle speed control device 51 controls a driving device such as an electric motor and / or an internal combustion engine, which is a driving power source, and an automatic transmission. The vehicle speed control device 51 autonomously controls the driving speed of the vehicle based on a control signal input from the driving control device 6.

[0022] The steering control device 52 controls the steering device. Based on a control signal input from the driving control device 6, the steering control device 52 uses at least one of the detection results of the detection device 1, the map DB2, and the host vehicle information acquired by the host vehicle information detection device 3 to autonomously control the operation of the steering device so that the host vehicle travels while maintaining a predetermined lateral position (position in the left-right direction of the vehicle) with respect to the set target trajectory.

[0023] The driving control device 6 is a device that controls the driving of the host vehicle by controlling and coordinating the devices included in the driving control system 10. In the present embodiment, the driving control device 6 realizes an autonomous driving control function by the processor 7. The processor 7 is a computer including a ROM 72 in which a program is stored, a CPU 71 that is an operation circuit for functioning as the driving control device 6 by executing the program stored in the ROM 72, and a RAM 73 that functions as an accessible storage device.

[0024] The processor 7 has a driving control function that drives the vehicle to a set destination using autonomous driving control. The driving route acquisition unit 100 acquires the driving route from the vehicle to the destination from the navigation device 40. The vehicle control unit 106 controls the driving of the vehicle based on the acquired driving route. In addition, if a preceding vehicle is recognized, the vehicle control unit 106 performs preceding vehicle following control to follow the preceding vehicle.

[0025] Furthermore, in this embodiment, when the vehicle is traveling on a single-lane road following a preceding vehicle, the processor 7 performs avoidance control using the avoidance control function so that the vehicle avoids the obstacle by following the preceding vehicle when an obstacle is present in the vehicle's lane. An obstacle is an object that obstructs the vehicle's movement. In the avoidance control, the vehicle changes lanes to the oncoming lane adjacent to its own lane, travels alongside the obstacle in its own lane on the oncoming lane, overtakes the obstacle, then changes lanes back to its own lane and moves to a position on the far side of the overtaken obstacle's direction of travel.

[0026] Furthermore, in this embodiment, as shown in Figure 2, when the vehicle changes lanes to the oncoming lane following a preceding vehicle and overtakes multiple obstacles in its own lane, the processor 7 uses the evacuation control function to move the vehicle to an evacuation section between the multiple obstacles when an oncoming vehicle is recognized. Figure 2 is a diagram showing an example of a scene in which the driving control method according to this embodiment is executed. The road shown in Figure 2 is a road with one lane in each direction, and the vehicle traveling in its own lane L1 travels from left to right in the diagram, and the vehicle traveling in the oncoming lane L2 travels from right to left in the diagram. Figure 2 shows a scene in which, on a road with one lane in each direction, the vehicle Va is traveling along the driving trajectory AL on the oncoming lane L2 in order to overtake parked vehicles Vb and Vc following a preceding vehicle Vd, when the preceding vehicle Vd completes the evacuation control first and returns to its own lane L1. At this time, the vehicle Va recognizes the oncoming vehicle Ve, which was in the blind spot of the preceding vehicle Vd and therefore could not be detected while Vd was traveling in the oncoming lane L2. Then, if the conditions for executing the evacuation control described later are met, the vehicle Va moves to the evacuation section ES located between the parked vehicles Vb and Vc. This prevents the vehicle from obstructing the oncoming vehicle by suddenly decelerating in the oncoming lane.

[0027] The processor 7 according to this embodiment executes each function through the cooperation of software for realizing the above functions and the hardware described above. The processor 7 includes, as functional blocks, a driving path acquisition unit 100, a driving boundary acquisition unit 101, a surrounding recognition unit 102, an avoidance determination unit 103, an avoidance control unit 104, an evasive control unit 105, and a vehicle control unit 106.

[0028] The driving boundary acquisition unit 101 acquires lane information around its own vehicle. For example, the driving boundary acquisition unit 101 acquires lane information for the lane in which the vehicle is traveling. In addition, if there is an obstacle such as a parked vehicle in the vehicle's lane, the driving boundary acquisition unit 101 acquires lane information for the adjacent lane adjacent to the vehicle's lane. In the case of a road with one lane in each direction, the adjacent lane is the oncoming lane. The lane information includes the position of the lane and the length of the lane in the width direction. First, the driving boundary acquisition unit 101 acquires the road structure around the vehicle from the map DB2 based on the vehicle's position and orientation. For example, if there is an oncoming lane adjacent to the vehicle's lane, the driving boundary acquisition unit 101 acquires lane information including the lane boundary line of the oncoming lane from the map DB2. Alternatively, the driving boundary acquisition unit 101 may acquire lane information including the lane boundary line of the vehicle's lane and the lane boundary line of the adjacent oncoming lane from the image of the vehicle's surroundings captured by the imaging device 11.

[0029] The surrounding recognition unit 102 recognizes the driving environment around the vehicle based on the detection information detected by the detection device 1. The driving environment includes objects around the vehicle. The surrounding recognition unit 102 also acquires the position, orientation, and speed of the recognized surrounding objects.

[0030] In this embodiment, the surrounding recognition unit 102 recognizes obstacles that obstruct the vehicle's movement in its own lane based on the detection information detected by the detection device 1 and the lane information. For example, the surrounding recognition unit 102 recognizes objects that satisfy the conditions described later as obstacles in its own lane, based on the positions of the left and right boundary lines of its own lane, the length of its own lane in the width direction, and the position and state of objects included in the detection information, which are included in the lane information of its own lane. In this embodiment, the obstacles are assumed to be stationary objects such as parked vehicles, but are not limited to these, and moving objects may also be recognized as obstacles.

[0031] The conditions for determining the presence or absence of an obstacle are, for example, that the object exists in the direction of travel of the vehicle's lane and that the object is stationary. Alternatively, the conditions for determining the presence or absence of an obstacle may be that the following three conditions are met: The first condition is that the object exists in the direction of travel of the vehicle's lane and that the object is stationary; the second condition is that the object is located at least a predetermined distance to the left or right of the center of the vehicle's lane; and the third condition is that the length obtained by subtracting the width of the object from the width of the vehicle's lane is less than or equal to a predetermined length. The predetermined length is the width required for the vehicle to pass alongside the object within its lane.

[0032] The surrounding area recognition unit 102 recognizes an obstacle located in the vehicle's lane in the direction of travel as a first obstacle when the vehicle is traveling in its own lane. Furthermore, if there is an obstacle in the vehicle's lane further in the direction of travel than the first obstacle, the surrounding area recognition unit 102 recognizes that obstacle as a second obstacle. For example, if, after the first obstacle is recognized, the vehicle begins to change lanes to the oncoming lane to avoid the first obstacle, the detection range of the detection device 1 expands behind the first obstacle, allowing the surrounding area recognition unit 102 to recognize the second obstacle.

[0033] The surrounding area recognition unit 102 recognizes a preceding vehicle in the direction of travel of the vehicle itself, based on the detection information detected by the detection device 1. The surrounding area recognition unit 102 also recognizes an oncoming vehicle traveling in the oncoming lane, based on the detection information detected by the detection device 1. In this embodiment, when the vehicle is traveling in the oncoming lane following a preceding vehicle, the surrounding area recognition unit 102 recognizes the oncoming vehicle after the preceding vehicle begins to change lanes from the oncoming lane to the vehicle's lane. When the preceding vehicle is traveling in the oncoming lane in front of the vehicle's lane, the surrounding area recognition unit 102 cannot recognize the oncoming vehicle in the oncoming lane due to the blind spot created by the preceding vehicle. However, as the preceding vehicle changes lanes from the oncoming lane to the vehicle's lane, and the position of the preceding vehicle shifts away from the oncoming lane, the surrounding area recognition unit 102 becomes able to recognize the oncoming vehicle in the oncoming lane.

[0034] The avoidance determination unit 103 determines, based on the recognized driving environment, whether or not to change lanes to the oncoming lane adjacent to the vehicle's own lane to avoid the first obstacle in the vehicle's own lane. For example, if the avoidance determination unit 103 recognizes the first obstacle by the surrounding recognition unit 102, it determines whether or not to avoid the first obstacle based on the lane information acquired by the driving boundary acquisition unit 101. The avoidance determination unit 103 determines to avoid the first obstacle if there is an oncoming lane that the vehicle can travel in. In other words, in this embodiment, if it is possible to avoid the first obstacle by veering into the oncoming lane, it determines to avoid the first obstacle. Also, if there is no oncoming lane that the vehicle can travel in, the avoidance determination unit 103 determines not to avoid the first obstacle. In this case, the vehicle stops before the first obstacle. Then, for example, the vehicle's driving control switches to manual driving by the driver.

[0035] Furthermore, the avoidance determination unit 103 may determine whether or not to avoid the first obstacle based on the lane information and the detected information. For example, if there is an oncoming lane, the avoidance determination unit 103 determines, based on the detected information, whether or not there is an obstacle in the oncoming lane that would hinder avoidance control. Obstacles include, for example, parked vehicles or oncoming vehicles. If there is no obstacle in the oncoming lane, the avoidance determination unit 103 determines to avoid the obstacle in its own lane. If there is an obstacle in the oncoming lane, the avoidance determination unit 103 determines not to avoid the obstacle in its own lane.

[0036] Furthermore, in this embodiment, if, after changing lanes to avoid the first obstacle, the avoidance determination unit 103 detects a new obstacle on its own lane, different from the first obstacle, for example, a second obstacle located further in the direction of travel than the first obstacle, the surrounding recognition unit 102 will determine whether or not to avoid the newly detected second obstacle. The method for determining whether or not to avoid the second obstacle is the same as the method for determining whether or not to avoid the first obstacle.

[0037] If the avoidance control unit 104 determines that the first obstacle should be avoided by the avoidance determination unit 103, it executes avoidance control to avoid the first obstacle. The avoidance control unit 104 generates an avoidance plan to avoid the first obstacle according to the driving environment around the vehicle and the determination result based thereon. The avoidance plan includes a driving trajectory to avoid the first obstacle. The avoidance control unit 104 generates a driving trajectory that changes lanes from the vehicle's lane to the oncoming lane, passes to the side of the first obstacle, and returns to the vehicle's lane. The driving trajectory is generated so as to minimize the vehicle's travel distance while not exceeding the vehicle's maximum steering angle, maximum lateral acceleration, maximum yaw rate, and maximum steering speed. The position where the vehicle passes to the side of the first obstacle is set to a position where the vehicle does not come into contact with the first obstacle and can reliably avoid the first obstacle. Once the driving trajectory is generated, the avoidance control unit 104 calculates a target steering angle and a target vehicle speed for the vehicle to travel along the driving trajectory.

[0038] Furthermore, when the vehicle initiates evasive control and changes lanes to the oncoming lane, the position of the vehicle and the first obstacle in the road width direction shifts, allowing the vehicle to recognize the driving environment further in the direction of travel than the first obstacle. If the vehicle changes lanes to the oncoming lane, and the surrounding recognition unit 102 recognizes the second obstacle, the evasive control unit 104 generates an evasive plan to avoid the second obstacle following the first obstacle and updates the evasive plan. That is, the evasive control unit 104 continues driving in the oncoming lane, passes the side of the second obstacle, and then generates a new driving trajectory to return from the oncoming lane to the vehicle's own lane. In this embodiment, if there are multiple obstacles in the vehicle's lane, a new evasive plan to avoid each recognized obstacle is generated at the time each obstacle is recognized, and evasive control of the vehicle is executed based on the generated evasive plan.

[0039] The evacuation control unit 105 executes evacuation control to move the vehicle back into its own lane when the vehicle is traveling in the oncoming lane. Evacuation control is a control that temporarily moves the vehicle back into its own lane from the oncoming lane to avoid the oncoming vehicle. By executing the evacuation control of the vehicle, the oncoming vehicle can continue traveling in the oncoming lane. After the oncoming vehicle has passed the side of the vehicle, the vehicle resumes avoidance control. For example, if there is a second obstacle in the vehicle's lane that is located further in the direction of travel of the vehicle than a first obstacle, the evacuation control unit 105 will move the vehicle into the evacuation section between the first and second obstacles if there is an evacuation section where the vehicle can evacuate, and there is a possibility that the vehicle will approach the oncoming vehicle.

[0040] First, when the surrounding recognition unit 102 recognizes a second obstacle, the evacuation control unit 105 determines whether or not there is an evacuation section between the first obstacle and the second obstacle. The evacuation section is a section defined by the distance required for the vehicle to move between the first and second obstacles. Based on the vehicle's own information and the detected information of the surrounding driving environment, the evacuation control unit 105 calculates the distance required for evacuation as the evacuation section distance, and determines that there is an evacuation section between the first and second obstacles if the distance between the first and second obstacles is equal to or greater than the evacuation section distance. If the distance between the first and second obstacles is less than the evacuation section distance, the evacuation control unit 105 determines that there is no evacuation section between the first and second obstacles. The distance between the first and second obstacles is the distance from the leading edge of the first obstacle to the rear end of the second obstacle.

[0041] The evacuation zone distance is the distance required for the vehicle to change lanes from the oncoming lane to its own lane, move into the evacuation zone, and then change lanes back to the oncoming lane after the oncoming vehicle has passed. For example, it is a distance set so that the steering control for changing lanes does not result in sudden steering that would impair the comfort of the occupants. This is because if the distance required for the vehicle to move into the evacuation zone while avoiding the first and second obstacles cannot be secured between the obstacles, the vehicle V1 cannot move into the evacuation zone.

[0042] Here, an example of how to calculate the distance of the escape section will be explained using Figure 3. Figure 3 is a diagram showing the scene in which escape control is performed in this embodiment. The road shown in Figure 3 is a one-lane road in each direction, similar to Figure 2, and vehicles traveling in their own lane L1 travel from left to right in the diagram, while vehicles traveling in the oncoming lane L2 travel from right to left in the diagram. In Figure 3, the vehicle Va changes lanes from its own lane L1 to the oncoming lane L2 in order to avoid an obstacle on its own lane L1. In the driving scene shown in Figure 3, a parked vehicle Vb is parked in the vehicle's own lane L1, and another parked vehicle Vc is parked behind the parked vehicle Vb in the direction of travel. Therefore, after avoiding the parked vehicle Vb, the vehicle Va continues to drive in the oncoming lane in order to overtake the parked vehicle Vc. The escape control unit 105 determines whether or not there is an escape section ES between the parked vehicle Vb and the parked vehicle Vc on its own lane L1.

[0043] In Figure 3, the evacuation section distance is the distance starting from the rear end of the parked vehicle Vc, and is the sum of the first distance D1 and the second distance D2. The first distance D1 is the distance from the rear end of the parked vehicle Vc to the front of the vehicle in the direction of travel. The first distance D1 is a predetermined distance, for example, the distance required for the vehicle, which has stopped in the evacuation section ES, to avoid the parked vehicle Vc by steering control and change lanes from its own lane L1 to the oncoming lane L2. When the vehicle Va moves into the evacuation section ES and stops, the vehicle Va is stopped so that the position of the rear axle of the vehicle Va is at a distance of the first distance D1 from the rear end of the parked vehicle Vc.

[0044] Furthermore, the second distance D2 is the distance required for the vehicle Va to move into the escape section ES while avoiding the parked vehicle Vb. The second distance D2 is calculated as follows. First, in Figure 3, the driving trajectory TL is the trajectory for the vehicle to escape between the parked vehicle Vb and the parked vehicle Vc. The vehicle Va turns left from the lane centerline of the opposing lane L2, passes the lane boundary line between the vehicle's lane L1 and the opposing lane L2, and then turns right to reach the lane centerline of the vehicle's lane L1. That is, the driving trajectory TL consists of a curve when turning left and a curve when turning right. The escape control unit 105 calculates the curvature ρ of the curve when turning using the following equation (1) based on the vehicle speed v and maximum lateral acceleration Ay of the vehicle Va. In this embodiment, the curve when turning right and the curve when turning left have the same curvature.

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[0045] Furthermore, if the evacuation control unit 105 determines that there is an evacuation section, it determines whether or not to perform evacuation control before the vehicle reaches the starting position of the evacuation section. The starting position of the evacuation section is a position located at a distance equal to the sum of the first distance and the second distance from the rear end of the second obstacle. In this embodiment, if the evacuation control unit 105 detects an oncoming vehicle by the surrounding recognition unit 102, it determines whether or not the vehicle may approach the oncoming vehicle, and determines to perform evacuation control if there is a possibility that the vehicle may approach the oncoming vehicle. If there is no possibility that the vehicle may approach the oncoming vehicle, the evacuation control unit 105 determines not to perform evacuation control.

[0046] For example, the evasion control unit 105 calculates the time to collision (TTC) between its own vehicle and the oncoming vehicle, and the time to complete evasion control by its own vehicle, and compares the collision time with the time to complete evasion control. If the collision time is less than or equal to the time to complete evasion control, the evasion control unit 105 decides to execute evasion control. If the collision time is greater than the time to complete evasion control, the evasion control unit 105 decides not to execute evasion control.

[0047] Here, the calculation methods for collision time and avoidance completion time are explained. The evasion control unit 105 acquires the relative distance between the vehicle and the oncoming vehicle, the vehicle speed of the vehicle, and the vehicle speed of the oncoming vehicle, and calculates the collision time until the vehicle and the oncoming vehicle collide based on the acquired relative distance, vehicle speed, and vehicle speed. The collision time is the value obtained by dividing the relative distance between the vehicle and the oncoming vehicle by the sum of the vehicle speed and the vehicle speed of the vehicle. The evasion control unit 105 also acquires the vehicle speed of the vehicle and the distance from the vehicle's current position to the avoidance completion position, and calculates the vehicle's avoidance completion time based on the vehicle speed and the distance from the vehicle's current position to the avoidance completion position. The avoidance completion position is the position where the driving trajectory for avoidance control intersects with the lane boundary line between the vehicle's lane and the oncoming lane. The avoidance completion time is the value obtained by dividing the distance from the vehicle's current position to the avoidance completion position by the vehicle's speed.

[0048] If the evacuation control unit 105 determines that evacuation control should be performed, it moves the vehicle into the evacuation zone and stops it. For example, the evacuation control unit 105 stops the vehicle so that the position of the vehicle's rear axle is at a position 1 distance away from the second obstacle in the direction of travel. The evacuation control unit 105 generates a travel trajectory for moving the vehicle into the evacuation zone and stopping it, and sets a target steering angle and target vehicle speed for traveling along the said travel trajectory. Furthermore, if the vehicle can avoid an oncoming vehicle, it does not need to stop in the evacuation zone. In other words, the vehicle may pass through the evacuation zone at a slow speed.

[0049] Furthermore, in this embodiment, the evacuation control unit 105 may also perform deceleration control when determining whether or not to perform evacuation control. That is, if there is an evacuation section, the evacuation control unit 105 performs deceleration control of the vehicle to increase the gap between the vehicle and the preceding vehicle before the vehicle reaches the starting position of the evacuation section. This delays the timing at which the vehicle reaches the starting position of the evacuation section, increasing the likelihood that the preceding vehicle will complete evasive control before the vehicle reaches the starting position of the evacuation section.

[0050] Here, using Figure 4, an example of a method for calculating the deceleration degree for executing deceleration control will be explained. Figure 4 is a diagram showing a scene in which evasive control is executed in this embodiment. The road shown in Figure 4 is a one-lane road in each direction, similar to Figure 2. Vehicles traveling in their own lane L1 travel from left to right in the diagram, and vehicles traveling in the oncoming lane L2 travel from right to left in the diagram. In Figure 4, the own vehicle Va and the preceding vehicle Vd are traveling in the oncoming lane L2 along the travel trajectory AL for evasive control in order to avoid an obstacle in their own lane L1. Also, an oncoming vehicle Ve is traveling in the oncoming lane L2. In the driving scene shown in Figure 4, a parked vehicle Vb is parked in the own lane L1, and a parked vehicle Vc is parked behind the parked vehicle Vb in the direction of travel. Therefore, in order to avoid the parked vehicles Vb and Vc on the own lane L1, the own vehicle Va is traveling in the oncoming lane L2 following the preceding vehicle Vd.

[0051] The evasion control unit 105 obtains the vehicle speed v1 of the preceding vehicle Vd and the third distance D3 from the position P2 of the preceding vehicle Vd to the evasion completion position P1, and calculates the evasion completion time t1 at which the preceding vehicle completes evasion control using the following equation (5) based on the vehicle speed v1 of the preceding vehicle Vd and the third distance D3.

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[0052] The evacuation control unit 105 does not perform evacuation control if there is no evacuation section. In this case, avoidance control by the evasive control unit 104 continues. That is, the avoidance control unit 104 performs avoidance control so that the vehicle changes lanes from the oncoming lane to its own lane after avoiding the first and second obstacles. Also, the evacuation control unit 105 does not perform evacuation control if it is not determined that evacuation control should be performed before the vehicle reaches the start position of the evacuation section. In this case as well, avoidance control by the avoidance control unit 104 continues. Furthermore, the evacuation control unit 105 does not perform deceleration control if there is no evacuation section. In this case as well, avoidance control by the avoidance control unit 104 continues.

[0053] The vehicle control unit 106 generates a control signal to drive the vehicle based on a target steering angle and target vehicle speed for controlling the vehicle's movement. The generated control signal is output to the vehicle control device 5. The vehicle control unit 106 sets a target steering angle and target vehicle speed for the vehicle's movement based on the travel path and outputs a control signal including the target steering angle and target vehicle speed to the vehicle control device 5. In this embodiment, if the target steering angle and target vehicle speed are set by the avoidance control unit 104 or the evasive control unit 105, the vehicle control unit 106 generates a control signal to drive the vehicle based on the set target steering angle and target vehicle speed.

[0054] Next, with reference to Figure 5, the procedure by which the driving control device 6 performs driving control will be described. Figure 5 is an example of a flowchart showing the procedure of the driving control method according to this embodiment. In this embodiment, if avoidance control cannot be started and the control flow ends, the driving control switches to manual driving by the driver.

[0055] In step S1, the processor 7 acquires lane information around its own vehicle. For example, the processor 7 acquires lane information for its own lane and the oncoming lane. In step S2, the processor 7 acquires detection information that detects the driving environment around its own vehicle. For example, the processor 7 acquires detection information of objects located around its own vehicle from the detection device 1. In step S3, the processor 7 recognizes a first obstacle that obstructs the vehicle's movement in its own lane, based on the lane information and detection information. In step S4, the processor 7 determines whether or not to avoid the first obstacle. If it determines to avoid the first obstacle, the processor 7 proceeds to step S5. If it determines not to avoid the first obstacle, the processor 7 terminates the control flow.

[0056] In step S5, the processor 7 generates a driving trajectory to avoid the first obstacle. The driving trajectory involves changing lanes to the oncoming lane, passing the side of the first obstacle in the oncoming lane, and then returning to the vehicle's own lane. In step S6, the processor 7 causes the vehicle to change lanes from its own lane to the oncoming lane along the driving trajectory. In step S7, the processor 7 recognizes a second obstacle. For example, based on lane information around the vehicle and detection information around the vehicle, the processor 7 recognizes a second obstacle located further in the direction of travel than the first obstacle in the vehicle's own lane. For example, the second obstacle is recognized after the vehicle has changed lanes to the oncoming lane. In this embodiment, if a second obstacle is recognized, the processor 7 generates a driving trajectory to avoid the second obstacle by continuing to drive the vehicle in the oncoming lane.

[0057] In step S8, the processor 7 calculates the distance of the escape section required for the vehicle to move between the first obstacle and the second obstacle. In step S9, the processor 7 determines whether or not there is an escape section between the first obstacle and the second obstacle. For example, the processor 7 obtains the distance between the first obstacle and the second obstacle, and determines that there is an escape section between the first obstacle and the second obstacle if the distance between the first obstacle and the second obstacle is greater than or equal to the escape section distance calculated in step S8. If it is determined that there is an escape section, the processor 7 proceeds to step S10. If it is determined that there is no escape section, the processor 7 proceeds to step S15.

[0058] In step S10, the processor 7 performs deceleration control of the vehicle to increase the distance between the vehicle and the preceding vehicle. For example, the processor 7 calculates the deceleration so that the preceding vehicle completes its avoidance maneuver before the vehicle reaches the start of the evasion section, and decelerates the vehicle based on the calculated deceleration. In step S11, the processor 7 recognizes an oncoming vehicle traveling in the opposite lane. In this embodiment, for example, the oncoming vehicle is recognized at the moment when the preceding vehicle completes its avoidance control and returns to its own lane. In step S12, the processor 7 determines whether there is a possibility that the vehicle will approach the oncoming vehicle. For example, the processor 7 calculates the time to collision (TTC) between the vehicle and the oncoming vehicle recognized in step S11, and the time to complete the avoidance control of the vehicle. If the time to collision is less than or equal to the time to complete the avoidance, the processor 7 determines that there is a possibility that the vehicle will approach the oncoming vehicle.

[0059] If the processor 7 determines that there is a possibility of the vehicle approaching an oncoming vehicle, it proceeds to step S13. If the processor 7 determines that there is no possibility of the vehicle approaching an oncoming vehicle, it proceeds to step S15. In step S13, the processor 7 performs evasive control for the vehicle. For example, the processor 7 moves the vehicle into the evasive zone and stops it. In step S14, the processor 7 resumes evasive control after the vehicle has stopped in the evasive zone and the oncoming vehicle has passed to the side of the vehicle. The processor 7 changes the vehicle's lane again from its own lane to the oncoming lane to avoid the second obstacle.

[0060] In step S15, the processor 7 determines whether or not the avoidance control has ended. The processor 7 determines that the avoidance control has ended if the vehicle has moved to a position further in the direction of travel than the second obstacle in its lane. If it determines that the avoidance control has ended, the processor 7 terminates the control flow. If it determines that the avoidance control has not ended, the processor 7 returns to step S15 and repeats the control flow thereafter.

[0061] As described above, this embodiment is a driving control method executed by a processor that performs autonomous driving control of the vehicle so that the vehicle changes lanes to the oncoming lane adjacent to the lane in which the vehicle is traveling, following a preceding vehicle, in order to avoid obstacles in the lane. The processor determines whether or not to avoid a first obstacle that obstructs the vehicle's movement in its lane. If it determines that the first obstacle should be avoided, it causes the vehicle to change lanes to the oncoming lane. If there is a second obstacle located further in the direction of travel of the vehicle than the first obstacle in the lane, the processor determines whether or not there is a retreat section between the first and second obstacles for the vehicle to move into. After the preceding vehicle has started to change lanes from the oncoming lane to the vehicle's lane, the processor recognizes an oncoming vehicle traveling in the oncoming lane. If there is a retreat section and there is a possibility that the vehicle will approach the oncoming vehicle while the vehicle is traveling in the oncoming lane, the processor moves the vehicle into the retreat section. This prevents the vehicle from obstructing the oncoming vehicle's path when it detects an oncoming vehicle while changing lanes into the oncoming lane following a preceding vehicle and overtaking multiple obstacles in its own lane.

[0062] Furthermore, in this embodiment, if there is a siding section, the processor performs deceleration control of the vehicle to increase the distance between the vehicle and the preceding vehicle before the vehicle reaches the start of the siding section. As a result, the preceding vehicle completes obstacle avoidance before the vehicle reaches the start of the siding section, allowing the vehicle to reliably confirm the presence or absence of oncoming vehicles.

[0063] Furthermore, in this embodiment, if there is a siding section, the processor determines whether there is a possibility that the vehicle may come into contact with an oncoming vehicle before reaching the starting position, and if there is a possibility that the vehicle may come into contact with an oncoming vehicle, it moves the vehicle into the siding section on its own lane. As a result, if there is a possibility that the vehicle may come into contact with an oncoming vehicle, the vehicle can start moving back into its own lane at the starting position of the siding section.

[0064] Furthermore, in this embodiment, the processor calculates the deceleration of the vehicle for executing deceleration control, and if the deceleration exceeds a predetermined maximum deceleration, it executes deceleration control based on the predetermined maximum deceleration. This ensures that deceleration control is performed without sudden deceleration, thereby ensuring passenger comfort.

[0065] Furthermore, in this embodiment, if there is no escape zone, the processor performs autonomous driving control so that the vehicle changes lanes from the oncoming lane back into its own lane after avoiding the first and second obstacles, without performing deceleration control. This prevents the vehicle from creating a gap with the preceding vehicle in a situation where it cannot return to its own lane, and reduces the possibility of approaching an oncoming vehicle.

[0066] The parked vehicles Vb and Vc shown in Figures 2-4 are examples of the "first obstacle" and "second obstacle" described in the claims, respectively.

[0067] The embodiments described above are provided to facilitate understanding of the present invention and are not intended to limit it. Therefore, each element disclosed in the above embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present invention. [Explanation of symbols]

[0068] 10… Driving control system 6… Driving control device 7…Processor 100...Route acquisition unit 101...Travel boundary acquisition unit 102... Surroundings Recognition Unit 103...Avoidance judgment section 104... Avoidance Control Unit 105... Evacuation Control Unit 106... Vehicle Control Unit

Claims

1. A driving control method, executed by a processor, which performs autonomous driving control of the vehicle so that the vehicle changes lanes to an oncoming lane adjacent to the lane in which the vehicle is traveling, following a preceding vehicle, and avoids obstacles in the lane, The aforementioned processor, The system determines whether or not to avoid the first obstacle that obstructs the movement of the vehicle in its own lane. If it is determined that the first obstacle should be avoided, the vehicle will change lanes to the oncoming lane. After the vehicle changes lanes to the oncoming lane, the vehicle recognizes a second obstacle located further in the direction of travel than the first obstacle in its own lane. If the second obstacle is detected in the vehicle's own lane, it is determined whether there is a section between the first obstacle and the second obstacle where the vehicle should move out. After the preceding vehicle begins to change lanes from the oncoming lane to its own lane, it recognizes an oncoming vehicle traveling in the oncoming lane, A driving control method that moves the vehicle to the designated siding when the vehicle is traveling in the oncoming lane, and there is a designated siding, and there is a possibility that the vehicle will come into close proximity with the oncoming vehicle.

2. The aforementioned processor, The driving control method according to claim 1, in the case where there is a siding section, the method executes deceleration control of the vehicle to increase the distance between the vehicle and the preceding vehicle before the vehicle reaches the starting position of the siding section.

3. The aforementioned processor, If there is a designated evacuation section, it is determined whether there is a possibility that the vehicle will come into close proximity with the oncoming vehicle before it reaches the starting position. The driving control method according to claim 2, wherein if there is a possibility that the vehicle may approach the oncoming vehicle, the vehicle moves to the siding section on the vehicle's lane.

4. The aforementioned processor, The deceleration of the vehicle itself is calculated in order to perform the aforementioned deceleration control, The driving control method according to claim 2 or 3, wherein if the deceleration is greater than or equal to a predetermined maximum deceleration, the deceleration control is performed based on the predetermined maximum deceleration.

5. The driving control method according to claim 2 or 3, wherein, if there is no escape section, the processor executes the autonomous driving control such that the vehicle changes lanes from the oncoming lane to its own lane after avoiding the first obstacle and the second obstacle, without executing the deceleration control.

6. A driving control device comprising a processor that performs autonomous driving control of the vehicle so that the vehicle changes lanes to an oncoming lane adjacent to the lane in which the vehicle is traveling, following a preceding vehicle, and avoids obstacles in the lane, The aforementioned processor, An avoidance determination unit that determines whether or not to avoid a first obstacle that obstructs the movement of the vehicle in its own lane, If it is determined that the first obstacle should be avoided, the avoidance control unit causes the vehicle to change lanes to the oncoming lane, An ambient recognition unit recognizes the driving environment around the vehicle based on detection information detected by a detection device, The system includes a control unit that moves the vehicle back into its own lane when the vehicle is traveling in the oncoming lane, The aforementioned surrounding recognition unit, After the avoidance control unit causes the vehicle to change lanes to the oncoming lane, it recognizes a second obstacle located further in the direction of travel of the vehicle than the first obstacle on the vehicle's lane, After the preceding vehicle begins to change lanes from the oncoming lane to its own lane, it recognizes an oncoming vehicle traveling in the oncoming lane, The aforementioned retraction control unit, If the surrounding area recognition unit recognizes the second obstacle on the vehicle's lane, it determines whether there is a section between the first obstacle and the second obstacle where the vehicle should move out. A driving control device that moves the vehicle into the aforementioned escape section if there is an escape section and the vehicle is likely to approach the oncoming vehicle.

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