Vehicle control device

Abstract

To provide a vehicle control device that reliably and smoothly displaces a travel position of a vehicle in a lane width direction to a target position.SOLUTION: A vehicle control device performs steering control to steer a vehicle 2 to displace a travel position LP in a lane-width direction of the vehicle 2 from an initial travel position LP0 to a target travel position LPt in response to presence of an avoidance target 4 ahead. The steering control includes feedback control to make a front-rear axis of the vehicle 2 parallel to a lane travel direction. The feedback control is initiated when a lateral deviation of the travel position LP of the vehicle 2 from the target travel position LPt is less than a set value.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vehicle control device, and more particularly to a vehicle control device suitable for use in avoidance assistance. [Background technology]

[0002] Patent Document 1 discloses a device that generates additional steering torque when a driver performs an avoidance maneuver to increase the amount of lateral movement so that the vehicle does not collide with an obstacle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2019-533601 Summary of the Invention [Problem to be solved by the invention]

[0004] In the device disclosed in Patent Document 1, after it is determined that the target lateral movement amount has been achieved, a steering torque opposite to the avoidance steering torque is applied, which may cause the vehicle to move beyond the target lateral movement amount, resulting in the vehicle deviating from the lane.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a vehicle control device that reliably and smoothly displaces the vehicle's traveling position in the lane width direction to a target position. [Means for solving the problem]

[0006] The vehicle control device of the present invention is configured to execute steering control for steering the vehicle in response to the presence of an object to be avoided ahead so as to displace the vehicle's running position in the lane width direction to a target running position where a target avoidance amount is achieved. The steering control includes feedback control for making the front and rear axes of the vehicle parallel to the lane traveling direction. The feedback control is started in response to the lateral deviation of the running position of the vehicle from the target running position becoming equal to or smaller than a set value. Effect of the Invention

[0007] According to the vehicle control device of the present invention, feedback control in steering control is initiated when the lateral deviation of the vehicle's driving position from the target driving position falls below a set value, so that the vehicle's driving position in the lane width direction can be reliably and smoothly displaced to the target driving position while preventing the vehicle from overshooting the target driving position. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic diagram for explaining the operation of a vehicle whose steering is controlled by a vehicle control device according to an embodiment of the present invention; [Diagram 2] 4 is a flowchart showing a control flow of steering control by a vehicle control device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments of the present invention will be described with reference to the drawings. However, when the number, quantity, amount, range, etc. of each element is mentioned in the embodiments shown below, the present invention is not limited to the mentioned numbers unless otherwise specified or clearly specified in principle. Furthermore, the structures, steps, etc. described in the embodiments shown below are not necessarily essential to the present invention unless otherwise specified or clearly specified in principle.

[0010] A vehicle control device according to an embodiment of the present invention is mounted on a vehicle and assists the driver in driving the vehicle. Driving assistance provided to the vehicle control device includes avoidance assistance for avoiding obstacles. In the avoidance assistance, the vehicle control device controls the steering of the vehicle on behalf of the driver. FIG. 1 is a schematic diagram for explaining the operation of a vehicle 2 whose steering is controlled by a vehicle control device 10. Hereinafter, an overview of steering control for avoidance assistance by the vehicle control device 10 will be described with reference to FIG. 1.

[0011] The left-right direction in Fig. 1 corresponds to the lane width direction of the road on which the vehicle 2 travels, and the up-down direction in Fig. 1 corresponds to the lane travel direction. In the example shown in Fig. 1, the initial travel position of the vehicle 2, i.e., the travel position in the lane width direction, is LP0. Hereinafter, the initial travel position LP0 in the lane width direction is referred to as the initial travel position LP0.

[0012] 1, when a traveling vehicle 2 is at an initial traveling position LP0, the vehicle control device 10 detects an object to be avoided 4 in front of the vehicle 2. There is no limitation on the method of detecting the object to be avoided 4. For example, an object in the vicinity of the vehicle 2 may be detected by a surrounding monitoring sensor such as a camera or LIDAR mounted on the vehicle 2, and it may be determined whether or not the object detected in the vicinity of the vehicle 2 is an object to be avoided based on the size, position, and movement of the object.

[0013] Upon detection of an object to be avoided 4 ahead, the vehicle control device 10 moves the vehicle 2 in a direction away from the object to be avoided 4. Specifically, the amount of movement in the lane width direction required to avoid contact with the object to be avoided 4 is calculated as a target amount of avoidance, and a traveling position in the lane width direction at which the target amount of avoidance can be achieved is set as a target traveling position LPt. Then, steering control is executed to steer the vehicle 2 so as to displace the traveling position LP of the vehicle 2 in the lane width direction from an initial traveling position LP0 to the target traveling position LPt.

[0014] The vehicle control device 10 steers the vehicle 2 so as to move the vehicle 2 along the ideal driving trajectory TTi. The ideal driving trajectory TTi is a driving trajectory that can reliably and smoothly displace the driving position LP of the vehicle 2 to the target driving position LPt. In order to realize the ideal driving trajectory TTi, feedback control of the yaw angle of the vehicle 2 is required so that the front and rear axes of the vehicle 2 are parallel to the traveling direction of the lane when the vehicle 2 reaches the target driving position LPt. For this reason, the steering control for avoidance assistance executed by the vehicle control device 10 includes feedback control.

[0015] However, it is not enough to simply execute feedback control. If feedback control is started after the vehicle 2 reaches the target traveling position LPt, the vehicle 2 will overshoot the target traveling position LPt. Therefore, feedback control needs to be started before the vehicle 2 reaches the target traveling position LPt, but the control results obtained will differ depending on how the feedback control is executed.

[0016] For example, there is a concept of executing feedback control from the start of steering control. However, in this case, control that tries to make the front and rear axes of the vehicle 2 parallel to the lane traveling direction intervenes immediately after the start of steering control, so it is difficult to increase the amount of avoidance, and there is a risk that the vehicle 2 will not be able to avoid the avoidance target 4.

[0017] One approach is to start feedback control when a certain amount of time has elapsed since the start of steering control, or when the distance between the target to be avoided 4 and the vehicle 2 becomes equal to or less than a set value. However, if feedback control is started at these times, the steering control for avoidance may be hindered due to recognition errors in the timing of recognition of the target to be avoided 4 by the surrounding monitoring sensor of the vehicle 2 and in the recognition of the position.

[0018] There is also a concept that the closer the vehicle 2's driving position LP approaches the white line of the lane on the avoidance side, the larger the gain of the feedback control. However, in this case, depending on the distance between the target driving position LPt and the white line, there is a risk that the front and rear axes of the vehicle 2 cannot be made parallel to the traveling direction of the lane.

[0019] As described above, if the method of executing feedback control is not appropriate, the vehicle 2 cannot be moved along the ideal traveling trajectory TTi. Therefore, the vehicle control device 10 starts feedback control when the lateral deviation of the traveling position LP of the vehicle 2 from the target traveling position LPt becomes equal to or less than a set value. That is, in this embodiment, the timing of executing feedback control is determined based on the distance from the target traveling position LPt. Note that the set value may be a fixed value or may be a variable value set according to, for example, the vehicle speed.

[0020] 2 is a flowchart showing a control flow of steering control by the vehicle control device 10. After starting steering control, in step S1, the vehicle control device 10 calculates the lateral deviation of the traveling position LP with respect to the target traveling position LPt, and determines whether the lateral deviation is equal to or smaller than a set value.

[0021] If it is determined in step S1 that the lateral deviation is greater than the set value, step S3 is selected. In step S3, the vehicle control device 10 does not execute feedback control for making the front and rear axes of the vehicle 2 parallel to the lane travel direction. In other words, the vehicle control device 10 continues steering control without feedback control.

[0022] After step S3, step S4 is executed. In step S4, the vehicle control device 10 determines whether the vehicle 2 has reached the target traveling position LPt and the front and rear axes of the vehicle 2 are parallel to the traveling direction of the lane.

[0023] While feedback control is not being executed, the determination result in step S4 is negative. The control flow returns to step S1, and the vehicle control device 10 updates the lateral deviation of the traveling position LP with respect to the target traveling position LPt. Then, it is determined whether the updated lateral deviation is equal to or less than a set value. Steps S1, S3, and S4 are repeatedly executed by the vehicle control device 10 until the lateral deviation becomes equal to or less than the set value.

[0024] When the lateral deviation of the vehicle 2's traveling position LP from the target traveling position LPt becomes equal to or smaller than the set value, step S2 is selected. In step S2, the vehicle control device 10 executes feedback control to make the front and rear axes of the vehicle 2 parallel to the traveling direction of the lane.

[0025] After step S3, step S4 is executed. In step S4, the vehicle control device 10 determines whether the vehicle 2 has reached the target traveling position LPt and the front and rear axes of the vehicle 2 are parallel to the traveling direction of the lane.

[0026] Immediately after the feedback control starts, the condition of step S4 is not satisfied, and steps S1, S2, and S4 are repeatedly executed by the vehicle control device 10. During this time, the feedback control is executed by the vehicle control device 10, and the vehicle 2 approaches the target driving position LPt, while the front-rear axis of the vehicle 2 becomes parallel to the traveling direction of the lane. Eventually, when the vehicle 2 reaches the target driving position LPt and the front-rear axis of the vehicle 2 becomes parallel to the traveling direction of the lane, the steering control ends.

[0027] As described above, according to the vehicle control device 10, the feedback control is started in response to the lateral deviation of the traveling position LP of the vehicle 2 from the target traveling position LPt becoming equal to or less than the set value. This makes it possible to prevent the vehicle 2 from overshooting the target traveling position LPt. In addition, since the feedback control does not interfere with the steering control for avoidance, the traveling position LP of the vehicle 2 can be reliably and smoothly displaced to the target traveling position LPt. [Explanation of symbols]

[0028] 2 Vehicles 4. Avoidance Targets 10 Vehicle control device LP Lane width direction driving position LP0 Initial running position LPt Target travel position TTi Ideal driving trajectory

Claims

[Claim 1] The steering control is configured to execute a steering control for steering the vehicle in response to the presence of an avoidance target ahead of the vehicle so as to displace the vehicle's traveling position in a lane width direction to a target traveling position at which a target avoidance amount is achieved, the steering control includes a feedback control for making the front and rear axes of the vehicle parallel to the traveling direction of the lane; The feedback control is started when a lateral deviation of the traveling position with respect to the target traveling position becomes equal to or smaller than a set value. A vehicle control device comprising:

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