CROSS-REFERENCE TO RELATED APPLICATION

Priority is claimed on Japanese Patent Application No. 2017-168987, filed Sep. 1, 2017, the content of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a vehicle control system, a vehicle control method, and a storage medium.

Description of Related Art

A technology for supporting automatic lane change of a vehicle has been studied (see, for example, Japanese Unexamined Patent Application, First Publication No. 2014-133477). In this technology, the curvature of a lane in which the vehicle travels is recognized, and control is performed to give an offset to the steering of the vehicle according to the recognized curvature of the lane such that the vehicle travels along a target trajectory.

However, the technology of the related art does not take into consideration the external force applied to the vehicle in a case that performing steering control for lane change. Therefore, in the technology of the related art, the influence of the external force may disturb the behavior of the vehicle.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above circumstances and it is an object of the present invention to provide a vehicle control system, a vehicle control method, and a storage medium which can stabilize the behavior of a vehicle in a case that performing steering control for lane change or the like.

(1) A vehicle control system includes a first steering controller configured to execute first steering control for controlling a steering device such that a traveling lane is maintained, and a second steering controller configured to execute second steering control that is activated during execution of the first steering control, wherein the second steering controller is configured to execute, if a command value given to the steering device in the first steering control has continued to deviate either left or right in a case that the second steering control starts, the second steering control by reflecting the command value given in the first steering control.

(2) In the vehicle control system according to aspect (1), the second steering controller is configured to calculate, in a case that executing the second steering control, a correction command value on the basis of the command value given in the first steering control by the first steering controller and to add or subtract the correction command value to or from a command value for executing the second steering control.

(3) In the vehicle control system according to aspect (2), the second steering controller is configured to calculate the correction command value on the basis of a command value that has continued to be given in a case that traveling in a straight lane from among command values given in the first steering control excluding elements due to a curved road or a steering operation of an occupant.

(4) In the vehicle control system according to aspect (2), the second steering controller is configured to set a first target position at which the second steering control ends in a case that executing the second steering control and to set a second target position at which the second steering control ends to a position far from the first target position in a case that the calculated correction command value is equal to or greater than a predetermined threshold value.

(5) In the vehicle control system according to aspect (2), the second steering control of the second steering controller is control of performing lane change of a vehicle.

(6) A vehicle control method performed by a computer mounted in a vehicle includes the computer executing first steering control for controlling a steering device such that a traveling lane is maintained, and executing second steering control that is activated during execution of the first steering control, wherein if a command value given to the steering device in the first steering control has continued to deviate either left or right in a case that the second steering control starts, the second steering control is executed by reflecting the command value given in the first steering control.

(7) A computer-readable non-transitory storage medium storing a program causes a computer to execute first steering control for controlling a steering device such that a traveling lane is maintained and to execute second steering control that is activated during execution of the first steering control, wherein if a command value given to the steering device in the first steering control has continued to deviate either left or right in a case that the second steering control starts, the second steering control is executed by reflecting the command value given in the first steering control.

According to aspect (1), (6) or (7), it is possible to stabilize the behavior of the vehicle in a case that performing the second steering control that can be activated during execution of the first steering control.

According to aspect (2), it is possible to calculate the correction command value from the command value of the first steering control which has been executed before the second steering control and thus to stabilize the behavior of the vehicle in the second steering control in a state where an external force is applied to the vehicle.

According to aspect (3), it is possible to extract a specific value of the correction command value by excluding elements other than those of the external force applied to the vehicle in a case that calculating the correction command value.

According to aspect (4), by extending a distance over which the second steering control is performed, it is possible to further stabilize the behavior of the vehicle by the second steering control in a case that the influence of the external force is great.

According to aspect (5), it is possible to stably perform lane change of the vehicle.

