Vehicle travel control device, method, and storage medium
A drive control device for controlling driving force of a vehicle includes a braking control device for applying braking force to a wheel, and a driving assistance ECU for controlling the drive control device to execute vehicle speed limit control for executing a driving force limit when the vehicle speed exceeds a limited vehicle speed. The driving assistance ECU is a vehicle travel control device for executing override control for releasing execution of the driving force limit until the vehicle speed becomes equal to or lower than the limited vehicle speed when the accelerator operation amount ACC is increased by a driver during execution of the vehicle speed limit control, and the driving assistance ECU controls the braking control device to decelerate the vehicle when the time when the accelerator operation amount is zero becomes equal to or longer than a reference time during execution of the override control.
1 . A vehicle travel control device comprising:
a drive electronic control unit (ECU) configured to output a signal to control a drive force of a vehicle according to at least an accelerator operation amount;
a braking ECU configured to output a signal to apply a braking force to wheels according to at least a braking operation amount to decelerate the vehicle; and
a driving assistance ECU configured to
start execution of vehicle speed limit control in response to a detection that a vehicle speed exceeds a limit vehicle speed, the vehicle speed limit control including causing the driving assistance ECU to control the drive force such that the vehicle speed does not exceed the limit vehicle speed,
start execution of override control for canceling limitation on the drive force in response to an operation by a driver in which the accelerator operation amount is equal to or greater than a predetermined operation value during execution of the vehicle speed limit control,
determine whether the accelerator operation amount is 0,
determine whether the braking operation amount is 0,
update an elapsed time after the accelerator operation amount becomes 0, in response to determination that the accelerator operation amount is 0 and the braking operation amount is 0 during the execution of the override control,
determine whether the elapsed time is equal to or longer than a reference time, and
decelerate the vehicle by causing the braking ECU to control the braking force in response to determination that the elapsed time is equal to or longer than the reference time.
2 . The vehicle travel control device according to claim 1 , wherein
the driving assistance ECU is further configured to compute, in a case where the determination is made that the elapsed time is equal to or longer than the reference time, a target deceleration of the vehicle so as to gradually increase from a deceleration of the vehicle at a time point when the elapsed time becomes equal to or longer than the reference time, and
the vehicle is decelerated by causing the braking ECU to control the braking force such that the deceleration of the vehicle becomes the target deceleration.
3 . The vehicle travel control device according to claim 1 , wherein the driving assistance ECU is further configured to compute a target deceleration of the vehicle so as to gradually increase to a maximum target deceleration set in advance.
4 . The vehicle travel control device according to claim 1 , wherein the driving assistance ECU is further configured to
determine whether the vehicle speed is lower than the limit vehicle speed after starting deceleration of the vehicle during the execution of the override control, and
terminate the execution of the override control in response to determination that the vehicle speed is lower than the limit vehicle speed after starting the deceleration of the vehicle during the execution of the override control.
5 . The vehicle travel control device according to claim 1 , wherein the reference time is set to be smaller when the vehicle speed is a first speed than when the vehicle speed is a second speed which is lower than the first speed.
6 . A vehicle drive control method to be applied to a vehicle,
the vehicle including
a drive control device that controls a drive force of the vehicle according to at least an accelerator operation amount, and
a braking control device that decelerates the vehicle by applying a braking force to wheels according to a braking operation amount, and
the method comprising:
starting execution of vehicle speed limit control in response to a detection that a vehicle speed exceeds a limit vehicle speed, the vehicle speed limit control including controlling the drive control device to limit the drive force such that the vehicle speed does not exceed the limit vehicle speed;
starting execution of override control for canceling limitation on the drive force in response to an operation by a driver in which the accelerator operation amount is equal to or greater than a predetermined operation value during execution of the vehicle speed limit control;
determining whether the accelerator operation amount is 0;
determining whether the braking operation amount is 0;
updating an elapsed time after the accelerator operation amount becomes 0, in response to determination that the accelerator operation amount is 0 and the braking operation amount is 0 during the execution of the override control;
determining whether the elapsed time is equal to or longer than a reference time; and
decelerating the vehicle by controlling the braking control device in response to determination that the elapsed time is equal to or longer than the reference time.