Vehicle controller, method, and computer program for vehicle control

1 . A vehicle controller comprising:

a processor configured to:

detect a lane line defining a lane being traveled by a vehicle,

calculate a departure index indicating a possibility of the vehicle departing from the lane, based on a positional relationship between the lane line and the vehicle,

determine whether a predetermined departure condition is satisfied, based on the departure index,

upon determination that the departure condition is not satisfied, determine whether a driver of the vehicle has performed a departure prevention operation to prevent the vehicle from departing from the lane before the departure condition is satisfied,

upon determination that the driver has performed the departure prevention operation, modify the departure so as to relax the departure condition and reduce the amount of control of the vehicle upon execution of the departure prevention control,

upon determination that the departure condition is satisfied:

execute departure prevention control of the vehicle to prevent the vehicle departing from the lane, when the predetermined departure condition is satisfied,

determine whether the driver has performed an interruption operation to interrupt the departure prevention control during execution of the departure prevention control, and

upon determination that the driver has performed the interruption operation, modify the departure condition so as to tighten the departure condition and increase the amount of control of the vehicle upon execution of the departure prevention control.

2 . The vehicle controller according to claim 1 , wherein the processor tightens the predetermined departure condition and increases the amount of control of the vehicle upon execution of the departure prevention control, depending on an operation to interrupt the departure prevention control performed by the driver during execution of the departure prevention control.

3 . The vehicle controller according to claim 1 , wherein every time the operation to prevent the vehicle departing from the lane is performed, the processor increases, by a predetermined increment, a departure prevention count indicating the number of times the operation has been performed; and when a value of the departure prevention count exceeds a predetermined number, the processor relaxes the predetermined departure condition and reduces the amount of control of the vehicle upon execution of the departure prevention control.

4 . The vehicle controller according to claim 3 , wherein the processor modifies the predetermined increment, depending on the situation of the vehicle where the operation to prevent the vehicle departing from the lane is performed.

5 . A method for vehicle control, comprising:

detecting a lane line defining a lane being traveled by a vehicle;

calculating a departure index indicating a possibility of the vehicle departing from the lane, based on a positional relationship between the lane line and the vehicle;

determining whether a predetermined departure condition is satisfied, based on the departure index;

upon determination that the departure condition is not satisfied, determining whether a driver of the vehicle has performed a departure prevention operation to prevent the vehicle from departing from the lane before the departure condition is satisfied;

upon determination that the driver has performed the departure prevention operation, modifying the departure so as to relax the departure condition and reduce the amount of control of the vehicle upon execution of the departure prevention control;

upon determination that the departure condition is satisfied:

executing departure prevention control of the vehicle to prevent the vehicle departing from the lane, when the predetermined departure condition is satisfied;

determining whether the driver has performed an interruption operation to interrupt the departure prevention control during execution of the departure prevention control; and

upon determination that the driver has performed the interruption operation, modifying the departure condition so as to tighten the departure condition and increase the amount of control of the vehicle upon execution of the departure prevention control.

6 . A non-transitory recording medium that stores a computer program for vehicle control, the computer program causing a processor mounted on a vehicle to execute a process comprising:

detecting a lane line defining a lane being traveled by the vehicle;

calculating a departure index indicating a possibility of the vehicle departing from the lane, based on a positional relationship between the lane line and the vehicle;

determining whether a predetermined departure condition is satisfied, based on the departure index;

upon determination that the departure condition is not satisfied, determining whether a driver of the vehicle has performed a departure prevention operation to prevent the vehicle from departing from the lane before the departure condition is satisfied;

upon determination that the driver has performed the departure prevention operation, modifying the departure so as to relax the departure condition and reduce the amount of control of the vehicle upon execution of the departure prevention control;

upon determination that the departure condition is satisfied:

executing departure prevention control of the vehicle to prevent the vehicle departing from the lane, when the predetermined departure condition is satisfied;

determining whether the driver has performed an interruption operation to interrupt the departure prevention control during execution of the departure prevention control; and

upon determination that the driver has performed the interruption operation, modifying the departure condition so as to tighten the departure condition and increase the amount of control of the vehicle upon execution of the departure prevention control.