Vehicle driving assistance apparatus, vehicle driving assistance method, and computer-readable storage medium storing vehicle driving assistance program

1 . A vehicle driving assistance apparatus, comprising an electronic control unit which executes a deceleration assistance control of autonomously applying a braking force to an own vehicle to decelerate the own vehicle, and a coasting control of causing the own vehicle to coast,

wherein the electronic control unit is configured to:

execute the coasting control when a predetermined coasting condition becomes satisfied in a situation where the electronic control unit does not detect a deceleration target which creates a need to decelerate the own vehicle;

execute the deceleration assistance control when the electronic control unit detects the deceleration target in a situation where the predetermined coasting condition is not satisfied; and

determine whether to execute the coasting control depending on driving operation information on a driving operation carried out by an operator of the own vehicle when the electronic control unit detects the deceleration target in a situation where the predetermined coasting condition is satisfied.

2 . The vehicle driving assistance apparatus according to claim 1 , wherein the predetermined coasting condition is a condition that both an accelerator pedal and a brake pedal of the own vehicle are released.

3 . The vehicle driving assistance apparatus according to claim 1 , wherein the electronic control unit is configured to:

obtain a required deceleration rate of the own vehicle required at the point of time when the deceleration target is detected, based on the driver operation information when the deceleration target is detected in a situation where the predetermined coasting condition is satisfied; and

execute the coasting control when the required deceleration rate is equal to or less than a predetermined coasting deceleration rate.

4 . The vehicle driving assistance apparatus according to claim 3 , wherein the electronic control unit is configured to execute the deceleration assistance control when the required deceleration rate is equal to or greater than a predetermined braking deceleration rate that is greater than the predetermined coasting deceleration rate.

5 . The vehicle driving assistance apparatus according to claim 3 , wherein the electronic control unit is configured to determine that the required deceleration rate is equal to or less than the predetermined coasting deceleration rate when a driver of the own vehicle indicates a deceleration intention in a situation where a front inter-vehicle distance between the own vehicle and a preceding vehicle is shorter than a predetermined front inter-vehicle distance.

6 . The vehicle driving assistance apparatus according to claim 3 , wherein the electronic control unit is configured to determine that the required deceleration rate is equal to or less than the predetermined coasting deceleration rate when a following vehicle is located close to the own vehicle and the following vehicle is moving at a higher speed than the own vehicle.

7 . The vehicle driving assistance apparatus according to claim 1 , wherein the deceleration target is at least one of a preceding vehicle located in front of the own vehicle, a traffic light in front of the own vehicle in a moving direction of the own vehicle, a curved road in front of the own vehicle in the moving direction of the own vehicle, and a stop point in front of the own vehicle in the moving direction of the own vehicle.

8 . The vehicle driving assistance apparatus according to claim 1 , wherein the coasting control is a control of causing the own vehicle to coast by interrupting a transmission path of a driving force from a driving apparatus to driving wheels of the own vehicle.

9 . A vehicle driving assistance method for executing a deceleration assistance control of autonomously applying a braking force to an own vehicle to decelerate the own vehicle, and a coasting control of causing the own vehicle to coast,

wherein the vehicle driving assistance method comprises steps of:

executing the coasting control when a predetermined coasting condition becomes satisfied in a situation where a deceleration target which creates a need to decelerate the own vehicle, is not detected;

executing the deceleration assistance control when the deceleration target is detected in a situation where the predetermined coasting condition is not satisfied; and

determining whether to execute the coasting control depending on driving operation information on a driving operation carried out by an operator of the own vehicle when the deceleration target is detected in a situation where the predetermined coasting condition is satisfied.

10 . A non-transitory computer-readable storage medium storing a vehicle driving assistance program which executes a deceleration assistance control of autonomously applying a braking force to an own vehicle to decelerate the own vehicle and a coasting control of causing the own vehicle to coast,

wherein the vehicle driving assistance program is configured to:

execute the coasting control when a predetermined coasting condition becomes satisfied in a situation where a deceleration target which creates a need to decelerate the own vehicle, is not detected;

execute the deceleration assistance control when the deceleration target is detected in a situation where the predetermined coasting condition is not satisfied; and

determine whether to execute the coasting control depending on driving operation information on a driving operation carried out by an operator of the own vehicle when the deceleration target is detected in a situation where the predetermined coasting condition is satisfied.