Control device of vehicle

1. A control device of a vehicle, the control device comprising:

a deceleration control unit that performs a free running deceleration control that controls a free running deceleration that is a deceleration of a vehicle when transition occurs from an operation state in which an accelerator pedal or a brake pedal is operated to a non-operation state in which neither the accelerator pedal nor the brake pedal is operated;

an index deriving unit that derives a transition phase perceptual risk index that is a perceptual risk index when transition occurs from the operation state to the non-operation state in a case in which an index of a perceptual risk when an own vehicle approaches a preceding vehicle is the perceptual risk index; and

a relationship adjusting unit that adjusts a relationship between the perceptual risk index and the deceleration,

wherein in the relationship, when the perceptual risk index is equal to or less than a reference perceptual risk index, the deceleration is set to be equal to a lower limit deceleration, and when the perceptual risk index is larger than the reference perceptual risk index, the larger the perceptual risk index is, the larger the deceleration is set to be,

wherein in the free running deceleration control, the deceleration control unit derives the deceleration corresponding to the transition phase perceptual risk index based on the relationship and sets the derived deceleration as the free running deceleration, and

wherein the relationship adjusting unit executes a correction control in which when the transition phase perceptual risk index is larger than the reference perceptual risk index, the reference perceptual risk index is corrected to be increased, and when the transition phase perceptual risk index is smaller than the reference perceptual risk index, the reference perceptual risk index is corrected to be decreased.

2. The control device of a vehicle according to claim 1 , wherein:

in the relationship, when the perceptual risk index is equal to or larger than a predetermined perceptual risk index that is larger than the reference perceptual risk index, the deceleration is set to be equal to an upper limit deceleration, and when the perceptual risk index is larger than the reference perceptual risk index and smaller than the predetermined perceptual risk index, the larger the perceptual risk index is, the larger the deceleration is set to be; and

in the correction control, when the transition phase perceptual risk index is larger than the reference perceptual risk index, the relationship adjusting unit corrects the predetermined perceptual risk index to be increased, and when the transition phase perceptual risk index is smaller than the reference perceptual risk index, the relationship adjusting unit corrects the predetermined perceptual risk index to be decreased.

3. The control device of a vehicle according to claim 2 , wherein in the correction control, when the transition phase perceptual risk index is larger than the reference perceptual risk index, the larger a difference between the transition phase perceptual risk index and the reference perceptual risk index is, the larger an increasing correction amount of the reference perceptual risk index and an increasing correction amount of the predetermined perceptual risk index are set to be by the relationship adjusting unit, and when the transition phase perceptual risk index is smaller than the reference perceptual risk index, the larger the difference between the transition phase perceptual risk index and the reference perceptual risk index is, the larger a decreasing correction amount of the reference perceptual risk index and a decreasing correction amount of the predetermined perceptual risk index are set to be by the relationship adjusting unit.

4. The control device of a vehicle according to claim 3 , wherein in the correction control, when the transition phase perceptual risk index is larger than the reference perceptual risk index, the relationship adjusting unit sets the increasing correction amount of the reference perceptual risk index to be larger than the increasing correction amount of the predetermined perceptual risk index, and when the transition phase perceptual risk index is smaller than the reference perceptual risk index, the relationship adjusting unit sets the decreasing correction amount of the reference perceptual risk index to be larger than the decreasing correction amount of the predetermined perceptual risk index.

5. The control device of a vehicle according to claim 1 , wherein:

the perceptual risk index is derived based on a vehicle following distance between the own vehicle and the preceding vehicle, an approaching speed of the own vehicle toward the preceding vehicle, and a vehicle speed of the own vehicle; and

the index deriving unit derives the transition phase perceptual risk index based on the vehicle following distance, the approaching speed, and the vehicle speed of the own vehicle, when transition occurs from the operation state to the non-operation state.

6. The control device of a vehicle according to claim 1 , wherein:

the vehicle is an electric vehicle that has a generator that applies regenerative braking force corresponding to a power generation amount to the vehicle; and

in the free running deceleration control, the larger a target value of the free running deceleration control is, the larger the power generation amount of the generator is set to be by the deceleration control unit.