Vehicle movement control device, vehicle movement control method, and vehicle movement control program

1. A vehicle motion control device which controls a motion of a vehicle, comprising:

a target trajectory acquisition unit which acquires a target trajectory of the vehicle;

a lateral motion prediction unit which predicts a lateral motion of the vehicle based on the target trajectory; and

a YAW moment control unit which controls a YAW moment generated in the vehicle by a difference of braking/driving forces of right and left wheels of the vehicle according to the lateral motion of the vehicle,

wherein the YAW moment control unit controls the YAW moment generated in the vehicle in a first period predicted by the lateral motion prediction unit when the lateral motion of the vehicle is changed from a state where the vehicle exhibits one of right and left lateral motions to a state where the vehicle exhibits the other lateral motion, and

the YAW moment control unit sets an absolute value of deceleration generated in the vehicle in a second period predicted by the lateral motion prediction unit to be smaller than an absolute value of deceleration generated in the vehicle in the first period when the lateral motion of the vehicle is changed from a state where the vehicle exhibits the lateral motion to a state where the vehicle does not exhibit the lateral motion, wherein

the vehicle motion control device further includes a longitudinal acceleration control unit which controls a longitudinal acceleration of the vehicle according to the lateral motion generated in the vehicle, and

the longitudinal acceleration control unit controls the longitudinal acceleration operating on the vehicle in a third period in which an absolute value of lateral acceleration operating on the vehicle is increased and a degree of sideslip angle of the vehicle is less than a sideslip angle threshold, and

in a fourth period in which the absolute value of lateral acceleration operating on the vehicle is increased and the degree of the sideslip angle of the vehicle is equal to or more than the sideslip angle threshold, the longitudinal acceleration control unit sets an absolute value of longitudinal acceleration operating on the vehicle to be smaller than an absolute value of longitudinal acceleration generated in the vehicle in the third period.

2. The vehicle motion control device according to claim 1 ,

wherein the vehicle motion control device includes a sideslip acquisition unit which acquires the degree of the sideslip angle of the vehicle, and

the YAW moment control unit sets the YAW moment generated in the vehicle to be larger in a case where the degree of the sideslip angle of the vehicle is equal to or more than the sideslip angle threshold in the second period than that in a case where the degree of the sideslip angle of the vehicle is less than the sideslip angle threshold.

3. The vehicle motion control device according to claim 2 ,

wherein the YAW moment control unit calculates a target YAW rate of the vehicle on the basis of a steering angle of the vehicle and a speed of the vehicle, and

the sideslip acquisition unit determines a magnitude of the sideslip angle of the vehicle on the basis of at least one of a sideslip angle of the vehicle and a difference between the target YAW rate and an actual YAW rate generated in the vehicle.

4. The vehicle motion control device according to claim 1 ,

wherein the YAW moment control unit controls the YAW moment generated in the vehicle to suppress a YAW motion of the vehicle during a period predicted by the lateral motion prediction unit when the lateral motion of the vehicle is decreased.

5. The vehicle motion control device according to claim 1 ,

wherein, when a state where a lateral acceleration of one of the right and left sides of the vehicle operates is shifted to a state where the other lateral acceleration operates in the first period, the lateral motion prediction unit predicts that the lateral motion of the vehicle is changed from the state where the vehicle takes one of the right and left lateral motions to the state where the vehicle takes the other lateral motion, and

when a state where the lateral acceleration operates on the vehicle is shifted to a state where the lateral acceleration does not operate in the second period, the lateral motion prediction unit predicts that the lateral motion of the vehicle is changed from the state where the vehicle takes the lateral motion to the state where the vehicle does not take the lateral motion.

6. The vehicle motion control device according to claim 1 ,

wherein, when a state where a steering angle of the vehicle causes the vehicle to turn to one of right and left directions is shifted to a state where the vehicle is turned to the other direction in the first period, the lateral motion prediction unit predicts that the lateral motion of the vehicle is changed from the state where the vehicle takes one of the right and left lateral motions to the state where the vehicle takes the other lateral motion, and

when the state where the steering angle of the vehicle causes the vehicle to turn to one of the right and left directions is shifted to the state where the vehicle is not turned in the second period, the lateral motion prediction unit predicts that the lateral motion of the vehicle is changed from the state where the vehicle takes the lateral motion to the state where the vehicle does not take the lateral motion.

7. The vehicle motion control device according to claim 1 ,

wherein, in the second period, the longitudinal acceleration control unit sets an absolute value of longitudinal acceleration operating on the vehicle to be larger than an absolute value of longitudinal acceleration generated in the vehicle in the first period.

8. The vehicle motion control device according to claim 1 ,

wherein the vehicle motion control device includes a sideslip acquisition unit which acquires the degree of sideslip angle of the vehicle, and

the longitudinal acceleration control unit sets an absolute value of longitudinal acceleration generated in the vehicle to be smaller in a case where the degree of the sideslip angle of the vehicle is equal to or more than the sideslip angle threshold in the second period than that in a case where the degree of the sideslip angle of the vehicle is less than the sideslip angle threshold.

9. The vehicle motion control device according to claim 1 ,

wherein the target trajectory acquisition unit calculates the target trajectory on the basis of a steering angle of the vehicle or a steering angle of a tire, and a speed of the vehicle.

10. The vehicle motion control device according to claim 1 ,

wherein the target trajectory acquisition unit acquires the target trajectory from another control device of the vehicle.

11. A non-transitory computer-readable storage medium storing instructions, which when when executed by a vehicle motion control device execute a vehicle motion control program, which causes the vehicle motion control device to:

acquire a target trajectory of the vehicle;

predict a lateral motion of the vehicle on the basis of the target trajectory;

calculate a control command value to control a YAW moment generated in the vehicle by a difference of braking/driving forces of right and left wheels of the vehicle according to the lateral motion of the vehicle; and

transmit the control command value to an actuator which controls the YAW moment generated in the vehicle, wherein

in the calculating of the control command value, the vehicle motion control device calculates the control command value in a first period predicted in the predicting of the lateral motion when the lateral motion of the vehicle is changed from a state where the vehicle exhibits one of right and left lateral motions to a state where the vehicle exhibits the other lateral motion,

in the controlling of the YAW moment, the vehicle motion control device calculates the control command value so that an absolute value of deceleration generated in the vehicle in a second period predicted in the predicting of the lateral motion is set to be smaller than an absolute value of deceleration generated in the vehicle in the first period when the lateral motion of the vehicle is changed from a state where the vehicle exhibits the lateral motion to a state where the vehicle does not exhibit it the lateral motion,

the vehicle motion control device further includes a longitudinal acceleration control unit which controls a longitudinal acceleration of the vehicle according to the lateral motion generated in a vehicle, and

the longitudinal acceleration control unit controls the longitudinal acceleration operating on the vehicle in a third period in which an absolute value of lateral acceleration operating on the vehicle is increased and a degree of sideslip angle of the vehicle is less than sideslip angle threshold,

in a fourth period in which the absolute value of lateral acceleration operating on the vehicle is increased and a degree of the sideslip angle of the vehicle is equal to or more then sideslip angle threshold, the longitudinal acceleration control unit sets an absolute value of longitudinal acceleration operating on the vehicle to be smaller than an absolute value of longitudinal acceleration generated in the vehicle in the third period.