Steering device and method for controlling steering device
A steering device and a method for controlling the steering device according to the present invention are capable of suppressing, in a steer-by-wire steering device including a steering operation input member and a turning actuator that applies a turning force to a road wheel based on a driving signal, a change in which a yaw rate gain of a vehicle rises with respect to the operation speed of the steering operation input member by changing a turning angle command value to an angle less than the angle before the change when a turning frequency of the road wheel is a predetermined frequency. As a result, it becomes possible to suppress a case in which the yaw rate gain of the vehicle becomes too sensitive with respect to a steering operation by a driver.
1 . A steer-by-wire steering device to be mounted on a vehicle, the steer-by-wire steering device comprising:
a steering operation input member;
a turning actuator that applies a turning force to road wheels based on a driving signal; and
a control device that outputs the driving signal that causes a turning speed of the road wheels with respect to an operation speed of the steering operation input member to be slower when a yaw rate gain of the vehicle shows a change of rising with respect to the operation speed.
2 . The steering device according to claim 1 ,
wherein the control device includes:
a turning angle command unit that obtains a turning angle command value based on an operation angle of the steering operation input member;
a turning angle changing unit that acquires the turning angle command value, and changes and outputs the turning angle command value when a frequency of the turning angle command value is in a predetermined frequency range; and
a driving unit that outputs the driving signal to the turning actuator based on the turning angle command value output from the turning angle changing unit.
3 . The steering device according to claim 2 , wherein the turning angle changing unit executes filtering processing that attenuates a component of the turning angle command value in the predetermined frequency range.
4 . The steering device according to claim 3 , wherein the turning angle changing unit comprises a band-stop filter.
5 . The steering device according to claim 3 ,
wherein the control device includes
a steering gear ratio variable unit capable of varying a steering gear ratio that is a ratio of a turning angle of the road wheels to an operation angle of the steering operation input member in accordance with a vehicle speed of the vehicle; and
the turning angle command unit obtains the turning angle command value based on the operation angle of the steering operation input member and the steering gear ratio.
6 . The steering device according to claim 5 ,
wherein the steering gear ratio variable unit causes the steering gear ratio to be lower as the vehicle speed of the vehicle decreases.
7 . The steering device according to claim 3 ,
wherein the turning angle changing unit changes the turning angle command value based on the vehicle speed of the vehicle.
8 . The steering device according to claim 7 ,
wherein the turning angle changing unit causes an attenuation rate of the turning angle command value to decrease as the vehicle speed of the vehicle increases.
9 . The steering device according to claim 3 ,
wherein the turning angle changing unit changes the turning angle command value when the steering operation input member is operated from a state in which the steering operation input member is maintained at a freely selected operation angle.
10 . A method for controlling a steer-by-wire steering device to be mounted on a vehicle,
the steering device including:
a steering operation input member; and
a turning actuator that applies a turning force to a wheel,
the method for controlling comprising:
a step of obtaining the turning angle command value based on an operation angle of the steering operation input member;
a step of changing the turning angle command value when a frequency of the turning angle command value is in a predetermined frequency range; and
a step of controlling the turning actuator based on the turning angle command value after the change.