Steering device
A steering device turns a tire of a vehicle of a steer-by-wire system in which a steering mechanism and a turning mechanism are mechanically separated from each other and is provided with a turning device including a turning actuator and a turning angle control device. The turning actuator turns tires according to an instructed turning angle. The turning angle control device calculates a turning angle command value corresponding to an inputted steering angle signal and generates a signal driving the turning actuator based on that turning angle command value. The turning angle control device applies limit such that the absolute value of a turning angle velocity becomes equal to or below a turning angle velocity limit value set according to a predetermined parameter.
1 . A steering device configured to turn a tire of a vehicle of a steer-by-wire system, the steering device comprising:
a turning device including
a turning actuator configured to turn the tire according to an instructed turning angle and
a turning angle control device configured to calculate a turning angle command value, which corresponds to an inputted steering angle signal, and generate a signal to drive the turning actuator based on the turning angle command value, wherein
the turning angle control device is configured to
apply a limit, such that an absolute value of a turning angle velocity becomes equal to or below a turning angle velocity limit value, which is set according to a predetermined parameter, and
vary the turning angle velocity limit value according to a turning angle equivalent value,
wherein
the turning angle control device is configured to determine the turning and the returning based on a reaction force torque and a detection value of a torque sensor.
2 . The steering device according to claim 1 , wherein
the steering device is to be applied to a vehicle of a steer-by-wire system in which a driver performs driving operation,
the steering device further comprising:
a reaction force device including
a reaction force actuator configured to impart reaction force to a driver's steering operation of a steering, and
a reaction force control device configured to generate a signal, which is to drive the reaction force actuator, based on a signal from the turning angle control device.
3 . The steering device according to claim 1 , wherein
the turning angle control device is configured to reduce the turning angle velocity limit value with reduction in a remaining angle, which is an absolute value of a difference between a current turning angle or steering angle and a critical angle at a corresponding mechanical end, according to the remaining angle, such that an angle error, which is caused by turning angle velocity limit, becomes equal to a predetermined allowable angle error or below.
4 . The steering device according to claim 1 , wherein
the turning angle control device is configured to vary the turning angle velocity limit value according to a vehicle behavior.
5 . The steering device according to claim 1 , wherein
the turning angle control device is configured to vary the turning angle velocity limit value according to a vehicle speed.
6 . The steering device according to claim 1 , wherein
the turning angle control device is configured to vary a steering angle ratio, which is a ratio of a turning angle to a steering angle, according to a steering angle equivalent value or a turning angle equivalent value.
7 . The steering device according to claim 1 , wherein
the turning angle control device is configured to vary the turning angle velocity limit value in both the turning and the returning.
8 . The steering device according to claim 1 , wherein
the turning angle control device is configured to determine the turning and the returning based on the steering angle signal and the turning angle velocity.
9 . The steering device according to claim 1 , wherein
the turning angle control device is configured to determine the turning and the returning based on a steering torque and the turning angle velocity.
10 . A steering device configured to turn a tire of a vehicle of a steer-by-wire system, the steering device comprising:
a turning device including
a turning actuator configured to turn the tire according to an instructed turning angle and
a turning angle control device configured to calculate a turning angle command value, which corresponds to an inputted steering angle signal, and generate a signal to drive the turning actuator based on the turning angle command value, wherein
the turning angle control device is configured to
apply a limit, such that an absolute value of a turning angle velocity becomes equal to or below a turning angle velocity limit value, which is set according to a predetermined parameter, and
vary the turning angle velocity limit value according to a status of turning and returning, wherein
the turning angle velocity limit value for returning is smaller than the turning angle velocity limit value for turning.
11 . A steering device configured to turn a tire of a vehicle of a steer-by-wire system, the steering device comprising:
a turning device including
a turning actuator configured to turn the tire according to an instructed turning angle and
a turning angle control device configured to calculate a turning angle command value, which corresponds to an inputted steering angle signal, and generate a signal to drive the turning actuator based on the turning angle command value, wherein
the turning angle control device is configured to
apply a limit, such that an absolute value of a turning angle velocity becomes equal to or below a turning angle velocity limit value, which is set according to a predetermined parameter, and
vary the turning angle velocity limit value according to a turning angle equivalent value, wherein
the steering device is to be applied to a vehicle of a steer-by-wire system in which a driver performs driving operation,
the steering device further comprising:
a reaction force device including
a reaction force actuator configured to impart reaction force to a driver's steering operation of a steering, and
a reaction force control device configured to generate a signal, which is to drive the reaction force actuator, based on a signal from the turning angle control device,
wherein
the reaction force device is configured to i) switch a constant of the reaction force control device or ii) to match a constant of friction control and a constant of inertia control, such that the reaction force is increased, when the turning angle control device applies the limit to the turning angle velocity.