A controller controls a steering motor in accordance with a pinion angle command value calculated in response to a steering state. The steering motor produces a driving force to a steering operation mechanism. The controller calculates a target pinion angle in accordance with the steering state and the pinion angle command value by performing feedback control such that an actual pinion angle corresponds to the target pinion angle. The controller includes a compensation control circuit which calculates compensation amounts reflected in the pinion angle command value so as to compensate for an inertia component, a viscosity component, and a spring component of the steering operation mechanism in accordance with the target pinion angle. The compensation control circuit adds the compensation amounts to the target pinion angle so as to calculate the final target pinion angle to be used for the calculation of the pinion angle command value.

An electric power steering apparatus that drives a motor based a current command value and assist-controls a steering system by a driving-control of the motor. The apparatus includes a handle-returning control section that calculates a target steering angular velocity by using a steering angle, the vehicle speed, the steering torque and the current command value, calculates a handle-returning control current by using a limit-target steering angular velocity which is obtained by limiting the target steering angular velocity depending on steering angular velocity, and drives the motor by a compensated current command value which is obtained by adding the handle-returning control current to the current command value.

A steering control device includes an electronic control unit. The electronic control unit is configured to detect an absolute steering angle, to calculate a current command value, to control driving of a motor such that an actual current value which is supplied to the motor reaches the current command value, to store an end-position-corresponding angle which is correlated with the absolute steering angle, to perform end contact relaxation control for correcting the current command value such that a decrease of an end separation angle is regulated when the end separation angle is equal to or less than a predetermined angle, and to calculate the current command value such that an increase of the end separation angle is not regulated by the end contact relaxation control when the end separation angle is equal to or less than the predetermined angle.

A system and a method of controlling a motor-driven power steering are disclosed. A basic steering torque assist compensation is made according to a LOAM compensation logic under a steering condition such as steering of a steering wheel and holding of the steering wheel after steering, and an additional steering torque compensation is made to reduce the basic steering torque assist compensation amount when returning the steering wheel to the center or releasing the steering wheel in a restoring direction, thereby reducing steering effort felt by a driver when returning the steering wheel to the center or releasing the steering wheel in the restoring direction, and thus maintaining proper steering effort when a torque sensor of a high-performance vehicle fails.

A method is disclosure for operating a steer-by-wire vehicle steering system with a steering wheel in a shut-down state of the vehicle. According to one step of the method, after the vehicle has been shut down a procedure is carried out to monitor whether the steering wheel of the vehicle is being moved. If a movement of the steering wheel is ascertained and the movement exceeds a defined first limiting value, the movement of the steering wheel is damped by a damping unit of the steering system. If no movement of the steering wheel exceeding the first limiting value was ascertained for a defined time period, no further monitoring of a movement of the steering wheel and no further damping of the movement of the steering wheel are undertaken, so long as the vehicle is shut down. If, alternatively or additionally, a movement of the steering wheel exceeds a second limiting value, which is lower than the first limiting value, but does not exceed the first limiting value was ascertained within the defined time period and it is ascertained on the basis of an evaluation of the movement profile of the movement of the steering wheel that the movement was not caused by a user, likewise no further monitoring of a movement of the steering wheel and also no further damping of the movement of the steering wheel are undertaken, so long as the vehicle is shut down. Moreover, a steer-by-wire steering system for a vehicle is specified.

[Problem]

An object of the present invention to provide an electric power steering apparatus that has improved reliability in a handle-returning function, by actively and smoothly returning a handle to a neutral point in a running state which is returned to a straight running state by calculating a target steering angle velocity after removing disturbance components included in a steering torque and an assist current, and correcting a current command value by using a handle-returning control current.

[Means for Solving the Problem]

The present invention is the electric power steering apparatus that drives a motor based on the current command value and assist-controls a steering system by a driving-control of the motor, comprising: a handle-returning control section to calculate the target steering angle velocity for handle-returning based on the steering torque, the current command value, a vehicle speed, a steering angle, calculate the handle-returning control current based on a deviation between the steering angle velocity and the target steering angle velocity, and interpose a filter, which attenuates frequency components which are equal to or higher than a steering input or which are equal to or higher than a vehicle motion characteristic, in a calculation path of the target steering angle velocity, wherein the motor is driven by the corrected current command value by using the handle-returning control current.

A control device of a steering device, for a vehicle, which includes left and right steering mechanisms not mechanically coupled to each other, and which steers left and right steered wheels individually by driving force of steering actuators, includes: a steered angle determining unit that determines a target steered angle for each of the left and right steering mechanisms; and a steering command unit that generates drive signals corresponding to the target steered angles, and outputs the drive signals to each of the actuators. When an anomaly occurs in one of the left and right steering mechanisms, the steered angle determining unit sets the target steered angle for the steering mechanisms that is normal to be different from the target steered angle when both the left and right steering mechanisms are normal.

In a steering control apparatus, a reaction force torque command value is calculated so that a detection value of a torque sensor follows a target value obtained by adding at least a viscosity command value and a return command value to a steering torque command value, and an electric current that flows to a reaction force rotary electric machine is controlled based on the reaction force torque command value. Whether a steering state is a turning state or a returning state is determined by comparing a physical quantity corresponding to an output torque of a reaction force device and the detection value of the torque sensor. Characteristics of one or more of a reaction force amount operation, a viscosity amount operation, and a return amount operation are made differ between the turning state and the returning state.

A steering module for a vehicle has a steering input element and a sensor device, which includes at least one sensor, for registering the position of the steering input element, and has a servomechanism which includes a first actuator and acts on the steering input element. The servomechanism is redundantly designed and comprises a second actuator.

A steering control device which applies an assist torque or a reaction torque to a steering member operated by a driver, includes: a torque loss estimation unit which estimates torque loss; and a correction amount calculation unit which calculates a correction amount according to a rack axial force estimation value calculated based on a roll rate when the torque loss estimation unit estimates the torque loss.