Abstract: Provided is a steer-by-wire steering system for a vehicle that can reduce or eliminate the impact noise generated by the rack at the rack end. A control unit of the steering system is configured to determine a target steered angle (?t) according to the steering angle and drive the steering actuator so as to cause the steered angle to coincide with the target steered angle, and to determine a target reaction force (Tt) according to a steered state of the wheels and drive the reaction force actuator so as to cause the reaction force to coincide with the target reaction force. The control unit is further configured to set a maximum limit (?mC) on the target steered angle, the maximum limit being a value smaller than a physical maximum steered angle (?mP) of the wheels imposed by the steering mechanism.

Abstract: A method to control a steer-by-wire steering system of a road vehicle including a steering wheel coupled to a steering shaft, a road wheel actuator to turn steerable road wheels, a shaft sensor to detect a rotation of the steering shaft and a controller configured or programmed to generate an operation signal for the road wheel actuator from a signal detected by the shaft sensor, includes determining a real steering wheel angle by the shaft sensor, modifying the real steering wheel angle by applying an artificial hysteresis to create an offset between the real steering wheel angle and a modified steering wheel angle to mimic a behavior of an electromechanical power steering mechanism, and generating the motor torque request for the road wheel actuator based on the modified steering wheel angle.

Abstract: A method to control a steer-by-wire steering system for a road vehicle including a steering device, a road wheel actuator to actuate road wheels, and a controller configured or programmed to generate a motor torque request for the road wheel actuator based on an actual or an estimated position and a position request, which is based on the position of the steering device, includes detecting a road wheel actuator power limit situation, modifying the position request so that it can be followed by the road wheel actuator within power limits, and using the modified position request to generate the motor torque request for the road wheel actuator.

Abstract: A method for power saving in a steering system of a motor vehicle including a road wheel actuator acting on a rack to turn steerable road wheels and a controller configured or programmed to generate an operation signal for the road wheel actuator, wherein the controller includes a position controller to generate a motor torque request based on an actual and/or a measured position of the rack and a requested rack position, includes detecting a passive mode of the steering system by a passive mode detector of the controller if the motor vehicle is stopped and no steering input is provided, and if a passive mode is detected by the passive mode detector, setting the motor torque request to zero in order to save power.

Abstract: The vehicle steering control system includes a control unit configured to control the steering actuator to achieve the steered angle based on at least one of the steering angle and the steering torque. The control unit executes an output restriction control to restrict an output of the steering actuator when a steering torque is equal to or greater than a prescribed threshold value, and cancels the output restriction control when the detection unit has detected a prescribed mode of operation by the operator while the output restriction control is being executed.