Abstract: Methods of controlling a feedback torque actuator in a steering system that includes the feedback torque actuator and an assistance actuator incorporate, for feedback torque control, generating at least one input signal with a sensor, determining a steering angle from the input signal, transforming the steering angle to a target steering-wheel torque, and controlling the feedback torque actuator via a closed loop current control to achieve the target steering-wheel torque. The assistance actuator has a high gain, thereby resulting in a low torque in the axle above the assistance actuator such that the steering-wheel torque is close to the target steering-wheel torque, whereby acceptable steering feel is achieved.

Abstract: Methods for controlling a feedback torque actuator and at least one yaw and/or lateral vehicle state actuator in a steer-by-wire steering system include measuring an input signal with a sensor, determining from the input signal a measure of a torque applied by the driver via a steering wheel, transforming the measure to a desired yaw and/or lateral vehicle state, controlling the yaw and/or lateral vehicle state actuator for vehicle state control, and defining a steering-wheel torque to steering-wheel angle relation describing steering feel. If the vehicle position control results in a yaw and/or lateral vehicle state error, this error is transformed to a change in the steering-wheel torque to steering-wheel angle relation describing steering feel. This new steering feel relation is used as an input signal for controlling the feedback torque actuator in order for the driver to get feedback of the yaw and/or lateral vehicle state error.

Abstract: A method in controlling a steering assistance actuator in a steering system (100) of a vehicle and one or more controllable vehicle state actuators so that the steering-wheel torque applied by the driver is an indicative for the driver intention and transformed to a target yaw and/or lateral vehicle state to be controlled by one or more vehicle state controllers and actuated by the vehicle state actuators along with the fact that the level of understeer is used to achieve an additional steering-wheel torque in the form of a ramp in the steering-wheel torque as a function of the level of understeer.