Abstract: The present invention relates to a system and a method for controlling a feedback torque actuator in a steering system. The steering system comprises a steering assistance actuator (140) with a torsion bar (128) and a feedback torque actuator (130) with an Electric Control Unit, ECU, for giving feedback to a driver, a steering wheel (120) to which the driver applies a driver torque, TD. Only the torsion bar of the steering assistance actuator (140) comprises a torsion-bar torque sensor, and a target torque for the feedback torque actuator (130) is a target steering feel torque compensated for torque sensed in the torsion bar (128).

Abstract: A method and a system for vehicle steering control by controlling a feedback torque actuator (130) in series with an angle overlay actuator (140) in a vehicle steering system (100) to provide a target feedback torque and a target overlay angle. The feedback torque actuator (130) is arranged above the angle overlay actuator (140). The angle overlay actuator (140) is controlled so that a variable steering ratio and an additional overlay angle are provided, and the feedback torque actuator (130) is controlled using a reference generator so that the torque is controlled to provide a target steering feel, resulting in the angle overlay being controlled at the same time as the steering-wheel torque being controlled whereby a target overlay angle and a good steering feel are achieved.

Abstract: The present invention relates to a method for controlling vehicle lane holding for a vehicle with an electric power assisted steering by means of a steering system (100) with a steering assistance actuator and one or more controllable vehicle state actuators comprising measurement of at least one vehicle position input signal with using an on-board vision system for determination of a relative vehicle lane position in the form of a lateral lane position, a heading angle and a lane curvature, transformation of the relative vehicle lane position to a target yaw and/or lateral vehicle state, measuring at least one steering input signal, determination from said one or more measured steering input signals a torque value applied by the driver via a steering wheel (120), transformation of said torque value to a relative to the afore-mentioned target yaw and/or lateral vehicle state a driver target relative yaw and/or lateral vehicle state, adding said target yaw and/or lateral vehicle state and said driver target re

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.