Patent ID: 11897551
Assignee: SENTIENT IP AB
Field: Transport (Mechanical engineering)
Classification: CPC B | IPC B

Claim 4:
5. A method for controlling a feedback torque actuator with a motor with an Electric Control Unit (ECU) for giving feedback to a driver, a steering wheel to which the driver applies a driver torque (TD) in a steering system comprising a steering assistance actuator with a torsion bar, wherein the method incorporates the following steps for feedback torque control:
measuring a steering angle using a steering angle sensing means,
measuring a torsion-bar torque with the use of a torsion-bar torque sensor of the assistance actuator,
measuring a current in the motor of said feedback torque actuator,
transforming the current to an estimated feedback torque by the use of a current-to-torque characteristics of the motor,
calculating the driver torque by adding the sensed torsion-bar torque and the estimated feedback torque,
calculating a target feedback torque actuator state from either said calculated driver torque or from said measured steering angle, and
controlling the mentioned feedback torque actuator via a closed loop current control to achieve said target feedback torque actuator state, so that a desired steering feel is achieved.