Admittance based position tracking using sliding mode controller for an electric power steering system

This paper presents position control by a sliding mode controller for electric power steering system for ground vehicles based on admittance control. The desired admittance of the system is defined by an impedance filter. The apparent admittance is enforced by a position tracking control loop. In the proposed control framework, the base admittance of the system under T bar is considered, which determines the steering feel. The separation of position control loop and steering feel configuration reduces the calibration and system tuning time. The motor loop of the electric power steering (EPS) is controlled by a PI controller in order to provide sufficient torque assistance. The simulation results show position tracking is effective at all road reaction frequencies and base steering matches the designed steering feel.