Design of control logic and compensation strategy for electric power steering systems

The purpose of this research is to develop an electric power steering (EPS) control logic which integrates base-assist, damping, return, and inertia control logic. This research also introduces a special method which employs the steering angle signal and the vehicle speed signal into the control logic to tune the compensation gain immediately. It can optimize the steering response and improve the steering feel. In addition, a new control logic, impact compensation, has been proposed. It reduces the oscillatory effect of the steering system when the vehicle passes through an uneven road. For verifying the ideas mentioned above, this research integrates Matlab/Simulink with CarSim. Co-simulation technique is used to validate the proposed ideas for the high accurate description of vehicle dynamics and model of the steering behavior. The results show that the designed control logic and compensation strategy can satisfy various driving conditions. The impact control logic can alleviate the unwanted vibration of the steering wheel effectively.