An ADAS-Oriented Virtual EPS Platform Based on the Force Feedback Actuator of the Steer-by-Wire System

Electric Power Steering (EPS) is the actuator of several lateral-dynamic-related Advanced Driver Assistance Systems (ADAS). A driving simulator with EPS will be much helpful for the ADAS development. However, if a real EPS is used in the driving simulator, it is quite difficult to realize the road reaction force accurately and responsively. To overcome this weakness, a virtual EPS platform is established. The virtual EPS platform contains two parts: one is the vehicle and EPS model, the other is the force feedback actuator (FFA) of the Steer-by-Wire (SBW) system. The FFA is an interface between the driver and the EPS/vehicle model. The reactive torque of the FFA is obtained based on the models. Meanwhile, the input of the EPS model is the steering angle of the FFA. Comparing to a real EPS, the virtual EPS platform has a problem of instability because of the actuator lag of the FFA. Therefore, a damping control method is applied to make the system stable. In addition, to make the steering characteristic of the FFA the same to that of the EPS model, the disturbance observer is introduced. The controller design based on the damping control and the disturbance observer is first conducted in the offline simulation and then modified on the test bench. At last, bench experiments are conducted to validate the virtual EPS platform. The results show that the steering characteristic of the EPS is well accomplished by the platform, and the steering feel is acceptable.