The virtual force feedback for torque estimation and control in a vechicle Steer by Wire (SBW) system

Abstract

This study presents the method to generates and control a force feedback with torque control for a driver steering feel in a vehicle steer by wire (SBW) system. The control algorithm of force feedback was developed by simulation and validated through experimental to investigated the steering and control performance. This is done by constructed a steering wheel rig hardware in the loop (HIL) and interfaced to Matlab XPC target software. Two method are proposed to generate and control a force feedback whereby the current measurement is a main element used to estimates the steering torque . For the first control algorithm, the torque at the front axle system and self aligning are used to generate a force feedback and the PID controller with fuzzy system (PID+Fuzzy) are used to control a feedback torque. Meanwhile, the reference model was used to improves the centering steering wheel position. For a second control algorithm, the torque map and torque of steering wheel and front axle system are used to generate the force feedback. Meanwhile, the LQR control with gain scheduling (LQR+GS) are used to control the torque. Furthermore, the compensation torque is used to improves the steering feel and to stabilize the system by varying a compensation gains. The results demonstrate shown, that the torque control using a LQR+GS method is improves against a torque map and 90% similar to Electric Power Steering (EPS) system. This is because there are multiple gains varying that able to improve a steering control performance. On the others hand, the hyperbolic tangent and linear equation proposed improves a vehicle maneuverability at low and high speed.