Compliant control of steer-by-wire systems

Vehicle directional control and driver interaction assemblies have been built to study and implement impedance control strategies on a steer-by-wire system. Adaptive online estimation is used to identify the dynamic parameters of vehicle directional control and driver interaction assemblies. A nonlinear 4 DOF vehicle model, including longitudinal, lateral, yaw and quasi-static roll motions is derived using Newtonian mechanics to simulate and test the impedance control strategies developed. Impedance control strategy is used to control the dynamic characteristics of the steering system for improving the steering-feel and vehicle stability.