A nonlinear tracking controller for a haptic interface steer-by-wire systems

A nonlinear tracking controller is presented in the paper for the haptic interface in steer-by-wire automotive systems. Specifically, the controller is designed to ensure that the steering mechanism (i.e., directional control assembly) follows the operator commanded maneuvers at the driver interface. Further, the controller provides the driver with tunable force feedback, proportional to the reaction forces at the tire-road interface, and hence enhances the driver´s performance. The controller ensures that the corresponding tracking errors are asymptotically forced to zero in the presence of parametric uncertainty; however, torque measurements are required. An extension is also presented that eliminates torque measurements.