Steering Angle Control of Steer by Wire Systems Considering Nonlinear Characteristic and Uncertainty Parameters

Abstract:

In this paper， a controller is designed for steerbywire systems to achieve the desired steering angle of front wheel. The controller is designed based on the nonlinear characteristic of the selfaligning moment generated by the tyre cornering forces and uncertainty of system parameters. Besides, the constraint of actuators is taken into account. A feedforward and state feedback controller overcoming integral saturation is designed with conditional integrators to achieve the desired steering angle. Based on the nonlinear control theory, a Lyapunov function is built to prove that the steeringbywire control system is asymptotically stable. In the end, the steering angle tracking algorithms proposed are verified by real vehicle tests.

Key words:nonlinear characteristic; steerbywire systems; parameters uncertainty; conditional integrators