Quasi-sliding mode control for lane keeping with bounded and varying parameters

In the presence of parametric uncertainty, such as the mass of vehicle, inertia of vehicle about vertical axis, and tire cornering stiffness of vehicle, the lane keeping control for automated highway systems was studied. Two cases were investigated: the bounded time-varying parameters and unknown slowly varying parameters. Applying the look-ahead scheme and vehicle lateral dynamic mode, the dynamical equations of lateral displacement error and yaw angle error at the look-ahead distance were established. By using the method of quasi-sliding mode, the variable structure control law for lane keeping was designed. The stability of control system was analyzed using Lyapunov theory. Simulation results show that the control scheme proposed here not only has a strong robustness to parametric uncertainties, but also has a good tracking performance without the disadvantage of control chattering.