Multi-Input Sliding Mode Control for Path Following in Four Wheel Steering Autonomous Vehicles

Many studies have been focused on the automatic control of autonomous vehicles, using different control methods. In this paper, a multi-input sliding mode controller (SMC) is proposed which enables the autonomous vehicle to track a double lane change path with a constant longitudinal velocity, leveraging the capability of four-wheel steering (۴WS). The lateral errors’ dynamics are formulated in such a way that two independent SMC are designed for lateral preview offset and heading error. The proof of stability for multi-input SMC is provided, also the switching control laws are smoothly interpolated in boundary layers to deal with the chattering issues. Simulation results confirm that the proposed controller is able to make the lateral preview offset and heading error converge toward zero, despite the un-modeled dynamics and parametric uncertainties.