Experimentations on the adaptive sliding mode control for a trajectory tracking applied on a bi-steerable car

Chattering is known as the most important drawback of sliding mode control (SMC). The latter is robust against external perturbations and model incertitude. The objective of this paper is to provide adaptive SMC laws allowing control of a complex system while avoiding or reducing chatter effects. The controlled system is called Robucar, it is a four wheel mobile robot car in double steering mode also called a bi-steerable car (Bis-Car). It is a non-holonomic, non-linear and under-actuated system. A robust adaptive SMC law is designed to reduce the chatter effect while keeping the robustness properties. The robustness and the applicability of the control laws are shown in simulation tests first, and then in experimental tests where perturbations are considered by introducing errors on the initial position, the traction velocity and the steering angle.