Hierarchical control of overactuated vehicles via sliding mode techniques

Overactuated vehicle platforms with in-wheel motors make it possible to realize vehicle control systems that can yield the desired dynamic response while simultaneously optimizing various performance criteria. In this context, this paper analyzes how sliding mode techniques can be profitably applied to the yaw-rate tracking problem that governs the high-level vehicle control layer. Specifically, three different algorithms are compared: the standard, the switched and the adaptive formulations of the second-order sliding mode controller. Extensive simulation and hardware-in-the-loop (HIL) testing show that adaptation features allow more flexibility and a better closed-loop behaviour in the face of the uncertainties affecting the overall system.