Nonlinear Output Robust Regulation of Ground Vehicles in Presence of Disturbances and Parameter Uncertainties

In this paper a controller based on the so–called robust or structurally stable regulation theory is designed. The ground vehicle motion control is reformulated as a tracking problem of a desired reference, generated by an external system. Moreover, the disturbance acting on the vehicle is supposed to be modeled, i.e. unknown but with a known structure, as happens in many typical situations. The use of immersion techniques eliminates the dependence of the controller on parameters, so obtaining a controller ensuring zero tracking error. Since an immersion for the designed control law can not be easily determined, in this paper we consider the immersion of an approximate expression of the control, so obtaining a bounded tracking error.