On modular backstepping design with second order sliding modes

A partially recursive backstepping-like procedure to design estimation-based controllers for uncertain nonlinear systems is presented in this paper. Its motivation relies on the intent of reducing the computational load of the backstepping design by exploiting the simplicity of sliding mode control. The stability features of the system controlled via the proposed approach are semi-global. Its transient behaviour turns out to be comparable with that obtained via the purely backstepping design. The proposed approach exhibits modularity, in the sense that the controller is proved to guarantee input-to-state stability regardless of the choice of the parameter estimation mechanism.