Singular perturbation based command filtered back-stepping control for strict-feedback system and application to quadrotor

The command filtered back-stepping technology is investigated for a class of nonlinear strict-feedback form in the paper. A nonlinear anti-tangent filter is adopted to estimate the virtual control, avoiding the analytical deduction inherent in traditional back-stepping method and overcoming the “explosion of complexity” in nonlinear strict-feedback systems. Differing from the existing back-stepping method, the proposed control scheme only requires reference input and their first derivative signals, does not need the prior knowledge of their n
^th
order derivative signals. The stability analysis is completed via the singular perturbation theory, revealing some novel features of the underlying back-stepping method. Finally, a simulation example performed on Quadrotor is provided to illustrate the effectiveness of the control technique.