Adaptive sliding mode control for a class of uncertain nonlinear systems

Adaptive sliding mode control strategy for a class of uncertain nonlinear systems using Lyapunov´s stability theory is proposed. The mechanism is as follows: the system is divided into nominal model and lumped disturbance term, an adaptive control is adopted to reduce the lumped disturbance to an acceptant bound within finite time, and a sliding mode control is adopted to enable the tracking errors of the uncertain nonlinear system to approximate to zero ultimately. The scheme not only has a good robustness for the uncertainties but also overcomes the chattering in the control input of conventional sliding mode control. It is applied to a class of high-order single-input-single-output and multi-input-multi-output uncertain nonlinear system, and the stability is proved. The result is supported by simulation of the attitude control of flapping wing micro air vehicle, and the validity of the proposed method is verified.