Sliding mode control with self-turning law for uncertain nonlinear systems with time-delay and external disturbances

This study proposes a novel sliding mode control with self-turning law for nonlinear systems with time-delay and external disturbances possessing uncertain parameters. The adjustable control gain and a bipolar sigmoid function are online tuned to force the tracking error to approach zero. The proposed control scheme provides good transient and steady-state performance. Moreover as the proposed controller, the chatting phenomenon can be avoided and the problem of time-delay and external disturbances are solved for a class of nonlinear systems. The closed-loop control system stability is proved to use the Lyapunov method. Steady-state system performance and chattering are considerably improved. Numerical simulation results are given to illustrate the effectiveness of the proposed procedure. © Springer-Verlag Berlin Heidelberg 2014