Quasi-output feedback global sliding mode tracker for uncertain systems with input nonlinearity

Abstract

This paper presents a novel concept of quasi-output feedback global sliding mode tracker to achieve robust tracking and model following for uncertain systems subject to input nonlinearity, time-delays, time-varying parameter uncertainties and external disturbances. In contrast to the traditional sliding mode control, the reaching phase and the chattering phenomenon are eliminated, and the knowledge of the upper bound of uncertainties is not needed beforehand. Moreover, the proposed robust tracker guarantees that the tracking errors decrease to a predictable neighborhood of zero when input nonlinearity, time-delays, time-varying parameter uncertainties and external disturbances are presented. Finally, numerical simulations are provided to demonstrate the effectiveness of the proposed control method.