Robust adaptive control of time-varying systems with unknown backlash nonlinearity

This paper presents a robust adaptive controller for time-varying systems with an unknown backlash nonlinearity at the plant input. The controller is designed based on the pole assignment strategy, and it is applicable even to systems in the presence of unmodeled dynamics, bounded external disturbances, and time-varying parameters. No minimum phase assumption and no persistence of excitation requirement are needed. The global stability is ensured by the proposed controller.