Adaptive tracking control for a class of unknown nonlinear time-delay systems using nonlinearly parameterized fuzzy approximators

A class of strict-feedback nonlinear systems with unknown system functions and time delays are considered in this paper. Nonlinearly parameterized fuzzy systems with adaptive mechanism are employed to approximate the unknown functions in a backstepping procedure. By using Taylor series expansion, the parameters are separated successfully, then adaptive laws can be designed to update them on-line. The advantage of such a design is that the basis functions of the fuzzy approximators are not require known before design. The proposed controller can guarantee the closed-loop stability and good tracking performance.