A class of redesigned adaptive robust controllers for nonlinear delayed systems

The problems of robust stabilization and adaptive robust controller design are considered for a class of nonlinear systems with time-varying delays. It is supposed that the nonlinear uncertainties with delayed states can be approximated by neural networks which are not used in the actual control process, and that the time-varying delays are bounded continuous functions. Particularly, the derivatives of the time-varying delays are not required to be less than one. For such uncertain systems, a class of redesigned adaptive robust controllers is synthesized. Furthermore, it is also shown that the proposed control schemes can guarantee the uniform asymptotic stability of such uncertain systems. Finally, a numerical example is given to demonstrate the validity of the results.