Constrained fast finite-time exact tracking for disturbed nonlinear systems

Abstract

This article investigates the fast finite-time exact tracking problem for nonlinear systems with time-varying disturbances. A new composite controller with a finite-time disturbance observer is proposed to achieve fast finite-time exact tracking. Furthermore, a new time-varying barrier power integrator technique is developed to design the controller. This can ensure not only asymmetric/symmetric time-varying full-state constraints but also singular-free continuous control effort. To reduce the complexity of computation, fuzzy logic systems are adopted to approximate complex nonlinearities. Finally, an example of single-link robot systems subject to time-varying disturbances is presented to show the validity of the proposed method.