Constrained fast finite‐time exact tracking for disturbed nonlinear systems

Abstract

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.