Robust sliding mode control for a class of nonlinear systems through dual-layer sliding mode scheme

This article investigates the topic of robust sliding mode control for a class of nonlinear systems in the presence of actuator faults and disturbances. By virtue of a novel integral sliding function combined with an auxiliary controller ' & nu;(t) ', a dual-layer sliding mode control framework is established. For system responses, the first layer is an integral sliding mode generated by the actuator output, the second layer is a nonlinear sliding mode generated by ' & nu;(t) '. Under the proposal, the nonlinear sliding mode is nested in the integral sliding mode. Compared with the state-of-the-art integral sliding mode control (ISMC) results, not only the inherent robustness is retained, but also the time derivative of integral sliding function can be resisted by ' & nu;(t) '. Accordingly, the designed integral sliding mode controller provides more enhancive robustness. With the nested nonlinear sliding mode generated, the matched time derivative of integral sliding function in integral sliding motion dynamics is decoupled from the mismatched disturbances. This decoupling contributes to design a sliding mode controller for ensuring that the system states are uniformly bounded with time-varying performance boundaries. Further, by employing a class of vector-value functions, a novel continuous sliding mode controller is presented such that the sliding modes of the considered systems cannot be lost regardless of actuator faults and disturbances. At last, an illustrative example verifies the effectiveness of the theoretical findings. & COPY; 2023 The Franklin Institute. Published by Elsevier Inc. All rights reserved.