Sliding mode control for IT2 fuzzy semi-Markov systems with faults and disturbances

The composite fault-tolerant control problem for semi-Markov jumping nonlinear systems with time delays, uncertainties faults and multiple disturbances is addressed in this paper. The main intention of this work is to design a sliding mode control (SMC) law via an interval type-2 (IT2) fuzzy approach in such a way that it attenuates and rejects the impacts of uncertainty, nonlinearity, faults and external disturbances. Notably, first, an IT2 fuzzy disturbance observer is formulated to estimate the external disturbances and then an IT2 fuzzy fault diagnosis observer is designed to estimate the faults effectively. Next, a SMC-based fault-tolerant strategy is developed to compensate the diagnosed faults and disturbances satisfactorily. By using the linear matrix inequality and Lyapunov technique, the required stability constraints are developed with prescribed H-infinity performance index. The importance and effectiveness of the developed composite fault-tolerant control scheme are finally validated through two numerical examples. (c) 2022 Elsevier Inc. All rights reserved.