Non-Fragile Observer-Based Adaptive Integral Sliding Mode Control for a Class of T-S Fuzzy Descriptor Systems With Unmeasurable Premise Variables

Xiaorong Huang; Anca L Ralescu; Yiqiang Peng; Hongli Gao; Shulei Sun

doi:10.3389/fnbot.2022.820389

Non-Fragile Observer-Based Adaptive Integral Sliding Mode Control for a Class of T-S Fuzzy Descriptor Systems With Unmeasurable Premise Variables

Front Neurorobot. 2022 Jul 22:16:820389. doi: 10.3389/fnbot.2022.820389. eCollection 2022.

Authors

Xiaorong Huang¹, Anca L Ralescu², Yiqiang Peng¹, Hongli Gao³, Shulei Sun¹

Affiliations

¹ Vehicle Measurement, Control and Safety Key Laboratory of Sichuan Province, School of Automobile and Transportation, Xihua University, Chengdu, China.
² Department of Electrical Engineering and Computer Science, University of Cincinnati, Cincinnati, OH, United States.
³ School of Mechanical Engineering, Southwest Jiaotong University, Chengdu, China.

Abstract

The issue of non-fragile observer-based adaptive integral sliding mode control for a class of Takagi-Sugeno (T-S) fuzzy descriptor systems with uncertainties and unmeasurable premise variables is investigated. General nonlinear systems are represented by nonlinear T-S fuzzy descriptor models, because premise variables depend on unmeasurable system states and fuzzy models have different derivative matrices. By introducing the system state derivative as an auxiliary state vector, original fuzzy descriptor systems are transformed into augmented systems for which system properties remain the same. First, a novel integral sliding surface, which includes estimated states of the sliding mode observer and controller gain matrices, is designed to obtain estimation error dynamics and sliding mode dynamics. Then, some sufficient linear matrix inequality (LMI) conditions for designing the observer and the controller gains are derived using the appropriate fuzzy Lyapunov functions and Lyapunov theory. This approach yields asymptotically stable sliding mode dynamics. Corresponding auxiliary variables are introduced, and the Finsler's lemma is employed to eliminate coupling of controller gain matrices, observer gain matrices, Lyapunov function matrices, and/or observer gain perturbations. An observer-based integral sliding mode control strategy is obtained to assure that reachability conditions are satisfied. Moreover, a non-fragile observer and a non-fragile adaptive controller are developed to compensate for system uncertainties and perturbations in both the observer and the controller. Finally, example results are presented to illustrate the effectiveness and merits of the proposed method.

Keywords: T-S fuzzy descriptor systems; integral sliding mode control; non-fragile control; nonparallel distributed compensation control; observer design; unmeasurable premise variables.