Input-to-State Stabilization of Interval Type-2 Fuzzy Systems Subject to Cyberattacks: An Observer-Based Adaptive Sliding Mode Approach

• Published in: IEEE transactions on fuzzy systems Vol. 28; no. 1; pp. 190 - 203
• Main Authors: Zhang, Zhina, Niu, Yugang, Song, Jun
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.01.2020; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Actuators; Adaptive control; Adaptive systems; Cyberattack; Cyberattacks; Disturbances; Fuzzy systems; input-to-state stability (ISS); interval type-2 (IT2) fuzzy system; Mass-spring-damper systems; Nonlinear systems; Observers; Parameter estimation; Sliding mode control; sliding mode control (SMC); sliding mode observer; State observers; Symmetric matrices; Upper bounds
• ISSN: 1063-6706; 1941-0034
• DOI: 10.1109/TFUZZ.2019.2902105

This paper focuses on the sliding mode control (SMC) problem of interval type-2 (IT2) fuzzy systems subject to the unmeasurable state and cyberattacks. A key issue is how to design a state observer under the constraint that only the bounds of membership functions are known. To this end, this paper introduces two weighting factors to construct a new membership function. Besides, the concept of input-to-state stability (ISS) is utilized to deal with the residual term resulting from the cyberattacks and external disturbances. The sufficient condition is established such that the sliding mode dynamics and the estimated error dynamics are input-to-state stable. Furthermore, by online estimating the unknown parameters in upper bounds of cyberattacks and external disturbances, an adaptive sliding mode controller is synthesized such that the reachability of the prescribed sliding surface can be guaranteed and the effect of cyberattacks on the system performance can be effectively attenuated. Finally, the validity of the proposed method is illustrated by a mass-spring-damper system.