An Adaptive Secure Control Scheme for T–S Fuzzy Systems Against Simultaneous Stealthy Sensor and Actuator Attacks

Abstract

This article studies secure control problems for T-S fuzzy systems equipped with a Luenberger-observer-based anomaly detector, when simultaneously subjected to stealthy sensor and actuator attacks. A key issue is that stealthy attacks can maliciously compromise control inputs, sensor outputs, and fuzzy controller's premise variables which depend on measurable states, while bypassing detection from an anomaly detector, so that they may leave the conventional control schemes invalid. To solve it, 1) by considering the impact of sensor attacks on premise variables of fuzzy controller, a new fuzzy controller with reliable premise variables constructed by the trusted sensor's and introduced filter's outputs is proposed and also a design condition for the controller with the guaranteed desired <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> performance is given via the property of fuzzy product inference engines. 2) With the aid of the detection mechanism and attack's structural information, an upper bound for stealthy attacks is given, which from the defender's viewpoint quantifies a class of stealthy attacks. Based on the bound, a novel adaptive attack compensator is presented such that the developed fuzzy controller with the compensator guarantees the stability of the attacked systems with a desired control performance. Three illustrative examples validate the proposed method.