Adaptive Intrusion-Tolerant Control for Constrained MIMO Nonlinear Cyber-Physical Systems Against Hybrid Cyber Attacks

Abstract

In this paper, we are concerned with the tracking control issue for a category of constrained MIMO nonlinear cyber-physical systems (CPSs) with unidentified disturbances, which face the exposure to venomous hybrid cyber attacks. Distinct from most existing related researches which can only address the intrusion-tolerant control issue against single type of cyber attacks, the studied problem in this paper that has not been well resolved is more challenging, where multiple types of network attacks including denial-of-service (DoS) attacks and deception attacks may coexist simultaneously, increasing the design difficulty of intrusion-tolerant controller. Furthermore, by means of designing two error transformation functions (ETFs) and proposing a novel error transformation design technique for resolving the nonlinearity and MIMO coupling problem on the basis of quantifying the destruction mechanism of cyber attacks, a novel adaptive tracking control scheme is ulteriorly developed. As a result, the proposed control architecture owns inherent intrusion-tolerant capability and robustness, which is capable of settling exogenous disturbances and hybrid cyber attacks in unison. In particular, the tracking errors can be forced to convert into the preassigned constrained region at pregiven decay rate in preseted settling time. Finally, the feasibility and superiority of the proposed control framework are illustrated through an emblematic application instance. Note to Practitioners—From the perspective of security defense, great progress has been made in the security research of constrained nonlinear CPSs, such as vulnerability analysis, attack detection and intrusion-tolerant control. However, once the defense mechanism preseted on the cyber layer crashes, the physical side may suffer cross-domain intrusion by malicious adversaries, resulting in the catastrophic non-contact damage. What is worse, the constrained nonlinear CPSs are vulnerable to the simultaneous existing hybrid cyber attacks and unidentified disturbances. Therefore, this paper investigates the tracking control issue for a category of constrained MIMO nonlinear CPSs with unidentified disturbances, which face the exposure to venomous hybrid cyber attacks. By means of designing two error transformation functions (ETFs) and proposing a novel error transformation design technique for resolving the nonlinearity and MIMO coupling problem on the basis of quantifying the destruction mechanism of cyber attacks, a novel adaptive intrusion-tolerant control scheme is ulteriorly developed. As a result, the proposed control architecture owns inherent intrusion-tolerant capability and robustness, which is capable of settling exogenous disturbances and hybrid cyber attacks concurrently. Notably, the tracking errors can be forced to convert into the preassigned constrained region at pregiven decay rate in preseted settling time.