Detector-based Non-Fragile Control for Interconnected Servo Systems under Hybrid Attacks

This paper investigates a non-fragile security control strategy for interconnected servo systems based on the proposed credibility factor observer. The strategy mainly defends against covert false data injection (FDI) attacks and denial-of-service (DoS) attacks in the network environment, and solves the controller jitter problem. First, a mathematical model of the networked servo system is developed and the existence of covert FDI attack and DoS attack is considered. Then, a dynamic adaptive threshold cryptographic detection algorithm is proposed to detect network attacks. Furthermore, based on this detection algorithm, a credibility factor-based observer is designed for obtaining the accurate system state. In addition, for the command signal jitter problem of interconnected system, a non-fragile robust control strategy is proposed to effectively suppress the impact of noise and jitter on the system performance. Finally, the effectiveness of the proposed strategy is verified by simulations and experiments.