Observer-Based Active Control Strategy for Networked Switched Systems against Two-Channel Asynchronous DoS Attacks

This paper addresses the security issue of networked switched systems under two-channel asynchronous denial-of-service (DoS) attacks, where the measurement channel and the control channel are subject to DoS attacks independently. For the case of partial-state measurements, an observer-based active control strategy is proposed to mitigate the negative impact on the control performance and stability of the system caused by the attacks. In this strategy, a novel mode-dependent finite-time observer is designed to estimate the system state rapidly and accurately, the predictor and the buffer are designed to ensure that the control signals transmitted to the actuator can be updated even when the control channel is blocked. Compared to the earlier results on the active control strategy that only consider the case of full-state measurements and assume that the DoS signals followed specific patterns, our work only limits the frequency and duration of the DoS signals, which is more general and challenging. Furthermore, the switching signal is designed to ensure the input-to-state stability (ISS) of the networked switched system with the active control strategy under two-channel asynchronous DoS attacks and asynchronous switching behaviors. Finally, the effectiveness and the merits of our work are validated through an example and a comparative experiment.