Resilient security control for time-varying delay systems based on switching moving defense method in cyber-physical environment

Nowadays, the increasing cyber threats, and the complexity, diversity, highly integration and openness characteristics of networked systems easily cause critical security problems to the systems’ services and/or components that operating within such environment with dual attributes of physics and information. Security control issue in cyber-physical field, especially for time-delay control systems, requires in-depth research since new problems associated with the emerging integrated techniques arise. This paper study a resilient security control scheme for time-varying delay systems based on switching moving defense method in the cyber-physical environment, to improve its inherent security defense ability. First, the resilient security control model with switching method is formed, time delay and parameter uncertainty factors are both considered, and then the exponential stability conditions for the designed resilient security controller with time delay for time-varying delay system is derived with the Lyapunov stability analysis scheme. Second, three attack detection decision strategies, state-average-energy based detection strategy, abnormal-data-statistics based detection strategy and average-dwell-time-switching based detection strategy, are provided. Third, the moving defense scheme based on switching resilient control and combined attack detection method is proposed. Finally, simulation experiment results are given to show the effectiveness of the proposed approach.