Adaptive Secure Control of Uncertain Second-order Nonlinear Cyber-physical System against Intermittent DoS Attacks

Cyber-physical systems (CPSs) are often complexly nonlinear and uncertain. This paper investigates the adaptive output-feedback control problem for CPSs subject to intermittent denial-of-service (DoS) attacks. The considered CPSs are modeled as a class of uncertain second-order strict-feedback nonlinear systems. When a DoS attack is active, the output signal becomes unavailable. To overcome this diffculty, an adaptive observer is constructed. Based on an average-dwell-time (ADT) method incorporated by frequency and duration properties of DoS attacks, convex design conditions of controller parameters are derived by solving a set of linear matrix inequalities (LMI). The proposed controller guarantees that all closed-loop signals remain globally bounded. An illustrative example is included to validate the theoretical results.