Secure Filter for Discrete-Time Delayed Systems Subject to Cyber Attacks

Cyber Physical Systems (CPSs) are defined as the integrations of computation, control, and communication to obtain a prespecified behaviour of the physical processes. Due to their nature, CPSs could be highly affected by security threats. In this research, a secure filter for discrete-time delayed nonlinear systems affected by the two major kinds of cyber attacks i.e. denial-of-service (DoS) and deception attacks is proposed. The cyber attacks are modelled as Bernoulli distributed white sequences with variable probabilities. First, a predefined level of security is guaranteed by setting a sufficient condition using the techniques of stochastic analysis. Second, we obtain the gains of the proposed filter by solving a linear matrix inequality using YALMIP and MATLAB/Simulink. Finally, a numerical example is solved to show the effectiveness of this method on CPSs.