Security-Guaranteed Observer-Based PID Control for Nonlinear Networked Systems Under Stochastic Communication Protocol and FDI Attacks

This study focuses on the design of a security-guaranteed observer-based proportional-integral-derivative (PID) controller for discrete-time delayed Takagi-Sugeno (T-S) fuzzy systems subject to stochastic communication protocol (SCP) and false data injection (FDI) attacks. To resolve communication contention, the sensor-to-observer transmission over the constrained channel is coordinated via a SCP, whose switching is described by a Markov chain. Sufficient conditions are derived for constructing mode-dependent observer and controller that guarantee input-to-state stability (ISS) of the augmented dynamics while meeting prescribed security indices. By combining an LMI-based orthogonal decomposition approach with free matrices, the observer and controller gains are systematically computed. Finally, comprehensive simulation studies validate the theoretical advances and confirm the superior robustness and security performance of the proposed scheme under adversarial cyber-physical conditions.