A Novel Distributed Secure State Estimation of Interconnected Cyber‐Physical Systems Under FDI Attacks

ABSTRACT This paper proposes a novel high‐precision distributed secure state estimation strategy for interconnected cyber‐physical systems (CPSs) under false data injection (FDI) attacks. To address the challenge of poor error convergence by existing theoretical suppression of actuator attacks and sensor attacks, intermediate variables and observer matrices are constructed to decouple the impact of actuator attacks, thereby ensuring that the estimation errors of system states and sensor attacks converge asymptotically with an explicitly controlled decay rate. This approach overcomes the precision limitations inherent in conventional methods, significantly improving both estimation accuracy and practical applicability. For the estimation of actuator attacks, distributed intermediate observers are designed based on the method and the observer designed for system state estimation. All observer matrices for actuator and sensor attacks are derived by solving linear matrix inequalities (LMIs). The observer design and stability conditions are based on the original system framework, without employing the popular augmented methods, while reducing communication overhead. Numerical simulations validate the theoretical claims and demonstrate the superior performance of the proposed distributed secure state estimation strategy.