Secure State Estimation for Systems With Silent Packet Loss and Its Application to Controller Design

This article presents the design of a secure state estimator for systems with silent packet loss (SPL systems) and an unknown packet-loss rate (PLR). Compared with the case of observable packet loss and known PLR, silent packet loss and unknown PLR not only make the implementation of the optimal estimator (OE) infeasible, but also introduce potential security risks. This article aims to address these two issues, and the main contributions are twofold: 1) asymptotically OE: first, parameter estimators are designed to estimate the packet-loss status and the PLR, respectively. Based on this estimator, a state estimator is designed and its performance asymptotically converges to that of the OE and 2) estimator security: stable estimators are not necessarily secure in practical applications. A concept is proposed to characterize the security degree of the estimator. Then, a sufficient condition for secure estimation is established. Based on the estimator, a feedback controller is designed for an SPL system. Some simulations and experiments are presented to verify the results.