Simultaneous estimation of state and packet-loss occurrences in networked control systems.

The information on data packet loss occurrences in a networked control system (NCS) is useful for improving the control performance and detecting communication failures or cyber-attacks. This study considers the simultaneous estimation of the plant state and packet loss occurrences at each time step. After formulation of the problem, two solutions are proposed. In the first one, an input-output representation of the NCS model is used to design a recursive filter for estimation of the packet loss occurrences. This estimation is then used for state estimation through Kalman filtering. In the second solution, a state-space model of NCS is used to design an estimator for both the plant state and the packet loss occurrences, which employs a Kalman filter. The effectiveness of the proposed solutions is shown during an example, and comparisons are made with another solution based on the interacting multiple model approach to estimation.