  Estimating the occurrence of packet losses in a networked control systems
(NCS) can be used to improve the control performance and to detect failures or
cyber-attacks. This study considers simultaneous estimation of the plant state
and the 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 solutions is shown during an example and comparisons are made between the
proposed solutions and another solution based on the interacting multiple model
estimation method.
