Optimal linear filter design for process state and packet loss estimation in networked control systems

ISA Trans. 2024 Apr:147:79-89. doi: 10.1016/j.isatra.2024.01.030. Epub 2024 Jan 27.


Considering the effect of packet losses on the behavior of networked systems, this work is concerned with estimation of the packet loss occurrences in the input channels possibly together with the system state. For this purpose, the commonly used Markov chain model of the successive packet loss occurrences is transformed to a linear recursive model in which the packet loss occurrence variables appear as new state variables. Two methods are proposed for combining the recursive packet loss model with the plant model to obtain an overall model for the whole networked control system (NCS). In the first method, a state space model of the plant is used which allows for simultaneous estimation of the packet loss occurrences and the plant state. In the second method, an input-output model of the plant is employed which allows for estimating only the packet loss occurrences. Both the zero and the hold packet loss handling strategies are considered and stability of the filters is analyzed. The proposed methods are compared with some existing results during an example to show their advantages.

Keywords: Networked control systems; Observability; Optimal estimation; Packet dropout; Packet loss estimation; State estimation.