Fault detection and isolation in networked control systems with access constraints and packet dropouts

This paper deals with the problem of fault detection and isolation (FDI) of a networked control system (NCS). In this configuration a linear time invariant (LTI) system communicates with controller/FDI over a shared medium. The medium supports a limited number of simultaneous connections between sensors and FDI system. Furthermore, it is assumed that there is the random and unknown packet dropouts in the controller-to-actuator link. Objective is to find a strategy for residual signals generating which network effects are taken into account. In addition, by means of these residuals fault detection and isolation of system is possible. A set of structured residual based on parity relation approach is proposed. It guarantees robustness to system disturbances and packet dropout while each residual is designed to be sensitive to some sensor faults. The efficiency of the proposed approach will be illustrated with a simulation example.