Robust fault diagnosis of networked control systems via Kalman filtering

The fault detection problem of a class of linear networked control systems (NCS) with communication delays will be studied in this paper. The aim of the study is to generate residual signals which, in the fault free case, are supposed to be identically zero. In practice, this condition is not satisfactory due to various factors such as measurements noise, model uncertainties, and more specifically the NCS communication induced delays. The effect of unknown networked induced delays on conventional observed residue generator is also studied in this paper. It is shown that the detection performances may be deteriorated because of the sensitivity of the residuals to the delays. The proposed approach is based on robust residual generation based on Kalman filtering.