Fault Detection for Dynamic Systems based on Multirate Sampling

In many complex systems such as distributed multi-sensor systems, different sensors may work with multiple sampling periods. In this paper, the problem of fault detection for this kind of systems is considered. Firstly, by mapping the multirate measurements onto fast time instants, a new measurement equation with variable dimensions is obtained. Based on this, a multirate Kalman filter based residual generator is designed to deliver residual signal at a fast rate, which is further evaluated in a dynamic window. The proposed scheme has no need to process some troublesome issues such as noise correlation and causality constrains caused by traditional lifting technique. A numerical simulation is presented to illustrate our approach.