An H∞H∞ approach to fast rate fault detection for multirate sampled-data systems

In this paper the problem of fault detection in multirate sampled-data systems is studied. The lifting technique and direct design approach are used to convert the time-varying multirate design problem into an equivalent time-invariant single-rate discrete-time problem. A performance index is optimized to obtain a set of H∞H∞ optimal and causal residual generators. The key new feature of such a residual generator is that it operates at a fast rate for prompt fault detection.