A Wavelet-based Parity Space Approach to Fault Detection of Linear Discrete Time-varying Systems

This paper deals with the problem of parity space-based fault detection (FD) for linear discrete time-varying systems. In order to simultaneously ensure the performance of FD and avoid the heavy computational burden of high dimensional parity space, the techniques of stationary wavelet transform (SWT) on residual signals are applied in the paper. Based on this, the design of residual generators can be formulated as generalized optimization problems and a recursive algorithm is developed to a feasible solution of parity vectors. Furthermore, a bank of residual signals are generated at multiscales. The significant advantage of the SWT based parity space approach is the improvement of FD performance with low parity space order and an easy online realization. Finally, a numerical example is given to demonstrate the effectiveness of the proposed approach.