Fault diagnosis based on the multiple preset GFRF models

The fault diagnosis based on the nonlinear spectral analysis is a new method with wide application foreground. The online computation of the generalized frequency response functions (GFRF) is needed in the standard fault diagnosis method based on nonlinear spectral analysis. Because the realization of GFRF identification in frequency domain is difficult, the application of this method in engineering field is limited. For avoiding to estimate the current GFRF´s of the analyzed system in the fault diagnosis based on nonlinear spectral analysis, a new diagnosis method, which is based on the multiple preset GFRF model and the simplified GFRF identification algorithm, is presented in this paper. And this method has been used to diagnose the fault of the actual vehicle damping spring, the test results indicate that the presented method is efficient. This method can not only exploit the advantages of the GFRF model and the simplified identification algorithm, but also avoid estimating the GFRF online. Furthermore, its computation requirement is small, and its realization by using microprocessors is convenient.