Instantaneous frequency extraction method based on wavelet in order tracking spectrum analysis

Wavelet was adopted in the extraction of instantaneous frequency of transient vibration signals. With the analysis of characters of instantaneous frequency of transient vibration signals and framework of orthogonal wavelet, a kind of high-pass filter with discrete linear frequency amplitude was derived. It was find out that Haar wavelet was the best orthotropic wavelet used to extract the instantaneous frequency of transient vibration signals. Compared with other wavelets, Haar wavelet has many advantages in application, such as computing quickly and definite physical meanings. And the experiments showed its feasibility and validity in application of real-time processing and analysis of vibration signals.