Abstract: The principle and algorithm of accurate extracting the characteristic information of transient signal with wavelet transforms are described, and the phase characteristics of transient signal with wavelet transforms are analyzed. Using the analytical method of the wavelet ridge of transient signal, the correspondence between wavelet ridge of transient signal and characteristic information of transient signal is described in detail. The distinguishing model and accurate extraction for the characteristic information of transient signal are established. Examples of application demonstrate that this method presented is easy to realize the accurate extracting of the characteristic information of transient signal with serious noise. Results show that the positioning error is less than one sample interval; In addition, this method is also featured by high analysis precision with no accumulative error and real time performing in application as well.

Key words: Characteristic information, Distinguishing model, Instantaneous frequency, Transient signal, Injection molding, Microscopic structure, Numerical simulation, Metal-polymer composite