The Feature Extraction Method of Gear Magnetic Memory Signal

Abstract

Magnetic memory test technology is a new nondestructive testing technique, which is able to detect of the stress concentration area and potential fault of low speed and heavy load gear. Because the magnetic memory signals are easy to be disturbed by various sources of noises, a new method based on the intrinsic time-scale decomposition (ITD) is proposed to achieve the extraction of magnetic memory signal. Firstly, the magnetic memory signals are decomposed into several proper rotation components (PRC) and a trend component by ITD. Then reconstruct the first four order PRCs to eliminate the low frequency cyclic composition of magnetic memory signal and magnetic noise. Finally, the magnetic signal strengths of each gear tooth root are extracted using cycle average and local statistic method. The results of Experiments show that the method is suitable to pick up effective ingredients of signal to extract signal feature and has important application value in potential fault diagnosis of low speed and heavy load gearbox.