FEATURE EXTRACTION BASED ON MODIFIED

 MATCHING PURSUIT AND ITS APPLICATION

FAN Hong^{1, 2}  MENG Qingfeng¹  ZHANG Youyun¹  FENG Wuwei¹  GAO Qiang³

(1. School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049;
2. School of Computer Science, Shaanxi Normal University, Xi’an 710062;
3. School of Automobile, Chang’an University, Xi’an 710064)

Abstract: Feature extraction of vibration signal as a part of condition monitoring and fault diagnosis of mechanical equipment is a fundamental and key issue and has been proven to be highly effective. Focusing on the defects of different signal representation, an adaptive signal decomposition technique is presented to extract fault feature waveform from vibration signals. This method is a modified algorithm of matching pursuit (MP) which decomposes the observed signal into series of expansion of waveforms, these waveforms are calculated by the nonparametric waveform estimation (NWE) and used to best match the signal local structures. So, the construction of general basis function described by some parameters is unnecessary. A prior information about the observed signal is no more required for the template signal in the NWE owing to applying the adaptive template signal, which felicitates the method for a wide variety of applications. Both computer simulation and experimental results verify this approach is practicable and effective, even if the noise frequency band coinsides with that of the feature waveform of the signal.

Key words: Feature extraction Matching pursuit Nonparametric waveform estimation

CLC No: TN911.6

国家自然科学基金(50475087)和陕西师范大学重点基金资助项目. Received 20061024, received in revised form 20070305