Application Of Grey Target Theory In Failure Pattern Recognition Of Hydraulic Pupmp

Hydraulic system has been extensively used by its excellence such as high power and quick response in engineering area and it plays an essential role in control and transmission of many equipments. The pump is the"heart"of the hydraulic system, so the condition monitoring and fault diagnosis of the pump is crucial for the hydraulic system.In reality often access to incomplete information due to the imperfection detection means,signal acquisition device instability, or lack of effective observational tools。This paper introduction grey target theory and grey relational analysis method used in hydraulic system failure diagnosis. Use the existing information to extrapolate the unknown information with the characteristics, status and trends, and predict the future development of the hydraulic system.LabVIEW is used to design the data acquisition software of hydraulic pump. With the soft the NI DAQ card is driven and the signal of hydraulic pump is measured.Using MATLAB software effectively remove high frequency noise signals of vibration signal by wavelet packet decomposition and reconstruction.This paper studies the Grey Correlation Analysis of the Grey theory, and discuss the extract method based on wavelet packet decomposition band energy, using MATLAB software, recognition four fault types of the hydraulic pump.Study principal component analysis, make hydraulic pump composite fault independent after a series of transformation. To further determine fault type laid a foundation.Contrast maximum entropy spectral estimation and classical power spectrum estimation, use maximum entropy spectral estimation for hydraulic pump complex vibration signal analysis. In the course of analysis without fixed window function, so can avoid energy leakage problem. Using MATLAB software extract loose boots fault signal characteristics. Obtain breakdown characteristic frequency.By studying the target theory analysis of the grey theory, analysis of the severity of different fault sliding wear boots, calculate approaching degree to determine the fault level.