Fault Detection of Sun Gear Based on Magnetic Encoder and Narrow Band Demodulation
Instantaneous angular speed(IAS)-based planetary transmission fault detection can effectively over-come the transmission path problem existing in the traditional vibration signal-based analysis method,which has attracted much attention.Conversely,the absolute magnetic encoder has the advantages of low price and conve-nient installation,which is suitable for engineering application,however,its angle signal is significantly affected by measurement error under low speed conditions,so it is necessary to simulate the angle signal so as to elimi-nate the interference caused by measurement error.The traditional segment fitting method tends to result in dis-continuity at the segment point.Such discontinuity leads to false impacts in the IAS signal calculated by it,inter-fering with the fault feature extraction based on the IAS signal.In this paper,a sun gear fault detection method based on IAS estimation and narrowband demodulation of absolute magnetic encoder is proposed.Firstly,in or-der to ensure the continuity and smoothness of IAS signal,a method based on least square fitting and five times Hermite interpolation is proposed to realize the fitting estimation and smoothing of the IAS signal.Secondly,building on this foundation and in conjunction with narrowband demodulation technology,the fault characteris-tics of the sun gear in the planetary gear reducer are effectively extracted.Finally,the effectiveness of the pro-posed method is verified by analyzing and comparing the signals from the absolute magnetic encoder of both nor-mal and faulty sun gears.
magnetic encoderplanetary gearboxinstantaneous angular speed signalnarrow band demodula-tionrotation domain averaging
NETL
NSTL
万方数据
维普
