Noise Analysis of Air Disc Brake Systems Using Wavelet Synchrosqueezed Transform

Abstract

Recently, signal processing methods are shown to be successful while diagnosing faults in mechanicalsystems, using noise or vibration data. In this study, two different faulty air disc brakes; noisy and lessnoisy ones are investigated using Wavelet Synchrosqueezed Transform on audio recordings. Thedifference between two types are shown in scalogram and also verified by a quantitative measure ofentropy. The audio recording has been carried out by using two identical microphones sited on the brakesvia data acquisition unit at a sampling rate of 20 kHz, 16-bit resolution and these data are analyzed inMATLAB software. The average of the entropy values of faulty and non-faulty brakes were found to be0.98 and 0.65, respectively. Therefore, it has been concluded that, the entropy could be used as adistinguishing tool to discriminate the faults.