APPLICATION OF ORTHOGONAL WAVELETS TO EARLY GEAR DAMAGE DETECTION

Use of the orthogonal wavelet transform to detect abnormal transients generated by early gear damage from the gearbox casing vibration signa l is discussed. Orthogonal wavelets, such as Daubechies 4 and harmonic wavelets, are used to transform the time domain synchronous vibration signal into the time-scale domain. The orthogonal wavelet transform u ses fast algorithms and decomposes the signal onto the minimum number of wavelet series. However comparison with the non-orthogonal wavelet transform for the same length of discrete data shows that the descript ion of the signal in the 3-dimensional map of the wavelet transform is not sufficiently comprehensive due to limited scales. (C) 1995 Academ ic Press Limited