Wavelet transform based de-noising method on pipe vibration signals of aircraft

Testing signals of aircraft pipe vibration test in experimental flight is usually accompanied with the noise of high amplitude and wide frequency band. The frequency band of the noise signals covers the whole frequency band of sampling. It causes that testing signals acquired in flight cannot be processed to obtain the characteristic parameters of pipe vibration, such as acceleration and displacement, so as to reduce test accuracy and efficiency. A continuous complex wavelet transform based de-noising method is studied. The continuous complex wavelet transform is used to extract the signal components of testing signals in the frequency range of resonance frequency so as to reduce harmonic wave noise and Gaussian white noise mixed in the testing signals and to acquire the condition of pipe vibration in flight process more efficiently. This method is validated by de-noising a simulated signal and a testing signal of an aircraft pipe vibration in experimental flight.