Hydraulic Impactor Performance Testing Based On Wavelet Analysis

The exact test of hydraulic impactor machine is one of the most important methods to develope hydraulic impact technique and seek amelioration of product's capability. The thesis synthetically analysis the advantage and disadvantage of testing methods at home and aboard, put forward a new method-displacement sense way. And combine air pressure way to build the testing system and test impacting capability of the hydraulic impactor machine.The displacement sense way is an improvement of touch way, and has high precision. Air pressure is the sole detecting value of air pressure way. Because of the particularity of impactor machines, the signal gathered contain much noise,the effect of signal processing is in relation to the accuracy of hydraulic impact machines'capability parameter. After comparing some denoising methods,we choose wavelet transform to denoise the nitrogen pressure.The author has worked out and confirm the optimum wavelet base which is much more suitable for the pressure signal of impact signal. On considering the mathematical characteristics of wavelet base such as tight support, vanishing square, symmetry and so on, the ability for wavelet base to reconstruct signal and the accuracy for wavelet base to extract the characteristics of the signal, The author build the de-noising arithmetic with modulus maxima and wavelet threshold to apply to the pressure signal de-noising.Finally, the experiment table is established ,and the experiment result validate of the testing method and data processing method.The above conclusions have definite guidance meaning for application and tructure amelioration of the hydraulic impact mechanism.