Wear status recognition of piston pump based on side frequency relative energy summation

Wear is a kind of progressive failure in piston pumps on aircrafts. As amount of wear is difficult to directly measure, vibration signal is often used to reflect it. However, characteristics of the vibration signal caused by wear are usually weak, and it is difficult to make an accurate recognition of the wear status. Considering these problems, a recognition method of wear status based on relative energy summation of side frequency was proposed, vibration signal of piston pump was addressed with Hilbert envelope demodulation to eliminate high frequency cycling interference, and clear harmonic components were acquired, the summation of the maximum energy to average energy ratio in the side band of each harmonic frequency was used as the indicator to reflect the wear status of piston pumps, the grid search method was used to optimize the range of the side frequency. Experimental results show that side frequency relative energy summation has higher distinction and is suitable for wear status recognition compared with the traditional frequency energy.