Valve clearance fault detection based on wavelet packet analysis
Si Jing-ping1; Ren Qing-shuang1; Liang Hong-bo2; Zhang Bao-wei1
1. School of Energy and Power Engineering, Inner Mongolia University of Technology, Hohhot, 010051, China;2. Engine Research Institute of North China, Datong, Shanxi, 037004, China
Abstract：Taking the DA462 engine as the object, this research adjusted the valve clearance artificially to different values to simulate the fault of abnormal engine valve clearance, and obtained cylinder head vibration signals in normal and abnormal states separately, in order to do analysis in time domain. Also, this research decomposes the combustion excitation signals and the exhaust valve shut excitation signals through wavelet packet. The frequency bands of the excitation signals were determined by calculating the Root Mean Square (RMS) values of vibrational energy of reconstruction frequency bands. In order to achieve satisfying results, this research determine whether the valve clearance is normal or not, by comparing the RMS values.
2011, Vol. 30 
