1. Hebei Province Key Laboratory of Heavy Machinery Fluid Power Transmission and Control, Yanshan University, Qinhuangdao, Hebei 066004, China
2. Heavy-duty Intelligent Manufacturing Equipment Innovation Center of Hebei Province, Yanshan University, Qinhuangdao, Hebei 066004, China
Abstract:Aiming at the fact that the vibration signals of hydraulic pumps have the characteristics of nonlinear, non-stationary and low signal to noise ratio, a feature extraction method based on complete ensemble empirical mode decomposition and fuzzy entropy integrated is proposed. Firstly, the vibration signals of the hydraulic pump are decomposed into several intrinsic mode functions by means of complete ensemble empirical mode decomposition. Secondly, the correlation coefficients between each intrinsic mode function and the original signal are calculated, and the components with higher correlation coefficients are selected to obtain their fuzzy entropies, then the degradation characteristics are obtained. Finally, taking the measured data in different degradation states of hydraulic pump as an example, the variable predictive model based class discriminate method is used to verify the effectiveness of the proposed feature extracted method. The experimental results show that the method has higher precision in extracting the hydraulic pump degradation characteristics, and the accuracy rate of degenerate state identification is increased to 100%.
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