Early Fault Diagnosis of High Pressure Diaphragm Pump Check Valve Based on VMD-HMM

The fault signal of the large-sized reciprocating high-pressure diaphragm pump check valve is relatively weak, and it is difficult to identify the early wear breakdown failure, early stuck valve fault and normal state vibration signal, An early fault diagnosis method for check valves based on the combination of variational mode decomposition(VMD) and hidden markov model(HMM) is proposed. Firstly, the check valve vibration signals of different states are subjected to variational mode decomposition, and then the different features of each layer of IMF components are extracted to form a feature vector set, and vector quantization processing of feature vector sets. Then, multiple HMM models are trained by selecting feature quantities in different states. Finally, the feature quantities of the test samples are input to different HMM models. In the middle, the check valve fault type is determined by comparing the log likelihood probability values. The experimental results show that the method can effectively identify the fault type of the check valve, and the accuracy rate reaches 96.0%.