Abstract:Taking the pneumatic diaphragm control valve airtightness fault as the research object, the Hilbert-Huang transform of the control valve position action signal is first performed, and the occurrence and occurrence time of the fault are detected by the empirical mode decomposition method; The modalities and their energy proportions of various modes are used to obtain on-line diagnosis of the class and intensity of the airtightness of the pneumatic control valves. The simulation and solid valve experiments verify the validity and practicability of the detection and diagnosis methods proposed in this paper. For the first time, the Hilbert-Huang transform signal analysis method was introduced into the fault diagnosis of non-periodic and non-stationary processes, and the detection, diagnosis, and strength identification of the air-tightness faults in the pneumatic control valve chamber were completely realized.