The Research And Analysis Of Hydraulic Line Crack Fault To Real-time Monitor

In the actual hydraulic system, the malfunction is always occurring about on hydraulic line.if the crack of the hydraulic pipeline can not be identified in time, a small cracks usually be accumulatedand become a large one which threaten the entire line, and even the entire hydraulic system at last. So it is positive for maintenancing pipeline crack for security of the whole hydraulic system.In order to realize the function of data acquisition, this paper uses the current popular hardware development platform —Arduino which is a kind of open source hardware development platform, combined with the corresponding hardware, through programming and debugging, the author finally achieve the integration of data acquisition card. through homemade square wave signal generator practical verification,the reliability and validity of the data acquisition card are proved. A virtual instrument based on LabVIEW is designed for controlling the data acquisition card.it has a set of functions such as real time display, DAQ, data upload, data preservation.through signal generator practical verification, the effectiveness of the homemade data acquisition system is demonstrated.In this paper, the real-time monitoring of vibration signal of hydraulic pipeline is studied. Combined virtual instrument technology and homemade data acquisition system,a vibration test system of hydraulic pipeline is builded up.through simulation or emulation of the working state of the hydraulic pipe crack,the homemade data acquisition system is used to collect the vibration signal of the pipeline with crack or without crack.Comparing the normal working state of hydraulic pipeline with abnormal,through a series of traditional and modern signal analysis theory which used in this paper called HHT by LabVIEW and MATLAB.the author finally gets the characteristics of fault state of hydraulic pipeline.The research shows that the fourier transform can not effectively analyze and process the vibration signal of the hydraulic pipeline, which shows that the fourier transform had a set of application limitations in Nonlinear non-stationary signal.Compared with fourier transform, the HHT which is adaptability for the signal local analysis, is good at analyse locale of signal. It also embodies the advantages of Hilbert-Huang transform in the analysis of nonlinear and non-stationary signals,maded up for the inadequacy of fourier transform. The Hilbert-Huang transform has a good adaptability to complicated signal, which also reflects the superiority of Hilbert-Huang transform in the analysis of nonlinear and non-stationary signals.through the HHT, we find a reliable and efficient method of theoretical analysis and judgment for pipe crack identification, it has a good practical significance.