Study About Monitoring System And Fault Diagnosis Based On LabVIEW And The Fractal Theory

This disquisition came from Hubei province Education Office's key item which named'Study on Fault Diagnosis Technology about Large Low-speed Over Loading Rolling Axletree'. The system is applied in certain steel mill to monitor the vibration state of the converter, which performs a good effect.The research fruit of'a Fault Diagnosis instrument for Large Low-speed Rolling Machine'has got the national patent. The patent's number is ZL200520095073X.The method about the fault diagnosis of large low-speed rolling axletree is analyzed in detail according to the present domestic and overseas research situation. It is illuminated how vibration signal is measured and the sensor is selected. An on-line monitoring system is developed with LabVIEW, and the detail diagnosis steps are analyzed.This paper is mainly consisted of three parts includes the introduction of rolling axletree's fault diagnosis method, the design of the monitoring system and the application of fractal theory in fault diagnosis. With a view of converter trunnion's vibration and the monitoring requirement, combine with the database technology, based on National Instrument's data acquisition card PCI6220 and some other hardware, the on-line monitoring system is developed with LabVIEW which is a graphic programming tool. After acquiring the real-time vibration signals, detail diagnosis steps are implemented. The time domain signal and the frequency spectrum are acquired to analyze the vibration's characteristic. While the Fractal and Chaos Theory is used for abstracting the eigenvalue, with which making the axes'complicated movement simplified to be a fractal dimension.