Study On Virtual Instrument For Condition Monitoring System Of Rolling Bearing

Vibration signals can reflect the operational status of the rolling bearing, therefore analyzing and monitoring vibration signals of the rolling bearing is an effective method for rolling bearing’s condition monitoring. Using virtual instrument technique could design professional instrument to satisfy condition monitoring requirements for rolling bearing. It also can realize the function of the advanced signal processing, which could be used for non-stationary signal analysis for acquiring running performance. Since virtual instrument is based on software, it is easy to update the instrument by modifying original function or adding new function. Each computer could be an instrument if the software is installed. So lots of money could be saved.Therefore, based on the study of condition monitoring methods for rolling bearing, a virtual instrument was designed for rolling bearing’s on-line condition monitoring and off-line analysis. The main work of the thesis is as follow:(1)Firstly, this paper introduces vibration signal characteristics. Through the analysis of the rolling bearing typical fault characteristic frequency, it knows the vibration characteristic in theory. Secondly, this paper introduces the bearing condition monitoring methods, including time-domain parameter analysis, Hilbert envelopment analysis and neural network intelligent diagnosis method. After that, the intelligent diagnosis method based on harmonic wavelet window and probabilistic neural network is described in detail. Train the neural network using feature vector extracted from simulation signal mixed noise under different states, and retrospective testing showed network designed well.(2)According to the virtual instrument development process, a virtual instrument was designed for rolling bearing’s condition monitoring. Firstly, this paper describes instrument requirements analysis, to determine the instrument function requirements. Secondly, based on requirements analysis, determine interface design and functional modules division for overall structural design, and then design the various functional modules, eventually forming a correct and efficient, good human-computer interaction capability virtual instrument. Finally, a variety of test cases were used to test the performance of the virtual instrument. And, the results show that the virtual instrument achieves the desired effect.(3)Applied to NSK626 rolling bearing experimental analysis, the results shows that the virtual instrument achieves the desired goals, and the virtual instrument is practicality.