Application Of Virtual Instrument In Bearing Vibration Measurer Based On LabVIEW

Rolling bearing is one of the important basic components of machinery, whose quality has a direct impact on the using quality and the life of the equipment. Bearing vibration measurer is a special instrument to evaluate the quality of bearings objectively by detecting the value of bearing vibration, which plays an important role in the entire bearing measurement link. The current mode of bearing measurement is as blow. Firstly vibration waveforms are detected by bearing vibration measurer, and then experienced operators evaluate the waveforms to determine the quality of bearings to be detected with their measurement experience. Therefore this method is inefficient and strongly dependent on the technical level of operators. And it has already been unable to meet the requirements of mass testing. Along with technological maturity of virtual instrument, it is hoped that this new technology will be gradually applied in bearing measurement field to get rid of difficulties mentioned above to achieve the goal of fast and efficient bearing measurement.In this paper bearing measurement system is established with a friendly interface and simple operations by virtual instrument LabVIEW programs based on the hardware of bearing vibration measurer. It has realized the calculation of RMS in separate frequency range, peak and P/R ratio, the display of vibration signal waveform in separate frequency range, the generation of signal spectrum, the description of quality distribution and other function for user interaction. Main research work of each chapter is outlined as following:In chapter II, the generation principle of bearing vibration noise is discussed from the perspective of the rolling classification, structure and working principle. It emphasizes the analyzing and summarizing of the generation and classification of bearing defects and the characteristics of the bearing defect detection waveform. The key technical parameters of bearing vibration signal in bearing measurement are determined with the composition, working principle and implementation function of bearing vibration measurer. Eventually, the concept of virtual instrument is introduced.In chapter III, the main function modules in bearing measurement system are specified from the perspective of the acquisition and implementation of the technical parameters of bearing vibration signal, which takes the virtual instrument as a starting point.Firstly, the concept, typical structure and development of virtual instrument are illuminated and the function characteristics and operation methods of virtual instrument software environment are also introduced here.Then, the realization of acquisition and processing functions and program procedures of bearing vibration signal are specified. In the bearing measurement system, bearing vibration signal will be collected by velocity sensor first. And then it will be amplified and filtered by an audio amplifier and ultimately be acquired and inputted into computer by DAQ data acquisition card for further analysis and processing. The analyses of vibration signal can be mainly divided into time-domain analysis, frequency-domain analysis and bearing grade judgment. And the achieved functions include the signal processing of separate frequency range, spectrum generation, RMS calculation, three-point detection and bearing grade judgment and etc.Finally, combined with the actual bearing measurement requirements, a measuring procedure is designed to meet the needs of different bearing types and different user's measurement standards. The import, increase, modification and storage of bearing information, judging standard and user input information are realized by data accessing to database. Event structure in LabVIEW is applied to receive user operating actions and response to them to realize the interaction between bearing measurement system and users. Meanwhile, the access to user bearing information, storage of waveform graph, saving and deleting of measurement data, running and halting of software system and system calibration are also implemented here.In chapter IV, the related parameters and technical indicators of bearing vibration measurer are discussed and the implementation methods of system functions are analyzed and the achieved effects and existed shortages are also pointed out. Contrasted with bearing vibration measurer, the composition of function modules and achieved effects of bearing measurement system based on virtual instrument LabVIEW are specified and the function improvement and new features development are indicated, too. Integrated with those function modules, taken S07907V-3A bearing vibration measurer as the standard measurement instrument, the designed bearing measurement system is tested under automation testing environment. In the end, the testing data are acquired and testing results are analyzed.