Numerical Control Lathe Tool’s Wear And Breakage On-line Monitoring With Virtual Instrument

The tool wear and breakage monitoring technology is helpful in prolonging machine tool’s service life, improving the mechanical processing quality, reducing machine tool failure time, improving the manufacture efficiency, and enhancing the processing automation. Virtual instrument has great programming convenience and strong function, and is very flexible, especially in the case of synthesis measurement, data processing and graphic displaying.In this paper, the virtual instrument based on LabVIEW is selected as the researching tool. The advantages of virtual instrument are made the best use of. The characteristic signal which responses the wear and breakage state is sampled and analyzed, and then the tool state is educed properly.The work done in this paper is as follows:●Based on the background of the topic, the commonly used tool state monitoring methods and the characteristics of virtual instrument are introduced, and the significance of this paper’s research is discussed.●Based on the research of the reasons, forms, process and damage standard of tool wear and breakage, the cutting force signals are selected as the monitoring characteristic signals.●The data acquisition hardware system is established. Vertical octagonal loop three-component resistance turning dynamometer with parallel configuration is used to acquire three-component cutting forces. Amplifying and filter circuits are designed and the transformation of analog signals to digital signals is realized through data acquisition card.●The software of the monitoring system is designed on LabVIEW. The sub-modules include password entering module, cutting force empirical formula value inquiring module, data acquiring module, dynamometer calibrating module, neural network module, tool state on-line monitoring module and data replaying and analyzing module.●Simulation experiments of dynamometer calibrating module, neural network module, tool state on-line monitoring module are conducted, and the experiment results are analyzed.Finally, summary and forecast of this paper’s work are provided.