Summary: | 碩士 === 國立臺灣大學 === 機械工程學研究所 === 104 === Recently, the optical fiber sensors, especially the fiber Bragg grating (FBG) sensors, have been rapidly developed due to the advantages such as excellent mechanical properties, thin geometries, high sensitivity and electromagnetics immunity. It can be applied to static analysis by demodulating the FBG central wavelength or dynamic measurement by power modulated system, and both of them can measure multiple points in the same time with wavelength division multiplexer. FBG sensors measuring systems were developed in our laboratory and this thesis is going to use these techniques to measure industrial machine tools.
The main object of this research is focused on the application of FBG on measuring signals of built-in high-speed spindle and high-presicion surface grinding machine. In the beginning, we used FBG to measure the surface of the spindle, to analyze its vibration signal, and obtained its rotating speed by frequency domain. Then, we tried different methods, such as using thermal grease and Teflon tube, in order to ensure that FBG only measured temperature changes. Further, we used a nude FBG and a tube FBG to measure the spindle simultaneously and developed a method to decouple the signals of vibration, temperature change and thermal deformation. Also, we embedded FBG inside the spindle since the diameter of the fiber grating is small, so that we can use FBG to monitor the inside message of the spindle. In addition, we designed a customized system by using SLD broadband light source, light coupler and CWDM for the spindle measurement to make the FBG measuring system become a commercial product with low price and small size. We also measured the high-presicion surface grinding machine, including including the circumstances in which the spindle was not cutting, and in which the spindle is cutting the workpiece. By measuring the dynamic signals of spindle and the workpiece, we obtained complete information about patterns and changes in cutting period, also achieve he purpose of monitoring the operation of the machine tool and cutting.
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