| Summary: | 碩士 === 國立臺灣大學 === 機械工程學研究所 === 100 === In order to minimize and simplify the interferometer as a practically useful sensor in industrial use, we use a versatile interferometric module as the core of our sensor. By applying the polarizing theory and four-detector-array, the performance of the sensor can be optimized. Combined with polarizing beam splitter, quadrant detector and transmission grating, the system havs wavelength compensation and it can measure the pitch error and yaw error. This research also presents a general scheme of signal processing by mixing a hardware circuit and a software algorithm, proceeding pre-correction, real-time compensation, wave count and interpolation of the metrology signal.
This multi-degrees-of-freedom laser encoder included Michelson interferometer, autocollimator and wavelength compensator. Calibrated with NMM, the accuracy and the measurable range of the three displacement sensor are better than 32 nanometers. The measureable range can be reach to 50 millimeters in one direction. The angular accuracy of the autocollimator is ±0.3 arcsec in static measurement and ±0.7 arcsec in large linear motion measurement. In ±2°C , with the implantation of wavelength compensator, the error of the wavelength is reach to〔(△λ)/λ〕=10E-6 .
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