Research On Several Technology Problems Of Low Frequency Laser Vibration Measuring System In The Field Of Vabration Quantifivation

On the basis of practically achieved Low-Frequency Laser-Vibration Measuring-System, this thesis analyses the principle of Laser-Vibration Measuring-System, the optical factors which have effect on contrast degree of interference fringe, the optical-electric transformation factors which have effect on measuring accuracy, the important of filter for improving the accuracy in the absolute calibration and the outward vibration which has effect on system accuracy, etc.In chapter one, the background of laser measuring vibration, and then followed by its current status, is introduced and analyzed. The importance of laser measuring vibration in metrology is presented. The problems about how to improve the measuring accuracy of system are analyzed, and thus the aim and task about the thesis are determined.In chapter two, the principle of absolutely calibrating is presented. Two kinds of interference measurement methods are introduced: counting of frequency ratio method and Bessel function method, and the accuracy of the two methods are analyzed.In chapter three, the importance of maintaining the equal optical path between measuring beam and reference beam in measuring horizontal and vertical vibration table are analyzed, and the factors having effect on contrast degree of interference fringe are introduced. For improving the accuracy of Laser-Vibration-Measuring-System, the phase-modulation-multi-period-average method and the vibration isolated ofsystem are analyzed.In chapter four, the principle of the optical-electric transformation is presented. Based on the demands of the system, the filter circuit are designed. Using the simulation of Pspice software, the working efficiency and quality of active filter circuit design is improved. Using the simulation of Pspice software, the working efficiency and quality of active filter circuit design is improved. The results of experiment verified the simulation of Pspice software.In chapter five, the technology requirements of vibration calibration system are introduced, and thus the optical and electric design are realized. The Laser-Vibration-Measuring-System is tested and the results are analyzed. At last, the error of the Laser-Vibration-Measuring-System is analyzed. The results of experiment verified the simulation of Pspice software.In chapter six, the important research work of this thesis are systematically summarized, and the whole research results and some problems under to study in future are put forward.