Research On Amplitude And Phase Measurement System Of Small Angular Vibration By Laser Interferometry

Combined with the Innovation Foundation of the State Key Laboratory of Fluid Power Transmission and Control of Zhejiang University "Research on Broadband and High Precision Angular Vibration Calibration Device", the amplitude and phase measurement system of small angular vibration by laser interferometry was researched in this paper.In chapter 1, the research background and significance was discussed. First, the concept of angular vibration sensor and the operating principle of calibration device were introduced. Secondly, the research status of laser measurement equipment and method of angular vibration at home and abroad was overviewed. Finally, the research purpose and contents of this paper were generalized.In chapter 2, the overall design scheme of amplitude and phase measurement system on small angular vibration by laser interferometry was presented. First, the principle of angular vibration measurement by laser interferometry and the theoretical basis of amplitude and phase measurement of angular vibration by sine approximation method were analyzed. Secondly, the overall structure of laser interference system for measuring amplitude and phase of small angular vibration, which was designed on the basis of the sine approximation method, was presented. Finally, the design contents and key elements of laser interferometer and the software for the upper computer were specified.In chapter 3, the design technique of the laser interferometer for measuring amplitude and phase of small angular vibration was researched. First, the improved design of the light path of the Michelson laser interferometer was introduced. Then the optical elements and their layout in the laser interferometer were presented, and the chuckings of the optical elements were designed. At last, the photoelectric conversion circuit was designed, in which the design methods of the signal conversion circuit, the power supply circuit and the signal amplifying circuit were analyzed, respectively.In chapter 4, the design technique of the software of the amplitude and phase measurement system of small angular vibration by laser interferometry was researched. First, combined with the system requirements, the overall software structure was designed. Secondly, combined with the function of the software, three software modules for hardware control, data processing and calibration were designed. And the working processes and programs for the communications of upper and lower computers, and the functions for resolving angular vibration signal were introduced. Finally, the simulation test for the software system was introduced, in which the capability of resolving the sine and non-sine angular vibration waveform were researched.In chapter 5, the experimental research on the amplitude and phase measurement system of small angular vibration by laser interferometry was introduced. After completing the debugging of the laser interferometer and the software, the amplitude frequency characteristic and phase frequency characteristic of an angular acceleration sensor and a circular grating displacement sensor were researched by the fringe counting method and the sine approximation method separately. Finally the measurement capability and uncertainty of the system were assessed.In chapter 6, the achievements of this paper were summarized, and the following research work was prospected.