Study On Measuring Techniques And Dragging Device For Windpipe And Wire In Developing Urtra-Low-Frequency Vibrator Calibration System

In this dissertation, RMS, distortion measuring and dragging device for windpipe and wire were studied in order to develop the calibration system of ultra-low frequency standard vibration system, which was associating with a National Scientific Infrastructure Platform Project - "Building of National Ultra-low Frequency Standard Vibration Device" and a projet from China Earthquake Administration - "Research on ultra-low frequency standard vibration system for calibration of seismometer".In chapter 1, the aims and significance of the dissertation were presented. First, the present research status and developing trend on techniques of vibrator calibration at home and abroad were introduced. Then, the present research status and developing trend on measuring techniques of RMS and THD and servo system for long-stroke ultra-low frequency vibrator calibration system were presented. In the end, the main research aim and content of the dissertation were addressed.In chapter 2, RMS measuring technique of ultra-low frequency base on searching-peak method was researched. First, the principle of RMS measurement base on searching-peak method was expatiated. Then, the software and hardware design of RMS measurement were analyzed.In chapter 3, the digital distortion measurement of ultra-low frequency base on LabVIEW was researched. First, the principle of digital distortion measurement based on LabVIEW was expatiated. Then, the software and hardware design of the system were analyzed.In chapter 4, a long-stroke dragging device for windpipe and wire was researched. First, technical parameters of dragging device were addressed according to motion characteristics of ultra-low frequency vibration table. Then, controlled-motor and motion rail of servo system were chosen according to its parameters. In the end, control scheme of servo system was expatiated.In chapter 5, the research contents of the dissertation were tested. The test includes: the RMS measurement of ultra-low frequency based on searching-peak method, the distortion measurement of ultra-low frequency based on LabVIEW, and the long-stroke dragging device for windpipe and wire. And the errors were analyzed. In chapter 6, the achievements of the dissertation were summarized and the further research work that needs to be done was put forward.