Active low-frequency vertical vibration isolation system for precision measurements

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• 作者：Kang Wu ; Gang Li ; Hua Hu ; Lijun Wang
• 关键词：vibration isolation ; vertical ; low frequency ; active
• 刊名：Chinese Journal of Mechanical Engineering
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：30
• 期：1
• 页码：164-169
• 全文大小：
• 刊物主题：Mechanical Engineering; Theoretical and Applied Mechanics; Manufacturing, Machines, Tools; Engineering Thermodynamics, Heat and Mass Transfer; Power Electronics, Electrical Machines and Networks; Elec
• 出版者：Chinese Mechanical Engineering Society
• ISSN：2192-8258
• 卷排序：30

文摘

Low-frequency vertical vibration isolation systems play important roles in precision measurements to reduce seismic and environmental vibration noise. Several types of active vibration isolation systems have been developed. However, few researches focus on how to optimize the test mass install position in order to improve the vibration transmissibility. An active low-frequency vertical vibration isolation system based on an earlier instrument, the Super Spring, is designed and implemented. The system, which is simple and compact, consists of two stages: a parallelogram-shaped linkage to ensure vertical motion, and a simple spring-mass system. The theoretical analysis of the vibration isolation system is presented, including terms erroneously ignored before. By carefully choosing the mechanical parameters according to the above analysis and using feedback control, the resonance frequency of the system is reduced from 2.3 to 0.03 Hz, a reduction by a factor of more than 75. The vibration isolation system is installed as an inertial reference in an absolute gravimeter, where it improved the scatter of the absolute gravity values by a factor of 5. The experimental results verifies the improved performance of the isolation system, making it particularly suitable for precision experiments. The improved vertical vibration isolation system can be used as a prototype for designing high-performance active vertical isolation systems. An improved theoretical model of this active vibration isolation system with beam-pivot configuration is proposed, providing fundamental guidelines for vibration isolator design and assembling.