An Ultra-Low Frequency Two DOFs’ Vibration Isolator Using Positive and Negative Stiffness in Parallel

With the improvement of performance in the ultra-precision manufacturing engineering, the requirements for vibration isolation have become increasingly stringent. In order to get wider effective bandwidth and higher performance of vibration isolation in multiple DOFs system, an ultra-low frequency two DOFs’ vibration isolator with positive and negative stiffness in parallel (PNSP) is proposed. The two DOFs’ isolator which combines a positive stiffness (PS) air spring with a negative stiffness (NS) magnetic spring in parallel and combines a PS flat spring with an NS inverted pendulum in parallel is designed to reduce the natural frequency and broaden the effective bandwidth in horizontal and vertical direction. Based on this structure, stiffness models of different components in different directions are established. Compared with a PS isolator, it possesses the characteristic of high-static-low-dynamic stiffness. The simulation curves also provide strong evidence. Last, a real-time active control system and a spectrum testing and analysis system are used for the contrast experiment between the mentioned PNSP structure and PS only. The experimental results demonstrate that the isolator with PNSP can obviously reduce the natural frequency to 1 Hz and simultaneously maintain the stability of the system and consequently verify the validity and superiority of the mentioned structure.

[1]  C. Seepersad,et al.  Analytical and Experimental Investigation of Buckled Beams as Negative Stiffness Elements for Passive Vibration and Shock Isolation Systems , 2014 .

[2]  M. Yasuda,et al.  Feedforward control of a vibration isolation system for disturbance suppression , 1996, Proceedings of 35th IEEE Conference on Decision and Control.

[3]  Michael J. Brennan,et al.  Static analysis of a passive vibration isolator with quasi-zero-stiffness characteristic , 2007 .

[4]  Yun-Ho Shin,et al.  Performance enhancement of pneumatic vibration isolation tables in low frequency range by time delay control , 2009 .

[5]  Kok Kiong Tan,et al.  Intelligent control of precision linear actuators , 2000 .

[6]  G. Akoun,et al.  3D analytical calculation of the forces exerted between two cuboidal magnets , 1984 .

[7]  Colin G. Gordon.  Generic vibration criteria for vibration-sensitive equipment , 1999, Optics + Photonics.

[8]  Michael J. Brennan,et al.  On the design of a high-static-low-dynamic stiffness isolator using linear mechanical springs and magnets , 2008 .

[9]  Eric H. Anderson,et al.  ELITE-3 active vibration isolation workstation , 2001, SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring.

[10]  Yuji Ishino,et al.  A three-axis vibration isolation system using modified zero-power controller with parallel mechanism technique , 2011 .

[11]  Michael J. Brennan,et al.  Active vibration isolation of a system with a distributed parameter isolator using absolute velocity feedback control , 2010 .

[12]  David J. Wagg,et al.  Dynamic Analysis of High Static Low Dynamic Stiffness Vibration Isolation Mounts , 2013 .

[13]  Ben S. Cazzolato,et al.  Theoretical design parameters for a quasi-zero stiffness magnetic spring for vibration isolation , 2009 .

[14]  Xuedong Chen,et al.  Integrated hybrid vibration isolator with feedforward compensation for fast high-precision positioning X/Y tables , 2010 .

[15]  M. Takasaki,et al.  Vibration isolation system combining zero-power magnetic suspension with springs , 2007 .

[16]  M. O. Tokhi,et al.  Active Vibration Control of Flexible Plate Structures with Distributed Disturbances , 2012 .

[17]  P. M. Alabuzhev,et al.  Vibration protecting and measuring systems with quasi-zero stiffness , 1989 .

[18]  Wenjiang Wu,et al.  Analysis and experiment of a vibration isolator using a novel magnetic spring with negative stiffness , 2014 .

[19]  Alexey Zotov,et al.  Designing of Compact Low Frequency Vibration Isolator with Quasi-Zero-Stiffness , 2015 .