Parallel-mechanism based vibration isolation system using displacement cancellation control

A vibration isolation system based on parallel-mechanism is developed. The responses of the developed system against a disturbance are investigated analytically and experimentally. The developed system consists of six individual vibration isolation units of single degree-of-freedom which are placed in parallel between a common vibration isolation table and base; consequently, the common vibration isolation table has six-degrees-of-freedom motions to be controlled by the units. The individual units are fabricated based on series combination of two isolators that use magnetic suspension. The two series connected magnetic suspensions in each unit are controlled according to displacement cancellation principle; one of them behaves as a displacement cancellation isolator and the other behaves as a positive stiffness isolator.