Development of a three-axis active vibration isolation system using zero-power magnetic suspension

A three-axis active vibration isolation system using zero-power magnetic suspension was developed. A mathematical model of the apparatus was derived for discussing the control system. It was shown that the three motions could be treated separately and, in addition, each dynamics was represented in a similar form. The condition for the system to have infinite stiffness for direct disturbance was derived. This characteristic was confirmed experimentally. It was also demonstrated that the transmissibility characteristics from the floor to the isolation table were not worsened by introducing zero-power control.