Abstract
The range of applications using microvibration isolation equipment is being extended even to devices for which the influence of vibration was not previously considered. As a representative example, the application of an active microvibration isolation equipment with an air spring actuator, suitable for MRI and NMR that operate in a strong magnetic field, is examined. For use in a strong magnetic field, the active microvibration isolation equipment needs to have an actuator made of a nonmagnetic material. The servo valve that controls air pressure in the actuator, however, must be installed away from the strong magnetic field because it cannot be fabricated from a nonmagnetic material. This necessitates a long air supply tube to connect the servo valve to the actuator. Since this long tube affects the actuator characteristics, adequate vibration isolation performance cannot be attained with a controller designed using the conventional equipment model. In this study, a new equipment model is proposed by analyzing the characteristics of the active microvibration isolation equipment, and the control system is designed for the model using the model matching technique. The equipment model and control technique are validated by simulation and experiments.
