Active vibration isolation system having pressure control

摘要

An active vibration isolation system includes a pneumatic control system and an electronic control system. The pneumatic control system supports a mass sensitive to vibration and isolates the mass from high frequency external disturbances. The electronic control system isolates the mass from low frequency external disturbances. The pneumatic control system includes a compliance chamber filled with a fluid to pneumatically support the mass, apparatus for directly measuring a pressure level in the compliance chamber, and apparatus for controlling the pressure level to minimize the effects of pressure variation in the compliance chamber. The measuring apparatus includes an instrument to measure an absolute pressure level of the compliance chamber or an instrument to measure a differential pressure level between the compliance chamber and a reference chamber having a predetermined pressure level.