Patent ID: 6286644
Filing Date: 2001-09-11
Classification: F16F,G03F

Abstract:
An active vibration isolator comprising:a vibration isolation platform on which an object to be isolated from vibration is mounted;an air-spring actuator which supports said vibration isolation platform, said air-spring actuator including a valve, which is subjected to feedback drive;vibration measurement means which measures vibration of said vibration isolation platform and outputs acceleration and velocity signals;position measurement means which measures position of said vibration isolation platform;a first feedback loop for feeding back an output of force measurement means, which measures a working force applied by said air-spring actuator to said vibration isolation platform, thereby controlling the working force applied by said air-spring actuator;a second feedback loop, having a PI compensator, wherein signals of said vibration measurement means are fed back to an input side of said PI compensator, for producing damping and spring effects which act upon said vibration isolation platform; anda third feedback loop for feeding back an output from said position measurement means, thereby positioning said vibration isolation platform at a designated position.