Mamoru Shimazaki

Comprehensive Active Microvibration Control Systems Using Piezoelectric Actuators for Base-Isolated Precision Manufacturing Facilities

Active microvibration control is expected to be applied to floors and even entire buildings of precision manufacturing facilities to meet requirements for more perfect vibration-free environment in the facilities. It is desirable that such facilities are effectively protected from earthquake attacks by using seismic isolation. For base-isolated precision manufacturing facilities, comprehensive active microvibration control systems were studied to control both of microvibrations born in the inside due to equipment and human walks and microvibrations coming from the outside due to ground vibrations and winds. A base-isolated 2-story building model of a 3m×5m×4mH external size and a 6.9t total mass was used for experiments, in which 4 multistage rubber bearings and a viscous shear damper were installed for the seismic isolation, while 20 piezoelectric actuators were attached to the columns and the beams and 8 piezoelectric actuator units were installed in the seismic isolation layer for the active control. The tests showed that the system consisting of the passive base-isolation system and the piezoelectric actuators attached to the columns and the beams could most effectively control the three-dimensional microvibrations due to the external and the internal disturbances.