A system that provides a base stabilization system for controlling motion
of a controlled structure. The system includes a ground structure such as
the floor of a fabrication facility and the controlled structure includes
a base on which equipment is mounted. The system also includes at least
three air mounts and a plurality of actuators all attached to the ground
structure and to the base to isolate the base from the ground structure
and to stabilize the base. The system includes a plurality of position and
acceleration sensors each of which are co-located with a corresponding
actuator. The system also includes a multi-input, multi output feedback
control system comprising a computer processor programmed with a feedback
control algorithm for controlling each of the actuators based on feedback
signals from each of the sensors. The co-location of the sensors with the
actuators avoids serious problems resulting from higher order vibration
modes.