摘要：A 4×4 matrix model with three degrees of freedom
is proposed as a means for controlling microvibrations and
applied to an electromagnetic isolator. The model was derived
from an assumption based on small- and low-frequency vibrations.
The coordinates of the 3 DOF was composed of the 4 variables,
representing a vertical position, pitch, roll, and a proof term.
The coordinates were calculated from the 4 position sensors
in the isolator and formulated into a 4×4 matrix, which
possesses inversive full rank. The electro-magnetic isolator was
built for a simulated machine in semiconductor manufacturing
and consisted of a heavy surface plate, sensors, amps, a controller,
and air springs with electromagnets. The electromagnets are
installed in a pneumatic chamber of the individual air spring.
The performance of the 3 DOF model was experimented and
compared with that of a 1 DOF model in an impact test. The
settling time in the result was reduced to 25%.
