  Micro-vibration has been a dominant factor impairing the performance of
scientific experiments which are expected to be deployed in a micro-gravity
environment such as Spacelab. The micro-vibration has a serious impact on
scientific experiments requiring a quasi-static environment. Therefore, we
proposed a maglev vibration isolation platform (MVIP) operating in six degrees
of freedom (DOF) to fulfill the environmental requirements. In view of
non-contact and large stroke requirements for micro-vibration isolation, an
optimization method was utilized to design the actuator. Mathematical models of
the actuator's remarkable nonlinearity were established so that its output can
be compensated according to floater's varying position and the system's
performance may be satisfied. Furthermore, aiming to adapt to an energy-limited
environment such as Spacelab, an optimum allocation scheme was put forward.
Considering the actuator's nonlinearity, accuracy and minimum
energy-consumption can be obtained simultaneously. In view of operating in six
DOF, methods for nonlinear compensation and system decoupling were discussed,
the necessary controller was also presented. Simulation and experiments
validate the system's performance. With a movement range of 10x10x8 mm and
rotations of 200 mrad, the decay ratio of -40 dB/Dec between 1-10 Hz was
obtained under closed-loop control.
