System Integration and Control Design of a Maglev Platform for Space Vibration Isolation

Abstract: 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.