Abstract-To perform the ground simulation experiments of the complex space operations, this work proposes a new active magnetic suspension compensator. The large-gap magnetic suspension compensator (LGMSC) is a conceptual design for a ground-based experiment which could be used to investigate the technology issues associated with accurate suspended element control at large gaps. This compensator can be used as the out-of-plane electromagnetic actuator for the 3-DOF fine stage in certain high precision positioning applications. Based on the equivalent current method, we explain the basics of the magnetic suspension compensator and analyze its advantages. A gravity compensator has been realized in a test setup that shows the feasibility of the chosen modeling technique and of magnetic gravity compensation.

A dynamic Grey Wolf Optimizer (GWO) is proposed, noted as DGWO2, and a novel dynamic improved GWO algorithm is obtained after transferring the mutation operator and the eliminating-reconstructing mechanism to the DGWO2, noted as DMR-GWO2. A Type-2 fuzzy predictive compensation PID trajectory tracking controller based on the DMR-GWO2 is proposed to attain the tracking targets for the trajectory control of Par4 parallel robot. In the trajectory tracking controller, the DMR-GWO2 is designed for optimizing the Type-2 fuzzy logic controller which is in parallel with the PID controller to speed up the response of the parallel robot and to get the high adaptive capacity of the whole system. One input of the Type-2 fuzzy logic controller is the tracking error, while the other input is the sum of the derivative of the tracking error and the change rate of the expected angle. Finally, the experiments verify the effectiveness of the designed trajectory tracking controller and the tracking errors are small.