Study On Actuators Of Active Payload-level Vibration Isolation System For Experiments In Space

Disturbances from crew motion and other mechanical disturbers can cause exceedance of the microgravity acceleration, especially at low-frequency, required by experiments in space. Therefore, the payload needs to be isolated from the low frequency off-board disturbances by active vibration isolation system. Actuators are the key components of the system to achieve the special microgravity requirements. Studies on active payload-level vibration isolation system are made in foreign countries, including MIM and g-LIMIT, which have been proved to meet the design requirements by flight test or application. However, studies on this field remain blank in China.The thesis is a part of the study on active payload-level vibration isolation system for experiments in space. Considering the features of space application and the needs of study, the thesis makes a systematical study on actuators of active payload-level vibration isolation system for experiments in space by simulations and tests. First, the parameters target of the actuator is calculated according to the general requirements of the active vibration isolation system. Then various structural forms are designed, grounded on the theory of magnetic suspension, and the merits and demerits of each form are concluded. The structural form with better comprehensive properties is selected. After that phase, design of magnetic circuit, finite element simulation to verify the design and coil parameter design of actuator are made to the selected structural form. Based on calculations and simulation results, stepwise improvement designs are made to get a better design to meet the needs of actuators parameters requirements. Next phase is performance simulation of the design, which can present the trends of key parameters requirements of actuators under different relative positions and currents. Finally, the test system is designed to testify the performance parameters of actuators and the results of the test are made. Moreover, the test results are analyzed to verify the design parameters and check the simulation model.The test results show that the moving range of actuator is±10mm; the weight is 494g; when the thrust force reaches 3N, the current is 1.7A, the current density is 6.42 A/mm2, and the power dissipation is about 30W; 3dB bandwidth is about 180Hz. The results fulfil the basic design demands of active vibration isolation system and they lay a foundation for the Second Phase Project of Manned Space Flight in china.