Dynamic Analysis and Test of a Space Micro-vibration Simulator Based on 6-Dimensional Parallel Mechanism

To reproduce the multi-dimensional micro-vibrations generated by the operation of on-board equipment, such as reaction wheel, a space micro-vibration simulator based on the Gough-Stewart platform is proposed, and the dynamic characteristic of the micro vibration simulator is studied.Firstly, the dynamic model of the micro-vibration simulator is derived by Newton-Euler's method, in which the quality of the legs and the hinge and the eccentricity of the load center are included.Combining with the principle of virtual work, the generalized stiffness, damping and mass matrices of the system are presented, and the mathematical analytic formula is derived to calculate the natural frequency and the main vibration mode of the micro vibration simulator.Then, the modal analysis of the simulator is carried out by the finite element method and theoretical model, and the first six natural frequencies and modal shapes of the system are obtained.The simulation results reveal that the results obtained by theoretical model and the finite element are in good agreement.Finally, the stiffness and the natural frequencies of the simulator are tested.The test result indicate that the maximum error between natural frequencies obtained by the theoretical model and finite element analysis and the test results is less than 5%, which demonstrates that the theoretical model is valid.The natural frequencies and mode shapes of the space micro-vibration simulator are obtained, providing a basis for the subsequent design and test.