Research On Six-dimentional Vibration Isolation System Based On 2-dof Electromagnetic Actuator

China will complete the second phase of manned space station construction by 2020,initially establishing a space laboratory with short-term care,and plans to carry out cutting-edge experimental research in material life science,basic physics,life science,and biotechnology among which researches such as protein crystal growth,semiconductor manufacturing,combustion,and fluid mechanics need to be conducted in an ideal microgravity environment.Therefore,it is necessary to develop active vibration isolation technology for high microgravity.Based on the demand about active vibration isolation technology for high microgravity and the existing configuration of micro-vibration isolation platform and electromagnetic actuator,a six-dimensional vibration isolation platform based on the two degree-of-freedom electromagnetic actuator is proposed.Furthermore,using size constraints and mechanical performance requirement,the significant size of the vibration isolation platform is optimized after determining the structure of the vibration isolation platform.To verify whether the stiffness of the floating platform is large enough and the steady temperature distribution can meet the requirement,modal analysis and thermal simulation are carried out respectively.To establish an accurate dynamic model for the vibration isolation platform,the electromagnetic force/torque-current model of the vibration isolation platform is established by applying Lorentz force law after the derivation of the magnetic field distribution of the magnet array using the Fourier series method.Finally,the dynamic model of the vibration isolation platform is established according to the momentum and the angular momentum theorem of a rigid body.To realize the active control of the vibration isolation platform,it is necessary to obtain the floating platform's acceleration relative to the inertial frame and its pose relative to the base.Therefore,a six-dimensional pose calculation model and an acceleration calculation model of the vibration isolation platform are established respectively,and the controller used by dual closed-loop control system is constructed according to LQR(Linear Quadratic Regulator).