Research On Key Technologies Of Satellite Ground Physical Simulation System

With the successful first flight of the Long March 5B Launch Vehicle at 18:00 on May 5,2020,my country is one step closer to successfully building its own manned space station.The development of aerospace technology and satellite technology is limited by the satellite itself and the cost of launching and maintenance.The application of new aerospace technology must pass the heavy verification of the ground simulation verification system,especially the satellite ground full physical simulation system based on the three-axis air bearing table.Is increasingly valued by R&D personnel in the aerospace field.The three-axis air bearing table is the core equipment of the satellite ground full physical simulation system.The three-axis air bearing table relies on the air ball bearing to counteract gravity when it floats.It has very little friction and friction torque and is used to simulate the satellite in orbit.Special micro-interference dynamic environment.The rotational inertia,attitude control and center of mass balance of the three-axis air bearing table are the key technologies for the satellite ground full physical simulation system to carry out the test work normally.This paper focuses on the above key issues and conducts research on the development of the satellite ground full physical simulation system.It has important research significance and practical value.First,it summarizes the current development and research status of the three-axis air bearing table research,rotational inertia measurement,attitude control and balance adjustment at home and abroad,and analyzes the research achievements of researchers in the world in the field of satellite ground all-physics simulation systems.Then,the kinematics equations and dynamics equations of the three-axis air bearing table are established by the direction cosine matrix,Euler angle,quaternion and the rigid body angular momentum theorem.Secondly,based on the dynamic model of the three-axis air bearing table,the mathematical model of the three-axis air bearing table system to be identified is given.By establishing the Simulink simulation model of the three-axis air bearing table system,the angular velocity of the fiber optic gyro and the reaction flywheel are output,and the rotational inertia of the three-axis air floating table based on the system identification algorithm of the general least square method and the recursive least square method are given respectively.The identification method verified the effectiveness of this method by mathematical simulation.Then,the problem of attitude control of the three-axis air bearing table is studied.Based on the established dynamics equations of the air-floating table,the attitude control method of the three-axis air bearing table based on the classic PID control algorithm is given,and its performance is analyzed by mathematical simulation.Considering the interference that may be encountered during the actual operation of the three-axis air bearing table,the H? control algorithm of the mixed sensitivity of the three-axis air bearing table was designed and mathematically simulated to improve the control performance of the attitude control and the robustness of the system.Finally,the balance adjustment problem of the three-axis air bearing table is studied.A balance adjustment algorithm based on recursive least squares method for identifying gravity eccentricity moment is proposed.By online identification of the gravity eccentricity moment of the three-axis air bearing table,the slider of the linear module is controlled to move to achieve the purpose of automatic balance adjustment.And a balance adjustment algorithm based on the flywheel angular velocity curve is given.According to the rising or falling slope of the flywheel angular velocity curve,the gravity eccentricity of the air float can be obtained indirectly,and the purpose of automatic balance can also be achieved.Finally,the effectiveness of the method is verified by simulation.