High-precision Identification Technology Of Residual Moment For Satellite Activity Load

With the complexity of the space mission,the structure of the load on the satellite is becoming more and more complex.In the working process,the activity load will produce residual moment,which will affect the control accuracy of the satellite,and then affect the stability of the satellite attitude.If the residual moment of the load can be measured,the residual moment can be introduced to analyze the control algorithm of the satellite,so as to reduce the influence of the residual moment on the satellite attitude.In this context,aiming at the problem that the residual moment produced by the activity load affects the satellite attitude,this paper studies the high-precision identification technology of the residual moment on the ground,analyzes the residual moment identification algorithm of ground,establishes the residual moment identification system of ground,and studies the residual moment identification algorithm of the satellite in orbit,It provides an effective measurement method for the residual moment produced by the activity load.In this paper,firstly,the attitude kinematics model of spacecraft is studied,the identification model of moment of inertia and residual moment of three-axis air bearing platform are given,and the processing method of attitude data in ground physical simulation is analyzed,which provides data support for ground identification of residual moment of activity load.The orbit dynamic model of spacecraft is further studied,and the identification model of residual moment of spacecraft in orbit is given,which provides theoretical support for the identification of residual moment in orbit.The detailed residual moment measurement method is given,which provides a reference for the application of the following algorithm and the design of the actual system.Then,the identification algorithm of the moment of inertia of the three-axis air bearing platform is studied,and the identification algorithm of the moment of inertia based on the least square method,recursive least square method and fading memory method is given.The selection method of the excitation signal in the identification process of the moment of inertia of the three-axis air bearing platform is analyzed,and the frequency range and waveform requirements of the excitation signal are given.The step-by-step measurement method is studied to measure the residual moment,and the step-by-step measurement algorithm based on the identified mathematical model of three-axis air bearing platform is given.The joint identification method for measuring residual moment is studied.The joint identification algorithm of residual moment and moment of inertia of three-axis air bearing platform based on fading memory method and gradient descent method is given.The influence of different algorithms on the accuracy and speed of residual moment identification is compared.The feasibility of residual moment identification method is analyzed theoretically.Then,the residual moment identification system of ground is designed,the structure and work flow of the system are given,the software scheme of the system is designed,and the software structure and implementation method of the system are given.With the help of the physical simulation system of the actual three-axis air bearing platform,the residual moment identification algorithm is tested.The practical feasibility and identification accuracy of the residual moment measurement algorithm are analyzed,and the effect analysis of the residual moment measurement algorithm in the satellite simulation system of ground is given.Finally,the residual moment measurement algorithm is extended to the earth oriented spacecraft.The control system model of the spacecraft in orbit motion is analyzed,the identification model of the spacecraft in orbit motion is given,the identification algorithm of the residual moment of the activity load on the spacecraft is analyzed,and the application method of the residual moment identification algorithm in the working condition of the spacecraft in orbit motion is given.The identifiability of the residual moment of the activity load in the process of spacecraft motion in orbit is analyzed,and the identifiable conditions of the moment of inertia and the residual moment of the spacecraft are given,which further expands the application scope of the residual moment identification algorithm.