Research On Key Technologies Of High-precision Satellite High-precision Control

With the increased investment and development of the national aerospace industry,the research level of various aerospace key technologies is increasing day by day,and the large-scale satellites and the diversification of flexible structures are the general trend.The traditional rigid body control method is difficult to meet the design requirements,and may even cause the system to oscillate and cause huge losses.Therefore,the study of the control method for large flexible satellites has important research significance.This paper has carried out research on various aspects of attitude maneuver control of flexible vibration,and the research content mainly includes the following aspects:Firstly,the research status in this field at home and abroad is analyzed,and then for the characteristics of large flexible satellites with large flexible components and small central rigid bodies,a global modal modeling method using Hamilton principle is given to establish the dynamics of the controlled object The model has a more accurate model structure;in view of the additional impact of the vibration suppression actuators and sensors installed on the satellite on the dynamic model of the system,an electromechanical coupling model has been established to supplement and improve the dynamic model and obtain Electromechanical coupling model of large flexible satellite.Based on the electromechanical coupling model established above,the system parameter identification method is studied.This paper first studies the parameter identification method based on the recursive least square method,and obtains the most accurate parameters in the statistical sense according to the experimental data.However,this method has a large error in the presence of process noise and measurement noise,and it is difficult to obtain accurate parameters.It is necessary to preprocess the experimental data.Therefore,this paper immediately studied Kalman filtering,filtered the common measurement noise in engineering,and obtained an unbiased estimate of the state quantity,combined with the least squares method to obtain an unbiased parameter estimate,and verified the effectiveness of the method through simulation Sex.Then,for the vibration suppression of large flexible satellites,the layout optimization of multiple actuators was studied.Firstly,several criterion functions for layout optimization are analyzed.Observable performance indicators and minimum output energy indicators are used to derive corresponding criterion functions and analyze their physical meanings.Then,using these two criterion functions as fitness functions,on the basis of genetic algorithm,an optimization method of actuator layout based on improved genetic algorithm is given,and finally the corresponding optimal number of actuators and optimal installation are obtained The installation scheme of the location,and the feasibility of the algorithm was verified by simulation.Finally,for the attitude maneuver control process of the large flexible satellite,based on the system parameter model and actuator installation position obtained from the above research,the maneuver control problem of the large flexible satellite is studied.Including variable structure control and model-free control that does not depend on the actual model.First,the variable structure control with active vibration suppressor is studied.The variable structure control has strong robustness,but considering that the various modal state quantities of flexible vibration cannot be measured,it is difficult to achieve the full state feedback required by conventional design methods,so In this paper,the design method of the variable structure controller based on output feedback is given,and the simulation shows that the controller suppresses the flexible vibration,and achieves a good maneuver control effect.Because there is a certain gap between the theoretical modeling and the real model,this paper studies the model-free control method,the design process does not depend on the accurate system model,and the effectiveness of the above method is verified by simulation.