Research On Attitude Of Leo Small Satellite Control Method To Earth

With the continuous development of science and technology,so that satellite miniaturization is possible.Micro-satellite development and launch cost is not high,can make human more convenient to explore information.Therefore,it is necessary to study the attitude measurement and control of microsatellite.Firstly,in this paper,the relationship of coordinate transformation in the satellite attitude determination and description of Satellite Attitude are studied.Then the kinematic equation based on quaternion method satellite is deduced and studied the dynamics equations of satellite.Finally,posture positioning need posture sensor model is studied.Secondly,the methods of informant in satellite attitude and the attitude determination method of star sensor and solar sensor is studied.In this paper,the state estimation method is used to determine the attitude of the satellite.The extended Kalman filter(EKF),the unscented Kalman filter(UKF)and the adaptive Kalman filter are studied.The influence of the error of the fiber optic gyroscope on the attitude positioning accuracy is analyzed.Then the attitude measurement of the star sensor based on the EKF filter is designed.The simulation results show that the simulation accuracy of the EKF algorithm is higher than that of the UKF algorithm.In order to solve the low frequency error of the star sensor,a multi-model adaptive filter is designed to meet the requirements.Thirdly,the stability of the decentralized PID control system of inertial momentum wheel of inertial actuator in the control system is studied.The momentum wheel is modeled and a robust controller is designed to ensure the stability of the momentum wheel.Finally,the idea of the combined network of micro-satellites is proposed,and its orbit-based orbit determination model based on satellite-to-satellite;the control scheme and simulation of the micro-satellite are designed.