Study On High Stabilization Staring Attitude Control Method Of Small Video Satellite

Small video satellite is a new kind of earth observation satellite.Compared with the traditional earth observation satellite,its biggest advantage is that it can stare at a ground area and realize continuous observation of the area for a long time.Satellite staring imaging is the main mode of small video satellites,satellite attitude control system through real-time adjustment of the attitude of the satellite,so that the optical axis of the optical sensor is always aligned with the ground area for continuous camera.At present,there is little research on the issue of satellite staring attitude control for small video satellites.There are many technical problems to be solved.This paper mainly studies high stabilization staring attitude control method of small video satellite.The main contents and achievements of this paper are as follows:The basic characteristics of video satellites on ground staring are studied.The influence of the imaging angle on the field of view and resolution of the video satellite is analyzed.The requirements of the satellite attitude control stability index satisfying the high quality imaging requirements are put forward.Aiming at the problem of unclear geographic location in the video scene,this paper establishes the relationship between the direction of the field of view and the true geographical orientation,and designs a staring attitude change rule that can specify the pointing direction of a certain field of view,The middle field of view can always be oriented along a given geographic azimuth.In the case of limited control torque,the PD controller is prone to overshoot and can't achieve fast tracking in the process of satellites adjusting from any initial attitude to stable staring state on the target region.A new Fast Staring Attitude Tracking Control Algorithm based on improved Cascade-Saturation control is put forward.And the shortest path maneuvering strategy with rotation around the Euler axis makes the maneuver path shortest and no overshoot occurs in the control process.Finally,based on the constraint of the angular velocity of the maneuvering process,the fast staring control with angular velocity limit is deduced law.Aiming at the mission planning requirements of video satellite for multiple target points,a task planning method of multi-index optimization staring observation based on hybrid two-level coded genetic algorithm is proposed.A mathematical model of task planning is established,and an optimization objective function which integrates the observation time index,the observation time window equilibrium and the imaging resolution index is designed,and an adaptive genetic algorithm is designed to solve the task planning model.The observation order and the observation time window which make the objective function optimal are obtained.Aiming at the problem that the target tracking attitude is needed in the conventional attitude tracking control,it is difficult to track the unknown moving object accurately.A high stability tracking control method based on image feedback is proposed.The mathematical model of image information processing is established.The attitude tracking can be carried out by using the coordinates of the moving object in the image plane position coordinates and calculating the attitude deviation as the feedback quantity.This method can make the satellite track high-speed target,and the stability is better than the conventional attitude tracking method.