Simulation Of Satellite Flyingaround Other Aerocraft Usingair-bearing Simulation System

As the continously exploring the space, more and more spacecrafts likesatellites have been launched into the space. Because of the complex systems, thetesting and mainteance have become very important and difficult. But the missionflying around the spacecraft can be done easily by the satellite. Flying around thespacecraft is the relative movement between the spacecraft and the small satellitewhich make the particular spacecraft as the center. This movement can monitor thespecial space targets repeatability, which provide the important information for thespace activities, such as monitoring ontrack, rendezvous and docking and formationflying,etc. Simulation system on the ground can simulate the actual movement of thesatellite, test its controller and verify the stability and accuracy. This thesis designsthe position and attitude controllers for the five degrees of freedom air-bearingplatform to make it fly around a hypothetical target.Firstly, A brief introduction is provided to the various components of ADRCcontroller and their principles. The mathematical model of air-bearing platform andits actuators(jet thruster and reaction wheel) is established in the correspondingcoordinate system. The result of simulation shows that the air-bearing platform hasthe specialty of strong non-linear and the coupling in attitude and orbit movement.Secondly, The position controller is designed for the five degrees of freedomair-bearing platform. The ADRC is applied to single channel translation of flyingaround movement, and then improve the controller for its shortcomings. The resultshows the improved controller can make the air-bearing platform reach the desiredposition in the shortest time. Then the disturbance in the translational movement isanalysed, and the simulation result with the disturbance reveals the improvedcontroller satisfies the request of single channel translation.Thirdly, The position and attitude controllers for the air-bearing platform isdesigned. First, the attitude controller for jet thruster is designed and the disturbancein the attitude movement.is analysed. The simulation result shows that the attitudesof air-bearing platform can reach the desired position quikly. Then the controller isdesigned for the flywheel, and the data shows that control accuracy of the flywheelis higher than the jet thruster. After that, a control redundancy allocation strategy isdevised for the jet thruster and flywheel that is using the jet thruster when theangular error is large, using the jet thruster and flywheel in the same time when theangular error is middle and using the flywheel when the angular error is small.Finally, the difficulty of the double channels translation of flying around movementis presented. The decoupling the controller make the air-bearing platform fly around the hypothetical target successfully.At last, the simulation verifies the feasibility and control accuracy of theposition and attitude controller. The result shows that the controller can overcomethe couplings between the each two channels for the platform, and it can accomplishthe task of flying accurately.