Research On Micro-satellite Formation Control By Using Aerodynamic Forces

Nowadays the technique of micro-satellite is more and more maturesin the research of technology and it is the hot topic among aerospacepowers. Significant breakthrough in the astronautics and aeronautics hasbeen caused in reducing the payload and decreasing the powerconsumption by the technique of micro-satellite, especially for militaryreconnaissance and so on. However, the life of the micro-satellite will bedecreased notably by aerodynamic force in the low earth orbit (LEO) orultra low orbit. In order to complete the LEO micro-satellite spacemissions, effective measures must be taken to overcome the adverse effectscaused by aerodynamic forces. Therefore, an issue of satellite formationflight control by using aerodynamic force and moment is proposed in thispaper.First, the aerodynamic model of plates was established based on therarefied gas dynamics theory and the mechanical properties in the freemolecular flow were also analyzed. The results provide a theoretical basisfor the optimal configurations of the actuators.Second, considering the high-fidelity J2equations a set of nonlinearrelative dynamics which is appropriate for the method of differentialaerodynamic force was derived. Moreover, micro-satellite formationreconfiguration was accomplished by switching the six configurations ofaerodynamic plates and achieved by conducting in-plane and out-of-planemaneuvers in sequence. Simulation results shows verified the feasibility ofthe presented modified relative dynamics based on the Matlab and restrainthe effect of J2perturbation. Third, this paper presented long-term continuous control strategy byusing differential aerodynamic forces for the satellite formation keepingproblem by improving the configurations of actuators. A Lyapunov-basedcontroller was designed with high accuracy during the satellites formationflight. Simulation results show that the presented Lyapunov-basedcontroller is capable of accomplishing the satellite formation keeping inthe presence of errors.Finally, this paper proposed a passive control strategy by usingaerodynamic moment for the satellite coordinated attitude control problem.A variable structure controller with the proof of global stability usingLyapunov theory was presented under control input saturation. A drivecontrol law of actuators was designed by the process of inversedlinearization. Simulation results show that the variable structure controlleris valid for LEO satellite coordinated attitude control problem.