Study On Orbital Control Of Separation And Formation Flying In Space

This paper presents the research on Sub-satellite orbital control problem after ejections. First of all, I assume Sub-satellite ejected from Main satellite by spring, and then progressive orbit transition under the control system, and engender formation flying finally. The main problem is the section of Sub-satellite orbit transition. Because the control force of Sub-satellite is incomplete, it require to design a control law, which could make Sub-satellite trace Main satellite, engender formation flying and satisfy requirements of engineering projects finally. This paper presents the relative motion equation between Sub-satellite and Main satellite, and split flying process into two parts: Free flight phase and Control flight phase, and then use quadratic type optimal control methods to design the control law of Sub-satellite orbit transition. In the orbit dynamics equations, control force is continued, but in engineering projects use we constant thrust control, so we need use PWPF method. And meanwhile, it conducts a comparison of the two conditions. The first condition is that the control force is complete. In such cases, Sub-satellite may achieve formation flying speedily by the control law, and could satisfy requirements of engineering projects. Secondly, in the Sub-satellite orbit plane, there are three directions control force in body-coordinate axis. In such cases, Sub-satellite may achieve formation flying by the control law also, and could satisfy requirements of engineering projects, but the time is increased. At the end of this article, it gives perturbation analysis for formation flying, and discover that major perturbative force in low earth orbit could make influence for the formation flying.