【摘 要】
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This paper proposes a fuel-optimal deorbit scheme for space debris deorbit using teth-ered space tug.The scheme contains three stages named respectively as dragging,maintenance and swinging.In the first stage,the tug,propelled by continuous thrust,tows de
【机 构】
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School of Astronautics,Beihang University,Beijing 100191,China
论文部分内容阅读
This paper proposes a fuel-optimal deorbit scheme for space debris deorbit using teth-ered space tug.The scheme contains three stages named respectively as dragging,maintenance and swinging.In the first stage,the tug,propelled by continuous thrust,tows deorbit to a transfer orbit with a tether.Then in the second stage,the combination of the tug and the debris flies unpow-ered and uncontrolled to a swing point on the transfer orbit.Finally,in the third stage,the tug is propelled at the swing point and the rotation speed of the tethered system increases such that the debris obtains enough velocity increment.The trajectory optimization of the first stage is estab-lished considering the total fuel consumption of the three stages,whereas the dynamic model is sim-plified for computation efficiency.The solution to the optimal problem is obtained using a direct method based on Gauss pesudospectral discretization.Then a model predictive controller is designed to track the open-loop optimal reference trajectories,reducing the states\' deviations caused by model simplification and ignorance of perturbations.Furthermore,it is proved that the fuel-optimal swing point is the apogee of the transfer orbit.The paper analyzes the fuel con-sumption of a typical scenario and demonstrates effectiveness of the proposed deorbit scheme numerically.
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