Attitude Dynamics of Electric Sail from Multibody Perspective

作者:Liu, Fei; Hu, Quan*; Liu, Yufei
来源:Journal of Guidance, Control, and Dynamics, 2018, 41(12): 2633-2646.
DOI:10.2514/1.G003625

摘要

The electric sail is an innovative propellantless propulsion concept that gains continuous momentum from the solar wind. In this work, the electric sail's attitude dynamics is established from a multibody perspective. Firstly, the dynamics of a single charged tether is described by a dumbbell model. Comparisons with an elastic multipoint model show that the dumbbell model is simpler and accurate enough to describe the motion of tether when the spin rate meets a specific lower bound. Then, the electric sail's attitude dynamics model is established through Kane's method based on the dumbbell model of the tethers. Finally, a case study is performed for the electric sail. It is shown that a 4-kmradius electric sail with 12 tethers of which the voltage is 25 kV could provide the sailcraft with a characteristic acceleration of 0.1 mm/s(2). The results also indicate that the satellite bus's acceleration oscillates with the undiminished out-of-plane swing of the electric sail, in which the period and amplitude are in inverse proportional to the spin rate and its square, respectively. Besides, a dynamical equilibrium point for system's attitude exists when the electric sail is perpendicular to the solar wind. The presented work offers a basic referential model for the real-time feedback control problems of the electric sail's attitude.