Chaotic motion and control of a tethered-sailcraft system orbiting an asteroid

摘要

Chaotic motion and control of tethered-sailcraft system orbiting an asteroid is examined. A sailcraft is hanged at the end of the tethered satellite system which can be utilized for asteroid exploring missions. The highly irregular shape of the asteroids can lead to complex motions of the system. The dynamics of in-plane libration is established using the Lagrangian equation method with the harmonic coefficients C-20 and C-22 of the gravity field of the asteroid. In addition, we use the Melnikov method to analytically predict the occurrence of chaos. This paper focuses on the influence of eccentricity, orbital radius and tether length on the libration characteristics of the tethered system. The time history of libration, the phase plane, the Poincare section and power spectral density (PSD) are presented numerically for verifying the validity of the Melnikov method in predicting occurrence of chaos. Besides, numerical simulation results indicate that larger eccentricity, smaller orbit radius and longer tether length can make the system more chaotic, i.e., the chaotic layers will become thicker. To show the effect of variation of eccentricity on the libration characteristics, a corresponding bifurcation diagram is given. In order to avoid chaotic motions causing uncertainties and high risks, we propose a chaos control method of inerter-damper for the tethered-sailcraft system. Finally, numerical simulation results verify the effectiveness of the proposed chaos control method. (C) 2019 Elsevier B.V. All rights reserved.