"Stabilization of coupled orbit–attitude dynamics about an asteroid uti" by Yue Wang and Shijie Xu

Article Title

Stabilization of coupled orbit–attitude dynamics about an asteroid utilizing Hamiltonian structure

Authors

Yue Wang, School of Astronautics, Beihang University, Beijing 100191, China
Shijie Xu, School of Astronautics, Beihang University, Beijing 100191, China

Keywords

asteroid missions, gravitationally coupled orbit–, attitude dynamics, full dynamics, stabilization, non-canonical Hamiltonian, structure, potential shaping

Abstract

The gravitationally coupled orbit–attitude dynamics, also called the full dynamics, in whichthe spacecraft is modeled as a rigid body, is a high-precision model for the motion in theclose proximity of an asteroid. A feedback control law is proposed to stabilize relativeequilibria of the coupled orbit–attitude motion in a uniformly rotating second degree andorder gravity field by utilizing the Hamiltonian structure. The feedback control law isconsisted of potential shaping and energy dissipation. The potential shaping makes therelative equilibrium a minimum of the modified Hamiltonian by modifying the potentialartificially. With the energy-Casimir method, it is theoretically proved that an unstablerelative equilibrium can always be stabilized in the Lyapunov sense by the potential shapingwith sufficiently large feedback gains. Then, the energy dissipation leads the motion toconverge to the relative equilibrium. The proposed stabilization control law has a simpleform and is easy to implement autonomously, which can be attributed to the utilization ofnatural dynamical behaviors in the controller design.