Self-Alignment Capability Analysis and Self-Attraction Dipole Solution of Spacecraft Electromagnetic Docking

Abstract

Spacecraft electromagnetic docking has many potential advantages, such as no propellant consumption and plume contamination, while providing high-precision, continuous, reversible, synchronous, and noncontacting control capabilities. With these advantages, there are strong dynamic nonlinearity and coupling, which are not friendly to controller design. Electromagnetic actuation has capabilities of force/torque symmetry and self-alignment, which could be exploited not only to simplify the controller but also to reduce the demand of relative motion measurement and improve control precision. In this paper, based on the theoretical derivation of nonlinear relative motion dynamic models, the magnetic force/torque symmetries and the self-alignment capability are analyzed, and then the self-attraction magnetic dipoles are solved. In addition, several numerical simulation cases are given to verify these capabilities and dipole solutions.