Libration control of bare electrodynamic tether for three-dimensional deployment

Abstract

Various promising applications of electrodynamic tether have been proposed for space missions over the past decades. A crucial issue of these missions is to deploy an electrodynamic tether under a rapid and stable state. This paper aims to stabilize the libration motions of a bare electrodynamic tether during its three-dimensional deployment. The tethered system under consideration consists of a main-satellite and a sub-satellite connected to each other through a bare electrodynamic tether. A widely used dumbbell assumption considering the tether as rigid and inflexible is adopted to facilitate the dynamic modeling and analysis of the tethered system. A pair of active control laws is synthesized by simultaneously regulating the electric current and tether tension to achieve an efficient stabilization of the three-dimensional libration of the bare electrodynamic tether in the deployment process.

Nonlinear deformation and attitude control for spinning electrodynamic tether systems during spin-up stage

“…The spinning motion of E-sail was studied by Du et al, who concluded that tether flexible tether motion is an essential factor in the stability of spinning tether systems [21]. Electrodynamic forces provide a propellant-less source of energy for SEDT maneuvers and attract focus from scholars [22][23][24].…”

“…Coefficient sat  should be relatively larger to attenuate disturbance. ( ) i fx is the hard saturation function, , i M S = indicates two saturation functions in(22)…”

Dynamic Analysis and Libration Control of Electrodynamic Tether for Reboost Applications

“…The study of Zhong shows that the libration dynamics and stability of EDT system is a key issue and regulated electric current in the tether to stable the libration motions [21]. Luo and Chen have developed the libration motions of EDT system by regular the tether current and length during the tether deployment [22], [23]. Li used a high fidelity multiphysics model of the EDT system for libration and transverse motion control of the system [24].…”