Control analysis for a contactless de-tumbling method based on eddy currents: problem definition and approximate proposed solutions
In AIAA Guidance, Navigation, and Control Conference, (AIAA SciTech-2016), 04.1.-08.1.2016, San Diego, California, o.A., pages 1-25, Jan/2016. American Institute of Aeronautics and Astronautics. ISBN: DOI: 10.2514/6.2016-0642.
Zusammenfassung (Abstract) :Existing active debris removal (ADR) methods that require physical contact with the target have applicability limitations depending on the maximum angular momentum that can be absorbed. Therefore, a de-tumbling phase prior to the capturing phase may be necessary. The aim of this article is to present the on-going work on the control mod- ule of a contactless de-tumbling subsystem based on eddy currents (`Eddy Brake'). This research is being carried out in the framework of the Agora mission (Active Grabbing & Orbital Removal of Ariane), which employs a robotic spacecraft concept to demonstrate technologies to autonomously de-tumble, capture and de-orbit an Ariane rocket body. The article frst presents the `Eddy Brake' method and the Guidance, Navigation and Control (GNC) architecture of a chaser spacecraft. Furthermore, the linear and rotational dynam- ics based on the Magnetic Tensor Theory (MTT) are explained. Then, a control strategy is presented to keep a constant relative distance between the two objects and a suitable relative pointing of the coil towards the target object. A simplified analytical solution for the control of the two objects in the 2D problem is presented and the stability of the system in the vicinity of a stable asymptotic state is analysed. Finally, two case studies are presented on the Ariane-4 H10 and Ariane-5 EPS upper stages.