Small Satellite Electromagnetic Docking System Modeling and Control

There is a growing need for interplanetary travel technology development. There are hence plans to build deep space human habitats, communication relays, and fuel depots. These can be classified as large space structures. To build large structures, it is essential that these are modular in nature. With modularization of structures, it becomes essential that interconnection of modules is developed. Docking systems enable interconnection of modules. The state-of-the-art technology in docking systems is the Power Data Grapple Fixture (PDGF), used on the International Space Station by the Canadarm2 robotic arm to grapple, latch onto and provide power to the object it has grappled. The PDGF is operated by highly skilled astronauts on the ISS and are prone to human errors. Therefore, there is a need for autonomous docking. Another issue with the PDGF is that it costs around 1 to 2 million US dollars to build the 26-inch diameter docking mechanism. Hence, there is a growing need to build a lower cost and scalable, smaller docking systems. Building scalable smaller docking systems will hence enable testing them on small satellites. With the increasing need for small, low cost, autonomous docking systems, this thesis has been proposed. This thesis focuses on modeling and autonomous control of an electromagnetic probe and cone docking mechanism. The electromagnetic docking system is known to be a highly nonlinear system. Hence, this work discusses various control strategies for this docking system using a levitation strategy.