Electromagnetic Formation Control Using Frequency Multiplexing

This dissertation addresses control of relative positions and orientations of formation flying satellites using magnetic interactions. Electromagnetic formation flight (EMFF) is implemented, in which each satellite is equipped with a set of electromagnetic coils to generate an electromagnetic field. Traditional EMFF technique applies DC magnetic fields which lead to a nonlinear and highly coupled formation dynamics that allow for only position or orientation control of the satellites. We present a new frequency multiplexing method, which is a technique that uses multi-frequency sinusoidal controls, to approximately decouple the formation dynamics and to provide enough controls for both position and orientation control. Next, we develop a new decentralized EMFF strategy for controlling the relative positions and the relative orientations of the satellites, simultaneously. In addition, we address the problem of optimal control allocation. Analysis, numerical examples, and experimental demonstrations are used to validate the effectiveness of the control strategy