Gregory Frey

Project: Coordinated Constrained Control of Spacecraft Formations

Work Description: I am interested in developing methods for spacecraft relative motion planning with obstacle avoidance. My work mostly focuses on developing methods which use simple dynamics models and techniques such as graph search which lead to simple and fast calculations which may be implementable on-board a satellite. Previous work has included the design and theoretical analysis of several parameter governor controllers which can be used to initialize and maintain a formation of spacecraft while satisfying state and control constraints, and development of several methods to generate safe trajectories for use in satellite inspection missions. I am currently working on a relative motion planning scheme which exploits Natural Motion Trajectories (NMTs) and invariance to generate relative motion trajectories which satisfy thrust-limit constraints and avoid exclusion zones using graph search on a "virtual net" with nodes (vertices) corresponding to NMTs.