Distribued estimation architectures and algorithms for formation flying spacecraft

摘要

Future formation flying missions are being planned for fleets of spacecraft in MEO, GEO, and beyond where relative navigation using GPS will either be impossible or insufficient. To perform fleet estimation for these scenarios, local ranging devices on each vehicle are being considered to replace or augment the available GPS measurements. These estimation techniques need to be reliable, scalable, and robust. However, there are many challenges to implementing these estimation tasks. Previous research has shown that centralized architecture is not scalable, because the computational load increases much faster than the size of the fleet. On the other hand, decentralized architecture has exhibited synchronization problems, which may degrade its scalability. Hierarchic architectures were also created to address these problems. This thesis will compare centralized, decentralized, and hierarchic architectures against the metrics of accuracy, computational load, communication load, and synchronization. It will also briefly observe the performance of these architectures when there are communication delays.