Rule-based formation estimation of distributed Spacecraft

This paper addresses an estimation problem specific to formation flying of spacecraft that can be approached with rule or logic based methodologies. A decentralized and self-centered framework of the estimator is formulated and shown to be a feasible estimation architecture under formation reconfiguration or formation member failures. A rule-based strategy is applied to the problem that switches the gain of the linear observer of the formation. Each gain set is derived from a constant gain linear observer optimized for either formation member acquisition or steady state operation. The formation member acquisition time can be critical when considering a dynamic formation reconfiguration followed by precision pointing required by scientific mission. This particular strategy has the advantages of onboard computational efficiency and fast filter convergence during formation initialization or formation member acquisition. A two-spacecraft simulation analysis was performed to demonstrate and validate the efficacy of the algorithm.