Distributed coordination and control of formation flying spacecraft

Abstract

Formation flying is a key technology for many planned space missions that will use multiple spacecraft to perform distributed observations. This paper extends pro vious work on the design of a highly distributed formation flying control system that uses linear programming to determine minimum fuel trajectories for the spacecraft to remain within some specified tolerance of their “desired points”. The primary contribution of this paper is that it presents a direct procedure for calculating the fleet reference point (called the virtual center) that can be used to determine the desired states for each vehicle in the fleet. The calculation of this virtual center is based on measurements available from the relative navigation sensing system (carrier-phase differential GPS) developed for this application. The selection of the reference point includes a weighting on fuel use across the fleet, which facilitates increased coordination and cooperation within the decentralized control system. Full nonlinear simulations are presented to demonstrate the reduction in fuel use that can be obtained with this improved cooperation.