Autonomous Mission Management for Spacecraft Rendezvous Using an Agent Hierarchy
Mark Jackson, Christopher N. D’Souza, Hobson Lane · Infotech@Aerospace · 2005
An agent based autonomous mission manager for spacecraft is developed and applied to a spacecraft rendezvous problem. The mission manager monitors, plans and executes rendezvous activities for a chaser satellite with low thrust and high thrust effectors. The software is based upon a hierarchy of “Activity Agents,” each of which plans, monitors, executes and re-plans an activity. These activity agents are instantiated and scheduled by a software framework capable of reconfiguring the agent hierarchy when re-planning occurs. Targeting and planning algorithms are incorporated into the agent hierarchy to orchestrate a rendezvous with an orbiting spacecraft. These algorithms make use of low thrust guidance to arrive in the neighborhood of the target, followed by a series of high thrust burns to arrive at a specified offset point at a specified time. During both the low thrust and high thrust activities, the mission manager monitors subsystem status as well as the relative navigation state of the chaser. When low thrust failures occur, the manager completes the rendezvous by scheduling additional high thrust burns. The mission manager, along with low and high thrust guidance algorithms, is implemented in simulation. A demonstration of several re-planning events – both failure, and error driven - is provided with three dimensional graphics as well as an “agent activity” display which depicts the active agents, and shows the hierarchy reconfiguration process when re-plans occur.