Adaptive Guidance and Control for Autonomous Formation Flight

Autonomous formation flight is a mechanism for achieving a pre-specified formation between a group of unmanned aerial vehicles. This paper presents an approach to autonomous formation flight in a leader-follower configuration using an adaptive output feedback control technique. Using measurements of the line-of-sight range and angles, an adaptive guidance law is formulated for the follower that generates velocity commands so that the follower maintains a prescribed range from the leader in the presence of leader maneuvers. A method to integrate the guidance system with the adaptive trajectory following autopilot controller of the Georgia Tech helicopter UAV is also studied. The overall architecture for autonomous formation flight is evaluated using software-in-theloop simulations. Simulation results show that the proposed adaptive formation controller for helicopter UAVs maintains good range tracking performance in the presence of leader maneuvers. I. Introduction Formation control of multiple unmanned aerial vehicles (UAVs) has attracted significant attention from the UAV research community. The objective of formation control is to obtain a group of autonomous agents to move together in a desired formation and accomplish desired tasks such as reconnaissance, surveillance and precision strike. To complete such tasks without human intervention and in the presence of large external disturbances or flight critical failure, one of the problems of particular interest to researchers has been the automatic control of a group of UAVs flying in close formation. Most of the research done in the recent past has focused on the coordination and station-keeping of multiple UAVs so as to maintain the relative separation and orientations between the UAVs in the formation and to track desired flight trajectories. In most autonomous formation flight (AFF) designs, communications between UAVs in formation is required. In general, information about a vehicle in formation is broadcast to the entire group or only to the adjacent vehicles in close proximity. Recently, many dierent approaches to communication for formation control are introduced. If an active communication

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