An Adaptive Approach to Vision-based Formation Control

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Date
2003-08Author
Sattigeri, Ramachandra J.
Calise, Anthony J.
Evers, Johnny H.
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Show full item recordAbstract
In considering the problem of formation control in the
deployment of intelligent munitions, it would be
highly desirable, both from a mission and a cost
perspective, to limit the information that is transmitted between vehicles in formation. However,
the lack of information regarding the state of motion
of neighboring vehicles can lead to degraded
performance and even instability. This paper presents
an adaptive output feedback approach for addressing
this problem. We design adaptive formation
controllers that allow each vehicle in formation to
maintain separation and relative orientation with
respect to neighboring vehicles, while avoiding
obstacles. The method works by enabling each
vehicle in the formation to adaptively correct for the
effect that the motions of neighboring vehicles have
when regulating relative variables like range and line
of sight. It is assumed that estimates of these
variables can be derived using passive, vision-based
sensors. The need for explicit communication to
maintain formation is minimized and the resulting
controller solution is decentralized. We implement a
reactive obstacle avoidance controller to navigate in
an environment with obstacles. The formation
controller and obstacle avoidance controller are
outer-loop controllers whose outputs are speed and heading commands. These commands are blended
together to generate composite speed and heading
commands that are inputs to the inner-loop controller.
The weights used for blending the commands depend
upon the priority of the task at hand. We illustrate the
method with an example involving a team of three
aircraft keeping formation in the presence of
obstacles.