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Volume 26 Issue 7 - Publication Date: 1 July 2007
 
Visual Servoing for Nonholonomically Constrained Three Degree
of Freedom Kinematic Systems
 
G. A. D. Lopes University of Michigan, currently a visiting student at the University of Pennsylvania and D. E. Koditschek Electrical & Systems Engineering, University of Pennsylvania
 
This paper addresses problems of robot navigation with nonholonomic motion constraints and perceptual cues arising from onboard visual servoing in partially engineered environments. A general hybrid procedure is proposed that adapts to the constrained motion setting the standard feedback controller arising from a navigation function in the fully actuated case. This is accomplished by switching back and forth between moving “down” and “across” the associated gradient field toward the stable manifold it induces in the constrained dynamics. Guaranteed to avoid obstacles in all cases, conditions are provided under which the new procedure brings initial configurations to within an arbitrarily small neighborhood of the goal. Simulation results are given for a sample of visual servoing problems with a few different perceptual models. The empirical effectiveness of the proposed algorithm is documented by reporting results of its application to outdoor autonomous visual registration experiments with the robot RHex guided by engineered beacons.
 
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