%0 Conference Proceedings
%F Cui15a
%A Cui, L.
%A Marchand, E.
%A Haliyo, S.
%A Régnier, S.
%T Hybrid Automatic Visual Servoing Scheme using Defocus Information for 6-DoF Micropositioning
%B IEEE Int. Conf. on Robotics and Automation, ICRA'15
%P 6025-6030
%C Seattle, WA
%X Direct photometric visual servoing uses only the pure image information as a visual feature, instead of using classic geometric features such as points or lines. It was demonstrated efficiently in 6 degrees of freedom (DoF) positioning. However, in micro-scale, using only image intensity as a visual feature performs unsatisfactorily in cases where the photometric variation is low, such as motions along vision sensor's focal axis under a high magnification. In order to improve the performance and accuracy in those cases, an approach using hybrid visual features is proposed in this paper. Image gradient is employed as a visual feature on z axis while image intensity is used on the other 5 DoFs to control the motion. A 6-DoF micro-positioning task is accomplished by this hybrid visual servoing scheme. The experimental results obtained on a parallel positioning micro-stage under a digital microscope show the robustness and efficiency of the proposed method
%U http://rainbow-doc.irisa.fr/pdf/2015_icra_cui.pdf
%U http://dx.doi.org/10.1109/ICRA.2015.7140044
%8 May
%D 2015