%0 Journal Article %F Comport05c %A Comport, A.I. %A Marchand, E. %A Chaumette, F. %T Complex articulated object tracking %J Electronic Letters on Computer Vision and Image Analysis, ELCVIA, Special issue on "Articuled Motion & Deformable Objects" %V 5 %N 3 %P 20-30 %I ELCVIA %X In this paper new results are presented for tracking complex multi-body objects. The theoretical framework is based on robotics techniques and uses an a-priori model of the object including a general mechanical link description. A new kinematic-set formulation takes into account that articulated degrees of freedom are directly observable from the camera and therefore their estimation does not need to pass via a kinematicchain back to the root. By doing this the tracking techniques are efficient and precise leading to real-time performance and accurate measurements. The system is locally based upon an accurate modeling of a distance criteria. A general method is given for defining any type of mechanical link and experimental results show prismatic, rotational and helical type links. A statistical M-estimation technique is applied to improve robustness. A monocular camera system was used as a real-time sensor to verify the theory %U http://rainbow-doc.irisa.fr/pdf/2005_elcvia_comport.pdf %U http://doi.org/10.5565/rev/elcvia.103 %8 May %D 2005