Determination of 3-D pose of a flexible object by stereo matching of curvature representations

For automatic handling of a flexible object such as an electric wire, cable or rope it is necessary to determine the 3-D pose of the object. However, it is difficult to achieve this because of the intrinsic flexibility of the flexible object. We use the k-curvature representation to describe the skeleton image of a flexible object. Moreover, we present two fast stereo matching methods to determine the pose for automatic handling. The one is based on a least square error method and the other is based on the interpolation between curvature extrema. At first, we need to calculate the curvatures of object skeleton images which are taken through two cameras. We apply our algorithms to these two calculated curvature representations. We execute computer simulations to evaluate the validity of the presented algorithms. The results give us some guidelines for the applications with hand-eye robots. Finally, we carry out a camera calibration process for a linear lens model and an experiment to determine the pose of a coaxial cable with the calibrated camera parameters