Jacobian, manipulability, condition number and accuracy of parallelrobots

Although the concepts of jacobian matrix, manipulability and condition number have been floating around since the early beginning of robotics their real significance is not always well understood. In this paper we re-visit these concepts for parallel robots and exhibit some surprising results (at least for the author!) that show that these concepts have to be manipulated with care for a proper understanding of the kinematics behavior of a robot