Flexible object handling based on a reconfigurable parallel kinematic structure - PARAGRIP
In recent years, manufacturing industry is governed by fundamental changes with regard to the conditions, like progressive globalization and rapid technological development as well as changes in the resources situation. Classical demands on handling systems are currently undergoing changes. In the present situation priorities are increasingly shifting towards customized production and flexible solutions to component dependent problems. A focus on individualist production with versatile and flexible packaging-, assembly- and handling systems helps to solve the dilemma between economic productivity and product variance.
A novel handling system was developed at the IGM, as a cost-effective approach for component dependent problems. A modular and versatile design offers a fast and easy adaption of the kinematic structure to fulfill the requirements of changing handling tasks. The main idea of this handling principle is based upon autonomous gripping and moving objects by using multiple arms within a parallel kinematic structure. Whenever the grasping is done, the parallel kinematic robot structure is regenerated and integrates the object within this robot structure as a moveable platform. The object can then be moved freely in space with the degree of freedom F=6, like a conventional parallel kinematic manipulator.
By breaking up the classical border between robot and gripper this concept features a higher flexibility, needed to manipulate objects of different shapes and large scale components. The adaption to changed component geometry is done automatically by choosing the contact points, where the joining of arm and object is done.
Additionally the arms can be relocated on the base. The combination of contact points and arm base points have a major influence on motion characteristics, for e.g. workspace, accuracy and stiffness as well as the transmission of forces and velocity on the drives.
The system configuration can be adapted or changed even during object motion by dynamically re-grasping the object with additional arms. A graphical user interface with algorithms for system self-optimization supports the user to plan the motion and configuration. Because the robot arms are designed to work together, a simplified and more economic actuator concept is possible. This leads to a mobile and lightweight layout. The handling concept was developed at the IGM, by passing through the phases: conceptual design, structural synthesis, dimensional synthesis, design, construction and test. A first prototype was realized, with the friendly support of Stöber Antriebstechnik
This novel handling concept is enhanced, in collaboration with the laboratory of Machine Tools and Production Engineering at RWTH Aachen University, within the scope of the cluster of excellence ICD D-3.2 „Reconfigurable and Self-Optimising Handling System“ and is proved with a second prototype.
The department of mechanism theory and dynamic of machine thanks Stöber Antriebstechnik, Pforzheim Germany, and the German Research Foundation (DFG) for their friendly support.
Paragrip in RWTH insight:
 Nefzi, M; Riedel, M.; Corves, B.: Development and Design of a multi-fingered Gripper for Dexterous Manipulation. In: Mechatronic 2006, 4th IFAC-Symposium on Mechatronic Systems. September 12–14, 2006, Heidelberg.
 Riedel, M.; Nefzi, M.; Hüsing, M.; Corves, B.: An Adjustable Gripper as a Reconfigurable Robot with a Parallel Structure. Second International Workshop on Fundamental Issues and Future Research Directions for Parallel Mechanisms and Manipulators, September 21–22, 2008, Montpellier, France.
 Müller, R.; Corves, B.; Hüsing, M.; Esser, M.; Riedel, M.; Vette, M.: Rekonfigurierbares selbstoptimierendes Bauteilhandling. In: 8. Kolloquium Getriebetechnik Aachen 2009. Verlagshaus Mainz, Aachen, 2009. ISBN: 3-86130-984-X. S. 297-311.
 Müller, R.; Riedel, M.; Vette, M.; Corves, B.; Esser, M.; Hüsing, M.: Reconfigurable Self-optimising Handling System. In: S. Ratchev and M. Hauschild (eds.): Precision Assembly Technologies and Systems. 5th International Pre-cision Assembly Seminar IPAS 2010. IFIP AICT 315. Chamonix, France 14.-17. Februar 2010. Springer, Berlin 2010. ISBN: 978-3-642-11597-4. S. 255-262
 Riedel, M.; Nefzi, M.; Corves, B.: Grasp Planning for a Reconfigurable Parallel Robot with an Underactuated Arm Structure. In: Mechanical Science., 1, 33-42, doi:10.5194/ms-1-33-2010, 2010
 Riedel, M.; Nefzi, M.; Corves, B.: Performance Analysis and Dimensional Synthesis of a Six DOF Reconfigurable Parallel Manipulator. In: Proceedings of the IF-ToMM Symposium on Mechanism Design for Robotics. Mexico City, Mexico, September 28-30, 2010.