Flexible component handling based on the reconfigurable parallel kinematic structure PARAGRIP

In recent years, the framework conditions for manufacturing companies have changed fundamentally in the direction of increasing complexity and dynamics within companies and in the industrial environment. In addition to ongoing globalisation, the factors responsible for this are rapid technological development and a changing resource situation, which requires a rethinking of automation technology. A stronger focus on individualized production through flexibility and adaptability of packaging, assembly and handling systems helps to resolve the dilemma between economic productivity and differentiating variants.

A new handling system was developed at the IGMR as a cost-effective solution for adapting to part-dependent tasks. Due to a changeable and modular design, the kinematic structure can be adapted quickly and easily to the respective motion task. The handling concept is based on the manipulation of objects via several mobile robot arms, which have a parallel kinematic structure. The object is integrated into this newly constructed structure every time it is gripped and can be moved freely, comparable to the platform of a parallel manipulator in space with the degree of freedom F=6.

This concept, the resolution of the classical boundaries between robot and gripper creates the flexibility that is necessary to be able to handle very different and large-area components. Adaptation to a change in component geometry or movement is done automatically by selecting the contact points at which the connection between the arms and the object is established. In addition, the individual arms can also be rearranged based on the specifications of a configuration planning tool. The combination of contact points and arm base points has a decisive influence on the characteristics of the movement, such as the working area, accuracy and stiffness, as well as the force and speed transmissions to the drives.

The configuration of the compound can also be adapted and changed actively during object manipulation, if the object is transferred to additional arms in the sense of "grabbing". A graphical user interface with algorithms for self-optimization of the system supports the user in planning the configuration and movement. In contrast to cooperating robots, the individual robot arms have been specially developed and designed for the reconfigurable compound, which allows a simplified and economical drive concept as well as a mobile and easy assembly of the kinematic units. The handling concept, which was developed throughout the phases of conception, structural synthesis, kinematic dimensional synthesis, design and construction, was developed at IGMR and implemented in a prototype with the friendly support of Stöber Antriebstechnik.

Current prototype at IGMR: Object handling with three or four arms

The handling concept is currently being further developed and tested in a second demonstrator as part of the ICD D-3.2 "Reconfigurable self-optimizing component handling" excellence cluster project in cooperation with the WZL-MT.

Acknowledgement

The Institute of Mechanism Theory, Machine Dynamics and Robotics cordially thanks Stöber Antriebstechnik, Pforzheim as well as the DFG for their suppport in the realization of this handling concept.

Selected Literature:

[1] Nefzi, M; Riedel, M.; Corves, B.: Entwicklung und Konstruktion eines Mehrfingergreifers für die geschickte Manipulation. In: Mechatronik 2006, 4. IFAC-Symposium Mechatronische Systeme. 14. September 2006, Heidelberg.

[2] Riedel, M.; Nefzi, M.; Hüsing, M.; Corves, B.: Ein verstellbarer Greifer als rekonfigurierbarer Roboter mit paralleler Struktur. Zweiter Internationaler Workshop über Grundsatzfragen und zukünftige Forschungsrichtungen für Parallelmechanismen und Manipulatoren, 21.-22. September 2008, Montpellier, Frankreich.

[3] Müller, R.; Corves, B.; Hüsing, M.; Esser, M.; Riedel, M.; Vette, M.: Rekonfigurierbares selbstoptimierendes Bauteilhandling. Eingang: 8. Kolloquium Getriebetechnik Aachen 2009. Verlagshaus Mainz, Aachen, 2009. ISBN: 3-86130-984-X. S. 297-311.

[4] Müller, R.; Riedel, M.; Vette, M.; Corves, B.; Esser, M.; Hüsing, M.: Rekonfigurierbares, selbstoptimierendes Handlingsystem. In: S. Ratchev und M. Hauschild (Hrsg.): Precision Assembly Technologies and Systems. 5. Internationales Seminar für die Präzisions-Vollversammlung IPAS 2010. IFIP AICT 315. Chamonix, Frankreich 14.-17. Februar 2010. Springer, Berlin 2010. ISBN: 978-3-642-1159797-4. S. 255-262

[5] Riedel, M.; Nefzi, M.; Corves, B.: Greifplanung für einen rekonfigurierbaren Parallelroboter mit unterbetätigter Armstruktur. In: Mechanische Wissenschaften, 1, 33-42, doi:10.5194/ms-1-33-2010, 2010

[6] Riedel, M.; Nefzi, M.; Corves, B.: Performance Analysis and Dimensional Synthesis of a Six DOF Reconfigurable Parallel Manipulator. In: Tagungsband des IF-ToMM Symposiums zum Thema Mechanism Design for Robotics. Mexiko-Stadt, Mexiko, 28.-30. September 2010.