Kinematic measurement of a robotic arm
As new manufacturing methods develop, industrial robots are playing an increasingly important role. They are the ones who can implement the complex designs created by people. This is demonstrated by use of an independent measurement method where the design is input into the robot controller data. The robot then moves precisely and accurately to the predetermined spatial positions.
This system operates in cooperation with the wbk, Institute of Production Technology project, and deals with various fields of surveying examination. Moreover, the subsequent optimisation of innovative robot-based methods trajectory production is based on "rounds during extrusion". In this manufacturing method, it is not only necessary that the actual path of the guide tool coincides geometrically with the planned path, but it is also necessary that it is used in the right time at the right place. This requires synchronisation of manufacturing robots and laser trackers in the microsecond range.
One manufacturing robot is the 6-axis industrial robot KR 210-2 from the company KUKA. The hand of the robot is equipped from the Institute for Production Technology with a guiding tool for the feature and a "flying saw". The management tool can move over one axis, and thus form the pressed component.
Spatiotemporal measurement guide tool’s track must be studied in order to optimise the robot controller. The coordinate precision is intended to be better than 1/10 mm.
Status of Work
Currently, the focus of topographic work is the verification and optimisation of the guide tool’s track, operated without load and without the thermal influence of the extrusion press. The measurement is performed with the Laser Tracker LTD 500 and AT901 from Leica, where the kinematic performance has been tested. A synchronisation of the laser printer using production robots has been established in the microsecond range. The analysis of the 100 test runs has shown a very high reproducibility of the robot motion, it has brought insights into the starting behaviour of the robot, and it has led to the first optimisation of the robot controller.
Future plans to further the project’s preliminary steps will include impacts on the weight, the voltage and the temperature of the guide tool. The material of the guide tool’s track must also be considered as well as the effect and measured behaviour of the very complex, emerging laser tracker from the extruder temperature field.
Videos of the Survey Work
The following videos show some of the robot’s test runs. In addition, a robotic arm developed at the GIK-tracking reflector is presented. This makes it possible to follow even more pivoting movements of the guide tool than is possible with a Cateye reflector.
Short film about Robotic Surveying
Publications on the subject
Herrmann, C.; Hennes, M. (2010): Positioning and Synchronization of Industrial Robots. Proceedings of the 2010 International Conference on Indoor Positioning and Indoor Navigation (IPIN), Mautz, R.; Kunz, M. and Ingensand, H. (eds.), IEEE Xplore, p. 436-440.
Herrmann, Ch.; Hennes, M.; Juretzko, M.; Schneider, M.; Munzinger, Ch. (2010): Positionierung und Synchronisation von kooperierdenden Robotern. Festschrift zur Verabschiedung von Günter Schmitt. S. 129-134.
Herrmann, C.; Hennes, M.; Juretzko, M.; Munzinger, C.; Schneider, M. (2010): Positioning and Synchronzation of Industrial Robots. Proc. to International Conference on Indoor Positioning and Indoor Navigation, Sept. 15-17, 2010, ETH Zurich, CH
Juretzko, M.; Hennes, M. (2008): Monitoring of the spatiotemporal movement of an industrial robot using a laser tracker. Proc. To 1st Conf. Machine Guidance & Control, June 24-26, 2008, Zurich, CH.
Hennes, M. (2008): Measuring the motion - Synchronizing a laser tracker for high- accuracy handling tasks. Proc. to CMSC, Charlotte (NC), 22.-25.7.2008, p 23-28.
Juretzko, M.; Hennes, M.; Schneider, M.; Fleischer, J. (2008): Überwachung der raumzeitlichen Bewegung eines Fertigungsroboters mit Hilfe eines Lasertrackers. In: Allgemeine Vermessungsnachrichten (AVN), Heft 5/2008, S. 171-178.
Fleischer, J.; Hennes, M.; Munzinger, C.; Köhler, G.; Juretzko, M.; Schneider, M. (2008): Genauigkeitsuntersuchungen an einer fliegenden Abtrennvorrichtung. In: VDI-Z, Heft (5/2008), S.71-73.