Mobile Laser Trackers for aircraft manufacturing:
Increasing accuracy and productivity of robotic applications for large parts 2019-01-1368
The demand for higher production rates of large parts in aircraft industry requests more flexible manufacturing solutions. High-accurate mobile robots show a promising alternative in comparison with high-invest special machines. With mobile robot-based solutions processes can be executed simultaneously which increases the productivity significantly. However, the freedom of mobility results in insufficient positioning accuracy of these machines. Hence, fast and accurate referencing processes are required to achieve cost-effectiveness and meet production tolerances.
Laser Trackers show an increasing maximum permissible error with increasing distance of the measurement target. For vast machines and components the achievable reference accuracy can be insufficient, due to high measurement distances. Visibility of measurement targets, especially for mobile machines, has a further limiting impact on finding suitable measurement positions. Therefore, often multiple systems are required at one station. By repositioning the measurement system visibility and accuracy can be optimized. As a manual process, this would cause higher effort and auxiliary process time. With mobile Laser Trackers the area of operation can be expanded while at the same time increasing the return on invest.
In this publication a mobile Laser Tracker system will be introduced. The realized system consists of an automated guided vehicle (AGV) and a Laser Tracker mounted on the AGV. Due to the mobility and the resulting time-variant transformations, initial position values are required at each location of the system. Therefore, a precise relationship between the mapping of the environment and the coordinate system of the laser tracker must be determined. The approach shown increases the measurement accuracy and visibility of targets. In addition, economic benefits resulting from sharing the system in multiple manufacturing stations are discussed. Finally, a holistic approach for controlling and optimizing referencing processes introduced here will provide a foundation for future mobile manufacturing systems.
Christoph Brillinger, Hendrik Susemihl, Fabian Ehmke, Till Staude, Kevin Deutmarg, Maximilian Klemstein, Christian Boehlmann, Wolfgang Hintze, Jörg Wollnack
Fraunhofer IFAM, MABI Robotic, FFT Produktionssysteme GmbH & Co KG, Hamburg University of Technology