Laser Scanning with Industrial Robot Arm for Raw-wood Fabrication

This paper presents an integrated raw-wood fabrication workflow using an industrial robot arm and a laser scanner. The research is situated in a Swiss mountain forestry context where timber in its natural form could be applied locally without relying on large centralized timber industries. While local saw-mills relies on the standard processing tools to transform raw-wood into regular beams and boards, an automated robotic application could exploit timber in its natural form directly for construction. The research proposes a digital fabrication workflow that links industrial robot arm and laser scanning to adapt timber joinery tool-paths to irregular raw-wood such as straight, bent and forked tree trunks. The application employs ABB IRB6400 robot and Faro Focus S150 laser scanner. Several methods are developed for the point-cloud processing including flat-cut sectioning, mesh reconstruction and cylinder fitting. The methodology is tested in two stages: a) scanning a set of tree trunks b) continuous integration within robotic fabrication. The findings compare the scanning method in regards to calibration, pointcloud processing, time needed to communicate between the robot controller, the accuracy of the application. The results show that is possible to perform robotic cutting and scanning interchangeably and the speed of the scanning application is proportionally fast (3-4 min) considering the overall robotic cutting time (60-90 min) depending on the study case.