Off-line path programming for three-dimensional robotic friction stir welding based on Bézier curves
ISSN: 0143-991X
Article publication date: 9 November 2018
Issue publication date: 7 December 2018
Abstract
Purpose
Robotic friction stir welding (RFSW) is an innovative process which enables solid-state welding of aluminum parts using robots. A major drawback of this process is that the robot joints undergo elastic deformation during the welding, because of the high forces induced by the process. This leads to tool deviation and incorrect orientation. There is currently no computer-aided manufacturing/computer-aided design (CAD) software for generating off-line paths which integrates robot deflections, and the main purpose of this study is to propose an off-line methodology to plan a path for RFSW with the integration of the deflections.
Design/methodology/approach
The approach is divided into two steps. The first step consists of extracting position and orientation data from CAD models of the workpieces and adding the deflections calculated with a deflection model to generate a suitable path for performing RFSW. The second step consists of the smooth fitting of the suitable path using Bézier curves.
Findings
The method is experimentally validated by welding a curved workpiece using a Kuka KR500-2MT robot. A suitable tool position and orientation were calculated to perform this welding, an experimental procedure was set up, a defect-free weld was performed and a high accuracy was achieved in terms of position and orientation.
Practical implications
This method can help manufacturers to easily perform RFSW for three-dimensional workpieces regardless of the lateral tool deviation, loss of the right orientation and control force stability.
Originality/value
The originality of this method lies in compensating for robot deflections without using expensive sensors, which is the most commonly used method for compensating for robot deflection. This off-line method can lead to a reduction in programming time in comparison with teach programming method and leads to reduced investment costs in comparison with commercial off-line programming packages.
Keywords
Acknowledgements
This work is a part of NOUGAT project. The authors wish to thank the CORAC for the financial support and Stelia Aerospace for providing the clamping device for the validation experiments.
Citation
Kolegain, K., Leonard, F., Chevret, S., Ben Attar, A. and Abba, G. (2019), "Off-line path programming for three-dimensional robotic friction stir welding based on Bézier curves", Industrial Robot, Vol. 45 No. 5, pp. 669-678. https://doi.org/10.1108/IR-03-2018-0038
Publisher
:Emerald Publishing Limited
Copyright © 2018, Emerald Publishing Limited