Study on Workpiece and Welding Torch Height Control for Polydirectional WAAM by Means of Image Processing

Reisgen, Uwe; Mann, Samuel Micha; Oster, Lukas; Lozano, Philipp; Sharma, Rahul

doi:10.1109/coase.2019.8843076

Cited by 12 publications

(6 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This approach was already used by Reisgen et al [33] for measuring the workpiece height with subsequent height control. The actual measured robot path was superimposed on a grid to store the measured part heights.…”

Section: Infill Strategiesmentioning

confidence: 99%

“…By comparing the coverage analysis presented here with the measured coverage or part height of a real object, weld seam modeling can be improved. Furthermore, a predictive control is conceivable, which does not react to a varying workpiece geometry in the next layer, as described by Reisgen et al [33]. With this predictive control, the workpiece height could ultimately be ensured in the first layer through dynamic process parameter adaption.…”

Section: Infill Strategiesmentioning

confidence: 99%

See 1 more Smart Citation

A Robot-Centered Path-Planning Algorithm for Multidirectional Additive Manufacturing for WAAM Processes and Pure Object Manipulation

et al. 2021

View full text Add to dashboard Cite

Previous algorithms for slicing, path planning or trajectory planning of additive manufacturing cannot be used consistently for multidirectional additive manufacturing with pure object manipulation in wire-arc additive manufacturing. This work presents a novel path planning approach that directly takes robot kinematics into account and thus ensures the reachability of all critical path poses. In an additional step, the planned path segments are smoothed so that joint velocity limits are respected. It is shown that the implemented path planner generates executable robot paths and at the same time maintains the process quality (in this case, sufficient coverage of the slice area). While the introduced method enables the generation of reachable printing paths, the smoothing algorithm allows for the execution of the path with respect to the robot’s velocity limits and at the same time improves the slice coverage. Future experiments will show the realization of the real robot setup presented.

show abstract

Section: Infill Strategiesmentioning

confidence: 99%

Section: Infill Strategiesmentioning

confidence: 99%

A Robot-Centered Path-Planning Algorithm for Multidirectional Additive Manufacturing for WAAM Processes and Pure Object Manipulation

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Tool-path algorithms were not only developed and optimized in one plane (x,y) but also researched and optimized in the vertical plane (z-axis). One example of Reisgen et al [15] can be stated here for the study on workpiece and welding torch height control in polydirectional WAAM applications that was applied to different materials. In this research, the current wire stickout length was acquired by means of image processing and combined with the actual position of the welding torch to compute a workpiece elevation map.…”

Section: Related Workmentioning

confidence: 99%

Development of a Multidirectional Wire Arc Additive Manufacturing (WAAM) Process with Pure Object Manipulation: Process Introduction and First Prototypes

Parmar

Oster

Mann

et al. 2021

JMMP

View full text Add to dashboard Cite

Wire Arc Additive Manufacturing (WAAM) with eccentric wire feed requires defined operating conditions due to the possibility of varying shapes of the deposited and solidified material depending on the welding torch orientation. In consequence, the produced component can contain significant errors because single bead geometrical errors are cumulatively added to the next layer during a building process. In order to minimise such inaccuracies caused by torch manipulation, this article illustrates the concept and testing of object-manipulated WAAM by incorporating robotic and welding technologies. As the first step towards this target, robotic hardware and software interfaces were developed to control the robot. Alongside, a fixture for holding the substrate plate was designed and fabricated. After establishing the robotic setup, in order to complete the whole WAAM process setup, a Gas Metal Arc Welding (GMAW) process was built and integrated into the system. Later, an experimental plan was prepared to perform single and multilayer welding experiments as well as for different trajectories. According to this plan, several welding experiments were performed to decide the parametric working range for the further WAAM experiments. In the end, the results of the first multilayer depositions over intricate trajectories are shown. Further performance and quality optimization strategies are also discussed at the end of this article.

show abstract

“…Reisgen et al create a layer-wise elevation map of the previous deposited layer using optical image processing [15]. This is then used for implementing two control loops of the layer height.…”

Section: Introductionmentioning

confidence: 99%

“…One controls the distance between the torch and the work piece, and the second controls the wire feed speed. The system reduces the deviation of the actual height to the target height from 25% in the uncontrolled case to 7% for the controlled system [15].…”

Section: Introductionmentioning

confidence: 99%

Detection of the contact tube to working distance in wire and arc additive manufacturing

Hölscher

Hassel

Maier

2022

Int J Adv Manuf Technol

View full text Add to dashboard Cite

Currently, wire and arc additive manufacturing (WAAM) is mainly done by planning the torch movements layer wise. The height step between the layers is derived from preliminary experiments. Small deviation in the determination of the height step can accumulate over the layers and lead to improper shielding gas conditions or a collision the between torch and the work piece. This makes continuous process monitoring necessary. To overcome these problems, a closed-loop layer height control strategy is beneficial. For the development of a closed-loop height control strategy, it is necessary to have knowledge of the effective height step between the layers during manufacturing. The present study focuses on the development of a sensing method, which allows users to detect the contact tube to working distance (CTWD) in WAAM. The system was developed for short circuit mode of gas-metal arc welding WAAM. The system can also provide information on whether the torch passes over weld beads crossing the weld track or other geometric irregularities existing in the z-direction. Several characteristic values of the process were detected and were matched to the actual CTWD. The accuracy of the sensing method was evaluated, and based on the measured correlation and standard deviation, the electrical resistance during short circuit monitored the CTWD best.

show abstract

Study on Workpiece and Welding Torch Height Control for Polydirectional WAAM by Means of Image Processing

Cited by 12 publications

References 7 publications

A Robot-Centered Path-Planning Algorithm for Multidirectional Additive Manufacturing for WAAM Processes and Pure Object Manipulation

A Robot-Centered Path-Planning Algorithm for Multidirectional Additive Manufacturing for WAAM Processes and Pure Object Manipulation

Development of a Multidirectional Wire Arc Additive Manufacturing (WAAM) Process with Pure Object Manipulation: Process Introduction and First Prototypes

Detection of the contact tube to working distance in wire and arc additive manufacturing

Contact Info

Product

Resources

About