- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Development of an Intra-Layer Adaptive Toolpath Generation Control Procedure in the Laser Metal Wire Deposition Process
摘要： Recently developed concentric laser metal wire deposition (LMWD) heads allow metal addition processes which are independent of the deposition direction, thus enabling complex paths to be generated. The sensitivity of the process to height deviations has experimentally been observed to be greater with this type of head than with powder ones, therefore requiring more precise and local process control algorithms to be implemented. This work developed a methodology for measuring the part, layer by layer, using a 3D scanner based on structured laser light. Height corrections were applied to the mean and intra-layer height deviations by recalculating the deposition trajectories of the next layer to be deposited. Local height deviations were adjusted by varying the scanning speed, thus increasing the feed rate in the lower areas and decreasing it in the higher ones. Defects generated in the purpose, with height differences within the layer, were successfully corrected. A flat layer was re-established through the application of the control strategy. The internal integrity of the parts due to the scanning speed variation was analyzed, resulting in fully dense parts. The structured light measurement and height correction systems are found to be an affordable and time-efficient solution that can be integrated into an LMWD environment, thereby improving the process robustness.
关键词： cladding,coaxial wire feed,metal wire,additive manufacturing,monitoring,laser deposition,structured light scanning,height control
更新于2025-11-28 14:24:20
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Cross-lines laser aided machine vision in tube-to-tubesheet welding for welding height control
摘要： Thermal distortion was a major issue in sheet metal welding. One particular issue to be addressed in this work for tube-to-tubesheet welding was the resultant variation in the welding torch to work distance, referred to as welding height hereafter, which can easily cause undercuts and burn-through. Unfortunately, efforts on control of welding height which was particularly critical for tube-to-tubesheet welding were limited. This paper thus introduced a machine vision system with a cross-line laser as the structured light to measure the welding height for adaptive correction and control. To extract the ICCL (intersection coordinate of cross-lines laser) which provided the variation in welding height, an image processing algorithm was proposed that segmented regions and extracted their centers. A linear relationship between WHVV (welding height variation value) and ICCL was established by least square method. Performance was tested experimentally for the experiment platform and it was found that the static and dynamic detection error were insignificant, no more than 0.007 and 0.016 mm respectively. When WHVV = 1 mm, the compensation error of 115 tubes varied from ?0.037 to +0.028 mm.
关键词： Welding height control,Cross-lines laser,Machine vision,Tube-to-tubesheet welding
更新于2025-09-12 10:27:22