Automation of welding process in shipyard is ultimately necessary, since welding site is spatially enclosed by floors and girders, and therefore welding operators are exposed to hostile working conditions. To solve this problem, a welding robot that can navigate autonomously within the enclosure needs to be developed. To achieve the welding task, the robotic welding system needs a sensor system...

This study aims to calculate the resistance spot welding current digitally at a fast speed. The conventional open-loop spot welding machine cannot measure the current, thus the welding quality varies. The welding time of spot welder is very short, but the welding current is strong and it is hard to be measured, thereby resulting in the uncontrollability of welding quality. This study uses a hig...

Rapid prototyping (RP) methods are used for production easily and quickly of a scale model of a physical part or assembly. Gas metal arc welding (GMAW) is a widespread process used for rapid prototyping of metallic parts. In this process, in order to obtain a desired welding geometry, it is very important to predict the weld bead geometry based on the input process parameters, which are voltage...

Most previous welding simulations are based on a flat weld pool surface and become unmeaningful when the surface deformation is significant. In recent years, some researchers have developed numerical models capable of simulating free surface motion in welding processes, but they focus on the discussions of physical equations, boundary conditions, and solutions, rather than the numerical algorit...

Welding processes are one of the most widely spread industrial activities, and their quality control is an important area of research. The presence of residual traces from the protective antioxidant coating, is a problematic issue since it causes a significant reduction in the welding seam strength. In this work, a solution based on a Laser Induced Breakdown Spectroscopy (LIBS) setup and a Supp...

MAY 2003 -S 116 ABSTRACT. Mechanical characteristics of resistance spot welding machines, such as stiffness, friction, and moving mass, have complex influences on the resistance welding process and weld quality. In this paper, these influences are systematically investigated through experiments. The mechanisms of the influences are explored by analyzing process signatures, such as welding force...

Although robotic machines are routinely used for welding, such machines do not normally incorporate intelligent capabilities. We are studying the general problem of formulating usable levels of intelligence into welding machines. From our perspective, an intelligent machine should: incorporate knowledge of the welding process, know if the process is operating correctly, know if the weld it is m...

Automation of welding process in shipyard is ultimately necessary, since welding site is spatially enclosed by jloors and girders, and therefore welding operators are exposed to hostile working conditions. To solve this problem, recently a robotic welding system f o r closed block assembly has been developed. For complete autonomy, this system needs a sensor system for the weld seam tracking an...

Simplified fatigue and fracture mechanics based assessment methods are widely used by the industry to determine the structural integrity significance of postulated cracks, manufacturing flaws, service-induced cracking or suspected degradation of engineering components under normal and abnormal service loads. In many cases, welded joints are the regions most likely to contain original fabricatio...

This thesis deals with the problem of seam detection for robotic laser welding applications. Within the Mechanical Automation laboratory of the Engineering Technology faculty, a compact, lightweight and multi-purpose welding head is developed. The integrated welding head is attached to a robot and should be able to detect seams, learn trajectories, do the laser welding and inspect the welds. A ...