Laser welding of dissimilar aluminium alloys with filler material Luís Filipe Amaro Pinto Instituto Superior Técnico – Technical University of Lisbon – Portugal September 2008 Abstract The aluminium alloys are materials with great potential because of its high strength and low weight. However, the welding of dissimilar aluminium alloys is difficult in autogeneous welding, due to these alloys ar...

Today, welding tasks can be accomplished in two ways: 1) Manual or conventional, which is made by humans with a welding gun; and 2) Automated welding that is carried out by robots, this robots are called “Welding Robots”. Current welding robots are able to perform welding tasks continuously under different working conditions in low-scale production such as shipbuilding or in high-scale producti...

This paper aims at the development of an advanced control technology for pulsed gas metal arc welding (GMAW) of titanium or other materials which require a highly stable metal transfer process. It is known that conventional pulsed GMAW achieves stable and repeatable spray transfer by using correct pulse parameters. Because the optimal pulse parameters depend on welding parameters such as wire f...

This paper describes the development of a selfdriving mobile welding robot. The robot is used to weld U-shaped welding areas in enclosed double-hull structures. In order to place itself inside the double-hull structure, the robot is capable of passing through an access hole 600 mm wide and 800 mm high. This research addresses the mechanical and control systems of the robot. The mechanical syste...

To address control difficulties in laser welding, we propose the idea of a self-learning and self-improving laser welding system that combines three modern machine learning techniques. We first show the ability of a deep neural network to extract meaningful, low-dimensional features from high-dimensional laser-welding camera data. These features are then used by a temporal-difference learning a...

This Thesis describes novel image template based methods for robust and real-time capable tracking and visual quality inspection tasks in harsh environments. The presented tracking methods include three different constitutive approaches. First, a spline-regularized template tracking method applied for weld seam tracking in industrial robotic welding environments is presented. Second, a template...

in this paper, thermal effect of plasma arc welding is investigated, and temperature field of ferrite stainless steel is acquired. thermal effect of plasma arc and subsequently the generated temperature field in the work piece is the key for analysis and optimization of this welding process, which is the main goal of this paper. finite element simulation of welding process by simplec method and...

In robotic welding seam tracking based on visual information has been studied in the recent years. However, it is difficult to ensure the quality of images obtained in the welding process because it is easily affected by spattering, fuming and electromagnetic noise. The paper introduces a method to select useful images before further processing. Experimental tests are conducted to verify its ac...

BACKGROUND Occupational exposure is estimated to contribute 15% to the burden of chronic obstructive pulmonary disease (COPD). Welding fumes are suspected to accelerate the decline of lung function and development of COPD. AIMS To examine the relationship between welding fume exposure and COPD in Korean shipyard welders. METHODS The study involved a group of male welders working at two ship...