This paper presents the design and validation of a novel and universal 6D seam tracking system that reduces the need of accurate robot trajectory programming and geometrical databases in robotic arc welding. Such sensor driven motion control together with adaptive control of the welding process is the foundation for increased flexibility and autonomous behavior of robotic and manufacturing syst...

Abstract: Many physical systems such as welding processes are typically non-linear and uncertain. To control such systems effectively the control scheme requires to be robust with respect to varying operating conditions. On the basis of robust control Lyapunov function method and adaptive non-linear damping approach, this paper presents a robust adaptive control scheme for uncertain non-linear ...

The accuracy requirements of laser welding put high demands on the manipulator that is used. To use industrial six-axis robots for manipulating the laser welding optics, sensors measuring the seam trajectory close to the focal spot are required to meet the accuracy demands. When the measurements are taken while the robot is moving, it is essential that they are synchronized with the robot motio...

Gas tungsten arc welding is the primary process for precision joining. To develop a control system for this process, a novel sensor is proposed to measure the depth of the weld pool surface using a non-transferred arc. A flat surface is periodically established to provide a real-time reference. The main-arc-on period is selected as the system’s input. Because of possible large variations/ranges...

This study addresses intelligent techniques for fulfilling quality control of bead-on-plate welding. A new visual double-sided sensing system capable of imaging the weld pool topside and backside simultaneously in a frame was provided to determine the weld pool geometry parameters. The imaging principle was analyzed with spectrum distribution, in which the weld pool was illuminated by arc light...

background: one of the methods used for joining metals together is welding, which can be carried out using different techniques such as electric spot welding. this study evaluated the effect of electric spot welding on the load defl ection rate of stainless steel and chromium-cobalt orthodontic wires. materials and methods: in this experimental-laboratory study, load defl ection rate of 0.016 ×...

This work presents the procedure qualification for pipeline orbital welding using a robotic system. The system has four degrees of freedom, which allow the controlling of the stick out, the travel speed, the torch angle and the positioning. The arc voltage and welding current are also controlled during the welding, although the system uses a conventional power source. With the system it is poss...

Titanium alloys have found increased applications in various industrial sectors. One of the critical issues in quality control is the weld penetration during welding. In the present paper, tungsten inert gas (TIG) welding of Ti-6Al-4V alloy with and without an activating flux was conducted. The effect of the activating flux on Ti alloy welding was investigated. A data acquisition system was use...

Recently, the incidence of pneumoconiosis due to inhalation of welding fumes has become increasingly remarkable in Japan. Although several engineering methods such as local exhaust ventilation, push-pull ventilation and general (dilution) ventilation have been preferred for controlling airborne contaminants released from welding work, thorough reduction of the welder’s exposure to welding fumes...

This paper addresses the development of an adaptive control system for keyhole arc welding process. The system developed adjusts the amperage of the peak current to achieve the desired peak current period under varying manufacturing conditions. A nominal model is selected from models identified using experimental data and is used as the a prior model of the controlled process. A predictive cont...