Robotic arc welding sensors and programming in industrial applications

P Kah,M Shrestha,E Hiltunen,J Martikainen

doi:10.1186/s40712-015-0042-y

Abstract

Technical innovations in robotic welding and greater availability of sensor-based control features have enabled manual welding processes in harsh work environments with excessive heat and fumes to be replaced with robotic welding. The use of industrial robots or mechanized equipment for high-volume productivity has become increasingly common, with robotized gas metal arc welding (GMAW) generally being used. More widespread use of robotic welding has necessitated greater capability to control welding parameters and robotic motion and improved fault detection and fault correction. Semi-autonomous robotic welding (i.e., highly automated systems requiring only minor operator intervention) faces a number of problems, the most common of which are the need to compensate for inaccuracies in fixtures for the workpiece, variations in workpiece dimensions, imperfect edge preparation, and in-process thermal distortions. Major challenges are joint edge detection, joint seam tracking, weld penetration control, and measurement of the width or profile of a joint. Such problems can be most effectively solved with the use of sensory feedback signals from the weld joint. Thus, sensors play an important role in robotic arc welding systems with adaptive and intelligent control system features that can track the joint, monitor in-process quality of the weld, and account for variation in joint location and geometry. This work describes various aspects of robotic welding, programming of robotic welding systems, and problems associated with the technique. It further discusses commercially available seam-tracking and seam-finding sensors and presents a practical case application of sensors for semi-autonomous robotic welding. This study increases familiarity with robotic welding and the role of sensors in robotic welding and their associated problems.

Highlights

Industrial robots and mechanized equipment have become indispensable for industrial welding for high-volume productivity because manual welding yields low production rates due to the harsh work environment and extreme physical demands (Laiping et al 2005)
Especially in the auto industry, involve producing a series of short and repeated welds for which real-time tracking is not required; it is necessary to begin each weld in the correct place, which necessitates the use of seam-finding sensors (Meta Vision Systems Ltd 2006)
Experiments show that the technique is appropriate to scan a variety of surfaces and, in particular, the intended metallic parts for robotic welding tasks (Rodrigues et al 2013b)

Summary

Introduction

Industrial robots and mechanized equipment have become indispensable for industrial welding for high-volume productivity because manual welding yields low production rates due to the harsh work environment and extreme physical demands (Laiping et al 2005). The main use of sensors in robotic welding is to detect and measure process features and parameters, such as joint geometry, weld pool geometry and location, and online control of the welding process.

Results

Conclusion