Development and Validation of Algorithms Employed for Sensor Systems in Robotic Orbital Root Pass Welding of Pipelines‏

Abstract

The commercial welding systems for orbital welding automation face challenges regarding the robot path control and the process parameters. Pipes from oil and gas companies present discontinuities caused by the manufacturing stage that are critical for the welding process. To overcome this, the present paper investigates the use of sensors for real time correction in orbital welding. An anthropomorphous robot guides the torch. A through-arc sensor for seam tracking and an electrical contact sensor for seam finding were employed. A program for automatic path planning and welding parameters allocation was developed. The proposed strategy and the arc sensor torch control were validated based on weld deposits on pipe. The root pass welding was next performed using a short-circuit control GMAW process with the arc sensor.

Key-words:
Orbital welding; Robotic welding; Through-arc sensor; GMAW CCC