• Dobie, Gordon
• Loukas, Charalampos
• Gachagan, Anthony
• Sibson, Jim
• Jones, Richard
• Macleod, Charles N.
• Warner, Veronica
• Pierce, Stephen

Abstract

There is a need for automated intelligent welding systems in multiple industrial manufacturing and repair scenarios, especially for Small to Medium Enterprises (SMEs) where production flexibility is required. Although welding robots are an important enabler for intelligent welding systems, traditional manual teaching of robot paths and allocation of welding parameters for multi-pass robotic welding is still a cumbersome and time-consuming task, which decreases the flexibility, adaptability, and the potential of such systems. <br/>The developments of a compact, autonomous, and flexible robotic welding system are presented herein, consisting of a small (500 mm reach) 6-DoF robot with a flexible mounting arrangement for varying weld applications deployment. Optical and tactile sensing are utilized to identify and extract the feature characteristics of single-sided V-groove geometries while robotic motion is purely sensor-driven in real-time allowing the generation and adaption of the welding paths to varying V-groove geometries and random poses of the joint configuration. <br/>To fulfil the need for automated robotic welding, a new adaptive fill sequencing framework is presented, enabling automatic planning of multi-pass welding for single-sided V-groove geometries. Driven with commercial aspects in mind, a novel cost-function concept has been permutated and identifies the optimum welding parameters for each layer through a user-driven weighting, delivering the minimum number of passes, filler material and welding arc time based on application requirements. <br/>The concept methodology and framework were verified experimentally, through automated robotically deployed Gas Metal Arc Welding (GMAW) developed system. For a given representative joint, the arc welding time and filler wire requirement were found to be 32.9% and 26.2% lower respectively, than the worst-case available welding parameter combination, delivering a corresponding decrease in direct manufacturing costs. An ultrasonic inspection was also undertaken to verify the consistent quality of the weldments and validate the framework outcomes for enabling future successful exploitation. <br/>

Topics

• impedance spectroscopy
• positron annihilation lifetime spectroscopy
• Photoacoustic spectroscopy
• ultrasonic
• random
• wire