Arcs and weld seams in a virtual world

Potential savings in welder training

The helmet, torch and work piece may be models, but at least they are real objects. Add a PC and a screen to these components and you have a virtual welder training tool. Even the arc and the weld seam, created with all the right sound effects, are virtual creations. Virtual welding cuts down drastically on the material-intensive sessions needed when training welders on "real" welding equipment, resulting in considerable savings in time, space, materials, gas, filler material and energy. Visitors to "Schweissen & Schnei-den" will be treated to the first outing of the Fronius prototypes in both port-able case and terminal formats.

The cost of manual skills
It takes a lot of talent and hard work to develop from a beginner to a skilled worker. Precise manual skills, and a finely honed ability to identify the right sound, are developed over countless hours of practice. Whether learning to play the violin or weld seams with a welding torch, the process is exactly the same, albeit with a couple of key differences. The trainee welder will consume considerable quantities of shielding gas, welding wire, metal plate and power, not to mention that a welding "finger exercise" involves working with an arc whose temperature exceeds 2000°C. In contrast to young musicians, young welders certainly cannot practice the tools of their trade unsupervised. "Virtual welding" is the alternative, eliminating the downside associ-ated with the costs, emissions and safety aspects of embarking on a career in welding. The virtual nature of the project is attractive for youngsters brought up in the digital age, as well as boosting the image of welding as an occupation.

Virtual training world
"Virtual welding" creates a safe environment for trainees to hone their abili-ties in the fundamental welding skills of hand movements and the ability to tune in to the sound made by the process. A magnetic tracking system de-tects even the slightest hand movements and transmits these to the virtual world, represented on a touchscreen or 3D glasses. A magnetic transducer underneath the work piece generates a spherical magnetic field and a sen-sor detects the position of the welding torch. The digitised signal containing the position data forms the input for the visualisation software, which evalu-ates the positions of the torch and work piece. An additional sensor on the welding helmet provides a "real" view of the welding task, be it close up, from a distance or from different angles.
The effect of gravity on the viscous weld metal and its solidification can be seen in remarkable detail as the position of the torch relative to the work piece changes. The typical weld seam characteristics resulting from the in-fluence of different welding parameters are faithfully reproduced. In addition to the visual stimuli, the welder hears the typical welding noises accurately and in real time.

Structured learning
As the trainees guide their torches along the sample work pieces, they men-tally process the visual and audible analogue signals to determine whether the welding speed, torch distance and angle are all correct. They respond with the hand and "store" what they've learned in their brain's motor function memory.
The didactic virtual welding concept consists of training sessions and simu-lation sessions. In the training sessions, trainees first practice speed control by guiding the torch until they have accumulated the required number of points. Next, the trainees also practice achieving the optimum distance and the correct angle between torch and work piece. 
Virtual welding simulates different process conditions with instructive exam-ples, which include setting the parameters. Progress in terms of the confi-dent and safe handling of the torch is individually documented and evalu-ated.

The "training workshop" comes in the form of either a terminal, e.g. for col-leges and training centres, or a mobile case that be can be taken to the training location. A structured database, similar to a server, can be used by the instructor to create, save and recall application-specific or trainee-specific teaching environments. As a result, creative teaching sessions pit-ched at the appropriate level can be put together to teach the skills needed at the various stages of the learning process. The work surface height is fully adjustable to accommodate all shapes and sizes. The trainer uses a scoring system to provide an objective assessment of the skills on display.

An online team
A major benefit of learning with the virtual welding training tool is its net-work, and hence teamwork, capability. Ideas emerging from the dynamics of the group boost performance and support the progress of every trainee. Online teams consisting of trainees from around the world also help to bo-ost every individual's non-welding abilities, e.g. by improving language skills. The trainer can organise web-based comparisons without having to worry about language barriers, and illustrate in a light-hearted way the competitive nature of the international world of work.
The network capability of virtual welding has the added bonus of a fast and reliable online service facility.
The user can download any necessary updates, or order them to be deliv-ered on DVD. The system is able to accept upgrades, e.g. new processes or hardware.
The virtual training tool is neither sector- nor company-specific.

Summary: benefits and perspectives
A conventional training course usually involves 2 sessions of 60 hours of practical training before trainee welders can successfully complete the course and receive their certificates. Obtaining this coveted qualification, which confirms that the trainee is capable of producing useable welding re-sults, normally consumes a significant amount of material resources, such as steel, aluminium or copper plate, shielding gas, welding current and filler metal. Virtual welding reduces consumption of these valuable resources by up to 25%. It likewise shortens the training time required by a quarter. And this doesn't take into account the difficult-to-quantify consequences of phy-sical and emotional stress following accidents, damage to clothing and e-quipment or simply the frustration of making mistakes.
Alongside the undisputed fun factor that virtual welding brings to learning, it also has some more serious benefits: training costs are lowered and the environment and the climate are protected.