Teaching robots to weld with the skill of a human worker is easier said than done, but ABB’s new VirtualArc software is said to allow operators to perfect the welding procedure from their desks, without tying up the robot or wasting resources through real-life trial and error.
Precise, clean, mass-produced welds are taken for granted by consumers of manufactured products, but they are not so easily achieved. Human welders draw on their experience, intuition and a trial-and-error to establish the right parameters for the job.
Transferring this kind of skill to a robot is not easy, but it is exactly what ABB has achieved with the introduction of its robot welding simulation software.
Robots have often been introduced into manufacturing plants to speed productivity and relieve workers of hazardous, strenuous or tediously repetitive tasks.
The benefits have been many-fold, from improved health and safety to lower energy bills for operators. An additional contribution comes from robots’ unerring accuracy.
Their ability to repeat tasks over and over, each time achieving the quality standards expected by customers, and ensuring that goods are finished correctly first time, with no costly repairs or wasted materials.
But robots can only get it right if they have been programmed correctly and that can be a time-consuming process. “Teaching” a robot to perform an arc-weld, for example, means providing it with the knowledge that comes from many years of human experience and the intuition that enables it to choose the appropriate process for a new task.
This in-depth understanding of the welding process can be acquired by trial and error. Indeed, most new welding parameters are established by experienced welders performing a series of test welds and adjusting parameters to hone the result, but this is a wasteful approach.
The test welds use up materials, manpower and energy. They also tie up a robot that could be in productive use elsewhere.
To reduce the need for such wasteful tests, the software provides the unique ability to define the exact weld parameters required for an application and then test them, without any welds actually being carried out.
The software uses a sophisticated simulator that incorporates information on the equipment available, such as the welding device, the power supply etc., and application data, such as the materials to be used, the plate thickness, the required joint configuration etc.
Using this information, the program can deliver a full set of weld parameters, along with a profile of the resulting weld.
This enables the operator to assess the quality of the weld produced under a particular set of conditions in the space of a few minutes, a fraction of the time needed to perform a “real” test.
Depending on the results of the virtual test, the operator can adjust parameters such as weld speed, torch angle etc. and optimise for maximum productivity and minimum energy use, while maintaining the required quality of the weld and allowing the plant’s robots to continue with their work on other applications.
As a result of pre-weld analysis, operators can save materials and energy, and reduce the production of welding fumes.