Robot Used for Complicated Cuts

Usually you hear about robots used for jobs that are dangerous, repetitive or just plain drudgery. In this case, a job for cutting a hole through the wall of a pressure vessel, the robot was called upon because it can be smarter than a person.

The pressure vessel was a 49 and a half foot (15 meter) diamenter hemi-sphere with 2 7/8 inch (7.3 cm) thick walls. They needed to cut holes for 16 inch (40 cm) pipes to enter the tank on the curved surfaces.
What are the shapes of the holes that need to be cut?

In the past, they might have built special fixtures, one for each hole, to guide the cutting torch.
But Arc Specialties used a modified ABB welding robot and RobotStudio simulation software to create a hole-cutting expert. They programmed a macro into the control software so that the operator only needed to know the size of the the hole and the location on the tank and the robot would calculate the cutting details.

The robot was placed on a scaffolding near the holes just as any welder.


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