Collaborative robots have come a long way during the past decade, particularly in metal manufacturing. They began as a curiosity. Some shops purchased a cobot or two just to see what they could do with them. Yes, they could perform light pick-and-place tasks, but that has limited applicability in sheet metal and plate fabrication. What about tending a press brake, or perhaps a hardware or stamping press? Maybe an ironworker?
These early applications mainly entailed pick-and-place actions: Pick up this part and place it in the fixture; place this flat blank against a magnetic backgauge on a press brake. Over time applications became more sophisticated. Cobots weren’t just placing parts but instead were manipulating them through the entire cycle. On a press, for instance, cobots didn’t just pick and place simple, single-bend parts, but now were carrying workpieces through more complex bend sequences.
At the same time, welding cobots began hitting the market, and the industry’s thinking about cobots began to shift. No longer were they a novelty for simple applications. Cobots now were tackling the arena of semiskilled work. And for fabricators, a cobot wielding a lightweight welding torch and associated wire feeds and gas lines made more sense than using a payload-limited cobot to lift and hold heavy or unwieldy pieces of sheet metal or plate.
Cobots have spurred shops to think about automation differently. Automation isn’t an all-or-nothing concept, but instead a spectrum of innovations that change how workers interact with machines and technology. And more than many manufacturing technologies, cobots have pushed shops to focus on making the most of that human-machine interaction.
A Spectrum of Automation
Failed attempts at using automation certainly aren’t unusual, a telltale sign being a dusty welding robot or two sitting in the corner. Perhaps the fab shop had trouble repurposing them after a high-volume welding job ended. Programming took too much time. A welder simply could fixture and weld the work rather than bothering with the complications of programming.
True, more precision processes upstream have made welding automation downstream more practical in many situations. But this still doesn’t account for another reality in modern fabrication: 3D CAD models aren’t as ubiquitous as many think they are. That fact makes adopting a host of automation options, including offline programming and simulation, a bit more complicated.
“We take the automation-as-a tool approach,” said Josh Pawley, vice president of business development and founding partner of Loveland, Colo.-based Vectis Automation. “There’s a real risk in overautomating. We see so much value in the person-plus-machine approach. We keep the operator in the loop and always ask, ‘Does this application really need to be fully automated?’’’
Most welding cobot applications involve tabletop welding. Programmers fixture a piece, use a simplified interface to teach the robot, then let the cobot produce. That programmer could leave workpiece fixturing and removal to a material handler or helper and move elsewhere to weld parts that aren’t a good fit for the cobot, including large workpieces.
But as Pawley noted, that’s just one approach. He described some fabricators who have welders set up a cobot and then work on another manual welding application alongside it. Alternatively, one welder/programmer can spend a shift managing a “team” of cobot welding cells.