February 2021 Volume 3

AUTOMATION

“These days, many invest in turnkey automation systems,” said Matt Phillips, automation president for Tooling Technology Group. Some still want a machine or a workcell, but many are thinking bigger these days. “In metal fabrication, the systems often go beyond fabricating parts and perform other tasks, such as bonding,” Phillips said. Assembly and bonding aren’t necessarily difficult, but the incoming parts must conform to all the dimensional requirements for the assembly process to go as planned. Part Inspection. “In the past, part inspection was the responsibility of the machine operator,” he said. “If the machine operators were dependable, this was fine, but if not, they might load bad parts.” Getting around that problem means designing a system that does adequate inspections for the specific application. “Laser inspection equipment and camera systems are used to measure a part’s dimensions and detect part features,” Phillips said. “Often they canmeasure dimensions down to 0.0005 in. Measuring to that precision with a laser, then loading the part with a robotic system, is much faster and more reliable than an operator checking parts and loading themmanually.” *“A vision system can detect the presence of a part or a feature, so for example, it can determine whether a tube has an end form or a nut on it,” Downing said. “It also can be used to detect color, so it can determine the presence of a specific O-ring.” And vision systems can be more specific than that. “A 2D vision system can find a fitting on a tube and determine if it’s in the right location,” he said. “A 3D vision system can determine depth, so even if parts aren’t stacked in a bin in an orderly fashion, it can depict the fitting’s exact x, y, and z location.” Vision systems can be used for functions other than a preloading inspection as well. “One of our machines was used to assemble a product made from five components,” Phillips said. “Some of the components were very similar and could be fit together in the wrong order.” Preventing that was a matter of devising an error-proofing system. “The customer wanted a poka-yoke system to prevent an assembly errors—it was an automotive assembly—so we installed three cameras on the system and a profilometer to prevent assembling the unit wrong,” he said. “The poka-yoke system added 15% to the machine’s price, but the customer thought it was a worthwhile investment.” That might seem pricey in some industries, but in the automotive world, adding many thousands of dollars to the price of a machine is a good investment if it prevents a single recall. Robots and Cobots. As parts and assemblies have become more complex, the robots that assist in making them have become more sophisticated as well. These days some do more than pick parts from a bin of incoming material and move them from machine to machine for processing. Phillips described a system that performs its own diagnostics with some self-correcting capability. On occasion, a robot’s subsystems don’t quite work in unison—it tries to assemble two parts and simply fails. This can happen when

a mismatch develops among the vision system that the robot uses to sense its environment, the software that runs the robot, and the actuators that provide the robot’s motions. This sounds like a difficult problem to fix, one that requires refining the vision system software or fine-tuning the program that runs the actuators, but onboard diagnostics sometimes can remedy the situation. “A feedback loop often provides the necessary correction,” Phillips said. The feedback loop runs in the background, and the corrections take place while the system is making parts, making small corrections online. If the feedback loop can’t manage the correction while the system is running, in some cases the operator shuts the system down to try to sort it out offline. Downtime is expensive, but a self correcting system gets such problems resolved far faster than a less sophisticated system that requires a more intrusive remediation. “A less capable system just does the same motions over and over,” Phillips said. When a working environment needs both a robot and a worker, guarding is necessary to protect the worker, unless a cobot (collaborative robot) is substituted for the robot. Designed, built, and programmed specifically to share a workspace with people, cobots eliminate the need for guarding and no doubt will have greater roles as time goes on. Downing warns that cobots don’t solve every problem of interaction, however. “Using a cobot depends on the application,” he said. “If the process makes parts that have sharp points or rough edges, or if the parts are hot, you still can’t have a person working in that environment.” Even in cases in which a robot takes onmost of the machine-tending duties, workers are still necessary to keep an operation running. “You still need a person toget rawmaterial to themachine,”Downing said. “You might have an operator filling a hopper that feeds five or six machines, and he might do some quality control checks or some other value-added activity that isn’t easily automated.” This allows the fabricating staff more time to focus on areas that can’t be automated, such as using judgment to make decisions that aren’t easily automated. Although turnkey cells with robots or cobots are the pinnacle of automation, some fabricators might not be ready for such a big step. This doesn’t mean that they can’t find affordable automated machines to fulfill quite a few fabrication needs, even as they change over time. Innovo Corp. is an example of a small company that makes standalone machines that keep up with the latest trends relative to automation and process control. As machines run faster, tolerances become tighter, and manufacturers rely less on machine operators, standalone machines—like turnkey systems—can be outfitted with the latest in sensors and software to run more reliably without operator intervention. Innovo also uses design strategies that keep up with the times. For example, its machines usually incorporate a little more room in the frame than necessary, so if the customer needs additional capabilities in the future, the frame has some open space to facilitate modification.

FIA MAGAZINE | FEBRUARY 2021 21