At the horseshoe-shaped assembly line in Youngstown, Ohio, engine parts move like clockwork on a conveyor with 60-second takt time for each station, leaving no room for error. As the engine cradle sub-assemblies reach the end of the line, the company needs to inspect that each sub-assembly, which includes a critical steering-gear wire harness connector, is fully seated and locked. “If there is an intermittent loose connection or it’s connected and not locked into place, it can cause an intermittent or complete loss of the power steering, which is a level 8 on the severity scale,” says Mike O’Keefe, value-added assembly superintendent at Comprehensive Logistics. “It’s a life-threatening failure mode, so we need to make sure that those clips are locked into place with 100 percent confidence.” O’Keefe also explains the challenge. “Industry-wide, manual inspection is only about 80 percent efficient, so we were looking for repeatable quality inspection through an automated system,” he says.
This process was causing the Ohio manufacturer headaches, however, as the stationary multi-camera system the company implemented couldn’t position cameras into tight spots and wasn’t as repeatable as the manufacturer needed. “The data gathered by the camera system wasn’t as pure,” adds O’Keefe, who also experimented with a probe-style robot that did not meet repeatability requirements.
The company started researching alternatives. The solution would have to support Comprehensive Logistics’ up-time requirements, be simple to use and had to integrate easily with the processes and people on the line. “We had to find something that wouldn’t contribute to a potential safety issue,” explains O’Keefe. “We looked at Universal Robots and quickly realized that this was a cost-effective, light-duty robot that could move a vision camera to the right positions safely and repeatably. The dexterity of the Universal Robot enables it to get underneath where the mission-critical points are and be 100 percent repeatable.”