When I worked at the Oshawa Truck Plant on the GMT 800 project, I received a complaint that a robot was denting the floor pans. The floor pans were presented to the robot from an overhead conveyor. The robot picked the floor pan from the conveyor and transferred it to a carrier that moved it through a series of stations.
The locating holes in the floor pans were about two inches in diameter. The locating pins of the robot gripper were about 3/4 of an inch in diameter. After the robot gripped the floor pan, it moved with 100 percent acceleration. The floor pan slipped in the grippers, and the locating pins dented the sides of the locating holes.
My suggestion to the engineer was to reduce the acceleration profile enough that the floor pan would not slip in the grippers. This would increase the cycle time by several milliseconds, and was rejected by the engineer.
Sometime later, the line electrician asked me why I couldn’t come up with a fix for the denting of the floor pans. I told him that the engineer had rejected my suggestion. I explained the acceleration parameter to the electrician, where to find it, and how to reduce the acceleration. The electrician then reduced the acceleration profile and the denting stopped.
I didn’t get any complaints about increased cycle time.
Glenn Aitchison's first field service job was in 1987. Since then he has worked in the robotics, automotive, and industrial automation and machinery industries. He received his Certificates of Qualification as an Industrial Electrician and as an Industrial Mechanic (Millwright).
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