The one they used where I worked used a system they called "Vision". A camera that took a picture and compared it to another picture on a computer. They also used "Vision" to measure terminals being made in a die/press this was done with the press making ~1300 parts per minute. It would shut the press down withing ~10 parts when a problem was found. Don't know if "Vision" was something they bought or came up with themselves.But the hardest part would likely be calibrating the actually placer. Pick it up a bit off and it would be out of place. It would be nice to see how the real ones do that.