When I did phone support for a barcode scanning company I had one customer trying to use an undecoded scan engine to guide robots across a floor. A scan engine

When I did phone support for a barcode scanning company I had one customer trying to use an undecoded scan engine to guide robots across a floor. A scan engine works by sweeping a laser across the barcode and using the light intensity at different points to determine where the bars and spaces are relative to each other. A modern scan engine will usually output what data was in the barcode, but an undecoded scan engine outputs a continuous stream of data indicating the light intensity received from the laser. If I recall correctly, they had a bunch of timing marks on the floor that the robot would follow, and they were scanning these using the engine. You could keep a robot on-track in this way because, if the laser is angled relative to the timing marks a large part of the sweep isn't going to contain any marks and so the robot needs to correct. Then it's just a matter of servo'ing down the line. I would never have thought to do something like that so it was probably the best call I'd gotten all year.