Thinking J; I agree that asking the operator, or previous technician, why they think there is a problem, what they think the problem is, and what they have done to diagnose, or to fix, the problem, is time well spent. Sometimes the 'problem' is an attempted fix to a non-existent problem.
Ralphy Boy; ABB called their robot programming language ARLa; A Robot Language. I don't remember what Motoman called their programming language. Early robots used G-code, which I think is now entirely replaced by plain language type programming languages. Instead of a G-code move command, the syntax is usually something like 'MoveL' for a linear move, or 'MoveJ' for a joint move.
Naperlou; This was probably a Motoman - this story is several years old. Most of the robots were Motoman, either L100's or K100's, and one K6, but there were also two ABB IRB 60's, a Miller, a GMF S-420-F, and an ACMA. The robot had been moved from one building to another, and the workcell had been modified to allow 2 tooling fixtures. The 'programmer' (and this is a sore point) was a manager who fancied himself a 'robotic welding expert'. I had several disagreements with the 'experts' during my (short) tenure at Matsu. It is not unusual to have marginally qualified people program robots - one of the selling 'features' is how easy a robot is to program. Robots are easy to program, but not easy to program well.
Glenn... When working with CNC code generating software is common to have a 'post processor' that takes the general instructions from the GUI CAM screen and writes it as machine/controller specific code.
It looks like this is what you are referring to, or was it the onboard machine code that reads that that was modified?
Either way, I've done some post processor writing and I know that it is easy to miss something such as what you described... and not always easy to debug it later. It's the randomness of the problem you were up against that makes it tough puzzle.
Glenn thats really very nice ,i am highly impressed with your analytical and problem detection and solving skills.According to me a good engineer is not the one who just manufactures objects and products but he should have good analytical skills as well .
Glenn, your analysis of and solution to the problem were really good. You indicate that the robot had been reporgrammed site. Was this the only robot of this type in use at that site? What prompted the reprogramming? From your description it seems that the customer had people who were not qualified programming the robot. Is this the norm?
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