Mitsubishi’s new MR-J4 series sounds pretty smart. Its list of abilities provides a reminder that servo motors were one of the earliest examples of artificial intelligence, long before there was any real need for a Turing test. But the best item on the list, in my opinion, is probably not the one that dazzles most people who are thinking of buying one.
The thing I like about the MR-J4 is the “life diagnosis function.” It can tell you when it needs new bearings, when its ball screws are getting worn, and how everything is with its capacitors and relays.
You can just hear MR-J4 saying that its guide ways are fine, but it feels a little unbalanced when it comes to torque. The promise is that you can head problems off at the pass.
This isn’t really a new idea. In 2006, Mitsui offered a “remaining life diagnosis function” for its ship engines. Mitsubishi was working with “remaining life diagnosis technology” a decade ago, and people were giving papers on the possibility in 2001.
The object was to make automatic judgements about how long your engine had to live. It’s not surprising that much of this technological innovation was related to ship’s engines — that’s where servos got their start, after all, and the inconvenience of having a key part go on the fritz while you’re at sea dwarfs the inconvenience of having it happen in the factory by several orders of magnitude.
Engineers were always trying to guess — umm, foresee when a part might go out so it could be fixed or replaced at a convenient time, not just when it happened to die. The phrase “remaining life diagnosis” was picked up from medicine. It was the term used for answering the question, “How long have I got, Doc?”
“Life diagnosis function” sounds better than that. It sounds as though it could offer not just a guess on how long your servo has to live, but how all its particular parts are doing. You’d never again replace a motor when you could have just replaced a cable.
If you’re using Rexroth motion control, as we are, you still need human diagnostics. It’s also still hard to foresee when you might suddenly need a replacement. That’s why we are always available at (479) 274-8422 to help. We can often provide support over the phone. When that’s not enough, we can get to you quickly. We’ve got a charter plane on standby, and we make house calls.