Letting Robots Manipulate Cables
This looks cool, but it also looks like the only type of cables they&#x27;re using are copper wire cables.<p>I used to work at a hardware company that made and sold fiber optic switches with hundreds of input and output ports.  I worked on calibration and test software for these things.  Step zero to testing and&#x2F;or calibrating one of these beasts was to hook it up to a custom-built rig we built that ran the software I worked on.  This, of course, involved plugging in hundreds of fiber optic cables.<p>Besides the difficulties mentioned in the article, fiber optic cables have an additional property that makes them hard for robots to manipulate: inside the plastic jacket, they&#x27;re literally made of glass.  So, you can very easily break a cable, rendering it useless until repaired.<p>When we detected a likely broken cable, we had a neat method of finding the exact location of the break.  We&#x27;d take a very bright (10 mW) red laser and shine it down one end of the cable, and see where the bright, red spot appeared on the cable jacket.  That spot would be where there was a lot of red light leaking out of the cable, so, that would be where we cut and re-spliced the cable.<p>The other difficulty is that for a robot to be practical in this use case, it would need to be able to deal with the fact that there are hundreds of cables around.  Because they are fragile, and any significant bend in the cable can introduce optical loss, you don&#x27;t want to just willy-nilly go plugging cables in and not worrying about how they lie.<p>Oh, and, probably the hardest thing for this type of robot to deal with would be the fact that the cables were not all equivalent.  Our rig had an infrared light source on it that powered the whole shebang.  Each light source had something like 8 output ports that were very, very bright.  I don&#x27;t remember exactly how much power they put out, but, in spite of not being coherent sources, they were very bright on the IR test cards we used to check and see if things were lit up. Each output port from the light source went into a custom splitter we made that gave us hundreds of light rays that were each just a few percent as bright as the original 8 output ports.<p>Each of these light rays traveled down a single cable, and we had the capability to turn them on and off individually through some clever optics.  That meant we could literally light up one out of the several hundred cables, send that light through the switch, and then measure where we expected those photons to come out.<p>We needed that capability for several of our tests.  This meant that the individual cables were not interchangeable!  They were, in fact, labeled, as were the input ports on the switch, so we knew we could plug, say, light source cable 57 into input port 57 on the switch, and then look to see where the light would come out, and how bright it was.<p>Because they are optical cables, they need to be cleaned of dust before they are plugged in, as well. The whole setup was in a room with HEPA air filtration that approximated a clean room, so there was not much dust, but there was certainly some.  If a speck got on one of the connectors, it could really screw up our optical loss measurements.<p>Because of these difficulties, even if a robot were available that could handle a small number of copper wire cables, I suspect such a device could not deal with fiber optic cable.  As a result, our solution was to have interns do the job of connecting and disconnecting the switches from the test&#x2F;calibration rigs, and avoid disconnecting them for as long as was practical. This is why our rig was both a calibrator and a tester.<p>If you think about how long this would take to accomplish, consider that cleaning the connector might take ~1 second, and plugging it in to the right might also take ~1 second.  Multiply that by 100, and you get 3 minutes per 100 cables.  As I mentioned, these beastly machines had several hundred ports.  And, besides plugging the light sources into the switch inputs, we had to plug in output cables that lead to an optical power meter on the rig.  All in all, around 750 cables would need to be cleaned and plugged in in order to hook the switch up to the rig.  3 minutes &#x2F; 100 cables * 750 cables is about 21 minutes, which would be about the theoretical minimum amount of time it would take to prep the switch for testing.  In practice, it took anywhere between about 30 minutes to an hour.  Unplugging the switch from the rig took about half that.  So, that&#x27;s about 45-90 minutes involved in total, just to hook the switch up to the machine we used for testing and calibration!<p>Unfortunately, it meant that we were employing people to do this for a large portion of their day.  We were near a university with a decent math department, and, for some reason, the person who hired interns there really liked to employ math majors.  So, we had 2 or 3 college math majors we employed in large part to plug cables in and unplug them when we were done.<p>I think it is fair to say that particular job will probably not be automated away any time soon.