Robot Waits For No Man When Recharging

Yikes, that power connector certainly wasn’t designed by Apple. Ugly as it may be, it’s the charging cable for a robot and acts as a sensor that allows the robot to properly align and plug into a power receptacle.

We’re going to go off on a tangent for just a second. We often think of the Rat Things from Snowcrash when considering robot power. They were nuclear powered (or something) and instead of recharging required constant cooling. Those day’s aren’t exactly around the corner but we think they’ve been realized in the lawn mowing robots that have a little nests to recharge in. Base stations work but they require the machine to return to the same place, or to have multiple charging stations.

The point is, this specialized cable makes base stations for robots obsolete. Now a robot can plug into any outlet it can get near, a great thing for robots roving large facilities. After the break you can see a video of this process. The robot arm zeros in by scanning horizontally and vertically and measuring the magnetic field put out by the AC in the wires of the outlet. Take a look, it’s a pretty neat piece of engineering.


49 thoughts on “Robot Waits For No Man When Recharging

  1. Slow,

    I feel like its overly complicated but I’m not an engineer. The nice part is that it can use existing outlets without modification. You could just use a camera and some sort of sticker to use as a reference point.

    I’m guessing its measuring the electromagnetic field. Will it still work with a double-gang box?

  2. I have been researching and programming in openCV for the past few weeks to try to build something very similar to this, As I woke up today to find this post, my dreams are a little crushed. Though my design is very different the concept is similar.

  3. I still think having dedicated docks is not a bad thing.

    For one thing you could easily make one that still allows you to use the outlet for normal plugs but that the robot can detect as it strolls by. (Think of a thin adapter that outputs an IR signal for the robot to detect and an “in use” signal when something is plugged into it.)

    For another thing it prevents “Well I’d like to use the closest outlet but the damn robot is charging in it.”

    1. Heh. I was going to say the same thing. After the decimation of humans and the rise of the robots, this will be their safety net…. unless they have solar panels…

  4. I think one big advantage of using the EM field instead of a camera is that no matter what color the plate is or if it has a special cover it can still find the hole. Plus even if you have a lame electrician its still cheaper to go back and flip them then buy base stations.

  5. I gotta agree with those saying vision. A standard socket is almost an ideal vision target – known shape and size, high contrast, planar, surrounded by an uncluttered uniformly colored plate. If you can navigate to within close proximity (as that robot does before engaging it’s plug-sensor) it should be a very straightforward vision problem.

  6. “that is silly, moving a huge arm to scan for the plug :-? … way not just moving the bloody sensor”

    Because you would then need another articulating arm to move just the sensor.

  7. “Heh, what happens when the electrician installed the outlet upside down? Methinks a vision system might be a better solution..”

    electrical code specifies the ground prong is on top, ie, ‘upside down’. But we like our smiley face outlets

  8. My iPhone, even with its mediocre camera, can do live QR Code decoding. Put a sticker above each outlet with the precise positions of each outlet (it’ll support any outlet layout, no need for fixed offsets), put a 50¢ webcam on the arm, and dart along the wall until it hits said sticker. Make a swift correction, and insert; done.

    This is hella cool, but not completely thought through in this use-case.

  9. Actually, the preferred way to install an electrical outlet is with the ground prong up. (upside-down) The idea is that if something metal fell onto an outlet with a loose plug – it would short out, potentially causing spark and fire. If the ground prong is up this situation is avoided.

  10. @dax: That’s what I was wondering. I’ve seen quite a few ‘smiley face’ outlets, however our new building renovation has them all ‘upside down’.

    Perhaps combine vision and EM sensing? Vision gets you in the ballpark (a few cm) then you take over with EM sensing. Vision could also help you get the orientation right (ie: baseboard outlets installed sideways.. )

  11. So let’s see some self-charging robots that use vision if it’s as simple as people make out.

    Surely all it needs is some lego, an arduino and a cheap webcam ;-)

    Sticking things to the plug socket is the wrong idea. Why should we modify our environment to suit specific self charging robots?

    Anyway, when the self-charging “it’s easier using vision to find the sockets” robots come along, I’m off to stick pictures of sockets on the walls to confuse them.

  12. Does it work if only one of the plugs is hot? or what if it is a double gang box with 4 outlets? I wonder if active RFID would be better, as you could describe the outlet as well, in reference to is it a single hot, which one, double gang of 2 hot 2 switched, etc. It seems to work well though, and who cares if it took <1 minute, as charging is likely to take an hour or more or several. during that time the robot is relatively useless. It could have some processing off loaded to it then, or do some number crunching to tune it's "world map"?

  13. That is a bit daft.
    What else is that robot going to be capable of doing other than charging itself up?
    At least if you stick a vision system on the arm it can do all sorts of things.
    It would be nice if the robot had two power packs, it could use one of them until empty then find a power point and leave it charging whilst using the second.
    The packs could have simple wireless to signal when they have re-charged.
    You would have to hope nobody steals the packs though!

  14. seriously, using only a camera makes it susceptible to all sorts of environmental factors, and tagging power plugs with RFID or stickers is kinda counter to the point of letting it charge wherever.

  15. an outlet is a pretty unique thing on a wall, so it does not need stickers – if it can recognize a sticker it can recognize an outlet since the holes have fixed dimensions and distribution just like reference spots on a sticker – hence we don’t need stickers.
    if there are vision systems capable of real time face recognition finding a socket is easy compared to that

  16. Put some small “feelers” on top and one side so the arm can run along the wall till it finds the side of the plate, then use the sensor to move into position. This way the robot is not wasting time (And battery life) moving to far to one side or the other. Otherwise very cool concept.

  17. I seem to remember an article in the early 1980’s, probably in Byte magazine where they showed a simple robot vision system that used a DRAM chip as the image sensor (64×64 bit?).

    The sensor was placed on the robot at typical wall outlet height and the power plug on the robot was a fixed distance from the sensor. The robot would look for the pattern of the wall sockets in the image it would acquire and then home in on the socket and plug itself in. Quite clever for its time. Can’t seem to find a reference to the article on the web though…

  18. I think I seen a robot that could find a plug on it’s own before.

    Another faster method then EM would be to get close with a camera and then use a laser scanner.

    I’m pretty sure this would be easy to add to asimo using just visual scanning and the tactile sensors.

  19. Pretty ingenious. doesn’t need anymore equipment then a slightly modified plug, amp and adc.
    Should be no problem making plugging in a much quicker action. I think this video was painstakingly detailed to explain the process. Several steps can be combined and positions calculated on the fly.

  20. ITT: posters that know more about engineering than Intel and MS combined.

    Personally I thought it was really impressive – the fast and pretty looking version can come later, the working prototype is good enough for now.

    PS: why not supplement coarse sensing with a camera?

  21. Hmm – this reminds me of another robot I’ve seen plugging itself in recently…

    It appears this robot IS using a vision system, but it’s accuracy was considerably lower than I expected. It gets the plug into the right area, and then keeps tapping it around at different offsets until it gets it right. Sometimes it’s quick, sometimes it tries for forever to make it right.

    This sensing system, while as described appears quite slow, was bang on accurate on the first try. I’m not so happy seeing a large copper conductor surrounding all three pins on that plug however. Sure it’s almost certainly safe, but the potential to have it short against one or more of the pins seems like a danger to be avoided in my opinion. Could they have achieved similar sensing results with just a ring around the exterior or using all three pins at once for the coarse measurements?

  22. “that is silly, moving a huge arm to scan for the plug :-? … way not just moving the bloody sensor”

    Because you would then need another
    articulating arm to move just the sensor.

    Another?, the purpose of the arm is to find the outlet and plug to it….

    it is a good idea but silly to my eyes …

  23. I think that, as usual, a combination of different sensors is the most effective solution. The robot could have a little map in its head detailing where all the plugs are, use vision systems to figure out where the plug is, and then finally use EM sensing to get it lined up just right.

    Alternatively, you could just have a speaker that screams “I’M ****IN’ STARVIN’!” until someone comes along and plugs it in to get it to shut up.

    As to the feeler idea, I don’t think that would work. I can’t do it very well and I’m sentient. I usually find myself about three feet from what I’m trying to manipulate (a light switch usually)

  24. @Eric, actually the grounding pin on top is the correct position. Outlets with grounding pins on the bottom have been installed incorrectly. Unfortunately, most outlets are installed incorrectly, so people assume that the ground pin on the bottom is right, when it’s not.

  25. I lived in an old house once, one with METAL plates on all the plugs. That, in addition to being installed incorrectly.

    During our tenancy, the center screw on one plate had worked its way loose. I went to unplug the (thankfully empty) power strip, and the plate fell off. ZAAAPPPP!

    The prongs cut a slot in the plate. Apparently the fuse box in that house wasn’t wired correctly either. Now, if the ground pin had been on top, all would have been well.

    The electricity in that house regularly blew out 100 watt bulbs, and even BLEW UP a CFL bulb once. That was a bitch to clean up.

  26. I guess you guys failed to notice that the Barrett Hand is actually gripping the plug, it is not permanently attached. When it needs a charge it probably grabs it off of some kind of holder, much like some CNC machines change tools automatically. Look at other Intel videos on youtube and you will get an idea what they are trying to accomplish.

    Keep in mind that Intel is not trying to make this an actual product yet, this is just for research. Until Skynet is up and running.

  27. So you are saying that my phone can take a picture of some random object (or scan a barcode), figure out what it is, and take me to the website of a product, but a robot can’t visually detect a power outlet and plug itself in?

    This person is making it magnitudes harder than it actually is. He should have looked at the code and seen that recepticals all need to be mounted at a certain height and certain distance on a given wall. then take a picture of the wall look for the contrasting areas and you should be able to find the switch. Use visual or feelers or whatever to find the switch plate (the sizes are all standardized!) and plug in.

    Of course there are always exceptions but recepticals are the same in 99% of locations.


    People claiming that ground pin up is the right are incorrect, it is not specified anywhere. Seeing as most electrical devices are built assuming ground pin down I would stick with that:

    Another source: Black and Decker Complete Guide to Wiring 4th Edition (specifically the recepticals pages)

    It seems much safer to have a “wall wart” hanging out with the heaviest part down rather than upside down exposing the live connections.

  28. What’s with the whole vision instead of thing? What aw of physics prevent multiple sensors being used? Good thing it’s not designed by Apple, less fetures for more cost!

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