Umbrella Drones — Jellyfish Of The Sky

Mount an umbrella to a drone and there you go, you have a flying umbrella. When [Alan Kwan] tried to do just that he found it wasn’t quite so simple. The result, once he’d worked it out though, is haunting. You get an uneasy feeling like you’re underwater watching jellyfish floating around you.

A grad student in MIT’s ACT (Art, Culture and Technology) program, [Alan’s] idea was to produce a synesthesia-like result in the viewer by having an inanimate object, an umbrella, appear as an animate object, a floating jellyfish. He first tried simply attaching the umbrella to an off-the-shelf drone. Since electronics occupy the center of the drone, the umbrella had to be mounted off-center. But he discovered that drones want most of their mass in the center and so that didn’t work. With the help of a classmate and input from peers and faculty he made a new drone with carbon fiber and metal parts that allowed him to mount the umbrella in the center. To further help with stability, the batteries were attached to the very bottom of the umbrella’s pole.

In addition to just making them fly, [Alan] also wanted the umbrella to gently undulate like a jellyfish, slowly opening and closing a little. He tried mounting servo motors inside the umbrella for the task. These turned out to be too heavy, but also unnecessary. Once flying outside at just the right propeller speed, the umbrellas undulated on their own. Watch them doing this in the video below accompanied by haunting music that makes you feel you’re watching a scene from Blade Runner.

Also interesting was that in some countries he couldn’t fly his jellyfish due to drone restrictions. Fortunately the FAA clarified their rules regarding drones just in time for him to be able to fly them in the U.S.

But this isn’t time we’ve seen flying umbrellas. Check out this delta kite made using an umbrella, and though tethered, there’s also this umbrella-based windmill.

[via Popular Science]

41 thoughts on “Umbrella Drones — Jellyfish Of The Sky

  1. UAV developer here… I’m a bit skeptical of this. If there is an umbrella over the rotors, where is the airflow coming from to provide lift? If it sucks it up from around and under the edges of the umbrella, that would provide a downward suction that would cancel much of the lift being generated. I won’t straight out say it couldn’t work, but it would have to be hella inefficient flying with obstructed rotors.

      1. Why not just use the coanda effect and mount a squirrel cage on the top to blow air outwards and consequently downwards as it follows the shape of the umbrella. Then use some actuating surfaces on the edges to adjust attitude.

      1. I feel it kinda fails at both. I was expecting something that actually used an umbrella shape for thrust.

        Do you really need to go to university to learn how to glue something onto something else to make something with no use?

    1. You can even see this happening in the video. When the umbrellas are rising, the edges of the fabric are drawn inward toward the center as air is sucked in along the sides. On one hand, this contributes heavily to the undulating effect that the designer was aiming for. On the other, I agree it must really hurt efficiency. As [dassheep] suggested above, I would go with gauze or mesh fabric panels on at least part of the topsides.

    2. the fans pull air from around the top, not from a column straight up. there is some space between the props and the umbrella. I would expect a slight vacuum the closer the props get to the umbrella’s mantle (?), lower its efficiency until it doesn’t work anymore.

    3. Or you could cut holes in the umbrella and glue on some simple one-way flaps on the underside. They’d flap open on the rise and close on the fall, making it fly better and still fall slowly.

  2. Apart from the awful saxophone sounds.. Less ‘haunting’ and more ‘drunk street performer’.. It’s neat!
    Way too much wobble and judder, but I can see the effect they are going for! Tune the flight further and make them more graceful and it’ll be neat to see these ‘fly’ over a city as a swarm/cloud/’whatever the plural for jellyfish is’

  3. Just two suggestions for improvements, 1) LEDs in the umbrella, fly it at night, instant UFO, 2) Mary Poppins foam cutout hanging off handle, fly it in the day, instant WTF!

  4. A challenge:

    have a circular hole in the middle of the umbrella. Therein, a pair of counter-rotating (coaxial) propellers.

    Now the umbrella works as a fan duct. Might, just might work :-)

    If we’re lucky, we could (mostly) dispose of the umbrella’s spokes (or just make them much thinner and wobblier), since air pressure might suport the whole thing. Or just go for a thin, inflatable structure. Even lighter.

    1. way too complicated… there is a better way which allows you to keep most of the umbrella ;-)

      They sometimes call it a “Coanda effect lifter”, the air flowing over the surface creates a low pressure zone, causing lift…

    1. I agree in the general case mounting the mass below the rotors doesn’t affect stability because it’s basically a pendulum rocket, but I think there’s more to this case. In this case the umbrella is a source of lots of aerodynamic drag away from the centre of mass, which could induce a moment on the craft. My intuition is that this would make it more self-righting when descending (like a parachute- drag above mass) but more unstable when ascending. It would also tend to resist lateral movement because the drag on the top of the craft would tend to return it to a vertical position when moving sideways through the air.

      Normally I’d agree it’s a simple case of pendulum rocket fallacy, but the additional drag element here might actually result in a more stable craft.

  5. Not a drone designer but a diver – if he’s trying for something like “air jellyfish” he’s got it wrong.

    Jellyfish propel themselves upward (slowly) by constricting their hood and pushing water down. He’s doing the opposite by pushing the “hood” up from underneath which is neither stable nor efficient. Result – wobbly…with Bladerunner soundtrack. That’s not art, though the artists statement will no doubt make up for it. All snark aside it’s several more than I’ve built so he gets points for trying it out.

    Could you make a floating jellyfish that propelled itself that way? Certainly – if it were nearly neutrally buoyant as jellyfish are (you’ll need some helium). It’s been done, and looks like this: https://youtu.be/F_citFkSNtk

    1. Please watch the video again. He’s not pushing the the “hood” up while ascending. Under hard vertical acceleration the “hood” will actually suck in because the umbrella is restricting the amount of air the props can pull in from above.

  6. A Coanda effect lifter is better suited for this, instead of fighting the aerodynamics, you can have them help you…this nicely shows the difference between “artist” and engineer :D

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