Helicopter Seed Robot Can Also Drop Like A Rock

Whether you know them as samara seeds, maple seeds, or helicopter seeds, most of us know the seeds that spin down to the ground on one or two blades. They have been served as the inspiration for several robotic autorotating gliders, and researchers from the Singapore University of Technology and Design (SUTD) can now also make them dive rapidly on command. Video after the break.

In the previous versions, researchers showed that they were able to steer the SAW (Samara Autorotating Wing) by actuating the trailing edge of the blade with a servo. It takes input from an onboard 3-axis magnetometer and GPS, and adjusts the control surface continuously depending on its orientation to make it fly in the chosen direction. The latest paper (PDF) focuses on the craft’s new ability to switch from autorotation to a rapid dive and back to autorotation. Named the dSAW (diving SAW), it can drop like a rock by changing the control surface angle to almost 90° the wing to stall it. It exits the dive by simply moving the control surface back to the normal autorotation position. The kinetic energy built up during the dive is converted to rotational energy very quickly, which slows its vertical velocity to almost zero for an instant before settling back into its normal glide.

We can certainly see this being useful where the dSAW needs to quickly lose altitude to avoid being pushed off-course by the wind. The video below demonstrates this by dropping three dSAWs from an RC airplane. On command, they spread out, each in its designated direction, and then repeatedly switch between dive and autorotation mode as they descend to the ground. The researchers envision this being used to scatter sensor units over a large area in a controlled fashion from a single aircraft. What would you do with this technology? Let us know below.

31 thoughts on “Helicopter Seed Robot Can Also Drop Like A Rock

  1. Now it just needs one of those small Co2 canisters to power a rocket tip so it can spin itself up for powered flight… I doubt even those tiny canisters of huge pressure would give it all that much lifting time, and being a reasonable additional mass probably needs the whole thing scaling up slightly to actually be powered flight over falling with at best a little more style…

    But it would be good fun to see one of those things rotodyne their way back up… And even a tiny amount of forced spin lift could be very useful for letting these things spread over the area they are supposed to, and those little carts are pretty cheap and safe. Though I’m not sure the control electronics or servo could actually handle that sort of rotation speed or the generated air pressure on the control surface – getting the rocket tip force correct so it will spin up enough for lift but not soo fast the electronics can’t handle the update speed needed to maintain directional control or making the servo unable to take the load could be fiddly – simple enough to trial and error though, after all the rocket tip is just going to be a tiny hole in the end of a pressured tube..

    Also as long as the geometry of the blade(s) is such that it will spin up and lift even with the servo unable to do anything it works. So use the rotations own force to lock the blade into a lifting position, then just let it rip (either till out of gas or you close the tap) and once the rotation speed comes back down – which won’t take long it can continue to control its fall.

    1. multi-launch precision guided bombs. figure they would be good at anti-personnel and anti-structural. perhaps an anti-vehicular bomb as well, but that’s difficult because most vehicles could outrun it. you would have to come in from above to avoid visual detection and drop. they could be scaled up or down as needed and the simple design makes them cheep. of course i think a military version would come with some kind of propulsion for periods of significantly higher performance, and on larger models steady state high performance. mainly the ability to regain altitude, increased horizontal maneuverability and limited loiter capability. imagine hovering bombs over an enemy encampment and force a surrender by making the only other option immediate and decisive destruction. or in situations where you need to kill 3 separate targets in 3 different locations at precisely the same time.

  2. I’ve always thought a maple seed would be a good model for electronic fireworks. Imagine smaller versions of these gliders, each with one or more RGB LEDs. Once a pre-programmed display sequence had completed, the gliders would autorotate to a large funnel guided by an IR beacon or similar, where they would be wirelessly recharged and given a new display sequence, then configured to “drop” mode for re-launch by a pneumatic cannon or maybe a railgun.

  3. It seems to me that this technology would have great use in place of parachutes. This would allow faster descent onto enemy areas and still provide the lift when near the earth. Further, it wmy also have application for engine faiure in aircraft and helos on a much larger scale, of course.

  4. A very well researched and executed interpolation of several ideas that were first discussed on HAD I believe, around the time there was interest in disposable cardboard autonomous aircraft for emergency aid drops etc., and how to minimise the number of parts.

    1. I don’t agree, bombs should travel fast to avoid any possibility of interception, and are deployed from large heights for the safety of the bombers. They can already steer several km to their targets.
      This would be ideal for dispersing sensors for a few km from a mortar, etc.
      Smart bomb might make sense for anti-personnel/assassination devices, but again there are better options.

  5. Although its obvious intent is military (otherwise they wouldn’t use a C130 in their diagram) it’d make a fun toy. Put a hook on it and use a slingshot to get it to altitude whilst in its drop state, then have it enter spin state at the top of the arc. It may not need any smarts at all, just a spring catch that releases the blade after a few seconds. I have a feeling I’ve had a toy glider like this long ago, but not a rotating wing just a regular planform.

    1. The C-130 was actually a remote controlled scale modle of a C-130 that they tested dropping from. I’m not sure if they intended the military connotations, it might have been the only RC aircraft they could easily use.

  6. To confirm suspicions about the intent of this, the project was partially funded by “Temasek Laboratories @ SUTD”:

    “Temasek Laboratories @ Singapore University of Technology and Design (TL@SUTD) was established collaboratively between the Ministry of Defence (MINDEF) and the Singapore University of Technology and Design (SUTD) in October 2012 to undertake cutting-edge research and development for potential defence applications, while building up both technical and human talent capabilities in critical research areas.”

    From https://temasek-labs.sutd.edu.sg/about

    1. It is so sad and depressing how much effort (and money) humans invest into killing each other. Imagine if all this would go into other projects like fight global warming, deseases (virus anybody?), …

  7. I’m thinking that it may be a good idea to use this for planting trees? Since it is able to dive, it may be useful for planting seeds into the ground. Imagine planting tens of thousands of trees at once just by flying a cargo plane over the area. Probably very useful for planting trees in inaccessible areas.

    On the other hand, it can probably be equipped with sensors for detection of wildfires. Maybe dispersing these sensors in forests and jungles that are prone to fire, connect them with LoRaWan, and you can have a monitoring network for wildfires.

    Restoration of nature seems to be an appropriate use for this technology since it is inspired from maple seeds in nature.

    1. The seed vessels used by Droneseed accomplish this without any technology onboard. Each drone flight carries ~25kg of seed vessels to replant 3000 square meters. In the case of your idea, adding a few of these with sensors on each drop would add another layer of data for all the land they replant. The only downfall is that the device would need to be recoverable to keep in line with the eco-friendly concept of Droneseed.

      1. I think what YR meant to say is large-scale affordable reforestation.

        Droneseed can roughly carry 250 seeds each flight (~100g each ‘pod’ and 25kg payload). This is hardly scalable given the flight time limits and range limits of a conventional multi rotor. Think about the number of batteries you need to keep recharging on the ground for an operation involving like 5-10 of these drones.

        Using a long range fixed-wing UAV / actual aircraft, these autorotating devices can be deploying sensors/seeds in places where it is inaccessible for man / normal multi rotors can reach.

  8. It may be a good idea to use this for planting trees? Since it is able to dive, it may be useful for planting seeds into the ground. Imagine planting tens of thousands of trees at once just by flying a cargo plane over the area. Probably very useful for planting trees in inaccessible areas.

    On the other hand, it can probably be equipped with sensors for detection of wildfires. Maybe dispersing these sensors in forests and jungles that are prone to fire, connect them with LoRaWan, and you can have a monitoring network for wildfires.

    Restoration of nature seems to be an appropriate use for this technology since it is inspired from maple seeds in nature.

  9. This could make an amazing sci-fi tool / weapon in war when you consider that one of their wing designs was pretty close to a hexapod leg, what if it was? could be a stack of legs that fold to form the body or maybe even some crazy version that has multiple of these interlocking?

    Would go something like this:
    1) release a few from a plane, make em spin and move outwards, use lasers to get a basic 3d map of area
    2) slow down spin and move back together while, using camera’s (of different types?) to get more information about the area (surface types, object types, etc)
    3) move back together and go into ‘drop mode’
    4) right above ground deploy parachute (or go back into rotate mode & be built to take the impact?)
    5) fold out as hexapods (or interlock?) and map area (and depending on size they could do this at, weaponize? :P)

    Somebody that writes sci-fi please take this idea ;)

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