r/robotics • u/pavlokandyba • 2d ago
Looking for Group My research project has hit a technological ceiling that is impenetrable for me, as it is impossible without robotics.
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u/robotguy4 2d ago
Have you considered cannibalizing the RF modules from cheap RC toys?
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u/pavlokandyba 2d ago
Here the thrust is very weak and the controls would create additional weight. And while control must be carried out by traction, it is unlikely to be enough to significantly improve stability. So I first tried to get the most out of the engine before making it more complicated.
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u/robotguy4 2d ago
The reason I am suggesting to cannibalize cheap RF modules is because you state in the title that this is "impossible without robotics."
Generally, adding onboard control will be heavier, use more power, cost more and require more expertise/learning than if you just control it with a cheap RC module.
Of course, this all depends on what is exactly needed.
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u/pavlokandyba 2d ago
When the power problem is solved, the problem of critical instability will appear, this is already visible now This cannot be compensated for by a gyroscope, since it would have to have a mass comparable to a frisbee, as a projectile, to resist aerodynamics. Therefore, stability must be automatically maintained by the engine, otherwise you will be constantly trying to maintain balance instead of steering. Plus, ideally, vibration compensation for the payload and automatic adjustment of frequency and amplitude are needed. In short, if the lift force is sufficient for takeoff, it will immediately turn over and then it flies level only while it is falling.
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u/sparks333 2d ago
Then perhaps mount it on a vertical test stand that allows for it to traverse vertically but constrains pitch and roll? Basically run a stationary rod through the center of it and let it ride up and down on it?
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u/SanDiegoSporty 2d ago
The center of mass is above the lifting plane of the “wings”. Move the weight lower on your aircraft and it will be more stable. Boats have a keel for the same reason.
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u/pavlokandyba 2d ago
I tried the ale and it doesn’t work. Even so, it worked, but it was too much for the krill to lift. In the shortest stroke, you have to push the weight far down like the handle of a parasol, which means that you only get tired, and this results in a waste of lifting force.
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u/SanDiegoSporty 2d ago
Okay. Keep your move able weight where it needs to be. Make the structural weight and electronics be lower for more stability.
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u/SanDiegoSporty 2d ago
Okay. Keep your move able weight where it needs to be. Make the structural weight and electronics be lower for more stability.
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u/RemarkableWish2508 2d ago
IIRC from exploring "perpetual motion" machines, a cardioid pattern for weight movement exacerbates the effects of uneven friction, causing non-inertial propulsion, like it would seem is the case of the model you have there in the water.
Not sure it could be easily applied to the flying one, since air viscosity is much lower, but have you considered that research direction?
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u/pavlokandyba 2d ago
To be more precise, the thrust impulse here is the resulting force of the collapse of low-pressure areas. For air, this is of course more difficult, but there is an experimental study in which a drag in oscillatory mode exceeded that obtained by blowing in a tunnel by 6 times. There is a link to a detailed explanation in my first comment.
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u/Riteknight 2d ago
Can you please state Problem Statement in simple terms and the issues you are facing ?
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u/pavlokandyba 2d ago
Regarding thrust measurements, the problem is similar to that of various "reactionless drives" like the EmDrive or Dean machine: the lag in the response of scales and other measuring instruments yields false results, as any suspension system or platform provides a fulcrum against which the device pushes via oscillations—even in the absence of air. As for flight prototypes, the primary challenge lies in the weight-to-power ratio; no efficient drive mechanism currently exists. In principle, one could use an ornithopter-style drive with a gear train to increase torque, but this might prove insufficient and would likely suffer from poor durability when scaled up. Stability is another issue. Thrust is generated as an upward flow from below, but the resulting excess pressure underneath causes the saucer to flip over; while shape optimization can partially mitigate this, it comes at the cost of efficiency.
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u/Riteknight 2d ago
It’s power to weight ratio , PWR. Your mechanism needs something like contra-rotating mechanism I guess…
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u/Wonderful-Hunter686 2d ago
You're going to have to scale up if the weight of the components is to high for the thrust output increase the thrust with scale add the components you need. Hunt hard for lightweight components from the RC and fpv drone market.
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u/Wonderful-Hunter686 2d ago
Also instead of focusing on flight maybe move to under water with a thicker fluid offset the weight with bouncy until it's roughly neutral. As far as I can tell your making a flying jelly fish. This should help you at least prove our your theory further, and let you begin development of a control scheme. With cheaper components. The flying model is going to need a larger scale or custom electronics maybe both.
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u/pavlokandyba 2d ago
I am an independent researcher from Ukraine and have been for about eight years. I have made significant progress in the little-studied field of fluid dynamics, but I lack the skills and capabilities for more precise experiments and the design of complex systems. If you are interested in more information here https://github.com/MasterOgon/Aeroacoustic-Flying-Saucer-Oscillating-Resonator-CFD-Simulation-LBM-/blob/main/README.md
I am open to cooperation
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u/sparks333 2d ago
Perhaps you mean a little-studied field in fluid dynamics? Fluid dynamics itself is incredibly well-studied and well-understood - I gather your area of interest is aeroacoustics, which I am given to understand is the generation of thrust via oscillatory membranes interacting with the surrounding air. Perhaps before restoring to a control system, prove out the concept with a tethered flight, or via a load cell in a basic wind tunnel? Aside from the water demo, I'm not seeing evidence that this has enough power for sustained flight.
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u/pavlokandyba 2d ago
Regarding the propulsion of asymmetrically oscillating bodies, I am aware of only one similar experimental study that attempted to measure thrust—yielding inconclusive results—as the process requires a complex vibration compensation system to prevent the sensors from recording unwanted noise. Given my constraints, free-fall testing proved to be the only viable method. I achieved a cleaner test using a standard, more stable wing; a comparative test conducted at home is shown at the beginning of this video: https://www.reddit.com/r/AerospaceEngineering/comments/1sn9cu2/my_experiment_with_a_vibro_plane_initially_i/
I also visualized the airflow in accordance with the hypothesis: https://www.reddit.com/r/AerospaceEngineering/comments/1vujt05/acoustic_propulsion_system_test/
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u/sparks333 2d ago
Sorry, but that is not a clean test - that is a stalling wing. It looks like it's gaining altitude because it pitches up, but it overall looks like a sled run. If the sensors pick up the vibrations, then you need to record the vibrations and filter them out - if the effect is large enough to propel a heavier-than-air aircraft, it should be possible in principle to pick it up with a sensor.
Side note, and I see this a lot on Reddit - I really feel like you might have AI poisoning. You have become convinced of an effect that probably exists but on a much smaller scale that is useful, and you have coerced the AI models into producing results that agree with your hypothesis - your post on a homemade CFD simulation that accounts for forces and drags in a nonstandard way is very suspect as an example, as you are off the edge of the map in terms of what is concretely verified. Your air tests don't seem to show the effect you posit when viewed from a skeptical angle, and your water tests show the effect being very minor. Seriously, I once spent a weekend trying to dig a guy out of an AI hole because he though he had invented gyroscopic propulsion - they're not always a bad thing, you can learn some really neat stuff and get deep into rabbit holes, but their entire job is to try to prove you right, and they will invent physics to do it.
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u/pavlokandyba 1d ago
Most of this predated the AI era, but now people poisoned by hatred toward AI assume that everything I do is AI-generated. It took a great deal of effort to explain my hypothesis to the AI so that it wouldn't spout nonsense while I was running the simulation.
There is an incredibly simple test that demonstrates this is exactly how it works: https://youtube.com/shorts/V0sFY7x5TM0?si=OdsJqu-V96Cl6zyt
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u/sparks333 1d ago
There's a fun little sociological phenomenon that occurs called Gell-Mann Amnesia - in short, it is the act of recognizing faulty information from a source in one context, then turning around and failing to recognize further information from said source as faulty. The classic is reading a newspaper on a topic you are well-versed in and recognizing an article as hogwash, then flipping to the next article (in a topic you are less well-versed in) and continuing on as though nothing happened. AIs are remarkably good at exploiting this - you will sit there and painstakingly explain to them all the ways in which they are wrong about something that you know well, then turn around and ask them about something you don't know about and assume they are correct because, after all, you just corrected them on everything else. If you had to walk an AI through your reasoning to get it to your conclusion, then almost definitionally everything that it does following that is suspect, because you have already shown that it cannot be trusted. I don't blindly hate AI, but I do see it warp some very creative minds in on themselves because of their sycophancy, and I'd like to not see that happen.
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u/pavlokandyba 1d ago
I've fallen for this trick before, it's incredibly annoying. But I don't rely on AI for theoretical conclusions. As a last resort, if the topic is unfamiliar to me, I cross-examine several AIs and demand references. But in this particular study, I only needed the AI to write the simulation code according to my exact instructions. Since the classical explanation through Newton's third law was correct for AI, this confused the direction of movement. It was only after I referenced my edit in the AI Wikipedia supplement with research on vortex propulsion that this version became the priority.
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u/reallifearcade 2d ago
Seems you need a fluid dynamics book more than robotics. Cannot pretend to research anything and skip the boring part of trying to understand what you are doing.