Hi
This may sound crazy. How about a quadcopter designed for underwater use. Brushless motors operate perfectly well submerged and the rest can be waterproofed quite easily. Idea being that one would use small props, basically the quad would operate in a different medium but essentially it should still stabilise as it does in air. I thought about escs (which don't like water) getting hot but they could be exposed, covered with tectyl or some other waterproofing spray.
As a fail-safe, waterquad would be slightly buoyant so in case of power loss, it would merely float to the surface. One would then have keep throttle on all the time to stay submerged and power up to sink as opposed to normal operation. I know that 2.4ghz does not work underwater but the older 35mhz systems do. For fpv, 1.3ghz could be used ?? Also I wonder which flight controller would work best, kk2 maybe for cost-effectiveness.
Has this been attempted before and if so, any success? Couldn't seem to find anything on this concept. I'm itching to start building but somebody please stop me if I'm wasting my time.
Replies
There are some new quadcopters that claim to go underwater, I think you can find them in Kickstarter. One solution to communication is a floating antenna, this will keep you in contact. Managing the cable will be one of the challenges, good luck, I think this is something that could be really great and FAA could not regulate.
The only question I have is why a quadcopter? what issues with typical submersibles would this solve. A quadcopter in air is easier to fly, can turn in a very short radius, hover, and other practical aspects that other aerial vehicles cannot do.
i think these might be the advantages
1. Its a hybrid which will do both the workings of quadcopter and a submersibles.
2. we can reach distant place more faster through air than in water.. once we have reached the distance we can dive into the water.
3. i have thought of giving it a robotic arm. which could do some once its submerged..
what i am doing is just a prototype.. a small step into world of new kind of vehicle..
as we all know 70% earth is covered with water.. and i think this kind of vehicles will be required in the future..
there might be few other applications also.. that we just have to find out..
You would be better off having a quadcopter that carries a subersible on a retractable tether to/from a remote location.
Underwater and the air are so different that a craft that could do both would be so suboptimal in one or the other to be not worth it.
well sort of that's what you'll end up with but by sharing the batteries, (possibly motors) and the control gear you will save a good bit of weight and unnecessary doubling up on the gear...The bit left on the surface (ie the float) can have the batteries in and a receiver but is otherwise dumb...
Power loss over a tether is significant, you can't just have the batteries in the float.
ah yes good point unless you step up to high voltages ect but that adds another level of complexity. With the craft being near neutral buoyancy the batteries can be in the craft with no real loss to anything.. maybe a small one in the float to run the coms and then keep the tether to fiber optic...
you need to use low frequency 3-300 khz TxRx that do not exist for sale to the public wifi variant is being made but expensive, second option is to use communication relay floating a devise on the surface of the water for communication wireless wired communication in water last is all tethered.
http://www.dspcomm.com/l/aquacomm-underwater-wireless-modem.html?gc...
you can make low frequency RF links its not that difficult but the antennae lengths start getting ridiculous to get any reasonable distance. Again though you set up a perfect 300 hz RF link with a county length antennae and you still wont get the data through put for live video....
The link you've posted OG is for ultra sonic not RF. And yep there sis no doubt this works but as I said in my post a few up , the data rate is pretty poor unless you pay big money and even then it's not great...
can we use same propellers which we use in air?? doesn't it have any negative effect? i mean torque required and also the load on the motors?
Wow.. lot of things you have been discussed.. which indicates that its almost impossible to have underwater wireless live video transmission using present technology.. i think then i have to go with your favorite idea.. which is i think more than sufficient for my project.. but i will keep on searching for wireless high speed communication.. one or the other day it should be done..