Hello all!
I am working with an emergency response group and they are looking for ways to explore caves using a drone (probably a quad-copter or similar). Think of flying through a subway line with a drone that has a live camera that can be controlled remotely and the drone can also be controlled. The issue with anything off the shelf would be making sure you dont bump into any walls immobilizing the drone. Also getting the signal to the drone from the controller and also the live video signal back to the drone. The assumption is you would be some distance away (exact number not know but could be anywhere from a half mile to a couple miles or more) so the granite or other rock will make getting the signal an issue.
Any thoughts on possibilities?
Replies
I see you posted a few days ago, and no one has replied, so I though I would post some ideas :)
First of all, I can't imagine any kind of signal to penetrate the caves. But here are some ideas...
I think the best solution is to have several drones, each one to comunicate with each other and pass information "through it", through it's receiver/transmitter, so basically each drone is a "node" in a network. And have each one comunicate through multiple frequencies. When there is a corner in the cave, a 90 degree turn (or anything to block the signal), then land the drone and have the drone act as a "pass through" communication for the next drone. For obscacle avoidance, I think the best way is to surround it with IR sensors. Why IR? because they are very small sensors, and you don't need sensors for long distance, 2-3 meters range is more than enough...
As for the range/distance, that is a problem because the drone won't me able to fly at full speed through the cave, and most of the time will be hovering, so battery will drain fast...
But instead of quadcopter, what about a blimp? (or something semi, a mixture of quad, and blimp?)
If I were you, I would investigate to make a mixture of 3 in one (a rover, and blimp, and a quadcopter) I would have 4 baloons in the shape of wheels, filled with helium, then have 4 small motors with propellers on the sides of each (inner sides because then when it bumps into walls it will bump into the baloons). And also have the ballons on small gear motors, so they rotate the baloons like the wheels on a car, and have some ridges on the baloons so they have something to grip on. Now you can mix all when moving... so you cam move on the gound, and air :) this way you extend battery life to double or even triple the time you get from just a quadcopter. The only problem with this is areas/corridors with high winds, this might be a problem with quads also, especially if you design it for mainly hover power. For example if the drone hovers at 50% throttle, then it can deal with high winds because it has another 50% extra to go agaist the wind, but if the drone hovers at 90% throttle, then it cannot deal with winds because it has only 10% throttle extra reserved for winds...
The more gear you put on it, the heavier is gets, and the quicker the battery will discharge. That's why I think a blimp will be best, or anything that hovers at very low power...
Anyways.... just some ideas... very nice project by the way :) I wish I had unlimited $$ so that I could quit my job and work on stuff like this, because I have waaaayyy too many ideas. I have the knowledge, skills, pacience, excitement and drive for it, but don't have time and $$