Group of Underwater Gliders  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
  Printable Version
       



All Forums >> RC Boats >> RC Submarines >> Group of Underwater Gliders Page: [1]

Login
Message << Older Topic   Newer Topic >>
Group of Underwater Gliders - 11/17/2003 12:33:16 AM   
micromark03


 

Posts: 5
Joined: 11/16/2003
From: Manchester, UNITED KINGDOM
Status: offline 		Hiya,

Im designing a group of underwater gliders, which are to be have the ability of being controlled by RC.
We've ruled out RF comms, due to range and power, so are thinking B Field comms.
Was wondering if anyone that had any experience could offer any advice as I'm a complete novice to underwater comms. (Useful links/books etc or just general pointers!)

Also if each glider were to have its own Joystick, how do you enable each Joystick to only communicate with its specific glider? I know it sounds like a simple question, but am quite lost on it!

Thanx very much, any help will be gr8,

Mark
       Post #: 1

RE: Group of Underwater Gliders - 11/23/2003 9:32:30 PM   
Cactus.



Posts: 6138
Joined: 12/19/2001
From: CamborneCornwall, UNITED KINGDOM
Status: offline
quote:

I know it sounds like a simple question


does it???? i'm lost.. control of each glider...? glider??

different frequencys control each glider. whats b field comms?

_____________________________

My half dead website www.philsrcworld.fsnet.co.uk new site coming soon.
Redruth & District model flying club www.rcflye

(in reply to micromark03)
       Post #: 2

RE: Group of Underwater Gliders - 11/26/2003 11:06:46 AM   
micromark03


 

Posts: 5
Joined: 11/16/2003
From: Manchester, UNITED KINGDOM
Status: offline 		Sorry if i confused you!

A glider is a form of sub, but instead of being propelled forward it glides, by rising and falling in the water.

My question was, if you had numerous subs all being controlled by remote, how does each sub know which remote to communicate with????

And B field comms, is like impressing a data signal on a magnetic field!!!

Any clearer??

(in reply to micromark03)
       Post #: 3

RE: Group of Underwater Gliders - 11/26/2003 11:37:44 AM   
Cactus.



Posts: 6138
Joined: 12/19/2001
From: CamborneCornwall, UNITED KINGDOM
Status: offline 		the water has enough flow to do this? like slope soaring underwater. or.. as it falls it uses wings to move it's self forwards, ???
i don't even understand how you can use a magnetic field to control something...

more info please, not that i can help anymore, but i'd love to see what your working on

_____________________________

My half dead website www.philsrcworld.fsnet.co.uk new site coming soon.
Redruth & District model flying club www.rcflye

(in reply to micromark03)
       Post #: 4

RE: Group of Underwater Gliders - 11/28/2003 8:17:07 AM   
discoboy


 

Posts: 28
Joined: 10/20/2003
From: Norwich, UNITED KINGDOM
Status: offline 		Re. controll, the radio controls that are normally used operate on seperate radio frquencies. You get a matched pair of crystals for the transmiter and receiver.

(in reply to Cactus.)
       Post #: 5

RE: Group of Underwater Gliders - 11/29/2003 9:06:18 PM   
discoboy


 

Posts: 28
Joined: 10/20/2003
From: Norwich, UNITED KINGDOM
Status: offline 		By the way,

What size are these gliders?
What sort of range do you need?
Why are you trying them?

Just wondering...

(in reply to discoboy)
       Post #: 6

RE: Group of Underwater Gliders - 11/30/2003 6:57:30 AM   
BrittB



Posts: 62
Joined: 3/26/2003
From: Keizer, OR, USA
Status: offline 		I've been doing R/C subs for a long time and even I am not sure what your talking about. What kind of water rises and falls?

_____________________________

Britt Boyette
Break Like the Wind Racing

(in reply to discoboy)
       Post #: 7

RE: Group of Underwater Gliders - 11/30/2003 4:24:51 PM   
Cactus.



Posts: 6138
Joined: 12/19/2001
From: CamborneCornwall, UNITED KINGDOM
Status: offline 		i think he means... as you fall you use movable wings to push the "glider" forwards. you have to be moving either up or down to move. not sure why this is advantageous way of control, motors are more expensive and heavy, but you have better control

_____________________________

My half dead website www.philsrcworld.fsnet.co.uk new site coming soon.
Redruth & District model flying club www.rcflye

(in reply to BrittB)
       Post #: 8

RE: Group of Underwater Gliders - 12/1/2003 4:50:34 AM   
LtDoc


 

Posts: 1750
Joined: 11/29/2003
From: McAlester, OK, USA
Status: offline 		FWIW

Underwater 'gliders' isn't a new idea, it's been around for quite a while. The major problem seems to be having enough 'depth' for the system to work, and having enough ballast control.
It's just like a glider soaring in still air. Point the glider down and you get forward motion and loose altitude. If you could make the glider lighter than air, then tilted it up, you would still get forward motion and an increase in altitude. The same principal works in water instead of air, ~IF~ you have a lot of depth to work with. Lots of ups-n-downs to get the forward motion.

As for modulating a magnetic field, while it's certainly possible, it's going to have even a shorter range than using radio frequencies under water. A 'better' solution would be a lower radio frequency (as in VLF), but since there aren't any allocated for RC use, and since the Navy tends to get mad if you mess with 'their' frequencies, I think it's a waste of time.
But wouldn't it be fun?
- LtDoc

(in reply to Cactus.)
       Post #: 9

RE: Group of Underwater Gliders - 12/1/2003 6:17:22 PM   
Cactus.



Posts: 6138
Joined: 12/19/2001
From: CamborneCornwall, UNITED KINGDOM
Status: offline 		could you use sound waves? kinda like shouting at it might get a few whales trying to mate with it tho

_____________________________

My half dead website www.philsrcworld.fsnet.co.uk new site coming soon.
Redruth & District model flying club www.rcflye

(in reply to LtDoc)
       Post #: 10

RE: Group of Underwater Gliders - 12/1/2003 6:26:24 PM   
tiggerinmk



Posts: 1527
Joined: 12/30/2002
From: Milton Keynes, UNITED KINGDOM
Status: offline 		Sounds like this could get silly real quick.

I can just imagine someone standing in the deep end of a swimming pool wearing a snorkel and goggles controlling a glider with a radio wrapped in a waterproof bag...

_____________________________

If you can remain calm, while all around you is chaos...
then you probably haven't completely understood the seriousnes

(in reply to Cactus.)
       Post #: 11

RE: Group of Underwater Gliders - 12/1/2003 6:36:43 PM   
Cactus.



Posts: 6138
Joined: 12/19/2001
From: CamborneCornwall, UNITED KINGDOM
Status: offline 		or gurgling "turmbbbbbbbbbooo lebbbbffttb yooobbbbububuuuu bbbasbbbbbbbtburbbbbbb"

think sound waves could work tho...

_____________________________

My half dead website www.philsrcworld.fsnet.co.uk new site coming soon.
Redruth & District model flying club www.rcflye

(in reply to tiggerinmk)
       Post #: 12

RE: Group of Underwater Gliders - 12/1/2003 7:13:07 PM   
LtDoc


 

Posts: 1750
Joined: 11/29/2003
From: McAlester, OK, USA
Status: offline 		Could you use sound instead of RF? Sounds a lot like sonar, and yes you can. Control would be slower because of the difference in speed between RF and
sound in water. The bandwidth of 'channels' would also be narrower and the signal would also be more susceptible to interference from natural and man made noises. None of which can't be 'cured'. I'd be willing to bet that the Navy has done experiments like this. I'd also be willing to bet that getting your hands on the results of those experiments would be next to impossible! Or, stealing another idea from the Navy, how about using 'blue/green' lasers instead of RF??
Sound like sicence fiction? So was sending people into space just 40 years ago...
- LtDoc

(in reply to Cactus.)
       Post #: 13

RE: Group of Underwater Gliders - 12/2/2003 3:30:40 AM   
BrittB



Posts: 62
Joined: 3/26/2003
From: Keizer, OR, USA
Status: offline 		Someone still has to go for a deep swim after it's all done. If it's in a swimming pool you can use an off the shelf radio on 75mhz but if I wanted to play fetch, I would buy a dog or take up golf.

_____________________________

Britt Boyette
Break Like the Wind Racing

(in reply to LtDoc)
       Post #: 14

RE: Group of Underwater Gliders - 12/2/2003 10:30:32 AM   
micromark03


 

Posts: 5
Joined: 11/16/2003
From: Manchester, UNITED KINGDOM
Status: offline 		Ok! I seem to have caused a lot of confusion here!
So first of all Im sorry!!!

quote:

Underwater 'gliders' isn't a new idea, it's been around for quite a while.
It's just like a glider soaring in still air. Point the glider down and you get forward motion and loose altitude. If you could make the glider lighter than air, then tilted it up, you would still get forward motion and an increase in altitude. The same principal works in water instead of air.


So hopefully thats cleared up the "Glider" question! Thanks LtDoc.

The hull is going to be about 1 meter long and about a foot wide (plus the wings, and fin). We need them to work over approx a 15 meter range underwater (salt water). We not only have to communicate with them via remote control, but they also have to work autonomously and therefore need to be able to communicate with other gliders.

We cant use Radio frequency becaue we would have to use VLF and that would require a large antenna which we dont have space for, and we dont want a trailing wire.
And to make things worse were not allowed to use any form of acoustic communication!!!!!!

Were making these gliders as a Project which has set specifications, so we have to stick to the rules!!!

Thanks for all the ideas, keep them comming.

Mark

(in reply to BrittB)