Robotic Airship, some ideas :)
2008-09-03 09:32
So i was looking at some flying robot designs, just out of curiosity. I ruled out helicopters and planes: they require too much precision in crafting and are too complex.. But alternatively an airship could probably be built :)
I've read on wikipedia that a square meter of helium can lift about 1 kg. A square meter means a big balloon, but a Kg is plenty of weight for electonics!
If you use light components, you can probably stay under 0,5 Kg or even less.
For example, some very light battery like this one at 1.1 Ah (only 22 grams!!) or this one at 2Ah, 36 grams.
The airship would probably be too light to effectively fly outdoor, but otherwise it would be nice to have a GPS module and a long-range radio link (this rates at 1,5 Km, not bad), and let it fly :P
There are micro servo that weights 8 grams, the GM10 motors wheight 5 grams.
For the balloon, one of the cheapest way would be to use a condom :P They're strong and light and cheap, the can be inflated to a cilinder that, with some inprecise calculation i did, could host about 0,1 square meter of gas. One could use two or three and have planty of lifting power :)
So the question is: am i completely crazy ?:P
No really, do you think this design could ever work? Of course the best would be to have something that can be controller outdoor, but i think it would be too much..
sure
There are several radio controlled helium ballon ships on the market already, so your plan is definitly doable. Here's an example.
What du you plan to use the servo for?
/ vzz-clck-"Maneuver"
they would be used to rotate
i looked around that site..
i looked around that site.. cool, they have nice stuff :)
The only thing: i could find a "blimp" for outdoor use.. they're all for indoor.. Maybe that size is not enought to substain open wind ? Should it be made bigger ?
Due to the shape, they are
Cool!
I think this would be a really good idea,
and if you did it, i would like to see. It probably would work,
if you try really hard. I hope you can do it!
you could also use a
Pretty cool idea. but maybe expensive
A cubic meter is 35.3 cubic feet. I found a party supply site here that sells helium in a small 14.9 cubic foot tank, for $40, so you might need more than 2 if shooting for 1 kg lift capacity. I read that a welding supply would be cheaper (and better quality) to get the helium, but you have the start-up cost of buying a $50-$75 regulator valve.
I've thought about the idea too, and considered dangerous (Hydrogen, 4 times the lifting power!) and hot air (huge envelope needed, plus some danger generating the flame).
i have a tank of helium in
i have a tank of helium in my workshop. Empty at the moment, but I can recommend this for anyone, it is worth every penny! Making stuff fly & hover in mid air is awesome! I have only made remote controlled blimps though, but that is very very much fun too! (Use inside only, little wind, puff..)
I think I will have to refill soon :) I hope you make the project Nicola, would be ace to see!
Be aware that ordinary balloons loose the gas very fast (nothing worth the next day-fast) - it seams to just vanish through the material somehow. The sort of blank foil-inside-kind of plastic that you get typical helium balloons in makes it stay much longer, but you will still need refill.
Also, when planing; You should know that these things do not stay in mid air. They follow the air around, even in the most still of rooms, they move around, so you will have to adjust in 6 directions constantly! ..hmm .. it may actually be quite hard.. because you will not know if you are traveling fast, up, down, or still etc. Hmm.. 6 SRF05's or 2 with some serious tilt & pan will be needed!
altimeter
I think a simple 3-axis
I think a simple 3-axis accelerometer would actually be perfect for this task. I don't yet fully understand when you need to supplement accelerometers with gyros -- maybe you'd need a combination of a 3-axis accelerometer and 3 gyros? Either way, it'd still probably be cheaper than 6 SRF05's :) This actually sounds like an interesting project -- building a blimp that can keep itself locked in one point in space even when wind blows, using fans pointed in all directions. What for? I don't know. Surveillance maybe -- I just like the challenge itself. I'll come up with an excuse for building it once it works :)
Dan
Why suppliment?
From my experience, the Gyros are very accurate but desperately slow to react. The Accelerometers show change much more quickly, but when you integrate acceleration to get speed, there's a notable drift. Someone might have a better technical explaination, but I used them in my balancing robot to calibrate each other.
Surely the SRF05s have a very limited range for this type of thing?
When to use what..
Gyros also drift etc - but this comment is is only about when to use what. If you want to see that "you are being moved", use the accel-thing. If you want to see "where you are", use the gyro.
Example: Make a self-balancing plane. If you use accel-thingeys, when the plane starts it thinks it is pointing downwards due to the acceleration. So use a Gyro for that.
Example: Make a robot that jumps and unfolds itself once it is at the peak of the free air-time. If you use a gyro you can only detect tilt, so use a accellerator.. acceler.. erh-thingey for that.
:)
just to precise, the gyro
Oh yes.. erh.. well. some
Both or either
Well, with the correct mechnical arrangement, rate gyros and acelerometers can give complimentary information. I thought TCG was asking why one would use both together (eg in applications such as a co-axial wheeled robot)...
Uhm it's going to grow less
Uhm it's going to grow less and less cheap each line i read :)
Yes, the helium escape becouse its atoms are very small and can pass between the plastic fabric.. I've read it on wikipedia :) I don't know how condoms rate at this.. but if i have to guess, given what they're for, i'd say good :)
Stabilizing would be a problem.. You need extra motors, and with extra motors come extra weight, so bigger balloon etc etc. And IMU sensors are expensive as hell. So i don't think i'll be building it anytime soon..
It's a pity.. I was already imagining to fly it to my friends houses via GPS and have live video of them being scared as hell, and then shooting them with the powerful onboard lasers.. Well, something like that :)
PS That pressure sensor looks interesting, it would be a must have for a serious blimp
I am quite offended by this idea...
CONDOMS?!?!?... CONDOMS?!?!?!?
I support abstinence-only robot education!
Protection
I dunno if condoms would work. Helium atoms are very small. Do you have custom condoms
for very small things? Ballon material is actually full of holes about the size of helium atoms. Dunno wha the deal is with the metallic stuff. I guess it has fewer or smaller holes or something.Three or four separate
Three or four separate motors pointing in different directionswith propellers on them would weight the same and be much more versatile than one motor with a servo.
I didn't really check the site I linked to, I just googled it. But there are several indoor helium blimps available online, I'm sure.
/ vzz-clck-"Maneuver"
Combo!
I would go for a combo. A helium ballon to take most of the weight and three upward facing motors on servos. Twisting the motors would allow somplete freedom in 3D. Maneuverability, speed AND a smaller balloon. All good.
Incidentally, there's no way a metre squared of any gas lifts anything. That would be a metre cubed...
lol sorry, i meant cubed
Whoa, BOA...
Indeed
Big Smile
You've brought back memories from 20 years ago.
I'm amused by this thread, and will follow it. From personal experience, I can tell you that a condom will hold a large volumn of helium. Enough to lift sereral ounces at least. In our "experiments", we taped pennies to them for ballast and balance, so they'd stay somewhat level, and crepe paper steamers for visual effect. (With creative graphics drawn with permanent markers).
We were flying our "Trojan Blimps" inside a factory production room (on the mid-night shift) which had an accoustical tile ceiling, about 25 feet high. They were subject to the slightest air movement. We could sort of "control" thier flight with blasts from compressed air hoses from floor level.
I don't really know how long they would hold the heluim before it leaked out, because the longest that we had one last was just a couple of hours. Eventually they'd bump into something and go "POP". Either that, or get shot down by an opponent, using a rubber band and paper clip. Fish hooks were also used sometimes.
We'd have 6, 2 man teams, with 6 "Blimps" going at a time. It was great fun.
So, a condom WILL fly. But, trust me, it is NOT very durable.
I'm sure that management would have frowned on our hi-jinks, but as far as I know, they've never found out about it.
The closest that we came to getting caught was when Mark, AKA "Big Dick", got a treble fish hook stuck deep in his finger, and had to go to the Emergency Room to have it removed. That was the wildest, most fabricated safety incidence report that I've ever known of. "So how did you get this fish hook stuck in your finger?" "And why was it attached to a rubber band?"
Duane S
Wilson, North Carolina USA
lol, duane that was a very
Yeah, I agree. I wish that
Yeah, I agree. I wish that my current job was as much fun. We were able to do things like that because we had a lot of idle time, and needed the distraction to keep from going crazy.
During a midnight shift, we'd go from boring periods where 4 people could run the entire operation, to frantic periods where we needed 50 people, but didn't have them.
The best part was that our crew was able to set several production and quaility records while engaged in these kind of distractions, and upper management never had a clue about how we did it. And we were not telling. Our standard answer was "good teamwork".
Duane S
Wilson, North Carolina USA
Sometimes you read what your
Sometimes you read what your mind tells you, guess what I read here:
"I can tell you that a condom will hold a large volumn of helium."... "we taped pennies to them for ballast"
Well.. it was not the word pennies that I read :D
don't use condom...
in fact dont use anything that is elastice like balloon meteorologic ballon, ect. anything that is flexible is very bad for aerodynamics, use "aluminzed nylon" instead it's most time called Mylar but it's not. you can make your ballon by sealing it with an iron.
I've did a lot of research on that field and aluminized nylon is the best you can get.
rc balloon