Idea: Home brew uav

Started by Genken, September 17, 2012, 12:58:39 PM

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Genken

I've been toying with an idea in my head for while now, a model airplane controlled on 6 meters. Sure, max output of transmitter is low (1 watt, iirc), but you throw a video camera on a 70 cm transmitter sending you live feed, and you have an amazing force multiplier.

The biggest problem is weight, and flight time. It doesn't have to be fast, it just has to fly. Quiet is good.

Ideas and thoughts for discussion?

gil

Electric motor.. You can recharge it with solar panels. Why not use an off the shelf remote?

Gil.

WA4STO

Six meters has a HUGE following among the RC aircraft gang.

But, aside from the fact that it's more or less line of sight, and 1 watt is more than adequate for that, is there something in Part 97 that precludes you from running a kilowatt?  It's been a lotta years since I helped write the "FCC Rulebook" and I just can't remember, and few ever asked me about that particular niche in the rules.

I built a little robot (Parallax.com) that looks much more like a tank than a robot, probably about ten inches long, including the front grabber assembly.

I program it with a USB cable.  But the servos ... they're controlled by a big remote.  You know, one of the ten dollar ones that's made for folks with limited sight.  Those remotes (and most others) have always been infrared.  So to answer Gil's question about the use of remotes, they're ok for distances measured in feet, maybe yards at best.

I have no doubt whatsoever that the data you'd be coding and sending at 50 mHz has already been accomplished, and is probably online, ready to use.  But if you're ever going to be competing, or in an area that is shared with other RCers, one reason to DIY the coding of the signal yourself is to avoid somebody else's transmission which says, "GO left!" when you really, seriously needed to "GO UP - NOW!"  :(

The folks at Parallax came up with a really superior scheme, even if it was done with IR frequencies.  What they did was utilize a standard SONY protocol.  Most TV (or at least those that can be programmed for different remotes) can utilize the SONY standard protocol. 

I'm wondering why we couldn't do the very same thing, but with six meters.  The regs allow us to use some pretty fast transmission rates up there.  And the protocol allows us to design the control routines in such a way that NO other RC vehicles in town are gonna be doing the same thing.  And, of course, all the kiddies trying to bring your plane down with their 46000-per-town remotes are gonna fail.  Miserably. 

This really sounds like fun.

As for the ATV onboard, 430 mHz would be great.  Unless, you're in/around a fairly large city where other uses of 430 might be problematic.  Then, oh ya, there's the guy just down the street who is cranking 300 watts up to the amateur radio satellites on 432.  His uplink quickly becomes your downlink! :(

Bring on the drones!  We have met them, and they are US!  :)

gil

Well, I know close to nothing about aircraft models, but I am pretty sure the limit is 1W for remote control...

Gil.

WA4STO

Gil - I believe I know somewhat less than YOU do about r/c stuff!  :)

But, I looked around and found this:

"Going through 47 CFR Part 97 there are no set RC frequencies. Basically, you can use any frequency on which data transmissions are allowed and on the 6-meter band this means anywhere in the band from 50.100 MHz up to 54.000 MHz. The only restrictions are that the transmitter cannot put out more than 1 watt and that there must be a label affixed to the transmitter stating your name, address, and callsign. This per 47 CFR Part 97 Section 97.215.

The individual frequencies were adopted to provide fixed reference points to prevent (or at least minimize) interference among those amateur radio operators who use the 6-meter band for radio control. As such, the stated frequencies are nothing more than a "band plan" which, although a good idea, has no force of law."

Almost without exception, people are saying that the use of six meters is a terrible idea.  They go on about this and that, and about how the zillions of channels on 2.4 gHz are in vogue now and ... well ... I keep coming back to the whole notion of line of sight.   O.T.O.H. do we want to be controlling r/c aircraft beyond what we can see?  Oh yah!  the ATV gear to the rescue!


gil


Genken

Well, I was thinking of trying to find some type of lightweight battery, maybe laptop? I was also thinking small solar cells across the top of the wing as well, so the plane would probably resemble a cargo aircraft with the wings at the top of the fuselage.

As far as 6 meters, I don't recall it saying anything about antenna location limits, which with a 70 cm antenna up there as well, can help with reception of the video.

And my original thought on this is for use at a retreat, or if you could get enough speed out of it, from the passenger seat of a bugout vehicle to scout ahead for any potential issues. A remote or even semi-remote retreat would have the most benefit. I've seen first hand how the small army uav's like the raven and puma can change your situational awareness from light of sight to multiple mile radius right after it's launched. And landing involves breaking apart.

Sorry about poor quality typing. Doing this on my phone and about to fall asleep

Paul

It's a nice idea but not as simple/easy as you might think.  Learning to fly the thing to start with is quite a chore, not everyone can.  Then there's the electronics side of it, not as hard or complicated, but also not a huge range to it either.  If you can't see that plane it's very unlikely that you are going to be able to control it.  For a real UAV you are not talking hobby stuff anymore, it is expensive like you wouldn't believe.  It also requires you to learn to fly, not by observation, but by the 'seat of the pants'.  That is also not easy by any means.
- Paul

(I love building those R/C plane but can't fly them.  I've got a pilots license in my pocket, it is NOT the same thing at all.)

Genken

Paul,

I understand where you're coming from. And I agree. I've seen our company level UAV guys (The Raven and Puma UAV's) fly those things, not easy. But, that is why you have the video feed. If you angle a camera down about 30 degrees, give or take, you can see where you're going and what you're trying to observe. Mount it on something big and stable, and it shouldn't be too bad to control. The Raven is a small UAV, about a a foot and a half to 2 feet long IIRC, and the Puma is about 5 foot long. Granted, I could be off a bit on size, it just gives you an idea. Seeing both of them fly, the Puma definitely have more stability. At a fixed site, you don't really need speed. Plus, even at 1 watt output, with enough elevation to clear any obstructions, you should have a decent range on 6 meters. Even a few thousand yards is better than nothing. Means you don't have to have as many people out and about patrolling an area as often. Or, the ability to scout for a patrol thats out. Locate them before they locate you.

gil

I agree with Paul. The cost and complexity can be enormous. To fly the plane, you need to see the horizon too.. You would probably crash a few before getting the hang of it.. Think really carefully about this before spending your money.. If you go ahead, get a regular small model and fly that first.. There are small electric planes you can easily attach a wireless camera to.. Range is limited, but it might give you an idea.. You don't have to build something from scratch. You'd have to buy an existing plane design anyway. Designing an aircraft, even a model, requires a vast knowledge in aerodynamics and aeronautical engineering. Anyway, I'm not saying it's impossible, but a project like that would take over your life and your bank account.

Gil.


gil

That's a funny video right there!

raybiker73

#12
I've been flying electric R/C for quite a while, and airborne photo/video isn't really too hard. You can take about any plane that will handle a little weight, graft on a small camera (or an old phone you don't care too much about), and add a servo to work the shutter. Mountain Models used to make a plane kit called the Magpie, that you could get with a dedicated AP mount. I've had the kit for a couple years but haven't yet finished it, maybe next spring I'll use it and my old iPhone 4, which should work great.

This pic was my first AP experimental shot, from 2005. It's the back end of my property near the tree line. I used an old ParkZone Piper Cub with an even older 1 megapixel camera taped to the bottom, with a servo to trip the shutter. With that ancient old camera and a cheap RTF quiet-flyer, I had to cut the power to the plane before tripping the shutter or the photos would be shaky from the engine vibration. Using a newer foamie plane with a brushless motor and a modern camera, a person could get some amazing photo and video without a huge investment in time or money. Heck, cameras are so light now compared to seven years ago, you could mount a second one front-facing and fly by monitor if you had enough bird to carry it.

EDIT: almost forgot, if you're using an iPhone or an Android phone, you could fire up the "Face Time" or equivalent app and get real-time video on a phone at your base. Just a thought.

White Tiger

#13
I'm pretty sure I saw a lot of the still photography stuff on single stage hobby rockets a few years back (OK...probably more like 10 years ago).

It would surprise me if this technology wasn't already "off the shelf" - if you don't want to utilize existing stuff - why not reverse engineer it and build something similar?

Here's a HubPages blogpost about a model called the "Eagle Eye" w/camera system by Art-Tech. It's on a more stable RC helocopter platform.

R.C. Aerial Photography, Affordable For All

Here's a camera specifically designed for aerial photography (stills & short videos). The difference is, this one doesn't have a monitor for what it's filming "live"...just stores it in memory and you play it back later.

Smallest 18G FPV Micro Video Camera for RC Airplane, RC Helicopter, RC Car w/ FREE 2GB Memory Card

I think this is a fascinating topic - although I'm waaay behind the folks who say they don't know much about it!

Hopefully this helps somewhat - certainly seems entirely feasible - if you know what you're doing!

I'll be following this thread eagerly!

If you're looking for me, you're probably looking in the wrong place.

explo72

there is a site devoted to home brew UAV's, has some pretty cool stuff including several off the shelf models.

http://www.diydrones.com/