UAV design/control questions

[spastic]

I'm working on a simple turn-key ARF "mule" for UAV experimentation and have some questions to work out the design parameters.

1) Can most UAV control software/hardware can handle V-tail (or inverted V-tail) mixing. Or is it much easier to stick with conventional controls (vert/hor stab and ailerons).

people with auto guidance control experience, what is your opinions on tail configuration?

2) for payload placement, is it very important to have it on the center of gravity? The vehicle would have a movable wing/tail section so the cg could be adjusted after payload changes.

3) A Pusher type power system keeps the front of the aircraft clean for video gear and instrumentation; is this a big plus? or not that big a deal?

4) what size payload (how big does it need to be) would 80% of the people doing this be? or is it too hard to nail down one size? we could do more than one size but it looks like a 6-7foot (~2meter) design would be first with a 1-2Kg payload. And what size payload volume would this need to be?

5) your feeling on electric power vs gas vs glow? (for this small one, E-power might be best)

I have model airplane design experience, including commercial ARF’s but no software or guidance electronics experience so this will be a learning experience in that regard.
This is in the very early stages, i will keep this thread going with progress.
Thanks for the help!
Gary

[CenTexFlyer]

Gary,

It might help if you decided what your intended application would be. If you are driving screws, a hammer wouldn't be a good fit as your only tool. Your application (and where it is to be used) would also help in determining what your payload requirements might be.

For example : If you look at just aerial photography. Folks have used just about every configuration airframe you can think of, but each is highly modified for the camera they intend to fly. Some of them fly well in the wind, some do not. Some are fairly small and easily launchable, others require a prepared takeoff/landing area.

So my recommendation would be to break it down a bit further before making your decision to commit $$$ and time to a commercial application. I'll be happy to give you my opinion on each of your questions though.....

1) Can most UAV control software/hardware can handle V-tail (or inverted V-tail) mixing. Or is it much easier to stick with conventional controls (vert/hor stab and ailerons).people with auto guidance control experience, what is your opinions on tail configuration?

It's more hardware related. As long as you get a control loop refresh rate of better than 1Hz you should be in good shape.

2) for payload placement, is it very important to have it on the center of gravity? The vehicle would have a movable wing/tail section so the cg could be adjusted after payload changes.

Center your payload makes flying the vehicle easier if you need to change it out to something lighter/heavier. If this is a commercial application, you are asking a "user" who may or may not have any flight experience to calculate a CG - which could be setting them up for failure and then them complaining that you make a bad product.

3) A Pusher type power system keeps the front of the aircraft clean for video gear and instrumentation; is this a big plus? or not that big a deal?

Again, a matter of what the application would be. True enough, the nose is all cleaned up, but what if you only need to shoot straight down? Doesn't really matter then.

4) what size payload (how big does it need to be) would 80% of the people doing this be? or is it too hard to nail down one size? we could do more than one size but it looks like a 6-7foot (~2meter) design would be first with a 1-2Kg payload. And what size payload volume would this need to be?

You don't need two meters to fly a 1-2kg load, and again only you can determine what your target market is. It would be hard for us to tell you what 80% of your market might need.

5) your feeling on electric power vs gas vs glow? (for this small one, E-power might be best)

Electric would likely be the easiest for your "user".

Gene

Gene

[macboffin]

Suggest you check out the great variety of suitable airframes, and in particular smaller UAVs, already on the market.They run into the hundreds!
For commercial success with such a product, yours would have to have some particular advantages, ie remarkable inherent stability, very low cost or high cost-effectiveness. Since the likely market for such aircraft, aimed at amateur experimenters, would probably only be at most a couple of hundred, it doesn't look like a commercially viable enterprise.
Sorry about that, but thats how it is! If you want to do some experimenting yourself, almost any of the larger "trainers" out there would do as an airframe ; the "Telemaster" for example.

[clolson]

Just to toss in my 2 cents ...

It is my observation that effective aircraft tend to be purpose built for a specific application. That makes it tough to come up with a single airframe that will have a wide ranging appeal in the UAV world.

For testing and development, a wide body trainer style aircraft with easy access to all the open area in the fuselage would be nice. Something on the larger size is nice for those that don't know their exact payload or application heading into the project. But the larger the aircraft, the more difficult it is logistically to transport, store, and operate.

As soon as you get into a specific purpose or specific application, people start looking hard at performance specifications, cruise speed, payload, endurance, range, launch and recovery options, robustness of the airframe, etc. That's where you quickly need to move to specific design choices and often end up with an airframe and launch/recovery procedures that are not beginner friendly.

Regards,

Curt.

[spastic]

Thanks for the info so far, keep it coming. :)

can someone elaborate v-tail control?
i have experience with many v-tails (rc gliders and hotliners) with rc but i'm not sure how typical auto guidance systems will handle the mix, is this standard? excuse me for the rooky like question :o does it complicate the programing? i really like the idea of a v-tail on this project but if it is more work for the programer i will not use one.

Looks like I need to be more specific to my objectives here, :o
I agree there are many commercial UAV's on the market, but that is not what this is aimed at, (“commercially available”, not to imply commercial applications). :)

Maybe I should start to list the objectives so far, this discussion is useful in fine tuning these objectives so it can suit you guys (possible customers!) ;)

This project is aimed at the university "contest" type and the "weekend uav warrior" which I think most of the people on this site fall into, yes or no?

Commercial success is not measured in the thousands of units for us, and I think the Telemaster is a great sport rc airplane and an ok uav that takes more work than is should to use as a UAV. Think of this as a better suited rc airplane, that looks like a proper uav.. I do realize that what is “proper” will depend on the application. But flexibility is a key factor here.

Through my research into this project it looks like most people in this segment are using off the shelf rc airplanes, Telemasters, Sig Rascals, .60 size Trainers for example. I know I can do better.

Things I think could be done to make an aircraft better out of the box:
1)Large lift capability, stability at max weight, payload limit that is clearly defined and safe (structure is designed for it).

2)Strong undercarriage ready for max takeoff weight. (Tricycle gear for sure)

3)Large volume payload area, very easy to access and modular.

4)Glue free assembly, again modular.

5)Small breakdown size so it fits back into the reinforced shipping box.

6)Inexpensive, this will be traditional built up balsa, ply, some fiberglass, and carbon. It will be competitive with the retail price of a Telemaster (when you look at the extra time and hardware modification saved)

7) pusher, pod-boom type airframe. making it simple, inexpensive and robust.

my idea for possible uses; (in no particular order)
1) university type contests like the the Outback uav challance (i've read the rules and this aircraft would be good to go) there are many contests each year like this.

2) rc camera platform

3) gps guidance and telemetry mule (for designing or "playing with" guidance systems)

any more?

thanks for the input, keep it comming.
Gary

[zlite]

A model-sized version of the classic twin-boom, pusher prop Pioneer UAV would be very welcome. As far as I know nothing like that is currently available.

[spastic]

A model-sized version of the classic twin-boom, pusher prop Pioneer UAV would be very welcome. As far as I know nothing like that is currently available.


very much the form it's taking :)