Builder/Pilot Wanted for Giant Scale Plane for Aerial Photography

[Haoyang Wang]

At Compound Eye (compoundeye.com), we are doing real-time 3D reconstruction using multiple cameras. For one of our next aerial photography projects, we need to build such a prototype: a fixed-wing RC plane carrying our camera system, with a pair of cameras mounted at least 10 feet apart on a rigid frame.

This RC plane will then take some flights over targets placed on the ground, while capturing video images for later analysis.

The build project will probably start this summer. We'd like to get it in the air soon (in a month after the project starts?).

It can be a 3-meter ARF modified to carry our cameras at each wingtips. https://sigmfg.com/collections/sig-arfs-almost-ready-to-fly/products/sig-rascal-110egarf
It can be a giant foam wing, if such a thing exists.
It can be a used plane repurposed for this project.

An electric glider seems to be an attractive idea, especially given that it's easier to find gliders with such large wingspans.
. WIll the wings be rigid enough to maintain the fixed relative positions between the two cameras at the tips?
. Will there be enough space inside the fuselage for our microcomputer, etc.?
Currently I'd prefer a slow flyer with a large wing area, but as a friend pointed out to me: Some gliders can carry a turbine engine inside the fuselage. Replace the turbine with a motor in the nose, and there's all the space for my stuff... Overkill, but tempting.

Anyway, as a RC plane of this size is outside of my experience, we need contract it out for both building and flying. Please contact me for further details. Thank you.

 

[jure]

if you need a mechanically rigid wing , which will hold cameras at the wing tips with minimal flexing, I would think about a biplane .
Look at the wings of a biplane as an I beam structure or even a box...
how heavy are the cameras , BTW ?

 

[gp49]

@Haoyang Wang There is a 3.5m glider currently for sale in Washington, already setup for aerotow OR electric. It might be the ticket, depending on your payload weight and flying field size

K8B 3500mm Sailplane ARF 137.8" , Aerotow & Electric. W/ Servos and Spoilers - RC Groups

For Sale K8B 3500mm Sailplane ARF 137.8" , Aerotow & Electric. W/ Servos and Spoilers RC Sailplanes (FS/W)

www.rcgroups.com

 

[Wayne]

How rigid do the cameras need to be to one another? Wing tips always have some movement in them from load conditions on the plane. Looks like the cameras are rather small, but not sure about the rest of the gear.

Something like that SIG Rascal that has a strut wing might be the better option for you as that will help keep the cameras rigid and have a nice large fuselage for the gear.

Yes, large scale gliders can have rather massive fuselages, you could carry water melons in some of them. But those high aspect long wings may have too much movement for you.

 

[Red]

A couple questions if I may, as I do this for a living.

Please define rigid. Zero movement is not possible, so what is tolerable?
You say 10 feet apart, but then mention a 3M aircraft which is less. What is the absolute?
How much does the entire payload weigh?
How big are the cameras?
What are the power requirements?
Is there any telemetry requirements? If so what freq's and power?
Autonomous or all manual?
How long of a flight time are you targeting?
Will this be an ongoing test mule?

I may be interested if the timeline and requirements make sense. You should also be looking for someone who is FAA Part 107 legal.

Cheers
Red

 

[Wayne]

Red would be an excellent choice for this mission. Excellent builder and pilot and lots of experience doing mission flights.

 

[Hawaii Sloper]

A couple questions if I may, as I do this for a living.

Please define rigid. Zero movement is not possible, so what is tolerable?
You say 10 feet apart, but then mention a 3M aircraft which is less. What is the absolute?
How much does the entire payload weigh?
How big are the cameras?
What are the power requirements?
Is there any telemetry requirements? If so what freq's and power?
Autonomous or all manual?
How long of a flight time are you targeting?
Will this be an ongoing test mule?

I may be interested if the timeline and requirements make sense. You should also be looking for someone who is FAA Part 107 legal.

Cheers
Red

This reply sounds like AI. I'd be really careful of something named Alien_Tech. They could be here to scout our planet for harvesting or possibly terraforming....
Just a thought.....

 

[Haoyang Wang]

Thank you for the replies. You have helped me clear up the ideas.

The specs are not yet set in stone. Rather, it's the compromise from a set of conflicting wishes. For example, the client originally asked for "10 - 20 ft" between the cameras, while also preferring to have some results right away rather than waiting for us to build a half-scale plane.

This is a one-off prototype for the initial assessment of our camera system in the air. If it goes well, the real things will follow.

About the rigidity tolerance: We can deduce the relative positions between the 2 cameras in flight from the images captured, if the position stays the same during the captured sequence. Not quite so if the wings move from one second to the next. One of the project goals is to figure out how precise we can get.

At the planned target distance, the orientation between the cameras plays a more important role than the displacement. For example, 0.5 degree results in much changes, while a couple cm's up and down doesn't make much difference. If we end up having to model the camera movement mathematically, it would be simpler if the movement is in only one axis. (That is, if the wings flap and twist at the same time, we are hosed.)

So, as Wayne said, struts will be great. Ample carbon fiber reinforcement won't hurt. One-piece wings will simplify the rigidity, if we have a way for transportation.

So those large gliders are ballasted with watermelons?

Here are pictures of our current system https://www.compoundeye.com/vidas-devkit The computer that plans to go in the air will be about half of the size.
The camera units are small, at 50 g each? The computer and the battery may add up much more, but all should be under 1 kg. The video segment (and the flight time) will be less than 10 minutes each.

It has a phone-grade IMU (accelerometers and gyroscopes) and GPS as part of data collection, but the plane is to be flown manually. We may need a separate FPV camera to keep the targets in view.

 

[Doc J]

Thank you for the replies. You have helped me clear up the ideas.

The specs are not yet set in stone. Rather, it's the compromise from a set of conflicting wishes. For example, the client originally asked for "10 - 20 ft" between the cameras, while also preferring to have some results right away rather than waiting for us to build a half-scale plane.

This is a one-off prototype for the initial assessment of our camera system in the air. If it goes well, the real things will follow.

About the rigidity tolerance: We can deduce the relative positions between the 2 cameras in flight from the images captured, if the position stays the same during the captured sequence. Not quite so if the wings move from one second to the next. One of the project goals is to figure out how precise we can get.

At the planned target distance, the orientation between the cameras plays a more important role than the displacement. For example, 0.5 degree results in much changes, while a couple cm's up and down doesn't make much difference. If we end up having to model the camera movement mathematically, it would be simpler if the movement is in only one axis. (That is, if the wings flap and twist at the same time, we are hosed.)

So, as Wayne said, struts will be great. Ample carbon fiber reinforcement won't hurt. One-piece wings will simplify the rigidity, if we have a way for transportation.

So those large gliders are ballasted with watermelons?

Here are pictures of our current system https://www.compoundeye.com/vidas-devkit The computer that plans to go in the air will be about half of the size.
The camera units are small, at 50 g each? The computer and the battery may add up much more, but all should be under 1 kg. The video segment (and the flight time) will be less than 10 minutes each.

It has a phone-grade IMU (accelerometers and gyroscopes) and GPS as part of data collection, but the plane is to be flown manually. We may need a separate FPV camera to keep the targets in view.

I have done projects like this, or very similar several times, with some success, but alas, the logistics...

Red would be the man to do it if he can fit it in, and with his experience he can design a UAV to do the job very well.

Cheers,

Doc

 

[SailHigh]

Hi Haoyang,
Should you be interested in the smaller scale to check out your proof of concept first, I have a Senior Telemaster kit that could be very suitable. Senior Telemasters are renowned for their load carrying capabilities, steadiness in flight and robust structure. I was saving this as future tow plane. I am sure you can build this one yourself. Should you be interested, you can come over and check it out or I can bring it to Coyote someday. I'm slowly working on my part 107 to support the UAV group at Ames in the future, but that could be a while.

Sean

 

[jure]

see how rigid the wings of a biplane may be:

 

[keithskye]

At Compound Eye (compoundeye.com), we are doing real-time 3D reconstruction using multiple cameras. For one of our next aerial photography projects, we need to build such a prototype: a fixed-wing RC plane carrying our camera system, with a pair of cameras mounted at least 10 feet apart on a rigid frame.

This RC plane will then take some flights over targets placed on the ground, while capturing video images for later analysis.

The build project will probably start this summer. We'd like to get it in the air soon (in a month after the project starts?).

It can be a 3-meter ARF modified to carry our cameras at each wingtips. https://sigmfg.com/collections/sig-arfs-almost-ready-to-fly/products/sig-rascal-110egarf
It can be a giant foam wing, if such a thing exists.
It can be a used plane repurposed for this project.

An electric glider seems to be an attractive idea, especially given that it's easier to find gliders with such large wingspans.
. WIll the wings be rigid enough to maintain the fixed relative positions between the two cameras at the tips?
. Will there be enough space inside the fuselage for our microcomputer, etc.?
Currently I'd prefer a slow flyer with a large wing area, but as a friend pointed out to me: Some gliders can carry a turbine engine inside the fuselage. Replace the turbine with a motor in the nose, and there's all the space for my stuff... Overkill, but tempting.

Anyway, as a RC plane of this size is outside of my experience, we need contract it out for both building and flying. Please contact me for further details. Thank you.

 

[keithskye]

I have considerable experience with building and flying large radio controlled photo/video platforms such as you describe. Please contact me at your convenience.

Keith McLellan
jetjockeykeith@icloud.com
+1-928-706-8067
LinkedIn: https://www.linkedin.com/in/rovkeith