Advanced long-range helicopter

[Hulagutten]

Hi,

I am a total newbee to RC Helicopters, but I was wondering if the following would be possible, and what the main problems would be:

I would like to create a helicopter that I can control over large distances (like 5 kilometres/3 miles). This would require a camera on the helicopter and some kind of a link that would allow me to see the real-time pictures, and control the helicopter. As I am a computer programmer, I have though about the current solution so far:

Place a mobile phone with a good quality camera on the helicopter and connect to it via 3g (UMTS) which allows for video conferencing.

My specific questions are:
1. What size/type of helicopter would I need to lift the mobilephone, with a couple of additional components to connect the mobile phone to the helicopter? In order to fly 5 kilometres (and back) it would need to have space for a lot of fuel.

2. Roughly how fast could this type of helicopter fly?

3. Would the shaking of the helicopter make me unable to make sence of the video?

4. How much money would the helicopter itself cost?


Regards,

David

[kgfly]

David,

What you are describing is more of an RPV (Remotely Piloted Vehicle) than an R/C model. The distinction is very important in most countries since the laws governing RPVs are much more rigorous than those for models. R/C models do not (in most countries) require registration, licensing, documented maintenance, safety inspections etc. RPVs are usually strictly controlled by the aviation authorities and treated similarly to light aircraft and sometimes with even more rigorous safety controls.

So, you had better find out some more about the legal situation in your location before going too far down this track.

In your requirements you don't state the loiter time at the target location. Just flying 5kms out and back is one thing, doing something while there is another.

Model helicopters can fly at 50km/h or more, so a typical flight envelop might be: Launch - 1min, 5km trip - 8min, loiter - 5min, 5km return - 8min, recover/land - 1m. This gives an estimate of 23m flight duration. I would imagine you would need to look for a solution with a nominal 30min flight duration.

Providing a live video link of a good enough quality to remotely pilot a helicopter over a distance of >5km is likely to be beyond affordable. Your idea of using 3G cellphone technology is clever and perhaps it will work. If you are totally reliant on the video link for safe flying then I doubt 3G will be adequate.

Technically there are a variety of possible solutions. For around USD$10k-$15k you can buy a fully setup machine from Carvec ( http://www.carvecsystem.co.uk/index.htm ). You would have to add your video gear and I am not sure of the range/duration requirements can be met, but otherwise it will do most of what you need. In particular it is capable of GPS-guided autonomous flight and position hold so you would not be relying on the video link as a piloting aid.

VIbration is indeed a major issue for heli-based aerial photography (AP) and for best results a lot of fine tuning of the heli is needed to eliminate vibration. Electric helis are inherently smoother (no reciprocating engine) and so are often prefered for AP work.

Fascinating challenge to ponder

[MLaBoyteaux]

What you're describing sounds like something you'd find at NRI.

The cost? Probably in the $50K range for full autonamy.

Another one here http://www.rotomotion.com/prd_UAV_SR200.html

[Hulagutten]

Thanks kgfly. This really helped a lot! I will have to research the legal aspects, but as this is the boring part, I will do it later. For now I will see what Carvec has to deliver. I will try getting them to answer in this forum.

Thanks,

David

[kgfly]

Another point to note is that standard R/C radios cannot give reliable safe operation at a 5km range.

Some might achieve that range, particularly with true line-of-sight operation. However, unless you were operating in a remote, unpopulated area the risk of injuring someone would be far too high.

So you are back to RPV/UAV solutions like those used by the military and for example, oil companies. As you can see from the examples, prices are in the tens of thousands.

The military have spectrum they can use for long-range live video but for private/commercial use I think you might have to settle for on-board recording. You mentioned the use of live-video for flight control but with a UAV solution that may not be necessary, you simply program the mission profile and send it off.

[Hulagutten]

My best solution so far is to use the solution you suggested from Carvec, which can keep the helicopter steady if the communication with the "pilot" is lost, and use UMTS to communicate between the pilot and the helicopter. The reason why I don't want to simply record the video is that it gives a lot more possibilities if one can get real-time video. I guess one has to be creative with regards to the quality of the real-time video. Different solutions could be:
- Creating some kind of a "tunnel vision" where the pictures are the most clear in the center of the picture (the direction you are flying)
- To send one high-resolution picture every 5th or 10th second and low quality video in between. This solution would require the operator to sit in front of a computer with two screens for the two different picture qualities.

This solution should be a lot cheaper than the $50k solution from NRI.

[kgfly]

I don't know what the cellphone base station antenna radiation patterns look like, but I would bet they don't waste too much energy above the plane of the antenna. That might be a problem if you are going to rely on cellphone technology as a critical part of your flight control solution.

I will be very suprised if you get a license to operate an RPV/UAV at that sort of range over inhabited areas, the risk is just way too high.

[Garry S]

You might find this of interest - this guy makes a habit of flying long distances, relying on the downlink video picture. Referred to as FPV.

http://www.rcgroups.com/forums/showthread.php?t=595508