Re: Winch rigging + kite video

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Nautilabs/Baptiste LABAT

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Feb 20, 2017, 5:31:36 PM2/20/17
to Trevor Jack, hes...@control.ee.ethz.ch, robokite
Hi Trevor,
I forward to the group (I hope it works just like this)

++

2017-02-16 1:17 GMT+01:00 Trevor Jack <tre...@moretonbaykiting.com.au>:
Baptiste,

Fine to share email - I don't use google groups.  I tried but seemed to need to repost all that was already there?
 
I have no video from the launch sequence yesterday and only video that is too poor to be useful from centre launching large kite.  I may have shared this before?  It shows how a small single skin kite can be flown off just the centre bridles then released to the full bridle.  The LE bridle lines in the wing tips are slightly tensioned (B, C, D and Z all slack) in order to prevent the kite flogging too much.  It flies with dynamic stability - that is, it oscillates but does not crash, with no steering input.  Stability is better than with the full canopy inflated.  Perhaps the flapping wing tips damp the restoring steering input from the separated tow points.

Thanks very much for the video and the link and instructions for your tracking system.  I will look into those (with help from my son).  We don't want to reinvent something that has already been done - and if we can use or even improve it, we will share.

The video from Henrik Hesse looks very good, particularly with the sun so close to the kite - I'd like to know more about that!

We had a quite unsuccessful outing on the new proa last weekend.  No kiting.  Hopefully we will get out this weekend with a kite up - if we do, I will send video and a report.

Thanks again,

Trevor

On Thu, Feb 16, 2017 at 9:43 AM, Nautilabs/Baptiste LABAT <baptist...@nautilabs.com> wrote:
Hi Trevor,

Thanks a lot for sharing your progress! Have you got some video footage, or soon ;-), or at least a photo?

I wrote a machine kite tracking a few years back. I haven't tested it for a while, but the code should still work.
It is color based, and I tested it with several kites. I could give more advice if he wants to restart from scratch.

Here are some instructions to install/use it, but please ask if you have some troubles (and it will help to improve these instructions for others).

Here is a video demo in replay based on this raw video.
Here are a few videos I used to test.
https://www.youtube.com/watch?v=_C4rry7VkGg&list=UUa67hFWRqXyehBhyk3YfBnA&index=19
https://www.youtube.com/watch?v=fNMO3kAX0PE&index=11&list=UUa67hFWRqXyehBhyk3YfBnA
https://www.youtube.com/watch?v=jn9RrUCiWKM&list=UUa67hFWRqXyehBhyk3YfBnA&index=10

The last two videos are from High-Zenith-Power (youtube) a studient canadian project. I have tried to use their code but never succeed and had no more response from them.
This project is now hidden, but you can still access the code with this command
svn checkout http://zenith-wind-power.googlecode.com/svn/trunk

More recently, I saw some demo from Henrik Hesse from ETH Zurich as well. I made some searches and was able to find it
I add him in copy, may be he can share his code or give some advices?

Hope it will be clear enough for your son!

++
Baptiste
PS: can I share your email on the robokite mailing list ?

2017-02-15 23:17 GMT+01:00 Trevor Jack <tre...@moretonbaykiting.com.au>:
Hi Baptiste,

You had sent me a rigging schematic for launching/steering.  I modified that and tried it, with some success, with a 2 line bridled single skin kite yesterday.  

There are 2 "launch/retrieval" winches.  These are coupled and have brakes.  When coupled they function as a single winch.  When decoupled the line on the driven winch can be moved so as to rebalance the steering lines - this would be necessary due to uneven winding on the two winches (though it wasn't necessary yesterday).

My pilot, controlling the steering winch, quickly learnt how to steer with the winch so we released the kite from bridle length, where it flies without steering input, to about 15m quite successfully (our area was restricted so we couldn't release any higher).

​My son, who is doing research in machine vision/image recognition, asked me yesterday for some video of kties flying so that he could use it to investigate training a recognition model.  Do you have a library of such video?  

Regards
 
Trevor
0408 152 414
www.MoretonBayKiting.com.au



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Trevor
0408 152 414
www.MoretonBayKiting.com.au



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