T3 Season 2, The Model


Its T3 time again but first I have started tagging people that have entered T3 in the past on their member icons its a very small recognition for their valuable contributions which have driven APM forward faster than it might have without the competition. They have not only put their equipment on the line discovering new ways of doing things but countless hours as well.

Unsung heroes in the development of low cost autopilots for all.

So lets get into this round.

I waste far too much time on the most excellent GEFS there could be more 3D buildings laid on top of the Google Earth base layer. Lets change that.

The last T3 challenge "The Cube" bought some really outstanding results and the natural progression from this is automated flight around a building or natural point of interest and the creation of a 3D model perhaps in 123D catch of the subject. Last November Alan Sanchez showed us how. Improvements in the multirotor code that came into play at the Sparkfun AVC will help with the flying.

This could be achieved with a fixed wing platform with a little thought.

We should have some ground rules (pun intended) you must seek permission to make a model of the building, or natural wonder! You should fly no higher than 130m and the flight should be hands off all the way and you should stay visual with the airframe at all times. Please do not create a model of something in class A airspace unless it's at a recognized model aircraft field.

The flight must be at very least autonomous from just after take off to just before landing. If you can do it all autonomously bonus points! FPV entries will not be permitted.

If you submit your model to Google Earth and get it placed bonus points when it appears on GEFS for me to fly around it. In this case the model might be skinned with images taken from the air.

This is no simple task so it should remain open for six months. Normally I tack time on at the end so to break with tradition lets start the competition on the 1st of August and run all the way to 1st Feb 2014! That gives folks the extension weeks in advance!

Prizes to be announced when I have finished twisting CA's arm. As we know he always comes good.
I am also putting out a call for volunteer judges from the ranks of previous T3 entrants to help me decide. This one is I think going to be very subjective and how attempts are documented is going to be a big factor. 

There is no doubt automated building inspection will be a part of the future for sUAS.

Good Luck, be safe


Now let the traditional but did you mean XYZ questions begin! Oh and if you are tooling around on GEFS as well look out for me as Gary sUAS News, often slope soaring ;-)

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  • That's a really nice flight time Thorsten, especially for a moving multirotor.  Now that's quite a large machine?  How does it handle wind?  Does it fold?

    I weighed my cameras.  Nex 5N with 16mm pancake lens: 320g.  SX260 is 231g as advertised, and WX10 is 171g.

  • T3

    I use two Canon Elph 110, each with about 140g. I changed the props this weekend and made a new endurance test with both cams on board: 37min 37 sec until battery failsafe (13.8V/20% of two 4S 6500mAh) at 4°C. But this is with less payload compared to your heli (I can see at least two additional batteries and my camera mount is lighter (but not as nice...)). To achieve high image overlap I fly at about 8 - 20 km/h. At this speed your flight time should be higher too. For my hexa at that speed there is almost no difference compared to hover time. 

    Yes, the GPS accuracy from the log file is most probably of higher accuracy compared to the GPS of the camera.

  • And I'm actually kinda disappointed in the camera...  It's so heavy for what it is!  Did they put lead in it?!

    Holy cow... 231g!?  The Nex5N is listed as 269g, but I'm not sure if that's with the lens or not.  I'm going to check.

    The only reason I got the SX260 is because of the GPS, and CHDK.  But I have since learned the GPS tagging is better through MP anyway.  And I can run the intervalometer via IR LED (already have a little Arduino that does it).


    Little more looking, Nex5N camera body is 210g, and the pancake lens is 70g.  Going to double check that but maybe I bring the SX260 back after all.

  • I'm hoping for 30 minutes.

    I have flown the heli in standard configuration (no subframe, cameras, etc.) with a single 4S 5000 battery for 17 minutes, with an old battery and very cold weather (-10C).  I'm now going to be using 2 batteries in parallel.  Normally a multirotor would only give about a 50% flight time increase when you do that, but helis respond differently.  But I've done more than just add the battery, I've added the subframe (~300g) and camera, etc.  So I' not going to guess.

    Even if I get 20 minutes with the camera, at 50 km/h airspeed, I'll be happy with that.  It'll be a good short-range/small-area mapping platform that can fit in a suitcase, and doesn't require a catapult. :)

    The BIG question here is the vibration.  Will the mount work well enough.  It's the #1 problem with helicopters.

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    Robert, looks impressive! Nice mount! What is the (estimated) flight time?

  • Well, only a few days left.  I only got as far as getting the machine built. I haven't test flown it yet.  



  • T3

    Stephen, have a look at Three.js. I used it for my model. Same as Sketchfab it is based on WebGL. But it is open source and you could host it on ecosynth. 

  • T3

    So my two day medium quality run failed as well.  I was a bit despondent, but I started my low quality run which took 12 hours.  When it finished, I saw why the previous runs had failed.  It was massive!  Face count in the tens of millions.  Edges were well defined, trees were crazily detailed.  I'm going to cut out some buildings to texture and put in sketchfab, as well as decimate the whole campus down to where I can share it on there.

  • T3

    Thanks for the suggestions!  I know that Photoscan's chunking function would probably help me, but I didn't have time to learn it for this contest.  I think I will definitely get results with medium quality.  The time estimate is only two days!

  • 3692931635?profile=originalBy the way, it was a project with 30 aerial hexacopter shots and 270 handheld shots. Trees were cut out of the 3D model, but some tree shadows on the cliff couldn't be fully avoided.

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