Hi all,
It occurs to me that I never got around to posting my videos flying my ArduCopter, Cindi Lou, on Mt Erebus last December (2011). I'm at around 10700 ft, but the pressure altitude is around 0.65 bar -- the equivalent of closer to 13,000 ft at the equator. This was on a nice, warm (-15C) nearly windless day. I was pleasantly surprised how well the quad performed in stabilize and simple mode (no sonar, and loiter was unreliable).
I got my APM / Oilpan when they first came out, and that's what's flying in this video. Unfortunately I upgraded to 2.0.49 before going to Antarctica and didn't realize that flight log collection was disabled since I had the atmega 1280 version, so no logs.
This is vaguely related to my PhD research in volcanology. My job on Erebus is to map and study some ice caves that form when volcanic gases melt tunnels into the bottom of the snowpack. The BBC came out and filmed us at work and you can see it in the "Life in the freezer" episode of the BBC / Discovery series Frozen Planet if you're interested.
I'm going back to Erebus for the fourth time this November, and this time I intend to do some serious science using multirotors with APM2 onboard. Some of the caves cannot be entered due to dangerous gasses and / or unique microbiology. I'm planning to fly an autonomous quadcopter down into them, doing SLAM or at least wall avoidance, and measuring gas concentrations. Eventually I'd also like to fly a multirotor down into Erebus' crater to sample gas from the bubbling lava lake. NASA's New Mexico Space Grant Consortium has kindly awarded me a graduate research fellowship for this work, and I am considering an application to NASA NIACS.
Please let me know if you have any advice or are interested in collaborating. Major issues I need to overcome:
- Radio transmission through the snowpack: can it be done?
- Cave wall avoidance. I will probably do this with IR distance sensors, although the MIT RANGE quadcopter-mounted lidar or Kinect approach would be better if I can pull it off. RANGE said they are interested in collaborating wants me to email them again in June...
- Propeller / motor design for high altitudes. Should I be changing the blade pitch for lower pressure?
- Keeping a quadrotor running in a cold environment with acidic and corrosive condensing vapor.
Oh, by the way, I'm now flying a 3DR frame with an APM2, and an Xaircraft X650V8 also with an APM2. Thanks to all the developers, the technology has improving by leaps and bounds! As has my own flying ability...
One more question. Does anyone know of other people flying multirotors in Antarctica? Am I the first on the continent? I hope not, because it would be great to start the McMurdo RC flying club!
Cheers,
Aaron
Comments
With regards to sonar and cold weather: I know that some sonar devices can be calibrated with a speed of sound value (the SRF02 certainly has that feature), or can be configured to return echo time in uS rather than distance. I guess the speed of sound would drop to about 320 m/s, which would be in the 5-10% change region. If you had the opportunity to correct it in software, it shouldn't provide too much of a problem. There would I suppose be a corresponding change in the measurable range of the device, but you wouldn't want to be using something like that at it's measurement bounds anyway. You'd probably want to do some testing before you trusted it to anything though.
Hello Aaron
I'm building a quad for a survey project of the Gomantong caves in Borneo. The quad is not 100 % ready yet. It has two 4 W led lights for flying in the dark. For video and photo's I'm using a panasonic FT3. No Go Pro because what I wanted a ccd sensor. This to avoid jello. Also the lens has an angle of 70° Which is more than wide enough to film in the dark. The distance for good video in the dark is max 5 m. For taking pictures I'm working on an additional flash. The total weight is 2 kg. On the pictures the props are 10x45 but they are at their limit. The final props will be 12x45.
What is working very well is the landing gear. The thing has survived some very rough landings and it just bounces. It's light weight an very robust. But not suitable for sub zero environments because the plastic becomes brittle. Also the four arms are very easily removed from the frame for transport.
For wall avoindance I thinking about putting some sticks on it with some ping pong balls. Ultrasonic wall avoindance would be great but the timeframe to implement this is just to short. I fly visual and the Gomantang caves are very big (50 m wide 100 heigh).
Succes with your project!
Guy
Nice videos Aaron. Now you just need the lift & stability from the build posted a few days ago flying in Jakarta with 25 kt winds so you can deal with normal Erebus conditions ;-)
That's great.
As far as Antartica goes, I know that sonar sensors have trouble with the cold.
If you do go near any caves I would highly recommend building a shroud around your props. A single blade strike against even a tree will bring down a quad. I've seen 3d printed ones and ones made on the cheap with blue styrene foam and carbon fiber bands.
Jason
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