[ Walgett, New South Wales - Australia ]
Around here doing mapping with a Skywalker X8 isn't exactly news. Still, it's exciting when you finally figure it all out yourself and get to enjoy the fun of watching the plane fly over while taking hundreds of photos. A big thank you to everyone here that has gone before and to the Canberra UAV team who I fly with on weekends for all the help.
So last week Jack Pittar, CUAV pilot, and I headed out to a rural Australian town to partner with the Dharriwaa Elders Group who are surveying areas of cultural interest. Using a flying wing equipped with a Pixhawk and Sony NEX 7 camera we managed flights up to 29 mins long capturing over 900 photos. We uploaded the photos to MapsMadeEasy and the next day we had orthomosaic maps that were 3.4 pixels/cm resolution for the DEG to merge with their land survey data. We flew at 110 meters high using a 16mm lens on the Sony camera at approximately 17m/s which required the camera to shoot a photo every 1.3 seconds.
The plane had plenty of flight time on board with two 4S 5 amp batteries. The flights we did only required 30% of the battery capacity with an average current draw of only 6 amps. We opted for a bungee launch system which has been working very well. Using Ardupilot we have the plane set to start the motor after it accelerates adding to the safety of the launch. We have been doing traditional landings which we found were difficult to control on dirt tracks so we will be looking at adding VTOL capability to the plane. We found a folding 12x8 prop to work best with our motor. We found that a Mystery ESC caused so much noise in the plane that the camera tripping circuit would not operate so we replaced that with a 40Amp opto ESC. During the take offs the current is spiking to 42 amps so we have a 60 amp ready to replace it with.
Our road trip was great fun and I'm sure we will be doing more of this work in the future. On the way home we stopped in to meet a land owner who has 35,000 sheep and cattle to discuss how UAVs might be useful for monitoring stock. Next month we hope to fly even further to assist a research institute monitoring the water quality of a thirty two kilometre long creek.
Enjoy some photos from our trip at Flickr.
Comments
Good question. Lots of people here have much more experience with flying wings than I do so let's hope they reply. I can't imagine it being much of an issue. The pixhawk is great at keeping it at altitude. I don't think cumulus clouds would give you much of an effect at 400' and under. Again, hopefully someone with a bit more experience will let us know.
That's sounds good. Just asked because I'm in a planning phase of mapping project, and one of the potential aircraft is a flying wing. Curious, how's a flying wing perform in summertime, when there's strong thermal activity, with visible cumulus clouds.
I really don't know. The report only give you a quality rating for the overlapping sections. The entire map, except for the edges of course was quite dense with high quality reported. I really don't think there many if any missed images. Of the three services I've used, DroneDeploy, MapsMadeEasy and processing with Pix4D none seemed to be effected by not using a gimbal. The plane does manage to stay quite level during flying or maybe Ive just been lucky?
What was the percentage of failed images, due to no gimbal on board?
We haven't flown in windy conditions yet so I can't comment about that. However, if you are using it for mapping you wouldn't want to fly in much wind because the plane will be flying too fast downwind for the camera to keep up. One of the challenges we found was to keep the plane flying slow enough to give the camera time to trip for the resolution we wanted which was under 4 pixels/cm.
Thanks for the pictures, they give a good idea of the setup.
Any concerns about flight behaviour during the windy days ?
One of the reasons we decided on the X8 is that the camera is very well protected. It's quite far up in the belly of the plane. Here's a pic of the bottom. I've had to cut a larger hole for the 16mm lens but as you can see the camera is so far inside the plane that it's quite safe.
Nice trip, I enjoyed the photos.
How is your Nex7 fitte inside X8 ? Do you have protection for it during belly landing ?
I am tempted by X8 for mapping, because of large place inside, but I am afraid a large wing would be very sensitive to wind.