First of all some background...
Having spent a good 2 years playing about with an Skywalker, Ursus and a Canon camera running CHDK, and designing my own uav, which actually flew recently ,I have come to the conclusion that flying wings may just be the best type of platform for short range aerial mapping tasks to create DEM, DSM models for GIS purposes.
The Skywalker was okay (but quite fragile, and now in pieces!), but I think it is too small to fit a roll gimbal on it. And I've found that if pictures are taken on a slight angle, it is very difficult to use software to tile them up nicely. this is my best effort, but far from perfect. The roads on the right do not line up as the camera must have been on a 45 degree angle when the picture was taken. (click for larger resolution) - It was taken using an ixus80 attached to an URSUS Airframe
Realizing that I need to use an airframe that can accommodate a stabilized roll gimbal, i started to design and build my own twin boom design. It took 6 months from initial design, to first test flight. It has a wingspan of 2.4m - AUW of 5kg, and a flight duration of around 30 minutes with 2 x 5000mah packs. However it needs a heck of a lot of room to take off and land, something i don't have in the areas i need to take photos.
Picture of twin boom plane...
What are peoples experiences with using flying wings for this reason? I have the following types of flying wings, and wondering which one is the best to begin with?
I have been using the 60" wing to test the APM2 and 3dr radios. And was using the URSUS (now in pieces after a nasty crash!) as a test platform to practice with the Canon CHDK Kit.
Here's a few pictures of the wing and camera....(click images for larger version.)
My question is how straight forward do you think it is to fit a roll stabilized gimbal to any of the above airframes?
Hi Alex, your setup looks good, you should be getting more than 13 minutes of flight time from a 2200mah though.
From memory, I am simply using shutter speed priority, and using a shutter speed of over 1/1600 if possible. Auto ISO, focus infinity.
I am simply starting a script on the ground, and letting it run until i land, then i simply stop the script.
Hope that helps. rich
Hi blog, Apologies for not updating you in a while, here is something interesting I put together recently..
A small reconstruction of three cliffs bay on the Gower Peninsula in Swansea, South Wales...
Using X5 wing, APM 2.5, Visual SFM, and Blender...
It worth noting the quality is low due to my poor spec laptop not being able to cope with a dense reconstruction...4GB ram, no GPX processor etc!
Richard that looks amazing!...Ive been able to get VisualSFM to work but have had issues with trying to process the 3d data and create a model using CMPMVS and Meshlab. I assumed it was my computer's lack of RAM and GPU power, but your example proves me wrong. I going to try the Blender Approach.
Dear Richard and all, thanks so much for these very fruitful discussion. I am really a new kid on the block [just started part-time 6 months ago] in using UAV for mapping and building now my first flying wing with fuselage [based on some of the designs in youtube, thanks very much to rctestflight, flight riot, FPVTromso, Experimental airlines, conservation drones] to carry camera. I have been dealing with a social-ecological issues in particular in tropical rainforest and coastal areas [mainly Indonesia] for years and there is a need of having a rather "cheap", reliable and rather easily operate-able UAV as the idea is to have updates of a forested area more often. I also use opensource mainly. For this purpose I have bought APM 2.6 , and I really wonder if you all know or have any idea if it will work [in particular the way points flight] with DX4e Spektrum transmitter ? Thank you so so much for any inputs. Why I consider DX4e transmitter ? as I attempt to build the cheapest possible UAV Mapper that it can be accessed by "trained" and responsible rc-pilot from the local community members. Thanks very very much and I really appreciate all this sharing knowledge here. Warm regards, Irendra
Hi Irenda - whilst you could get away with using only 4 channels to fly a flying wing with throttle and mode change channel. that tx will not be good enough, as it doesn't have any switches for mode changing.
Ideally you need a minimum of 6 channels on the TX with switches. if you want to get the best out of the APM then you need the best transmitter you can afford. I use a Hitec aurora 9, but a dx6i could work as a start...
Many many thanks for your answer and insight. At least it is possible to be done with a rather "fossil" transmitter, that's what I need to know. Thanks lot Richard. So, how's going with your flying wing for aerial mapping? I am really interested in exploring [and using] this. I am at the moment building a flying wing myself based on the knowledge I got from Ed of Experimental Airlines, FPV Trond, MyGeekShow, RCTestFlight. I try to build FPV49 now and will try to use it very soon for Aerial Mapping. I would love to exchange more with you and the others of course on this initiative [aerial mapping with flying wing], thanks so much and let's keep on exchanging.
It must be winter as I don't see too much activity on the blog. It will be spring here in Northern BC soon and we are itching to get out and do some more flying.
We want to get the top heaviness out of the X8 to improve performance. We find that we have to make the nose really heavy to avoid stalling. It works great with a heavy nose and is easy to control but it is costly in amperage and air speed as we are always pushing into the wind with our nose up in the air to maintain elevation. We are also finding that our photography is not as flat as we would like so we want to add a single axis gimbal for our camera.
With those problems in mind we worked on an X8 modification this winter and have almost completed an X8 underbody made of carbon fiber and kevlar. There is also an opening where we can mount our gimbal. We are hoping with the deep belly we can lower the center of gravity below the wings and get better performance. The gimbal will work in the roll using APM's gimbal function and a digital servo.
Have not began to use the carbon fiber and kevlar yet as I have never done this before and I am afraid of wasting the material. If anyone has any suggestions how to ensure a good piece comes out of the mould I would appreciate any suggestions before I dig in.
Here are the developments on the carbon fiber under body for the X8. Cleaned up the mold and waxed it to fill in some blemishes. I had no idea what I was doing with the carbon, Kevlar, or epoxy so I guessed my way through it with help from a lot of sites on the web. Made a few mistakes (which I will not make again) but it did not turn out too badly for a first attempt. I must now trim the edges and mount the gimbal which I have yet to construct. The gimbal will also be made of carbon fiber. I videoed the entire process and I will post it on my YouTube page when I have the entire project complete. The finished under body was surprisingly lighter than I expected considering how much epoxy was used and weighs about the same as the foam under body.
Some updates from my side:
- after playing a lot with Canon camera parameters I think that I have found the right values;
- cruise speed is around 65km/h;
- using a 2200mAh battery(only 1300mAh consumed) , 12 min of flight can be achieved, 13km total length.
I'm thinking to move to FX-61 wing (smaller cruise speed), anyone is using it ?