Hello forum,
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?
- jp-si 48" span Zagi
- Scaled up 60" span jp-si Zagi (hot wire cut by myself)
- x8 2m wing
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?
Replies
Hi Richard,
yeeeeh, love the catapult launch, success at last. great job. it makes the launch process so much easier and repreatable. I found that I usuallly need a 5mm up trim to make the launches good, I set up a mix on the tx to make this eaier to repeat.
flight testing tomorrow if the weather holds!
Video update...I've finally got the catapult launching successfully 100% of the time, The x5 shoots up with batteries and camera...Here's a clip from yesterday, the wind was blowing about 10mph, but I think that this will easily launch in no wind. I probably don't even need power until the aircraft has left the rail...
I did get a dataset of photos, however due to the landscape (1m high grass) changing every second due to the wind, My trial of autopano GIGA, and Microsoft ICE are unable to stitch the photos together well. I'll see if my trial of photoscan can do any better....!
This is what we are dong with VisualSFM.
Pictures taken with Canon S90 on a quad 75-100m high. These are early experimental point cloud results. We are still figuring out the best angles for the camera.
I tested PhotoScan, VisualSFM and PhotoSynth, and by far VisualSFM produced the best point clouds!
Successful Auto flight with X5 on Arduplane 2.73....I've downloaded the high res logs from the APM and it shows very good performance given the confines of the flight path. The params are completely standard, however on FBW-A the bank angle was no where near 45 degrees. But I don't think that is going to be a problem...
If anyone knows how you can show the waypoints and the actual flight path ( log from the plane, not the .tlog) on the same screen. I can replay the mission from the .tlog, however the 3DRs cut out after 50m. So need to use the logs from the plane.
Here is the way points and actual flight paths from flights 1 and 2...
Have you looked at RVJet ? It already have pan-tilt buil inside...
Better results with Microsoft ICE after removing some of the Opaque images...It has successfully stitched quite a few more of the images, however the roads and tree lines still don't join up as nicely as i'd like....I think it's mainly due to the height i was flying at, and I am using two different photo sets from two consecutive flights.
Still not good enough though!!
First attempts at mapping with the x5... I have finally managed to get it airborne with the camera on board, after failing abismally to hand launch due to the weight, the catapult is finally pulling it's weight and getting the x5 flying...(no video of launch yet).
This was also my first auto flight with the new 2.73 arduplane firmware, which seemed to work okay, however I am not getting anywhere near 45 degrees bank angle on full left or right stick...so looks like tuning is necessary. I would have thought the new L1 controller would have been better than it was though.
I did two flights, which were confined to small boundaries, as i was testing the new software and didnt want to allow the plane to go too far away, hence the pretty abismal results from the stitching...
Here are the camera and flightpath parameters i used for this flight:
1/1000, ISO400, 328ft AGL. (it was 2 hours before sunset, hence the dark images)
Here is Microsoft ICEs attempt at stitching the images from the first flight, ICE was unable to use two photo sets....(click for 2000px version)
and here is Autopano GIGAs attempt from both flights (click for 2000px version), better, but no where near what I'm sure AGisoft Photoscan could churn out...
On the next attempt I am going to do the following, which should drastically improve things....
Here is a screen shot of the telemetry data received from the first flight, the 433mhz 3drs are pretty rubbish on UK Regulation settings...
Fingers crossed for some better flights thursday eve....
R
Small update, I have just got back from the field and can confirm the x-5 flies with the camera installed...However the catapult needs a bit more pull, There was a 10mph headwind which just about got it into the air, On a calm day I dont think it would have worked.
The plan is to get some bigger pulleys and stronger bungee chord to get a bit more pull...The good new is the x5 flies with the camera on board, and CG seems to be okay, about 5mm of reflex may be needed though, either that or i need to level the plane better on APM start-up.
Going to do the upgrades this week for potentially some photo taking next weekend!
R
x5 catapult - first test launch with x5. So, after tinkering with bungees, elastic chord and some pulleys, I think i have got the catapult ready, and throwing the plane far enough to be able to try some power launches at the field tomorrow...
The plane was fully loaded with batteries and dummy camera, Fingers crossed if i point it into wind and apply full power mid way up the rail, it should fly with no problems.....!!
R
Hi all,
Small update, haven't really had the time to do much on this project for a little while, but have made some progress over the last few days on x5 number 2 and the catapult.
Having discovered the jaws method to hold the wing in the catapult wasn't really working, i've gone for a different approach (not tested yet). Basically aluminium plates and bolts in the wings which have counter sunk tops so shouldn't cause too much friction.
Parallel to this I have been building up another x5 with mostly the same electronics, except it has an apm 2.5 with cover, cheaper servos, and an Optiima 9 receiver. It also has the new 2.72 firmware with the L1 navigation controller, which i am looking forward to testing next week. It is much easier setting up Elevons with the new mode parameter. As you can leave your tx in normal aircraft mode.
I'll hopefully be taking pics from the plane soon, but I don't think i'll be able to hand launch it now due to the increased camera weight, It was hit and miss before (about 80% of launches successful using the frisbee launch method.)
I'll hopefully be posting some test glide launches tonight if i'm successful! fingers crossed.
R
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