Some pictures to start...
Thought some of you may be interested in this build as I intend to build an aircraft capable of 1 hour flights to map large areas in order to Create some Digital Elevation models for GIS mapping purposes. Initially i will be doing this for experimental purposes. I know there are a lot of rules and regulations in around commercial photography etc.
I will be focusing on the following
I know this is a highly specialized area, but i do have some of the above from asking various people on here (initially posted about this in my blog area, but that was wrong place, so posting here...)
Right where to start...
I have selected the Ursus Airframe for this build as it seems to have a large wing and space for enough batteries to give slow, stable flight for up to an hour or more in some cases. It has been talked about on here before
Material: EPP and wood
I'll try and post more pictures than words.. .as they are more interesting to look at...
Airframe arrived, fuselage part assembled,
Wooden spas glued into wings, Glass rods glued into tail booms
Fuselage glued together, with, wooden wing joiners glued into place
Wings joined, APM arrived, sticker stuck to horizontal stab.
After a few weeks of tinkering, my APM2 has arrived, And with much help from Chris and Michael I have managed to get HIL mode running pretty well in Xplane 10. I have been familiarising myself with the MissionPlanner as much as possible. Learning how the PID settings work.
Servos implemented, Undercarriage on.
I have also been playing with the Canon CHDK (Canon Hack Development Kit) on an ixus 80 and Intervalometer. Which is how i will be taking the photos from the plane, I wanted to see how long it can take pics for before the battery dies, I took pictures every 120seconds, and it took 81. Review was selected though after each picture, And i will be taking pics quicker than that. I created a time lapse from the window. Not that interesting, but its all part of the learning curve.
I have upgraded the nose wheel undercarriage to a more robust strut with steering as well. This should give plenty of ground clearance for the Camera Gimbal
Testing the placement of the electronics, need to decide where to put the APM2, R149DP Futaba RX and the Camera IMU. Plenty of room in here for 2 x 5000 3s lipos! AUW is currently 2.7kg!
It is clear from the flight path, that the plane is snaking across the track, so for my next flight I am going to reduce the crosstrack gain, are you using the config file from the wiki, do you want to post your crosstrack values?
Jerry - have a look here, http://diydrones.com/forum/topics/skywalker-users-pid-question - Look at the First reply on page 1 by Rigel. It shows some PID values for the Skywalker. I am going to check mine later when i'm back home. Already noticed the Cross track on mine is 3000, and Rigels is 2000. That's a good start!
Looking good, colour is better and although slighly less focused the stitching looks to be a big improvement on your last stitched image posted on the 15th .
Did you use the grid tool in mission planner to create your flight plan?
Cheers Martin, yeah i am learning how to work CHDK, and general photography properly, next time i will use a roll mount and vibration dampening foam/gel to ensure the picture have no motor blur.
I absolutely used the grid tool in the mission planner, it worked a treat, just need to get APM2 work with the URSUS so i can use the roll stabilized camera mount. But from what I have seen of APM2, it is easy to use and i am confident i will be able to get it to work with a different airframe.
I think i will be a week or so fixing the URSUS and building the internal roll dampened gimbal -
Will post progress as and when...
Put these pictures through photosynth Richard they will work well.
I would do Gary, but i dont think photosynth can output a nice mapped image, it seems to load one image, then flick from one image to the next, I dont think the pics are good enough to do anything with them What were you thinking photosynth could do with them? I'd like your thoughts... r
Just to throw another option at you I am getting the attached sort of results out of Autopano. It seems to be doing a reasonable job of 'georeferencing' even without control points. The pic is a lower resolution of a 12Mb file stitched from 81 pics. You might like to give it a go.
Your image looks really good, Upon a close look at your images, it looks like most of them have been taken vertically straight down, most of my photos were taken on a diagonal. As the plane wasn't flying level for much of the flight.
I am in the process of building a roll controlled mount for my URSUS airframe mentioned earlier in the thread.
Have you got any sort of camera stabilizer on to get the vertically down photos?
For each flight of 50 to 100 pics I usually end up manually removing about 10% before processing (the ones that show up as obviously not near vertical).
I have not bothered with any form of stabilisation. I do make sure the motor is well balanced to reduce any vibration. As per the pic the plane has 2 cameras embedded in the wings (one is NIR). Luckily there is no dihedral in the wing so both cameras point the same way. Autopano seems to be able to take out the distortions from non vertical pics. I have much less of a 'vertical pic' problem with this than my SkyFun (elevon delta plane) as the SkyFun can only stay on track by rolling. I will keep in touch.
I have a similar mount for my camera in my skywalker, I only have a single camera in the left wing, so put some coins in opposite wing at the end to balance, the plane is balanced perfectly. I struggled with how to keep motor vibration down to a minimum. I laid some sticky-back foam tape in the hole, and used hook and loop tape to secure the camera in, but that didnt do a good enough job, so ended up using super tough ripstop tape around the wing accross the back of the camera.
I can see you have some sort of band around the camera, how did you secure them in?
Nice canopy by the way, did you make it? The clear one that comes with the plane broke on its first outing!
Because making roll stabilized gimbal is easier than tuning pids (which is probably why the planes are not flying the flight path,)
I am pursuing that avenue as well with my larger plane...
Here is the progress....plenty of foam to stop blinkin motor vibration! I worked out as the plane follows the flight path to the nearest 30 metres, as long as the plane covers a certain area, and the camera is stabilized, i will get good coverage!
To hold the cameras into the wing is just a fairly tight rubber band.
Reduction of motor vibration is done mainly by having balanced propellars that are not damaged at all.
The actual SkyWalker canopy is what came with the plane from HobbyKing some 6 months ago. I have noticed there are a few construction variations around the world.
This weekend I will be trying out the new PID settings you found; many thanks. J
You'll have to let me know how you gt on with the PID tests, As i am hoping to do a flight this weekend also, its too windy at the moment, wind about 30mph. Whats the max you would fly in?
And how do yo accurately balance the prop, do you use one of those prop balancers from greatplanes? I was looking at them, and if you need to make a blade lighter, do you just lightly sand it, or do you cut off pieces of plastic?