First APM2 Build for Aerial Photography to create DEM,DSM for GIS purposes - Ursus Airframe
Hi Forum,
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
- Best Airframe for the job, including some brief build information
- Suitable Cameras for the project. (Canon Point and Shoot cameras using CHDK)
- Camera Stabilization - already made a basic pan/tilt gimbal for my Skywalker using the FY21AP
- Ardupilot APM2 Learning with Trial and Error
- Software to create the Digital Elevation models.
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...
Airframe
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
Some Stats...
Wingspan: 2200mm
Material: EPP and wood
I'll try and post more pictures than words.. .as they are more interesting to look at...
Day 1
Airframe arrived, fuselage part assembled,
Day 2
Wooden spas glued into wings, Glass rods glued into tail booms
Day 3
Fuselage glued together, with, wooden wing joiners glued into place
Day 4
Wings joined, APM arrived, sticker stuck to horizontal stab.
Day 14
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.
Day 23
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!
Tags: APM2, Canon, FY21AP, GIS, Gimbal, Photogrammetry, Ursus, chdk
Replies to This Discussion
-
ModeratorPermalink Reply by Gary Mortimer on -
You could use the point cloud to make a map. I am sure you have read KBs book though. He is the master around here.
http://www.suasnews.com/epubs/
MapKnitter is another great free tool for sorting images
http://publiclaboratory.org/notes/gonzoearth/5-10-2012/print-maps-p...
-
Permalink Reply by Richard on -
A 66 page book! Wow I wish I'd known about that 6 months ago, thanks for bringing it to my attention, I will read it cover to cover.
That software also looks good, and free to use.
Cheers for the valuable information Gary,
Rich
-
Permalink Reply by Jerry Cresp on -
Gary; you are right, this is a very good book and I should have read more of it before wasting a lot of trial and error air time.
You have convinced me to try MapKnitter.
I must confess that I am trying to generate maps from stitched pics and are continually concerned about accuracy and ways of checking accuracy. I am yet to get out with a RTK GPS unit.
Keep up the good work; your comments are invaluable.
-
Permalink Reply by Richard on
-
Jerry, Would you mind pointing me in the direction of how to make a NIR camera?
Cheers
Rich
-
Permalink Reply by Jerry Cresp on
-
I forgot where I got my prop balancer, but all I ever do to the props is sanding.
I find that flying the Skywalker in more than ~20mph winds is not fun and depending on the surrounding terrain, can be too bouncy for taking pics.
Regarding the NIR camera I lashed out and bought 2 Panasonic Lumix DMC-TS3. For one of these I paid an extra $300 to have it converted to NIR at a specialised camera repairer. The model was recommended because of being drop proof and dust proof.
Yesterday's flights in very calm weather were not good. I collected my Skyfun from 30ft up a tree. And the Skwalker refused to go into Stablise mode without the Elevator chattering uncontrollably. I am hope a firmware upgrade will fix it (please). So I haven't tested the new PIDS.
One step forward and 2 back........
-
Permalink Reply by Richard on
-
Does anyone have any ideas on how I can get the Standard skywalker to fly closer to the flight path, There was little wind (< 5mph).
The facts
APM2 & Skywalker
No Pitot airspeed sensor
Standard Skywalker param file from wiki (XTRK_ANGLE_CD 3000.000000 - XTRK_GAIN_SC 100.000000)
The Flightpath
-
Permalink Reply by Richard on
-
Update: 3DR Radios & Pitot Sensor Header pins soldered in (got an electronics expert friend of mine to do it for me ;-) ). Hopefully with these I will be able to remotely send new PID values in flight to tune the Skywalker to fly the flightpath better.
I am hopefully going to run through the standard PID calibration flights tomorrow as well with the Skywalker, I will also post the working Skywalker PIDS for others if they need them.
Hopefully the Pitot Sensor will improve the navigation. I am also going to potentially re-maiden the crashed URSUS with new Roll gimbal, How long does it take to get a crisp vertical picture!
-
Permalink Reply by James on -
Hi Richard,
I have been out for flying too last two weeks. I saw you made a lot offwork and progress with 2-3 airframes!! well done.
For the params.. try these for starters, I think they are better then wiki's. Also move your CG 5mm forward, check your rudder throws, give them a bit more range. pitot will give you better throttle usage.
The good news is that Dev team re-enabled mount on arduplane (check here ), so we can hope for a roll cam stabilization on next release!!
Be carefull with live PID tuning, you are a very good pilot, i suggest use the FBW tuning presigure
Other great news is that Google earth, supports corner image georeferencing, you dont have to be a GIS expert to overlay your captions on map, just go to image overlay/ insert your image/ location Tab/ use the other method mentioned/ drag corners to the desired location.. you should do something like this:
Its also a good trick, to understand how roll stabilization affects image skew.other news:
inspired by your questions, i pushed my cannons potencials! i made Quad sandwitch firewall ( CF-Dow-PLY-CF )with rubber washers to dumpen vibrations. with 35% throttle i managed to take 150 pictures at 1/125 sh. speed!
I wish you happy flying-tuningJames
-
Permalink Reply by Richard on
-
Hi James, Cheers for sending through some better params for the Skywalker, I will also complete the other mods as you suggested regarding centre of gravity and rudder authority.
That's excellent news about the Arduplane camera mount stabilization, I am currently working on two simultaneous projects/airframes, which i will merge when I find the best bits of each.
Project 1 - Skywalker APM2 with camera in wing. Next steps are to test the pitot and 3dr radios at the field, and have a play with the telemetry to understand it better. Also learn PID tuning for when i move the APM into the URSUS.
Project 2 - URSUS, after the crash its been almost repaired with CF in wing, and I have also built a roll gimbal for the back of the plane. Worked out the camera could not roll and fit in the fuselage, so i have cut out the rear end of the fuse to make way for the camera, wasn't going to post this until I have made a flight with it, but here it is in progress... Unfortunately the URSUS is going to weigh in at 2.65kg after the repairs! And the wing extensions didn't help the flight, so have been removed for testing... so now I have a heavier plane with less wing area!
That's good news about being able to do that on Google Earth, i'll give it a try with my beach cliff pictures. Hopefully with the roll gimbal I will be able to simply process my images with Microsoft ICE and get perfect results!
The weather is improving here, so may do a flight this afternoon, ISO Auto, 1/500 shutter speed, i'll post results if any good!
Cheers
-
Permalink Reply by Jerry Cresp on
-
What!!!
Georeferencing in google earth.
I have to try that.
Are there any tricks???
J
Weather here is wind and rain so I can't try the new PIDs yet but will let you know thw results.
-
Permalink Reply by Richard on
-
Update:
Project 1 - APM2 in skywalker tuning
Flew the plane again last night with pitot sensor enabled, and the same PID values from my first flight, just to see if the Pitot would make a difference. It does not. so need to load the new PID file i have to see if that improves things. There was only about 3mph wind, was hoping for better results... Most of the photos were also at 45 degree angles with the camera embedded in the wing. How are people getting vertical shots with no stabilization?!?!
A Typical Random photo from this mission... ISO 400, Shutter: 1/320th, focus: infinity
As most of the photos are like this, Microsoft ICE and Autopano Giga could even find 2 photos to stitch together out of a total of 64 photos. I did discover an option in Autopano to enable multiple viewpoints, but didn't work still. I'm going to reduce max bank angle, Going to try the SkywalkerJim Param file which has a max bank of 25. Pitot is now reading 8m/s indoors, it may need sending back to the shop.
Project 2 - URSUS Camera stabilizer
Flew the URSUS for the first time last night since its crash when the wing fell off in mid air. It didnt fly well at all and need 100% throttle to sustain a moderate climb, and about 60-70% throttle to maintain altitude. My poor repairs have made it too heavy, and now it doesn't fly well at all :-(. Video of take off, climb, and landing....
Most of the photos were actually pointing straight down, however when i needed to use aileron, the camera mount moved as well (mount and aileron are connected via a Y lead)... was trying to do rudder turns to eliminate this where possible... As it was getting a bit late, most of the pictures were quite dark, on the same settings as above, iso400, 1/320th, infinity.
There is a significant amount of vibration blur from the motor, The camera was encased in a ply box lined with foam, but clearly not the enough foam. And as the motor was on full throttle most of the time, this didn't help. Good news is that the vertical photos have been achieved, Bad news is that a new airframe must be purchased that can handle a roll mount and APM guidance!!!! any suggestions.
(ps. the fpvraptor i purchased earlier in this thread is probably not upto the job as it has a pvc fuse, which probably shouldnt have a hole cut in it!)
thoughts....
-
ModeratorPermalink Reply by Gary Mortimer on -
You could make your photo runs longer, and turns wider, give the platform a chance to level itself out.
I only use flying wings, taking a wild guess standard airframes have a huge vertical area and might just be more easily blown off track.
That said KB does very well with his glider based platforms.
Social Networking
Top Content
Contests
Season Two of the Trust Time Trial (T3) Contest has now begun. The fourth round is an accuracy round for multicopters, which requires contestants to fly a cube. The deadline is April 14th.A list of all T3 contests is here.
Groups
-
Melbourne
47 members
-
Japan ArduCopter Group
51 members
-
Agricultural UAVs
132 members
-
ArduPlane User Group
691 members
-
ArduCopter Italian Group
87 members
Advertisement
© 2013 Created by Chris Anderson.
Powered by
