Hi everyone,
For years now we use model aircrafts as a hobby or job, and for many years as aerial platforms for aerial photography and mapping. So after many discussions here and reading, I will begin here an UAV application that I think and prepare from student and I hope that now I have the background to make it happen. The reason I post the project here is because I learned all about model aircraft from aeromodelling.gr and everything I know for autopilots from diydrones.com
I began my first efforts for knowledge and hobby with the famous Telemachus (similar to telemasters). The Telemasters are well known to most of you and they have been used as such platforms, although satisfactory results have pluses and minuses that we saw in corresponding topics. So after studying, planning and design of many commercial and non-commercial UAV’s, i resulted in the formation of one new platform that meets ALL of my conditions:
- Be able to lift all the flight equipment, control, transmission, cartography, FPV
- Have a decent flight time (~ 20-25 minutes)
- Have a great airspeed spectrum (cruise speed 30km/h, 70km/h max, stall 20-25km/h)
- Flight stability (dihedral 5-6 degrees)
- space and protection for all equipment
- Wingspan MAX! 1.90 m
- Detachable wings and body for easy transport
- Rigid and durable construction
- Servo on the moving parts for easy changing, maintenance, replacement
- For sure electric powered
Finally anything else you suggest...
And we begin:
Uploaded with ImageShack.us- Wings are a joint design by the famous Skywalker, the predator RQ-11, an israely Twin-boom (I did not find the name) and some personal touches weight ~ 400gr
2. Equipment detail
- Battery 250-500g 3s and 4s from 3000-5000 mah
- Futaba 8fg transmitter
- Receiver Futaba 20gr 2,4 8ch
- ESC GAUI 66Amps 60gr
- Servo 4x12gr digital
- Ardupilot mega for avionics
- 900mhz xbee pro telemetry kit
- transmitter for fpv 5,8 Ghz 200mw ~ 50gr
- camera 10 gr for FPV in the nose without PAN-TITL
- mapping Camera in the belly with pan-roll-stabilization-target tracking 200 gr (I need tons of help with that)
- Target tracking mount 90gr (with Servos)
- 2 camera 6-10 gr at the wingtips for 3d image acquisition
- 136gr Scorpion bl motor SII-3014-1220
3. fuselage,
After much thought for the space, size, versatility, the total weight, I decided to give to my plane a “Stick” form, ie a square carbon fiber of 1,5cm witch all equipment, (wings, rudders etc) will be screwed on it and can change position depending on the setup and CG. The aerodynamic "outfit" will be left out as a surprise at the end of construction, the only hint is that the total weight of the planking will not exceed for 1 meter aircraft 60gr and it will be practically unbreakable!
4. horizontal and vertical stabs are in shape and size same with those of the skywalker, but is made of balsa & depron (6mm) with normal layout (not T-Tail) and the servos are mounted on them
Everything is screwed! Because a. I do not want even traces of glue, and b. the weight. Also I will be literally be able to unscrew everything and put it in a Bag.
5. Finally, all data from the cameras (dual 640 * 480 3d, RG NIR) will united directly to the base station in a GIS environment, ArcGIS, there the data will be fed into an algorithm that can calculate the terrain, the sunshine and hence the potential evapotranspiration (pennman), various health indices (NDVI, RVI, etc.), leading to immediate conclusions about the course of cultivation.
A little backround,
I am from Athens- Greece, I work as GIS technician for cadastral agencies and forest mapping cartography, I studied agriculture technology and environment management. The whole project has to do with my phd witch I hope to combine spatial data, agriculture techniks and knowledge with remote sensing and the calculation capabilities of GIS.
I purchased a full ardupilot mega kit from udrones ready and tested, I used it to fly right out of the box my custom made telemaster (img below)with perfect results, but I needed something more, so I am building my own airframe, I update my APM’s firmware and now I need some help to make it come to life.
I hope that are many people in this forum that we share the same interests (and passions) and I believe this could be a nice post-think tank to gather all opinions for remote sensing applications. Also I am willing to help everyone who wants to know more about photogrametry and GIS issues, image rectification and so on.
At this point I have to thanks, my employer Silva- Natura , www.greekwings.gr for providing cnc machinery and knowledge for the wing construction and www.nemhobby.com for sponsoring most of my rc gear.
Thanks in advance,
James Stefanakis
Comments
Great Job James...
My bird soon will be on the skies.
I forgot to mention its name, Skyptrovamon was the name of Zeus eagle witch he send him to watch over mortals or sometimes took his form.
oejang aja, Try to imagine that the image final "shape" its the same with the lense shape.. the more curve your lense have the more distortion you get in image (very obvious with gopro). for accurate mapping i would suggest narrow lens with sony nex and more pics with 30-40% overlap, you can simply increase flight alt a bit to find the best solution pictures vs area, and tsek the extrems of the photo for fisheye-like effects.
Thank you james...
We still amteur in GIS :)
by the way currently we are working for plantation mapping, we couldnt find any camera wide enough with high resolution. The option now just sony nex with 16 mm lens and gopro using flat lense from ragecams. Do you guys have any recomendation ?
i forgot!! all servo cables pass throw carbon rods with a ferrite ring at the end το eliminate interference from fpv rx or esc.
a pick from the fuse mold
Good morning everybody,
Rowland, you realy have a beauty out there, little large thow, thanks a lot for the good luck!!
Thomas i suppose all of us want these great features for free, but i believe what we realy need is scientist "translate" their analyzed data to usable knowledge, for example : i take the pics, and make my analysis... farmer doesnt want to know NDVI, or nitrogen ppm.. he wants to know when and how much it costs to fertilize with simple words like a bucket every ten trees.. like diydrone, many guys with extreme ammounts of knowledge dont just play with PID and math.. they made for us something simple and beatyfull... plug n fly.
Chris, i suppose you solved the error problem, i can se all the pics from another pc, i can upload them here if you want also.
Now, some details i missed in the main post, APM lying in a topless megahousing box made fro carbon fiber all walls have anti-vibration Adhesive Pads with Aluminium Pad and its right under CG at the same angle with the wings incidence angle, firmware is 2.24, with airspeed, mag, voltage and latest Mission Planner
I copied some parametres from Skywalker but i dont understand one.. the airspeed offset,
Also i made an exact model to G5 simulator and it flyes, connected and play with x plane sim, how i can tsek my plane and autopilot to x-plane sim with out the model??
anybody have any idea for the pitch roll stabilization???
Well, I suppose my point is this: many archaeologists and landscape historians would love to have a technology where the learning curve for acquiring the data and for post-processing the data is rather low...throw in the technology of aircraft design and development using open-source technology and many would likely shy away because the time to learn what they need to learn can be time intensive. Yes, acquiring data through a paid service is expensive too, as is satellite imagery. I just would like to think that A) it might be possible to put together a fairly inexpensive airframe and electronics system (which I think we are starting to see regularly on diydrones and rcgroups), and B) an open-source solution to photogrammetry and point cloud analysis that is comparable to something like QGIS...simple to analyze data, not overblown with features that people dont need or want, and, yes, free! Ive tried to use Photosynth exporting to mixed success...I wonder if Microsoft really understands how helpful it would be to download pointclouds easily???
I really enjoy the postings and the work that all of you do. I have yet to build a UAV because Im still learning about RC and aerial photography...but I may have to take the plunge and just do it.
Can you please repost your images? They've all gone 404. You can embed them in your post here.
thanks all of you, for your good words and your efford trying read my english, every help is needed!!
Eduarto, thanks in advance!
oejang aja, super photos you have a fleet out there!!
Thomas, i think i solved that problem, machines are just machines, its all about the data that means you take what you give.if you import in any desent GIS or imagine aplication "perfect" data such as, still and level images, accurate, pitch roll yaw, omega phi kappa, flight and terrain alt, gps data, then its a matter of seconds to produce a "perfect" orthomosaic for example. So all we have to do is try eliminate the wicker points of civilian UAV's, such as low GPS Accuracy and pitch roll camera stabilization. For the first issue i have two solutions: A. Grap some contol points manualy, or just place at least 6 visible targets on ground like a red circle or deep blue triangle etc and then using any clasification method give coordinates instead of target type. B.For the second issue (here i need your help) i know that there is a code for copters, i dont know how i put it on my Arduplane. My real issue is to transfer images on line and export pitch roll yaw compass and alt from the exact time of the photo taken in simple text to feed my rutine in ArcGIS or Autocad map. offcourse cost is great issue, but at the other hand you wouldnt be able to do anything without a hi res topografik map or hi res elevation data witch are expensive too.. i hope some day those data will be free for public.
NIck, Great great job its very interesting indeed.. and its flying! iam just dreaming.. :) keep up, we need posts like this.
Vladimir gas engines are great, but i dont have a clue how they work so im little afraid trying now, maybe in my next project.
We are doing this already here www.hawkeyeuav.com Its not easy, but once you get it sorted its workable.
Good Luck
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