I would like to show what we have done here in Namibia in developing Inexpensive UAV systems which we are beginning to actively use in conjunction with Namibian Ministry of Environment and Tourism, tasked with wildlife conservation in Namibia, and also for photography missions for the local quarry mines and Salt mines.
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Shown , in order, are three aircraft, GUPPY, fully designed from the ground up and built by me, HORNBILL, built from a semi built kit, the Lanyu-100, and the third, KIWIT, an electric flyer of unconventional wing design.
HORNBILL is fitted with an RF tag tracking system and antenna and flew many autonomous, beyond visual range flights tracking tagged animals, especially Rhino as an aid to the National Parks anti-poaching campaign. The next trial will be with an Infra-Red camera fitted to aid the detection of poachers at night.
Hornbill basic Specifications.
- Wing Span - 2.4meter
- Engine 55cc Twin Boxer.
- Weight 15kg with 3liter gas
- Max TOW - 17Kg
- Endurance 1H 40minute with 0.5 liter spare @ 24m/s
- Min safe speed 14m/s @ 16deg AoA.
- Stall speed 10m/s @ 25deg AoA.
- Max flight speed - 34m/s
it was a lot of fun! See the report: waterberg_report.pdf
GUPPY was designed from the ground up, a full 3D model developed on CAD, and designed to be made from good aircraft grade ply. However, it was built with plain Marine ply in the end, as and exercise in cost reduction. It was designed to carry a hi resolution camera , which was subsequently flown to create geo-referenced imagery for the Quarry miners, as well as for the Salt Works. GUPPY has tremendous STOL performance and can land/takeoff anywhere.
GUPPY Basic Specifications:
- Wing Span - 2.8meter Clark Y 14%
- Wing Chord 600mm +80mm for Junker Flaperon
- 2 Flaperon per wing, each with own servo
- Horizontal stabiliser - 450mm each half span Clark Y 12%
- Horizontal Stab Chord - 220mm
- Each stab half fitted with own servo
- Engine 100cc Twin Boxer. (3W)
- Weight 26kg empty
- Max TOW - 42Kg
- Max Fuel - 8.5liter
- Endurance 5hours with 0.5 liter spare @ 35kg @ 24m/s
- Min safe speed 12m/s @ 20deg AoA.
- Stall speed 10m/s @ 25deg AoA.
- Max flight speed 42 m/s
The electric flyer was actually two Aircraft, PiPiStrello, and KIWIT. Both share wing profile type, Jedelski, and both are V tail. Both are made fully from composite materials.
PiPiStrello has straight wings with dihedral, and was fitted with ailerons, not normal on Jedelski wings – resulting in excessive adverse yaw so was canned…
KIWIT and its prototype flew many flights tool to verify the existence of a Vulture Chick in a nest in a tree out in the desert. We annually undertake a conservation mission where we currently fly in a Cessna 180, spotting Vulture nests in the Sparse Namibian desert regions. When we spot a nest, we fly closer to see if there is a chick, and if so we GPS mark the spot. Often the tree is among a dozen others, so the exact spot is 'close by'..but not easily found when we return in ground vehicles to capture, ring and tag the chick. So we used KIWIT to overfly the nearby area and find the chick again.
See the article in Raptor News - (page 2) Raptor_News.pdf
We have also perfected fully autonomous land and takeoff with KIWIT.
Have a look at these videos for the Auto Launch and land:
https://www.youtube.com/watch?v=dOEVQG9ORuE
https://www.youtube.com/watch?v=exaabnihKhM
Kiwit Basic Specifications:
- Wing Span : 2.4meters
- Weight excluding payload - 3.5Kg
- Max payload capacity - 1Kg
- Endurance - 1hour
- Cruise speed - 14m/s
- Max speed - 20m/s
- Stall speed - 6 m/s
- Takeof in 3meters in still air.
- All composite construction, cabon fibre and glass
And these videos for the flights of GUPPY and HORNBILL:
https://www.youtube.com/watch?v=8iC0jDPDxjc
https://www.youtube.com/watch?v=_3wELMrG3Go
https://www.youtube.com/watch?v=KwQ5QyFnFQI
https://www.youtube.com/watch?v=rdUwaeE-T5c
Have a look at the postings under Aircraft Platforms and Autopilot Hardware for more info.
The autopilot fitted to all these aircraft is called the 'NamPilot' and is based on multiple modules, namely:
AUTUPILOT: an AVR processor based module, 8 PWM inputs from RCS, 7 PWM outputs to servos. This module does the full flight stabilization and navigation/guidance for auto flight, and stabilization for manual flight with autostabilization - mostly used when tuning the control loops.
IMU - Also AVR based, with 3 axis Gyro's, accelerometers and a Bosch I2C pressure sensor.
AIRDATA UNIT: Also AVR based, a smaller processor, with another Bosch I2C pressure sensor, and an analogue static pressure sensor ( Freescale) and a Dynamic pressure sensor for airspeed. (Freescale)
MAGNETOMETER: Also a smaller AVR processor, with a Honewell 3 axis magnetomet, configured in a balancing bridge circuit, ie, the null strap in the device is used to balance out the ambient magnetic field in a control loop. This gives VERY accurate performance, with almost no temperature drift at all, the bain of magnetometer performance!
The Ground Control Station - This is a PC based system and can be anything from a simple, reduced functionality Laptop based system, to the one depicted in the PDF files listed below. This system interfaces to a datalink antenna, with optional autotracker for the antenna, tracking theUAV in flight. It also interfaces to a dual video receiver, built into the video RX antenna. The video from the UAV camera is available in real time on the GCS, and can be recorded. A dedicated configurable Payload control panel is on the GPS operator position, allowing control of the UAV stablised camera, steering, setup, etc. All flight plans are prepared on the GCS, with a map of the flight regime, and all flight paths are shown, as well as the track flown. Numerous flight patterns can be selected, figure 8, square, straight line, circle, loiter, point to point flight plan, etc. Aircraft control loop tuning is also done in real time, during flight, from the GCS.
Take a look at these PDF’s for more info:
imu_flyer_full.pdf autop_flyer_full.pdf gcs_flyer_full.pdf
THATS IT:
This is far too much fun for just two people!!
Comments
:)
That's the difference between directed research versus "playing around".
I don't think UAV will ever be a turnkey system that will be mass adopted. Not in the near future anyways.
It's the same dream that people have of putting a flying car in everyone's driveway. Flying, is just inherently a task requiring skill. The only way that everyone can learn to use flying machines, is when we develop antigravity machines that don't fall out of the sky, if unpiloted.
it is amazing to see what can be achieved outside of the community. we had better pull our socks up :)
Joe,
I think your comment explains exaclty why auto-land, auto-recharge, low-maintenance systems are going to be the tipping point for mass-use. There are so many ways to dip your toe in the water of UAV-use, but the efforts involved in setting up every flight at the moment outweigh the benefits from the flight. It is only when you can send up your UAV on a mission without having to leave your house that they will become useful. That is why I think they will need to be VTOL, tilt-rotor, brushless electric. I can't see any other way of making them easy to use and 'unskilled' to fly. (Hope it's allowed making these guesses, when I have zero-hours UAV flight time to date! thanks)
Stuart
Hi again Gerrit-Jan,
As you say, pity about the sales - not really because of lack of Gov.support, more because UAV's are such a buzz word today, and everyone thinks they can 'just put a UAV in the air, chop-chop, and see where their cattle are, or where the car hijacker is", etc. And when they discover the need for a map, a GCS, the need to know the lie of the land or fly into the hill over the horizon, that 2 hours endurance does not mean 2 hours range with wind etc, then they discover that UAV's are in many cases, a solution in search of a problem...So they buy one or two systems, then they really discover what it is all about, get cold feet, etc. Or, they decide this would be a nice thing to do themselves, why must they pay megabucks to by a system, you can get $100 autpilots al over the place, etc, so they buy a system, and try to copy it or hack it, and two years and $1M later, they are still busy, but cannot lose face to there bosses, so they continue....I have been through this saga so many times, its not funny anymore!
WRT to your project. If you wish to achieve two hours, what is your power consumption requirments during this time? I would try very hard to just use batteries for 2 hours - the power to weight performance using an alternator and associated charger, which is not simple, since it must cope with a widley varying input voltage from the varying RPM alternator, is not good at all. UAV type alt generaly would fit on the prop hub, behind the prop, so there are mechanical issues there to. I have an alt on GUPPY, but I modified the engine - extended the crankshaft out the rear with another bearing support, and used a big AXI brushless motor as the alt. Get 20volts @ 15amp @ 5000RPM. But the weight penalty is around 1.7kg, brackets, alt, charger, etc. GUPPY flies 4 to 5 hours, is 35kg plus, and has payloads power consumption up to 200watts. HORNBILL flies 1.5hours with payload of 20watts, and we use batteries only.
Good luck!
Joe
Hi Joe
On the aircraft side, it's a great deal of work. For my final year thesis project I’m
characterising a possible 2 stroke engine for use in a small <10kg TOW UAV@
4hr endurance. This includes the design of the propulsion system, optimising of
the prop& engine combo, onboard starting and power generation systems,ect.
Seems that for any flights more than 2 hrs, an onboard supply is needed.
The ATE part, visited there with a bunch of UP students about 2 years ago, that is
how I remembered.(Not at UP though) A real shame that they haven’t been able to
sell the aircraft. To me it seems that the South African aerospace support is a
bit lacking. I myself hoped to maybe work at a place like ATE or Denel Dynamics
one day.
On the electronics side, I wish I could get my head around all of it. Studying
mechanical and having to mess more than half the time with electronics is
starting to get a grip on me.
That said, I need to go study...
All the best
Gerrit-Jan
Morning Gerrit-Jan
It is the same KIWIT but to set things straight;
I designed KIWIT, together with F.Varigas, both of us at ATE at the time - I was a director of the company then, since 'semi-retired'... It is sold to only one other country..for trials. I designed the autopilot and hold the full IP rights to the electronics hardware and all the software, as well as the GCS and it software.
JoeNoci
Hi
Any reasoning behind calling it a KIWIT? As far as I remember ATE (Advanced Technologies & Engineering South Africa) has the same type design aircraft with the same basic layout. Same TOW,Wingspan, ect.
You guys can google image it. Looks almost exactly the same. It is sold to a few countries' defence forces.
Anyway, great initiative on the autopilot. The Waterberg report was really insightful.
Regards
Gerrit-Jan
Hello again Brian,
I guess my comment would be the same as the Wiki - 'facts are facts' as they say...The only practical way to reduce the adverse yaw is to balance the drag between left and right wings by having different up and down deflections. This is normal on normal profile wings, but you need to be very careful with high lift, slow flying wing profiles. The higher the wing's inherent lift value , Cl, generally the higher the drag caused by aileron deflection. And Kiwit's wing is quite a high lift profile, so ailerons do not work...Frise ailerons are a band aid, in my opinion - NEVER add drag to counter a design flaw! Add Drag when the result is positive, ie, add drag induce a roll, but never add drag to correct an induced negative effect, such as adverse yaw. The net result is alway loss of performance!
Have fun.
Joe
Hi Joe, your description sounds exactly like the write-up here: http://en.wikipedia.org/wiki/Adverse_yaw in the Frise Aileron area.
My wing is not as high-tech but very similar none the less. It's from a Hobbyzone Extreme. And as you said only the top portion of the wing profile with the bottom open. I've cut ailerons into the wing and tried my best to have the profile be as similar to a "Differential Aileron" as possible. It flies well w/no adverse yaw, at least that I've noticed.
I like the style of the plane so this winter I'm planning on reworking my "boom" and wing mount but wanted to ask and find out if the stuff in the Wiki link is relative to your wing's ailerons.
Thanks,
Brian
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