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View Full Version : Discussion Raptor 90 hovers and flies on its own finally.


zozie
Dec 28, 2007, 02:25 PM
So finally my raptor has a life on its own. It will now hover and hover taxi and fly to GPS points.
Here's the list
Raptor with OS90 SZH
2X Gumstix waysmall 400xm 400MHZ running Linux
1X Hitec 24 Servo MR-C3024 Microcontroller Board
2X ultrasonic range finder
1 X Hokuyo PBS-03JN Infrared Range Finder
2X G190 Piezo Mini Gyro
1X Futaba 611 on tail
2X XTend™ RF Modems (900MHZ) , 1 one on raptor, one on computer for manual control if need be.
1X SFE ±3g Triple Axis Accelerometer Breakout Board (ADXL330)
1X BU-303 USB GPS Receiver
2X 4000 MAH 2S Lipo to power all this
1X camera with downlink
1X optical RPM sensor on fan

So after 2800 Lines of C++ and assembler code, draining my finances and managing to mount all of this and still be able to lift off and fly safely with 1.3L of fuel (which was only enough for 22 mins) it finally hovered and flew a 1 square km circle without a glitch and landed on its own.

Now the challenge:

I need a better RF modem solution and the range is fairly limited(3000 feet urban 40Miles clear sight) for manual control in case the linux computer goes (unlikely). There is now one optical sensor strictly for the engine speed, assuming that the clutch is not slipping. I need two of them, one for the rotor speed also in case of an engine failure which would now just kill it. If I mount a second sensor on, I could get it to auto manintaining rotor RPM and when the proximity sensor kicks in, it would flare and land with minimal or no damage.

I need to put all of this into a better ariframe with a gas engine for more power and endurance, which then represents another issue. I wrote all the code for mechanical mixing, reworking the whole thing for CCPM will be time consuming and more complicated due to the inability to put gyros on each channel on top of the accelerometer.

The big old question.
Gas or Electric????

I tend to be more of an electric guy due to the lack of vibration, noise and smoke but with the prices of batteries that may have to wait.

The raptor proved to be a very good airframe but with this weight (16lbs) its fairly weak and balloons at high(er) speeds.
I still need an airspeed indicator and a barometric altimeter as I hear the GPS isn't too accurate at judging speed and altitude.
Top speed recorded so far was 45 KTS (@1900 RPM on the head)which isn't too fast but going bigger and stronger should speed things up a bit.

Your input is appreciated.
I'll post pictures when I get home and put a video on youtube showing onboard as well.

Jack Crossfire
Dec 28, 2007, 02:44 PM
Looks like 2 things helped the most:

1) Large size and weight
2) Heading hold gyro

Noticed there's no magnetic compass and no DGPS. The Futaba 611 must be providing heading information. Won't even ask for source code.

zozie
Dec 28, 2007, 02:48 PM
I do have a compass on it as well but you can make it GPS driven as well.
As far as the source code goes, I WILL make it available once it's bug free but I'm afraid of people harassing me due to them crashing their stuff. :p

robe_uk
Dec 28, 2007, 03:21 PM
I need to put all of this into a better ariframe with a gas engine for more power and endurance, which then represents another issue. I wrote all the code for mechanical mixing, reworking the whole thing for CCPM will be time consuming and more complicated due to the inability to put gyros on each channel on top of the accelerometer.


Sounds like an intense project. Have you looked at the spartan AP2000i? It is a flight stablizer but uses mechanical mixing input (ie futaba sw1) and outputs to ccpm control

http://www.spartan-rc.com/products/ap2000i/ap2000i.htm

zlite
Dec 28, 2007, 03:49 PM
Zozie--huge congrats! That's a massive project and the coding alone deserves a PhD (as Jack can attest). Really looking forward to the video and source code. Please keep us updated on your progress.

Kaptah
Dec 29, 2007, 09:38 AM
How fast GPIO interrupt response time can you get from a Gumstix + Linux combination? 10ms? Were you able to do a fast enough (10 times per sec?) control loop to control the aircraft attitude accurately in real time in Linux?

Jack Crossfire
Dec 29, 2007, 08:13 PM
Would be nice to know:

How long it took to get full autopilot.
What the biggest challenges were.

mlbco
Dec 29, 2007, 09:36 PM
I found this link in another forum, don't know much about this. It may be a useful starting point for helicopter UAV platform development:

http://www.mscompositusa.com/helicommand-3d--an-autopilot.html




Steve

cbergen
Dec 30, 2007, 12:41 AM
If Mechanical mix is what you need in a big gasser, try this http://69.65.123.251/~bergenrc/GasEB.php

Crash Pilot
Dec 30, 2007, 06:54 PM
Zozie

Well done. What a great acheivement.

Any one know if this has ever been done on a mini Heli like a Mini Titan or TRex?


Crash Pilot

zozie
Dec 30, 2007, 08:01 PM
It crossed my mind to try something like this on a Trex or any similar sized heli but crowding everything on it would be complicated.

Yeah I think the bergen may be the way to go :p

zozie
Dec 30, 2007, 08:05 PM
Would be nice to know:

How long it took to get full autopilot.
What the biggest challenges were.

I've been toying with the idea for over 3 years. I actually got into RC for this reason and I started on planes, then was shortly infected with helicopters over 2 years ago and my focus shifted on to that.
Obviously the biggest challenge was $$ due to the fact that I have killed about 8 sets of blades and 3 full airframes while trying and it
s nowhere near done. As I'm getting deeper in it I'm begining to realize how much code I'm missing..... We'll see. I gotta put a team together eventually and focus on something bigger and faster :)

A trin turbine would be nice :o

wadiprawita
Dec 30, 2007, 08:23 PM
Dear zozie,

Congratulations !!

You do not use any gyro, so I assume, the manuver is slow (to avoid centrifugal effect), or is it forward-stop-turn-forward again ?

You use inertial mechanization or just use the tilt from accel and position frpm GPS ?

One more thing, do you use mechanical damper (anti vibration) ?

Regards

-doni-