Stabilization of RC Helicopter with NeuroFuzzy networks

Hi everybody!!!

I'm making a stabilization system for a helicopter, hehehe, another one...

First of all i want to show my hardware:

- ArtTech Falcon 3D

Rotor Diameter: 24.8"
Tail Rotor Diameter: 5.98"
Weight: 19.5 oz.
Length: 26.4"
Servos: 4 9g servos
Transmitter: 6 channel 72MHz
Receiver: 6 channel dual conversion
Battery: 3S 1300mAhr 10C LiPo
Motor: Brushless B20/10T
ESC: 18A Brushless


- The great Arduino as Avionics

- IMU 6DOF Razor ( http://www.sparkfun.com/commerce/product_info.php?products_id=9431 )

- Small arduino shield build by me, just with the purpose of holding and connecting the razor to the arduino.


Software:

- DCM modified by Automatik, 10x a lot man!!! ( i had made some modifications, for making the arduino control servos for pitch and roll)

- LabView VI made by Automatik, 10x again man!! ( with a little bit of modifications )


What have i done so far:

- I've had a lot of problems with vibration!!!! its the thing that had stop everything!!!
- We try several configurations, with foam, and other stuff.
- The configuration that work the best, its a base with rubbers and velcro, a little hard to explain in english, so ill just paste a picture....


In this picture, the heli is showing the base, and you can see the rubbers.


You can see the shield and the arduino, mounted inside the landing gear.


You can see the usb port, its on the back of the heli.


I just uploaded a video, with the first test with the rubbers and velcro, sorry, its in spanish, because it was for my faculty advisor, hehehehe

http://diydrones.com/video/instrumentation-with-rubbers

Vibration Issues:

In the next pics you can see the problems i had with the excesive vibration produced by the helicopter, and this issue make the stabilization impossible!!!! Because the angles are completly crazy!!!

This test was conducted with the DCM filter and half throttle.


This test was conducted with the kalman filter and half throttle.



What do i want right now??

In this moment i just want to focus on stabilization, and mainly in pitch and roll, i will not take care of yaw...



Any help, comment will be greatly appreciated!!!

10x a lot!!

Saludos!!

Views: 1965

Tags: 6dof, Arduino, Helicopter, Stabilization, dcm, imu, kalman, razor

Comment by Jonathan Lussier on January 21, 2010 at 1:13pm
very cool, care to post your implementation? looks cool.
I can see the accelerometer having that much noise but the gyro should be pretty clean. What's the performance specs of your gyro?
Comment by Aldo Vargas on January 21, 2010 at 1:24pm
The accelerometer is the ADXL335

The gyros are the LPR530al ±300°/s range

Datasheet: http://www.sparkfun.com/datasheets/Sensors/IMU/lpr530al.pdf

What part of the implementation would you like??
Comment by Jason Lyons on January 21, 2010 at 4:31pm
Nice progress so far! I am working on the same thing, except with different sensors (and ultra-low budget lol).

Unfortunately I haven't got mine hooked up to helicopter yet, I know I'm going to need to grapple with vibration issues. Your setup looks really nice and neat, I think I'll give it a try!

Developer
Comment by Doug Weibel on January 21, 2010 at 5:02pm
I would spend some time on the mechanical setup of the helicopter. Balance the blades firstto have the same spanwise center of gravity, then add weight at the cg to balance the pair. Pull the main shaft and head and balance the head. Check that your tail blades are equal weight to within .1 gram. And then make sure the main blades are tracking perfectly. Every time you have any sort of a crash, however minor, pull all the shafts, inclding the spindle shaft, and make sure they are true.

If any of that does not make sense the mini and micro heli areas on rcgroups are a great resource.
Comment by Jason Lyons on January 21, 2010 at 7:54pm
I had a thought, that maybe having the arduino connected to the PC while operating the helicopter could be dampening your rubber bands considerably (if you're just letting the cable hang off), which could increase vibration picked up by the accelerometer.
Comment by Aldo Vargas on January 21, 2010 at 9:05pm
Yes, thats a problem!!! i tought on using a xbee module, but the EMI generated by the xbee, its going to affect in a great way the IMU, so, my solution to that is to peal the usb cable, make it very thin and flexible...

I could avoid the communication between the pc and arduino, but i need to record the angles, for the neural network training, or, using a memory logger system, any idea??

10x for all the comments!!
Comment by Jason Lyons on January 22, 2010 at 12:44am
If you power the Xbee unit completely seperately you may not experience too much EMI (besides radiating), or you could try and implement a band stop filter at that frequency on your sensors

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