Arducopter in the air with mikrokopter frame.

Hi,

First af all I want to thank every contributor to the Arducopter project for their hard work and commitment.

A few months ago I got hooked to this project and first of all did a lot of reading.

Last month I started ordering the different parts and yesterday was D-day for me because I did my first test flight after some minor problem with bad contacts the IMU headers .

First of all, my setup

APM

IMU

Mikrokopter frame

KDA 20-22L motors

ESC's 30A

APC 10 x 4,7

DIY power distribution

Here are some photos of my quad.

Note, the ESC's will eventually be covered ;-)

Now for my problem: PID tuning!!!!!!

I calibrated everything according to the manuals, uploaded the alpha 1 firmware and used the standard PID values. I did a test flight in stable and + mode.

My observations:

-Front motor and rear motors tend to turn very late.

-Before lift of nose tends to go in the gound.

-When in the air quad tends to drift and yaw to the left

-At a certain height (1,5m) quad starts to oscilate in the role axes

Stable PID values are:

Roll: P=4; I=0,15, D=1,2

Pitch: P=4; I=0,15, D=1,2

Yaw: P=3; I=0,15, D=2,4

I've allready tried some minor changes in the PID values but this cost me some leafs of a plant in the living room. ;-)

I would try to change Roll P to a lower value (3) to minimize the oscilation

Any suggestions?

I don't know the solution to your problem, but I have an identical problem myself. My Arducopter behaves exactly like yours does when it's on the ground trying to take off, as shown in your first video: 2 engines will come on before the other 2, it gets jumpy and tippy, and then puts a propeller into the ground forcing me to abort the take off. My setup uses the KDA 20-22l motors, Turnigy 18A Basic ESC, beta kit arms, DIY power distribution (soldered deans), and DIY aluminum center frame (total weight 900-950 grams). I will watch this thread closely to see what people suggest. Also, as my experiments continue, I'll let you know what I find out. I've done a lot of things in an attempt to solve it: re-calibrated ESC/Motors, re-calibrated RC, re-did the Configurator step, replaced a slightly chipped prop, tightened wobbly DIY motor mounts, changed to heli mode on the transmitter, and so on. This is going to sound kind of strange, and is probably erroneous, but I've had a little better luck taking off from a flat hard surface (like a board on my lawn), than the thick grass. I'm going to do some more experiments on that theory today.

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Vincent Mees October 19, 2010 at 12:16pm

This evening I had some time to do some further tests.
Concerning the front and back motor that don't start immidiantly.
I checked very closly and these motors do start just before left and righthave enough power to lift off.

The nodge that sometimes comes up in video 1 is due to a problem with right motor. I openened it, cleaned it and at the moment it doesn't do it any more.

As it is poring rain at the moment here I can't test outside. So I did some low level flying. Also didsome calibrationon the differnt axes and started changing D Value. Lower that is. Seems to be losing the wobble.

Thumbs crossed that tommorow will be beter weather.

Vincent
Alexander LeBrun October 19, 2010 at 12:24am

Hey Mees what channel are you powering your RX from? Try powering it from like an AUX pin on your APM instead of one of your motor channels and see if that helps.

~Kaotic
emile October 18, 2010 at 4:18am

I have the same exact problem occuring on my setup!

There is nothing wrong with the hardware setup 'cause i have flown it with the gaui 330x brain and never had problems.
I have calibrated escs, configured correctly the configurator and have only two motors spinngng correctly.
The others two saty just still.
If I give the minimum power all 4 motors spin correctly. As soon as I increase power, two of the stop working completely....
Could it be relatedto the APM firmware problem? (brownout voltage too high)?
Best regards,
Emile
Alexander LeBrun October 17, 2010 at 10:57pm

Hey Mees try adjusting your End Point Adjustments on your Transmitter for your throttle...I was seeing the same thing you filmed that the motor levels would slowy start to drop and I tried adjusting my EPA on my TX before I went ot the transmiter calibration and it seemed to help with the slow fading of the motor levels. I might have read somewhere before that you should have your EPA's set to 100 before TX calibration but maybe I'm just smoking crack.

~Kaotic
Moderator

John Church October 16, 2010 at 6:26pm

Mees, curious- what battery are you using?
Öncü Kayalar October 16, 2010 at 9:22am

Mees,

I have the same frame. I tried KDA 20-22L and Turnigy 2217-20 with APC 10x4.7 propellers. It is very stable with Turnigy using default PIDs but unfortunately I could not find a stable interval with KDA. I belive KDA 20-22L does not enough power.
Robert Beatty October 16, 2010 at 7:04am

I don't know the solution to your problem, but I have an identical problem myself. My Arducopter behaves exactly like yours does when it's on the ground trying to take off, as shown in your first video: 2 engines will come on before the other 2, it gets jumpy and tippy, and then puts a propeller into the ground forcing me to abort the take off. My setup uses the KDA 20-22l motors, Turnigy 18A Basic ESC, beta kit arms, DIY power distribution (soldered deans), and DIY aluminum center frame (total weight 900-950 grams). I will watch this thread closely to see what people suggest. Also, as my experiments continue, I'll let you know what I find out. I've done a lot of things in an attempt to solve it: re-calibrated ESC/Motors, re-calibrated RC, re-did the Configurator step, replaced a slightly chipped prop, tightened wobbly DIY motor mounts, changed to heli mode on the transmitter, and so on. This is going to sound kind of strange, and is probably erroneous, but I've had a little better luck taking off from a flat hard surface (like a board on my lawn), than the thick grass. I'm going to do some more experiments on that theory today.
Vincent Mees October 16, 2010 at 5:42am

These are the ESC's
http://www.giantcod.co.uk/speed-controller-p-402443.html
Sebastian Gralla October 16, 2010 at 4:51am

do you have a video to show it?
what ESCs do you use?

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Arducopter in the air with mikrokopter frame.

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