Multiwii Crius SE 2.5 NonUniform Motor Speed Problem

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mamartyacse1
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Multiwii Crius SE 2.5 NonUniform Motor Speed Problem

Post by mamartyacse1 »

Hi Friends

I am using multiwii crius 2.5 SE and multiwii 2.3 firmware platform to develop my X quadcopter . After arming when i increase the throttle initially they get same thrust but after some time(ater 3 to 4 sec) thrust of motor-2 and motor-3 is autometically increasing upto maximum value and the thrust of motor 1 and motor 3 is autometically decreasing upto minimum value. I have trimmed the rc stick and make Roll - 1500, pitch -1500 and yaw-1500 from my TX. my PID values for Roll ,pitch and yaw given below
p i d
ROLL 3.3 0.030 23

Pitch 3.3 0.030 23

yaw 3.2 0.045 30


please help me to find what should I do to fix this problem???? :(

scrat
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Re: Multiwii Crius SE 2.5 NonUniform Motor Speed Problem

Post by scrat »

Did you calibrated esc's?

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mamartyacse1
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Re: Multiwii Crius SE 2.5 NonUniform Motor Speed Problem

Post by mamartyacse1 »

yes.....i have calibrated esc properly by using ESC_CALIB_CANNOT_FLY ..... currently doing some trimming on yaw pitch and roll but problem still persists,,,,,,

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mamartyacse1
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Re: Multiwii Crius SE 2.5 NonUniform Motor Speed Problem

Post by mamartyacse1 »

the graph in multiwii GUI also shows the same reading that I get in actually in the motor . Is it a problem of any signal interference that interfaring the activity of pid??

waltr
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Re: Multiwii Crius SE 2.5 NonUniform Motor Speed Problem

Post by waltr »

Is it in LEVEL mode (ANGLE or HORIZON)? And if the Quad physically level?
Describe in better detail the physical test setup (picture could help).

I have read that some have had difficulty with ESC_CALIB_CANNOT_FLY working properly and manually calibrating the ESCs fixed the problem.
Also, when you turn on the FC board (boot) are you ensuring that the board does not move during the Gryo calibration period. If the board moves this will cause the quad to tilt over when trying to lift off which is the motors are not running at the same speed.
Due the variations in the props/motors/ESCs/power the four motors will run at different speeds but they will not be too different. At 50% throttle I see a variation of about 200 amount the four motors in MultiWii Config display.

The default PIDs are good enough and will not cause the issue you are seeing. It also does not sound like interference.

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mamartyacse1
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Re: Multiwii Crius SE 2.5 NonUniform Motor Speed Problem

Post by mamartyacse1 »

I am attaching the video URL of my problem..... You can easily see in GUI that the board itself supplies ununiform thrust to the motor
please check out this video http://youtu.be/zwi3-gokjok

waltr
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Re: Multiwii Crius SE 2.5 NonUniform Motor Speed Problem

Post by waltr »

Ok, that helps. The opposite motors are at about the same speed so the FC is trying to YAW the Quad.
The YAW value from the Receiver is at 1512 which is telling the FC to YAW. I'll bet all four motors will have near the same value if you move the Yaw stick on the TX to the left. I see in the video the TX YAW trim all the way to the right, center it and ensure the YAW value is 1500. Try that.

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mamartyacse1
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Re: Multiwii Crius SE 2.5 NonUniform Motor Speed Problem

Post by mamartyacse1 »

Thanks, waltr :) :) I have reduce the yaw and made it 1499.... now the thrust is almost same ..... but as i disarm the quad yaw value autometically get reduces to 1486 (insted of holding the 1499 value)...I dont know why it happens :( . About motor thrust I want to say that they are fluctuating so much so is it safe to test the quad outside?? or I have to change the PID settings a littlebit??

Check this video (after rectification) : http://youtu.be/_zMBU6OWA5g

scrat
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Re: Multiwii Crius SE 2.5 NonUniform Motor Speed Problem

Post by scrat »

Video is private.

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mamartyacse1
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Re: Multiwii Crius SE 2.5 NonUniform Motor Speed Problem

Post by mamartyacse1 »

sorry scrat.... i was forgottn to publish it now it is visible i think

waltr
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Re: Multiwii Crius SE 2.5 NonUniform Motor Speed Problem

Post by waltr »

The variation of the motor controls look normal, the FC does constantly adjust these.
I would do the "sting PID tuning" test next to see if its fairly stable and the RC controls are all working in the correct directions.
http://www.youtube.com/watch?v=yvame7QLWbo
Is one of the videos available showing this method.
Or just go for it outside with lots of room and no hard surfaces (grass).

splicer
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Re: Multiwii Crius SE 2.5 NonUniform Motor Speed Problem

Post by splicer »

waltr wrote:Ok, that helps. The opposite motors are at about the same speed so the FC is trying to YAW the Quad.
The YAW value from the Receiver is at 1512 which is telling the FC to YAW. I'll bet all four motors will have near the same value if you move the Yaw stick on the TX to the left. I see in the video the TX YAW trim all the way to the right, center it and ensure the YAW value is 1500. Try that.


I was having the same problem as mamartyacse1, and this solved it! Thank you so much! Was pulling my hair out trying to figure it out!

matrix4life
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Re: Multiwii Crius SE 2.5 NonUniform Motor Speed Problem

Post by matrix4life »

http://youtu.be/Lt9_DPO79Hg

Any idea ? My motors are not uniform too but I do not find the solution.

FengShuiDrone
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Re: Multiwii Crius SE 2.5 NonUniform Motor Speed Problem

Post by FengShuiDrone »

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Last edited by FengShuiDrone on Fri Aug 07, 2015 1:16 am, edited 1 time in total.

matrix4life
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Re: Multiwii Crius SE 2.5 NonUniform Motor Speed Problem

Post by matrix4life »

Ok I will try. But as I see on the web I have an other problem because when I move my throttle command, pitch and roll change too (like in my video). Is it normal ?

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