Yaw imbalance message

Hello everyone,

We were flying today the Arducopter 4.1 version and in one of the flights, we constantly got the message “Emergency: Yaw imbalance 10%” with the value changing to 11% and 12%. After reading the documentation, we figure it out that this means that the yaw action is getting saturated, and that the higher the imbalance the closer the vehicle gets to not having more control power for the yaw action. However, it seems to us that the warning was triggered a long way before reaching the threshold set in ATC_RAT_YAW_IMAX=0.5. Checking at the motors, it seems that the quadcopter still has control energy, since the difference between the motors PWM is not higher than 100us:

Please find the log below:

In summary, we were expecting the warning with an imbalance of 50%. By the way, the new Firmware is growing on us so far.

I think these messages will be revised to a lower level of priority in upcoming versions.

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Yeah, low percentage warnings are now gone, it will be 75% and over in the next beta.

But you should probably still see if you can fix your 100us imbalance if you can.

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Thank you! we will definitely review the hardware. I gather the fact that it was a little bit windy contributed in some proportion to persistent yaw corrections, but we will keep an eye on out hardware.

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I think having a motor imbalance of 100pwm is somewhat common. If you can get it less than that then that’s great but I think it won’t cause many problems.

As others have said, the messages should go away for most users once we release -beta4 which I hope will happen next week.

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