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Detune to stop ground oscillation

Open lthall opened this issue 1 year ago • 3 comments

This pr provides the ability to reduce the gains of roll, pitch, and yaw to remove ground oscillation while landed. Each axis has a gain reduction variable that is set when the aircraft is landed. The gain returns to normal in 2 x ATC_INPUT_TC.

This is a common problem on aircraft with flexible landing gear. It is often seen as a yaw oscillation during spool up on more solidly built aircraft also.

lthall avatar Jun 20 '24 07:06 lthall

@lthall I'm sure this will be popular. Do we need to have both Roll and Pitch parameters? I wonder if we can imagine a frame where we'd want them to be different.

rmackay9 avatar Jun 24 '24 23:06 rmackay9

@lthall I'm sure this will be popular. Do we need to have both Roll and Pitch parameters? I wonder if we can imagine a frame where we'd want them to be different.

I think for heli there could be significantly different gains between pitch and roll. But I don't know if the same backoff factor could work for both axes.

bnsgeyer avatar Jun 25 '24 00:06 bnsgeyer

I considered this but I believe it would be a mistake to not separate them. We don't want to compromise control authority unnecessarily. There are numerous aircraft that have significantly different ground interaction modes between all three axis.

lthall avatar Jun 28 '24 14:06 lthall

@IamPete1 Sorry mate, I didn't understand what you were asking.

lthall avatar Jul 21 '24 22:07 lthall

@IamPete1 Sorry mate, I didn't understand what you were asking.

The ATSC message contains the used values of the angle P scale and the rate PD scale if not all ones. The logging should "just work" with your changes, but it would be worth double checking just so we can track what is going on. You should see them slew up and down, Once they get to all ones the log should stop.

IamPete1 avatar Jul 22 '24 01:07 IamPete1

image

lthall avatar Jul 22 '24 03:07 lthall