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Oscillation when airmode is off
#1
When I drop the throttle, and air mode is off, I get a lot of oscillating on both roll and pitch axis. Does this mean my D pid is too low?
#2
Technically if you have Airmode off and throttle at idle the PID controller is not doing anything, so your P and D have no effect.
It's best to keep on airmode during flight

If you still get some oscillation when airmode is on, that could be prop wash! One of the harder things to tune out. The effects of prop wash can be increased if you are using chips props, slightly bent props or a bad tune.

How to get rid of it? Well first off if you are tuning use NEW props. You can look up some of joshua bardwell's videos on youtube on tuning. My guys would be to raise P slightly and see if that makes a difference. Just do one axis at a time. You could also adjust the notch filters, a little more complicated, but also helps.
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  • unseen
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#3
It's also worth saying that if you cut the throttle with air mode off and the quad is just dropping into its own prop wash, nothing you can do will stop it from wobbling.
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  • campagnium
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#4
(16-Oct-2017, 05:19 PM)unseen Wrote: It's also worth saying that if you cut the throttle with air mode off and the quad is just dropping into its own prop wash, nothing you can do will stop it from wobbling.

True! - there would be possibilities w the settings on bf, but they would mess up the regular flight, so..
..I found that a gradual throttle onset helps a lot! The smoother the commands, the more time the fc has to adapt: Try starting your maneuvers earlier, and pay attention to the reaction speed of the quad. Depending on how you like your sticks to feel, you might achieve some benefit by lowering p and d-values (..if they're high..), lower d-setpoint weight and keeping transition around 0.6-0.7
I found high yaw rates combined w rc-expo to be problematic/nervous, so paying attention to the relation between rc-expo and super-expo (middle and maximum stick deflection) while keeping the rates (deg/sec) as low as necessary smoothes things out considerably.
Last thing take a look at the throttle pid attenuation. If that one's too low (too little attenuation), maybe your pids freak out at the throttle punch, and cutting the throttle produces some sort of backlash. Rounding the edges of the pid setting upon throttle punches may help, depending on your "regular flight settings". I'm trying to keep p and d as low as possible myself..
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