DJI-Dave
Second Officer
United States
Offline
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Here is a post I wrote about gains.
Some info on gains...
The DJI recommended gains are a good starting point. If you are flying a new multirotor with no camera or gimbal they might be little too high. If you have a light disc loading (light weight multirotor) you might be over propped. When a set up is over propped with a light loading, it is hard to get the gains right in the sweet spot. Where it doesn't oscillate (gains too high) or wobble on decent. (gains too low). With a heavier disc loading (heavier multirotor) you have a wider variance of gain settings that the aircraft will fly well in. However keep in mind it will always wobble some on a fast descent, no matter what your gains are set at, because you are flying through your prop wash. It is better not to descend too fast or come down at an angle. Bottom line is you will always need to fine tune your gains.
The Atittude gains controll how the aircraft reacts to stick movements. High gains it will react fast, low gains it will react slow. The lower gains are like adding expo to a traditional transmitter. When gains are high it overreacts when the gains are low it underreacts.
Basic gains are how your multirotor levels itself, and the attitude gains are like stick scaling.
In the Naza software there's a loop, in short, there's two sets of values :
1 : how the multirotor really is, in position and angle
2 : how the multirotor should be,according to your stick inputs.
Basics gains controls how hard the multirotor will try to reach 2 from 1, by itself.
If the gain is too high, it's trying too hard, and will overshoot 2, so it comes back, once again too hard, overshoots again, and it's oscillating.
If the gain is too low, it's slow to move from 1 to 2 and will also overshoot 2 because it does not react fast enough to stop.
Your propellers size and pitch and weight of the aircraft will affect how you should set your gains. Also the altitude where you fly from can have an effect on how you set your gains.
So you can see there's a lot that goes into adjusting your gains.Carbon fiber props are going to need different gains than plastic props. Even if the propeller has the exact same pitch and diameter. And even making a small change like a different manufacture of the propeller can have dramatic results.
Every multirotor is going to be a little different and you will just have to tune it in as best as you can.
This is the order in which I tune my gains.
1) Tune pitch/roll together
2) Tune yaw
3) Tune vertical
4) Once Basic gains are dialed in, move on to Attitude gains.
This is a good order to follow when adjusting gains since there is not a direct correlation between yaw and vertical like there is with pitch and roll.
I feel gain adjustments should be done in Atti Mode, not GPS mode.
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