How to make throttle channel less sensitive for a more stable hover altitude

ArduCopter Copter 4.5
1

In my test flights I’m finding that my throttle inputs to achieve a constant hover altitude tend to overshoot. I have mot_thst_over set to “2” - for learn and save. But as you can see by this chart I’m having to “chase” the proper throttle input.

throttle sensitivity
throttle sensitivity1920×1080 208 KB

I mostly fly automated missions, so this is usually only a nuisance in test flights. But it seems like it’s something I should fix.

The throttle adjustments on my control sticks are very very small - so perhaps I should set an expo on the throttle channel.

But before doing that - I’d appreciate suggestions on parameters that might improve this.

Thanks!

2

If this is in stabilize mode, you can expect very touchy throttle control. You have the full throttle range at your disposal, unlike alt hold or loiter.

Hover learning is not active in stabilize mode.

3

Yes sir - I’ve only been using Loiter and Altitude-Hold.

4

Chasing the throttle position likely hurts the hover learn algorithm. Attain enough altitude that you can put the throttle in the center position and leave it there while the autopilot sorts it out (doesn’t take long). Setting MOT_THST_HOVER to a best guess from the start might help (especially if you are flying similar hardware as a known/previous config).

Ensure you follow the instructions for initial parameters and the follow-on PSC* values after an alt hold flight.

If you have thrust test stand data, we have a new tool that can estimate MOT_THST_EXPO and hover throttle, but that’s a whole other can of worms, really.

5

Good suggestions - thanks!