Huge drone sprayer pids/weight

The problem is variable weight, if I’ll make autotune with empty tank it will fly well but only with empty tank, with full tank unstable.
If I’ll make autotune with full tank and try to launch it with empty it will be fully uncontrollable, it will set huge throttle as he thinks he’s heavy…

So how to deal with variable weight during flight? (for example package drop)

Any other suggestions what to charge for huge drone 20+kg

I’ve always thought there should be a way for the vehicle to sense its weight by hover throttle, and then apply a different configuration based on that… But such a mechanism doesn’t currently exist.

Tune with empty tank, and install bulkheads to prevent fluid from slushing around.

I believe all this are guesses and you haven’t tried real…

The tank if it will be full then the liquid will make crazy the auto tune

Count how many kilos is the full tank and put a dummy load instead of the full tank

There is a value at mission planner that throttle will learn each flight so that you said about throttle dosent exist…

I’ll make an analogy, not sure everyone will understand.

I’ve got a sewer system on my street. Whenever we have a heavy downpour, it overflows and my neighbours start complaining. Whenever we have a drier period, it tends to clog with sht., the neighbours complain, and we have to call the sewer company. Any other day of the year, it just works… you sht, wash it away and it vanishes.

It’s the same with PIDs :smiley:

I just downgraded to 3.5 and it starts to fly perfectly, seems like some issue with 3.6…

Can you tell me how you made your autotune, because I am currently in the blur on this subject ?
Should it be done empty this is not a problem once there will be an additional load on the drone ?

The new tuning page is where you want to start.
https://ardupilot.org/copter/docs/tuning-process-instructions.html

I have already realized all the preliminary stages before an autotune.
I also realized a autotune to empty now the question that I ask myself is what with the load of 10kg additional how will you react opu must I redo an autotune extra ?

Hi, please don’t take my words as a call to action, however, on our 23 kg payload, 45 kg AUW hexa, I have performed the auto tune process unloaded, then I’ve had a series of test flights gradually increasing the payload. I ended up with no need in changing the PIDs, to mention, the auto tune was done with a moderate aggressiveness set, 1 axle at a time.

Thank you Anto6ka for your help. I’ll tested