I am starting to fine-tune a large hexacopter with 15 Kg payload capacity for spraying. I have previously worked on small multi-rotors and done Autotune multiple times, but never tried to tune a copter that carries such a significant payload, which is actually reducing in weight over the course of flight. So in need of expert guidance from the community.
The hardware/software setup is as follows:
HobbyWing X8 Pro Power Combo (100 KV Motor, 30x90 Prop)
12S 22000mAH Battery
Take-Off Weight No Payload: 20.5Kg
Pixhawk Cube Black
I started following the Tuning Instructions and set all the parameters as explained in this guide. After a couple of successful flights I was confident to try Auto-tune. I have completed Autotune on all three axis. As the guide suggested, Autotune was done in Most agile configuration with Fully charged battery and No Payload.
Here are the logs from a Manual Flight and Auto Mission after the Autotune. Both flights were done without any payload. Please comment on the current state of the tuning and suggest any improvements that can be worked on.
Now, i want to add 15kg payload (maybe in smaller steps of +5kg) and start spraying. As per the tuning instructions referred above, here is what it suggests to do for large payloads:
@Leonardthall Is this the only change required to safely fly with added payload after tuning the copter without any payload? What about the PID gains, is there any need to re-adjust the PID gains or maybe even run the auto-tune again? How does arducopter manages to control a copter where the weight is constantly decreasing (From 38 Kg Fully loaded at Take-off to 22 Kg at Landing)?
Anyone with experience of tuning a similar setup please share your experience and findings on how to correctly tune such a system.
Thanks for the support as always.