1.9 KiB
+++ title = "INAV tuning tips" weight = 3 sort_by = "weight" insert_anchor_links = "right" +++ Here are some general INAV tuning tips and things I've learned throughout my builds. Keep in mind that these only apply to wings (and maybe planes), not quads:
- There's a known problem with horizon drift. To ameliorate it, use
set imu_acc_ignore_rate = 10
. Setting this low is a good idea, but if it's set too low then the accelerometer will effectively be ignored and the horizon will eventually drift. To reduce the accelerometer's influence, you can also reduceimu_dcm_ki
/imu_dcm_kp
. - To make turns in automatic modes smoother, use
set nav_fw_control_smoothness = 8
. - Pawel says that the idea of the software LPF is to replace the hardware LPF. Leave the hardware LPF set to 256 Hz and set the software LPF to 20-30 Hz, with a looptime of 1k.
Battery monitoring
To monitor how much battery you have left in flight, voltage isn't a good indication because it can sag a lot. mAh is also not a good indication, because it doesn't decrease linearly with voltage. Energy is a better way, using the "Wh drawn" INAV OSD item. In addition, INAV has heat loss compensation for the energy meter, which gives you a more accurate reading.
To calculate the Wh a battery can give, the best way is to charge or discharge it and see how many Wh were spent, if your charger shows you. Another way is to get a rough estimate using the formula no_cells * 3.7 * Ah
. So, for a 1800 4S battery, the maximum Watt-hours are 4 * 3.7 * 1.8 = 26.64 Wh
. You should not discharge more than 80% of that value, or you risk excessive wear to the battery.
For a 4S battery, I go with a rule of thumb: The maximum Wh is mAh / 85
, so for a 5000 mAh battery I'll land after 58 Wh consumed, which is around 80% of the battery consumed and gives a small margin for error.
(Thanks to Michel Pastor in the INAV Telegram group for this tip.)
Last updated on December 20, 2020.