When using RPM control, the mapping between thrust and RPM is usually an almost perfect quadratic, so you should probably use THR_MDL_FAC = 1 to make it quadratic. However, let me double check that last point.. The value of this parameter should not change when you change motor / propeller, since thrust is almost always a pure quadratic vs rpm.
Hi @Alex-Kushleyev , did you manage to find out if THR_MDL_FAC should be set to 1 or should i calibrate the thrust curve?
PX4's docs specified in https://docs.px4.io/v1.12/en/config_mc/pid_tuning_guide_multicopter_basic.html that if the ESC is a RPM-controlled one, no tuning is required:
For PWM controllers, 0.3 is a good default (which may benefit from further tuning).
For RPM-based controllers, use 1 (no further tuning is required as these have a quadratic thrust curve).
But i noticed from ModalAI's reference params (eg Seeker's https://gitlab.com/voxl-public/flight-core-px4/px4-parameters/-/blob/master/platforms/v1.12/Seeker/Seeker_v1_param_rev_A.params) that the you guys did a calibration regardless
# Dyno test shows this model should be 0.90
1 1 THR_MDL_FAC 0.90 9