Hello.
I tried to look for previous topics regarding the following (could not).
I’m working on making sense of the file
PX4\PX4-Autopilot\ROMFS\px4fmu_common\mixers\AAVVTWFF_vtail.main.mix
Using the following references:
- [URL=https://github.com/PX4/PX4-Autopilot/blob/master/ROMFS/px4fmu_common/mixers/AAVVTWFF_vtail.main.mix]
- Adding a New Airframe Configuration | PX4 User Guide
I wrote in red my understanding of the control laws (in plain English). I’m looking for someone to confirm my findings.
Aileron mixer (roll + flaperon)
This mixer assumes that the aileron servos are set up mechanically reversed.
M: 2
S: 0 0 -10000 -10000 0 -10000 10000
S: 0 6 10000 10000 0 -10000 10000
Means:
dA1 = -roll + 0.6 flaperon
M: 2
S: 0 0 -10000 -10000 0 -10000 10000
S: 0 6 -10000 -10000 0 -10000 10000
Means:
dA2 = -roll - 0.6 flaperon
V-tail mixers
Three scalers total (output, roll, pitch).
I don’t see the 3rd one
M: 2
S: 0 2 7000 7000 0 -10000 10000
S: 0 1 -8000 -8000 0 -10000 10000
Means:
drv1 = 0.7 head – 0.8 pitch
M: 2
S: 0 2 7000 7000 0 -10000 10000
S: 0 1 8000 8000 0 -10000 10000
Means:
Drv2 = 0.7 head + 0.8 pitch
Motor speed mixer
Two scalers total (output, thrust).
I only see one
This mixer generates a full-range output (-1 to 1) from an input in the (0 - 1)
range. Inputs below zero are treated as zero.
M: 1
S: 0 3 0 20000 -10000 -10000 10000
Means:
dTout = dT
Wheel mixer
Two scalers total (output, yaw).
This mixer assumes that the wheel servo is set up correctly mechanically;
depending on the actual configuration it may be necessary to reverse the scaling
factors (to reverse the servo movement) and adjust the offset, scaling and
endpoints to suit.
M: 1
S: 0 2 -10000 -10000 0 -10000 10000
Means:
Not needed
Flaps mixer
Flap servos are physically reversed.
M: 1
S: 0 4 0 5000 -10000 -10000 10000
M: 1
S: 0 4 0 -5000 10000 -10000 10000
Means:
Not needed