To tune the TECS, a helpful resource is the official TECS tuning guide. Make sure you have run an autotune beforehand, and continue with the tuning below.
In tuning, there are three stages:
LIM_PITCH_MAX=4500(centidegrees), or something similarly high. This is the maximum pitch you'll be achieving in FBWA, and you don't want to be limited by this while trying to tune.
LIM_PITCH_MIN=-4500(centidegrees) or something similarly low. This is the minimum pitch you'll be achieving in FBWA, and you don't want to be limited by this either.
You should perform the measurements in four stages, all in the FBWA mode:
Fly straight and note down:
Set the throttle to the maximum throttle percentage from the previous step and start slowly pitching up until your airspeed equals your trim speed from the previous step.
If you're higher than that speed and need to climb more, change
LIM_PITCH_MAX to something higher and try again.
Set the throttle to 0 and start pitching down until your airspeed equals your trim speed from the previous step. Note down:
Keep the throttle at 0 and pitch down until you reach your desired maximum speed from step 1.
If you're lower than that speed and need to pitch down more, change
LIM_PITCH_MIN to something lower and try again.
You're done with this step.
After you have the above measurements, you're ready to tune things. You can use the automatic calculator:
Otherwise, you can do things manually, following the steps below, but you should really use the calculator instead.
For the level flight measurements:
ARSPD_FBW_MAX(m/s) to something a bit less than the maximum airspeed you achieved in level flight.
THR_MAX(percentage) to the throttle percentage at max speed.
ARSPD_FBW_MIN(m/s) to the slowest speed you could turn at without stalling (maybe go a bit higher for some margin).
TRIM_ARSPD_CM(cm/s) to your trim speed.
TRIM_THROTTLE(percentage) to your trim throttle percentage.
STAB_PITCH_DOWN(degrees) to the pitch angle that keeps you from stalling.
For the ascent measurements:
TECS_PITCH_MAX(degrees) to the pitch angle you measured.
FBWB_CLIMB_RATE(both in m/s) to the climb rate you measured.
For the descent measurements:
TECS_SINK_MIN(m/s) to the descent rate you measured.
For the max descent measurements:
TECS_PITCH_MIN(degrees) to the pitch angle you measured.
TECS_SINK_MAX(m/s) to the descent rate you measured.
Last updated on September 07, 2021. For any questions/feedback, email me at email@example.com.