Copyright © 2019 Xflight Technologies LLC, Florida, USA
31
L.
PITCH Axis Gain Calibration (in flight)
This step will calibrate the pitch axis only to ensure the gain is set correctly to allow for a smooth
correction to pitch and altitude in flight. Pick a clear area on a good weather day with very little wind for
this test and fly at a safe altitude away from populated areas.
Make sure the roll servo power is disconnected or switched off prior to starting, this test is only for
pitch
. This will likely take a few flights to fine tune.
Make sure to do clearing turns before any
maneuver to ensure there is no other traffic in the area.
1.
Prior to takeoff power up the AUTOPILOT. This will display the AHRS and set the Home location.
Leave the servo(s) circuit powered down
.
2.
Takeoff and fly straight and level at a typical cruise speed at a safe altitude. The AHRS display
should be straight and level.
3.
Select
AP ON
. This will enable the Servo PWM signals and start flight logging. Power up the pitch
servo.
Immediately switch the AUTOPILOT off (AP OFF) or power down the pitch servo if you
experience any adverse reaction.
4.
Wait a second or two, then select
CRUISE ON
to enter Cruise mode. Note the altitude.
5.
The current altitude should not change much.
Immediately switch the AUTOPILOT off (AP OFF)
or power down the pitch servo if you experience any adverse reaction.
6.
Put in a gentle pitch angle for a couple of seconds to change altitude and then release the yoke.
Do the same in the opposite direction. You want the plane to pitch back smoothly and gently to
the original altitude.
Immediately switch the AUTOPILOT off (AP OFF) or power down the pitch
servo if you experience any adverse reaction.
7.
When complete allow the servo to return to a neutral position, then switch the AUTOPILOT off
(
AP OFF
) and/or power down the pitch servo.
8.
If the pitch response is too slow then you will need to increase
PTCH2SRV_P
and
PTCH2SRV_FF
when back on the ground in increments of 0.5 until you are happy with the response
(alternatively, an in-flight tuning kit is available to modify parameters in flight).
These are the
most important pitch
tuning parameters and must be tuned first
.
PTCH2SRV
PTCH2SRV_P
Pitch Proportional gain (default =
2
)
PTCH2SRV
PTCH2SRV_FF
Pitch Feed Forward gain (default =
2
)
9.
You can also adjust the
PTCH2SRV_I
response in steps of 0.1.
