8. Auto-Pilot Position Following
When the FS9/X or X-Plane NATIVE auto pilot is
engaged the system will drive the elevator and aileron axes to
follow the movement of the AP control actions. When the AP is
disengaged force feedback and flight control will be returned to the
Unless specific special
arrangements are made the CL software will not be able to recognise
3rd party A/P systems and so will not be able to activate the A/P
To disable AP following mode
manually set Tab 4 Item 1 - APF_Enable parameter to zero. The
scaling of the AP following movement can also be adjusted using Tab
4 Items 2, 3 & 4.
NOTE - when this AP following is
active the CL software fully disengages the control axis inputs from
the flight sim via FSUIPC. So control movements applied to the
controls have no effect on the flight sim whilst AP following is
active. When AP is disengaged the CL software re-engages the
V9.7+ adds the capability to
disengage AP by moving the controls when they are in AP-following
mode. The sensitivity of the disengage movement threshold is set in
Tab 4 Items 13, 14 & 15.
(For systems NOT using pot-less
mode the Zero button can be
used to run the automatic zero-finding procedure by which the system
can determine the accurate zero position of the controls (as seen by
the brushless driver cards). This more accurate zero position allows
a more accurate assessment of the actual positions of the controls
and so allows more sensitive movement dis-engage thresholds to be
AP position following uses a
closed loop position control PID algorithm implemented within the
BLDRV-12/24 drives. The PID settings are specified in Tab 4 Items 16
to 24. The BFF_Driver_Test program can be used to tune for suitable
PID settings. CARE is required when adjusting the PID settings as
incorrect settings can cause unstable movement of the controls.
The maximum force levels in
position following mode are capped internally by the BLDRV-12/24
card programming. The cap levels can be raised if your controls are
heavy and require larger forces to move than the default levels.
This will require re-programming of the BLDRV-12/24 cards - please
contact me for information and instructions should you wish to do
NOTE the internal AP operation
of FSX/9 does not use full elevator/aileron actions to control the
aircraft. Because of the this it is difficult to determine where the
real elevator position should actually be when the AP is
disengaged. A sudden pitch movement may therefore occur when control
is retuned to the yoke.
Update - In version 1.07 of the CL
software automatic adjustment of the elevator trim during AP
following can be enabled for systems in which buttons are used
for trim input. It automatically adjusts elevator trim during
A/P following so keep the elevator force in balance so minimising
snatch on A/P disengage.
The feature also provides
a similar function for potentiometer trim input systems - however
this requires additional external hardware.
Update - In V1.210
Heavy Jet Mode 1 is introduced - this
changes the way in which A/P following is implemented for the
elevator axis when the mode is active. See the above link for
details.... elevator trim is used as the A/P control action for
pitch control, and the elevator position is left stationary.