8. Auto-Pilot Position Following
Version beta v9.6 of the CL
software introduces Auto Pilot position following when the software
is used with BLDRV-12/24 brushless drives.
When the FS9/X 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
To disable AP following mode
manually set the APF_Enable parameter in your settings .cfg
file to zero. The
scaling of the AP following movement can also be adjusted using the
in the AP_Gains
section of the .cfg file.
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
the Pry_S.cfg file for each axis.
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 the Pry_S.cfg
file. 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 rapid 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. To minimise this the FFB elevator trim
should be used to bring the elevator force to zero on the CL
software progress bar before AP is disengaged.
I'm still working on this, so
matters should improve in future software versions....!
In general only engage/disengage
the AP when the flight is stable and trimmed.
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. See section 7.2 Other Trim Options
- Elevator auto-trim direction indicator. The feature also provides
a similar function for potentiometer trim input systems - however
this requires additional external hardware.
The automatic trim adjustment
helps to keep the elevator force in balance so that on AP disengage
the elevator does not snatch.
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.