2 hours ago, Bert Pieke said:

Hmm, not all airplanes have this file accessible.. the Carenado PC12 has it "hidden"..  Will try some others and report back.

Edit: Just tried the RV14, and it feels nice!

The systems.cfg won't be accessible in any Marketplace aircraft, Bert. 😝 ... but it's there for everything else now, including previously encrypted premium deluxe aircraft.

3 hours ago, ryanbatc said:

I will try this but I also think a factor is how trimmed the aircraft is prior to AP engagement.  Most people just engage AP with the plane all out of whack and it reacts aggressively usually.

 

2 hours ago, ark said:

Agree, the plane has to be in trim. Would not make sense to have the AP initially lock onto an out of trim setting.

Al

I completely agree gents.  And slapping the AP in while out of trim will still result in a subsequent harsh correction, with this tweak.   However this tweak wasn't relating to abruptness from trim etc.  It was how MSFS was handling the delta between the AP PIDs on engagement, and those that are preselected (or used by basic engagement modes).

It can be thought of like this;  imagine you're standing on a large 3x3 grid of squares on the ground, with each square numbered 1 through 9.   Someone shouts "6" and you need to get onto square 6 as quickly as possible.   Without this tweak, you're always standing on square "1" and when the host shouts "6" etc, you need to jump to square 6.   With this tweak, when the host shouts "6", you're already standing on it. When he next shouts "4", you're magically already standing on it. 😎

This is simulating the fact that AP servo arms are always connected to the flight control rods and so move with them as the pilot moves the control surfaces (even with the AP off).  When the AP is turned on, the servo is energized and the arm takes over control, right there where it's currently deflected.    = smooth engagement that you should see on any real world AP (that is working properly!).

Edited December 12, 20223 yr by JYW

1 hour ago, JYW said:

 

I completely agree gents.  And slapping the AP in while out of trim will still result in a subsequent harsh correction, with this tweak.   However this tweak wasn't relating to abruptness from trim etc.  It was how MSFS was handling the delta between the AP PIDs on engagement, and those that are preselected (or used by basic engagement modes).

It can be thought of like this;  imagine you're standing on a large 3x3 grid of squares on the ground, with each square numbered 1 through 9.   Someone shouts "6" and you need to get onto square 6 as quickly as possible.   Without this tweak, you're always standing on square "1" and when the host shouts "6" etc, you need to jump to square 6.   With this tweak, when the host shouts "6", you're already standing on it. When he next shouts "4", you're magically already standing on it. 😎

This is simulating the fact that AP servo arms are always connected to the flight control rods and so move with them as the pilot moves the control surfaces (even with the AP off).  When the AP is turned on, the servo is energized and the arm takes over control, right there where it's currently deflected.    = smooth engagement that you should see on any real world AP (that is working properly!).

Interesting. My understanding is most sim APs control pitch by manipulating the pitch trim, and the pitch trim seems to be continually adjusted when the AP is on. Roll is another matter, I don't see the roll trim being used in the same way by the AP.

Al

Edited December 12, 20223 yr by ark

11 hours ago, ark said:

Interesting. My understanding is most sim APs control pitch by manipulating the pitch trim, and the pitch trim seems to be continually adjusted when the AP is on. Roll is another matter, I don't see the roll trim being used in the same way by the AP.

Al

They absolutely do Al.  (At least in most cases - it's possible to set pitch_use_trim=0 in the cfg to have the AP control using the elevator only, as is the case with APs in LSA and very light aircraft, such as those that I fly IRL.  I fly a club TL-2000 with an AP that controls roll and pitch, using ailerons and elevator only - I get lights on the unit to tell me to trim up or down if the forces on the servos become too excessive).

Hence for a smooth AP engagement you certainly do need to be in trim, regardless of this tweak.  The issue with MSFS is that, with the PID values of '0', even if you are in trim, the AP engages abruptly because MSFS momentarily moved the trim to a zero value, before them moving it to the required value.   The PID '2' value sets to as it would be IRL - the AP takes over with the trim where it is currently set.

Excellent hint Bob! Thanks for sharing!!!