Autopilot controls the rudder, and it shouldn't.
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Just took this topic for a test drive, and while I agree that given the AP in this plane should be a single axis AP (minus the ALT hold convenience JF added) at no point did I see the rudder or the rudder pedals move under AP control. Be it in the 15kt crosswind or in heading mode or using the roll knob...or even using the rudder trim.
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@nickd27 said in Autopilot controls the rudder, and it shouldn't.:
During my testing I did find some unusual behaviour with the yoke when using the autopilot in roll mode (not heading mode)
https://youtu.be/XdIMYYLtihEStrange, I'm not seeing that behaviour. The roll mode appears to work correctly for me left and right.
EDIT: That was in the Arrow III. Will check in the Turbo.
EDIT 2:
Just checked again and now I see what you're seeing (in both the Arrow III and the Turbo Arrow IV. I'm guessing the Warrior will be the same but I don't have that.)
- Autopilot ON and in ROLL MODE, straight and level.
- ROLL SWITCH to left (or right) and plane rolls and turns as expected.
- While still turning, change to HDG MODE, leaving ROLL SWITCH to the left (or right).
- Plane steers to heading bug and straightens up.
- Change to ROLL MODE (ROLL SWITCH still turned left or right) but it does not revert to ROLL MODE.
- Turn ROLL SWITCH back to centre and only then does ROLL MODE engage.
Also:
- ROLL SWITCH still turned left (or right).
- In HDG MODE and plane turning to the heading bug.
- Before reaching the heading bug, switch to ROLL MODE.
- The plane stays in HDG MODE, continues turning and straightens up at the heading bug (i.e. even though HDG MODE is switched off, it stays in HDG MODE).
- Turn the ROLL SWITCH to centre and only then does it come out of HDG MODE and engage ROLL MODE.
And there's more. After the step below (copied from above):
- The plane stays in HDG MODE, continues turning and straightens up at the heading bug (i.e. even though HDG MODE is switched off, it stays in HDG MODE).
- Then, without doing anything else, try to use the yoke to control the plane and boy, do you get a wild ride!! The plane becomes almost uncontrollable but this can be recovered by switching the autopilot off.
Before I raise a support ticket, can you confirm whether any of that is how it works in real life or not?
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@sender46 I have not flown with the Autocontrol III autopilot in real life so I'm not sure exactly how it works. I do know that typically you would have the plane flying straight and level before activating the autopilot and typically you would already be flying the heading you have set it to (if in HDG mode) so it kind of makes sense that the roll mode doesn't activate until you set it to straight and level - but I'm not sure if that's how it would operate in real life.
Definitely the graphical glitch where the yoke seems to match the roll selector on the autopilot is a bug though
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@nickd27 said in Autopilot controls the rudder, and it shouldn't.:
Definitely the graphical glitch where the yoke seems to match the roll selector on the autopilot is a bug though
The yoke and the ailerons are mechanically tied together with cables, so the two should always move together... But, you are correct that the yoke seems to be tied to the ROLL knob position instead of following the ailerons!
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@Nickd27 and @RetiredMan93231 I thought it strange that it stays in heading mode even when the heading mode is switched off (until the roll knob is centred) but it appears we don't know if that is wrong or not.
So the only thing we're sure is wrong is the yoke tied to the roll knob instead of the ailerons? I'll let you raise a support ticket, Nick, as you picked it up.
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@sender46 said in Autopilot controls the rudder, and it shouldn't.:
So the only thing we're sure is wrong in is the yoke tied to the roll knob instead of the ailerons? I'll let you raise a support ticket, Nick, as you picked it up.
This logic was used as the PID used for roll control causes lots of small fluctuations in the position of the ailerons that is not very noticeable on the exterior model but looks odd and distracting when shown by the yoke position, which 'flickers' and doesn't necessarily show a logical position for the selected bank. I'll have to see if there is a way to add some 'smoothing' code for the yoke but either way hopefully this is a minor sacrifice in realism.
Roll mode only engaging when the roll knob is centred, the aircraft is banked less than 10 degrees and the roll rate is low is a mixture of real-world AP logic and attempts to tame the unpredictable MSFS AP system. Allowing roll mode to engage outside of those constraints causes even less predictable behaviour. We'll continue to tweak/improve it wherever possible.
The AP remaining in heading hold with the HDG button off has now been fixed.
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It looks like the default AP behaviour in MSFS (as used on comparable aircraft like the C172) is to have rudder input for yaw, as determined by the 'nav_yawPID' values in the ai.cfg. We will need to test how the AP behaves without those inputs.
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Have you noticed they changed auto rudder behaviour is SU7 ?
There is an explicit "Auto rudder" as in FSX/P3D.
Before auto rudder coordination was enabled by default. It could be overridden using hard rudder input but wasn't necessary.
Amazing how many people have been coordinating their turns with their rudder pedals.
Now it states that auto rudder on, will auto coordinate and reduce crosswind effect on takeoff.
Not only is the irony of this placebo not lost on me, but may explain a lot of the instability issues people were complaining about over the last 12 months.
Many were convinced it wasn't auto coordinating because of a lag when turning. But they were wrong.
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@martyn Well, tried it myself, P, I and D values to 0.0 on the 'nav_yawPID' and now the AP doesn't use the rudder anymore. Didn't find any adverse reaction so I'll keep it like that. No more yaw kick when disengaging the AP.
Don't know what could happen if you let the copilot fly the aircraft, but I never do that, so I don't care. -
@gabe777 said in Autopilot controls the rudder, and it shouldn't.:
Have you noticed they changed auto rudder behaviour is SU7 ?
There is an explicit "Auto rudder" as in FSX/P3D.
Before auto rudder coordination was enabled by default. It could be overridden using hard rudder input but wasn't necessary.
Amazing how many people have been coordinating their turns with their rudder pedals.
Now it states that auto rudder on, will auto coordinate and reduce crosswind effect on takeoff.
Not only is the irony of this placebo not lost on me, but may explain a lot of the instability issues people were complaining about over the last 12 months.
Many were convinced it wasn't auto coordinating because of a lag when turning. But they were wrong.
Lol.
Seems they have now tightened up the entire rudder/coordination issue.
Good times.
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I've since noticed that there is a keystroke that can toggle auto rudder on and off... which is useful for taking off and landing.
Activating auro rudder once off the ground gives us the coordinated turns, but can then be deactivated for "spectactular" crab landings... of which I am, of course, extremely proficient ... 🥴🤣🤣🤣
