Smoothing out the autopilot
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Is there any way to stop the autopilot from nosing down every time you engage it?
Example…straight and level with AP on. Hold paddle to gain height then let the FPM settle at 0 deg.
Let go of paddle and AP noses down to get level again.
I understand the AP is accurate based on real world behaviour but it is a little annoying.
edit…maybe it’s trying to match the original speed as well as alt?
Thanks.
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I actually use the paddle to smoothen. Not sure if it’s realistic, but it helps prevent the bouncing.
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(assume we’re talking about altitude-hold mode)
Remember there’s some lag on the fpm marker … fly it steady at the zero-vvi for a second before releasing the paddle. Otherwise there will be some overshoot and wobble as it converges back to target altitude.
Why? Probably because of P/I/D control loop. https://en.wikipedia.org/wiki/PID_controller
This is interesting tech-history to learn about … if you ever wondered how a tiny sidewinder missile could fly a lead-pursuit track to a target (in 1950!) or how cruise control in your car worked, long before the age of digital microprocessors… it’s the magic of analog P/I/D control loops.
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I guess this is better suited in technical support
Can you explain a bit more? I am not sure to understand what you’re doing and the effects you are expecting…
Cheers
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I guess this is better suited in technical support
Can you explain a bit more? I am not sure to understand what you’re doing and the effects you are expecting…
Cheers
AP on, alt hold and stpt
Level flight.
Pull paddle and pitch up to gain height.
Level off then release paddle.
Nose goes down, loses height then levels off.To me it seems like the AP is obsessed with nosing down after you engage it.
I guess it just wants more speed?
Thanks
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I guess this is an area I am not really knowledgeable on the AP but I don’t think you can compare it to a liner grade AP.
I guess a couple feet down is within acceptable parameters for this type of AP PID…I’ll leave the experts talking.
Cheers
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This AP has no integrator to reduce the residual error
I could make one of course but the real has none so ….
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I always wonder about things like that. No integrator for the autopilot, no integrator on the roll channel to deal with asymmetries. The latter may be down to complexity at the time, as the Rafale and Typhoon I believe have such functions now.
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I’m not suggestinbg the AP isn’t accurate, I’m just wondering how to fly in such a way that it doesn’t nose down as much.
I’ve read a few real pilot stories that the AP isn’t great.
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As far as I can tell, quickly switching from O degree att held level flight to alt hold mode causes some nose down.