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A380-omega autopilot problem

Designing a stable autopilot is one of the hardest things. Need help?

A380-omega autopilot problem

Postby KaleidoS » Tue Apr 02, 2019 12:58 am

Hello everybody, first of all i would like to introduce me. I'm Ricardo an electronic engineer from Argentina (sorry for my bad english) and im interested on a380-omega plane (nice cockpit on this one). I started using FG recently and i love it. I figured out that the autopilot and app system of this plane doesn't work well, it seems that PID needs a better tunning (doesn't align correctly and it makes sharp turns). I have knowledge about control systems so can help with that. I understand that omega no longer updates its aircraft so i think its a good idea if someone can continue with one of this good projects. I think it will take me some time to get used to the code, so if someone can give me some guide or help I would appreciate it a lot. Greetings and good flights!
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Re: A380-omega autopilot problem

Postby Octal450 » Tue Apr 02, 2019 4:56 am

PID tuning and control loop design is not just a simple thing, takes some knowledge and experience to do right, (as you probably know if you took control theory classes). Irregardless, I looked into this some years back:

Problem 1: A/P is poorly layed out, too much nasal interfearing in the loop, PIDs in places there should not be, bad integrators
Problem 2: Bad FBW stability, the FBW on this plane is really poor and does not work well. A/P commands this FBW, so in the end it will end up behaving odd (As you mention)

Essentially to fix this, the FlyByWire needs to be completely rewritten, and the a totally new A/P on top of it. But if someone is going through all that, the FDM needs attention, and there is tons of missing or wrong logic in the controls of the A/P and other aircraft systems that tie into it.

So unfortunately it is a big task. If someone wants to start, you may want to use my Airbus A330 FBW as a base.

PS: You're english is good!

Kind Regards,
Josh
Last edited by Octal450 on Thu Feb 15, 2024 8:21 am, edited 1 time in total.
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Re: A380-omega autopilot problem

Postby MalleusMaleficarum » Tue Oct 01, 2019 7:16 am

The A380 is a wonderful aircraft. it's unfortunate that the current one is unfinished or kinda broken. im learning nasal and took the liberty to add/fix some functions:
1. an 'autostart' menu function for lazy pilots.
2. a new autopilot control panel with butter smooth full autoland function.
3. stall and overspeed warnings.
4. other GPWS sounds.
5. a Garuda Indonesia livery.
6. various tiny bug fixes.
7. for even lazier pilots (like me!), i got carried away and added 'auto take off and go around' functions :)

here have a look at the result. it's not perfect but it works! :P
https://www.youtube.com/watch?v=L_CZiqvsy2I
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Re: A380-omega autopilot problem

Postby Octal450 » Tue Oct 01, 2019 7:32 am

@Malleus,
If you are going to install a 777 autopilot - instead I urge you to install IT-AUTOFLIGHT as I already have an Airbus setup using it that you can take inspiration from.
http://wiki.flightgear.org/IT-AUTOFLIGHT

But really the whole FDM and FlyByWire and most of the systems needs to be redone.

Kind Regards,
Josh
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Re: A380-omega autopilot problem

Postby MalleusMaleficarum » Tue Oct 01, 2019 7:58 am

@Octal,
i was just fiddling with the original codes for the autoland function since it always seem to be doing a nose dive on the runway :P and got carried away and ended up redoing all of the codes for that function. i know IT-AUTOFLIGHT is a lot more advanced that this one with different PID controller settings and all (the IDG aircrafts r still the most realistic in Flightgear). but yeah u r right. it does need a whole rework of the FDM and the FBW. i'll definitely check out the IT-AUTOFLIGHT codes to see how much work would be needed to incorporate it into this aircraft :)
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Re: A380-omega autopilot problem

Postby Octal450 » Tue Oct 01, 2019 4:13 pm

Hi,
If you check out the wiki article, there is a full install and tuning guide.

Thanks for compliments.

Kind Regards,
Josh
Skillset: JSBsim Flight Dynamics, Systems, Canvas, Autoflight/Control, Instrumentation, Animations
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Re: A380-omega autopilot problem

Postby vezza » Sat Oct 12, 2019 8:47 pm

@Malleus,

I've seen you are bringing back to life the A380-omega... is it possible to test it? Do you have a git repo?
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