1 hour ago, DAD said:

Only one can be installed. Make your choice. Until FBW merges the cfbw into their regular branch

thanks I'll give it a try tonight 

How do I install the latest version with the custom fbw system?

Get it from here:

https://github.com/flybywiresim/a32nx/tree/fbw
😉

25 minutes ago, David Roch said:

Get it from here:

https://github.com/flybywiresim/a32nx/tree/fbw
😉

direct link for the custom fbw is https://flybywiresim-packages.nyc3.cdn.digitaloceanspaces.com/vmaster-cfbw/A32NX-master-cfbw.zip. not sure whether the link always remains the same

26 minutes ago, DAD said:

direct link for the custom fbw is https://flybywiresim-packages.nyc3.cdn.digitaloceanspaces.com/vmaster-cfbw/A32NX-master-cfbw.zip. not sure whether the link always remains the same

That's what I am wondering as well. I'm not sure if that direct link is to the latest version or an older build.

1 minute ago, captain420 said:

That's what I am wondering as well. I'm not sure if that direct link is to the latest version or an older build.

Maybe @AGuther or someone from the FBW team can shed some light on this. But since the other download links for the „normal“ mods remain also the same I would expect this is the case also for the cfbw. Not sure though how often it is actually update. Just downloaded it again since before msfs did not even load with the cfbw mod. I hope there may be an update at any time which cures this issue

4 minutes ago, captain420 said:

That's what I am wondering as well. I'm not sure if that direct link is to the latest version or an older build.

last commit was 12 hours ago which is here. It means sort of up to date, I think Andreas needs to update the branch manually every day or every few days. 

That direct link is automatically updated by our CI/CD system when new commits are made to the FBW branch.

Just now, IcemanFBW said:

That direct link is automatically updated by our CI/CD system when new commits are made to the FBW branch.

Good to know. Thanks for that quick answer

4 minutes ago, IcemanFBW said:

That direct link is automatically updated by our CI/CD system when new commits are made to the FBW branch.

Good to know, however I was wondering, now that branch needs to be manually rebased, couldn't be better to have an auto-sync or auto rebase whenever there are changes added to the master branch? 

10 minutes ago, IcemanFBW said:

That direct link is automatically updated by our CI/CD system when new commits are made to the FBW branch.

Thanks for the quick response and confirmation! 🙂

10 minutes ago, captain420 said:

Thanks for the quick response and confirmation! 🙂

Eben better. It indeed loads again on my end. Just started quick flight from EDDT to EKCH. Climbing to 8000 now. All fine so far

12 hours ago, AGuther said:

Hello,

Airbus does not implement a pure load factor demand (nz) in pitch normal law. It's a mix of pitch rate and load demand and is therefore similar to a so called C* control (but not totally equal because Airbus is scheduling the mixture of load demand and pitch rate; pure C* uses always factor of 12.4). For the moment the custom fly-by-wire is also using the factor 12.4. Therefore it produces too low pitch rate / load factor in different speeds. This will be tuned and improved over time (it's a big effort to get this on the spot; testing full fbw cg, neutral cg, full aft cg and at different speeds).

Having said that, don't expect that the FPA to be on rails...it's very good but in reality it's also not on rails. I've seen that with my own eyes years ago when there was still the option to get into cockpit during flight. The pilots deactivated the AP in cruise and guess...the aircraft began very very slowly to climb...

The custom fly-by-wire is in terms of real aircraft performance far from perfect and this will take time to get it better and better. That stuff is really not easy. Still it's a big improvement to the default A320.

I hope this answers you question.

Best,
Andreas

Many thanks Andreas, great post!

Your fbw approach sounds very comprehensive indeed. May I ask some things more?

- Out of curiosity, what is the information source for the Airbus FBW system? E.g. where have you found this 12.4 factor?

- Is the speed dependent blend between pitch rate and load demand implemented? Above 210kts it should be G only, right?

- Looking in code, the feedback to the sim seems to be just setting the three elevator/rudder/aileron axes variables. How is it handled, that the control input by the user does not interfere with your calculated positions? 

- How do you tune the controller? I am interested because deriving the PID factors (yes, such a fbw system has all the ingrediences of an autopilot!) automatically was exactly what I did in 2002. I used a method similar to the one described here. By measuring a bode plot of the control line ("Reglerstrecke", which meant simply letting oscilate the pitch of the aircraft from maybe 0.01HZ up to the point where the phase of the FPA response lagged more than 135°) I was able to get the PID factors easily and consistently.

Regards,
Martin

 

Edited December 11, 20205 yr by mrueedi

6 hours ago, mrueedi said:

Many thanks Andreas, great post!

Your fbw approach sounds very comprehensive indeed. May I ask some things more?

- Out of curiosity, what is the information source for the Airbus FBW system? E.g. where have you found this 12.4 factor?

- Is the speed dependent blend between pitch rate and load demand implemented? Above 210kts it should be G only, right?

- Looking in code, the feedback to the sim seems to be just setting the three elevator/rudder/aileron axes variables. How is it handled, that the control input by the user does not interfere with your calculated positions? 

- How do you tune the controller? I am interested because deriving the PID factors (yes, such a fbw system has all the ingrediences of an autopilot!) automatically was exactly what I did in 2002. I used a method similar to the one described here. By measuring a bode plot of the control line ("Reglerstrecke", which meant simply letting oscilate the pitch of the aircraft from maybe 0.01HZ up to the point where the phase of the FPA response lagged more than 135°) I was able to get the PID factors easily and consistently.

Regards,
Martin

 

Hello,

the factor 12.4 can be found from various sources that deal about flight control for aircrafts in real life, it‘s based on the theory that pilots naturally use pitch rate on slower speeds and load demand on higher speed. The speed where this changes was said to be 400 ft/s, this is the driver for the 12.4. I can recommend the book „Rudolf Brockhaus - Flugregelung“. There are also some papers that deal about that. I know that the law for pitch is at the moment not like it „should“ be, but from the tests I‘ve made it was still the best up to now. There is anyhow now way to get the info how Airbus implemented it, so...it keeps to be assumption in any case.

The blend is implemented in the sense of C*, but not specifically on 210 kts. I‘ve seen this value multiple times, but still I‘m lacking a reference. Do you have one for that? It would be also good to have some info what pitch rates / load demands an Airbus will achieve in real life...I‘ve heard something about 5°/s on slower speeds, but well, reference is not there and most pilots only can give you a „gut feeling“ if it‘s right.

I did some experiments with MATLAB to discover the transfer function of pitch, but yet it was not helping me that much. I will have a look on your reference maybe that brings me forward. I think it will end up with scheduling the parameters for different states like speed, config, center of gravity.

For the controls: it’s done by using the SDK function to mask events. So the sim does not get them.

So it seems you have also a lot experience on that topic...I‘m happy to get help where I can. I‘m doing everything in my free time beside full time job and family...and that stuff takes a lot of time...

Best,
Andreas

Edited December 11, 20205 yr by AGuther

Sounds like a great idea if you guys get in touch with each other. Anyways, thanks a lot for all the effort that goes into the A32NX!