Stupid AP crap needs testing

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bomber
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Re: Stupid AP crap needs testing

Postby bomber » Mon Aug 22, 2016 8:27 am

LesterBoffo wrote:I agree that the default AP has too quick a reaction time, but.. The forces on the aircraft's fuselage should be more than adequate to damp out a few phugoid cycles despite the trim over run. When at 33.000 feet and at level flight with the default AP off, see how many aircraft will damp their phugoid within a couple cycles when your joy stick is neutralized. The fuselage is a huge stability factor at 300+ knots. Both FG fdm's, if made at their very basest of coding do not have much if any fuselage damping.


The fuselage dampens ? I'm not sure it does.

Longitudinal damping is very much a product of the h-stab's decalage to the main wing, along with the increase/reduction in AoA on the h-stab caused by the rate of its rotation.

A problem I also see is that the trim fcs code in for example jsbsim doesn't really reflect what's happening in real life... I'm not saying it's wrong for every plane but that the mechanics of trim are different for a WWII plane to a fast fly by wire jet.... so which trim is being used ?

Simon
"If anyone ever tells you anything about an aeroplane which is so bloody complicated you can't understand it, take it from me - it's all balls" - R J Mitchell

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Side
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Re: Stupid AP crap needs testing

Postby Side » Mon Aug 22, 2016 10:47 am

it0uchpods wrote:Well I'm sick of the stupid slow nasal logic...
I'm moving alot of logic to XML.

@JWOCKY was once again right!
Putting all my logic in nasal was a GIANT FUCKING WASTE OF TIME.

So over the next few days, I will be completely rewriting my AP's logic, but not pid-controllers.

I need people willing to test please!!!!
717
MD88
MD90
A340s
KC137R
Choose a model, doesn't matter which, I would appreciate it alot!

I'll post here when it's ready to be tested.

Thanks,
Josh


I will test the 717 and I'll report

Side

Octal450
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Re: Stupid AP crap needs testing

Postby Octal450 » Mon Aug 22, 2016 3:03 pm

@side
Thanks!

Octal450
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Re: Stupid AP crap needs testing

Postby Octal450 » Mon Aug 22, 2016 3:04 pm

bomber wrote:A problem I also see is that the trim fcs code in for example jsbsim doesn't really reflect what's happening in real life... I'm not saying it's wrong for every plane but that the mechanics of trim are different for a WWII plane to a fast fly by wire jet.... so which trim is being used ?


My AP is designed for airliners only. It uses elevator, then uses the trim to central the elevator.

Josh

bomber
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Re: Stupid AP crap needs testing

Postby bomber » Mon Aug 22, 2016 5:05 pm

Do you mind posting up the trim code ?
"If anyone ever tells you anything about an aeroplane which is so bloody complicated you can't understand it, take it from me - it's all balls" - R J Mitchell

Octal450
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Re: Stupid AP crap needs testing

Postby Octal450 » Mon Aug 22, 2016 6:18 pm

its on GitHub.
see http://www.github.com/it0uchpods/IT-AUTOFLIGHT.git
see Systems/it-autoflight.xml lines 886 - 1014. The PITCH FILTER is driven by the pid-controllers in lines 799 - 884. There is a separate on for FLCH mode, since it needs a slower reaction.

If you have any questions let me know.

Josh

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IAHM-COL
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Re: Stupid AP crap needs testing

Postby IAHM-COL » Mon Aug 22, 2016 7:02 pm

it0uchpods wrote:its on GitHub.

see Systems/it-autoflight.xml lines 886 - 1014. The PITCH FILTER is driven by the pid-controllers in lines 799 - 884. There is a separate on for FLCH mode, since it needs a slower reaction.

Josh




Direct Link
https://github.com/it0uchpods/IT-AUTOFLIGHT/blob/master/Systems/autopilot-dlg.xml
https://github.com/it0uchpods/IT-AUTOFLIGHT/blob/master/Systems/it-autoflight.xml
https://raw.githubusercontent.com/IAHM-COL/gpg-pubkey/master/pubkey.asc

R.M.S.
If we gave everybody in the World free software today, but we failed to teach them about the four freedoms, five years from now, would they still have it?

Octal450
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Joined: Sun Oct 18, 2015 2:47 am

Re: Stupid AP crap needs testing

Postby Octal450 » Mon Aug 22, 2016 7:05 pm



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