IT-AUTOFLIGHT V4.0.9 Beta

[Octal450]

Ty

Kind Regards,
Josh

[Octal450]

Update... someone reported a bug to me in the blank modes, sorry. I have fixed the issue and re-released ITAF 4.0.7. I also took this moment to squeeze in the Wing Level mode. It is not in the GUI, but available to aircraft developers who need it (set lat input to 6).

Code: Select all

V4.0.7:
[Control Loop]
* Added: New rate based FLCH (speed on pitch) controller
* Added: Ability to use a third NAV radio
* Added: Wings Level mode
* Fixed: If all APs and FDs are off, and the autopilot is engaged in V/S mode, the pitch might jerk
* Fixed: Flare law shallowing up too early and floating
* Fixed: Really slow response in some situations
* Fixed: Strange bug with glideslope
* Changed: Flight Director Pitch now outputs in degrees (in Canvas, you can just translate it the same as pitch scale)

[Logic]
* Added: Ability to define when APs and A/THR are available
* Added: APs and A/THR trips off if respective system is unavailable
* Added: Ability to set blank mode
* Added: Ability to start with flight directors on by default
* Added: Armed modes disarm if they become unavailable
* Added: Ability to use a third NAV radio
* Added: Built in VS/FPA switching logic
* Added: Wings Level mode
* Fixed: Bad handling of radio selection
* Fixed: LOC capturing too early on shallow intercept and increasing intercept angle
* Fixed: Flare engagement

[GUI]
* Added: NAV source toggles for all 3 radios


https://github.com/Octal450/IT-AUTOFLIG ... /tag/4.0.7

Kind Regards,
Josh

[Octal450]

Hi,
I've added a new speed on pitch control loop for the autopilot.
It no longer uses an integrator at all - meaning no more chasing the FD bar, and more stable operation overall!

It is in testing in the MD-11, A320-family, and MD-80. I will be adding it into the 4.0.8 Beta shortly. For years the fact that an integrator was needed was a hurdle for speed on pitch to be stable, but the latest control scheme I've come up with is in fact more stable and accurate, without an integrator. Can you believe that?

Kind Regards,
Josh

[dom_vc10]

Yes I can, if you wrote it You're doing some excellent stuff here most of it goes over my head but I know I am benefitting from it so thanks!

[TheEagle]

Do you think the same would be possible for other modes ? If so it could also be used in other aircraft, independent of IT-Autoflight (for example my 210's autopilot has a pretty slow reaction, in order to not oscillate).

[Octal450]

Hi,
updated the loop slightly to improve some stability in weather.

@dom_vc10, thanks friend I appreciate your kind words

@TheEagle
Already ITAF does not use any integrators for any FD modes. Only the autopilot's taking the FD course and flying it uses integrators. All FD paths in lateral or vertical are calculated by absolute function. Integrators are bad for flight directors. Speed on pitch was the last mode using an integrator.

If your AP is bad, then seems you should instead replace with one of my reworked GA systems. S-TEC 55X or also the NEW KAP140 (w/ Sascha + benih + others) have proper control loops that fly stably.

Otherwise if you need some other AP, you can ask me about it and I might be able to help you in something.

Kind Regards,
Josh

[TheEagle]

Thank you very much Josh, my 210 uses some old ARC autopilots, not KAP140 or STEC55X (or it does, but only as a retrofit), so I'll definitely come back to your offer at some point !

[Octal450]

Gotcha.
Let me know if you want any work done

Kind Regards,
Josh

[Octal450]

I have updated the design again. It now is a little smoother and works better in turbulence. It is a careful balancing act to have enough filtering to work with noisy airspeed inputs, but not too much where it becomes laggy and overshoot-y (especially with FD manually flying).

Kind Regards,
Josh

[Octal450]

Hi,
A few fixes have been made over the last months and now I am sent final V4.0.8.

The final changelog:
V4.0.8:
[Control Loop]
* Added: Internal control drivers for overridable yoke (New config required)
* Added: New speed on pitch control loop without integrator
* Added: Ability to not drive throttle directly with autothrottle
* Added: CWS interrupt ability
* Added: More flexible bank limit system with overrides (New config required)
* Added: Ability to adjust FLCH acceleration/deceleration rate (New config required)
* Added: Improved flight director pitch calculation
* Added: Ability to adjust flight director pitch bar when on the ground in takeoff mode
* Added: T/O roll mode now includes ability to capture current heading
* Added: Wing level mode replaced with basic roll hold
* Changed: Tweaked rate scheme slightly

[Logic]
* Added: Ability to not drive throttle directly with autothrottle
* Added: More flexible bank limit system with overrides (New config required)
* Added: T/O roll mode now includes ability to capture current heading
* Added: Wing level mode replaced with basic roll hold
* Fixed: Bad behavior when switching on and off true course
* Changed: Renamed reduc-agl-ft to accel-ft
* Changed: Renamed togaspd to toga-spd
* Changed: Renamed lat-agl-ft to lnav-ft

Kind Regards,
Josh

[Octal450]

Work on 4.0.9 has started.
So far, a couple of things have been added.

- A basic pitch angle hold mode (like the basic roll hold mode, this is not accessible from the default dialog as most airlines don't use it, but the mode is now there for those who want it. vert = 8 )
- A third autopilot (747/757/767 support)
- Ability to disable the ground takeoff mode locking
- Minor fixes

Got a bunch of nice things coming, so stay tuned to the dev branch.

Kind Regards,
Josh

[unhappytroll]

will it be working with 707?

[Octal450]

If installed onto it, yes. But ITAF simulates more modern systems, so likely would not be drop in realism.

Kind Regards,
Josh

[unhappytroll]

well, spend two hours experimenting, without discernible result. probably doing something wrong, ofc.

[Octal450]

I can't help if you don't provide more info, unfortunately.

See the KC-137R (modified 707) if you want an example of how it is to be installed. The 137R also has a ITAF compatible head unit.

Kind Regards,
Josh