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Re: IDG PA28 Development

Postby Robertfm » Sat Sep 21, 2019 10:22 pm

I'll do that tomorrow. It's passed my bed time.
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Re: IDG PA28 Development

Postby Robertfm » Sun Sep 22, 2019 10:59 am

I've sent a video via Google Drive well at least I think I have. You will see how when APR becomes active the plane turns away. As I say no idea what it going wrong.
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Re: IDG PA28 Development

Postby wkitty42 » Sun Sep 22, 2019 3:09 pm

Octal450 wrote in Sat Sep 21, 2019 7:08 pm:That's not the case at all wkitty, I check for these things always. There is nothing wrong with the brakes.

someone else suggested it as possibly being the problem... i just tried to clarify that to the reporter of the problem... it may or may not be the actual problem, though... that's someone else's problem to find ;)
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Re: IDG PA28 Development

Postby Robertfm » Sun Sep 22, 2019 3:49 pm

I followed Josh's advice using just small amount of right rudder and the plane didn't drift off. A lot easier though to activate Parking brake as soon as you start the plane just in case, whilst you doing other things.
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Re: IDG PA28 Development

Postby Octal450 » Sun Sep 22, 2019 4:25 pm

Yes... IRL if you put full pedal by the way it would slam the airplane away from the runway to the right - but JSBsim is weird with that and the wheels slide instead.

@wkitty no worries

@Robert I will check out your video and reply shortly.

Kind Regards,
Josh
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Re: IDG PA28 Development

Postby Octal450 » Sun Sep 22, 2019 4:34 pm

Hi Robert,
the Autopilot is functioning exactly as designed here. I will explain here something:

The NAV mode has 2 possible options - NAV and NAV GPSS. NAV itself follows NAV radio, either NAV1 or 2, whichever is selected on the panel. (by default NAV1). NAV GPSS follows the route manager. APR is not a separate mode, it simply increases the control gain in the deviation control loop. When you press APR, the GPSS mode will kick off. That is because unlike the S-TEC 55, the 55X talks directly with the GPS (Route Manager for now) and thus GPSS commands do not go through the NAV deviation system. APR is only used for ILS/VOR approaches, not for RNAV approaches - those stay in NAV GPSS. When GPSS kicked off, NAV went to seek the radial follow again. In your video: the COURSE on the HSI was set to roughly 050, and the maximum deflection is 45 degrees from course. Thus, the aircraft went on an intercept heading to 050, which since you were to the right of the signal, was roughly 005. The aircraft will remain on that heading until the HSI's deviation point begins to move towards the center. Once it hits a certain amount closer to center (depends on how fast the needle is centering) the system will turn onto a course near 050, and then after roughly 30 seconds or less establish wind correction. The system also modifies the gains and maximum turn rate as the capture occurs, as written on Section 3.1.2 (page 3-3) of the POH I linked on dropbox.

Hence the system acted exactly as it should have. If you are using the Route Manager waypoints for approach, you do not use APR mode, just stay on NAV GPSS.

Hope that clears it up. If you'd like me to make a demo video on how to perform an ILS or GPSS approach with the S-TEC, I can do that.

Kind Regards,
Josh
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Re: IDG PA28 Development

Postby Robertfm » Sun Sep 22, 2019 8:27 pm

A video would be helpful but let me see if I get this right. If I am using Route Manager Nav GPSS as I was and Nav 1 Localiser for airport I just let the plane follow that route and do nothing else. How then do I lock on to Glide slope if I don't press a button. In the other AP you click on Nav 1 & CDI when in range.
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Re: IDG PA28 Development

Postby Octal450 » Sun Sep 22, 2019 10:02 pm

Well, it was because your course was set wrong. You didn't setup the course on the HSI correctly thus the A/P thinks the localizer is somewhere else. Keep in mind the Nav 1 and CDI thing in the generic DOES NOT EXIST in real life - there is no such "instantly follow LOC signal" - keep in mind that mode also follows FG's auto-nav thing to the localizer.

The real S-TEC and most GA autopilots only know 2 things. Course heading set, current heading, and LOC needle deviation. That is all it knows. So you must set course correctly or else it can't work. Anyways I will record a video soon for you showing the entire process.

Kind Regards,
Josh
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Re: IDG PA28 Development

Postby Robertfm » Mon Sep 23, 2019 5:35 pm

I look forward to the video as I have read well over a dozen tutorials and 3 or 4 videos . Have entered the heading into the HSI that is shown on the FGMP for each airport and the correct frequency in Nav 1 and still cannot get it to work. There has to be a bit I am not getting.
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Re: IDG PA28 Development

Postby Johan G » Mon Sep 23, 2019 5:56 pm

Octal450 wrote in Sat Sep 21, 2019 7:08 pm:Johan - why are you telling non-developer users to poke around randomly at the property tree? That is a BAD idea. [...] Non-developers should stay OUT of the property tree unless they are being asked to view/set a specific value as directed by IDG Team Member for debugging.

Just to have a look and see if per chance one of the brakes would be slightly applied. If that was the case the cause could perhaps be input devices or bindings. Messing around changing values of properties at random was not what I had in mind. :wink:
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Re: IDG PA28 Development

Postby Octal450 » Mon Sep 23, 2019 7:34 pm

Hi Robert,


Please excuse the erratic inputs at the end from me - forgot to setup joystick properly before filming.

Hi Johan,
OK.

Kind Regards,
Josh
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Re: IDG PA28 Development

Postby Robertfm » Mon Sep 23, 2019 7:54 pm

Thanks very much have watched it once and things are clearer. I will watch it a few times and if I have any further questions I will get back to you. What immediately comes to mind is whether this will work if I do not add an additional waypoint other than those already in Route Manager.

Well I followed your instructions and the ILS approach worked perfectly. Thank you so much. There was however just one thing When I pressed the HDG ( on the panel) & held it as you suggested as a short cut on pressing the Nav button HDG didn't illuminate and the Nav & APT were fixed and plane started to turn. I switched back to GPSS and the plane returned to route and as I said manually activating Nav/Apt worked fine.

As I said I have read numerous explanations and nothing seemed to work for me. Your explanation was crystal clear even for an oldie like me.

One last question would the heading work by simply adding a zero as the headings on the map seemed to be close to that. IE runway 23 was 232 runway 05 was 055 so it seems to be based on them.
Last edited by Robertfm on Mon Sep 23, 2019 9:21 pm, edited 1 time in total.
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Re: IDG PA28 Development

Postby Octal450 » Mon Sep 23, 2019 9:17 pm

It does not matter at all. You can do the same in HDG mode instead of NAV GPSS with no route programmed whatsoever then switch to NAV APR
Just make sure you are below the G/S (indicator up from center) when you intercept

Kind Regards,
Josh
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Re: IDG PA28 Development

Postby Robertfm » Tue Sep 24, 2019 2:36 pm

If an airport is not showing ILS will it not capture GS. I ask this because I've flown to EIDL (Donegal) . Runway 21 has a localiser/Nav1 and on the FG flight map it shows runway heading. I inputted both and when I got to capture point it captured as it should. I was at 2400ft. When I got where GS should have activated and started descent nothing happened. I pressed ALT as per instructions to force GS but still nothing.I had to descend manually. So I'm confused.
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Re: IDG PA28 Development

Postby legoboyvdlp » Tue Sep 24, 2019 3:33 pm

The answer to that would be that Donegal doesn't have an ILS.
http://iaip.iaa.ie/iaip/Published%20Fil ... 4-3_en.pdf
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