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Space Shuttle - Bugfixes

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Re: Space Shuttle - Bugfixes

Postby Thorsten » Thu Jun 06, 2019 5:42 am

Now I suspect that in upward position, the roll attitude is body-y[0]? (wild guess), which then would explain why the Shuttle never rolls to correct attitude when starting with inclination=latitude, the dot product is independent on roll while the Shuttle is in upward position due to the vanishing of course-vector[0]. So this can only happen for inclination=latitude, which is what I do see.


The thing is that I've done more than a dozen launches in and around HST inclination last week - and without exception, they went fine.

So I concur with your error diagnosis - if you launch into a non-set course vector, then you'd observe what you do - but I don't see that happening in the first place. The code is set up to catch the badly posed problem, and it seems to do that for me.
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Re: Space Shuttle - Bugfixes

Postby eatdirt » Thu Jun 06, 2019 6:44 am

The thing is that I've done more than a dozen launches in and around HST inclination last week - and without exception, they went fine.


Arg, indeed, if you cannot reproduce, that's weird. The problem I have is only when --heading=90, and to be precise, I start fgfs with this:

fgfs --aircraft=SpaceShuttle-launch --prop:/mission/filename=hst.xml --lat=28.6274 --lon=-80.6209 --heading=90


So the AP is already set when I have a look at Launch Guidance and this is a situation in which the inc=28.47 in the mission file is < latitude, so it is exactly reset to inc=lat. Could someone test that command too?
I cannot believe I am alone blowing up with this, if yes I am out of clue :-/.

it actually aligns the tail fin with the desired azimuth by maximizing the dot product


I may not be competent enough to fully understand the stage1 part of the AP coding, but it looks like, in that precise situation, the stage1-roll-error which is minimized is given by a dot product, not by 1-dotproduct. So, there is a degeneracy plane in that very precise situation no?
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Re: Space Shuttle - Bugfixes

Postby eatdirt » Sun Jun 16, 2019 10:06 pm

Hi there,
spotted a "mini" bug in doing RTLS, during OPS602(R), entering some SPEC XX PRO leads to the expected page, but hitting RESUME afterwards does not give back the main OPS602 page, just a black one. After transitioning to OPS603 everything is back to normal, so this issue does not last long, just during OPS602. This is for 2019.2.0.

Image

Cheers,
Chris.
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Re: Space Shuttle - Bugfixes

Postby GinGin » Thu Jun 20, 2019 11:06 am

Well Spotted, I remember that one also
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Mon Jun 24, 2019 11:30 am

Gentlemen, when something weird happens, please check the log for error messages (I tend to assume there are none if none are reported). The no resume from 602 error is not actually a no resume error, it is a simple Nasal crash due to a typo.

I've discovered another error where saved settings are only partially recovered - which also runs into a Nasal error which causes the resume procedure to terminate halfway (which brings you into the correct position, but the orbital target rather not).

These things are trivial to hunt down if I know the error message, but if it's triggered by some special situation like in the save/resume case, I may never be able to find it unless by accident.
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Re: Space Shuttle - Bugfixes

Postby eatdirt » Mon Jun 24, 2019 9:02 pm

Yes, sorry Thorsten, I remember seeing the message on the console... Well done for the save/resume, I had that one too!!!

Taking about the messages in the console, with 2019.2.0 devel, I get some warnings like this:

In file ...org.flightgear.fgaddon.trunk/Aircraft/SpaceShuttle/Systems/rcs_control.xml: line 766
<sum> only has one argument which makes it a no-op.
Its argument will be evaluated but <sum> will not be applied to the result.


I have assumed they're unimportant, but I can list them all here if necessary.

Cheers.
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Tue Jun 25, 2019 6:38 am

I have assumed they're unimportant, but I can list them all here if necessary.


They're harmless, but worth hunting to clean up the log.
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Tue Jun 25, 2019 8:49 am

But... I suspect this scalar product is "body-y[]. course-vector[]". In launches with inclination <= latitude (If I got it right, this situation lands back to inclination=latitude) , in the nasal console, I can see that course-vector[0]=10^(-17), while all along stage1 ascent the stage1-couse-error and the stage1-roll-cmd remain ridiculously small.


So, taking a look at that one.

There's actually nothing *really* wrong here, the underlying issue is that orienting the Shuttle exactly 180 deg to the desired launch azimuth is... an unstable equilibrium point. The AP could turn left or right, butat exactly 180 deg it doesn't know which and requires the situation to become unstable due to a random fluctuation - unfortunately by the time this happens guidance stage 1 is over. If you disable limit checks, you can see the AP recover the proper course and attitude later, but the resulting set of maneuvers is of course not survivable.

Starting with an initial orientation of 91 degrees on the other hand is quite enough to initialize a proper roll.

Note however that for such a long (180 deg) roll, you need to modify the throttling program to throttle down earlier, otherwise you'll still get into trouble.
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Re: Space Shuttle - Bugfixes

Postby GinGin » Tue Jun 25, 2019 10:50 am

Great, thanks Thorsten
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Re: Space Shuttle - Bugfixes

Postby eatdirt » Tue Jun 25, 2019 7:41 pm

Here we go, this is for the last snapshot of fgspaceshuttle, with 2019.2.0 (snapshot a month ago or so)


Code: Select all
...SpaceShuttle/Systems/rcs_control.xml: line 766
<sum> only has one argument which makes it a no-op.
Its argument will be evaluated but <sum> will not be applied to the result.

...SpaceShuttle/Systems/rcs_control.xml: line 789
<sum> only has one argument which makes it a no-op.
Its argument will be evaluated but <sum> will not be applied to the result.

...SpaceShuttle/Systems/rcs_control.xml: line 812
<sum> only has one argument which makes it a no-op.
Its argument will be evaluated but <sum> will not be applied to the result.

...SpaceShuttle/Systems/computations.xml: line 695
<max> only has one argument which makes it a no-op.
Its argument will be evaluated but <max> will not be applied to the result.

...SpaceShuttle/Systems/computations.xml: line 728
<max> only has one argument which makes it a no-op.
Its argument will be evaluated but <max> will not be applied to the result.

...SpaceShuttle/Systems/computations.xml: line 759
<max> only has one argument which makes it a no-op.
Its argument will be evaluated but <max> will not be applied to the result.

...SpaceShuttle/Systems/autopilot.xml: line 3415
<product> only has one argument which makes it a no-op.
Its argument will be evaluated but <product> will not be applied to the result.

...SpaceShuttle/shuttle.xml: line 3054
<product> only has one argument which makes it a no-op.
Its argument will be evaluated but <product> will not be applied to the result.


and a warning on OSG:

Code: Select all
[WARN]:OSG        Warning: Material::setShininess() of 200 is above permitted maximum, clamping to 128.
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Re: Space Shuttle - Bugfixes

Postby eatdirt » Thu Jul 11, 2019 8:44 pm

Hi there,
I've just encountered a very weird sound issue with latest fg-next branch snapshot and latest shuttle. I am loosing the cockpit sound of the SSME just before SRB separation, but only the SSME sound. All other sounds in the cockpit are fine, announcements, clicks on buttons. Later on, I also do not hear the external tank separation sound neither. I'll report the problem on the dev-list, but let me know if you think it is a stupid mistake from my side.
Thanks,
Cheers,
Chris.
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Fri Jul 12, 2019 6:14 am

It would sound like a core regression, because I've not experienced that with any older FG version and not changed any sound in the Shuttle code.
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Re: Space Shuttle - Bugfixes

Postby eatdirt » Fri Jul 12, 2019 12:28 pm

Thanks for the answer Thorsten. Digged a bit more, that's a local issue, I have it also with official 2018.3.2 and SpaceShuttle from the launcher. Just updated my system last week to latest distro version, with kernel 5.1.14. Most likely it is a bug in libasound, a rebuild of fg does not fix it. Will be tough to debug, sorry about the noise!
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Re: Space Shuttle - Bugfixes

Postby legoboyvdlp » Fri Jul 12, 2019 7:04 pm

On the latest Shuttle -
Code: Select all
ERROR: Cannot add listener to tied property /fdm[0]/jsbsim[0]/gear[0]/gear-pos-norm[0]


I think this one is local to the Shuttle as I don't see it elsewhere?

Also, as I launch every so often the ET goes dark (as if a cloud is over the sun or there is a shadow) momentarily then returns light again - is that expected?
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Re: Space Shuttle - Bugfixes

Postby GinGin » Tue Aug 20, 2019 4:49 pm

I found back a paper where I noted some small things ( not real bugs or whatsoever, just minor discrepancies here and there)
I just put that here to not forget it again.
A lot of things are really nitpicking, so don't blame me ahah.
Just want to put that somewhere






1) OMS to RCS dump Time


Based on that document ( RTLS dump for 83 % of OMS propellant),

Image


We should have a dump with OMS only of 555 seconds, which we have :

Image


However, with interconnection, we should have 200 s ish, and we have a much smaller time ( 110 seconds, confirmed with many tests)

Image




2)HAC Size in Spec 50


I think that the closer we are from the HAC , the bigger it is ( like a zoom in stuff)
Here from SSMS 2007 ( same in SSU)

Image


Image


And a real one

Image





3)Size of IDP number and dimension of Red/Yellow IDP selection line

I remarked ( especially on the last picture) that the size of the IDP number ( 1 ) is much bigger and line is longer than what we have.
I can try to change it, I don't know if it has to been changed in every dps nasal page, or if is a generic thing for all IDP basic settings ?





4) Prelaunch PFD datas

In MM 101, before SSME ignitions, there are no values on the PFD except for the ADI

Image


Is it possible to put that stuff you made in MM 101 with NAV Air Data selected before ignition ?

Image



5) MM 304/ 305//// 602/ 603 Dap mode on PFD

A small thing I noticed recently.
In the Major Mode above ( basically entry stuff), DAP on PFD is a bit different, showing Pitch and Roll/Yaw in a separated manner ( DAP in other MM)
I think it is coming from the fact that except for entry, when we swith one mode in manual ( R/Y or Pitch, the both go into manual, and for entry, we can select one in manual and the other one in auto)

Image


Image
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