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Space Shuttle - Bugfixes

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Re: Space Shuttle - Bugfixes

Postby GinGin » Sun Feb 21, 2021 6:00 pm

Was on manual throttle at MECO, reduced throttle, the engines went off in external views, but not everywhere else! MPS pressure chamber gauges in the cockpit were still showing burn, engine buttons were showing ON, and MECO was not detected


That is more a visual thing, the flames not matching the minimum SSME thrust commanded. Do you remember what were showing the MPS gauges inside the cockpit ( a value below 67 % ?)

You cant shutdown the engines by going to minimum thrust ( it will show normally 67 %) . You have to press the MPS pushbuttons to stop them in manual throttle in the logic coded.



switched to NO Y-JET and the Shuttle started spinning like hell,


Do you remember the Relative speed, altitude ?


doing only bug fixing for targeting a release?


That's mainly what we are doing I think.
And we also need to identify if the bugs reported where there also before ( by testing something that sounds weird in the stable branch for example)
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Sun Feb 21, 2021 6:11 pm

Anyway, we could also make a freeze of the devel branch (in another branch for instance), test it, and doing only bug fixing for targeting a release?


That is the plan. My current commits are mainly adding benchmark tests (scenarios), fixing small bugs and suppressing errors which trigger on init and are just confusing. It just seems to emerge that the FDM / display changes have a rather profound effect - things need to be re-tuned etc,

I guess the main issue is - we all have habits. And we test inside our habits, so we implicitly assume some things. But someone else has different habits. For instance, it never occurred to me before @eatdirt tried the really elliptic orbit with multiple aerobraking phases that we'd need logic to get out of the atmosphere during the entry phase.

I'm doing a stab in the dark here, but I frequently use the option to init only three displays when I need to re-start the simulation frequently - that restricts operations quite a bit and displays which would 'usually' be open simply are not (for instance, I might not have an PFD open at all).

So the test case that works perfectly well for one person simply can do weird things for another person because of the different habits. I remember the weird case of the fuel cell purge that worked fine for me (because I always tested in the GUI) - but it didn't work using the 3d-model buttons - because of a subtle issue with one of the bindings.

Which is why we really need to get to the bottom of the oddities which happen now, because... the changes to the FDM are good, but affect things in a lot of places.

Maybe the manual throttle creates a condition to escape the MECO logic?


Yes, MECO is only commanded when under auto-throttle - though you have the cutoff pushbuttons for that purpose... I'm not sure whether this is the real behavior or whether it's a relic of the times when you could simply blast off with the rocket as you liked (as long as the propellant lasted)...

But eventually, when TAEM came, all pitch/roll controls were frozen. Unless we have coded damages due to funny -G, we could have some transiting logic at TAEM that get skipped if NO Y-JET is selected?


Strange that you didn't get destroyed, probably we simply don't check for negative g, but the frozen controls might be actuator stall - usually a highly irregular entry gets you there.

***

Okay, I have two new ones - starting an APU seems to trigger an APU underspeed alarm while it spins up - this seems excessive and we need to suppress that I guess, we can't worry people with alarms triggering all the time...

And - long-standing issue - the Aerojet DAP is very good at holding zero beta, but it leads to an undamped yaw oscillation with no chance to fix this when not engaged at small beta (I lost another Shuttle as I tried to work my way from a de-orbit burn to an entry) - so I guess this eventually needs to be addressed as well.
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Re: Space Shuttle - Bugfixes

Postby wlbragg » Sun Feb 21, 2021 7:31 pm

Thorsten,

Sounds/soundfile.wav maps to the fgdata sound files for sure.
Aircraft/SpaceShuttle/Sounds/soundfile.wav maps to the local Shuttle sound files for sure.

Do you know if Sounds/soundfile.wav also will map to the local Shuttle sound files? I don't remember, but It must because we have a bunch of local sound files that use that path and if it doesn't work that way then they shouldn't be working.

The only thing I read was "This defined the path to the sound file. The path is relative to the FlightGear root directory but could be specified absolute."

I want to make this consistent and remove any possibility of future sound additions getting screwed up by mapping all sounds using Sounds/soundfile.wav.
I guess the only reason you might want the distinction would be to identify the location of the sound file.
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Re: Space Shuttle - Bugfixes

Postby wlbragg » Sun Feb 21, 2021 7:42 pm

I just pushed a change, so anyone currently working, remember to pull and merge.
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Re: Space Shuttle - Bugfixes

Postby eatdirt » Sun Feb 21, 2021 10:43 pm

the frozen controls might be actuator stall - usually a highly irregular entry gets you there.

Yes, MECO is only commanded when under auto-throttle


All right, all that makes sense, thanks!

That is more a visual thing, the flames not matching the minimum SSME thrust commanded. Do you remember what were showing the MPS gauges inside the cockpit ( a value below 67 % ?)


Yes, I suspect that could be just the visuals, the gauge were are 67%, throttle min from throttle min joystick

Do you remember the Relative speed, altitude ?

Above mach 13 for sure, and I clearly did not engage in a perfect position as I was on CSS, certainly drifting the time to look for the button. I'll retest all this in more nominal situations!
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Mon Feb 22, 2021 6:57 am

Do you know if Sounds/soundfile.wav also will map to the local Shuttle sound files?


I don't actually know, and things have historically had a way of being broken core-side if they relied on auto path-completion. There's also the complication that with auto-completion and identical filename, you're referencing an object you didn't intend (I have lost counts of how many times I've edited an effect file to wonder why the in-sim visuals never changed, to discover 20 minutes later that a different file with the same name was being used by FG).

So my policy has always been to be rather explicit and write the namespace or the explicit path where I want to look for something just to be sure. But I'll not hold anyone to that.

Yes, I suspect that could be just the visuals, the gauge were are 67%, throttle min from throttle min joystick


That should be quite fixable, I'll have a look.

Edit: Hm... all animations and effects use the engine thrust as reference, so the visual should only be off if you have no thrust on the engine... At least the code looks correct, needs to be tested in-situ...
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Re: Space Shuttle - Bugfixes

Postby eatdirt » Mon Feb 22, 2021 7:35 am

Edit: Hm... all animations and effects use the engine thrust as reference, so the visual should only be off if you have no thrust on the engine... At least the code looks correct, needs to be tested in-situ...


All right, thanks, I'll recheck this carefully to see what is going on! (it was during a failure scenario though, with 1 engine out, I've just check and it seems to work fine in the nominal situation).
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Re: Space Shuttle - Bugfixes

Postby GinGin » Mon Feb 22, 2021 8:02 am

Ok for the apu fault message , I linked it to the Apu f7 yellow light condition .
We can put the condition on apu failure instead . I don’t remember if they had that nuisance fault in real ( I know they had a couple of them that popped here and there and where disregarded depending of the context ).

I will change that in the cws.nas next week , I am out of a the computer for a week


For the manual meco , we have it pretty right I think.
Every time they mentioned a manual throttle procedure ,manuel meco with push buttons is also therein the checklist .


For the flames, I remember I had that a year ago while playing with minimum thrust values .
I observed that below 67 pour-cent , the flames were not visible anymore .
I tried a rtls yesterday with manual minimum thrust and I had 67 with some ssme visuals
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Mon Feb 22, 2021 3:33 pm

Ok for the apu fault message , I linked it to the Apu f7 yellow light condition .
We can put the condition on apu failure instead . I don’t remember if they had that nuisance fault in real ( I know they had a couple of them that popped here and there and where disregarded depending of the context ).


I guess the point is that the light coming on in a transient fashion was kinda okay, but since we now get the full master alarm blaring this is really distracting. So I introduced a property to veto the underspeed check for 5 seconds after a run command has been given - problem solved.

Also, @eatdirt was right and the throttle animation was backwards, so I reversed it, looked okay to my keyboard handling now.
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Re: Space Shuttle - Bugfixes

Postby GinGin » Mon Feb 22, 2021 8:01 pm

Ok perfect for the APU fault.
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Re: Space Shuttle - Bugfixes

Postby eatdirt » Mon Feb 22, 2021 9:38 pm

the throttle animation was backwards, so I reversed it, looked okay to my keyboard handling now.


Thanks! Tested, all works, animation and throttling. I've also tested the BFS light enroute to Hubble, fix works, it does not blink any more with GPC5 off during the transitions OPS 201 <-> 202.
I may mention that, however, at each transition from 202 -> 201, the DAP gets reset to its default mode (A, INRTL). This is not new, but thinking about it, it may not be expected?
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Tue Feb 23, 2021 7:20 am

This is not new, but thinking about it, it may not be expected?


That happens because

OPS 201 PRO

isn't 'just' a major-mode transition but interpreted as the OPS transition to 2, aka when you're in OPS 1 after insertion and give the command, it ends the transition DAP and enables full orbital DAP. which is why it resets to the standard condition (all X01 transitions have that property, but you normally never transit to 101 and never come back to 301 or 601 from a higher mode).

Of course on-orbit you may not be using it as OPS transition but to go back from a burn in OPS 202. But in a sense, that too requires some specific DAP setting (OMS TVC for instance) which you wouldn't want to keep transiting to attitude management in 201.

So why is that a problem?

(I'm not quite sure how reality was handled, but I believe we're not wrong...)
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Re: Space Shuttle - Bugfixes

Postby eatdirt » Tue Feb 23, 2021 5:18 pm

So why is that a problem?


It's not a problem at all :) But the thinking came from the following situation which I have triggered a few times: Let us say that for the purpose of equalizing thermal stresses over the spacecraft , you're in a slow rotation (which also helps for freon temperature regulation), then you move back to OPS 201 for any reason, you cannot escape the DAP to automatically stops this rotation and burn some fuel?
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Wed Feb 24, 2021 7:07 am

then you move back to OPS 201 for any reason, you cannot escape the DAP to automatically stops this rotation and burn some fuel?


Yes, but the only reason you'd want to move to 201 is to do an OMS burn, and the only way you can do an OMS burn is if you stop the rotation and move to OMS attitude, there is no scenario in which you need the capability to do an OMS burn but keep rotating :D
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Wed Feb 24, 2021 2:34 pm

Seems our in-sim checklists do not require the TVC valves opened before transiting to OPS 3, failure to do so leads to the SSME REPOSFAIL fault message, so I've added the item to the checklist.
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