RMS Coordinates - OMS Propellant Readout

[Becker]

Having trouble grappling the OBSS am using the coordinates from STS-115 PDRS 3-15.


It looks like the End Effector is in the right position but it will not grapple. Also the 'T' at the opposite end of the OBSS which aligns with the T on the cradle is rotated slightly clockwise.


Only reason I mentioned it is it doesn't match with the image and was wondering if this has anything to do with my issue. Lastly on the RMS I have trouble hitting the precise digital readout with the numbers over/undershooting in the decimal range due to the speed of the RMS. In this instance I nailed all the coordinates exactly as per the PDRS but still failed to achieve capture. Is there a method I am missing for fine tuning?

Regarding OMS Prop when I use SYS SUM double press in OPS 201/202 to check propellant levels the page loads but the readouts are blank.

 

[DaveS]

Remember, SSU is alpha level software, if even that. Many systems are not implemented and that includes the OMS and RCS. The DPS is a very basic and very bug-ridden version of the real thing. It doesn't do System Management (SM), only ascent and on-orbit GN&C.

If you want to know the OMS/RCS propellant tank levels, use the RCS/OMS PRPLT QTY LEDs on panel O3.

 

[GLS]

I created a ticket for the OBSS marking sometime ago... can't do more than that.
I'll try to see if I can figure out the EE position issue.

On the OMS (RCS) stuff... IMO, currently it's somewhat of a mess... the only outputs are the quantities on panel O3 and the chamber pressure on the OMS/MPS display. The SYS SUMM displays are basically static ATM, with only the BFS GNC SYS SUMM 1 displaying some info (and some a second display that I can't remember now).

 

[DaveS]

I created a ticket for the OBSS marking sometime ago... can't do more than that.
I'll try to see if I can figure out the EE position issue.

On the OMS (RCS) stuff... IMO, currently it's somewhat of a mess... the only outputs are the quantities on panel O3 and the chamber pressure on the OMS/MPS display. The SYS SUMM displays are basically static ATM, with only the BFS GNC SYS SUMM 1 displaying some info (and some a second display that I can't remember now).

Yes. Everything is a mess right now. So you should be surprised that things doesn't work according to the check-lists.

 

[GLS]

Having trouble grappling the OBSS am using the coordinates from STS-115 PDRS 3-15.

So a did a quick check and the positions are wrong somehow, but using the joint angles it grappled with no problems. I created a ticket and will (try to) look at this after I'm done with the A/E PFD. Meanwhile, use only the joint angles... :shrug:

 

[Becker]

Thanks for the help. OMS prop levels on O3 check. Despite reading up on the checklists/manuals (which i'm really enjoying) it isn't always clear what does and doesn't work in SSU apart from really obvious items like switch throws or blank CRT pages. I appreciate this is all still very much a work in progress.

The RMS is still proving troublesome despite using the coordinates on the checklist and other positions. First issue was with the open talk back showing barber pole with derigid and extend gray. I fixed this with a quick save and restart giving me three gray lower talk backs.

When I command rigid the extend talkback goes bp - open stays gray - derigid goes bp. This is followed by rigid gray with close and capture remaining bp. Tbh this is not really an issue with regard to my enjoyment of SSU atm just curious as to why I can't nail it.

 

[Becker]

So a did a quick check and the positions are wrong somehow, but using the joint angles it grappled with no problems. I created a ticket and will (try to) look at this after I'm done with the A/E PFD. Meanwhile, use only the joint angles... :shrug:

I appreciate you're busy with other stuff but if you do get a chance could you give me the joint angles with which you achieve the grapple. This is as far as I am at the moment.
SY-90 SP 76.5 EP -134.6 WP -40.9 WY 0 WR 102

 

[DaveS]

Are you sure that you have the END EFFECTOR MODE switch on A8U in the AUTO position? I have no problems grappling the OBSS.

 

[GLS]

I appreciate you're busy with other stuff but if you do get a chance could you give me the joint angles with which you achieve the grapple. This is as far as I am at the moment.
SY-90 SP 76.5 EP -134.6 WP -40.9 WY 0 WR 102

I used the ones on the first post (which seem to be the ones you posted now)... I don't remember how close it was to "perfection", but I think it was closer than that.
Anyway, I'd say that's probably what is intended: some overlap between the pin and the EE edge, so capture can take place.
Does it grapple like that? If it doesn't try and close the gap a bit, because in real life those numbers are not supposed to be milimetrically precise due to thermal expansion/contraction of the arm and also sensor imprecision (but they are also not supposed to be way off like the position values bug you reported :lol.

 

[Becker]

Are you sure that you have the END EFFECTOR MODE switch on A8U in the AUTO position? I have no problems grappling the OBSS.

It must be something i'm doing wrong in the procedures. Nothing happens when I have the EE mode switch in auto.

Is the capture switch the rigid/derigid switch?
Can you give me a rundown on the grapple procedure from that panel state please? The end effector is currently in the position of my previous post.

 

[DaveS]

It must be something i'm doing wrong in the procedures. Nothing happens when I have the EE mode switch in auto.

Is the capture switch the rigid/derigid switch?
Can you give me a rundown on the grapple procedure from that panel state please? The end effector is currently in the position of my previous post.

To grapple/ungrapple you need the END EFFECTOR MODE switch in AUTO and then press Ctrl-Enter. This will start the grappling/ungrappling sequence.

---------- Post added at 05:43 PM ---------- Previous post was at 03:56 PM ----------

Correction: Ctrl-Enter starts the grappling sequence while Ctrl-Backspace starts the ungrappling sequence.

 

[Becker]

Thanks now all sorted - I was reading so many different checklists I forgot to RTFM ...

It is all for a good cause as am working on a little project both to educate myself and hopefully other SSU learners. Hooked

 

[Becker]

In the scenario file which values represent which propellant/tank? I figured the first four are OMS APUx3 but what are the others?

PRPLEVEL 1:1.000000 2:0.920832 3:1.000000 4:1.000000 5:1.000000 6:1.000000 7:1.000000 8:0.999000 11:0.020000

 

[GLS]

In the scenario file which values represent which propellant/tank? I figured the first four are OMS APUx3 but what are the others?

PRPLEVEL 1:1.000000 2:0.920832 3:1.000000 4:1.000000 5:1.000000 6:1.000000 7:1.000000 8:0.999000 11:0.020000

In all honesty: I don't know. :facepalm:
I do know that the ET prop level is controlled by the entry in the ET vessel. After a quick look at the code I think 1 is MPS manifold, 2 is OMS, 3 SRBs???, 4-6 is APU, 7 OMS He (not used), 8 FRCS, 9-10 ARCS (might not be used) and 11 is a dummy prop resource for the THC and RHC (should not be 0). But then these IDs change as the vehicle config changes so....

It is to avoid situations like this that SSU needs to have an automated scenario/mission creation tool, because there are just so many things to control manually. The problem is that SSU has on average about 0.7 coders working at anytime.