PMA Actuator problem?, Diagnostics began sol 2257 Options

[alan]

CODE

02259  12:27:42  p2864.04. 2    0   0   1   0   0   1   pancam_PMA_actuator_diagnostic_L2

What's a PMA actuator?

edit: found it, PMA is the Pancam Mast Assembly, they must be determining why the pancam didn't turn when the drive direction mosaic was taken.

[Tesheiner]

Saw those sequences too.
The PMA actuators are those *very* important motors which command navcam and pancam yaw and tilt.

Glad to know the pancam tracking web is being updated again and hope there's nothing wrong with those actuators.

[fredk]

Yikes, I didn't realize the sol 2257 pancams were supposed to be drive direction:
http://marsrovers.jpl.nasa.gov/gallery/all...nity_p2256.html
And presumably the subframes were supposed to crop on the Sun, but it wasn't in the field of view.

Those pics should've come down some time Monday, which would explain why there was no mention of this in the PS report.

Obviously the azimuth is opposite to what it should've been for drive direction, but the top of the R1 frames is just a few degrees below the horizon. So if the rover tilt is right, it's possible that the pancam altitude was correct, and just the azimuth was wrong. I'm sure we can all speculate on what that could mean, but we really need some information before our imaginations run too wild.

[centsworth_II]

...presumably the subframes were supposed to crop on the Sun, but it wasn't in the field of view....

Maybe they better stop taking those pictures of the sun. It would not be good to have a tilt actuator fail with the Pancam pointed up. At least if it is horizontal to the surface something could be done with rover movements to get desired shots.

[marsophile]

Maybe they better stop taking those pictures of the sun.

I believe the shots of the sun are needed to reset the precise attitude of the rover. They would have to come up with some substitute method of determining the fine attitude to correct the errors that eventually accumulate from dead reckoning.

[jamescanvin]

Yikes indeed! Loss of a PMA actuator would be a major blow.

Just been looking at the PDT. Interesting that the mast head didn't move in either el or az - I'm assuming that there have separate actuators for each?

The good news is the PMA_diagnostic thumbnails do show some change in both el and az.

Code from the PDT site below - last two columns are az and el respectivly.

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*Sun find*
/oss/merb/ops/ops/surface/tactical/sol/2257/opgs/edr/pcam/1P328550110ETHAHQ8F0006L8M1.IMG::117::684::0.266769::13.4113

*Drive Direction*
/oss/merb/ops/ops/surface/tactical/sol/2257/opgs/edr/pcam/1P328550320ETHAI00P2442R1M1.IMG::118::0::0.266769::13.4113
/oss/merb/ops/ops/surface/tactical/sol/2257/opgs/edr/pcam/1P328550356ETHAI00P2442R1M1.IMG::118::0::0.266769::13.4113
/oss/merb/ops/ops/surface/tactical/sol/2257/opgs/edr/pcam/1P328550393ETHAI00P2442R1M1.IMG::118::0::0.266769::13.4113
/oss/merb/ops/ops/surface/tactical/sol/2257/opgs/edr/pcam/1P328550428ETHAI00P2442R1M1.IMG::118::0::0.266769::13.4113

*PMA Diagnostics*
/oss/merb/ops/ops/surface/tactical/sol/2259/opgs/edr/pcam/1P328726770ETHAI00P2864L2M1.IMG::118::0::0.266769::13.4113
/oss/merb/ops/ops/surface/tactical/sol/2259/opgs/edr/pcam/1P328726824ETHAI00P2864L2M1.IMG::118::0::0.266769::13.416
/oss/merb/ops/ops/surface/tactical/sol/2259/opgs/edr/pcam/1P328726869ETHAI00P2864L2M1.IMG::118::0::0.266769::13.4097
/oss/merb/ops/ops/surface/tactical/sol/2259/opgs/edr/pcam/1P328726918ETHAI00P2864L2M1.IMG::118::0::0.0800684::13.4097
/oss/merb/ops/ops/surface/tactical/sol/2259/opgs/edr/pcam/1P328726956ETHAI00P2864L2M1.IMG::118::0::0.129489::13.4097

[James Sorenson]

I as well hope the issue with PMA actuators is resolved.

Also I might point out, whats with these lines in the PDT? The "cleatcam" images usually point to something wrong, or so I thought.

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02259 12:32:23  118     4        1 p1394.01 1                          *               rear_right_haz_cleatcam_4_bpp_pri_23
02259 12:31:37  118     2        1 p1394.01 1                          *               rear_right_haz_cleatcam_4_bpp_pri_23
02259 12:30:27  118     0        1 p1394.01 1                          *               rear_right_haz_cleatcam_4_bpp_pri_23

[jamescanvin]

iirc, many of the actuators share control electronics (some of the wheels with some in the arm at least). I guess that the PMA shares with the right rear wheel and so these images are another diagnostic of the same problem.

[James Sorenson]

Thanks James.

Was there supposed to be commanded motion of the RR wheel at the time those Haz images were taken? If so judging from the thumbnails on the tracking site, I see none.

[fredk]

The good news is the PMA_diagnostic thumbnails do show some change in both el and az.

Thanks for posting that data, James. Both az and el are tiny movements, but especially elevation. But the important question is how much movement was commanded. If there seems to be a problem, I could imagine that they commanded only small diagnostic movements to start. I really hope that was the case. We'll have to wait for some info to trickle out.

[Tesheiner]

I see not only tiny movements but also that those were commanded on a single axis at each sequence. I.e. tilt first, then yaw. Consistent with a diagnostic to see the behaviour (voltage & current ?) of each individual motor.
There's more diagnostic planned for thisol.

The next status report may give us a hint about the issue.

[fredk]

Sol 2259 pics are down:
http://marsrovers.jpl.nasa.gov/gallery/all...nity_p2258.html
http://marsrovers.jpl.nasa.gov/gallery/all...nity_r2258.html
You can see movement in the pancam sequence like Tesheiner described based on the data:

You have to look closely near the bottom edge to see the elevation movements, which come first in the sequence of 5 frames.

I can't see any movement in the hazcams, though of course we don't know if any was sequenced.

[fredk]

This is truly bizarre: this image somehow received the wrong timestamp:
http://marsrovers.jpl.nasa.gov/gallery/all...APP0666R0M1.JPG
The timestamp decodes as the beginning of sol 2260, which can't be right since we're long past Concepcion now, and it'd be dark at midnight anyway...

[jamescanvin]

Some more very small motions of the PMA in tosols tracking data. And increments in the drive number indicating some commanded motion of the RR wheel I guess.

CODE

/oss/merb/ops/ops/surface/tactical/sol/2261/opgs/edr/pcam/1P328904931ETHAI04P2868L2M1.IMG::118::4::-24.0682::9.73096
/oss/merb/ops/ops/surface/tactical/sol/2261/opgs/edr/pcam/1P328904967ETHAI04P2868L2M1.IMG::118::4::-24.0679::9.73251
/oss/merb/ops/ops/surface/tactical/sol/2261/opgs/edr/pcam/1P328904994ETHAI04P2868L2M1.IMG::118::4::-24.0687::9.72787
/oss/merb/ops/ops/surface/tactical/sol/2261/opgs/edr/pcam/1P328905039ETHAI04P2868L2M1.IMG::118::4::-24.243::9.75514
/oss/merb/ops/ops/surface/tactical/sol/2261/opgs/edr/pcam/1P328905073ETHAI04P2868L2M1.IMG::118::4::-24.1207::9.736
/oss/merb/ops/ops/surface/tactical/sol/2261/opgs/edr/pcam/1P328905249ETHAI06P2867L2M1.IMG::118::6::-24.1175::9.73351
/oss/merb/ops/ops/surface/tactical/sol/2261/opgs/edr/pcam/1P328905270ETHAI06P2867L2M1.IMG::118::6::-24.1175::9.73351
/oss/merb/ops/ops/surface/tactical/sol/2261/opgs/edr/pcam/1P328912524ETHAI06P2868L2M1.IMG::118::6::-24.1175::9.73351
/oss/merb/ops/ops/surface/tactical/sol/2261/opgs/edr/pcam/1P328912561ETHAI06P2868L2M1.IMG::118::6::-24.1172::9.73505
/oss/merb/ops/ops/surface/tactical/sol/2261/opgs/edr/pcam/1P328912588ETHAI06P2868L2M1.IMG::118::6::-24.118::9.73042
/oss/merb/ops/ops/surface/tactical/sol/2261/opgs/edr/pcam/1P328912633ETHAI06P2868L2M1.IMG::118::6::-24.4231::9.77827
/oss/merb/ops/ops/surface/tactical/sol/2261/opgs/edr/pcam/1P328912668ETHAI06P2868L2M1.IMG::118::6::-24.264::9.75331
/oss/merb/ops/ops/surface/tactical/sol/2261/opgs/edr/pcam/1P328912865ETHAI08P2867L2M1.IMG::118::8::-24.264::9.75467
/oss/merb/ops/ops/surface/tactical/sol/2261/opgs/edr/pcam/1P328912886ETHAI08P2867L2M1.IMG::118::8::-24.264::9.75467

[fredk]

Some more very small motions of the PMA in tosols tracking data.

Thanks again, James. Notice how the movements are very small, but the az/el positions are very differrent from sol 2259. I couldn't see any thumbnails at the tracking site to confirm the change in pointing. Even if it did change, it might be due to a drive, if there was a drive. Lots of ifs.