Details
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Type:
Story
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Status: Done
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Resolution: Done
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Fix Version/s: None
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Component/s: ts_main_telescope
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Labels:
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Story Points:0
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Epic Link:
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Sprint:TSSW Sprint - Nov 07 - Nov 21
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Team:Telescope and Site
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Urgent?:No
Description
Check the code of M2 mirror safety in control system:
1. How does the system deal with the condition that the actuator force is more than the threshold?
2. Does the system check the tangent links in X, Y and Mz and check them relative to the expected values as a function of elevation angle?
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After digging into Harris's M2 cell code, I think the developers did check the glass safety in the code and fault the system (or stop the motion) when something is wrong. The threshold values are hard-coded, but this is another question actually.
We may need to use the surrogate to test what might be the good threshold values. Since they are hard-coded, the change of new values means the recompilation + deployment. This will need to use the new cRIO-9049. Hope the hard-coded values are good before EIE returns me the cRIO.
Thanks for looking for this Te-Wei. I've requested the cRIO from EIE and it sounds like they started the shipping process. Hopefully we will see it soon.
In the ts_mtm2_cell, the TelemetryFaultManager.check_for_faults.vi will check the actuator forces with the limits and fault/stop the motion if the value is more than the threshold:
I also found the TangentLoadCellFaultDetection.vi in the ts_mtm2_cell to check the fx, fy, and mz and compare with the threshold:
Interesting thing is that I saw this vi before in the ts_mtm2, and I did not understand why Harris developers had two copies of this vi under cRIO and server sides.
Fortunately, in the previous time, Patricio Cortes helped to translate the math here:
https://confluence.lsstcorp.org/display/LTS/Tangent+Load+Cell+Fault+Detection