# Review the Control Algorithm of Rotator in Phase 1

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#### Details

• Type: Story
• Status: Done
• Resolution: Done
• Fix Version/s: None
• Component/s:
• Labels:
• Story Points:
3
• Sprint:
TSSW Sprint - May 11 - May 25, TSSW Sprint - May 25 - Jun 08
• Team:
Telescope and Site
• Urgent?:
No

#### Description

This task will review the control algorithm of rotator in Simulink model and try to translate to the math equations. This is try to understand the behavior of stop command in the tracking. In the previous test on summit, we learned that the path generator has the weird behavior if stop command was issued in the tracking. We suspect the stop command results in the wrong behavior of path generator.

#### Activity

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Te-Wei Tsai added a comment - - edited

Reviewed the csa-questions-icd_comments_pjl.docx and noticed the followings:
1. We do not think this is a problem since the Rotator control will be doing a fit (spline interpolation, likely) to determine a smooth trajectory through the provided setpoints. --> This might be a problem when we change the direction of tracking target.
2. Note that while consecutive setpoints may instantaneously change direction, the control will smooth the rotator motion according to the dynamics of the system. The implication is that the rotator will not satisfy the inPosition criterion until it has completed the slew and changed direction.

A related document is CDR - Software V2.pptx.

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Te-Wei Tsai added a comment - - edited Reviewed the csa-questions-icd_comments_pjl.docx and noticed the followings: 1. We do not think this is a problem since the Rotator control will be doing a fit (spline interpolation, likely) to determine a smooth trajectory through the provided setpoints. --> This might be a problem when we change the direction of tracking target. 2. Note that while consecutive setpoints may instantaneously change direction, the control will smooth the rotator motion according to the dynamics of the system. The implication is that the rotator will not satisfy the inPosition criterion until it has completed the slew and changed direction. A related document is CDR - Software V2.pptx .
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Te-Wei Tsai added a comment -

Reviewed the H&R Software Acceptance Notes - INTERNAL DISTRIBUTION ONLY.docx and noticed the followings:
Hard to describe, but in one occasion we had to restart everything because it got into an uncontrollable state. In another occasion we had to restart everything because Harini closed a window using the X rather than exit button… I am concerned the operability of the software is not as good as it should be.

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Te-Wei Tsai added a comment - Reviewed the  H&R Software Acceptance Notes - INTERNAL DISTRIBUTION ONLY.docx and noticed the followings: Hard to describe, but in one occasion we had to restart everything because it got into an uncontrollable state . In another occasion we had to restart everything because Harini closed a window using the X rather than exit button … I am concerned the operability of the software is not as good as it should be.
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Te-Wei Tsai added a comment -

Reviewed the  Rotator Tracking Requirements Discussion.pptx and noticed the followings:
1. There are the position and velocity trajectories in the tracking.

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Te-Wei Tsai added a comment - Reviewed the  Rotator Tracking Requirements Discussion.pptx and noticed the followings: 1. There are the position and velocity trajectories in the tracking.
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Te-Wei Tsai added a comment - - edited

The introduction of rotator control model is Hexapods & Rotator Regular Telecon 2016 Mar 14.pptx.

The further discussion is  2016-04-01-LSST Command Module.pptx.

The analysis of algorithm is  2016-06-01 LSST CDR - Control System Design and Analysis_1.pptx. The discussion of Stop command began here.

The discussion of Stop command is 2016-06-27 Response to FDR Action Items_revA.pptx.

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Te-Wei Tsai added a comment - - edited The introduction of rotator control model is Hexapods & Rotator Regular Telecon 2016 Mar 14.pptx . The further discussion is  2016-04-01-LSST Command Module.pptx . The analysis of algorithm is  2016-06-01 LSST CDR - Control System Design and Analysis_1.pptx . The discussion of Stop command began here. The discussion of Stop command is 2016-06-27 Response to FDR Action Items_revA.pptx .
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Te-Wei Tsai added a comment - - edited

Verified the case 1 in slew here: controlAlgorithmCase1.nb

Verified the case 2 in slew here: controlAlgorithmCase2.nb

Verified the case 3 in slew here: controlAlgorithmCase3.nb

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Te-Wei Tsai added a comment - - edited Verified the case 1 in slew here:  controlAlgorithmCase1.nb Verified the case 2 in slew here:  controlAlgorithmCase2.nb Verified the case 3 in slew here:  controlAlgorithmCase3.nb
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Te-Wei Tsai added a comment - - edited
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Te-Wei Tsai added a comment - - edited Created the  Trajectory Generator in Rotator . Added the  Position-Related Acceleration Trajectory Component .
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Te-Wei Tsai added a comment -
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Russell Owen added a comment -

This looks good. I made a few minor edits to both confluence pages. Please feel free to undo any changes you dislike. (I didn't turn on notifications because Confluence is so unreliable that I save often, and I didn't want to flood anyone with change notifications).

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Russell Owen added a comment - This looks good. I made a few minor edits to both confluence pages. Please feel free to undo any changes you dislike. (I didn't turn on notifications because Confluence is so unreliable that I save often, and I didn't want to flood anyone with change notifications).

#### People

Assignee:
Te-Wei Tsai
Reporter:
Te-Wei Tsai
Reviewers:
Russell Owen
Watchers:
Russell Owen, Te-Wei Tsai
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Watchers:
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#### Dates

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#### Jenkins

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