Fix Version/s: None
Sprint:TSSW Sprint - Jul 6 - Jul 20, TSSW Sprint - Jul 20 - Aug 3
Team:Telescope and Site
Fix the following error in the rotator Simulink model. There is the problem of physical model in plant that the rotator's position will differ from the related position command gradually until the trigger of followingError (the difference >= threshold) and this stops the motion of rotator. According to the observation, this happens if the rotator moves in the negative direction.
In the following figure, there are two targets: (1) position=1.2 deg and velocity=0.01 deg/sec and (2) position=1.5 deg and velocity=-0.01 deg/sec. The total simulation time is 20.1 sec. There is no big difference between the position command and position. The error of noNewTrackCmdError after the slew of the second target is triggered as expected.
However, if the second target has position=-1.5 deg and velocity=-0.01 deg/sec, the following error is triggered while the rotator turns the direction to slew to the second target:
Tiago Ribeiro Please see the page 3, 18, and 19 for the discussion of gravity in:
2016-06-01 LSST CDR - Control System Design and Analysis_1.pptx
These are the only information I could found.
Uhm, ok... but none of them specify where the inclination is coming from. I think it is ok for now but we should probably investigate this to make sure the model and the real thing are getting and using this information properly.
I totally agree with this comment because the information of MOOG documents is very limited. I should document it when I do the debug of the gravity model (I do not know when it will be). Thanks!
Great work done by TeWei and Mike on this ticket. I think it's good to go, we will have some additional work to follow up but it is looking good.
Can you clarify one thing for me please? How does the model compute the gravity compensation? I imagine it will need to know the inclination of the system to be able to compute it. If this is the case, where this information is coming from on the model and on the real system?