Russell suggests something like this in the trigger of slew:

in_position = (actual_position - commanded_position_at_current_time) < pos_limit and (actual_velocity - commanded_velocity) < some_value

Russell suggested:
 
Note that you have to extrapolate or interpolate the commanded position to the current time (the time at which you sample the current position) for this to work properly
 

There is the extrapolation of position in the subsystem of posErrorCalc_OldCmd already. 
Add the subsystem of compareDiffVelWithThold in the subsystem of slewAndTrackingParameters.

Track the single target without the problem:

Track two targets without the problem:

Because MOOG only considers the simplest case in the tracking, this new velocity test should have no affection to the existed algorithm. The interesting part is to test some edge case to see how to break the original algorithm.

I intentionally to make a fake tracking condition that two targets have the same position but different velocities (0.01 deg/sec vs -0.01 deg/sec):

It looks like the rotator can track without breaking it (I expected to break it actually):

I think this is because the tracking algorithm has the wrong (unphysical) behavior originally. We can see the discontinuity of velocity at time=6.15 sec:

 This will wait the Tekniker to fix it.

Please help to review the PRs:
1. https://github.com/lsst-ts/ts_mt_hexRot_simulink/pull/16
2. https://github.com/lsst-ts/ts_rotator_controller/pull/20

Thanks!

There isn't anything I can see that I can review, but I'll approve it based on the graphs in this ticket.