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Motor[x].ActVel dropping to zero occasionally
#1
Aloha,

While moving our telescope I was watching the Motor[x].ActVel register in the IDE scope and saw that it was tracking the telescope velocity then it starts to briefly drop to 0 and then goes back up to the constant velocity that the telescope is at.

What could be the causes of this? Is this register calculated from the Pos2 encoder entry? Could it be an encoder noise issue or corruption in bits from the absolute encoder?

On the large scale it looks like the currents are fine so I'm not sure if the servo loop is being affect by this.

thanks,
windell
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#2
Yes - this is from the inner loop position sensor. It is basically the difference of the inner-loop actual position values for this and the previous servo cycle. Compare it to Motor[x].DesVel to see if this is the actual command value. It could be encoder noise - plot this also to see if there is a relationship.
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#3
Looks like we're onto something. I will do that plot to see what is up.

We have a max delta filter running in the encoder table for each of our encoders. Since the ActVel is for the motor position, I'm assuming that seeing these drops means that they are making it past this filter?

thanks,
windell

(04-08-2016, 10:28 AM)steve.milici Wrote: Yes - this is from the inner loop position sensor. It is basically the difference of the inner-loop actual position values for this and the previous servo cycle. Compare it to Motor[x].DesVel to see if this is the actual command value. It could be encoder noise - plot this also to see if there is a relationship.
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