Eric Johnson wrote: > Hi all, > > I have a servo motor axis configured angular with a relatively low > resolution encoder / gear ratio. One revolution of the shaft is 19600 > counts, or 54.4444 counts per degree. I was having a very difficult time > tuning it at 54 counts per degree, so I set the counts per engineering > unit to one revolution, or 19600. I had no problem tuning it in at this > resolution. Positioning error and overshoot were negligible. > Yes, I have observed the same behavior, but still do not understand the cause. I am guessing the problem is due to the double-quantized nature of the encoder, both in time (sampling) and in position. As the INPUT_SCALE number gets smaller, the relative size of the quantization becomes bigger. The time-stamped velocity estimation should help somewhat in this area, but the position quantizing can't be fixed.
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