Procedure 1. Set both ARF0 and ARF1 to 400 Hz and set KVP low enough
to prevent oscillation.
2. Increase KVP slowly until oscillation at the resonant
frequency just begins. Then, reduce KVP slightly until the
oscillation just stops. Compute the velocity loop bandwidth
using the formula given at the beginning of this section. If
the velocity loop bandwidth is less than .25 times the value
of ARF0 and ARF1, then proceed to Step 3. Otherwise, go to
Step 4.
3. Decrease both ARF0 and ARF1 by 20% and go back to Step
2.
4. The velocity loop bandwidth should now be approximately
one quarter the value of ARF0 and ARF1. For margin,
reduce KVP, ARF0, and ARF1 by 20%.
Backlash Some backlash may be unavoidable, especially when gear
reduction is used. If backlash is present, the inertia match must
be good (load inertia should be roughly equal to motor inertia) for
good servo performance. Gearing reduces the inertia reflected to
the motor by the square of the gear reduction from motor to load.
Therefore, select a gear ratio to give the required match.
4-6 MA950
To Next Page