Chapter 4 Configuring the Joint Parameters
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4.7.2.3 Operating procedure for manual gain tuning
(1) Initializing positioning loop gain
First set the positioning loop gain to almost the same value of that calculated from
natural frequency of the connected mechanism.
If the natural frequency is 20 Hz, set the positioning loop gain to 41 which equals to
20 256/125 as calculated by Formula 4.7-1. If the natural frequency is unknown,
use the default value 64.
(2) Tuning torque
If almost constant, unbalanced load (e.g., force of gravity) applies to the motor,
then set the torque offset calculated from the load.
(3) Obtaining the limit of speed linear loop gain
While increasing the speed linear loop gain gradually, find the upper limit of the
loop gain at which the connected mechanism will start producing abnormal noises
or oscillations.
(4) Checking the effect of the torque control filter setting
First set the torque control filter parameter to "0" and find the upper limit of speed
linear loop gain again. If the speed linear loop gain obtained here is lower than the
previous one obtained in step (3), reset it to 8 (default).
(5) Determining the appropriate speed linear loop gain
Apply 80% of the limit obtained in steps (3) and (4) to the speed linear loop on the
connected mechanism.
(6) Tuning the speed Integral loop gain
Gradually increase the speed integral loop gain so that the positioning time and
peaks of overshoot and undershoot will be minimized to optimize the connected
mechanism.
(7) Tuning the positioning loop gain
If the connected mechanism is still oscillatory after carrying out the procedure in
step (6), then decrease the positioning loop gain.
If you decrease the positioning time further after tuning in steps (3) through (6),
then gradually increase the positioning loop gain to the extent that no noise or
oscillation will be produced.
(8) Tuning the positioning loop feed forward gain
If you further decrease the positioning time of the connected mechanism, gradually
increase the positioning loop feed forward gain to extend that no oscillation will be
produced.
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