position / speed mode - Harmonic Drive LLC

Chapter 6Setting up parameters
Feed forward gain
[Tune mode]
(position mode)
Function
In the position mode the HA-655 driver controls the error
count, the difference between [command pulse] and
[feedback pulse], to be [0]. At the beginning of inputting a
command pulse train, the actuator starts slowly because
of a of small error count.
The [feed forward] function may accelerate the actuator as
much as possible, adding the speed commands to the
speed control loop. The speed commands are converted
from a command pulse frequency (feed forward rate =
100%). The feed forward function provides acceleration
control, minimizing the position error. The effects of the
feed forward are disabled when the feed forward rate
equals 0%.
Command
Feed forward
Error pulse
HA-655
Position
control
Feedback pulse
FHA
1st digit
U P D O W N A D J S E T
Feed forward
Feed forward rate
unit:
6th digit
The relation between the gain and actuator motion is as follows:
Excessive gain causes mechanical shock and hunting.
Details of display
1st digit: [3:Feed forward gain]
2nd to 3rd digit: No indication
4th to 6th digit: indicates current [Feed forward gain]. A value from [0] to [100] can be set.
Operations
(1) To change a value, press the [ADJ] key at least 0.1 second.
1st digit [3] flashes. You can change the value.
(2) When the actuator does hunting or mechanical shock occurs, press the [DOWN] key and set a
lower value. When the position following to command is poor, press the [UP] key to set a higher
value.
(3) To define the new value, press the [SET] key at least 0.1 second.
Flashing of 1st digit [3] stops and the new value is defined.
(4) To cancel a change in operation, press the [ADJ] key at least 0.1 second.
Flashing of 1st digit [3] stops and the previous value becomes effective.
Related functions
[Speed loop gain]:
[tune mode][0:Speed loop gain]
[Speed loop integral compensation]: [tune mode][1:Speed loop integral compensation]
[Position loop gain]:
[tune mode][2:Position loop gain]
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