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7. ADJUSTMENT
7. ADJUSTMENT
7.1 What Is Gain Adjustment?
7.1.1
Difference between servo amplifier and other drives
Besides the servo amplifier, there are other motor drives such as an inverter and stepping driver. Among
these drives, the servo amplifier requires gain adjustment.
The inverter and stepping driver are in an open loop (actual motor speed and position are not detected on
the driver side).
M
L
Load
Motor
Inverter
On the other hand, the servo amplifier always detects the positions and speeds of the motor and machine
using the servo motor encoder, and exercises control to match the position and speed commands with the
actual motor (machine) position and speed. In the servo system, adjustment is needed because:
M
L
Servo amplifier
Load
Encoder
Servo motor
(1) Response changes according to the inertia moment of the machine;
(2) Vibration occurs due to the resonance point, etc. peculiar to the machine; and
(3) Operation delay and accuracy specification differ between machines and response should satisfy this
specification.
