YASKAWA S Series User Manual page 100

5.9 Adjustments
5.9.1 Servo System Adjustments
rameters) are used to adjust the servo system.
A simple block diagram of the servo system is shown below.
Spee
Speed pattern
MECHATROLINK
command
■ Basic Rules for Gain Adjustment
The servo system is equipped with the following feedback systems.
The inner loops require better response. Failure to follow this principle will result in poor re-
The responses of the position loop and speed loop must be kept in balance. Increasing the posi-
Once the load inertia constant (Cn-0003) has been specified, the following user constants (pa-
• Cn-0004: S p e e d Loop Gain
• Cn-0005: S p e e d Loop Integration Time Constant
• Cn-0017: To r q u e Reference Filter Time Constant
• Cn-001A: Position Loop Gain
Error
counter
Time
• • • • • • • • • • o
Position loop
Figure 5.9 S e r v o System Block Diagram
• Position loop
• Speed loop
• Current loop
sponse and vibration.
The current loop already provides adequate response and cannot be adjusted by the user. The user
can adjust the position loop and speed loop gains. The speed loop integration time constant and
torque reference filter time constant can also be adjusted by the user.
tion loop gain alone to improve response will cause the speed reference in the SERVOPACK to
vibrate, producing slow or inconsistent positioning times. If the position loop gain is increased,
the speed loop gain must be similarly increased.
Speed K v
Kp
control
section Ti
. • • • •
Speed loop
Kp: Position loop gain
Kv: Speed loop gain
Ti: Integration time constant
5 -19
5.9 Adjustments
Motor
S M
Current
Powe
1111111••
control
con-
section verter
Current loop
(1.1)
Encoder