11-29
11 Adjustment Functions
G5-series AC Servomotors and Servo Drives User’s Manual (with Built-in EtherCAT Communications)
11-9 Friction Torque
Compensation Function
11
11-9-3 Operation Example
The friction torque compensation is applied in the input direction of the position command as shown in
the drawing below.
The Torque Command Value Offset (3607 hex) reduces the variations of positioning operations due to
the movement directions when a certain amount of unbalanced load torque is always applied to the
motor at the vertical axis by setting the torque command.
By setting the friction torque for each rotation direction in the Forward Direction Torque Offset
(3608 hex) and Reverse Direction Torque Offset (3609 hex), you can reduce the deterioration of and
inconsistencies in the positioning stabilization time due to dynamic friction for loads that require a large
amount of dynamic friction torque due to a radial load, such as the belt-driven shaft.
Precautions for Correct UsePrecautions for Correct Use
You can use the unbalanced load compensation and the dynamic friction compensation together
or separately. Take note that the following use limit is applied upon control mode switching or
servo ON.
• During Torque Control
The unbalanced load compensation and the dynamic friction compensation are 0 regardless
of the object setting.
• When servo is OFF during speed control
The unbalanced load compensation is enabled based on 3607 hex. The dynamic friction
compensation will be 0 regardless of the object setting.
• When the Servo Is Turned ON during Position Control or Fully-closed Control
The unbalanced load compensation and the dynamic friction compensation values are held
until the first position command is input. When the position command is input, the unbalanced
load compensation is updated based on 3607 hex. Also, based on the command direction, the
dynamic friction compensation value is updated according to objects 3608 and 3609 hex.
11-9-3 Operation Example
Command speed
Time
Motor
de-energized
Motor
de-energized
Motor power supply
3607 hex
(Torque command
value offset)
Forward
Reverse
3608 hex (Forward Direction
Torque Offset)
3609 hex
(Reverse Direction
Torque Offset)