Panasonic MINAS A5-series Operating Instructions Manual page 265

5. Manual Gain Tuning (Application)
Friction torque compensation
How to Use
The friction torque compensation will be added in response to the entered positional
command direction as shown below.
Motor
de-energized
The friction compensation torque is the sum of the offset load compensation value which is set
according to the torque command additional value (always constant) and the dynamic friction
compensation torque which is set according to positive/negative direction torque compensation
value.
The command speed direction is reset upon power-up or when the motor is de-energized.
• Pr6.07 [Torque command additional value] reduces variations in positioning operation
(performance is affected by direction of movement). These variations occur when con-
stant offset torque resulting from weight on vertical axis is applied to the motor.
• Certain loads such as belt driven shaft requires high dynamic friction torque, which
lengthens positioning setting time or varies positioning accuracy. These problems can
be minimized by setting the friction torque of every rotating direction into individual pa-
rameters. Pr6.08 [Positive direction torque compensation value] and Pr6.09 [Negative
direction torque compensation value] can be used for this purpose.
Caution
The offset load compensation and dynamic friction compensation can be used individu-
ally or in combination. However, some control modes impose limit on application.
• For torque control: Offset load compensation and dynamic friction compensation are set
at 0 regardless of parameter setting.
• For velocity control with servo-off: Offset load compensation per Pr6.07 is enabled. Dy-
namic friction compensation is set at 0 regardless of parameter setting.
• For position control or full closed control with servo-on: Previous offset load compensa-
tion and dynamic friction compensation values are maintained until the first positional
command is applied where the offset load compensation value is updated according to
Pr6.07. The dynamic friction compensation value is updated to parameters Pr.6.08 and
Pr6.09 depending on command direction.
Command speed
Pr6.07
[ ]
Torque command
additional value
[Positive direction]
Pr6.08
[
Positive direction torque
compensation value
[
Negative direction torque
compensation value
[Negative direction]
Motor energized
]
Pr6.09
]
Time
Motor
de-energized
5-35
1
2
3
4
5
6
7