User manual

9 Functions and operations in the position control mode
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Gain tuning mode
• Automatic
Set the mechanical rigidity using the mechanical rigidity setting switch (SW2) on the driver or the application
parameter for mechanical rigidity setting [APP-0-02].
Which value should be made effective is selected using the application parameter for mechanical rigidity
setting switch [APP-4-00].
Once the mechanical rigidity is set, the gain will be adjusted automatically.
Refer to p.68 for details on the range of gains that can be set with automatic tuning.
SW2 dial
setting
Value of mechanical rigidity
setting switch parameter
Reference mechanical rigidity
0 to 3 0 to 3 Low rigidity (belt pulley, etc.)
4 to 9 4 to 9 Medium rigidity (chain, etc.)
A to F 10 to 15 High rigidity (ball screw, directly coupled load, etc.)
Note
• The higher the value of mechanical rigidity, the higher the motor response becomes.
Note, however, that an excessively high value may cause vibration or noise.
• The estimated value of load inertial moment is saved in the driver’s EEPROM every
20 minutes.
• Semi-auto
1.
Set the application parameter for load inertial moment ratio [APP-0-01].
The load inertial moment ratio refers to the percentage of the inertial moment of the load to the rotor
inertial moment of the motor. If the rotor inertial moment is equal to the load inertial moment, the load
inertial moment ratio becomes 100%. Refer to the catalog for the rotor inertial moment of your motor.
If the equipment is complex and estimating the load is difficult, you can use the OPX-2A or MEXE02
to monitor the load inertial moment ratio estimated by the driver.
2.
Set the mechanical rigidity in the same manner as in the “automatic” mode.
Once the mechanical rigidity and load inertial moment ratio are set, the gain will be adjusted
automatically.
Refer to p.68 for details on the range of gains that can be set with semi-auto tuning.
• Manual
Follow the procedure below to adjust the gain with a sufficient margin.
1.
Set the application parameter for load inertial moment ratio [APP-0-01].
The load inertial moment ratio refers to the percentage of the inertial moment of the load to the rotor
inertial moment of the motor. If the rotor inertial moment is equal to the load inertial moment, the load
inertial moment ratio becomes 100%. Refer to the catalog for the rotor inertial moment of your motor.
If the equipment is complex and estimating the load is difficult, you can use the OPX-2A or MEXE02
to monitor the load inertial moment ratio estimated by the driver.
2.
Set the mechanical rigidity in the same manner as in the “automatic” mode.
3.
Adjust the compliance with respect to speed deviation. Set the application parameter for speed
loop gain [APP-0-04].
Increasing the speed loop gain will decrease the deviation between the command speed and actual speed.
Note, however, that an excessively high value may increase the motor overshoot or cause hunting.
4.
Decrease the deviation that cannot be adjusted with the speed loop gain. Set the application
parameter for speed loop integral time constant [APP-0-05].
If the integral time constant is too high, motor operation will become slow. If the constant is too low, on
the other hand, hunting may occur.
5.
Adjust the compliance with respect to position deviation. Set the application parameter for
position loop gain [APP-0-03].
Increasing the position loop gain will decrease the deviation between the command position and actual
position. Note, however, that an excessively high value may increase the motor overshoot or cause
hunting.
6.
Repeat steps 2 to 5 to set an optimal gain.