Mitsubishi Electric A800 Plus Series Function Manual page 78

Tension PI gain tuning
• The limit cycle method is used to perform tension PI gain tuning.
• In the limit cycle method, the manipulated amount is output ten times in square waves using the actual system. Gain is
calculated from the commanded amplitude (M), vibration amplitude (Xc), and vibration cycle (Tc).
• The PI gain calculation result is automatically applied to the relevant parameter.
Before performing tension PI gain tuning
• Tension PI gain tuning can be performed when the system is stopped, or while the system is in operation.
• Tension PI gain tuning while the system is in operation is performed if the response is still slow after the tension PI gain
tuning at a system stop is performed.
Tuning method
Tension PI gain tuning during stopping
Tension PI gain tuning during operation
NOTE
• Tension PI gain tuning during stopping is not available under Real sensorless vector control. Perform the operation under the
control method other than Real sensorless vector control.
• After tension PID gain tuning is completed normally, the settings of the PID constant parameters (Pr.129 and Pr.130) are
automatically changed. Before performing tension PI gain tuning, save the PID constant parameter settings as required.
• During tension PI gain tuning, set Pr.131 PID upper limit, Pr.132 PID lower limit, Pr.553 PID deviation limit according to
the system.
• The tuning result varies depending on the winding diameter because of the different inertia. If the PID control gain response
level is slow when the winding diameter and the inertia values are large, set a large value in Pr.820 Speed control P gain 1.
• When offline auto tuning and tension PI gain tuning are attempted at the same time, offline auto tuning is performed. A setting
error occurs for tension PI gain tuning.
• When online auto tuning at startup and offline auto tuning are attempted at the same time, online auto tuning at startup is
performed first, and then offline auto tuning is performed.
Procedure of tension PI gain tuning (during stopping)
1
Tuning preparation
Fix the shafts other than the target shaft for tension PI gain tuning so that the workpiece does not move.
Check that forward/reverse operation of the target shaft causes no problem.
2
Parameter setting
Set the following parameters for tension PI gain tuning. Start setting of Pr.1222 with the smallest value (1%).
Gradually increase the value as required.
Pr.
73 Analog input selection
646 Stored winding diameter
1219 Tension PI gain tuning start/status
1222 Target amplitude
3
Starting tuning
Enter the start command to start the test operation. Check the behaviors of the workpiece and the motor.
The inverter output is shut off after the tuning is completed. As a proof of normal completion, the Pr.1219 setting
changes to "3".
As required, perform tension PI gain tuning while the system is in operation.
Check the accelerating/decelerating operation or the operation with different winding diameters, and adjust the
response level as required.
Pr.
1226 Tension PI gain tuning response level setting
Automatic tuning of the PI gain
Tuning for increasing the accuracy, to be performed if the response is still slow after the PI
gain tuning during stopping is performed.
Name
10 to 17 (Polarity reversible operation enabled.)
(For the details of Pr.73, refer to the FR-A800 Instruction Manual (Detailed).)
When the initial winding diameter calculation is invalid, set the winding
diameter value.
1 (Tension PI gain tuning starts.)
1%
Name
DANCER FEEDBACK SPEED CONTROL
Dancer feedback speed control details
Purpose
Setting
3
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