Gain Adjustment By Auto Tuning; Adjustment Method; Valid Conditions - Mitsubishi Electric MELSERVO-J2 Series Instruction Manual

9. ADJUSTMENT

9.3 Gain adjustment by auto tuning

9.3.1 Adjustment method

In the factory setting of the servo amplifier, auto tuning is valid and the response level setting is "2"
(parameter No.3 : 0104).
The initial settings provide sufficient tuning for general machines. Higher-level tuning can be provided by
adjusting the response level setting (parameter No.3) according to machine rigidity.
The following table lists guidelines for response level setting to drive systems. Choose slow response when
using a reduction gear having backlash:
Ballscrew
Rack & pinion
Timing belt
Chain
The following is how to adjust the response setting level to machine phenomena:
Actual Machine Operation
Settling time is long (Note)
Large overshoot at stop
Gear sound generated from machine
Note: Settling time indicates time from zero command pulse to servo motor stop.

9.3.2 Valid conditions

This section provides constraints on the operation pattern to enable excellent auto tuning. If the
conditions in this section cannot be satisfied, normal auto tuning may not be performed. In this case, after
executing auto tuning in operation which satisfies the conditions given in this section, make auto tuning
invalid to disallow the gain setting from being changed.
(1) Set the acceleration time (time until the preset speed is reached) to 5s or less and the acceleration/
deceleration current to 50% or more.
(2) Perform operation several times until the cumulative acceleration/deceleration time is 1s or more.
(3) Set the servo motor speed to 500r/min or more.
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Main Drive System
Direct coupling
With reduction gear
Direct coupling
With reduction gear
Direct coupling
With reduction gear
Direct coupling
With reduction gear
Ideal Machine Operation
Reduce settling time.
Reduce overshoot.
Reduce gear sound.
POINT
If the acceleration/deceleration time is long or the servo motor speed used is
only low speed, the valid conditions of auto tuning are not satisfied.
Therefore, it may result in false tuning.
In this case, after performing operation which satisfies the auto tuning
conditions, set auto tuning selection to "Not executed" (parameter No.3:
).
search engine
Fast Response Middle Response
Increase response level setting.
Decrease response level setting.
Set machine selection setting to "large friction".
Decrease response level setting.
9 - 5
Slow Response
Parameter No.3 Setting
2