Absolute Position Detection System - Mitsubishi Electric MELSERVO-J3W Series Instruction Manual

13. USING A LINEAR SERVO MOTOR
(2) Auto tuning function
The auto tuning function during the linear servo operation is the same as that of normal servo, but the
calculation method of load to motor mass ratio (J ratio) is different. The load to motor mass ratio (J ratio) on
the linear servo is a mass ratio calculated dividing the load mass by the load to mass of the linear servo
motor primary side (coil) ratio.
Example) Linear servo motor primary side (coil) mass
Load mass (excluding the motor primary side (coil) mass)
Mass ratio
Refer to chapter 6, other parameters set with the auto tuning function.
(3) Machine analyzer function

13.5.7 Absolute position detection system

When using the linear servo motor for the absolute position detection system, the absolute position linear
encoder is required. The backup of absolute position data is performed by the linear encoder. For this reason,
there is no need to mount an MR-BTCASE battery case and MR-BAT battery for encoder on the servo amplifier.
Also, the alarm (25.1) and warnings (92.1, 9F.1 and E3. ) related to the absolute position are not detected.
POINT
If not meeting with the following conditions, the auto tuning mode 1 may not operate
properly.
The acceleration/deceleration time constant which takes less than 5s to reach to
2,000mm/s
The linear servo motor speed is 150mm/s or faster.
The load to mass of the linear servo motor primary side (coil) ratio is 100 times
or smaller.
The acceleration/deceleration thrust is 10
POINT
Make sure to carry out the machine analyzer function after the magnetic pole
detection. If the magnetic pole detection is not executed, the function may not
operate properly.
The stop position at the completion of machine analyzer can be any position.
13 - 35
2kg
4kg
4/2 Twice
or less of the rated thrust.