Mitsubishi Electric MELSERVO-J4 series, Instruction Manual

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17 APPLICATION OF FUNCTIONS
17.5 Machine diagnosis function
Total travel distance failure prediction function
Use the total travel distance failure prediction function with the following procedure.
Friction vibration estimation function
• If the vibration frequency is extremely low or high, vibration estimation cannot be performed. For example, a
low frequency vibration of several tens of hertz is generated with a machine of low rigidity. Note that such a
frequency cannot be detected.
• If the equipment vibrates at a plurality of frequencies simultaneously due to some mechanical resonance or
others, vibration frequency may not be estimated properly.
• Vibration frequency may not be estimated properly under the condition that the torque crosses the torque
limit value. Set a longer acceleration time and deceleration time, or slightly decrease the gains to prevent
the occurrence of excessive torque vibrations.
• It is recommended to save the values estimated by the friction vibration estimation function at the start of
operation. The degree of machine degradation after operation can be checked by comparing the value
estimated by the friction vibration estimation function after operation and the value at the start of operation,
facilitating preventive maintenance.
In the friction vibration estimation function, the friction estimation function estimates the friction of the drive system in the
equipment, and the vibration estimation function estimates the minute vibration level and vibration frequency based on the
data in the servo amplifier. The friction estimation function estimates and detects the static friction (including gravity) of a
guide and ball screw and the dynamic friction coefficient after operation is performed in any operation pattern. The vibration
estimation function estimates and detects the vibration level both during servo motor operation and at a servo motor stop, and
vibration frequency both during servo motor operation and at a servo motor stop after operation is performed in any operation
pattern.
Start
Start the system. (Refer to chapter 4.)
Set "Servo motor total travel distance failure
prediction warning selection (_ x _ _)" in
[Pr. PF34] to "_ 1 _ _ (manual threshold setting)".
Drive the servo motor.
Set "Failure prediction - Servo motor total travel
distance multiplication selection (x _ _ _)" in
[Pr. PF34] and [Pr. PF41 Failure prediction - Servo
motor total travel distance] based on the rated life.
Total travel distance failure prediction is performed.
When the servo motor total travel distance exceeds
the servo motor total travel distance for failure
prediction, [AL. F7.3 Total travel distance failure
prediction warning] will occur.
End