APPENDICES

MELSEC-Q

AUTO TUNING (Automatic Tuning)

Properties such as responsiveness and stability of machines driven with a servomotor are affected by changes in the inertia moment and rigidity due to changes in the machine load, etc.

This function automatically adjusts the speed loop gain and position loop gain to match the machine state, so the machine's performance can be maintained at its optimum state.

A real time automatic tuning function should be used for machines having large load fluctuations.

AUTOMATIC TRAPEZOIDAL ACCELERATION/DECELERATION

An operation in which a graph of the time and speed takes a trapezoidal shape.

Acceleration

Deceleration

Speed

Time

BACKLASH COMPENSATION

When a forward run operation changes to a reverse run operation, there is sometimes play (backlash) in the mesh of the toothed gears. This also occurs when using a worm gear. Because of this backlash, a left feed of 1m (3.28feet) carried out after a right feed of 1m

(3.28feet) will not be sufficient to return the machine to its original position. The machine cannot be positioned to its original position without an extra feed equivalent to the backlash amount. This function compensates for that backlash amount.

Forward run

Backlash

Machine

1m (3.28feet) (right feed)does not move.

BACKUP FUNCTION

Backup functions consist of the following.

1)Functions for storing the sequence program and device statuses stored in the RAM memory of the PLC CPU, so that they are not lost during power failures, etc.

2)Functions for storing the current value in absolute position compatible systems so that it is not lost during power failures, etc.

3)Functions for reading the PLC CPU data (PLC programs, parameters, positioning data, etc.) by a peripheral device when the old PLC CPU is replaced, and then write it to the new PLC CPU after the replacement is completed.

BALL SCREW

This is a type of screw, with balls lined up in the threads like ball bearings. This reduces backlash, and enables rotation with little force.

Female thread

Male thread

1m (3.28feet) (left feed)

(Left feed amount)

Backlash

Appendix - 70

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Mitsubishi Electronics QD75P Auto Tuning Automatic Tuning, Acceleration Deceleration Speed Time, Forward run Backlash