Mitsubishi Electric MR-J4, Instruction Manual

Page: 279 / 794

6. NORMAL GAIN ADJUSTMENT
6 - 14
6.3 Auto tuning
6.3.1 Auto tuning mode
The servo amplifier has a real-time auto tuning function which estimates the machine characteristic (load to
motor inertia ratio) in real time and automatically sets the optimum gains according to that value. This
function permits ease of gain adjustment of the servo amplifier.
(1) Auto tuning mode 1
The servo amplifier is factory-set to the auto tuning mode 1.
In this mode, the load to motor inertia ratio of a machine is always estimated to set the optimum gains
automatically.
The following parameters are automatically adjusted in the auto tuning mode 1.
Parameter Symbol Name
PB06 GD2 Load to motor inertia ratio
PB07 PG1 Model loop gain
PB08 PG2 Position loop gain
PB09 VG2 Speed loop gain
PB10 VIC Speed integral compensation
POINT
The auto tuning mode 1 may not be performed properly if all of the following
conditions are not satisfied.
The acceleration/deceleration time constant to reach 2000 r/min (mm/s) is 5 s
or less.
Speed is 150 r/min (mm/s) or higher.
The load to servo motor (mass of linear servo motor's primary side or direct
drive motor) inertia ratio is 100 times or less.
The acceleration/deceleration torque is 10% or more of the rated torque.
Under operating conditions which will impose sudden disturbance torque during
acceleration/deceleration or on a machine which is extremely loose, auto tuning
may not function properly, either. In such cases, use the auto tuning mode 2 or
manual mode to make gain adjustment.
(2) Auto tuning mode 2
Use the auto tuning mode 2 when proper gain adjustment cannot be made by auto tuning mode 1. Since
the load to motor inertia ratio is not estimated in this mode, set the value of a correct load to motor
inertia ratio in [Pr. PB06].
The following parameters are automatically adjusted in the auto tuning mode 2.
Parameter Symbol Name
PB07 PG1 Model loop gain
PB08 PG2 Position loop gain
PB09 VG2 Speed loop gain
PB10 VIC Speed integral compensation