Activation Of Master-Slave Torque Control; Setting The Master-Slave Torque Control For Minimizing Mechanical Play - HEIDENHAIN TNC 426 PB/M Technical Manual

Activation of
master-slave
torque control
Setting the master-
slave torque control
for minimizing
mechanical play
6 – 94
7 7 7 7 Activate the master and slave axes with MP10.
7 7 7 7 In MP110.x, define the position encoder for the master.
7 7 7 7 Enter MP110.x = 0 for the slave.
7 7 7 7 In MP850.x, define the master axis as the main axis and the slave axis as
the tracking axis.
7 7 7 7
Activate the master-slave torque control by entering MP860.x = 2 for the
slave axis.
MP860.0-8 Datum for synchronization control for axes 1 to 9
Input: 2: Axis is torque slave axis
7 7 7 7 For the master and slave axes you must select in MP1040 the same or the
opposite direction of rotation, depending on the application (MP210 has no
effect on the slave).
7 7 7 7 Adjust the current controller for the master and slave axes (See
"Commissioning" on page 6 – 462).
7 7 7 7
Enter the following temporary values in the machine parameters for the
slave axis:
MP2900.x = approx. 20% to 25% of the rated torque of the motor
MP2910.x = 3
MP2930.x = 0
7 7 7 7 In MP2920.x, enter the ratio of the mass moment of inertia of the master to
the mass moment of inertia of the slave. For identical motors, therefore, the
value to be entered is 1.
7 7 7 7
If you use a position encoder, in MP2930.x enter 100 for the slave axis; if
you do not use a position encoder, enter the value 0.
7 7 7 7 Enter MP2510.x (I factor of speed controller) = 50 or, if you have one, an
empirical value for your motor.
7 7 7 7 Adjust the P and I factor of the speed controller for the master and slave
axes at the same time (See "Commissioning" on page 6 – 462). It is not
permissible to commission the master and slave axes separately, since the
motors must be tensioned during commissioning.
7 7 7 7 If you do not reach the desired rise time (approx. 10 ms), you can increase
the P factor with the aid of a filter. Here the band-rejection filter is preferable
to the low-pass filter.
7 7 7 7
To find the center frequency for the band-rejection filter, slowly increase the
P factor to the oscillation limit and find the frequency with the integrated
oscilloscope.
Note
For low-frequency oscillations (< approx. 200 Hz) you should not
use a filter, because it may have a negative influence on the dynamics of
the control. For the mid-range frequency (approx. 200 Hz to approx. 400 Hz)
ensure that you do not excite any low-frequency oscillation.
The higher the frequency of the oscillation (> approx. 400 Hz), the less
negative will be the influence of high damping on the dynamics.
Note
For identical motors, the factors of the speed controller should be identical
to ensure identical dynamic behavior.
HEIDENHAIN Technical Manual TNC 426, TNC 430