HEIDENHAIN iTNC 530 HSCI - Page 643

1 – 644 HEIDENHAIN Service Manual iTNC 530 HSCI
Position controller With the iTNC 530 HSCI the user can choose between two types of feedback control:
 Feedback control with following error (servo lag)
 Feedback control with velocity feedforward
Position feedback
control with
following error
Feedback control with following error means that there is a certain lag, i.e. a distance between the
nominal position commanded by the NC and the actual axis position.
Figure: Simplified representation of feedback control with following error
The nominal position value s
noml
for a given axis is compared with the actual position value s
actl
and
the resulting difference is the following error s
a
:
The following error is multiplied by the k
v
factor and passed on as nominal velocity value:
Machine
parameter
Following
error
Velocity
feedforward
For the operating modes
MP1391.0 0 1 Manual and handwheel
MP1392 0 1 Positioning with Manual Data Input, Program
Run Single Block, Program Run Full Sequence
Note
The machine should be adjusted for both types of control.
v
Noml
S
Noml
S
Actl
Note
Analog axes (control via CMA-H): For stationary axes, the integral factor has an additional effect
(MP1080.x). It produces an offset adjustment.
Digital axes: There is no offset. MP1080.x has no function.
s
a
=s
noml
– s
actl
s
a
= Following error
s
noml
= Nominal position value
s
actl
= Actual position value
v
noml
=k
v
· s
a
v
noml
= Nominal velocity value