HEIDENHAIN MANUALplus 620 Technical Manual page 841

Feedback control
with following error
January 2012
Following error (also known as servo lag) is a gap that remains between the
nominal position commanded by the NC and the actual position of the axis.
Simplified representation:
The nominal position value s
position value s and the resulting difference is the following error s
actl
s = s – s
a noml actl
s = following error
a
s = nominal position value
noml
s = actual position value
actl
The following error is multiplied by the k
velocity value:
v = k · s
v a
v = nominal velocity value
noml
The control loop gain, known as the k
position control loop. You must find the optimum k
If you choose a k factor that is too large, the following error will become very
v
small. However, this can lead to oscillations.
If you choose too small a k
slowly.
For axes that are interpolated with each other, the k
prevent contour deviations.

Define the k factor in MP_kvFactor.
v
6.16 The Control Loop
for a given axis is compared with the actual
noml
factor and passed on as nominal
v
factor, defines the amplification of the
v
v
factor, the axis will move to a new position too
v
:
a
factor by trial and error.
factors must be equal to
v
841