HEIDENHAIN TNC 430 PA/M - Kv Factor During Control with Following Error; Interrelation of Kv Factor, Feed Rate, and Following Error

December 2001 The Control Loop 6 – 123
k
v
factor during
control with
following error
The control loop gain, the so-called k
v
factor, defines the amplification of the
position control loop. You must find the optimum k
v
factor by trial and error.
If you select too high a k
v
factor, the following error is very small. But this can
result in oscillations.
If you choose too small a k
v
factor, the axis will move to a new position too
slowly.
For axes that are interpolated with each other, the k
v
factors must be equal to
prevent contour deviations.
7
77
7 In MP1810.x define a set of k
v
factors for operation with following error.
You can selectively increase the contour accuracy with a higher k
v
factor . This
k
v
factor is activated with the M function M105:
7
77
7 In MP1815.x define a second set of k
v
factors and activate them with M105.
M105 also influences compensation of reversal spikes during circular motion.
With M106 you can switch back to the original set of k
v
factors:
7
77
7 Enable the M functions M105/M106 with MP7440, bit 3.
Interrelation of k
v
factor, feed rate,
and following error
The following formula shows the interrelation of k
v
factor, feed rate, and
following error:
or
k
v
= loop gain [(m/min)/mm]
v
e
= rapid traverse [m/min]
s
a
= following error [mm]
MP1810.0-8 k
v
factor for operation with following error for axes 1 to 9
Input: 0.100 to 20.000 [(m/min)/mm]
MP1815.0-8 k
v
factor for operation with following error effective after
M105 for axes 1 to 9
Input: 0.100 to 20.000 [(m/min)/mm]
MP7440 Output of M functions
Format: %xxxxx
Input: Bit 3 – Switching the k
v
factors with M105/M106:
0: Function is not in effect
1: Function is effective
k
v
v
e
s
a
------=
s
a
v
e
k
v
------=