MPH-02, MPB-02, MPD-02
Drive Functions
8-65
DOK-INDRV*-MP*-02VRS**-FK01-EN-P
When the position data reference was established for the actual position
value system, the correction value related to the current actual position
value is drive-internally determined as follows:
x
k
= (S-0-0051/53 - P-0-0403) * (P-0-0404 - P-0-0402) * P-0-0406
Xk:
correction value, temperature- and position-dependent
S-0-0051/53: actual position value encoder 1 or encoder 2
P-0-0402:
axis correction reference temperature
P-0-0403:
axis correction reference position for temp. corr.
P-0-0404:
axis correction actual temperature pos.-dependent
P-0-0406:
axis correction temperature factor pos.-dependent
Fig. 8-52:
Determining the correction value, temperature- and position-
dependent
For position-dependent temperature correction there is an axis position
that is not invalidated by variations of temperature. It is the reference
position for position-dependent temperature correction and is entered in
parameter
P-0-0403, Axis correction reference position for temp.
corr
.
Determining the reference position by:
•
direct measurement, if the arrangement of the mechanical
transmission elements allows unequivocally recognizing the reference
position
- or -
•
a series of measurements with which the actual position value error is
measured at axis positions clearly different from the reference position
(at constant temperature that is clearly different from the reference
temperature (P-0-0402))
As in the majority of cases it is impossible to determine the reference
point by direct measurement, determining the reference point by means of
a series of measurements is of great importance.
reference position (x
0
)
correction value (x
k
)
machine zero point
actual pos.
value (x
act
)
P
1
(x
act1
,x
k1
)
P
2
(x
act2
,x
k2
)
P
3
(x
act3
,x
k3
)
x
k3
x
k2
x
k1
x
act3
x
act2
x
act1
Fig. 8-53:
Illustration of the reference position
By means of the measuring points (P
1
, P
2
, P
3
) it is possible to determine
the reference position by the equation of an approximated straight line:
a
b
x
−
=
0
x
0
:
reference position
b:
intersection point of straight line and correction value axis (x
k
)
a:
gradient of the straight line
Fig. 8-54:
Equation for determining the reference position
Determining the Reference
Position
Reference Position by Series of
Measurements
Courtesy
of
CMA/Flodyne/Hydradyne
▪
Motion
Control
▪
Hydraulic
▪
Pneumatic
▪
Electrical
▪
Mechanical
▪
(800)
426-5480
▪
www.cmafh.com
