Bosch Rexroth IndraDrive MPH-02 Functional Description page 495

MPH-02, MPB-02, MPD-02
Calculation by Means of
Measured Values
Activating the Function
How to Use the Function
DOK-INDRV*-MP*-02VRS**-FK01-EN-P
correction value x
x
k3
x
k2
∆T
1
x
P (∆T
k1
1 1
x : correction value (measured position value – actual position value
kn
(S-0-0051/S-0-0053))
∆T
: temperature difference
n
(measured temperature – reference temperature (P-0-0402))
Fig. 8-48: Approximated straight correction line on the basis of measured
correction values at different ∆T
The gradient of the approximated straight line is the value of the position-
independent temperature factor. By means of the value from the series of
measurements it is possible to calculate the position-independent
temperature factor:
− − =
P 0 0407
P-0-0407: axis correction temperature factor pos.-independent
n: number of measured values
∆T
: temperature difference at which the correction value x
n
determined
correction value at the temperature difference ∆T
x :
kn
Fig. 8-49: Calculating the position-independent temperature factor from the
values of the series of measurements
The position-independent temperature correction is activated when the
value of P-0-0407, Axis correction temperature factor pos.-
independent is greater than zero.
Note: With the value zero in parameter P-0-0407 the function of
position-independent temperature correction is deactivated.
This correction function does not require position data
reference for the measuring system to the corrected!
Position-Dependent Temperature Correction
The position-dependent temperature correction is used to compensate for
the temperature-dependent linear expansion of the mechanical transfer
elements of a servo axis or the measuring system. Depending on the
position of the axis slide, the temperature-dependent linear expansion
causes actual position value errors of different extent over the travel
range of the axis.
At a position of the axis there is a non-temperature-dependent "point of
reference" available that is used as the reference position for the position-
dependent temperature correction.
k
P
P (∆T ,x )
2 2 k2
∆T
2
,x )
k1
∑ ∑
× ∆ × −
n ( T x )
n kn
∑ ∑
× ∆ −
n T ² (
n
8-63
Drive Functions
(∆T ,x )
3 3 k3
temperature
difference
∆T
(∆T)
3
∑
∆ ×
T x
n kn
∆
T )²
n
was
kn
n