Bosch Rexroth IndraDrive MPH-02 Functional Description page 494

8-62
Drive Functions
actual position value
act. temperature
refer. temperature
P-0-0407, Temp. factor
Position-Independent
Temperature Factor
Calculating the Value
Measuring the Value
Operating principle of position-independent temperature correction:
position-indep.
Fig. 8-44: Position-independent temperature correction
Drive-internal determination of the correction value:
Xk:
P-0-0407:
P-0-0405:
P-0-0402:
Fig. 8-45: Determining the correction value
The value for P-0-0407, Axis correction temperature factor pos.-
independent
measurement.
If all data for the formula below can be unequivocally assigned due to the
assembly of the mechanical system, the correction factor can be
calculated.
P-0-0407:
α:
L
:material length the temperature expansion of which has to be
ref.temp
Fig. 8-46: Calculating P-0-0407
α
: e.g. 0.000018
(default scaling)
L
: e.g. 100mm (preferred scaling)
ref.temp
Fig. 8-47: Example for calculating P-0-0407
If it is impossible to calculate the value for P-0-0407 (e.g. if the object of
correction consists of different materials), it has to be measured. A series
of measurements determines the actual position value error of the object
of correction at different temperatures. Depending on the temperature
difference, a straight line can be approximated by means of the
measuring points.
act. pos. val., corrected
corr. value internal
x = P-0-0407 * (P-0-0405 - P-0-0402)
k
correction value, temperature-dependent
axis correction temperature factor pos.-independent
axis correction actual temperature pos.-independent
axis correction reference temperature
can be determined by means
= α
P - 0 - 0407
axis correction temperature factor pos.-independent
Linear expansion coefficient of the material
compensated (at reference temperature)
= α
P - - 0 0407 * L
ref.temp
=
0.000018
=
0.00018 mm/0.1K
1
/ , if temperature scaling °C
K
MPH-02, MPB-02, MPD-02
of calculation
* L
ref.temp
1/K * 100 mm
DOK-INDRV*-MP*-02VRS**-FK01-EN-P
or