MPH-02, MPB-02, MPD-02
Drive Control
6-23
DOK-INDRV*-MP*-02VRS**-FK01-EN-P
Determining the Commutation Offset, Calculation
Method when Using the Hall Sensor Box SHL01.1
The Hall sensor box SHL01.1 is an absolute measuring system within one
pole pair distance of a Rexroth linear motor. Via the signals of the Hall
sensors the controller detects the position of the motor windings
compared to the magnetic field of the motor.
The value for the commutation offset depends on the motor data and the
mounting distance of the box compared to the primary part. This value is
independent of the axis position and is determined once during initial
commissioning (data for mounting, connection and determination of
commutation offset see documentation on Hall sensor box SHL01.1).
Determining the Commutation Offset, Measuring Method
The measuring method for determining the commutation offset described
below can only be used for Rexroth linear motors with motor encoder that
can be evaluated in absolute form (EnDat encoder). The method is
currentless, i.e. the motor does not generate any force. At drive enable
(AF =
A
ntriebs
f
reigabe) it is then immediately fully operational.
Note:
For rotary synchronous Rexroth kit motors the commutation
offset can only be determined with methods with current
(saturation or sine-wave method) because there wasn’t any
measuring method defined!
To determine the commutation offset the relative position of the primary
part (electrically active part) must be determined with regard to the
secondary part (electrically inactive part). The distances to be measured
are depending on the axis position, the measurements described below
have to be carried out once during initial commissioning.
Depending on the possibility of accessing the primary and secondary part
in the machine or installation, the relative position of the primary and
secondary part can be measured in different ways:
d
e
f
g
l
p
1
2
3
4
secondary part(s)
LSS
power connection
DF0060v1.fh7
primary part LSP
Fig. 6-18: Measuring the relative position between primary and secondary part
Note:
After the distance has been measured the position of the
primary part mustn’t be changed any more until the
determination of the commutation offset is completed!
Application-Related Aspect
Measuring the Relative Position
Between Primary and Secondary
Part
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of
CMA/Flodyne/Hydradyne
▪
Motion
Control
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426-5480
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