MPH-02, MPB-02, MPD-02
Drive Functions
8-57
DOK-INDRV*-MP*-02VRS**-FK01-EN-P
Precision Axis Error Correction
The precision axis error correction is used for correcting non-linear
encoder errors and non-linear errors of the mechanical system. The
correction acts on the encoder selected by means of P-0-0413.
Pertinent parameters:
•
P-0-0408, Axis correction start position
•
P-0-0409, Axis correction end position
•
P-0-0410, Axis correction support point distance
•
P-0-0411, Axis correction, correction table positive
•
P-0-0412, Axis correction, correction table negative
By means of the tables
P-0-0411, Axis correction, correction table
positive
and
P-0-0412, Axis correction, correction table negative
it is
possible to enter position- and direction-dependent correction values, so-
called correction support points, within the correction range.
The correction range is within the range of values limited by the
parameters
P-0-0408, Axis correction start position
and
P-0-0409,
Axis correction end position
. The start position (P-0-0408) is preset by
the user, the end position (P-0-0409) is determined on the drive side from
the maximum value of the correction table support points used (from
P-0-0411 and P-0-0412) and the support point distance (P-0-0410).
The positions at which the correction support points are registered are
determined via the parameters
P-0-0410, Axis correction support point
distance
and
P-0-0408, Axis correction start position
. Between the
correction support points the correction values are calculated by cubic
spline interpolation.
The actual position values of the encoder selected via P-0-0413 are
corrected with the interpolated values of "correction table positive"
(P-0-0411) or "correction table negative" (P-0-0412), taking the direction
of motion into account. Positive or negative direction of motion is
detected, when
•
in the case of position control, the time-related change of position
command value (corresponding to velocity feedforward value in the
case of lagless position control),
•
in the case of velocity control, the velocity command value (S-0-0036)
has exceeded the absolute value of the standstill window (S-0-0124) in
positive or negative direction. In this case, the standstill window acts as
hysteresis, too!
The precision axis error correction is active, when a value greater than
zero was entered in parameter
P-0-0410, Axis correction support point
distance
and the position data reference was established for the encoder
the actual position value of which is to be corrected.
Correction Values
Correction Range
Correction Support Points
Activating the Precision Axis
Error Correction
Courtesy
of
CMA/Flodyne/Hydradyne
▪
Motion
Control
▪
Hydraulic
▪
Pneumatic
▪
Electrical
▪
Mechanical
▪
(800)
426-5480
▪
www.cmafh.com