D2 Drive User Guide v1.8 3. Operation Principles
HIWIN Mikrosystem Corp. 35
3.8. Error compensation
Normally, the positioning accuracy of drive is determined by the performance of encoder. But
sometimes, the encoder cannot completely meet the requirement of accuracy. In this case,
instruments with the higher level of accuracy (e.g. laser interferometer) should be applied to
measure the system error. D2 drive has one high-performance control method. It saves the
measured error data into the error map of drive, as shown in Fig. 3-13, and uses this data
during motion. By adopting the method of linear interpolation between the fixed distance, it
calculates the value of error compensation to enhance the positioning accuracy.
Fig. 3-13
The mapping effective area is determined by the index signal. The area from the index
towards positive direction is the mapping effective area; while the area from the index towards
negative direction is the area without mapping. As shown in the following figure, the mapping
effective area for non-zero home offset is the same as that for zero home offset.
A. Home offset = 0
B. Home offset = 100
Fig. 3-14
Motor D2
Feedback position
input from encoder
index
Drive coordinate = 0
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