Siemens SINUMERIK 840 User Manual page 31

1 Introduction
1.6.2 Averaging
Effects:
• The greater k, the slower the formula reacts when major deviations occur in computation
or counter correction, however, at the same time random scatter is reduced with
increasing k.
• The smaller k, the faster the formula reacts when major deviations occur in computation or
counter correction, however, the greater the effect of random variations.
• The average value Av is calculated from 0 onwards over the number of workpieces i, until
the calculated average value exceeds the range of "Zero offset" (R33). From this limit
onwards, the calculated average value is corrected.
Example: Average value generation
1st measurement
2nd measurement
3rd measurement
4th measurement
5th measurement
6th measurement
7th measurement
8th measurement
9th measurement
10th measurement
D
5
4
3
2
3
1
1 2 3 4
Fig. 1.20 Computational variation of average values with two different weightings k
1–22
Lower limit = 4 µm
Average
D
i
value
k=3
3 µm
1 µm
5 µm
2.33 µm
6 µm
3.55 µm
2 µm
3.03 µm
4 µm
3.26 µm
5 µm
3.84 µm
4.23 µm
5 µm
1
3 µm
1 µm
7 µm
3 µm
7 µm 4.33 µm
2
1
5
4
5 6 7 8 9
Number of averaging operations (workpieces)
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Siemens AG 1990 All Rights Reserved
Average
value
k=2
1.5 µm
3.25 µm
4.62 µm
3
1 µm
2.5 µm
3.75 µm
4.375 µm
4
1.5 µm
4.25 µm
5
3.5 µm
Set/actual
difference
R 33
2
i
10
6FC5197- AB70
SINUMERIK 840/850/880 (BN)
10.91
k=2
k=3