Siemens SINUMERIK 840D sl Programming Manual page 42

General
1.9 Measuring strategy for measuring workpieces with tool offset
• The greater the value of k, the slower the formula will respond when major deviations
• The lower the value of k, the faster the formula will react when major deviations occur in
• The mean value Mi is calculated starting at 0 over the number of workpieces i, until the
• Once the mean value has been used for the offset, it is deleted from the memory. The
Table 1-2
1.
Measurement
2.
Measurement
3.
Measurement
4.
Measurement
5.
Measurement
6.
Measurement
7.
Measurement
8.
Measurement
9.
Measurement
10.
Measurement
In the measurements with marked fields, tool compensation is performed with the mean
value (calculated mean value >_TZL):
• If k=3 in the 7th and 10th measurement (① and ②),
• If k=2 in the 3rd, 7th, and 9th meas. (③, ④ and ⑤).
1-26
occur in computation or counter compensation. At the same time, however, accidental
scatter will be reduced as k increases.
computation or counter compensation. However, the effect of accidental variations will be
that much greater.
calculated mean value exceeds the range of "zero compensation"(cycle parameter _TZL,
see Chapter 2). From this limit on, the calculated mean value is applied as an offset.
next measurement then starts again with Miold = 0.
Example of mean value calculation and offset
Lower limit = 40 µm
(_TZL = 0.04)
i Di
[µm]
30
50
60
20
40
50
50
30
70
70
Mi Mi
k = 3 k = 2
[µm] [µm]
10 15
23,3 32,5
35,5 46,2 ③
30,3 10
32,6 25
38,4 37,5
42,3 ① 43,75 ④
10 15
30 42,5 ⑤
43,3 ② 35
Programming Manual, Release 04/2006, 6FC5398-4BP10-0BA0
Measuring cycles