Angle (distance values in mm)
Scan
1
2
3
4
5
…
Filtered measured values
1
0
851
851
850
…
…
2
0
850
851
852
…
…
3
0
850
851
851
…
…
…
…
…
…
…
…
…
If median filters and average filters are used together, an additional time offset does
not need to be included for the median filter here either. This is because averaging
takes longer than median determination and the latter can be completed during averag‐
ing.
3.5.7.4
Average filter
The average filter smooths the distance value. It does this by calculating the arithmetic
mean from several scans of the same point. The number of scans can be configured.
Table 6: Example: Average filter over 5 scans
Angle (distance values in mm)
Scan
1
2
3
4
5
6
7
8
9
…
1
0
0 1100 1100 1150 1150 1380 1380
0
…
2
0
0 1200 1200 1190
950
1500 1500
0
…
3
0
0 1150
1450
1200 1200 1450 1450
0
…
4
0
0 1280 1280 1180 1180 1430 1430
0
…
5
0
0 1170 1170 1220 1220 1470
1150
0
…
1st output value
0
0 1180 1240 1188 1140 1446 1382
0
…
6
0
0
0
1100 1150 1150 1380 1380
0
…
7
0
0 1200 1200 1190
0
1500 1500
0
…
8
0
730
1150
0
1200 1200 1450 1450
0
…
9
0
0
0
1280 1180 1180 1430 1430
0
…
10
0
0 1170 1170 1220 1220 1470
0
0
…
2nd output value
0
730 1173 1187 1188 1187 1446 1440
0
…
…
…
…
…
…
…
…
…
…
…
…
Individual outliers (shown in
bold
in the table) influence the average value.
Once the measured value telegram has been confirmed, the first measured value is not
output until after the configured number of scans. Therefore, there is always a time
delay equivalent to the number of scans configured for averaging. The digit of the first
scan included in the averaging calculation is always output in the scan counter. Invalid
distance values (= 0) are not included in the averaging calculation, so that in these
places a smaller number of scans is used in the division calculation. The measured val‐
ues from other channels (remission, angle correction) are not averaged; instead, the
value of the first scan from each channel is output.
Based on the scanning frequency of 600 Hz, a measured value is generated every
1.67 ms. The time delay affecting data output results from this base value multiplied by
the number of averaging operations (e.g., 2 averaging operations = 3.34 ms,
10 averaging operations = 16.67 ms).
3
PRODUCT DESCRIPTION
22
O P E R A T I N G I N S T R U C T I O N S | LMS4000
8023198//2018-06-18 | SICK
Subject to change without notice