You can set whether the first, the last, or all three echoes are output.
The other pulses triggered by undesirable ambient conditions are not taken into
account.
Echo 1
Echo 2
Figure 12: Without the echo filter: The device
receives unwanted echoes from ambient con‐
ditions such as rain.
Echo 1
Echo 2
Figure 13: Using the echo filter (setting: last
echo): the device screens out unwanted ech‐
oes from ambient conditions as per the set‐
tings chosen.
3.4.7.2
Median filter
This filter is suitable for excluding individual outliers from the calculation of an average
value.
The moving median filter sorts the measured values according to their size and selects
the middle value from this sequence. The values taken into consideration are defined
by a matrix, the size of which is configurable.
A 3 x 3 matrix, for example, takes into consideration 9 measured values consisting of
the distance values of a point and its two neighboring points, along with the distances
values of these points determined from the preceding and following scan. The fifth
largest measured value is outputted as the distance value.
Median calculation: 850 (lowest value) | 850 | 950 | 1,100 |
1150
(median) | 1,150
| 1,200 | 1,200 | 1,250 (highest value)
Table 4: Example: Median for scan 2 and angle 3 (3 x 3 matrix: scan 1 to 3, angle 2 to 4)
Angle (distance values)
Scan
1
2
3
4
5
…
1
0
0
850
1100
1150
…
2
0
0
950
1200
1250
…
3
0
0
850
1150
1200
…
…
…
…
…
…
…
…
Median calculation: 0 (lowest value) | 0 | 0 | 850 |
850
(median) | 950 | 1,100 |
1,150 | 1,200 (highest value)
Table 5: Example: Median for scan 2 and angle 4 (3 x 3 matrix: scan 1 to 3, angle 3 to 5)
Angle (distance values)
Scan
1
2
3
4
5
…
1
0
0
850
1100
1150
…
2
0
0
950
1200
1250
…
3
0
0
850
1150
1200
…
…
…
…
…
…
…
…
Median calculation: 850 (lowest value) | 850 | 950 | 1,100 |
1150
(median) | 1,150
| 1,200 | 1,200 | 1,250 (highest value)
3
PRODUCT DESCRIPTION
18
O P E R A T I N G I N S T R U C T I O N S | LRS4000
8026338/0000/2022-02-15 | SICK
Subject to change without notice
