SICK IVP Ranger E/D

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Operating Instructions Chapter 3

Ranger E/D

Overview

For each measured point, the range value that the Ranger returns represents the number

of rows – or vertical pixels – from the bottom or top of the ROI to where it detected the

laser line.

If the Ranger was unable to locate the laser line for a point – for example due to insuffi-

cient exposure, that the laser line was hidden from view, or that the laser line appeared

outside of the ROI – the Ranger will return the value 0. This is usually referred to as miss-

ing data.

In addition to the range values, all components except Horizontal threshold also deliver

intensity values for the measured points along the laser line. The intensity values are the

maximum intensity in each column of the sensor, which – in the normal case – is the

intensity of the reflected laser line.

Figure 3.5 – Different methods for determining the range by analyzing the light intensity

in each column of the sensor image:

Threshold determines the range by locating intensities above a certain level,

while Max locates the maximum intensity in each column.

The resolution in the measurements depends on which component that is used. For

example the Horizontal max and threshold method returns the location of the laser line

with ½ pixel resolution, while the High-res 3D method has a resolution of

/16

of a pixel.

Note that the actual range values from the Ranger depends on the used resolution – for

example if the Ranger is configured to measure with ½ pixel resolution, the returned range

values are the number of ½-pixels from the bottom or top of the ROI.

Besides the measurement method, the resolution in the measurements depends on how

the Ranger and the laser are mounted, as well as the distance to the object. For more

information on how the resolution is affected by how the Ranger is mounted, see chapter

“Mounting Rangers and Lightings” in the Reference manual.

Rows

Columns

Intensity

Threshold

Sensor image

Rows

Intensity

Max

Columns

Rows

Threshold Max

Columns

Projected

laser line

SICK IVP Ranger E/D - Page 17