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RFbeam Microwave GmbH | Schuppisstrasse 7 | CH-9016 St. Gallen | www.rfbeam.ch | K-LD2 | data sheet

09/2018 - Revision B | Page 11/20

Speed limitation and ranging

The K-LD2 features the possibility to easily filter out

slow and fast speeds by setting speed limits with the

parameters D04 & D05 over the command set. The

limits are independent of each other and can be used

stand-alone.

The whole FFT can also be divided into two speed

ranges with the parameter D06. When the speed ran-

ge threshold is set, the detection algorithm decides

in which speed range (high or low) the detection was

Figure 11: Speed limitation and ranging overview

The usage of the speed limits and the speed

range threshold makes it very easy to divide

objects into two speed classes

found and latches it to the detection register or, if it is

configured to signal the speed range (see parameter

S06), to the miscellaneous output.

Micro detection

The micro detection is a feature to detect very slow

speeds in short range applications. It takes advantage

of an algorithm that analyses the DC bin of the FFT to

detect very slow speeds. The micro detection is inde-

pendent from the normal detection algorithm and al-

ways enabled.

If a slow movement generates a signal magnitude

that is higher than the adjustable micro detection th-

reshold (see parameter D07) the micro detection flag

in the detection register goes to high (see parameter

R00).

The miscellaneous output can be configured to si-

gnal the micro detection over the parameter S06. This

gives the host the possibility to directly trigger to a valid

micro detection.

Furthermore, it is possible to retrigger the detection

algorithm over the micro detection feature (see para-

meter S0D). If this feature is enabled, the detection al-

gorithm first requires a valid detection and then, if there

was a valid micro detection, it will retrigger the hold

time. If the hold time has elapsed because there was

no detection or micro detection, the detection goes to

low and needs again a valid detection before the micro

detection is used to retrigger the hold time.

The algorithm computes the micro detection

flag for every sampled frame, independent of

the hold time setting.

The covered speed range that is analysed by

the micro detection feature depends on the

sampling rate (see parameter S04), because

the content of the DC bin changes with the

sampling rate.