1FFLASER_DEADSPOTS(1)             Fawkes Manual            FFLASER_DEADSPOTS(1)
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NAME

6       fflaser_deadspots - Calibrate dead spots for the Fawkes laser plugin
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SYNOPSIS

9       fflaser_deadspots [-r host[:port]] [-w sec] [-n N] [-c dist]
10                         [-m margin_deg] [-d] [-b] num spots
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DESCRIPTION

13       This tool is used to calibrate dead spots for spinning laser scanners.
14       If a laser scanner is mounted, sometimes not the whole field of view
15       can be used, because mounting of other hardware requires brackets or
16       poles, creating regions where laser data is useless and generally
17       short, i.e. dead spots.
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19       This tool reads laser data from the blackboard for a given number of
20       cycles, and thresholds it based on a given distance. It records a given
21       number of data sets and compares the threshold to the median of each
22       beam. Any laser beam that is shorted than the given distance is
23       considered to be in a dead spot. After registering all short beams,
24       adjacent beams are accumulated to dead spot regions. The configuration
25       information is then written to the configuration of the connected
26       Fawkes instance for later use (unless a dry run is performed). To
27       prevent false calibration the number of expected dead spots can be
28       supplied, to detect if there was not enough free space around the robot
29       during calibration.
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OPTIONS

32       -h
33           Show usage instructions.
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35       -r host[:port]]
36           The host and port of the Fawkes instance to connect to.
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38       -w sec
39           Wait the given time in seconds before acquiring the data. This
40           gives some time for last preparations, like removing a cable. The
41           maximum wait time is 60 seconds, the default wait time is 10
42           seconds.
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44       -n N
45           The number of measurements to use to calculate the median of the
46           laser beam distance value to compare to the threshold. The default
47           number of measurements is 100.
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49       -c dist
50           The threshold distance. Laser beams below this distance are
51           considered dead, longer once are good. The default threshold
52           distance is 0.9 meters.
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54       -m margin_deg
55           Add an extra margin of margin_deg to each calculated dead spots, on
56           both sides. Dead spots, that overlap after applying the margin are
57           merged. The margin can be negative to shrink the regions. The
58           margin is given in degrees as integer with a value range of
59           [-359..359].
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61       -d
62           Do a dry run, i.e. do not write the calibration information to the
63           configuration file but only print it to the console.
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65       -b
66           Write a fake laser scan to the blackboard interface
67           "Laser720Interface::Laser Calibration", with "good" values having a
68           distance of 1.0, and dead values a distance of 0. This allows for a
69           quick inspection if the result matches the expectation. Stop
70           showing the data with Ctrl-C when done.
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72       num spots
73           Expect to have N dead spots. If a different number of dead spots is
74           found abort and report an error.
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EXAMPLES

77       fflaser_deadspots 4
78           Read measurements from Fawkes on localhost, calculate dead spots
79           with the default values and expect 4 dead spots. Write the data
80           back to the configuration when successful.
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82       fflaser_deadspots -w 5 -n 200 -c 1.5 -m 1 -d 3
83           Run the calibration, based on 200 measurements and a distance
84           threshold of 1.5 meters, after waiting 5 seconds. Add a margin of 1
85           degree to calculated spots, expect 3 dead spots. Do not write data
86           to the configuration (perform a dry run).
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SEE ALSO

89       fawkes(8)
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AUTHOR

92       Written by Tim Niemueller <niemueller@kbsg.rwth-aachen.de>
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DOCUMENTATION

95       Documentation by Tim Niemueller <niemueller@kbsg.rwth-aachen.de>
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FAWKES

98       Part of the Fawkes Robot Software Framework. Project website is at
99       http://www.fawkesrobotics.org
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103Fawkes 1.3.0                      06/21/2022              FFLASER_DEADSPOTS(1)
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