1FFLASER_DEADSPOTS(1) Fawkes Manual FFLASER_DEADSPOTS(1)
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6 fflaser_deadspots - Calibrate dead spots for the Fawkes laser plugin
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9 fflaser_deadspots [-r host[:port]] [-w sec] [-n N] [-c dist]
10 [-m margin_deg] [-d] [-b] num spots
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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.
18 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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32 -h
33 Show usage instructions.
34 -r host[:port]]
36 The host and port of the Fawkes instance to connect to.
37 -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.
43 -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.
48 -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.
53 -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].
60 -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.
64 -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.
71 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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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.
81 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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89 fawkes(8)
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92 Written by Tim Niemueller <niemueller@kbsg.rwth-aachen.de>
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95 Documentation by Tim Niemueller <niemueller@kbsg.rwth-aachen.de>
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98 Part of the Fawkes Robot Software Framework. Project website is at
99 http://www.fawkesrobotics.org
100Fawkes 1.3.0 06/21/2022 FFLASER_DEADSPOTS(1)