RoBIOS/psd-calibrate/index.html

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   2 <HEAD>
   3 <TITLE>psd-calibrate: Calibrating the Eyebot IR distance sensors</TITLE>
   4 </HEAD>
   5 <BODY>
   6 <H1>PSD calibration package for eyebot robots</H1>
   7
   8 <H2>Current README</H2>
   9 <PRE>
  10 Calibrating the Eyebot IR distance sensors
  11 ==========================================
  12
  13 Version 0.1 by Petter Reinholdtsen &lt;pere@td.org.uit.no&gt;
  14
  15 To calibrate the IR distance sensors (PSDs) on the Eyebot, one need to
  16 update the HDT with a more correct lookup table to map raw data into
  17 distance in millimeter.
  18
  19 To get the correct lookup table, you run 'psd-calibrate.hex' on the
  20 robot to collect the correct data.  It assumes the VW drive functions
  21 are working correct.
  22
  23 Collecting is done by placing the robot directly in front of the wall,
  24 with at least 1.5 meters free space behind, and probably at least 0.5
  25 meters of free space to either side.  The front of the robot should
  26 touch the wall.  Distance is calculated from the sensors.  It is
  27 assumed that the sensors are 4.5 cm from the center of the robot
  28 (between the wheels), and it is assumed that the wall is 6 cm from
  29 this center.
  30
  31 The robot will then measure the raw values for the different sensor
  32 pointing into the wall, while moving backwards until it reaches 1
  33 meter.  The measured data is the average of 10 values collected.  When
  34 it is finished it will stop and wait for the data to be collected.
  35
  36 The data can be collected using the serial port.  Connect the robot to
  37 the computer using the serial cable.  The robot is using 115200 bps.
  38 Run 'cat &lt; /dev/ttyS0 | tee calibrate-data.raw' and press 'DUMP' on
  39 the Robot.  Check on the PC to make sure the information arrived, and
  40 press Ctrl-C to stop receiving.
  41
  42 When the datafile is saved on the PC, you can look at it using
  43 './plot-psd-calibr.sh calibrate-data.raw'.  This will show the mapping
  44 between cm (x) and raw data measured (y).
  45
  46 To make the HDT entry, run './make_hdt_map.pl calibrate-data.raw' to
  47 get the PSD lookup table in C format.  These tables need to be
  48 inserted into the HCD C file, and the robot updated with the new .hex
  49 file.  Remember to change 'distX' to the correct symbol for the given
  50 PSD.
  51
  52 Newer versions might be available from
  53 &lt;URL:http://ciips.ee.uwa.edu.au/~pere/RoBIOS/&gt;.
  54 </PRE>
  55
  56 <UL>
  57 <LI><A HREF="psd-calibrate-0.1.tar.gz">Download v0.1</A>
  58 <LI><A HREF="psd-data-graph.png">example graph</A>
  59 </UL>
  60 </BODY>
  61 </HTML>