arbotix_sensors: sensors.py Source File

00001 #!/usr/bin/env python
00002 
00003 """
00004   sensors.py - various conversions from raw analog to sensor range
00005   Copyright (c) 2011 Vanadium Labs LLC.  All right reserved.
00006 
00007   Redistribution and use in source and binary forms, with or without
00008   modification, are permitted provided that the following conditions are met:
00009       * Redistributions of source code must retain the above copyright
00010         notice, this list of conditions and the following disclaimer.
00011       * Redistributions in binary form must reproduce the above copyright
00012         notice, this list of conditions and the following disclaimer in the
00013         documentation and/or other materials provided with the distribution.
00014       * Neither the name of Vanadium Labs LLC nor the names of its 
00015         contributors may be used to endorse or promote products derived 
00016         from this software without specific prior written permission.
00017   
00018   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
00019   ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
00020   WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
00021   DISCLAIMED. IN NO EVENT SHALL VANADIUM LABS BE LIABLE FOR ANY DIRECT, INDIRECT,
00022   INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
00023   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
00024   OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
00025   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
00026   OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
00027   ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00028 """
00029 
00030 from sensor_msgs.msg import Range
00031 
00032 class SharpIR:
00033     radiation_type = Range.INFRARED
00034     field_of_view = 0.001
00035     min_range = 0.0
00036     max_range = 1.0
00037 
00038     def convert(self, raw):
00039         """ Convert raw analog (10-bit) to distance. """
00040         return raw
00041 
00042 class gpA710YK(SharpIR):
00043     """ Ultra long-range Sharp IR sensor. """
00044     min_range = 0.75
00045     max_range = 5.50
00046 
00047     def convert(self, raw):
00048         """ Convert raw analog (10-bit) to distance. """
00049         if raw > 100:
00050             return (497.0/(raw-56))
00051         else:
00052             return self.max_range+0.1
00053         
00054 class gpA02YK(SharpIR):
00055     min_range = 0.20
00056     max_range = 1.50
00057 
00058     def convert(self, raw):
00059         """ Convert raw analog (10-bit) to distance. """
00060         if raw > 80:
00061             return (115.0/(raw-12))
00062         else:
00063             return self.max_range+0.1
00064 
00065 class gp2d12(SharpIR):
00066     """ The typical GP2D12 IR ranger. """
00067     min_range = 0.10
00068     max_range = 0.80
00069 
00070     def convert(self, raw):
00071         """ Convert raw analog (10-bit) to distance. """
00072         if raw > 40:
00073             return (52.0/(raw-12))
00074         else:
00075             return self.max_range+0.1
00076 
00077 class maxSonar():
00078     radiation_type = Range.ULTRASOUND
00079     field_of_view = 0.785398163
00080     min_range = 0.0
00081     max_range = 6.4516 
00082 
00083     def convert(self, raw):
00084         """ Convert raw analog (10-bit) to distance. """
00085         return 12.7 * (raw/1024.0)
00086