Newsgroups: comp.robotics
Path: brunix!uunet!tcsi.tcs.com!agate!library.ucla.edu!news.mic.ucla.edu!magnesium.club.cc.cmu.edu!cantaloupe.srv.cs.cmu.edu!crabapple.srv.cs.cmu.edu!netnews.srv.cs.cmu.edu!ssingh
From: ssingh@frc2.frc.ri.cmu.edu (Sanjiv Singh)
Subject: Re: Gyro, Compass engine
In-Reply-To: Cliff_Lum@mindlink.bc.ca's message of Sat, 7 Aug 1993 08:06:27 GMT
Message-ID: <SSINGH.93Aug9100749@wilbur.frc.ri.cmu.edu>
Sender: news@cs.cmu.edu (Usenet News System)
Nntp-Posting-Host: wilbur.frc.ri.cmu.edu
Reply-To: ssingh@ri.cmu.edu (Sanjiv Singh)
Organization: Field Robotics Center
References: <27522@mindlink.bc.ca>
Date: Mon, 9 Aug 1993 14:07:49 GMT
Lines: 27


We have one of the KVH compasses in house and I recently tested it for
usage on an indoor mobile robot.  I found it to be utterly useless
since it is affected by changes in magnetic flux.  Inside a building,
you can not hope for this to give any modicum of accuracy.  Throw in
some computer terminals and power supplies and it gets worse. 

I talked to the KVH rep in NJ.  He claims that one solution would be
to mount it about 2 feet above the robot (on top of an antenna).
He mentioned that some military tanks mount the KVH units in this
fashion. For indoor appications, raising the compass two feet made no
difference because the interference is coming from the world not the
robot.

I suspect the compass will work much better outdoors. Watch out
though, if you are experimenting in a parking lot, and you go by a
large metal dumpster. We had this problem during early runs on the 
Navlab, when we were also using a magnetic compass.


	
--
------------------------------------------------------------------------
Sanjiv Singh                                    ssingh@ri.cmu.edu
Field Robotics Center                           (412) 268-5895
Carnegie Mellon University
-----------------------------------------------------------------------
