Newsgroups: comp.robotics
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From: newman@theory.TC.Cornell.EDU (Bill Newman)
Subject: Re: Looking for information about cheap gyroscope
Message-ID: <1991Jun10.143952.29101@batcomputer.tn.cornell.edu>
Keywords: gyroscope, navigation, orientation
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Date: Mon, 10 Jun 1991 14:39:52 GMT

In article <00--VV-@engin.umich.edu> feng@caen.engin.umich.edu (Liqiang Feng) writes:
>Hi, I am looking for a device that will give me the orientation measurement 
>of a mobile robot. Of course, the first thing comes into mind is the compass, 
>however, the compass suffers from the the effects of external magnetic 
>field and acceleration. Now I turn my attention to gyroscope, here the 
>problem is the cost. Does anybody know any companies making some reasonably 
>cheap gyroscope? I do not require very high accuracy, ~+-0.5 deg or even 
>a little bit larger is fine, and also I do not require very small drift 
>over time. Are there any other devices I could possibly use to get the 
>orientation information. 
>
>Thank you in advance.

_Radio_Electronics_ just ran an article on constructing an
electronic compass using Hall effect sensors.  The schematics seemed to me
(a theoretical chemistry grad student with little practical experience)
to have some errors, but the basic concept seems practical enough.  Since
the Hall effect sensors are solid state, this would eliminate any problems
with acceleration; I don't know whether you could get +-.5 degree accuracy,
though.

  Bill Newman
  newman@theory.tc.cornell.edu