Newsgroups: comp.robotics
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From: nagle@netcom.com (John Nagle)
Subject: Re: Two axis attitude sensor
Message-ID: <nagleD3rnBq.Apn@netcom.com>
Organization: NETCOM On-line Communication Services (408 261-4700 guest)
References: <1995Feb9.162056.2074@sydrd15.tplrd.tpl.oz.au>
Date: Fri, 10 Feb 1995 04:04:38 GMT
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Sender: nagle@netcom8.netcom.com

arasv@tplrd.tpl.oz.au (Aras Vaichas) writes:
>Imagine if you had an old large(ish) trackball with an eccentrically
>weighted ball. Connect the pulsing sensors to clock over a binary
>counter, and use logic to control the up/down by sensing the
>quadrature.

      Pendulums tend to oscillate.  This is annoying.

      The good approach for a two axis attitude sensor is a 
sealed liquid unit with capacitive sensing plates.  Use a liquid
with a viscosity chosen to make the system critically damped.  These
are simple and reliable.

      Surplus units of this type can be found inside the Bosch rate
gyro units at Haltek Electronics in Mountain View, CA.

					John Nagle
