Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!uunet!samsung!uakari.primate.wisc.edu!dali.cs.montana.edu!milton!decwrl!well.sf.ca.us!well!nagle@uunet.UU.NET
From: decwrl!well.sf.ca.us!well!nagle@uunet.UU.NET (John Nagle)
Newsgroups: sci.virtual-worlds
Subject: Re: PowerGlove ultrsonic sensors for reading goggle orientation?
Message-ID: <7991@milton.u.washington.edu>
Date: 21 Sep 90 18:25:10 GMT
References: <7806@milton.u.washington.edu>
Sender: hlab@milton.u.washington.edu
Lines: 18
Approved: hitl@hardy.u.washington.edu




>Anyone have any
>experience with crosstalk in multidimensional short range ultrasonic range 
>sensing in small spaces?
>             ron@vicorp.COM

    Yes, I've worked with such problems in robotics.  

    If you have a fixed set of "speakers" generating ultrasonic chirps,
you can have as many microphones as you want reporting position.  The
"speakers" take turns generating chirps.  If you want a position reading
every 1/30 sec, you can have each of 3 speakers generating a chirp 
every 1/90th second, or every 11ms.  This gives you a maximum working distance
of 11 feet between speaker and microphone.

                                        John Nagle