Newsgroups: comp.robotics
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From: isi@world.std.com (Intelligent Solutions)
Subject: Re: Measuring distance by ultrasonic
Message-ID: <CvxvEM.Kuo@world.std.com>
Organization: The World Public Access UNIX, Brookline, MA
References: <34pmgr$11ei@rs1-hrz.uni-duisburg.de> <34rr8k$m3l@hemp.imel.kyoto-u.ac.jp> <Cvx387.13L@cunews.carleton.ca>
Date: Sun, 11 Sep 1994 00:15:57 GMT
Lines: 31

jbright@schoolnet (Jason Bright) writes:

>: Ultrasonic sensors are not too bad, but you must be aware that
>: they do not find obstacles all of the time. First of all, they are not
>: so good at detecting fabric covered soft material, because, obviously
>: these absorb the incoming signal, and not much of an echo is reflected.
>: Second, if you use the same transducer for both transmitting and 
>: receiving the pulse, then very smooth and hard surfaces can present
>: a problem. The high frequency signal is too directive, so if you do not 
>: send the pulse at a right angle, it bounces off in a different direction.

>: If these problems are OK for you, you can start off with kits available,
>: the most popular being the one from Polaroid, a device which
>: can give a digital readout, and also easily interfaced with a
>: microprocessor.

>Any idea where one would get information about these kits?


The Polaroid Developers Kit is available from Polaroid.  Technical 
assistance 1-800-225-1618, ordering 1-800-225-1000.

A simpler system using a Polaroid transducer is available from MicroMint 
Inc.  (203)871-6170.

You should also check out the FAQ for this group - lots of info.

Jim Maddox	Intelligent Solutions Inc.



