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From: nagle@netcom.com (John Nagle)
Subject: Re: Narrow Beam Ultrasonic Ranging?
Message-ID: <nagleD4txtA.3n@netcom.com>
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References: <3j265o$sh8@casey.nrd.ups.com> <bcollett-0203950945590001@150.209.16.10>
Date: Thu, 2 Mar 1995 20:19:58 GMT
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In article <3j265o$sh8@casey.nrd.ups.com>, nrd1lfh@nrd.ups.com (Lee
Holeva) wrote:

>> I've been asked to explore the possibility of employing an ultrasonic
>> ranging device to acquire depth profiles of packages moving
>> down a conveyor belt.  The problem with the usual ultrasonic rangers
>> is their large beam width.  Applied in the usual way, this application
>> can tolerate no more than a one inch wide beam at a stand-off
>> distance of three and one half feet.  All of the ultrasonic rangers
>> that I have seen have at least a nine inch beam at three and one
>> half feet.  Does anyone produce a narrow beam ultrasonic ranger?
>> Is such a device even possible?

     You can buy a narrow-beam ultrasonic ranger from Cybermation, in
Richmond VA.  It uses ultrasound in the megahertz range, producing a
beam only a degree or two wide.  You have to sweep it yourself, and
the limited data rate problems of ultrasonic rangers may make it
unsuitable for a high-speed conveyor system.  Cybermation makes a
heavy-duty mobile base and a whole line of accessories for it, of which
this is one.

     But the usual approach to acquiring depth profiles of objects on
a conveyor is a structured-light vision system.  Look in Modern
Materials Handling magazine for ads.

					John Nagle
