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Author Topic: Ultrasonic beam narrowing  (Read 1950 times)

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Offline benjiTopic starter

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Ultrasonic beam narrowing
« on: November 21, 2007, 10:28:02 AM »
hey guys ,, the subject says it all,
anyone can help me with narrowing that stupid 30 degrees beam?
i need to use this for mapping so i cant tolerate that much of angle spreading.
i also wouldnt want to use sharp-IRs cuz they dont provide you good ranges
the laser rangers also are incredibly expensive.
HELPPP
ive read that some people used the sonars for mapping but they didnt tell how they overcame this problem of beam spreading out..

thanks for any answers
good ol' BeNNy

Offline bens

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Re: Ultrasonic beam narrowing
« Reply #1 on: November 21, 2007, 12:15:00 PM »
From a purely theoretical standpoint, you could narrow the beam by placing a narrow, sonar-absorbing tube on the sonar receiver.  Any sound that makes it back to the detector will have come from that narrow region defined by the tube (all other signals will be absorbed before they reach the detector).

Offline Rebelgium

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Re: Ultrasonic beam narrowing
« Reply #2 on: November 21, 2007, 01:15:26 PM »
but from a practical standpoint there is a big possibility that the sonar sound will reflect against whatever tube or such you placed in front of it, and thus giving incorrect readings.
So you'll have to make sure this doesn't happen by using a tube that wide enough.
But if you use a wide tube, there will only be enough narrowing if it is a relatively long tube (15 cm or so ).

I have no experience with this problem though, this is just intuition...
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Offline Steve Joblin

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Re: Ultrasonic beam narrowing
« Reply #3 on: November 21, 2007, 07:11:29 PM »
Don't the new Maxbotix series offer what you are looking for?  http://www.maxbotix.com/MaxbotixHome.html


 


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