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Subject: 
Re: Ultra Sonic Sensor Readings
Newsgroups: 
lugnet.robotics
Date: 
Wed, 2 May 2007 19:36:58 GMT
Viewed: 
4301 times
  
In lugnet.robotics, Edwin Pilobello wrote:

Does anyone have experimental data I can compare to?

No, but I can think of some ways to generate such data. Part of the problem is
that weather or not the sensor sees a return depends on two spread functions:
the spread of sound energy from the transmitter, and the spread fo sound energy
reflected from the object (which will vary in intensity and spread, depending on
the geometry of the situation, as well as the incident power which in turn
depends on the first spread function, etc.) Fun, huh?

I also need advice of detecting the scatter.

Don't (as in "I'm not really sure how, without some other equipment"). The idea
of using multiple US sensors to detect the ping from a single one is a good
idea, but I've yet to see any good way to do it. You *can* set an US sensor to
single-shot mode, or record multiple returns, etc. But to actually "listen" the
US sensor needs to send out a signal - it really doesn't care about the strength
of the returnedpulse, only the time lapse between them. In other words, it's not
a microphone.

What do you think?

I think if you really want to study the signal spread from the US sensor, you
need as controled a situation as possible. Look up "corner cube reflector". I
used an inside corner of 1/8 System (NOT Technic) bricks that was 8 bricks high,
and got really good results (you might want to try a smaller reflector of you
are more worried about angular resolution, but I'm not sure how small you could
get away with at various ranges).

--
Brian Davis



Message has 1 Reply:
  Re: Ultra Sonic Sensor Readings
 
(...) OK. I'll read up. At the moment, I'm staring at a midium size paper cup. I think I'll slice it in half and see how good a reflector it is. I suppose the studs on an 8x8 plate were probably acting like baffles in my last experiment. (17 years ago, 3-May-07, to lugnet.robotics)

Message is in Reply To:
  Ultra Sonic Sensor Readings
 
I've read the previous postings on the ultrasonic (aka "echo locator" among my students). I'm experimenting to see what the cone of energy looks like. Does anyone have experimental data I can compare to? I also need advice of detecting the scatter. (...) (17 years ago, 2-May-07, to lugnet.robotics)

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