Newsgroups: comp.robotics
Path: brunix!brunix!kjb
From: kjb@cs.brown.edu (Ken Basye)
Subject: Sonar and Bats (was: Re: My robot project status #3)
Message-ID: <1992Mar28.021516.19490@cs.brown.edu>
Sender: news@cs.brown.edu
Organization: Brown University Department of Computer Science
Date: Sat, 28 Mar 1992 02:15:16 GMT
Lines: 38


John Nagle writes:
>kilian@cray.com (Alan Kilian) writes:
>>    The module can't see the couch until it's about 6 Inches away.
>         That's right; if you want range down to 0, you need separate
>receive and transmit transducers.

I was confused about this because I thought of the robot moving *toward*
the couch, and thus thought the problem was not seeing it until it was
"as close" as 6 in., not "as far away" as 6 in.  I couldn't imagine
what find of couch material could be that sound absorbent.

>       On the sonar front, it's time for somebody who's really into audio,
>sonar, and digital signal processing to build a real sonar system that
>images.  Something at least as good as bat sonar, which is reasonably well
>understood.   

I think this would be a Very Good Thing as well, but I'd certainly
caution against selling bats short here.  James Simmons here at Brown
is an expert in the biotechnology of bat sonar.  I've read some of his
stuff and been to a talk of his; he's done a number of experiments
showing that bats have very good imaging capabilities, have entire
repertoires of out-going signal patterns for different sensing tasks,
and process incoming signals at nanosecond rates.  I know he's done
some work with the Submarine Signal Division at Raytheon.  From what
I've seen of bat sonar and our experiences here with the standard
Poloroids, if we even got halfway to the bat we'd be in fantastic
shape (especially if we could do it with only, say, 10 times the space
and power the bat uses :-).  I'll dig up references to Simmons' work
on request.

    Ken

Internet/CSnet  kjb@cs.brown.edu     U.S. MAIL  Ken Basye
UUCP            uunet!brunix!kjb                Box 1910
                                                Dept. of Computer Science
                                                Brown University
                                                Providence, RI  02912
