Distance Finding
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Posts: 46,084
Hi, does any one have any idea as to how robots can be built to
sense the distance between one another?
Is there any chips that would allow me to do that?
sense the distance between one another?
Is there any chips that would allow me to do that?
Comments
broadcast both a radio (RF) and audio (AF) chirp at the same time. Since RF
travels about one billion feet per second (essentially instantaneously) and
AF only about 1132 feet per second, you just count the time delay between
the RF and AF and calculate out the distance. Just like counting the seconds
between the lightening flash and thunder will tell you how far the storm is
from you.
I think if each robot broadcast a unique RF and AF frequency, you could
figure who was who and how far they're away from you. Getting exact
direction is a little trickier, but you could put three "beacons" in the
corners broadcasting on freqs A, B, and C and it would be straight logic to
triangulate your position I think.
The other guys in the group can better direct you to the proper Stamp
programs, but since I used to be a "real" robotics guy in a previous life,
that's how I would do it....
Mike Sokol
www.modernrecording.com
mikes@m...
" One should not increase, beyond what is necessary,
the number of entities required to explain anything"...
-William of Occam-
Original Message
From: "rich2kchan" <rich2kchan@y...>
To: <basicstamps@yahoogroups.com>
Sent: Friday, December 05, 2003 4:59 PM
Subject: [noparse][[/noparse]basicstamps] Distance Finding
>
> Hi, does any one have any idea as to how robots can be built to
> sense the distance between one another?
> Is there any chips that would allow me to do that?
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
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>
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>
>
You could put a single strobe light in the room pointed towards the ceiling
which would flash once a second or so. Each robot would have a photo-sensor,
microphone, and small speaker. You could also put three pylons to define the
outer border.
Each robot and pylon would be assigned a specific audio chirp frequency,
possibly the dual-tones of telephones. These frequencies have been carefully
selected by Bell Labs to avoid harmonic issues and such. As each of the
robots "saw" the strobe flash, they would chirp on their specific frequency
pair, then listen on their microphones for all the other tones to arrive. An
analog filter could trip a latch feeding an input chip which the stamp could
read every millisecond or so, then reset the latch. To get one-foot position
accuracy, you need one-millisecond resolution on timing, for one-inch
position accuracy you would need to sample the return every 100 microseconds
or so. Yes, you would need air temperature compensation if you wanted to be
really accurate, but that's small change compared to the other variations in
little systems.
Basically, you're building a mini- GPS system that uses a strobe clock
instead of satellite clocks, and the lag time of sound in air, rather than
RF lag from satellites to earth. For your mini-GPS you could substitute an
RF generator for the strobe clock, but photo-transistors and a strobe are
much cheaper than RF transmitters and receivers. Also note that strobe
lights generate a large amount of ultraviolet light, so by stacking some
theater lighting gels in front of the photo-transistor receivers you can
make it "see" only the strobe pulse.
This seems like a cool enough project to work on my boys 8th grade science
project. I haven't gone over the triangulation math in my head yet, but it
should be pretty straightforward.
Mike Sokol
www.modernrecording.com
mikes@m...
" One should not increase, beyond what is necessary,
the number of entities required to explain anything"...
-William of Occam-
Original Message
From: "rich2kchan" <rich2kchan@y...>
To: <basicstamps@yahoogroups.com>
Sent: Friday, December 05, 2003 4:59 PM
Subject: [noparse][[/noparse]basicstamps] Distance Finding
>
> Hi, does any one have any idea as to how robots can be built to
> sense the distance between one another?
> Is there any chips that would allow me to do that?
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
robot, each robot could have a specific time-slot after
the strobe appears on the ceiling in which it would "chirp".
Time Unit 1 2 3 4
Robot1 - X C
Robot2 - X C
Robot3 - X C
Robot4 - X C
X = Strobe
C = Chirp
-Beau Schwabe
>Here's another variation on distance finding...
>
>You could put a single strobe light in the room pointed towards the ceiling
>which would flash once a second or so. Each robot would have a photo-sensor,
>microphone, and small speaker. You could also put three pylons to define the
>outer border.
>
>Each robot and pylon would be assigned a specific audio chirp frequency,
>possibly the dual-tones of telephones. These frequencies have been carefully
>selected by Bell Labs to avoid harmonic issues and such. As each of the
>robots "saw" the strobe flash, they would chirp on their specific frequency
>pair, then listen on their microphones for all the other tones to arrive. An
>analog filter could trip a latch feeding an input chip which the stamp could
>read every millisecond or so, then reset the latch. To get one-foot position
>accuracy, you need one-millisecond resolution on timing, for one-inch
>position accuracy you would need to sample the return every 100 microseconds
>or so. Yes, you would need air temperature compensation if you wanted to be
>really accurate, but that's small change compared to the other variations in
>little systems.
>
>Basically, you're building a mini- GPS system that uses a strobe clock
>instead of satellite clocks, and the lag time of sound in air, rather than
>RF lag from satellites to earth. For your mini-GPS you could substitute an
>RF generator for the strobe clock, but photo-transistors and a strobe are
>much cheaper than RF transmitters and receivers. Also note that strobe
>lights generate a large amount of ultraviolet light, so by stacking some
>theater lighting gels in front of the photo-transistor receivers you can
>make it "see" only the strobe pulse.
>
>This seems like a cool enough project to work on my boys 8th grade science
>project. I haven't gone over the triangulation math in my head yet, but it
>should be pretty straightforward.
>
>Mike Sokol
>www.modernrecording.com
>mikes@m...
>
>
>" One should not increase, beyond what is necessary,
>the number of entities required to explain anything"...
>-William of Occam-
>
>
>
Original Message
>From: "rich2kchan" <rich2kchan@y...>
>To: <basicstamps@yahoogroups.com>
>Sent: Friday, December 05, 2003 4:59 PM
>Subject: [noparse][[/noparse]basicstamps] Distance Finding
>
>
> >
> > Hi, does any one have any idea as to how robots can be built to
> > sense the distance between one another?
> > Is there any chips that would allow me to do that?
> >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the Subject and
>Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
> >
> >
>
>
>
>To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
>from the same email address that you subscribed. Text in the Subject and
>Body of the message will be ignored.
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
That would work as long as you allow enough time for the maximum distance.
For instance, if you have a 100 ft by 100 ft arena, it would take something
less than 100 milliseconds for the sound to traverse it end to end. A little
longer diagonally (1.4 times that if memory serves). That means if you
waited about 150 milliseconds or so between chirps, you could still fit in 4
robots and 3 beacons with a 1.5 second strobe clock.
If so, this really makes the analog filter issue pretty simple. I would
suggest a relatively low frequency (not ultrasonic) might be usable since
beaming action of short wavelength (hi freq) audio is a problem. I think the
little electric mics from Radio Shack would be good out to 10 kHz or so, and
generating that sort of pulse omnidirectionally is possible. Perhaps a small
speaker pointing directly upwards with a cone pointing down at it would give
a 360 degree spread. Sort of like those outside patio speakers.
Mike Sokol
www.modernrecording.com
mikes@m...
" One should not increase, beyond what is necessary,
the number of entities required to explain anything"...
-William of Occam-
Original Message
From: "Beau Schwabe" <bschwabe@a...>
To: <basicstamps@yahoogroups.com>
Sent: Monday, December 08, 2003 11:15 AM
Subject: Re: [noparse][[/noparse]basicstamps] Distance Finding
> Instead of "chirps" of different frequencies between each
> robot, each robot could have a specific time-slot after
> the strobe appears on the ceiling in which it would "chirp".
>
> Time Unit 1 2 3 4
>
> Robot1 - X C
> Robot2 - X C
> Robot3 - X C
> Robot4 - X C
>
> X = Strobe
> C = Chirp
>
>
> -Beau Schwabe
>
> >Here's another variation on distance finding...
> >
> >You could put a single strobe light in the room pointed towards the
ceiling
> >which would flash once a second or so. Each robot would have a
photo-sensor,
> >microphone, and small speaker. You could also put three pylons to define
the
> >outer border.
> >
> >Each robot and pylon would be assigned a specific audio chirp frequency,
> >possibly the dual-tones of telephones. These frequencies have been
carefully
> >selected by Bell Labs to avoid harmonic issues and such. As each of the
> >robots "saw" the strobe flash, they would chirp on their specific
frequency
> >pair, then listen on their microphones for all the other tones to arrive.
An
> >analog filter could trip a latch feeding an input chip which the stamp
could
> >read every millisecond or so, then reset the latch. To get one-foot
position
> >accuracy, you need one-millisecond resolution on timing, for one-inch
> >position accuracy you would need to sample the return every 100
microseconds
> >or so. Yes, you would need air temperature compensation if you wanted to
be
> >really accurate, but that's small change compared to the other variations
in
> >little systems.
> >
> >Basically, you're building a mini- GPS system that uses a strobe clock
> >instead of satellite clocks, and the lag time of sound in air, rather
than
> >RF lag from satellites to earth. For your mini-GPS you could substitute
an
> >RF generator for the strobe clock, but photo-transistors and a strobe are
> >much cheaper than RF transmitters and receivers. Also note that strobe
> >lights generate a large amount of ultraviolet light, so by stacking some
> >theater lighting gels in front of the photo-transistor receivers you can
> >make it "see" only the strobe pulse.
> >
> >This seems like a cool enough project to work on my boys 8th grade
science
> >project. I haven't gone over the triangulation math in my head yet, but
it
> >should be pretty straightforward.
> >
> >Mike Sokol
> >www.modernrecording.com
> >mikes@m...
> >
> >
> >" One should not increase, beyond what is necessary,
> >the number of entities required to explain anything"...
> >-William of Occam-
> >
> >
> >
Original Message
> >From: "rich2kchan" <rich2kchan@y...>
> >To: <basicstamps@yahoogroups.com>
> >Sent: Friday, December 05, 2003 4:59 PM
> >Subject: [noparse][[/noparse]basicstamps] Distance Finding
> >
> >
> > >
> > > Hi, does any one have any idea as to how robots can be built to
> > > sense the distance between one another?
> > > Is there any chips that would allow me to do that?
> > >
> > >
> > >
> > > To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@yahoogroups.com
> > > from the same email address that you subscribed. Text in the Subject
and
> >Body of the message will be ignored.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> > >
> > >
> >
> >
> >
> >To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> >from the same email address that you subscribed. Text in the Subject and
> >Body of the message will be ignored.
> >
> >
> >Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
tone multiple frequency) is ok when you just have two different tones hence
the "dual", but when there are several different tones things can get real
messy. Assuming you would use bank of 567 tone decoders or notch filters to
decipher the available tones present from each robot (possibly more than 4
robots; I gave an earlier example of 4), detecting the amplitude of each tone
could be a real nightmare.
-Beau Schwabe
>Yeah....
>
>That would work as long as you allow enough time for the maximum distance.
>For instance, if you have a 100 ft by 100 ft arena, it would take something
>less than 100 milliseconds for the sound to traverse it end to end. A little
>longer diagonally (1.4 times that if memory serves). That means if you
>waited about 150 milliseconds or so between chirps, you could still fit in 4
>robots and 3 beacons with a 1.5 second strobe clock.
>
>If so, this really makes the analog filter issue pretty simple. I would
>suggest a relatively low frequency (not ultrasonic) might be usable since
>beaming action of short wavelength (hi freq) audio is a problem. I think the
>little electric mics from Radio Shack would be good out to 10 kHz or so, and
>generating that sort of pulse omnidirectionally is possible. Perhaps a small
>speaker pointing directly upwards with a cone pointing down at it would give
>a 360 degree spread. Sort of like those outside patio speakers.
>
>Mike Sokol
>www.modernrecording.com
>mikes@m...
>
>
>" One should not increase, beyond what is necessary,
>the number of entities required to explain anything"...
>-William of Occam-
>
>
>
Original Message
>From: "Beau Schwabe" <bschwabe@a...>
>To: <basicstamps@yahoogroups.com>
>Sent: Monday, December 08, 2003 11:15 AM
>Subject: Re: [noparse][[/noparse]basicstamps] Distance Finding
>
>
> > Instead of "chirps" of different frequencies between each
> > robot, each robot could have a specific time-slot after
> > the strobe appears on the ceiling in which it would "chirp".
> >
> > Time Unit 1 2 3 4
> >
> > Robot1 - X C
> > Robot2 - X C
> > Robot3 - X C
> > Robot4 - X C
> >
> > X = Strobe
> > C = Chirp
> >
> >
> > -Beau Schwabe
> >
> > >Here's another variation on distance finding...
> > >
> > >You could put a single strobe light in the room pointed towards the
>ceiling
> > >which would flash once a second or so. Each robot would have a
>photo-sensor,
> > >microphone, and small speaker. You could also put three pylons to define
>the
> > >outer border.
> > >
> > >Each robot and pylon would be assigned a specific audio chirp frequency,
> > >possibly the dual-tones of telephones. These frequencies have been
>carefully
> > >selected by Bell Labs to avoid harmonic issues and such. As each of the
> > >robots "saw" the strobe flash, they would chirp on their specific
>frequency
> > >pair, then listen on their microphones for all the other tones to arrive.
>An
> > >analog filter could trip a latch feeding an input chip which the stamp
>could
> > >read every millisecond or so, then reset the latch. To get one-foot
>position
> > >accuracy, you need one-millisecond resolution on timing, for one-inch
> > >position accuracy you would need to sample the return every 100
>microseconds
> > >or so. Yes, you would need air temperature compensation if you wanted to
>be
> > >really accurate, but that's small change compared to the other variations
>in
> > >little systems.
> > >
> > >Basically, you're building a mini- GPS system that uses a strobe clock
> > >instead of satellite clocks, and the lag time of sound in air, rather
>than
> > >RF lag from satellites to earth. For your mini-GPS you could substitute
>an
> > >RF generator for the strobe clock, but photo-transistors and a strobe are
> > >much cheaper than RF transmitters and receivers. Also note that strobe
> > >lights generate a large amount of ultraviolet light, so by stacking some
> > >theater lighting gels in front of the photo-transistor receivers you can
> > >make it "see" only the strobe pulse.
> > >
> > >This seems like a cool enough project to work on my boys 8th grade
>science
> > >project. I haven't gone over the triangulation math in my head yet, but
>it
> > >should be pretty straightforward.
> > >
> > >Mike Sokol
> > >www.modernrecording.com
> > >mikes@m...
> > >
> > >
> > >" One should not increase, beyond what is necessary,
> > >the number of entities required to explain anything"...
> > >-William of Occam-
> > >
> > >
> > >
Original Message
> > >From: "rich2kchan" <rich2kchan@y...>
> > >To: <basicstamps@yahoogroups.com>
> > >Sent: Friday, December 05, 2003 4:59 PM
> > >Subject: [noparse][[/noparse]basicstamps] Distance Finding
> > >
> > >
> > > >
> > > > Hi, does any one have any idea as to how robots can be built to
> > > > sense the distance between one another?
> > > > Is there any chips that would allow me to do that?
> > > >
> > > >
> > > >
> > > > To UNSUBSCRIBE, just send mail to:
> > > > basicstamps-unsubscribe@yahoogroups.com
> > > > from the same email address that you subscribed. Text in the Subject
>and
> > >Body of the message will be ignored.
> > > >
> > > >
> > > > Your use of Yahoo! Groups is subject to
>http://docs.yahoo.com/info/terms/
> > > >
> > > >
> > >
> > >
> > >
> > >To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@yahoogroups.com
> > >from the same email address that you subscribed. Text in the Subject and
> > >Body of the message will be ignored.
> > >
> > >
> > >Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
> >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the Subject and
>Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
> >
> >
>
>
>
>To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
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