| Author |
Message |
Guest
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 Posted:
Thu Mar 24, 2005 1:10 pm Post subject:
10m-10cm distance measurement with 1cm accuracy at a rate of |
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Do you know any small size, light weight distance sensor with the following
specs;
* Range : 10cm to 1000cm (10meter )
* Rate : 50 Hz (50 measurements/sec)
* Accuracy : 1cm
* Must operate on any surface (except transparent surfaces like glass)
* Power requirement : Less than 5W
* Weight : Lighter than 500grams
* Vibrartion sensitivity : Must operate 0-500Hz
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mlw
Guest
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| Posted:
Thu Mar 24, 2005 10:10 pm Post subject:
Re: 10m-10cm distance measurement with 1cm accuracy at a rat |
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<Yugo> wrote:
| Quote: | Do you know any small size, light weight distance sensor with the
following specs;
* Range : 10cm to 1000cm (10meter )
* Rate : 50 Hz (50 measurements/sec)
* Accuracy : 1cm
* Must operate on any surface (except transparent surfaces like glass)
* Power requirement : Less than 5W
* Weight : Lighter than 500grams
* Vibrartion sensitivity : Must operate 0-500Hz
|
Interesting criteria
Speed of sound is about 340 meters per second, if you want a range of 10
meters, that is a round trip of 20 meters. 340 meters per second / 20
meters round trip, that means a theoretical maximum of about 17 readings
per second, and a practical max of about 10.
Unless you can alter your specifications, SONAR is out of the question and
you'll have to use rangning RADAR.
Ranging RADAR is expensive because, unlike police speed traps which use
dopler frequency shift on the bounced return signal, a ranging radar
system, like a ranging sonar system, needs to measure between send and
recieve. Where sound travels at a pokey 240 meters per second and can be
easily measered, light travels a little less than 300,000,000 meters per
second, and requires some real precision to measure. Especially at the cm
to 10 meter range. |
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Vidar Løkken
Guest
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| Posted:
Thu Mar 24, 2005 10:10 pm Post subject:
Re: 10m-10cm distance measurement with 1cm accuracy at a rat |
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Yugo wrote:
| Quote: | Do you know any small size, light weight distance sensor with the following
specs;
* Range : 10cm to 1000cm (10meter )
* Rate : 50 Hz (50 measurements/sec)
* Accuracy : 1cm
* Must operate on any surface (except transparent surfaces like glass)
* Power requirement : Less than 5W
* Weight : Lighter than 500grams
* Vibrartion sensitivity : Must operate 0-500Hz
|
No, but I guess they excist. You could use RADAR, simply send out sound,
and see how long time it takes for it to return (knowing sound travels
more or less 300m/s. This would make it dependent on the altitude, but
it'd be easier to make with a microcontroller than light/radio based
RADAR, since light would require really really good timing...
--
MVH,
Vidar
www.bitsex.net
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quietguy
Guest
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| Posted:
Fri Mar 25, 2005 4:10 am Post subject:
Re: 10m-10cm distance measurement with 1cm accuracy at a rat |
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What about the samll commercial distance measuring units they sell at builders
shops? Cheap and easy to get, But I dont know about the specs
David
| Quote: | Yugo wrote:
Do you know any small size, light weight distance sensor with the following
specs;
* Range : 10cm to 1000cm (10meter )
* Rate : 50 Hz (50 measurements/sec)
* Accuracy : 1cm
* Must operate on any surface (except transparent surfaces like glass)
* Power requirement : Less than 5W
* Weight : Lighter than 500grams
* Vibrartion sensitivity : Must operate 0-500Hz
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Rob
Guest
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| Posted:
Fri Mar 25, 2005 7:10 am Post subject:
Re: 10m-10cm distance measurement with 1cm accuracy at a rat |
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<Yugo> wrote in message
news:4242a351$0$29448$afc38c87@news.optusnet.com.au...
| Quote: | Do you know any small size, light weight distance sensor with the
following
specs;
* Range : 10cm to 1000cm (10meter )
* Rate : 50 Hz (50 measurements/sec)
* Accuracy : 1cm
* Must operate on any surface (except transparent surfaces like glass)
* Power requirement : Less than 5W
* Weight : Lighter than 500grams
* Vibrartion sensitivity : Must operate 0-500Hz
|
Yugo - I don't know if the range or all other constraints are satisfied, but
you may want to have a look at the Sharp ranging modules, IR based IIRC.
Have a look on the Manuco website.
rob
http://www.manuco.com.au/ |
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Robert Baer
Guest
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| Posted:
Fri Mar 25, 2005 10:10 am Post subject:
Re: 10m-10cm distance measurement with 1cm accuracy at a rat |
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Vidar Løkken wrote:
| Quote: | Yugo wrote:
Do you know any small size, light weight distance sensor with the
following specs;
* Range : 10cm to 1000cm (10meter )
* Rate : 50 Hz (50 measurements/sec)
* Accuracy : 1cm
* Must operate on any surface (except transparent surfaces like
glass)
* Power requirement : Less than 5W
* Weight : Lighter than 500grams
* Vibrartion sensitivity : Must operate 0-500Hz
No, but I guess they excist. You could use RADAR, simply send out sound,
and see how long time it takes for it to return (knowing sound travels
more or less 300m/s. This would make it dependent on the altitude, but
it'd be easier to make with a microcontroller than light/radio based
RADAR, since light would require really really good timing...
|
Use of light or radio pulses (as in RADAR) is just as easy as use of
sound pulses; timing is easy.
Been around since the 1940's. |
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mlw
Guest
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| Posted:
Fri Mar 25, 2005 1:10 pm Post subject:
Re: 10m-10cm distance measurement with 1cm accuracy at a rat |
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Robert Baer wrote:
| Quote: | Vidar Løkken wrote:
Yugo wrote:
Do you know any small size, light weight distance sensor with the
following specs;
* Range : 10cm to 1000cm (10meter )
* Rate : 50 Hz (50 measurements/sec)
* Accuracy : 1cm
* Must operate on any surface (except transparent surfaces like
glass)
* Power requirement : Less than 5W
* Weight : Lighter than 500grams
* Vibrartion sensitivity : Must operate 0-500Hz
No, but I guess they excist. You could use RADAR, simply send out sound,
and see how long time it takes for it to return (knowing sound travels
more or less 300m/s. This would make it dependent on the altitude, but
it'd be easier to make with a microcontroller than light/radio based
RADAR, since light would require really really good timing...
Use of light or radio pulses (as in RADAR) is just as easy as use of
sound pulses; timing is easy.
Been around since the 1940's.
|
Ranging radar is very much more difficult than dopler radar. Dopler radar is
fairly easy to do, $100 bucks or so -- hell you can buy dopler radar off
the net to measure your pitching speed.
Ranging radar has to emit a pulse and measure the time delay from transmit
and recieve. With SONAR, this is dist = (340/2)/T (we divide by two because
echo is a two way trip), well in the millisecond range. With RADAR this is
dist = (300000000/2)/T. If you are measuing meters you are in the nano
second range. If you are trying to measure centimeters you are in the pico
second range.
This is not to say it can't be done, but it would be very expensive. |
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Deep Reset
Guest
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| Posted:
Fri Mar 25, 2005 3:55 pm Post subject:
Re: 10m-10cm distance measurement with 1cm accuracy at a rat |
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"Vidar Løkken" <njus@vidarlo.net> wrote in message
news:X_E0e.3993$4c.506280@juliett.dax.net...
| Quote: | Yugo wrote:
Do you know any small size, light weight distance sensor with the
following specs;
* Range : 10cm to 1000cm (10meter )
* Rate : 50 Hz (50 measurements/sec)
* Accuracy : 1cm
* Must operate on any surface (except transparent surfaces like
glass)
* Power requirement : Less than 5W
* Weight : Lighter than 500grams
* Vibrartion sensitivity : Must operate 0-500Hz
No, but I guess they excist. You could use RADAR, simply send out sound,
and see how long time it takes for it to return (knowing sound travels
more or less 300m/s. This would make it dependent on the altitude, but
it'd be easier to make with a microcontroller than light/radio based
RADAR, since light would require really really good timing...
You can't meet the 50Hz requirement at maximum range with sound in air, the |
best you could get would be about 16Hz.
(assuming 330 metres/second)
Deep. |
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the Artist Formerly Known
Guest
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| Posted:
Fri Mar 25, 2005 4:10 pm Post subject:
Re: 10m-10cm distance measurement with 1cm accuracy at a rat |
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Yugo wrote:
| Quote: | Do you know any small size, light weight distance sensor with the following
specs;
* Range : 10cm to 1000cm (10meter )
* Rate : 50 Hz (50 measurements/sec)
* Accuracy : 1cm
* Must operate on any surface (except transparent surfaces like glass)
* Power requirement : Less than 5W
* Weight : Lighter than 500grams
* Vibrartion sensitivity : Must operate 0-500Hz
Check into the SICK laser rangers. Not cheap, though. |
--
(Replies: cleanse my address of the Mark of the Beast!)
Teleoperate a roving mobile robot from the web:
http://www.swampgas.com/robotics/rover.html
Coauthor with Dennis Clark of "Building Robot Drive Trains".
Buy several copies today! |
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Guest
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| Posted:
Sat Mar 26, 2005 4:10 am Post subject:
Re: 10m-10cm distance measurement with 1cm accuracy at a rat |
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Leica has a few hand-held laser distance devices that seem close to
your specs.
http://www.leica-geosystems.com/cpd/en/products/laser_distancemeter
Below is some data about their higher end system. But they also have a
cheaper version that has the similar measurement abilities.
==========The Leica DISTO™ plus is the only device in the world that offers the
highest accuracy, attractive design and wireless data transfer by means
of BLUETOOTH® in one package. Even if you are currently still working
with paper and pencil, integrated BLUETOOTH® technology allows you to
make the change at any time and to record your values electronically.
The data can be transferred on site wireless to a PDA (Pocket PC) or
directly to a laptop and easily used for other purposes.
Range of measurement: 0.2 up to 200 m
(0.7 up to 650ft). Accuracy: ±1.5mm
(0.06in)
==========
Regarding price; I looked at a similar system by another vendor a few
years back and it was around $800 at the time.
Joe Dunfee |
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Stef Mientki
Guest
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| Posted:
Sat Mar 26, 2005 7:10 pm Post subject:
Re: 10m-10cm distance measurement with 1cm accuracy at a rat |
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Deep Reset wrote:
| Quote: | "Vidar Løkken" <njus@vidarlo.net> wrote in message
news:X_E0e.3993$4c.506280@juliett.dax.net...
Yugo wrote:
Do you know any small size, light weight distance sensor with the
following specs;
* Range : 10cm to 1000cm (10meter )
* Rate : 50 Hz (50 measurements/sec)
* Accuracy : 1cm
* Must operate on any surface (except transparent surfaces like
glass)
* Power requirement : Less than 5W
* Weight : Lighter than 500grams
* Vibrartion sensitivity : Must operate 0-500Hz
No, but I guess they excist. You could use RADAR, simply send out sound,
and see how long time it takes for it to return (knowing sound travels
more or less 300m/s. This would make it dependent on the altitude, but
it'd be easier to make with a microcontroller than light/radio based
RADAR, since light would require really really good timing...
You can't meet the 50Hz requirement at maximum range with sound in air, the
best you could get would be about 16Hz.
(assuming 330 metres/second)
No, you can get higher, ... |
.... why wait until a pulse is received ?
Ok next thing to do is "modulate" the pulses,
for example,
send a puls
send a second puls 10 msec later
next puls 15 msec later
next puls 12 msec later
By now combining the results of multiple measurements,
you can avoid the ambiguity.
A more diffcult way is to use continuous wave (of course modulated)
ultrasound.
Stef Mientki
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mlw
Guest
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| Posted:
Sat Mar 26, 2005 7:10 pm Post subject:
Re: 10m-10cm distance measurement with 1cm accuracy at a rat |
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Stef Mientki wrote:
| Quote: | Deep Reset wrote:
"Vidar Løkken" <njus@vidarlo.net> wrote in message
news:X_E0e.3993$4c.506280@juliett.dax.net...
Yugo wrote:
Do you know any small size, light weight distance sensor with the
following specs;
* Range : 10cm to 1000cm (10meter )
* Rate : 50 Hz (50 measurements/sec)
* Accuracy : 1cm
* Must operate on any surface (except transparent surfaces like
glass)
* Power requirement : Less than 5W
* Weight : Lighter than 500grams
* Vibrartion sensitivity : Must operate 0-500Hz
No, but I guess they excist. You could use RADAR, simply send out sound,
and see how long time it takes for it to return (knowing sound travels
more or less 300m/s. This would make it dependent on the altitude, but
it'd be easier to make with a microcontroller than light/radio based
RADAR, since light would require really really good timing...
You can't meet the 50Hz requirement at maximum range with sound in air,
the best you could get would be about 16Hz.
(assuming 330 metres/second)
No, you can get higher, ...
... why wait until a pulse is received ?
Ok next thing to do is "modulate" the pulses,
for example,
send a puls
send a second puls 10 msec later
next puls 15 msec later
next puls 12 msec later
By now combining the results of multiple measurements,
you can avoid the ambiguity.
|
How do you differentiate between pulses? What about echos from multiple
surfaces at different distences? |
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steve
Guest
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| Posted:
Tue Mar 29, 2005 4:10 pm Post subject:
Re: 10m-10cm distance measurement with 1cm accuracy at a rat |
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Try the Sharp GP2D12 sensors.
Steve
<Yugo> schreef in bericht
news:4242a351$0$29448$afc38c87@news.optusnet.com.au...
| Quote: | Do you know any small size, light weight distance sensor with the
following specs;
* Range : 10cm to 1000cm (10meter )
* Rate : 50 Hz (50 measurements/sec)
* Accuracy : 1cm
* Must operate on any surface (except transparent surfaces like glass)
* Power requirement : Less than 5W
* Weight : Lighter than 500grams
* Vibrartion sensitivity : Must operate 0-500Hz
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Acceed See
Guest
|
| Posted:
Wed Mar 30, 2005 10:10 am Post subject:
Re: 10m-10cm distance measurement with 1cm accuracy at a rat |
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===========
The Leica DISTOT plus is the only device in the world that offers the
highest accuracy, attractive design and wireless data transfer by means
of BLUETOOTH® in one package. Even if you are currently still working
with paper and pencil, integrated BLUETOOTH® technology allows you to
make the change at any time and to record your values electronically.
The data can be transferred on site wireless to a PDA (Pocket PC) or
directly to a laptop and easily used for other purposes.
Range of measurement: 0.2 up to 200 m
(0.7 up to 650ft). Accuracy: ±1.5mm
(0.06in)
===========
What is the theory behind laser ranging?
Thanks. |
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Thread Ender
Guest
|
| Posted:
Wed Mar 30, 2005 7:10 pm Post subject:
Re: 10m-10cm distance measurement with 1cm accuracy at a rat |
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| Quote: | ===========
The Leica DISTOT plus is the only device in the world that offers the
highest accuracy, attractive design and wireless data transfer by means
of BLUETOOTH® in one package. Even if you are currently still working
with paper and pencil, integrated BLUETOOTH® technology allows you to
make the change at any time and to record your values electronically.
The data can be transferred on site wireless to a PDA (Pocket PC) or
directly to a laptop and easily used for other purposes.
Range of measurement: 0.2 up to 200 m
(0.7 up to 650ft). Accuracy: ±1.5mm
(0.06in)
===========
What is the theory behind laser ranging?
Time of flight. Just like sonar, but MUCH faster. |
--TE |
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