Distance sensor 10cm-10m @50Hz

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

I would re-post this question on sci.electronics.design I bet you'll get
tons of responses there.

<Yugo> wrote in message
news:4242a566$0$22221$afc38c87@news.optusnet.com.au...
> 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> wrote in message
news:4242a566$0$22221$afc38c87@news.optusnet.com.au...
> 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
>
>

There are a couple of methods. First you could use an infra-red
emitter/receiver pair, but you probably won't get the accuracy you want and
the colour of the object will way too much of a difference. They are good
for a simple is less than or greater than distance x though.

The best method is probably to use an sonar type system. Take a look at
comp.robotics or comp.robotics.misc these guys tend to use the sonar modules
out of polaroid cameras to detect things in the way of their robots. Their
accuracy is pretty good. Do a google search for something like 'Polaroid
robot' and you'll get loads of hits.

Rich.

On Thu, 24 Mar 2005 19:29:51 -0000, "Richard Webb"
<webby@REMOVEMErichardwebb-online.co.uk> wrote:

><Yugo> wrote in message
>news:4242a566$0$22221$afc38c87@news.optusnet.com.au...
>> 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

> ...

>The best method is probably to use an sonar type system. Take a look at
>comp.robotics or comp.robotics.misc these guys tend to use the sonar modules

   He already posted this there, and someone already pointed out that
sound won't travel his max distance round-trip fast enough for him to
get 50 measurements per second.
   I'd suggest several ultrasonic systems at different frequencies,
but that's probably going to go over-budget on one or more of his
other items.

>out of polaroid cameras to detect things in the way of their robots. Their
>accuracy is pretty good. Do a google search for something like 'Polaroid
>robot' and you'll get loads of hits.
>
>Rich.

-----
http://mindspring.com/~benbradley

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
> 
> 

The sensor system must have some filtering of its own
to limit the maximum frequency component at the sampler
to half of the sample rate (25 Hz at 50 samples/s), or
you'll get interesting interference effects. I'm looking
at the combination of 50 samples/s and vibration range
of 0 to 500 Hz.

-- 

Tauno Voipio
tauno voipio (at) iki fi

On Fri, 25 Mar 2005 08:09:30 GMT, Tauno Voipio
<tauno.voipio@iki.fi.NOSPAM.invalid> 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
>> 
>> 
>
>The sensor system must have some filtering of its own
>to limit the maximum frequency component at the sampler
>to half of the sample rate (25 Hz at 50 samples/s), or
>you'll get interesting interference effects. I'm looking
>at the combination of 50 samples/s and vibration range
>of 0 to 500 Hz.

   Also not specified is the amplitude of the vibration, either in
spatial displacement or as acceleration in g's. Anything can operate
over that frequency range of vibration if the amplitude is low enough,
and if the amplitude is high enough, NOTHING will operate.
-----
http://mindspring.com/~benbradley