Distance sensor 10cm-10m @50Hz

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

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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.

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.

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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.

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