Best Sensor To Use

Hi guys,

I had a quick question. I wanted to create something that uses a sensor to sense a person's proximity to an object, i.e. a wall, and make an alarm sound. What would be the best (most accurate for this idea) sensor to use?

Thanks

LIDAR placed at the trigger distance and scanning a plane parallel to the wall.

Explain more on what you really want to achieve.

Many options. Ultrasound, IR, capacitive, etc.

Which one works best depends on at least: - how close proximity should it detect? - how big of an area to monitor? - what material is the wall made of? - is the wall flat or curved or other shape? - detect the whole person's presence or a pointing finger getting too close to the wall? Maybe more, but this off the top of my head.

Break beam parallel to the wall ?

Generally speaking, I wanted the sensor device to be able to pick up a finger or other part that is too close to a wall but also have the ability to sense slightly larger things such as birds. I had thought of it to be put on a flat wall. What is the maximum area any sensor for this could monitor? The project is just to create something that can sense movement or damage to an object.

wvmarle: Explain more on what you really want to achieve.

Many options. Ultrasound, IR, capacitive, etc.

Which one works best depends on at least: - how close proximity should it detect? - how big of an area to monitor? - what material is the wall made of? - is the wall flat or curved or other shape? - detect the whole person's presence or a pointing finger getting too close to the wall? Maybe more, but this off the top of my head.

"too close" for the finger is how close? 2 mm or 5 meters or something else? How about the birds?

ThatJellyfish04:
Hi guys,

I had a quick question. I wanted to create something that uses a sensor to sense a person’s proximity to an object, i.e. a wall, and make an alarm sound. What would be the best (most accurate for this idea) sensor to use?

Thanks

The most accurate distance sensor would be an optical interometer, having first mounted a retro-reflector
on the person to enable such a measurement. That could get you sub 100nm accuracy.

Or perhaps you mean accuracy in terms of the minimum number of false positives and false negatives,
in which case something real complex is needed like high-end CV system and AI methods of object
recognition (to discriminate people from robots for instance).

Clearly you don’t truly mean “most accurate”. You probably mean you’ve a set of requirements and desirable
features, and the more fully you list those the more likely we can help find the right sensor.

Above all you didn’t say what you are actually trying to do, so its very hard to judge suitability of
possible sensors. For it matters if this is outdoors or indoors - we have no idea of the context, and
details and context are usually key.

wvmarle: "too close" for the finger is how close? 2 mm or 5 meters or something else? How about the birds?

I guess 1/2 a meter at least and 2 meters at most.

http://xyproblem.info/

If you can describe more what it is that you're trying to accomplish then someone might be able to help better. With just vague ramblings and guesses at specifications then there's not much anyone can realistically do for you.

Might be worth stating what your project is trying to do