Ways of measuring distance from a wall to people?

Forum 2005-2010 (read only) General Frequently-Asked Questions
1

Hi all,
I need to measure distance from a wall to several people in an empty room for an installation.

My goals are:

  • Track small changes in distance effectively (i need good measuring resolution).
  • Be able to track fast changes (i need fast reaction time)
  • The system should be ideally able to track distance to several people, not necessarily each individual, but at least groups of people.

My first thought was that it could be done using computer vision (jmyron in processing or eyesweb), but it seems that this method is very cpu-consuming, too dependent on the quality of the camera and lightning, and i doubt about the resolution i'll be able to get. Some people suggested using an ultrasonic rangefinder connected to an arduino board. I have never done anything similar, so I have lots of doubts...

  1. Have you done anything similar?
  2. Are there any other options for this task? Do you think it can be done in a better way?
  3. How difficult will it be to implement this using arduino?
  4. How do you think I should deal with the requirement of being able to track distance to several people? Would I need more than one sensor? How sensitive are them? How directional? What's the range they cover? Where can I get them?
  5. How do I connect the sensor to arduino?

I hope you can help me.

2

I'll give the ultrasonic rangefinder a go then, I can live with the fact that it will only detect the closest person. :slight_smile: