[Lab] range finding

[Matthew Bells]

There has been some interesting research recently about tracking people
passively with Wi-Fi signals, similar to radar.

 

Sonar or radar sound the easiest from in terms of tracking the distance as a
person is moving away / towards you on a line. If the line is orthogonal to
the sensor, then using video might be easiest. You might also want to
consider hacking a cheap laser range finder, like the ones that are used to
measure rooms.

 

-Matt

 

From: Lab [mailto:lab-bounces at artengine.ca] On Behalf Of Darcy Whyte
Sent: 2014.February.05 15:20
To: Adam Hill
Cc: lab
Subject: Re: [Lab] range finding

 

I want to just track their position on a line that's about 10 or 20 feet
long. I haven't figured the distance out yet but it will be something like
that...

 

 




 

 

--

Darcy Whyte

 

Art+ inventorArtist.com <http://inventorartist.com/>  | Aviation
rubber-power.com <http://rubber-power.com/> 

Contact: darcy at inventorArtist.com | 613-563-3634 by appointment (no text)

 

 

On Wed, Feb 5, 2014 at 3:14 PM, Adam Hill <theadbo at gmail.com> wrote:

Hi Darcy,

 

I've had occasion to think about similar things over the last couple of
years. I wasn't sure what exactly you meant by '20 foot distance'. 

Do you mean track them in 3 dimensions inside a 20 ft radius? If so, then
you probably want to go with machine vision (kinect (1st gen) is probably
easier to get up and running but there are some libraries for doing this
with a webcam (not as performant)). 

 

If you mean measure a linear distance from the source to the person, or a
boolean indication of the presence of a person, up to 20ft away, then I
would say something similar to the hardware you're currently using. I would
note that in my experience these are not created equally. I like the MB1210
(http://www.abra-electronics.com/products/MB1210-Ultrasonic-Range-Finder-%25
2d-XL%252dMaxSonar%252dEZ1.html). It was the most reliable out to just less
than 20 ft, and is specifically calibrated for people detection. 

 

Good luck!

-a


On Wednesday, February 5, 2014, Darcy Whyte <darcy at inventorartist.com>
wrote:

I was just thinking. In the endgame I want to be tracking a person moving
over a 20 foot distance. 

 

I'm starting to think I might need to try something else. Ideas?




 

 

--

Darcy Whyte

 

Art+ inventorArtist.com <http://inventorartist.com/>  | Aviation
rubber-power.com <http://rubber-power.com/> 

Contact: darcy at inventorArtist.com | 613-563-3634 by appointment (no text)

 

 

On Wed, Feb 5, 2014 at 2:02 PM, Darcy Whyte <darcy at inventorartist.com>
wrote:

Hi, I have one of these (I think)
http://ramshackblog.blogspot.ca/2012/02/ultrasonic-range-finder-using-sdm-io
.html

 

It has four pins.

 

I've got it working using the code at that page. It measures really well up
to about 30cm then after that it just prints out 999 cm?

 

I noticed with a piece of paper I can get further (around 70cm). 

 

It's supposed to be good for 150cm. 

 

Any ideas what's going on here?

 

I have two of them and I tried the other one (in case it was a bu
component). But same result...

 

 

--

Darcy Whyte

 

Art+ inventorArtist.com <http://inventorartist.com/>  | Aviation
rubber-power.com <http://rubber-power.com/> 

Contact: darcy at inventorArtist.com | 613-563-3634 by appointment (no text)

 

 


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