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Sensor for detecting a person — Parallax Forums

Sensor for detecting a person

HemaHema Posts: 5
edited 2014-02-16 15:12 in Accessories
Hi,
I want to detect a person(not in motion) who is standing in front of a door(lets say) using sensor. It will be very helpful for me if anyone suggest me which sensor can do this. I came across PIR sensors, but they detect when the person is in motion. Quick response is appreciated.
Thank you

Regards,
Hema

Comments

  • LeonLeon Posts: 7,620
    edited 2014-01-20 03:49
    I developed the first working version of this system:

    http://www.irisys.co.uk/people-counting
  • HemaHema Posts: 5
    edited 2014-01-21 02:01
    will it detect the presence of the stationary human only or both human in motion as well as stationary ?
  • LeonLeon Posts: 7,620
    edited 2014-01-21 02:24
    IIRC (it was a long time ago) it detects stationary people, as well as people in motion. The sensor is a 16x16 array, with 256 levels for each element.
  • HemaHema Posts: 5
    edited 2014-01-21 03:08
    can you please share with me how you have done ... what is the sensor that you have used?
  • LeonLeon Posts: 7,620
    edited 2014-01-21 03:16
    I designed a board incorporating the sensor array, an FPGA, and an Analog Devices 16-bit DSP. The FPGA was designed by someone else. I ported people counter software that had been developed on a PC to the DSP, and got it working.

    IRISYS designed their own sensor array. AFAIK, they don't just sell the sensor, it is only available as part of of a system. It has to be used with a suitable germanium lens.
  • xanatosxanatos Posts: 1,120
    edited 2014-02-13 06:24
    This may be of use here: http://www.digikey.com/product-highlights/us/en/omron-d6t-thermal-sensor/2745

    I'm ordering a couple for my home automation system so the lights don't out if I'm not flailing about :)

    Dave
  • prof_brainoprof_braino Posts: 4,313
    edited 2014-02-13 17:20
    Hema wrote: »
    Hi,
    I want to detect a person(not in motion) who is standing in front of a door(lets say) using sensor. It will be very helpful for me if anyone suggest me which sensor can do this. I came across PIR sensors, but they detect when the person is in motion. Quick response is appreciated.
    Thank you

    Regards,
    Hema

    If you just want to detect a person in a doorwall, could you use a simple ultrasonic sensor? Seems a ping or sr04 would be cheapest and simplest
  • localrogerlocalroger Posts: 3,451
    edited 2014-02-15 13:25
    The sensors used to automatically open doors in buildings are ultrasonic. As prof_braino suggests a Ping should repurpose for this nicely.
  • T ChapT Chap Posts: 4,217
    edited 2014-02-15 14:53
    Sorry, the Ping is not practical for this purpose. I have installed quite a few of them for this purpose only to replace them later with radar, active IR or PIR. Ping is good when you have a predictable reflective surface. Clothing can completely negate the Pings effectiveness. I now use a sensor made by BEA called the IXIO-DT1 that has both radar and Active infrared. For a simpler cheaper concept, the PIR at Parallax does a nice job and is only 10.00. I will order that digikey link part on Monday, that looks interesting.
  • Beau SchwabeBeau Schwabe Posts: 6,557
    edited 2014-02-15 15:48
    Since the average person is 5 to 6 feet tall, I wonder if you could use them literally as an antenna capacitively coupled to an insulated plate on the floor. ... just a thought
  • xanatosxanatos Posts: 1,120
    edited 2014-02-15 16:02
    This is getting complicated... :) First - Hema, are you still reading this thread?

    Next, I posted a link above, http://www.digikey.com/product-highlights/us/en/omron-d6t-thermal-sensor/2745 - that is a second generation PIR sensor that detects people that are both in motion AND stationary. These are fantastic devices. While they do not distinguish between a human and a dog, for example, by themselves, a very little bit of creative programming can make them do so.

    I became interested in these devices because I have had the experience of being in a room where they used Gen 1 PIR sensors... and after a minute or two of my sitting with relatively little motion, it suddenly switched off the lights!

    These sensors do not do that. They remain aware of warm sources in their field of view, and you can do a lot with that data. Available in a 4 x 4 matrix, or a 1 x 16 linear configuration, you can figure just about any field of vision you need.

    Check out the link at http://www.digikey.com/product-highlights/us/en/omron-d6t-thermal-sensor/2745 and see if you might find these useful. At $50 a pop, they are NOT cheap, but they are effective and the time saved in figuring out some sort of other scheme vs. just using these fantastic little devices, may be worth the investment.

    Anyway - are you even still reading? :)

    Dave
  • prof_brainoprof_braino Posts: 4,313
    edited 2014-02-15 19:59
    Beau Schwabe (Parallax) wrote: »
    Since the average person is 5 to 6 feet tall, I wonder if you could use them literally as an antenna capacitively coupled to an insulated plate on the floor. ... just a thought

    I just flashed on using a singing telsa coil as the detector. Do you require that the person detected survive detection? Just checking.
  • Beau SchwabeBeau Schwabe Posts: 6,557
    edited 2014-02-15 20:02
    prof_braino - LOL!
  • GenetixGenetix Posts: 1,747
    edited 2014-02-16 10:04
    prof_braino wrote: »
    I just flashed on using a singing telsa coil as the detector. Do you require that the person detected survive detection? Just checking.

    Did you play Red Alert? :P
  • NWCCTVNWCCTV Posts: 3,629
    edited 2014-02-16 15:12
    Did you play Red Alert?
    Awesome game. The Tesla Coils and Mobile Tesla vehicles were the best defense/offense in the game while waiting on your nukes to be ready!!!!!!
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