Sensor for Human detection

Discussion in 'General Electronics Chat' started by rabhishek91, Mar 30, 2013.

  1. rabhishek91

    Thread Starter Member

    Feb 14, 2013
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    Hi everyone.:)

    My latest project includes detecting whether the person is seated or not(in automobiles). This can be done by using a pressure sensor or just by a micro switch.

    Suppose i'll keep something heavy on the seat. Then the sensor detects it as a true condition and gives the output. But actually no one(Human being) is seated .
    As a solution to this problem i need to detect the presence of human along with the weight .

    This can be done by using image processing methods but i don't want to complicate my project . Is there any other sensor or a way which would help me in detecting the presence of human?
     
  2. MrChips

    Moderator

    Oct 2, 2009
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    Use a pressure sensor. There are literally thousands available.
     
  3. rabhishek91

    Thread Starter Member

    Feb 14, 2013
    51
    1
    Thanks for your reply.
    Pressure sensor detects the weight but how to confirm that whether it is a human or some non living thing ?
     
  4. PackratKing

    Well-Known Member

    Jul 13, 2008
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    Cobble up a series/parallel circuit with your pressure sensor for weight, and a temperature sensor... A non-human load, will not have the 98.6° heat signature, and will not cause your circuit to respond as if there was a person there...
    The real fun, will be calibrating to fool the circuit on a hot India summer day..... :D
     
  5. rabhishek91

    Thread Starter Member

    Feb 14, 2013
    51
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    Absolutely right sir. I was thinking about it. Thank you.
    But I think it is not so feasible to tell the occupants to wear temperature sensor when they are seated (in Automobiles).
    What's your opinion sir ?
     
  6. PackratKing

    Well-Known Member

    Jul 13, 2008
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    I wasn't thinking of something the passenger would wear.. it would be part of the circuit, and " passive "
    On the hot summer day thought, a person sitting in the seat, would cause a sun-drenched - say - 120 degree seat, to reduce to human temp, which would confirm it to be a person, and not hot sunlight...

    Good luck engineering that one ...
     
  7. rabhishek91

    Thread Starter Member

    Feb 14, 2013
    51
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    Sir Did you mean placing the temperature sensor on the seat ?
    Cheapest temperature sensor it know is LM 35(IC). So it should be in contact with the passenger if ii is place on the seat. Wouldn't it poke the passenger ?
     
  8. shortbus

    AAC Fanatic!

    Sep 30, 2009
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    How about two pressure sensors in series? One in the seat cushion, and another in the seat back. That way both sensors would be active when a person was present. If just an object was present only one would be made.
     
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  9. PackratKing

    Well-Known Member

    Jul 13, 2008
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    Not necessarily... My major concern, is how long would the heat sensor be allowed to react to the change in temperature... from sunlight to a person ?
    There are components available that would react rather quickly, then again I do not know what components are available to you there...

    On a side note.... always impressed by technology... Here I sit , talking to someone halfway around the globe...:D
     
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  10. rabhishek91

    Thread Starter Member

    Feb 14, 2013
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    Thank you sir. :)
    That's a good idea.
     
  11. rabhishek91

    Thread Starter Member

    Feb 14, 2013
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    Yes sir. I'll agree with you.Use of temperature sensor may over complicate the plot.
     
  12. PackratKing

    Well-Known Member

    Jul 13, 2008
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    That would work, in theory... one possible exception would be like my own situation.. I do contract work, and often carry a tall and heavy toolbox belted into my pickups passenger seat... Which is likely what has my airbag idiot-light on constantly... :rolleyes:
     
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  13. rabhishek91

    Thread Starter Member

    Feb 14, 2013
    51
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    Oh. Thanks for the info sir.:)
    I'll think about alternatives. If i find one it's well and good else i'll go with 2 pressure sensors cause "Something is better than nothing".
     
  14. #12

    Expert

    Nov 30, 2010
    16,261
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    Interesting. You are trying to make one of the dozens of micro controllers in a car less of a nuisance, or as we call it, less stupid, useless, waste of my time, money, and resources. Americans have already figured out that they should just fasten the seat belt around the beer (toolbox) in the passenger seat. Still, that is a stupid sensor making extra work for people. Most people can't even find the beeper, and if they could, they would be afraid to push some mud into it or break it off. I very much agree with your goal but I began by imagining a Star Wars array that could detect body temperature, heart beat, at least an outline of a moving image that can be recognized as having arms and legs. Good luck to you, sir. I hope you can do image recognition for $2 so my next car does not cost an extra $20,000 for the technology to turn off a stupid beeper.
     
  15. rabhishek91

    Thread Starter Member

    Feb 14, 2013
    51
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    Thanks for your suggestion sir. My main motto is to make use of seat belt mandatory. So this was a part of that project. I know it's difficult to implement in real-time but i'll try my best:)
     
  16. #12

    Expert

    Nov 30, 2010
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    Every part of my country already has laws that make use of seat belt mandatory. As I see it, trying to get a car to enforce the law is the cause of the problem, not the solution. Now that we have had cars trying to enforce the law for years, I sincerely wish you good results at a good price as there is no hope that this "progress" will ever not be in our private possessions (cars).
     
  17. rabhishek91

    Thread Starter Member

    Feb 14, 2013
    51
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    Sir here in INDIA the same rules exists..
    But,hardly 5% of the people follow it (i have some statistics about it)and the law here is not strict as in US(not even 20% of US). So i thought of doing this project.
    Anyways. Thank you.
     
  18. #12

    Expert

    Nov 30, 2010
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    And Thank You, too. I heartily approve of sensors that do not cause more difficulties for the law abiding citizen. (Cause as many as you want for the scofflaws.)
     
  19. Neosec

    Member

    Feb 25, 2013
    36
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    People tend to be dynamic, moving, shifting, leaning, etc. an inanimate object is static. I would think multiple pressure sensors in the seat could tell the difference. Not sensing the presence of weight so much as sensing a dynamic weight (mass).
     
  20. rabhishek91

    Thread Starter Member

    Feb 14, 2013
    51
    1
    Yes. Sensing at multiple points would be accurate. Thank you.
     
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