Is there any Sensor that senses the motion in passanger lift?

Discussion in 'General Electronics Chat' started by Amey@7823, Jun 25, 2016.

  1. Amey@7823

    Thread Starter New Member

    Jun 25, 2016
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    Hi Every one.
    I am doing one project in that i need to sense the motion in the lift when it starts. I tried the accelerometer but it didn't worked. Any suggetions will be helpfull to me.


    Thanks
     
  2. DickCappels

    Moderator

    Aug 21, 2008
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    Just guessing, but maybe your best bet is to get a more sensitive accelerometer.

    Other ideas, probably not as good as the accelerometer

    • A fluxgate magnetometer could probably sense the changing ambient magnetic field as the elevator moves, particularly if there is plenty of structural steel in the building or elevator shaft.

    • A sensitive barometer might be able to tell you when the elevator's altitude changes (and probably when lots of other things happen too).

    • Use a GPS receiver and watch for changes altitude.

    • Tie a string to the ceiling of the lift shaft and watch a reel wind it in and unwind as the elevator goes up or down.

    • Use an ultrasound distance measuring setup to measure the distance to the ceiling or floor of the elevator shaft.

    • If the door does not seal tightly, the amount of light entering the elevator will change minutely when it starts to move and that can be detected.
     
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  3. MaxHeadRoom

    Expert

    Jul 18, 2013
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    What type of elevator is it, Cable lift or hydraulic cylinder?
    You can get encoders with rubber tyres that could travel on the elevator shaft slide, also easy to make a similar Hall effect or slot opto type of sensor set up.
    I assume you want it external to the elevator cage?
    Max.
     
  4. wayneh

    Expert

    Sep 9, 2010
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    The accelerometer, like the one is just about every smartphone, would be the preferred method. Lots of software and display options to go along with it. You can probably find one for free if it's a couple years old.

    Not long ago, a barometer would have been the leading choice, so maybe that's second now.

    An ultrasonic rangefinder in the top of the elevator shaft would probably work well for a few floors. Not sure what range is possible.
     
  5. MaxHeadRoom

    Expert

    Jul 18, 2013
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    Depends if the op just needs to detect motion or non-motion and/or rate.
    Also what it has to interface with.
    Max.
     
  6. ian field

    Distinguished Member

    Oct 27, 2012
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    Probably not much with all the clutter in an elevator shaft.

    An ultrasonic sensor facing up will fill with dust and crap. Pointing down will have an inconsistent target due to all the debris that accumulates in the elevator well.
     
  7. wayneh

    Expert

    Sep 9, 2010
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    I was thinking to put it at the top looking down at the car. But yeah, I'd just use a smartphone or a FitBit thingy.
     
  8. MaxHeadRoom

    Expert

    Jul 18, 2013
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    The OP says he want to detect motion in the lift when it starts, this could mean 'has it started' or 'what degree of motion is it' until known it is up in the air what what is needed, what would work?
    Max.
     
  9. EM Fields

    Member

    Jun 8, 2016
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    Do you need to measure anything, or just detect stops and starts on the way up and on the way down?
     
  10. profbuxton

    Member

    Feb 21, 2014
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    Whats wrong with an encoder on the cable drum shaft?. If the drum moves the lift moves(unless cable is broken, but thats another story)
     
  11. MaxHeadRoom

    Expert

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    If it is the old cable style, now many are hydraulic cylinder.
    Max.
     
  12. profbuxton

    Member

    Feb 21, 2014
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    Hydraulic, yes, but only for short lifts. Wouldn't work on 80 floor buildings. "Old cable style"???
     
  13. Amey@7823

    Thread Starter New Member

    Jun 25, 2016
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    Thanks DickCappels, for ur suggestions. I will go through it & see which matches best to my application....
     
  14. Amey@7823

    Thread Starter New Member

    Jun 25, 2016
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    Hey thanks Max. all I need it inside the elevator. & lifts are 90% are cable lift......
     
  15. Amey@7823

    Thread Starter New Member

    Jun 25, 2016
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    Ya you guessed it right. I need to sense the smallest motion in the lift. for example if lift moves , my circuit gives some text or voice messages to the passengers depending on the lift movement.
     
  16. Amey@7823

    Thread Starter New Member

    Jun 25, 2016
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    I am not measuring anything here. today's lifts are more reliable that when they starts, we couldn't feel any force or any motion.
     
  17. wayneh

    Expert

    Sep 9, 2010
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    Any smartphone would easily detect the motion.
     
  18. MaxHeadRoom

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    Jul 18, 2013
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  19. wayneh

    Expert

    Sep 9, 2010
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  20. DickCappels

    Moderator

    Aug 21, 2008
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    Yet the elevator arrives at some velocity after not moving, therefore it must experience acceleration in addition to the static acceleration of the of the earth's gravity.

    In theory this can be done with a sensitive enough accelerometer. Would you mind describing your accelerometer experiment? Somebody might be able to make a helpful suggestion.
     
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