Advice needed: Detecting humans

Comments

• Paul Baker Posts: 6,351

  2006-02-13 17:52 edited 2006-02-13 17:52

  I would combine the PING))) sensor and PIR sensor together, PIR to determine if its a human, and the PING))) to get the distance. This wont work for all circumstances when there are other large non-human objects in the PING's field of view. But if you do your best to make the two sensors pointing in the same direction and attempting to make the field of view of both sensors the same, you should be able to minimize this type of error.
  
  ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
  ·1+1=10
• John R. Posts: 1,376

  2006-02-13 18:59 edited 2006-02-13 18:59

  PIR and PING might also have tough time differentiating Spot or Morris from a human, especially if you need to sense the small humanoids that like to put stuff (like little boe-bots) in their mouths. (I'm assuming the "get too close" action would be something like "Don't Touch Me!")
  
  This (sensing pets) may or may not be a factor.
  
  ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
  John R.
  
  8 + 8 = 10
• cocokiwi Posts: 75

  2006-02-13 21:48 edited 2006-02-13 21:48

  suza_phone said...
  I'm working on an artistic project ...
  and one of the things that I want to do is:
  To have a robot do "this" when a person is detected in some distance and do "something else" when that person gets too close.
  
  Obviously a PIR-sensor can only give information on whether there is a person (movement) or not - but it doesn't give any information on the distance between person and robot, right?
  Does anyone have advice on sensors or maybe even a combination of sensors to use for solving that problem? Distance would be ultrasound and iR ... as far as I understand.
  
  Would it make sense to somehow combine the information coming from those sensors - and how would I best do that in my program?
  Something like, only active ultrasound when human has been detected by PIR???
  
  Another issue is that my project combines a number of robots and so most preferably the bots should be able to differentiate between a human "obstacle" and another bot (or the wall) etc.
  
  Thanks in advance for all suggestions
  
  I would use a combined set,a pir to sense something at range and the camera to sense movment,get both ALARM
  
  Try This item: http://www.saelig.com/miva/merchant.mvc?Screen=CTGY&Category_Code=VI
  
  ·at $35.00·· VMD-19 the small item is a Video Motion Detector which goes in serries with a Video camera..it has two outputs :
  
  one is a video off indicator the other is the alarm out:·· There is a two wire setting...for sensitivity and·one for Inside/outside·via a switch!
  
  This is a gem! and cheap!· One could use a stamp to control it(autosense the sensitivity would be interesting) Turning off the Video camera to save power and having a means to know it(grin)
  
  Cheers Dennis
• LoopyByteloose Posts: 12,537

  2006-02-14 10:00 edited 2006-02-14 10:00

  PIRs can be used with optics. Use more than one that is set up to trigger at particular ranges.
  
  Your biggest problem is having a crowd as everything triggers.
  
  I think that most people hope that a sensor will do 'everything' they need. In this case, it might take a camera and some pretty sophisticated processing of digital imagine to get it all. The PIRs are dependent on the thermal image of warm-blooded people and cannot see BOTs [noparse][[/noparse]unless they are producing ample heat].
  
  IR sensors are noted for not seeing black. Ultrasonic sensors have difficulty with reflected sound in a room. As you begin to see, the miracle of being humanly aware of our surroundings really remains a challange -- especially when a limited budget is in the mix. Just plain old audio input is useful too.
  
  ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
  "When all think alike, no one is thinking very much.' - Walter Lippmann (1889-1974)
  
  ······································································ Warm regards,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan