Raspberry Pi Forums

Hi!

I'm working on a security system where an alarm goes off on detecting any intruder movement. I'm using a PIR sensor but that also detects animal movement along with human movement. Is there any sensor which detects only human presence and movement?

Thanks

Well, as Darwin pointed out, we're um, animals (some of us more than others).



What I did was setup a room just for my cats (in the cellar, very nice, cat run, climber, food water & sandbox) so that my sensors don't have to worry about cats vs humans; movement in my house is a problemo, and if my sensors go off I know its not the cat... phone goes off, and video starts rolling.

By the by, your cats will be happier too (if that's who you have) because they are territorial... they own your house anyways... and the more territory they have to patrol the more tense they become--- but I digress again.

malini wrote:Hi!

I'm working on a security system where an alarm goes off on detecting any intruder movement. I'm using a PIR sensor but that also detects animal movement along with human movement. Is there any sensor which detects only human presence and movement?

Thanks

Add sensitive audio recording. Walking with shoes has a different sound pattern than walking on four legs. So when the PIR triggers take a sound sample and look for a walking pattern, speech, engine sounds. I have once been working with a security system that tagged the alarms using this method.

With security you have to think of animal behaviour too.
The last thing you want is to deactivate the alarm because the cat is a traitor and follows the burglar around lol.
You can combine things, this is very time consuming, but more effective, with pets its always more difficult because you cant predict what they will do, and they can knock things over giving false noise and shock readings.
A heat sensor however is FAR more accurate, and ideal for a pi, pets are completely diff temp to humans, instead of PIR get in FLIR with vector tracing, now even a traitor pet wont give a false negative. The unintentional added bonus is immediate early fire alarm warning. (they are not cheap tho something like $200 for a dev kit) And the sun shining on a wall can give a false positive too, and last thing u want is to be told your house is on fire, just because the sun is streaming through the windows onto a work surface etc. but you can have bits masked and ignored.
Your alarm range is then a signature of 36.5-37.2'C
Cats are 37.7 - 39.1'C
Dogs are 38.39.2'C
So your device would tell the difference from human and pets, and when its outside those ranges it would take pics and upload them to FTP for you, and send a "unsure" via app to your mobile.

There are other ways, but thats one way i know that can difference between cat / dog / human. But as said be careful of traitor pet, scan the entire image, if it hits a large area of 36-37 u got a burglar.

StuckPI wrote:There are other ways, but thats one way i know that can difference between cat / dog / human. But as said be careful of traitor pet, scan the entire image, if it hits a large area of 36-37 u got a burglar.

Have you actually used this idea to tell if it is a dog, cat or human? What do humans look like to the sensor when they have a coat on? I remember reading someone complaining that they couldn't find ducks they'd shot using the FLIR but someone else pointed out the, you know, down they have on. Someone else told them that finding the ducks is what the dog is there for. I guess you use the FLIR to later find your dog.

This last idea though, which I was thinking about, is to use the size of the object to determine what it is. A cat sized object walking on the ground looks different than a human sized object, I would think. I'd still keep all the cat/dog/people images so I could keep an eye on all activity and which feral or neighbor's cat is eating my cats' cat food again.

One key characteristic of human beings is they walk on two legs; so perhaps a beam mounted at a height only humans could break might work, positioned across a hallway and away from any objects that a cat might decide to jump on. Could be laser, sonar, or even just PIRs shielded so they have a narrow field of view. Definitely not foolproof but very easy to do.

Combine it with wide-field PIRs to reduce false triggers.