How to detect a person but not a bird or cat?

Thread Starter

AlbertHall

Joined Jun 4, 2014
11,309
I would like to detect when a person approaches the door.
I have a PIR by the door but it also gets spurious detections from birds (and possibly cats). How can I distinguish a person?
 

ericgibbs

Joined Jan 29, 2010
12,901
hi Albert,
I solved this bird problem for my outdoor PIR's by mounting two PIR units about 18 inches apart, horizontally then
ANDed the PIR outputs.

The object, usually a person has to activate both PIR's at the same time give an alarm alert, been working for a couple of years.

E
 
I would like to detect when a person approaches the door.
I have a PIR by the door but it also gets spurious detections from birds (and possibly cats). How can I distinguish a person?
Interrogate all triggers with a recorded message. Like maybe, "OK, WTF do you want". If its a human or a bird you may get a response, possibly even civil. Should work for everything except a cat, which as every cat owners knows, will simply ignore you :):)
 
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atferrari

Joined Jan 6, 2004
4,322
hi Albert,
I solved this bird problem for my outdoor PIR's by mounting two PIR units about 18 inches apart, horizontally then
ANDed the PIR outputs.

The object, usually a person has to activate both PIR's at the same time give an alarm alert, been working for a couple of years.

E
Why horizontally Eric? I expected them to be in the same vertical.
 

Thread Starter

AlbertHall

Joined Jun 4, 2014
11,309
Or you could use a camera and a neural network trained with millions of pictures of humans and non-humans approaching the door.

Bob
Yes, I have read quite a bit on this. It would need a dedicated computer and rPi seems to be inadequate. What I have found uses python and I am not familiar with python so there's a lot of learning to do down this road. It may come to that if all wlse fails.
 

Thread Starter

AlbertHall

Joined Jun 4, 2014
11,309
hi Albert,
I solved this bird problem for my outdoor PIR's by mounting two PIR units about 18 inches apart, horizontally then
ANDed the PIR outputs.

The object, usually a person has to activate both PIR's at the same time give an alarm alert, been working for a couple of years.

E
This is a promising idea. I could set detection times to detect slow moving people and reject fast moving birds. I will explore this - two PIR modules are on their way.
 

peterdeco

Joined Oct 8, 2019
357
Mount your sensor about 4 feet above the ground. Use electrical tape to shield the top and bottom portions of the sensor's lens to block detection above and below it. Now only a very large cat the size of a lion will trigger it.
 

ericgibbs

Joined Jan 29, 2010
12,901
hi Ramm,:)
It much simpler than that.
My two PIR's cover a garden path way.
I can detect the travel direction of the person, or large animal, up or down the pathway...
It is part a PIC based security system.
E
 

andrewmm

Joined Feb 25, 2011
1,466
I would like to detect when a person approaches the door.
I have a PIR by the door but it also gets spurious detections from birds (and possibly cats). How can I distinguish a person?
put notice up,
saying please ring bell,
I don't know any birds that can do that.
only turn on PIR when button pressed !!
 
Forgive me. I was attempting to inject a bit of levity into everyone's day. By the way, I do own an African Grey parrot that probably would respond although not in a civil manor. His rejoinders tend to be rather unrefined. Can't imagine where he learned that.
 

meowsoft

Joined Feb 27, 2021
367
hi Ramm,:)
It much simpler than that.
My two PIR's cover a garden path way.
I can detect the travel direction of the person, or large animal, up or down the pathway...
It is part a PIC based security system.
E
Can I get your PIC schematics ?, looks very good
 

tyro01

Joined May 20, 2021
18
When I made my own security sensor, I had a hard time distinguishing between people and animals. I used a non-directional model, which seemed to be a bad idea. In my case, I have two extremely directional EKMB PIR Sensor aligned in parallel. The power-saving design of this sensor allows it to operate for a long time on C Batteries.
 

nerdegutta

Joined Dec 15, 2009
2,681
You could use an RPi, a web cam and Motion. In the Motion conf-file you can set the amount of pixels to change before a script should run. Well, it doesn't have to be an RPi, just a computer running Linux.
 

drc_567

Joined Dec 29, 2008
1,110
... There is a low level entry radar module ... the XM132 (evaluation board XE132)... that produces a characteristic signal, as a solid object comes near it. The module appears to accept software modifications, and has a focusing lens accessory. Some additional design may be required in order to meet your requirements. ... The object/target presence signal would have to be converted to a useful digital form in order to activate a warning or alarm. It would seem that transient signals such as bird flight could be eliminated through the software.
 

Thread Starter

AlbertHall

Joined Jun 4, 2014
11,309
I got the PIR modules and a couple of waterproof boxes with clear tops to put them in.
BUT they don't work behind those clear tops. Oops!
So I will have to make a hole in the lid and poke the lens throgh it...
 

sparky 1

Joined Nov 3, 2018
541
to reduce false positives you can scan how large and what pattern the IR motion sensor makes.
An intrusion can be anywhere in a specified range but a moving reflected area and height should be measured at same distance.
The sensed area may from time to time give false positive with large dog because a small person would be the limit on how small.
 
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