How to detect a dog on a bed?

Question

Electronics

There is a smart-assed dog (Chihuahua) that is forbidden to jump on the child's bed.
The dog quickly realized that "not caught - not a thief" and learned quickly at the first sign of a check to dump out of bed and, perhaps, not to whistle, they say, I don’t know what kind of bed this is.

Actually the task: a smart home must somehow detect the fact that the dog is on the bed.
Additional terms:

1. minimize false positives.
   
2. it is not advisable to install video surveillance, after all, the child's room.
   
3. in view of the small caliber of the dog, she does not want to hang a collar that is too heavy.
   

Options considered:

• RFID (dog localization problem, does not work clearly, the angle between the antennas is critical);
  
• active acoustic location: a piezo element with a controller on the collar, a Chinese ultrasonic transceiver module on the ceiling above the bed. The collar, having heard the signal, instantly gives an answer. The distance to the dog is characterized by a short time;
  
• camera with opencv on board, with recording disabled. The option is bad, no one likes to live under the gun even if the camera is turned off.
  

What other options?

Answer 1

The weight!
1. dogs
2. beds
3. child
Under the legs strain gauge.
1+2 - alarm
1+2+3 - alarm

Answer 2

Point any webcam at the sofa and set up motion detection in the selected area (there are a lot of applications). If you make the movement, then you will know that it is you, if not you, then it means a dog.

Answer 3

Use a machine vision platform based on kendryte k210, recognition is offline. You can train your own network, or you can use a ready-made model where there is a dog. Maixduino https://mysku.ru/blog/aliexpress/79416.html
Cost from $15 (sipeed M1n)

Answer 4

I would approach from the right side - the formation of the habit "sitting on the bed - it hurts."
a blanket with conductors to which very short pulses of increased voltage are applied.
as they say "even a fool understands everything from the first blow" ...

Answer 5

Matrix thermal imager AMG8833 - detect the appearance of a thermal spot. There is an 8x8 matrix - privacy will not hurt ...

- a camera with opencv on board, with recording disabled. The option is bad, no one likes to live under the gun even if the camera is turned off.

Defocus focus - detect a color spot. It is possible on Raspberry Zero with no wifi on board - only signal output to GPIO. If the very fact of having a camera confuses me, I can recommend a foil cap)

Answer 6

Active acoustic location, IMHO, not very good. dogs hear in ultrasound - you need to check the frequency range.
I like the idea with a thermal imager.

Answer 7

An industrial thermal imager will show a heat spot from the carcass after a few minutes.
The pyrometer will show the presence of a carcass on the bed (including the child).

Answer 8

Get a cat. He will sleep on the bed, and he will tear such a dog to shreds if he climbs to him :)
But it was necessary from the very beginning so that they would grow up together and be accustomed to where anyone can sleep.
But seriously, you need to simplify the task a little - let the dog be forbidden to enter the room where the bed (which is forbidden to climb on). Then we put two optical sensors in the doorway, one at the level of the dog, the second is guaranteed higher, but so that the daughter definitely does not pass under it, even on her haunches. Then the logic is simple - two sensors worked - a person passed, only the lower one worked - a dog (we shock from the collar, well, or whatever they planned to punish, you can turn on the siren and call the riot police :-)

spoiler

Вот тут рассуждают - контроллеры, умные камеры, нейронные сети, детекторы движения, тепловизоры... Будто президента охраняют. С двумя простыми датчиками и никаких контроллеров не надо.