I want to do a system or robot that detects someone is using a desk. My question is which sensor or type of detection you would recommend me to use to allow to know someone is using a desk.
My choice are:
-Using an LED and LDR under the table if a person sits, it will detect. (If they wear a black cloth maybe it will not reflect back).
-Use an RFID tag, the person that uses the desk's touch with a tag.
-Distance sensor, in ebay this sensor is very cheap.
Not Automatic choice
-Push button, the person that uses the desk to just press a button.
First i thought you want to detact if somebody is using the desk who is not supposed to do so.
After reading your post again i got the picture
The most simple solution would be a push button.
However, what you want to achieve? Do you want only authorized people using the desk? In this case you will need a kind of password or other authentification method like finger print, face detection. But that may be to complicate.
Again, we would need a bit more details about what you want to achieve.
It’s pricey at $120 but if you don’t mind the price, this thermal array sensor would do the job. I use it on my bot to track people/cats/coffee. It works quite nicely.
You would be able to tell the different between a person sitting vs. someone throwing a backpack in a chair and getting a false alarm from a pressure sensor. Also, if they bending over desk without sitting, you’ld still get them with the thermal array. You could easily filter out hot coffee/pets by looking at the size of the heatsource in pixels.
I wonder if one could figure out placement of a PIR sensor that would work. I am currently thinking more or less straight up, then add a timer. If the PIR is triggered for a given amount of time, the desk is being used.
