I am looking into making a "smart floor" that can detect when someone steps down onto it. I have done some research and found that the most commonly used sensors are 1) Pressure sensitive floor tiles 2) Electric Field sensors and 3) Vibration sensors.
The pressure sensitive tiles are pretty obvious but i'm not sure what sensors they are using. do they mean piezoelectric floor tiles? I haven't really been able to find help on how i would build one or if there are any commercially available to purchase where i can go to buy them
The Electric field sensors work by measuring changes in electric field when someone is present in the room. I am not sure exactly how but from what i read it seems like you are just stepping on a parallel plate capacitor and measuring the change in the capacitance to determine the amount of pressure.
Vibration sensors came up in my research and i assume they used microphones to detect the peoples steps.
The application: It will need to detect the presence of a person (and preferably location in the room, but not strictly necessary). It can (hopefully) detect more than one person and estimate how many people are in the room. It's main purpose will be at night where there will be less people walking through the room and people walking less frequently. The room is not huge but not tiny either, probably the size of a typical bedroom. The floor is hard, like marble.
I don't have a set budget but i do want to keep it somewhat reasonable, obviously.