How to locate my cats in my house?
First, if you want to keep cats out of a room, you have to physically bar them from the room.  "Explaining" the forbiddeness to a cat doesn't work, LOL.  Keep the door closed or whatever, and then you don't need to know where the cats are anymore.

If you really want to track cats, a network of passive IR sensors around the house is probably the best way that meets your specs.  You may want some at different levels to distinguish between a human and a cat, in places the cat can't cross by walking higher along furniture and the like.  The tricky part here is the software to make sense of all the individual "I see something warm moving here" signals to actual tracking of the warm things.