how do automatic doors work?

Question

so im an architecture student first year. im trying to design a rather weird automatic door for my façade but dont know the first thing about automatic doors.
basically instead of two big sheets of glass that move aside so you can walk in there will be multiple horizontal bars which are on top of each other and move have motion sensors at the tip on both side and when you stand in front of the door each of them scan you and open only enough so you can pass through (just to make it a bit different). but i dont know how to make it work or how to design it.
please help

Answer 1

You need a linear actuator for each bar, and an infra red laser on the tip of each bar. The bar retracts until the reflected beam (from the person) is no longer visible, then stops. You could also use an ordinary red laser pen if you don't mind the beams being visible. You might also want a PIR detector over the door to turn the entire mechanism off if there is nobody nearby.



Linear actuators are a little expensive, you might want to design your own based on winding a string onto a motor driven drum.

Answer 2

>Linear actuators are a little expensive, you might want to design your own based on winding a string onto a motor driven drum.



If I read Dave correctly then you could use the winding drum, but that's only going to open the door, not close it. For a conceptual project you could just do this with Dave's plan or something like it and call it a day. If it were to be actually built then you have another issue - insulation. You can't have a door with rods with 1/2" spaces between, you can't realistically (economically) machine those rods to a tolerance that is THAT tight and also expect it to have a useful lifespan, and if you somehow insulate between them then everything is different and you add considerable friction to your motion.



The rods also need to be thick enough to support their own weight to a tight tolerance over several feet, and be mounted into the wall the same way.....

Answer 3

Automatic sliding doors use optical or motion detection sensors to activate their motorized opening and closing functions. These sensors are mounted over the automatic door or are integrated into the door framing from above or the side. The sensors use either infrared or microwave technology to observe motion