​The automatic doors at grocery stores and office buildings mainly exist for convenience. The automatic doors in an elevator, on the other hand, are absolutely essential-theykeep people from falling down an open shaft. Elevators use two different sets of doors: doors on the cars and doors opening into the elevators shaft. The doors on the cars are operated by an electric motor, which in turn is operated by the elevator computer.

How they work:

• Automatic doors utilize sensors to detect the presence of people or objects. 

• These sensors can include infrared sensors, pressure-sensing pads, or motion detectors. 

• When a person or object is detected, the door controller activates the motor to open the door. 

• After a set period, the door closes automatically unless another activation signal is received. 

• Safety sensors are installed to prevent the door from closing if there is an obstacle.