Triangulation sensor
From Wikipedia, the free encyclopedia
Optical Triangulation Sensors are commonly used to provide door mounted safety detection on swinging automatic doors. These types of sensors are common in North America. When automatic swinging doors open and close, it is important that they do not come into contact with pedestrians passing through the door.
Sensors used in the automatic door industry typically fall into four categories:
- Microwave sensors used to detect motion of a person as they approach an automatic door,
- Reflective optical sensors that are mounted on the door header, and detect the presence of a person in the door path
- Camera based sensors that are also mounted on the door header and similarly detect presence; and
- Triangulation sensors which are mounted on the door and move with the door to provide safety.
Reflective and camera technologies do not perform well on moving swing doors, because they typically depend upon detection of changes in the background. A sensor mounted on a swing door system is constantly in motion, so the background (i.e. floor beneath the door) changes continuously. A triangulation sensor overcomes this problem.[citation needed]