occupancy sensor
Building automation concepts take motion detectors and presence sensors into account for alarm triggering and automation. Last but not least, they make a significant contribution to energy savings.
The presence sensor or presence detector determines whether someone is in a room or in the vicinity of an object. Such a sensor must be able to detect moving and non-moving persons. Accordingly, the technical concepts are also based on infrared and ultrasound.
While infrared sensors use infrared radiation to determine whether a person is in a room, ultrasonic sensors use a comparison method. They compare the current with the characteristic room echo. In addition to the classic measured variable, which tells whether someone is in the room, this approach calculates an integral variable for movement activity.
In infrared systems, there are developments that work with sensor arrays and can determine whether a person is sitting, standing or lying down. With this technology, disturbing influences from radiators are eliminated, as is the day-night influence. Corresponding systems work with image data acquisition and use the data obtained to control lighting and heating.