Detecting people with triangulation technology – an alternative to cameras or thermal imaging

June 14, 2013 // By Graham Prophet
Detecting people and animals presents similar technical application requirements. People wear clothes in various colours or with varying structures, animals may have long or short fur or feathers; they can also be dirty or wet. Triangulation technology offers a solution that helps to detect objects independent of the colour, the material, and the surface structure.

The sensor's emitter and receiver are incorporated together in one housing. The emitting element sends light that is reflected diffusely on a surface and the reflected light is captured by a receiving element in the sensor. Depending on the distance between the sensor and the object, the angle of the captured light changes, which in turn helps the sensor determine the distance. The sensor switches ON/OFF according to the distance measured and not according to the light quantity, as this may vary depending on the colour, appearance, or structure of the object to be detected.

Triangulation technology has been implemented by Panasonic in three different product series. Depending on the actual application, each series offers advantages regarding sensing range and sensor size. EQ-500 is a multi-purpose sensor with a sensing range of up to 2.5 meters. Where the application requires a compact sensor, the series EQ-30 with the dimension of 68 x 40 x 20 mm is the best solution. The CX-400 series is very good at background suppression.