Seat belt buckle sensor

摘要

A seat belt buckle incorporates a spring mounted on the latch. When the latch engages with the tongue of a seat belt, the tongue can move against the spring in response to tension loading of the seat belt while remaining securely latched. This motion due to belt tension is resisted by the spring, with a selected spring constant. A sensor is used to monitor the presence and position of the tongue either directly or by measuring motion of the latch. The position information, which is related to spring compression, is used to determine loading on the tongue and thus seat belt tension.