Fiber optic measuring device for determining restraint forces of e.g. pelvic belt, in motor vehicle, has strap at which measuring point is fitted by textile, where change of characteristics of fiber at point causes change of fiber behavior

摘要

The device has transmitting devices (7a, 8a) supplying light into an optical fiber of two fiber-optic sensors (2), and receiving devices (7b, 8b) receiving the light from the fiber and producing electrical signals representing the received light. A load determining device determines load valves that represent a mechanical load of the fiber at a measuring point, based on the electrical signals. The measuring point is fitted in a belt strap (1) by a textile, where a change of local optical characteristics of the fiber at the measuring point causes a change of reflective behavior of the fiber. Independent claims are also included for the following: (1) a restraint belt system with a measuring device (2) a method for regulating restrain force of a restraint belt.