Method for measuring rotation speed and rotation speed sensor provided with a fibre-optical Sagnac interferometer

摘要

The fundamental idea of the invention is to use the Sagnac effect both to measure rotational speed and to reset a fibre optic gyroscope. At least one segment (10) of the fibre coil (8) of a Sagnac interferometer is wound separately onto a solid of revolution, which is driven by a motor (14) and is preferably arranged coaxially and centrally with respect to the measuring coil. The interferometer output signal feeds an electronic control circuit (13) which adjusts the speed of the motor (14) in such a way that the interferometer output signal vanishes due to corresponding rotation of the part of the fibre coil wound onto the solid of revolution. The rotational speed of the solid of resolution relative to the sensor housing is evaluated as a measure of the inertial rotational speed. The result of the optomechanical rotational speed transformer according to the invention, the transformation ratio of which is freely selectable in principle, is that the temperature dependence of the scale factors vanishes, on the one hand, and that the rotational speed to be converted via the transformation ratio can be measured relatively simply via an optical decoding disc (15), on the other hand. IMAGE