Fibre-Optic Sagnac Interferometer with Digital Phase Modulation for Measuring a Rate of Rotation

摘要

The subject of the invention is a fibre-optic rate of rotation sensor in open loop configuration, in which sensor bias errors which arise on account of coupling in of disturbing signals into the input of a demodulator (SYNCD) are suppressed by the use of a demodulation signal which is statistically independent of all signal sources which may be considered as a cause of ~ disturbing signals. To this end, a modulation signal generator (MG) is provided, which includes a random number generator from which two signals (b0, b1) are derived on the one hand for a statiscally alternating bias for the activation of optimal working points with positive or negative gradient on the interferometer characteristic and an appropriately matched demodulation signal (d) is derived on the other hand, which demodulation signal, after transit time correction (T0), acts upon the synchronous input of the synchronous demodulator (SYNCD).