Rotation-measurement apparatus having a vibrating mechanical resonator

摘要

A mechanical resonator 10 provided with transducers 15 1 and 15 2 enables an axially-symmetrical standing wave to be set up in the resonator. The apparatus also comprises sensors 16 for measuring the elongation of the resonator vibration in at least two particular directions and a monitoring and control circuit 12 for sustaining the vibrations and for detemining the locations of the vibration nodes and anti-nodes. The monitoring and control circuit powers the transducers to generate two contra-rotating travelling waves in the resonator with the phase difference between them being representative of the angle of rotation of the resonator about its axis of revolution. The amplitudes of the waves are such that when combined they give rise to a standing wave of determined in-phase amplitude and of quadrature amplitude that is substantially zero. The apparatus can be applied to any form of resonator e.g. a disk or a bowl.