Rate sensor drive and pick-off

摘要

An electromagnetic excitation device 10 is provided on a vibrating rate sensor (fig. 5, 18) thereby enabling larger air gaps (G) to be provided between the electromagnetic drive and electrostatic pick-off transducers (30, 60, 62). The larger air gaps are possible due to the larger magnitude of vibration produced by electromagnetic as opposed to electrostatic drive and help avoid the problems of viscous damping and dirt occlusion. The electromagnetic drive comprises a magnetic excitation device 12 for generating a magneto-motive force Fm and a vibrating structure 16 incorporating a paramagnetic region 14 which interacts with the excitation device 12 so as to excite vibration.