摘要 |
<p>A single axis rate sensor (10) comprising a cylinder (12) positioned about an axis (x) and having primary and secondary drive and pick-off transducers (14,16) and primary and secondary control loops (22,23). Said primary control loop (22) being provided for maintaining resonance of the cylinder (12) by generating a ninety degree phase shift between the primary drive transducer (14) and the primary pick-off transducer (18). Said secondary control loop (23) being provided for receiving a signal from the secondary pick-off transducer (20) indicative of rotation of the cylinder (12) and for nulling the secondary drive transducer (16) to zero. The primary control loop (22) includes a phased locked loop having a phase detector (30) configured to operate at quadrature. By operating the demodulator in quadrature the demodulator (30) and loop filter (32) combination will be a linear device which will not mix the microphonic baseband signal with the carrier, there will therefore be a reduction and possible an elimination of the modulation of the voltage controlled oscillator (34) by microphonic noise. <IMAGE></p> |