Patent ID: 6324909
Filing Date: 2001-12-04
Classification: G01C

Abstract:
An acceleration sensing system, comprising:a dither assembly;a plurality of accelerometers mounted to the dither assembly for producing signals that indicate acceleration for three mutually perpendicular axes;apparatus for applying a dither drive signal to the dither assembly such that the accelerometers are dithered at a frequency .omega..sub.D and produce electrical accelerometer output signals that are modulated at the frequency .omega..sub.D ;apparatus for producing a first reference signal that is in phase with the dither drive signal and a second reference signal that is in quadrature with the dither drive signal;an accelerometer signal pickoff arranged to provide the accelerometer output signals;a multiplexer connected to the accelerometer signal pickoff;sensor signal processing apparatus connected to the multiplexer for sequentially processing sensor output signals for each of the three axes, the sensor signal processing apparatus including:a first rebalance path that includes:an in-phase demodulator arranged for demodulating the sensor output signal with the first reference signal;a first servo compensator connected for processing signals output from the in-phase demodulator to provide a rate signal; andan in-phase remodulator connected to the first servo compensator to remodulate the rate signal with the first reference signal;a second rebalance path that includes:a quadrature-phase demodulator arranged for demodulating the sensor output signal with the second reference signal;a second servo compensator connected for processing signals output from the in-phase demodulator to provide a signal indicative of the Coriolis acceleration of the sensor; anda quadrature-phase remodulator connected to the second servo compensator to remodulate the rate signal with the second reference signal;an acceleration channel that includes an acceleration channel servo compensator arranged to produce an acceleration feedback signal that is indicative of the linear acceleration input to the sensor along selected input axes; andan arithmetic logic unit connected to receive signals output from the first and second rebalance paths and the acceleration channel and produce an acceleration feedback signal; andapparatus for applying the acceleration feedback signal to the accelerometers to suppress motion of the accelerometers from Coriolis acceleration.