| 摘要 |
Disclosed is a method and apparatus for processing signals supplied by accelerometer assemblies in which one or more accelerometers are cyclically displaced in a predetermined manner so that signals representing the specific force experienced by the accelerometers and the angular rate experienced by the accelerometers are produced. The signal processor separately estimates the signal components of the signal being processed and provides an error signal by subtracting the estimated signal components from the signal being processed. The error signal is fed back through circuitry that controls the magnitude of the estimated signal components so that the value of each estimated signal component rapidly converges to the value of the signal components of the signal being processed. In an arrangement for determining the angular rate of one or more pair of cyclically displaced accelerometers, the signal processor includes a signal component that is in-phase with the signal that oscillates the accelerometer pair, a signal component that is in phase quadrature with the signal that displaces the accelerometer pair and a signal component that corresponds to random unmodulated additive noise. In this arrangement, a signal summing unit subtracts estimates of each signal component from the signal being processed to supply an error signal equal to (a1-â1) Cos omega t+(a2-â2) Sin omega t+(a3-â3), where a1, a2, and a3, respectively represent the values of the in-phase, quadrature and random noise components of the signal being processed and â1, â2, and â3 represent estimates of those signal component values. To obtain â3, the error signal is scaled and integrated. To obtain the â1 Cos omega t signal estimate, the error signal is multiplied by Cos omega t, and scaled to obtain a signal representative of the derivative with respect to time of â1. This signal is then integrated and multiplied by Cos omega t. The signal component â2 Sin omega t is obtained in a similar manner by multiplying the error signal by Sin omega t, scaling, integrating and multiplying the integrated signal by Sin omega t. In such an arrangement, angular rate is obtained by scaling the â1 signal estimate. In addition, the signal estimates can be used in an inertial navigation system that employs the invention to eliminate misalignment of the accelerometer pairs and to improve system operation by eliminating phase shift between the signal source that oscillates the accelerometer pairs and the signals provided by the accelerometer pairs.
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