| 摘要 |
A dual sensor, frequency output accelerometer that does not require either high sampling rates or mechanical matching of the sensors to achieve high levels of accuracy. In one embodiment, the accelerometer comprises a first sensor (12, 14, 16) that produces an output signal S1 having a frequency f1 related to acceleration along the sensitive axis, and a second sensor (18, 20, 22) that produces a second signal S2 having a frequency f2 related to acceleration along the sensitive axis, the sensors being arranged such that a given acceleration causes the frequency of one output signal to increase and the frequency of the other output signal to decrease. Velocity change DELTA V during time interval T is determined according to: DELTA V = A[ DELTA PHI + FT + B SIGMA PHI ] where A, F and B are constants, DELTA PHI is the difference between the phase changes of the output signals over time interval T, and SIGMA PHI is the sum of the phase changes of the output signals over time interval T. Higher order correction terms are also described for very high precision applications. Also disclosed is an accelerometer for measuring velocity change during a time interval that includes a subinterval during which electrical power is unavailable. |
