| 摘要 |
A force rebalance accelerometer includes a proof mass suspended by one or more flexures between stationary mounted upper and lower excitation rings. Pick-off capacitance plates formed on opposing sides of the proof mass are used to form upper and lower capacitance elements whose capacitance varies in response to displacement of the proof mass to provide a displacement signal. The displacement signal is applied to one or more electromagnets which are used to force the proof mass back to a null or at-rest position. The drive current applied to the electromagnets thus represents the force or acceleration applied to the accelerometer. The electromagnets include a magnet, rigidly secured to an excitation ring which forms a magnetic return path. A flux control groove is formed in the excitation ring to reduce leakage flux and flux concentration which would otherwise result in the magnetic return path at the magnet interface. By relieving the stress and leakage flux at the magnet interface, the accelerometer in accordance with the present invention will provide relatively stable output signals and not be particularly sensitive to temperature or environmental variations while providing relatively stable thermal hysteresis and drift performance.
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