Recent developments in flexured mass accelerometer technology

The flexured mass accelerometer (FMA) is being developed for high performance guidance applications. The focus of the present development is an accelerometer with the capability of meeting strategic missile thrust axis requirements but with a cost an order of magnitude lower than that for current thrust axis accelerometers and a mean time between failure (MTBF) in excess of fifteen years. The FMA uses a microwave readout to measure the deflection of a proof mass. Critical to the performance of this device is the bias stability of the flexured mass under loading. The flexure is mechanically open loop so there are stringent requirements on the flexure material and structural support. Candidate structural materials are reviewed. Specific requirements on the flexure support are identified. Modeling of the readout errors for the FMA indicate the specific requirements on the data sampling and the compensation algorithm. Error modeling and calculations include the effect of cross axis inputs as well as shock and vibration. Projections are made regarding the nuclear hardenability and circumvention requirements. Calibration requirements are reviewed