Читать книгу Global Navigation Satellite Systems, Inertial Navigation, and Integration - Mohinder S. Grewal - Страница 87

These measure stress in the material connecting the proof mass to its enclosure. A spring scale measures the strain in a spring, which is proportional to the force (stress) applied. Similar designs use other means to measure that stress:

Beam accelerometers sense the surface tension on a supporting beam surface to measure the load normal to the beam surface due to applied specific force.

Piezoresistive accelerometers use the change in resistance in the stressed support material. MEMS accelerometers used for automotive air bag deployment have used piezoresistance.

Piezoelectric accelerometers have long been used for measuring vibrational acceleration, and have been used as essentially DC sensors in piezoelectric capacitors on MEMS beam accelerometers.

SAW (surface acoustic wave) accelerometers use strain‐induced shifts in the frequency of surface SAW resonators as a measure of the strain in the support material (a beam, for example).

Vibrating wire accelerometers use the frequency change in vibrating support wires due to changes in tension (stress) in the wires to measure the force applied by the wire to the supported proof mass. Because the fundamental vibration frequency of a wire under tension varies as the square root of tension, these are not linear sensors.

… and there are many more.