Electrostatic servo system for multi-axis accelerometers

A multi-axis capacitive accelerometer, using an electrostatic servo system was developed. In this system, an acceleration in three axes (X,Y,Z) is decomposed into its axial components independently and simultaneously by using the synchronous demodulation. The problem of off-axis response was solved by using the electrostatic force balancing to keep the seismic mass in the original position. Typical results achieved for off-axis sensitivity were 1.3-7.3%.