Construction of three-axis acceleration sensor using a cross-coupled vibrator

We describe an acceleration sensor composed of four vibration bars, with a detection mechanism in which the resonant frequencies of the four bars are brought close together. The bars are connected mechanically at the center, and a cross-shaped layout is used such that for any load direction, the sizes of the loads on the vibration bars mutually oppose each other. Using this structure, acceleration can be easily calculated by the differential detection of the oscillation amplitude signals of each of the four vibration bars. The acceleration sensor in these three axes realized high stability and highly sensitive detection by driving four coupled vibrators. The sensor characteristics are measured using the gravitational field, and the acceleration is changed by rotating the sensor around the axis along the length of the vibrator.