Compact, Flat-Quartz, Vibratory, Angular-Rate Sensor Module Using T-Shaped Resonators

A compact, angular-rate sensor module has been developed using a flatly supported, quartz sensing element of double T-shaped resonators. The sensing element has both drive and pickup resonators in the same plane of a Z-cut quartz wafer to detect angular-rate motion perpendicular to the plane so that the sensor module can fit in space 5.6mm high along with its sensing axis. Thanks to good stability of the quartz, and symmetric structure of the double T-shaped resonators, the sensor module also can achieve small offset drift, high S/N (Signal to Noise ratio), and excellent immunity to vibration noise.

In this paper, the principle of the sensing element is briefly explained followed by detailed discussions on the angular-rate sensor module's: 1) Structure 2) Performance and 3) Field Testing. The module structure is described to show how to assemble the three parts; targeted and actual performance including Allan variance are discussed based on laboratory evaluation results; and the first field test data of combination with a GPS (Global Positioning System) receiver are examined.