MICROMECHANICAL TUNING FORK GYROSCOPE TEST RESULTS

摘要

For automotive applications, Draper Laboratory and Rockwell are developing small, low cost single crystal tuning fork gyroscopes using microfabrication technology. These tuning fork gyro's are extremely rugged, inherently balanced, and easy to fabricate. The gyroscopes are fabricated from single crystal silicon anodically bonded to a glass substrate (dissolved wafer process). For a 1 mm silicon gyroscope, projected performance is 10 to 100 °/hr for bias stability and for resolution in a 60 Hz bandwidth. Resolution of 560 °/hr in a 60 Hz bandwidth (0.8 °/(Hr)~(1/2) angle random walk) and bias stability of 120 °/hr overnight have been demonstrated with self drive oscillation. In special tests, resolution better than 150 °/hr has been recorded. Without compensation, the bias changes 3600 °/hr as instrument and electronics temperatures vary from -40 to +85℃. This data was taken with the Engineering Development Model 2 (EDM2) electronics. In this paper the following topics are covered: the principle of operation, fabrication of silicon gyroscopes, and projected and measured performance. Associated electronics and control issues will also be addressed.