Distributed-mass micromachined gyroscopes for enhanced mode-decoupling

A novel micromachined z-axis gyroscope with multidirectional drive-mode is presented. The design concept aims to relax mode-matching requirement, eliminate effects of directional residual stresses, and completely decouple the drive and sense modes. The proposed approach is based on denning multiple drive-mode oscillators, distributed symmetrically around the center of a supporting frame. Quadrature error and zero-rate-output are minimized, since the instability and drift is suppressed, due to the enhanced decoupling of multidirectional linear drive-mode and the torsional sense-mode. By designing each drive-mode oscillator with incrementally spaced resonance frequencies, a constant total Coriolis torque is achieved over a wide range of driving frequencies, leading to relaxed mode-matching requirements; and thus, robustness and reduced sensitivity to structural and thermal parameter fluctuations are achieved. Bulk-micromachined prototypes have been fabricated in a one-mask SOI-based process, and experimentally characterized.

[1]  Y. Mochida,et al.  A micromachined vibrating rate gyroscope with independent beams for the drive and detection modes , 2000 .

[2]  Yong-Kweon Kim,et al.  A few deg/hr resolvable low noise lateral microgyroscope , 2002, Technical Digest. MEMS 2002 IEEE International Conference. Fifteenth IEEE International Conference on Micro Electro Mechanical Systems (Cat. No.02CH37266).

[3]  Andrei M. Shkel,et al.  FOUR DEGREES-OF-FREEDOM MICROMACHINED GYROSCOPES , 2001 .

[4]  Weichen Xue,et al.  Design and characteristics of two-gimbals micro-gyroscopes fabricated with quasi-LIGA process , 1997, Proceedings of International Solid State Sensors and Actuators Conference (Transducers '97).

[5]  J. Frech,et al.  Decoupled microgyros and the design principle DAVED , 2001, Technical Digest. MEMS 2001. 14th IEEE International Conference on Micro Electro Mechanical Systems (Cat. No.01CH37090).

[6]  Robert P. Leland.  Adaptive tuning for vibrational gyroscopes , 2001, Proceedings of the 40th IEEE Conference on Decision and Control (Cat. No.01CH37228).

[7]  Said Emre Alper,et al.  A symmetric surface micromachined gyroscope with decoupled oscillation modes , 2002 .

[8]  R. Horowitz,et al.  Adaptive control for z-axis MEMS gyroscopes , 2001, Proceedings of the 2001 American Control Conference. (Cat. No.01CH37148).

[9]  Y. Mochida,et al.  A micromachined vibrating rate gyroscope with independent beams for the drive and detection modes , 2000, Technical Digest. IEEE International MEMS 99 Conference. Twelfth IEEE International Conference on Micro Electro Mechanical Systems (Cat. No.99CH36291).

[10]  Roberto Horowitz,et al.  Dynamics and control of micromachined gyroscopes , 1999, Proceedings of the 1999 American Control Conference (Cat. No. 99CH36251).

[11]  Farrokh Ayazi,et al.  Micromachined inertial sensors , 1998, Proc. IEEE.

[12]  A. Shkel.  Modeling and simulation of micromachined gyroscopes in the presence of imperfections , 1999 .

[13]  Jong-Hyun Lee,et al.  A laterally driven symmetric micro-resonator for gyroscopic applications , 2000 .