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Inherently robust micromachined gyroscopes with 2-DOF sense-mode oscillator
- Source :
- Journal of Microelectromechanical Systems. April, 2006, Vol. 15 Issue 2, p380, 8 p.
- Publication Year :
- 2006
-
Abstract
- Commercialization of reliable vibratory micromachined gyroscopes for high-volume applications has proven to be extremely challenging, primarily due to the high sensitivity of the dynamical system response to fabrication and environmental variations. This paper reports a novel micromachined gyroscope with two degrees-of-freedom (DOF) sense-mode oscillator that provides inherent robustness against structural parameter variations. The 2-DOF sense-mode oscillator provides a frequency response with two resonant peaks and a flat region between the peaks, instead of a single resonance peak as in conventional gyroscopes. The device is nominally operated in the flat region of the sense-mode response curve, where the amplitude and phase of the response are insensitive to parameter fluctuations. Furthermore, the sensitivity is improved by utilizing dynamical amplification of oscillations in the 2-DOF sense-mode oscillator. Thus, improved robustness to variations in temperature, damping, and structural parameters is achieved, solely by the mechanical system design. Prototype gyroscopes were fabricated using a bulk-micromachining process, and the performance and robustness of the devices have been experimentally evaluated. With a 25 V dc bias and 3 V ac drive signal resulting in 5.8 [micro]m drive-mode amplitude, the gyroscope exhibited a measured noise-floor of 0.64[degrees]/s[square root of Hz] over 50 Hz bandwidth in atmospheric pressure. The sense-mode response in the flat operating region was also experimentally demonstrated to be inherently insensitive to pressure, temperature, and dc bias variations. [1501] Index Terms--Inertial sensor, MEMS gyroscope, micromachined gyroscope, rate sensor.
Details
- Language :
- English
- ISSN :
- 10577157
- Volume :
- 15
- Issue :
- 2
- Database :
- Gale General OneFile
- Journal :
- Journal of Microelectromechanical Systems
- Publication Type :
- Academic Journal
- Accession number :
- edsgcl.144931993