High Scale-Factor Stability Frequency-Modulated MEMS Gyroscope: 3-Axis Sensor and Integrated Electronics Design

Abstract

This paper reports the developments towards an integrated, triaxial, frequency-modulated, consumergrade, MEMS gyroscope. A custom low-power (160 µA), low-phase-noise integrated circuit is designed specifically for frequency-modulated operation. Both yaw-and pitchrate sensing systems are demonstrated, by coupling the circuit with two novel micromachined structures fabricated with a 24-µm-thick industrial process. In operation, both gyroscopes show a repeatable and stable scale factor, with less than 0.55% of part-to-part variability, obtained without any calibration, and 35 ppm/ • C of variability over a 25 • to 70 • C temperature range.

Automated Frequency and Quality-Factor Matching Method for Frequency Modulated / Rate Integrating Gyroscope

“…[4][5][6][7] FM gyroscopes measure angular rate using the phenomenon of the frequency of the rotational motion mode of the resonator being modulated by the angular rate. [4][5][6][7] FM gyroscopes measure angular rate using the phenomenon of the frequency of the rotational motion mode of the resonator being modulated by the angular rate.…”

“…Therefore, this method can, in principle, be used to obtain measurements that are not influenced by temperature. 6,7,9 Since the Lissajous locus is equivalent to the continuous switching between the CW mode and the CCW mode, the resonant frequency is modulated by the angular rate. 5 However, with this method, it is not possible to maintain oscillation and, consequently, practical gyroscopes cannot be realized.…”

“…As such, in recent years, there have been many efforts to develop a frequency modulation (FM) gyroscope that is free of temperature sensitivity. [4][5][6][7] FM gyroscopes measure angular rate using the phenomenon of the frequency of the rotational motion mode of the resonator being modulated by the angular rate. The resonant frequency is modulated in opposite directions in the clockwise (CW) mode and the counter clockwise (CCW) mode as expressed by the following:…”

“…A similar method is to use the two-dimensional Lissajous oscillation of a single resonator for which the resonant frequency of the X-and Yaxes is intentionally shifted. 6,7,9 Since the Lissajous locus is equivalent to the continuous switching between the CW mode and the CCW mode, the resonant frequency is modulated by the angular rate. As a result, the angular rate can be measured by demodulating the modulated component.…”

Automated frequency and quality‐factor matching method for frequency modulated / rate integrating gyroscope

“…As such, in recent years, there have been many efforts to develop a frequency modulation (FM) gyroscope that is free of temperature sensitivity . FM gyroscopes measure angular rate using the phenomenon of the frequency of the rotational motion mode of the resonator being modulated by the angular rate.…”