Direct Phase Measurement and Compensation to Enhance MEMS Gyroscopes ZRO Stability

Pagani, Leonardo Gaffuri; Falorni, Luca; Fedeli, Patrick; Carulli, Paola; Langfelder, Giacomo

doi:10.1109/jmems.2021.3096031

Cited by 18 publications

(5 citation statements)

References 24 publications

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“…However, due to manufacturing tolerances, a portion of the drive motion will also couple to the sense mode, thus causing mass-flowindependent variations in C S . Since this mechanical crosstalk is 90 • phase-shifted relative to the Coriolis signal, it is commonly referred to as quadrature (Q) error and has been shown to be a significant source of drift in MEMS gyroscopes [28], [29], [30], [31], [32], [33], [34].…”

Section: Proposed Architecture and Circuit Designmentioning

confidence: 99%

“…This is because the Q error can be expressed as an input-referred mass flow offset ( Q ) that is directly coupled to the input mass flow ( I ). The measured mass flow rate ( O ) can then be expressed as follows [29]: (7) which shows that the drift in the measured mass flow rate O may be caused either by ϕ err and Q . Furthermore, ϕ err includes phase noise, which can further increase the noise floor in proportion to Q amplitude.…”

Section: Proposed Architecture and Circuit Designmentioning

confidence: 99%

“…The resulting k 0 ≈ ±ϕ err is then fixed and used for all subsequent measurements. It is important to note that any in-phase and quadrature parasitic couplings that appear at I and Q [29] may affect the accuracy of ϕ err estimation, thus leading to residual errors in the cancellation of Q in (7).…”

Section: Proposed Architecture and Circuit Designmentioning

confidence: 99%

See 2 more Smart Citations

A MEMS Coriolis-Based Mass-Flow-to-Digital Converter for Low Flow Rate Sensing

Oliveira

Pan

Wiegerink

et al. 2022

IEEE J. Solid-State Circuits

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This article presents a microelectromechanical system (MEMS) Coriolis-based mass-flow-to-digital converter (DC) that can be used with both liquids and gases. It consists of a micromachined Coriolis mass flow sensor and a CMOS interface circuit that drives it into oscillation and digitizes the resulting mass flow information. A phase-locked loop (PLL) drives the sensor at its resonance frequency ( f D ), while a low 1/ f noise switched-capacitor (SC) proportional-integral (PI) controller maintains a constant drive amplitude. Mass flow through the sensor causes Coriolis-force-induced displacements, which are detected by co-integrated sense capacitors. In-phase (I) and quadrature (Q) components of these displacements are then digitized by two continuous-time delta-sigma modulators (CT-Ms) with finite impulse response (FIR)-DACs and passive mixers. Their outputs are used to accurately estimate and cancel sense path delay, thus improving sensor stability. To ensure constant sensitivity over a wide range of fluid densities, a background sensitivity tuning (BST) scheme adjusts the sense capacitors' bias voltage as a function of f D , which is a good proxy for fluid density. Implemented in a standard 0.18-μm CMOS technology, the interface circuit consumes 13 mW from a 1.8-V supply. The proposed MEMS Coriolis DC achieves a state-of-the-art noise floor of 80 μg/h/ √ Hz and a zero stability (ZS) of ±0.31 mg/h, which is at par with MEMS thermal flow sensors.

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Section: Proposed Architecture and Circuit Designmentioning

confidence: 99%

Section: Proposed Architecture and Circuit Designmentioning

confidence: 99%

See 1 more Smart Citation

A MEMS Coriolis-Based Mass-Flow-to-Digital Converter for Low Flow Rate Sensing

Oliveira

Pan

Wiegerink

et al. 2022

IEEE J. Solid-State Circuits

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“…However, the asymmetry in damping leads to coupling between the drive mode and sense mode of the gyroscope, causing an in-phase error with the Coriolis signal sensed by the gyroscope. This error manifests as a threshold problem and a zero-input bias issue 13,14 . In the whole-angle mode, when the sensed rotation rate falls below a certain threshold, the gyroscope's mode shape becomes locked at a fixed angle, thereby compromising its ability to detect angular changes effectively 15,16 .…”

Section: Introductionmentioning

confidence: 99%

An automatic damping-matching method for eliminating 87.64% damping asymmetry of MEMS vibratory gyroscope in rate mode

Zhou,

Ren,

Zhou

et al. 2023

Preprint

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The damping asymmetry error is a prominent factor influencing the static performance of fully symmetrical Micro-Electro-Mechanical Systems (MEMS) vibratory gyroscopes. To eliminate this error and enhance the gyroscope's static performance, this paper introduces a method for real-time identification and automatic matching of the damping asymmetry error in rate mode. By leveraging the vibration characteristics of the fully symmetrical MEMS vibratory gyroscope in rate mode, dedicated online test methods are devised to determine the quality factors for both the drive and sense modes, enabling online identification of the damping asymmetry error. Furthermore, an automatic damping-matching system is devised utilizing the mechanical-thermal dissipation mechanism of a resistive damper. The effectiveness of this proposed method is validated through simulations and experiments conducted on a MEMS disk resonator gyroscope (DRG). The experimental results show an accuracy within 4% for quality factor identification, while automatic damping matching effectively reduces the damping asymmetry error by 87.64%. Employing this automatic damping-matching method successfully diminishes the zero-input bias caused by damping asymmetry error in the MEMS DRG from 0.1067°/s to 0.0249°/s and improves bias instability from 0.3985°/s to 0.1878°/s.

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“…In order to compensate for the phase error, direct phase measurement and online compensation between the large quadrature output and the demodulation reference was applied in the open-loop detection system to improve the zero-rate output (ZRO) stability [ 19 ], which requires the large quadrature output and the high phase resolution instruments. A real time circuit phase delay correction system was proposed in the double-loop FTR control system based on the amplitude-frequency characteristic of the drive mode [ 20 ], which adjusted the reference value of PLL by detecting the minimum excitation force amplitude.…”

Section: Introductionmentioning

confidence: 99%

Online Compensation of Phase Delay Error Based on P-F Characteristic for MEMS Vibratory Gyroscopes

Liu

Qin

2022

Micromachines

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In this paper, an online compensation method of phase delay error based on a Phase-Frequency (P-F) characteristic has been proposed for MEMS Coriolis Vibratory Gyroscopes (CVGs). At first, the influences of phase delay were investigated in the drive and sense mode. The frequency response was acquired in the digital control system by collecting the demodulation value of drive displacement, which verified the existence and influence of the phase delay. In addition, based on the P-F characteristic, that is, when the phase shift of the nonresonant drive force through the resonator is almost 0° or 180°, the phase delay of the gyroscope is measured online by injecting a nonresonant reference signal into the drive-mode dynamics. After that, the phase delay is self-corrected by adjusting the demodulation phase angle without affecting the normal operation of the gyroscopes. The approach was validated with an MEMS dual-mass vibratory gyroscope under double-loop force-to-rebalance (in-phase FTR and quadrature FTR) closed-loop detection mode and implemented with FPGA. The measurement results showed that this scheme can detect and compensate phase delay to effectively eliminate the effect of the quadrature error. This technique reduces the zero rate output (ZRO) from −0.71°/s to −0.21°/s and bias stability (BS) from 23.30°/h to 4.49°/h, respectively. The temperature sensitivity of bias output from −20 °C to 40 °C has reached 0.003 °/s/°C.

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Direct Phase Measurement and Compensation to Enhance MEMS Gyroscopes ZRO Stability

Cited by 18 publications

References 24 publications

A MEMS Coriolis-Based Mass-Flow-to-Digital Converter for Low Flow Rate Sensing

A MEMS Coriolis-Based Mass-Flow-to-Digital Converter for Low Flow Rate Sensing

An automatic damping-matching method for eliminating 87.64% damping asymmetry of MEMS vibratory gyroscope in rate mode

Online Compensation of Phase Delay Error Based on P-F Characteristic for MEMS Vibratory Gyroscopes

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