scholarly journals A Decoupling Design with T-Shape Structure for the Aluminum Nitride Gyroscope

Micromachines ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 244
Author(s):  
Yang ◽  
Si ◽  
Han ◽  
Zhang ◽  
Ning ◽  
...  
Keyword(s):  
Aluminum Nitride ◽  
Microelectromechanical Systems ◽  
Sense Mode ◽  
Drive Mode ◽  
Aln Film ◽  
Shape Structure ◽  
Mems Gyroscopes ◽  
Sense Electrode ◽  
Working Principle ◽  
Novel Design

This paper reports a novel design for the decoupling of microelectromechanical systems (MEMS) gyroscopes. The MEMS gyroscope is based on piezoelectric aluminum nitride (AlN) film, and the main structure is a mass hung by T-shape beams. A pair of parallel drive electrodes are symmetrically placed on the surface of the vertical bar for driving the oscillating mass. A serpentine sense electrode is placed on the lateral bar. When the gyroscope is oscillating in drive mode, charges with equal quantity and opposite sign will be polarized and distributed symmetrically along the lateral bar. These charges neutralize each other at the sense electrode. Therefore, no coupling signals can be detected from the sense electrode. This design can realize the decoupling between the drive mode and sense mode. In this work, the T-shape decoupled structure was designed as the key component of an AlN piezoelectric gyroscope and the whole structure was simulated by COMSOL Multiphysics 5.2a. The working principle of the decoupling is described in detail. Electrical properties were characterized by the dynamic signal analyzer. According to the test results, the drive mode and the sense mode are decoupled. The coefficient of orthogonal coupling is 1.55%.

Design Optimization for Non-Resonant MEMS Gyroscope

2009 ◽  
Author(s):  
Wei Cui ◽  
Xiaolin Chen ◽  
Wei Xue
Keyword(s):  
Device Performance ◽  
Sense Mode ◽  
Drive Mode ◽  
Resonant Frequencies ◽  
Frequency Matching ◽  
Wide Range ◽  
Mems Gyroscopes ◽  
Capacitive Mems ◽  
Effective Design ◽  
Model Approach

Conventional capacitive MEMS gyroscopes require close matching between the resonant frequencies of drive mode and sense mode. However, the uncertainties in the microfabrication process impair the robustness of the gyroscopes and often lead to unpredictable device performance. This paper analyzes a 4 degree-of-freedom (DOF) non-resonant gyroscope which is less vulnerable to the fabrication perturbations. Unlike the conventional resonant gyroscope which has only one resonant frequency for drive and sense modes, the 4-DOF gyroscope includes two resonant frequencies for each mode. The non-resonant gyroscope design aims to reduce resonance frequency matching, namely to minimize the effect of the inevitable fabrication uncertainties as well as to increase the bandwidth with less sacrifice to the sensitivity. The device performance is analyzed and optimized by the behavior model approach in CoventorWare which significantly accelerates the simulation compared to the traditional finite element method. The optimized non-resonant gyroscope with higher fabrication tolerance as well as enhanced device performance is proven to be an effective design and can be used in a wide range of applications.

scholarly journals Microfabrication Process-Driven Design, FEM Analysis and System Modeling of 3-DoF Drive Mode and 2-DoF Sense Mode Thermally Stable Non-Resonant MEMS Gyroscope

Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 862 ◽  
Author(s):  
Syed Ali Raza Bukhari ◽  
Muhammad Mubasher Saleem ◽  
Umar Shahbaz Khan ◽  
Amir Hamza ◽  
Javaid Iqbal ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Microelectromechanical Systems ◽  
System Modeling ◽  
Silicon On Insulator ◽  
System Level ◽  
Voltage Sensitivity ◽  
Thermally Stable ◽  
Sense Mode ◽  
Drive Mode ◽  
Mems Gyroscope

This paper presents microfabrication process-driven design of a multi-degree of freedom (multi-DoF) non-resonant electrostatic microelectromechanical systems (MEMS) gyroscope by considering the design constraints of commercially available low-cost and widely-used silicon-on-insulator multi-user MEMS processes (SOIMUMPs), with silicon as a structural material. The proposed design consists of a 3-DoF drive mode oscillator with the concept of addition of a collider mass which transmits energy from the drive mass to the passive sense mass. In the sense direction, 2-DoF sense mode oscillator is used to achieve dynamically-amplified displacement in the sense mass. A detailed analytical model for the dynamic response of MEMS gyroscope is presented and performance characteristics are validated through finite element method (FEM)-based simulations. The effect of operating air pressure and temperature variations on the air damping and resulting dynamic response is analyzed. The thermal stability of the design and corresponding effect on the mechanical and capacitive sensitivity, for an operating temperature range of −40 °C to 100 °C, is presented. The results showed that the proposed design is thermally stable, robust to environmental variations, and process tolerances with a wide operational bandwidth and high sensitivity. Moreover, a system-level model of the proposed gyroscope and its integration with the sensor electronics is presented to estimate the voltage sensitivity under the constraints of the readout electronic circuit.

Stability of Ring-Type MEMS Gyroscopes Subjected to Stochastic Angular Speed Fluctuation

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Samuel F. Asokanthan ◽  
Soroush Arghavan ◽  
Mohamed Bognash
Keyword(s):  
Angular Velocity ◽  
Degrees Of Freedom ◽  
Microelectromechanical Systems ◽  
Damping Ratio ◽  
Operating Conditions ◽  
System Stability ◽  
System Response ◽  
Ring Type ◽  
Mems Gyroscopes ◽  
The Stability

Effect of stochastic fluctuations in angular velocity on the stability of two degrees-of-freedom ring-type microelectromechanical systems (MEMS) gyroscopes is investigated. The governing stochastic differential equations (SDEs) are discretized using the higher-order Milstein scheme in order to numerically predict the system response assuming the fluctuations to be white noise. Simulations via Euler scheme as well as a measure of largest Lyapunov exponents (LLEs) are employed for validation purposes due to lack of similar analytical or experimental data. The response of the gyroscope under different noise fluctuation magnitudes has been computed to ascertain the stability behavior of the system. External noise that affect the gyroscope dynamic behavior typically results from environment factors and the nature of the system operation can be exerted on the system at any frequency range depending on the source. Hence, a parametric study is performed to assess the noise intensity stability threshold for a number of damping ratio values. The stability investigation predicts the form of threshold fluctuation intensity dependence on damping ratio. Under typical gyroscope operating conditions, nominal input angular velocity magnitude and mass mismatch appear to have minimal influence on system stability.

A Novel Design of the Device for Measuring Draw and Plug Forces

2012 ◽  
Vol 542-543 ◽  
pp. 1029-1032
Author(s):  
Ye Hu ◽  
Zhao Jun Yang ◽  
Ming Jun Xiang ◽  
Zi Chen Qiu ◽  
Chuan Gui Yang ◽  
...  
Keyword(s):  
Data Conversion ◽  
Memory Module ◽  
Novel Device ◽  
Working Principle ◽  
Tool Shank ◽  
Novel Design

The purpose of this paper is to present a novel device for measuring draw and plug forces, which is composed chiefly of a pull stud, a top modified tool shank, a middle modified tool shank, a down modified tool shank, and an end cover. The modified tool shank structure is proposed, and the working principle of the device for measuring draw and plug forces is demonstrated. Also, the data conversion and memory module and the circuit principle are investigated.

scholarly journals Towards a biomimetic gyroscope inspired by the fly's haltere using microelectromechanical systems technology

2014 ◽  
Vol 11 (99) ◽  
pp. 20140573 ◽  
Author(s):  
H. Droogendijk ◽  
R. A. Brookhuis ◽  
M. J. de Boer ◽  
R. G. P. Sanders ◽  
G. J. M. Krijnen
Keyword(s):  
Microelectromechanical Systems ◽  
Damping Ratio ◽  
Fast Response ◽  
Gyroscopic System ◽  
Drive Mode ◽  
Mems Gyroscope ◽  
Coriolis Forces ◽  
Mems Technology ◽  
Large Measurement ◽  
Theoretical Performance

Flies use so-called halteres to sense body rotation based on Coriolis forces for supporting equilibrium reflexes. Inspired by these halteres, a biomimetic gimbal-suspended gyroscope has been developed using microelectromechanical systems (MEMS) technology. Design rules for this type of gyroscope are derived, in which the haltere-inspired MEMS gyroscope is geared towards a large measurement bandwidth and a fast response, rather than towards a high responsivity. Measurements for the biomimetic gyroscope indicate a (drive mode) resonance frequency of about 550 Hz and a damping ratio of 0.9. Further, the theoretical performance of the fly's gyroscopic system and the developed MEMS haltere-based gyroscope is assessed and the potential of this MEMS gyroscope is discussed.

scholarly journals Investigation of an Autofocusing Method for Visible Aerial Cameras Based on Image Processing Techniques

2016 ◽  
Vol 2016 ◽  
pp. 1-12
Author(s):  
Zhichao Chen ◽  
Tao Zhang
Keyword(s):  
Image Processing ◽  
Image Processing Techniques ◽  
Accuracy Requirement ◽  
Aerospace Applications ◽  
Evaluation Functions ◽  
Focus Depth ◽  
Practical Engineering ◽  
Working Principle ◽  
Processing Techniques ◽  
Novel Design

In order to realize the autofocusing in aerial camera, an autofocusing system is established and its characteristics such as working principle and optical-mechanical structure and focus evaluation function are investigated. The reason for defocusing in aviation camera is analyzed and several autofocusing methods along with appropriate focus evaluation functions are introduced based on the image processing techniques. The proposed autofocusing system is designed and implemented using two CMOS detectors. The experiment results showed that the proposed method met the aviation camera focusing accuracy requirement, and a maximum focusing error of less than half of the focus depth is achieved. The system designed in this paper can find the optical imaging focal plane in real-time; as such, this novel design has great potential in practical engineering, especially aerospace applications.

scholarly journals MEMS Gyroscope Automatic Real-Time Mode-Matching Method Based on Phase-Shifted 45° Additional Force Demodulation

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 3001 ◽  
Author(s):  
Feng Bu ◽  
Dacheng Xu ◽  
Heming Zhao ◽  
Bo Fan ◽  
Mengmeng Cheng
Keyword(s):  
Real Time ◽  
Microelectromechanical Systems ◽  
Control Variable ◽  
Mode Frequency ◽  
Mode Matching ◽  
Sense Mode ◽  
Zero Bias ◽  
Real Time Mode ◽  
Additional Force ◽  
Force Signal

In order to solve the problem where existing mode-matching methods in microelectromechanical systems (MEMS) vibrating gyroscopes fail to meet real-time and reliability requirements, this paper presents a novel method to accomplish automatic and real-time mode-matching based on phase-shifted 45° additional force demodulation (45° AFD-RM). The phase-shifted 45° additional force signal has the same frequency as the quadrature force signal, but it is phase-shifted by 45° and applied to the sense mode. In addition, two-way phase-shifted 45° demodulations are used at the sense-mode detection output to obtain a phase metric that is independent of the Coriolis force and can reflect the mode-matching state. Then, this phase metric is used as a control variable to adaptively control the tuning voltage, so as to change the sense-mode frequency through the negative stiffness effect and ultimately achieve real-time mode-matching. Simulation and experimental results show that the proposed 45° AFD-RM method can achieve real-time matching. The mode frequency split is controlled within 0.1 Hz, and the gyroscope scale factor, zero-bias instability, and angle random walk are effectively improved.

scholarly journals Design and Analysis of a High-Gain and Robust Multi-DOF Electro-thermally Actuated MEMS Gyroscope

Micromachines ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 577 ◽  
Author(s):  
Muhammad Saqib ◽  
Muhammad Mubasher Saleem ◽  
Naveed Mazhar ◽  
Saif Awan ◽  
Umar Shahbaz Khan
Keyword(s):  
Resonant Frequency ◽  
Analytical Model ◽  
Actuation Voltage ◽  
High Gain ◽  
Sense Mode ◽  
Drive Mode ◽  
Mass System ◽  
Mems Gyroscope ◽  
Flat Region ◽  
Thermally Actuated

This paper presents the design and analysis of a multi degree of freedom (DOF) electro-thermally actuated non-resonant MEMS gyroscope with a 3-DOF drive mode and 1-DOF sense mode system. The 3-DOF drive mode system consists of three masses coupled together using suspension beams. The 1-DOF system consists of a single mass whose motion is decoupled from the drive mode using a decoupling frame. The gyroscope is designed to be operated in the flat region between the first two resonant peaks in drive mode, thus minimizing the effect of environmental and fabrication process variations on device performance. The high gain in the flat operational region is achieved by tuning the suspension beams stiffness. A detailed analytical model, considering the dynamics of both the electro-thermal actuator and multi-mass system, is developed. A parametric optimization is carried out, considering the microfabrication process constraints of the Metal Multi-User MEMS Processes (MetalMUMPs), to achieve high gain. The stiffness of suspension beams is optimized such that the sense mode resonant frequency lies in the flat region between the first two resonant peaks in the drive mode. The results acquired through the developed analytical model are verified with the help of 3D finite element method (FEM)-based simulations. The first three resonant frequencies in the drive mode are designed to be 2.51 kHz, 3.68 kHz, and 5.77 kHz, respectively. The sense mode resonant frequency is designed to be 3.13 kHz. At an actuation voltage of 0.2 V, the dynamically amplified drive mode gain in the sense mass is obtained to be 18.6 µm. With this gain, a capacitive change of 28.11   f F and 862.13   f F is achieved corresponding to the sense mode amplitude of 0.15   μ m and 4.5   μ m at atmospheric air pressure and in a vacuum, respectively.

scholarly journals Amplitude control system of drive-mode oscillations of MEMS gyroscopes

2019 ◽  
Vol 516 ◽  
pp. 012009
Author(s):  
T G Nesterenko ◽  
E S Barbin ◽  
P F Baranov ◽  
Lo Van Hao
Keyword(s):  
Control System ◽  
Drive Mode ◽  
Amplitude Control ◽  
Mems Gyroscopes
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