This book comprehensively and systematically introduces readers to the theories, structures, performance and applications of non-driven mechanical and non-driven micromechanical gyroscopes. The book is divided into three parts, the first of which mainly addresses mathematic models, precision, performance and operating error in non-driven mechanical gyroscopes. The second part focuses on the operating theory, error, phase shift and performance experiments involving non-driven micromechanical gyroscopes in rotating flight carriers, while the third part shares insights into the application of non-driven micromechanical gyroscopes in control systems for rotating flight carriers. The book offers a unique resource for all researchers and engineers who are interested in the use of inertial devices and automatic control systems for rotating flight carriers. It can also serve as a reference book for undergraduates, graduates and instructors in related fields at colleges and universities.
Presents the mathematical framework, technical language, and control systems know-how needed to design, develop, and instrument micro-scale whole-angle gyroscopes This comprehensive reference covers the technical fundamentals, mathematical framework, and common control strategies for degenerate mode gyroscopes, which are used in high-precision navigation applications. It explores various energy loss mechanisms and the effect of structural imperfections, along with requirements for continuous rate integrating gyroscope operation. It also provides information on the fabrication of MEMS whole-angle gyroscopes and the best methods of sustaining oscillations. Whole-Angle Gyroscopes: Challenges and Opportunities begins with a brief overview of the two main types of Coriolis Vibratory Gyroscopes (CVGs): non-degenerate mode gyroscopes and degenerate mode gyroscopes. It then introduces readers to the Foucault Pendulum analogy and a review of MEMS whole angle mode gyroscope development. Chapters cover: dynamics of whole-angle coriolis vibratory gyroscopes; fabrication of whole-angle coriolis vibratory gyroscopes; energy loss mechanisms of coriolis vibratory gyroscopes; and control strategies for whole-angle coriolis vibratory gyro- scopes. The book finishes with a chapter on conventionally machined micro-machined gyroscopes, followed by one on micro-wineglass gyroscopes. In addition, the book: Lowers barrier to entry for aspiring scientists and engineers by providing a solid understanding of the fundamentals and control strategies of degenerate mode gyroscopes Organizes mode-matched mechanical gyroscopes based on three classifications: wine-glass, ring/disk, and mass spring mechanical elements Includes case studies on conventionally micro-machined and 3-D micro-machined gyroscopes Whole-Angle Gyroscopes is an ideal book for researchers, scientists, engineers, and college/graduate students involved in the technology. It will also be of great benefit to engineers in control systems, MEMS production, electronics, and semi-conductors who work with inertial sensors.
Some years ago, silicon-based mechanical sensors, like pressure sensors, accelerometers and gyroscopes, started their successful advance. Every year, hundreds of millions of these devices are sold, mainly for medical and automotive applications. The airbag sensor on which research already started several decades ago at Stanford University can be found in every new car and has saved already numerous lives. Pressure sensors are also used in modern electronic blood pressure equipment. Many other mechanical sensors, mostly invisible to the public, perform useful functions in countless industrial and consumer products. The underlying physics and technology of silicon-based mechanical sensors is rather complex and is treated in numerous publications scattered throughout the literature. Therefore, a clear need existed for a handbook that thoroughly and systematically reviews the present basic knowledge on these devices. After a short introduction, Professor Bao discusses the main issues relevant to silicon-based mechanical sensors. First a thorough treatment of stress and strain in diaphragms and beams is presented. Next, vibration of mechanical structures is illuminated, followed by a chapter on air damping. These basic chapters are then succeeded by chapters in which capacitive and piezoresistive sensing techniques are amply discussed. The book concludes with chapters on commercially available pressure sensors, accelerometers and resonant sensors in which the above principles are applied. Everybody, involved in designing silicon-based mechanical sensors, will find a wealth of useful information in the book, assisting the designer in obtaining highly optimized devices.
This book provides the latest theoretical analysis and design methodologies of different types of Coriolis vibratory gyroscopes (CVG). Together, the chapters analyze different types of sensitive element designs and their kinematics, derivation of motion equations, analysis of sensitive elements dynamics in modulated and demodulated signals, calculation and optimization of main performance characteristics, and signal processing and control. Essential aspects of numerical simulation of CVG using Simulink® are also covered. This is an ideal book for graduate students, researchers, and engineers working in fields that require gyroscope application, including but not limited to: inertial sensors and systems, automotive and consumer electronics, small unmanned aircraft control systems, personal mobile navigation systems and related software development, and augmented and virtual reality systems.
The International Conference of Electronic Engineering and Information Science 2015 (ICEEIS 2015) was held on January 17-18, 2015, Harbin, China. This proceedings volume assembles papers from various researchers, engineers and educators engaged in the fields of electronic engineering and information science.The papers in this proceedings
This book introduces the key technologies in the manufacture of double-mass line vibrating silicon micromechanical gyroscope, respectively. The design of gyrostructure, detection technology, orthogonal correction technology, the influence of temperature and the design of measurement and control system framework are introduced in detail, with illustrations for easy understanding. It presents the principle, structure and related technology of silicon-based MEMS gyroscope. The content enlightens the researchers of silicon-based MEMS gyroscopes and gives readers a new understanding of the structural design of silicon-based gyroscopes and the design of dual-mass gyroscopes.
Micro-machined vibratory gyroscopes are very small devices (up to a few millimeters in dimension) that work based on Coriolis force coupling between two resonance modes. The small size, low power consumption, and cheap price make these sensors popular in automotive, gaming, smart phones, and robotics industries. These sensors referred to as MEMS (microelectromechanical system) gyroscopes are currently not used for navigation applications because due to their miniature size and imperfections in fabrication methods they do not have enough accuracy. In this thesis, we present methods in design and control algorithms for MEMS vibratory gyroscopes to cancel the effect of imperfections in fabrication and improve gyroscopes' performance. First chapter of this thesis is an introduction on MEMS vibratory gyroscopes and their principles and standard operations modes.The second chapter presents the structural design and analysis of a single-structure 3-axis MEMS gyroscope. The gyroscope has four resonant modes of interest and uses a decoupling mechanism whereby auxiliary masses are used to actuate the drive mode of the gyroscope in order to reduce drive-force coupling to sense modes' motion (one of the sources of errors in MEMS gyroscopes). The use of auxiliary masses results in a two degree-of-freedom (DOF) mechanism of the drive mode. To compare the effectiveness of using auxiliary masses two gyroscope types has been design one actuated from auxiliary masses (type A) and one actuated from major masses (type B). The two designs are simulated analytically to study the displacement of each mass in each design while comparing the force required to achieve that displacement for drive mode. Experimental data from fabricated devices show how using auxiliary masses will decrease drive force coupling and as a result improve the gyroscope's performance. Third chapter describes the operation of a high quality factor gyroscope in various regimes where electromechanical nonlinearities introduce different forms of amplitude-frequency (A-f) dependence. Experiments are conducted using an epitaxially-encapsulated 2 x 2 mm2 quad-mass gyroscope (QMG) with a quality factor of 85,000. The device exhibits third-order Duffing nonlinearity at low bias voltages (15 V) due to the mechanical nonlinearity in the flexures and at high bias voltages (35 V) due to third-order electrostatic nonlinearity. At intermediate voltages (26 V), these third-order nonlinearities cancel and the amplitude-frequency dependence is greatly reduced. A model is developed to demonstrate the connection between the electromechanical nonlinearities and the amplitude-frequency dependence, also known as the backbone curve. Gyroscope operation is demonstrated in each nonlinear operating regime and the key performance measures of the gyroscope's performance, angle random walk (ARW) and bias instability, are measured as a function of drive-mode vibration amplitude. While the bias instability is nearly independent of the drive-mode’s nonlinearity, we find that ARW increases when the third-order nonlinearities are minimized, and the decrease in ARW due to increase of amplitude is independent of drive mode's type of nonlinearity.In the fourth chapter we present a direct angle measurement method in gyroscopes. Towards the objective of direct angle measurement using a rate integrating gyroscope (RIG) without a minimum rate threshold and performance limited only by electrical and mechanical thermal noise, in this chapter we present the implementation of a generalized electronic feedback method for the compensation of MEMS gyroscope damping asymmetry (anisodamping) and stiffness asymmetry (anisoelasticity) on a stand-alone digital signal processing (DSP) platform. Using the new method, the precession angle dependent bias error and minimum rate threshold, two issues identified by Lynch for a MEMS RIG due to anisodamping are overcome. To minimize angle dependent bias, we augment the electronic feedback force of the amplitude regulator with a non-unity gain output distribution matrix selected to correct for anisodamping. Using this method, we have decreased the angle dependent bias error by a factor of 30, resulting a minimum rate threshold of 2.5 dps. To further improve RIG performance, an electronically-induced self-precession rate is incorporated and successfully demonstrated to lower the rate threshold.
This monograph collects and critically reviews the main results obtained by the scientific community in gyroscope technologies research field. It describes architectures, design techniques and fabrication technology of angular rate sensors proposed in literature. MEMS, MOEMS, optical and mechanical technologies are discussed together with achievable performance. The book also consideres future research trends aimed to cover special applications. The book is intended for researchers and Ph.D. students interested in modelling, design and fabrication of gyros. The book may be a useful education support in some university courses focused on gyro technologies.
