WorldWideScience

Sample records for gyroscopes

  1. Microelectromechanical gyroscope

    Science.gov (United States)

    Garcia, Ernest J.

    1999-01-01

    A gyroscope powered by an engine, all fabricated on a common substrate in the form of an integrated circuit. Preferably, both the gyroscope and the engine are fabricated in the micrometer domain, although in some embodiments of the present invention, the gyroscope can be fabricated in the millimeter domain. The engine disclosed herein provides torque to the gyroscope rotor for continuous rotation at varying speeds and direction. The present invention is preferably fabricated of polysilicon or other suitable materials on a single wafer using surface micromachining batch fabrication techniques or millimachining techniques that are well known in the art. Fabrication of the present invention is preferably accomplished without the need for assembly of multiple wafers which require alignment and bonding, and without piece-part assembly.

  2. Optical gyroscope

    Science.gov (United States)

    Seifollahi, Alireza

    It is said that future of the world is based on space exploration which leads us to think more about low cost and light weight instruments. Cheap and sensitive instruments should be de-signed and replace the expensive ones. One of the required instruments in space ships is gyroscope controls the direction of space ship. In this article I am going to give an idea to use optical properties in a new gyroscope which will be cheaper as well as more sensitive in com-pare with most of the being used normal gyroscope nowadays. This instrument uses an optical system to measure the angular changes in the direction of a space craft movements in any of the three axels. Any movement, even very small one, will move a crystal bulb which is lashed by some narrow elastic bands in a fixed box surrounded by three optical sources and light meters. Light meters measure the attitude and the angel of changes in the light beams going through the bulb which is related to the amount of changes in the space craft directions. The system will be very sensitive even against movement around its access. As an electro digital device in connection to a Main Process Unit (MPU) it can be used in Stability Augmentation System (SAS) in a space ship. The sensitivity rate of the instrument will be based on the quality and sensitivity of the light meters.

  3. Silicon micromachined vibrating gyroscopes

    Science.gov (United States)

    Voss, Ralf

    1997-09-01

    This work gives an overview of silicon micromachined vibrating gyroscopes. Market perspectives and fields of application are pointed out. The advantage of using silicon micromachining is discussed and estimations of the desired performance, especially for automobiles are given. The general principle of vibrating gyroscopes is explained. Vibrating silicon gyroscopes can be divided into seven classes. for each class the characteristic principle is presented and examples are given. Finally a specific sensor, based on a tuning fork for automotive applications with a sensitivity of 250(mu) V/degrees is described in detail.

  4. Topological Gyroscopic Metamaterials

    Science.gov (United States)

    Nash, Lisa Michelle

    Topological materials are generally insulating in their bulk, with protected conducting states on their boundaries that are robust against disorder and perturbation of material property. The existence of these conducting edge states is characterized by an integer topological invariant. Though the phenomenon was first discovered in electronic systems, recent years have shown that topological states exist in classical systems as well. In this thesis we are primarily concerned with the topological properties of gyroscopic materials, which are created by coupling networks of fast-spinning objects. Through a series of simulations, numerical calculations, and experiments, we show that these materials can support topological edge states. We find that edge states in these gyroscopic metamaterials bear the hallmarks of topology related to broken time reversal symmetry: they transmit excitations unidirectionally and are extremely robust against experimental disorder. We also explore requirements for topology by studying several lattice configurations and find that topology emerges naturally in gyroscopic systems.A simple prescription can be used to create many gyroscopic lattices. Though many of our gyroscopic networks are periodic, we explore amorphous point-sets and find that topology also emerges in these networks.

  5. Gyroscope Technology and Applications: A Review in the Industrial Perspective

    Directory of Open Access Journals (Sweden)

    Vittorio M. N. Passaro

    2017-10-01

    Full Text Available This paper is an overview of current gyroscopes and their roles based on their applications. The considered gyroscopes include mechanical gyroscopes and optical gyroscopes at macro- and micro-scale. Particularly, gyroscope technologies commercially available, such as Mechanical Gyroscopes, silicon MEMS Gyroscopes, Ring Laser Gyroscopes (RLGs and Fiber-Optic Gyroscopes (FOGs, are discussed. The main features of these gyroscopes and their technologies are linked to their performance.

  6. The development of micro-gyroscope technology

    International Nuclear Information System (INIS)

    Liu, Kai; Zhang, Weiping; Chen, Wenyuan; Li, Kai; Dai, Fuyan; Cui, Feng; Wu, Xiaosheng; Ma, Gaoyin; Xiao, Qijun

    2009-01-01

    This review reports an overview and development of micro-gyroscope. The review first presents different types of micro-gyroscopes. Micro-gyroscopes in this review are categorized into Coriolis gyroscope, levitated rotor gyroscope, Sagnac gyroscope, nuclear magnetic resonance (NMR) gyroscope according to the working principle. Different principles, structures, materials, fabrications and control technologies of micro-gyroscopes are analyzed. This review compares different classes of gyroscopes in the aspects such as fabrication method, detection axis, materials, size and so on. Finally, the review evaluates the key technologies on how to improve the precision and anti-jamming ability and to extend the available applications of the gyroscopes in the market and patents as well. (topical review)

  7. Ring mirror fiber laser gyroscope

    Science.gov (United States)

    Shalaby, Mohamed Y.; Khalil, Kamal; Afifi, Abdelrahman E.; Khalil, Diaa

    2017-02-01

    In this work we present a new architecture for a laser gyroscope based on the use of a Sagnac fiber loop mirror. The proposed system has the unique property that its scale factor can be increased by increasing the gain of the optical amplifier used in the system as demonstrated experimentally using standard single mode fiber and explained physically by the system operation. The proposed gyroscope system is also capable of identifying the direction of rotation. This new structure opens the door for a new category of low cost optical gyroscopes.

  8. Fiberless Optical Gyroscope, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a radical new approach for to the design and fabrication of a fiber-less Interferometric Optical Gyroscope (IOG) that enables the production of a...

  9. Fast Light Optical Gyroscopes

    Science.gov (United States)

    Smith, David D.

    2015-01-01

    Next-generation space missions are currently constrained by existing spacecraft navigation systems which are not fully autonomous. These systems suffer from accumulated dead-reckoning errors and must therefore rely on periodic corrections provided by supplementary technologies that depend on line-of-sight signals from Earth, satellites, or other celestial bodies for absolute attitude and position determination, which can be spoofed, incorrectly identified, occluded, obscured, attenuated, or insufficiently available. These dead-reckoning errors originate in the ring laser gyros themselves, which constitute inertial measurement units. Increasing the time for standalone spacecraft navigation therefore requires fundamental improvements in gyroscope technologies. One promising solution to enhance gyro sensitivity is to place an anomalous dispersion or fast light material inside the gyro cavity. The fast light essentially provides a positive feedback to the gyro response, resulting in a larger measured beat frequency for a given rotation rate as shown in figure 1. Game Changing Development has been investing in this idea through the Fast Light Optical Gyros (FLOG) project, a collaborative effort which began in FY 2013 between NASA Marshall Space Flight Center (MSFC), the U.S. Army Aviation and Missile Research, Development, and Engineering Center (AMRDEC), and Northwestern University. MSFC and AMRDEC are working on the development of a passive FLOG (PFLOG), while Northwestern is developing an active FLOG (AFLOG). The project has demonstrated new benchmarks in the state of the art for scale factor sensitivity enhancement. Recent results show cavity scale factor enhancements of approx.100 for passive cavities.

  10. The Development of Micromachined Gyroscope Structure and Circuitry Technology

    Directory of Open Access Journals (Sweden)

    Dunzhu Xia

    2014-01-01

    Full Text Available This review surveys micromachined gyroscope structure and circuitry technology. The principle of micromachined gyroscopes is first introduced. Then, different kinds of MEMS gyroscope structures, materials and fabrication technologies are illustrated. Micromachined gyroscopes are mainly categorized into micromachined vibrating gyroscopes (MVGs, piezoelectric vibrating gyroscopes (PVGs, surface acoustic wave (SAW gyroscopes, bulk acoustic wave (BAW gyroscopes, micromachined electrostatically suspended gyroscopes (MESGs, magnetically suspended gyroscopes (MSGs, micro fiber optic gyroscopes (MFOGs, micro fluid gyroscopes (MFGs, micro atom gyroscopes (MAGs, and special micromachined gyroscopes. Next, the control electronics of micromachined gyroscopes are analyzed. The control circuits are categorized into typical circuitry and special circuitry technologies. The typical circuitry technologies include typical analog circuitry and digital circuitry, while the special circuitry consists of sigma delta, mode matching, temperature/quadrature compensation and novel special technologies. Finally, the characteristics of various typical gyroscopes and their development tendency are discussed and investigated in detail.

  11. The Gravity Probe B gyroscope

    International Nuclear Information System (INIS)

    Buchman, S; Lipa, J A; Keiser, G M; Muhlfelder, B; Turneaure, J P

    2015-01-01

    The Gravity Probe B (GP-B) gyroscope, a unique cryogenically operated mechanical sensor, was used on-orbit to independently test two predictions of general relativity (GR). Here, we describe the development and performance of the GP-B gyroscope, its geometry and fabrication, spin-up and vacuum approach, magnetic considerations, and static charge management. The history of electrically suspended gyroscopes puts the current work in context. Fabrication and ground testing of the GP-B gyroscope are detailed, followed by a review of on-orbit initialization, calibration, operation, and performance. We find that the performance was degraded relative to the mission goals, but was still sufficient to provide excellent new tests of GR. The degradation is partially due to the existence of gyroscope torques due to an unanticipated interaction between patch potentials on the rotor and the housing. We discuss these patch potentials and describe the effect of related torques on gyro drift. It was essential to include models for the effects due to the patch potentials in the complete data analysis model to yield determinations of the two GR effects. (paper)

  12. GEC Ferranti piezo vibratory gyroscope

    Science.gov (United States)

    Nuttall, J. D.

    1993-01-01

    Prototypes of a piezo-electric vibratory angular rate transducer (gyroscope) (PVG) have been constructed and evaluated. The construction is on the lines suggested by Burdess. The sensitive element is a cylinder of radially poled piezo-electric ceramic. The cylinder is metallized inside and out, and the outer metallization is divided into eight electrodes. The metallization on the inside is earthed. A phase locked loop, using pairs of the electrodes, causes the cylinder to vibrate in one of its two fundamental, degenerate modes. In the presence of rotation, some of the vibration is coupled into the outer mode. This can be detected, or suppressed with a closed-up technique and provides a measure of rotation rate. The gyroscope provides a number of advantages over rotating mass and optical instruments: low size and mass, lower power consumption, potentially high reliability, potentially good dormancy, low cost and high maximum rate.

  13. Gravity Probe B Gyroscope Rotor

    Science.gov (United States)

    2003-01-01

    The Gravity Probe B (GP-B) is the relativity experiment developed at Stanford University to test two extraordinary predictions of Albert Einstein's general theory of relativity. The experiment will measure, very precisely, the expected tiny changes in the direction of the spin axes of four gyroscopes contained in an Earth-orbiting satellite at a 400-mile altitude. So free are the gyroscopes from disturbance that they will provide an almost perfect space-time reference system. They will measure how space and time are very slightly warped by the presence of the Earth, and, more profoundly, how the Earth's rotation very slightly drags space-time around with it. These effects, though small for the Earth, have far-reaching implications for the nature of matter and the structure of the Universe. This photograph is a close up of a niobium-coated gyroscope motor and its housing halves. GP-B is among the most thoroughly researched programs ever undertaken by NASA. This is the story of a scientific quest in which physicists and engineers have collaborated closely over many years. Inspired by their quest, they have invented a whole range of technologies that are already enlivening other branches of science and engineering. Launched April 20, 2004 , the GP-B program was managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University along with major subcontractor Lockheed Martin Corporation. (Image credit to Don Harley.)

  14. Gyroscopic management as added value for management

    NARCIS (Netherlands)

    John Vinke

    2012-01-01

    In recent publications in International Journals in 2010 and 2011, I described the phenomenon of a new approach to education and training called ‘Gyroscopic Management’ (See list publications). To give the reader an insight and overview of this, I will introduce and explain this gyroscopic

  15. GYROSCOPIC MANAGEMENT AND GENERATION Y

    Directory of Open Access Journals (Sweden)

    Orhei Loredana

    2012-12-01

    Full Text Available In the professional field of business and management there is still little research done on the possibility if the Generation Y members (born between 1980 and 2000, which are the managers off the future, need a different approach in education and training to be prepared for the future. The authors will explain how a new didactical approach in business and management called “Gyroscopic Management” can prepare these new managers to be of added value for the business. This specific approach was the start in 2007 of a specific (international HRQM Bachelor study programme at Arnhem Business School, HAN University in the Netherlands. During this study programme, students are confronting this specific training and didactical approach with characteristics as self-reliance, self-study, and Socratic dialogue, ethical and “gyroscopic” management. The programme has a clear vision and mission and didactical approach that triggers the above-mentioned elements. The approach focuses on the need for development of specific competencies like “Intercultural adaptability”, “International business awareness” and “Social entrepreneurship” as added to the existing competencies needed for a Bachelor level in business and management education. As researchers, lecturers and trainers, the authors used and researched this approach during many lectures, seminars, trainings and workshops in the last years at Universities in Romania and The Netherlands. The authors present the characteristics of the members of the new Y generation and relate them to main elements of gyroscopic management as practice and the results of this practice for students. For this, the authors did a so-called “Grounded action research”, from 2009 until 2012, among students of business and management studies. Further, the research was supported by focus groups over the same period. The authors have the opinion that this research is

  16. Carbon Nanotube Tape Vibrating Gyroscope

    Science.gov (United States)

    Tucker, Dennis Stephen (Inventor)

    2016-01-01

    A vibrating gyroscope includes a piezoelectric strip having length and width dimensions. The piezoelectric strip includes a piezoelectric material and carbon nanotubes (CNTs) substantially aligned and polled along the strip's length dimension. A spindle having an axis of rotation is coupled to the piezoelectric strip. The axis of rotation is parallel to the strip's width dimension. A first capacitance sensor is mechanically coupled to the spindle for rotation therewith. The first capacitance sensor is positioned at one of the strip's opposing ends and is spaced apart from one of the strip's opposing faces. A second capacitance sensor is mechanically coupled to the spindle for rotation therewith. The second capacitance sensor is positioned at another of the strip's opposing ends and is spaced apart from another of the strip's opposing faces. A voltage source applies an AC voltage to the piezoelectric strip.

  17. Integrated microelectromechanical gyroscope under shock loads

    Science.gov (United States)

    Nesterenko, T. G.; Koleda, A. N.; Barbin, E. S.

    2018-01-01

    The paper presents a new design of a shock-proof two-axis microelectromechanical gyroscope. Without stoppers, the shock load enables the interaction between the silicon sensor elements. Stoppers were installed in the gyroscope to prevent the contact interaction between electrodes and spring elements with fixed part of the sensor. The contact of stoppers occurs along the plane, thereby preventing the system from serious contact stresses. The shock resistance of the gyroscope is improved by the increase in its eigenfrequency at which the contact interaction does not occur. It is shown that the shock load directed along one axis does not virtually cause the movement of sensing elements along the crosswise axes. Maximum stresses observed in the proposed gyroscope at any loading direction do not exceed the value allowable for silicon.

  18. MEMS Gyroscope with Interferometric Detection, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is a novel MEMS gyroscope that uses micro-interferometric detection to measure the motion of the proof mass. Using an interferometric...

  19. Model Design of Piezoelectric Micromachined Modal Gyroscope

    Directory of Open Access Journals (Sweden)

    Xiaojun Hu

    2011-01-01

    Full Text Available This paper reports a novel kind of solid-state microgyroscope, which is called piezoelectric micromachined modal gyroscope (PMMG. PMMG has large stiffness and robust resistance to shake and strike because there is no evident mass-spring component in its structure. This work focused on quantitative optimization of the gyroscope, which is still blank for such gyroscope. The modal analysis by the finite element method (FEM was firstly conducted. A set of quantitative indicators were developed to optimize the operation mode. By FEM, the harmonic analysis was conducted to find the way to efficiently actuate the operational mode needed. The optimal configuration of driving electrodes was obtained. At last, the Coriolis analysis was conducted to show the relation between angular velocity and differential output voltage by the Coriolis force under working condition. The results obtained in this paper provide theoretical basis for realizing this novel kind of micromachined gyroscope.

  20. Nonlinear oscillations in coriolis based gyroscopes

    Directory of Open Access Journals (Sweden)

    Dag Kristiansen

    1999-01-01

    Full Text Available In this paper we model and analyze nonlinear oscillations which are known to exist in some Coriolis based gyroscopes due to large amplitude excitation in the drive loop. A detailed derivation of a dynamic model for a cylinder gyroscope which includes geometric nonlinearities is given, and energy transfer between the system's modes are analyzed using perturbation theory and by proposing a simplified model. The model is also simulated, and the results are shown to give an accurate description of the experimental results. This work is done in order to gain a better understanding of the gyroscope's dynamics, and is intended to be a starting point for designing nonlinear observers and vibration controllers for the gyroscope in order to increase the performance.

  1. Fabrication of a novel quartz micromachined gyroscope

    Science.gov (United States)

    Xie, Liqiang; Xing, Jianchun; Wang, Haoxu; Wu, Xuezhong

    2015-04-01

    A novel quartz micromachined gyroscope is proposed in this paper. The novel gyroscope is realized by quartz anisotropic wet etching and 3-dimensional electrodes deposition. In the quartz wet etching process, the quality of Cr/Au mask films affecting the process are studied by experiment. An excellent mask film with 100 Å Cr and 2000 Å Au is achieved by optimization of experimental parameters. Crystal facets after etching seriously affect the following sidewall electrodes deposition process and the structure's mechanical behaviours. Removal of crystal facets is successfully implemented by increasing etching time based on etching rate ratios between facets and crystal planes. In the electrodes deposition process, an aperture mask evaporation method is employed to prepare electrodes on 3-dimensional surfaces of the gyroscope structure. The alignments among the aperture masks are realized by the ABM™ Mask Aligner System. Based on the processes described above, a z-axis quartz gyroscope is fabricated successfully.

  2. Hemispherical Resonator Gyroscope Accuracy Analysis Under Temperature Influence

    Directory of Open Access Journals (Sweden)

    Boran LI

    2014-06-01

    Full Text Available Frequency splitting of hemispherical resonator gyroscope will change as system operating temperature changes. This phenomenon leads to navigation accuracy of hemispherical resonator gyroscope reduces. By researching on hemispherical resonator gyroscope dynamical model and its frequency characteristic, the frequency splitting formula and the precession angle formula of gyroscope vibrating mode based on hemispherical resonator gyroscope dynamic equation parameters are derived. By comparison, gyroscope precession angle deviation caused by frequency splitting can be obtained. Based on analysis of temperature variation against gyroscope resonator, the design of hemispherical resonator gyroscope feedback controller under temperature variation conditions is researched and the maximum theoretical fluctuation of gyroscope dynamical is determined by using a numerical analysis example.

  3. A novel differential frequency micro-gyroscope

    KAUST Repository

    Nayfeh, A. H.; Abdel-Rahman, E. M.; Ghommem, M.

    2013-01-01

    We present a frequency-domain method to measure angular speeds using electrostatic micro-electro-mechanical system actuators. Towards this end, we study a single-axis gyroscope made of a micro-cantilever and a proof-mass coupled to two fixed

  4. Relative Pose Estimation Algorithm with Gyroscope Sensor

    Directory of Open Access Journals (Sweden)

    Shanshan Wei

    2016-01-01

    Full Text Available This paper proposes a novel vision and inertial fusion algorithm S2fM (Simplified Structure from Motion for camera relative pose estimation. Different from current existing algorithms, our algorithm estimates rotation parameter and translation parameter separately. S2fM employs gyroscopes to estimate camera rotation parameter, which is later fused with the image data to estimate camera translation parameter. Our contributions are in two aspects. (1 Under the circumstance that no inertial sensor can estimate accurately enough translation parameter, we propose a translation estimation algorithm by fusing gyroscope sensor and image data. (2 Our S2fM algorithm is efficient and suitable for smart devices. Experimental results validate efficiency of the proposed S2fM algorithm.

  5. Coriolis vibratory gyroscopes theory and design

    CERN Document Server

    Apostolyuk, Vladislav

    2016-01-01

    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.

  6. What forces act in relativistic gyroscope precession?

    Science.gov (United States)

    Semerák, Oldrich

    1996-11-01

    The translation of the relativistic motion into the language of forces, proposed by the author (1995, Nuovo Cimento B 110 973), is employed to interpret the gyroscope precession in general relativity. The precession is referred to the comoving Frenet triad built up along the projection of the gyroscope's trajectory onto the 3-space of the local hypersurface-orthogonal observer. The contributions of the centrifugal, the gravitational and the dragging + Coriolis forces are identified respectively with the Thomas, the geodetic, and the gravitomagnetic components of precession. Explicit expressions are given for several simple types of motion in the Kerr (or simpler) field in order to show that the general formulae obtained are not only very simple, but also yield clear results in accord with intuition in concrete situations.

  7. Quantum gyroscope based on Berry phase of spins in diamond

    Science.gov (United States)

    Song, Xuerui; Wang, Liujun; Diao, Wenting; Duan, Chongdi

    2018-02-01

    Gyroscope is the crucial sensor of the inertial navigation system, there is always high demand to improve the sensitivity and reduce the size of the gyroscopes. Using the NV center electronic spin and nuclear spin qubits in diamond, we introduce the research of new types of quantum gyroscopes based on the Berry phase shifts of the spin states during the rotation of the sensor systems. Compared with the performance of the traditional MEMS gyroscope, the sensitivity of the new types of quantum gyroscopes was highly improved and the spatial resolution was reduced to nano-scale. With the help of micro-manufacturing technology in the semiconductor industry, the quantum gyroscopes introduced here can be further integrated into chip-scale sensors.

  8. Scale factor measure method without turntable for angular rate gyroscope

    Science.gov (United States)

    Qi, Fangyi; Han, Xuefei; Yao, Yanqing; Xiong, Yuting; Huang, Yuqiong; Wang, Hua

    2018-03-01

    In this paper, a scale factor test method without turntable is originally designed for the angular rate gyroscope. A test system which consists of test device, data acquisition circuit and data processing software based on Labview platform is designed. Taking advantage of gyroscope's sensitivity of angular rate, a gyroscope with known scale factor, serves as a standard gyroscope. The standard gyroscope is installed on the test device together with a measured gyroscope. By shaking the test device around its edge which is parallel to the input axis of gyroscope, the scale factor of the measured gyroscope can be obtained in real time by the data processing software. This test method is fast. It helps test system miniaturized, easy to carry or move. Measure quarts MEMS gyroscope's scale factor multi-times by this method, the difference is less than 0.2%. Compare with testing by turntable, the scale factor difference is less than 1%. The accuracy and repeatability of the test system seems good.

  9. The Anatomy of the Gyroscope. Part 3

    Science.gov (United States)

    1990-03-01

    parts of the optical train by gyroscopic means; one of the first is that of JENSEN 1JS 2829557 (1958) who proposes a Porro - prism binocular telescope...to the ideas of JENSEN using Porro - prisms but we have neglected until now to refer to the work of KAESTNER who using porro - prisms and counterweights...CLEMENCE G.M. DYNAMICS OP THE SOLAR SYSTEM IBID pp. 2.60-2.68 ** See N.M.R. nuclear magnetic resonance , discovered 1945. ABRAGAM. A and GOLDMAN. M

  10. Fiber optic gyroscopes for vehicle navigation systems

    Science.gov (United States)

    Kumagai, Tatsuya; Soekawa, Hirokazu; Yuhara, Toshiya; Kajioka, Hiroshi; Oho, Shigeru; Sonobe, Hisao

    1994-03-01

    Fiber optic gyroscopes (FOGs) have been developed for vehicle navigation systems and are used in Toyota Motor Corporation models Mark II, Chaser and Cresta in Japan. Use of FOGs in these systems requires high reliability under a wide range of conditions, especially in a temperature range between -40 and 85 degree(s)C. In addition, a high cost-performance ratio is needed. We have developed optical and electrical systems that are inexpensive and can perform well. They are ready to be mass-produced. FOGs have already been installed in luxury automobiles, and will soon be included in more basic vehicles. We have developed more inexpensive FOGs for this purpose.

  11. Dynamics and control of vibratory gyroscopes with special spherical symmetry

    CSIR Research Space (South Africa)

    Shatalov, M

    2006-01-01

    Full Text Available It was shown in 1985 by Acad. V. Zhuravlev that the angular rate of a pure vibrating mode excited in a vibratory gyroscope with spherical symmetry is proportional to an inertial angular rate of the gyroscope. The effect is three dimensional...

  12. Structure optimization and simulation analysis of the quartz micromachined gyroscope

    Directory of Open Access Journals (Sweden)

    Xuezhong Wu

    2014-02-01

    Full Text Available Structure optimization and simulation analysis of the quartz micromachined gyroscope are reported in this paper. The relationships between the structure parameters and the frequencies of work mode were analysed by finite element analysis. The structure parameters of the quartz micromachined gyroscope were optimized to reduce the difference between the frequencies of the drive mode and the sense mode. The simulation results were proved by testing the prototype gyroscope, which was fabricated by micro-electromechanical systems (MEMS technology. Therefore, the frequencies of the drive mode and the sense mode can match each other by the structure optimization and simulation analysis of the quartz micromachined gyroscope, which is helpful in the design of the high sensitivity quartz micromachined gyroscope.

  13. A novel differential frequency micro-gyroscope

    KAUST Repository

    Nayfeh, A. H.

    2013-07-10

    We present a frequency-domain method to measure angular speeds using electrostatic micro-electro-mechanical system actuators. Towards this end, we study a single-axis gyroscope made of a micro-cantilever and a proof-mass coupled to two fixed electrodes. The gyroscope possesses two orthogonal axes of symmetry and identical flexural mode shapes along these axes. We develop the equations of motion describing the coupled bending modes in the presence of electrostatic and Coriolis forces. Furthermore, we derive a consistent closed-form higher-order expression for the natural frequencies of the coupled flexural modes. The closed-form expression is verified by comparing its results to those obtained from numerical integration of the equations of motion. We find that rotations around the beam axis couple each pair of identical bending modes to produce a pair of global modes. They also split their common natural frequency into a pair of closely spaced natural frequencies. We propose the use of the difference between this pair of frequencies, which is linearly proportional to the speed of rotation around the beam axis, as a detector for the angular speed.

  14. Fibre optic gyroscopes for space use

    Science.gov (United States)

    Faussot, Nicolas; Cottreau, Yann; Hardy, Guillaume; Simonpietri, Pascal; Gaiffe, Thierry

    2017-11-01

    Among the technologies available for gyroscopes usable in space, the Fibre Optic Gyroscope (FOG) technology appears to be the most suitable: no moving parts, very good lifetime, low power consumption, very low random walk, arbitrarily low angular resolution and very good behaviour in radiations and vacuum. Benefiting from more than ten years of experience with this technology, Ixsea (formerly the Navigation Division of Photonetics) is developing space FOG under both CNES and ESA contracts since many years. In the 1996-1998 period, two space FOG demonstrators in the 0,01°/h class were manufactured, including an optical head (optic and optoelectronic part) designed for space use and a standard ground electronics. Beyond the demonstration of the specified FOG performances, the behaviour of the optical head has been validated for use in typical space environment: vibrations, shocks, radiations (up to 50 krad) and thermal vacuum. Since the beginning of 1999, Ixsea is developing a space electronics in order to manufacture two complete space FOG. The first one entered in qualification in October. The second one will be delivered beginning of next year, it will be used in a CNES attitude measurement experiment (MAGI) onboard the FrenchBrazilian Microsatellite (FBM) partly dedicated to technology evaluation.

  15. A superconducting gyroscope to test Einstein's general theory of relativity

    Science.gov (United States)

    Everitt, C. W. F.

    1978-01-01

    Schiff (1960) proposed a new test of general relativity based on measuring the precessions of the spin axes of gyroscopes in earth orbit. Since 1963 a Stanford research team has been developing an experiment to measure the two effects calculated by Schiff. The gyroscope consists of a uniform sphere of fused quartz 38 mm in diameter, coated with superconductor, electrically suspended and spinning at about 170 Hz in vacuum. The paper describes the proposed flight apparatus and the current state of development of the gyroscope, including techniques for manufacturing and measuring the gyro rotor and housing, generating ultralow magnetic fields, and mechanizing the readout.

  16. MEMS Gyroscopes Based on Acoustic Sagnac Effect

    Directory of Open Access Journals (Sweden)

    Yuanyuan Yu

    2016-12-01

    Full Text Available This paper reports on the design, fabrication and preliminary test results of a novel microelectromechanical systems (MEMS device—the acoustic gyroscope. The unique operating mechanism is based on the “acoustic version” of the Sagnac effect in fiber-optic gyros. The device measures the phase difference between two sound waves traveling in opposite directions, and correlates the signal to the angular velocity of the hosting frame. As sound travels significantly slower than light and develops a larger phase change within the same path length, the acoustic gyro can potentially outperform fiber-optic gyros in sensitivity and form factor. It also promises superior stability compared to vibratory MEMS gyros as the design contains no moving parts and is largely insensitive to mechanical stress or temperature. We have carried out systematic simulations and experiments, and developed a series of processes and design rules to implement the device.

  17. Solid-state ring laser gyroscope

    Science.gov (United States)

    Schwartz, S.

    The ring laser gyroscope is a rotation sensor used in most kinds of inertial navigation units. It usually consists in a ring cavity filled with a mixture of helium and neon, together with high-voltage pumping electrodes. The use of a gaseous gain medium, while resulting naturally in a stable bidirectional regime enabling rotation sensing, is however the main industrially limiting factor for the ring laser gyroscopes in terms of cost, reliability and lifetime. We study in this book the possibility of substituting for the gaseous gain medium a solid-state medium (diode-pumped Nd-YAG). For this, a theoretical and experimental overview of the lasing regimes of the solid-state ring laser is reported. We show that the bidirectional emission can be obtained thanks to a feedback loop acting on the states of polarization and inducing differential losses proportional to the difference of intensity between the counterpropagating modes. This leads to the achievement of a solid-state ring laser gyroscope, whose frequency response is modified by mode coupling effects. Several configurations, either mechanically or optically based, are then successively studied, with a view to improving the quality of this frequency response. In particular, vibration of the gain crystal along the longitudinal axis appears to be a very promising technique for reaching high inertial performances with a solid-state ring laser gyroscope. Gyrolaser à état solide. Le gyrolaser est un capteur de rotation utilisé dans la plupart des centrales de navigation inertielle. Dans sa forme usuelle, il est constitué d'une cavité laser en anneau remplie d'un mélange d'hélium et de néon pompé par des électrodes à haute tension. L'utilisation d'un milieu amplificateur gazeux, si elle permet de garantir naturellement le fonctionnement bidirectionnel stable nécessaire à la mesure des rotations, constitue en revanche la principale limitation industrielle des gyrolasers actuels en termes de coût, fiabilit

  18. Videometrics-based Detection of Vibration Linearity in MEMS Gyroscope

    Directory of Open Access Journals (Sweden)

    Yong Zhou

    2011-05-01

    Full Text Available MEMS gyroscope performs as a sort of sensor to detect angular velocity, with diverse applications in engineering including vehicle and intelligent traffic etc. A balanced vibration of driving module excited by electrostatic driving signal is the base MEMS gyroscope's performance. In order to analyze the linear property of vibration in MEMS Gyroscope, a method of computer vision measuring is applied with the help of high-speed vidicon to obtain video of linear vibration of driving module in gyroscope, under the driving voltage signal of inherent frequency and amplitude linearly increasing. By means of image processing, target identifying, and motion parameter extracting from the obtained video, vibration curve with time variation is acquired. And then, linearity of this vibration system can be analyzed by focusing on the amplitude value of vibration responding to the amplitude variation of driving voltage signal.

  19. Vibratory gyroscopes : identification of mathematical model from test data

    CSIR Research Space (South Africa)

    Shatalov, MY

    2007-05-01

    Full Text Available Simple mathematical model of vibratory gyroscopes imperfections is formulated, which includes anisotropic damping and variation of mass-stiffness parameters and their harmonics. The method of identification of parameters of the mathematical model...

  20. Fast-light Enhanced Fiber Gyroscope, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Current state-of-the-art navigation systems incorporate optical gyroscopes and optical accelerometers as inertial sensors. These devices contain no moving parts and...

  1. Non-driven micromechanical gyroscopes and their applications

    CERN Document Server

    Zhang, Fuxue; Wang, Guosheng

    2018-01-01

    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.

  2. Resonant microsphere gyroscope based on a double Faraday rotator system.

    Science.gov (United States)

    Xie, Chengfeng; Tang, Jun; Cui, Danfeng; Wu, Dajin; Zhang, Chengfei; Li, Chunming; Zhen, Yongqiu; Xue, Chenyang; Liu, Jun

    2016-10-15

    The resonant microsphere gyroscope is proposed based on a double Faraday rotator system for the resonant microsphere gyroscope (RMSG) that is characterized by low insertion losses and does not destroy the reciprocity of the gyroscope system. Use of the echo suppression structure and the orthogonal polarization method can effectively inhibit both the backscattering noise and the polarization error, and reduce them below the system sensitivity limit. The resonance asymmetry rate dropped from 34.2% to 2.9% after optimization of the backscattering noise and the polarization noise, which greatly improved the bias stability and the scale factor linearity of the proposed system. Additionally, based on the optimum parameters for the double Faraday rotator system, a bias stability of 0.04°/s has been established for an integration time of 10 s in 1000 s in a resonator microsphere gyroscope using a microsphere resonator with a diameter of 1 mm and a Q of 7.2×106.

  3. Modeling and optimizing of the random atomic spin gyroscope drift based on the atomic spin gyroscope

    Energy Technology Data Exchange (ETDEWEB)

    Quan, Wei; Lv, Lin, E-mail: lvlinlch1990@163.com; Liu, Baiqi [School of Instrument Science and Opto-Electronics Engineering, Beihang University, Beijing 100191 (China)

    2014-11-15

    In order to improve the atom spin gyroscope's operational accuracy and compensate the random error caused by the nonlinear and weak-stability characteristic of the random atomic spin gyroscope (ASG) drift, the hybrid random drift error model based on autoregressive (AR) and genetic programming (GP) + genetic algorithm (GA) technique is established. The time series of random ASG drift is taken as the study object. The time series of random ASG drift is acquired by analyzing and preprocessing the measured data of ASG. The linear section model is established based on AR technique. After that, the nonlinear section model is built based on GP technique and GA is used to optimize the coefficients of the mathematic expression acquired by GP in order to obtain a more accurate model. The simulation result indicates that this hybrid model can effectively reflect the characteristics of the ASG's random drift. The square error of the ASG's random drift is reduced by 92.40%. Comparing with the AR technique and the GP + GA technique, the random drift is reduced by 9.34% and 5.06%, respectively. The hybrid modeling method can effectively compensate the ASG's random drift and improve the stability of the system.

  4. Magnetometer and Gyroscope Calibration Method with Level Rotation

    Directory of Open Access Journals (Sweden)

    Zongkai Wu

    2018-03-01

    Full Text Available Micro electro mechanical system (MEMS gyroscopes and magnetometers are usually integrated into a sensor module or chip and widely used in a variety of applications. In existing integrated gyroscope and magnetometer calibration methods, rotation in all possible orientations is a necessary condition for a good calibration result. However, rotation around two or more axes is difficult to attain, as it is limited by the range of movement of vehicles such as cars, ships, or planes. To solve this problem, this paper proposes an integrated magnetometer and gyroscope calibration method with level rotation. The proposed method presents a redefined magnetometer output model using level attitude. New gyroscope and magnetometer calibration models are then deduced. In addition, a simplified cubature Kalman filter (CKF is established to estimate calibration parameters. This method possesses important value for application in actual systems, as it only needs level rotation for real-time calibration of gyroscopes and magnetometers. Theoretical analysis and test results verify the validity and feasibility of this method.

  5. Gyroscope precession in special and general relativity from basic principles

    Science.gov (United States)

    Jonsson, Rickard M.

    2007-05-01

    In special relativity a gyroscope that is suspended in a torque-free manner will precess as it is moved along a curved path relative to an inertial frame S. We explain this effect, which is known as Thomas precession, by considering a real grid that moves along with the gyroscope, and that by definition is not rotating as observed from its own momentary inertial rest frame. From the basic properties of the Lorentz transformation we deduce how the form and rotation of the grid (and hence the gyroscope) will evolve relative to S. As an intermediate step we consider how the grid would appear if it were not length contracted along the direction of motion. We show that the uncontracted grid obeys a simple law of rotation. This law simplifies the analysis of spin precession compared to more traditional approaches based on Fermi transport. We also consider gyroscope precession relative to an accelerated reference frame and show that there are extra precession effects that can be explained in a way analogous to the Thomas precession. Although fully relativistically correct, the entire analysis is carried out using three-vectors. By using the equivalence principle the formalism can also be applied to static spacetimes in general relativity. As an example, we calculate the precession of a gyroscope orbiting a static black hole.

  6. Compact fiber optic gyroscopes for platform stabilization

    Science.gov (United States)

    Dickson, William C.; Yee, Ting K.; Coward, James F.; McClaren, Andrew; Pechner, David A.

    2013-09-01

    SA Photonics has developed a family of compact Fiber Optic Gyroscopes (FOGs) for platform stabilization applications. The use of short fiber coils enables the high update rates required for stabilization applications but presents challenges to maintain high performance. We are able to match the performance of much larger FOGs by utilizing several innovative technologies. These technologies include source noise reduction to minimize Angular Random Walk (ARW), advanced digital signal processing that minimizes bias drift at high update rates, and advanced passive thermal packaging that minimizes temperature induced bias drift while not significantly affecting size, weight, or power. In addition, SA Photonics has developed unique distributed FOG packaging technologies allowing the FOG electronics and photonics to be packaged remotely from the sensor head or independent axis heads to minimize size, weight, and power at the sensing location(s). The use of these technologies has resulted in high performance, including ARW less than 0.001 deg/rt-hr and bias drift less than 0.004 deg/hr at an update rate of 10 kHz, and total packaged volume less than 30 cu. in. for a 6 degree of freedom FOG-based IMU. Specific applications include optical beam stabilization for LIDAR and LADAR, beam stabilization for long-range free-space optical communication, Optical Inertial Reference Units for HEL stabilization, and Ka band antenna pedestal pointing and stabilization. The high performance of our FOGs also enables their use in traditional navigation and positioning applications. This paper will review the technologies enabling our high-performance compact FOGs, and will provide performance test results.

  7. A comparative analysis of modal motions for the gyroscopic and non-gyroscopic two degree-of-freedom conservative systems

    Science.gov (United States)

    Yang, Xiao-Dong; An, Hua-Zhen; Qian, Ying-Jing; Zhang, Wei; Melnik, Roderick V. N.

    2016-12-01

    The synchronous in-unison motions in vibrational mechanics and the non-synchronous out-of-unison motions are the most frequently found periodic motions in every fields of science and everywhere in the universe. In contrast to the in-unison normal modes, the out-of-unison complex modes feature a π/2 phase difference. By the complex mode analysis we classify the out-of-unison planar motion into two types, gyroscopic motions and elliptic motions. It is found that the gyroscopic and elliptic motions have different characteristics for a two degree-of-freedom (2DOF) system. The gyroscopic motion involves two distinct frequencies with, respectively, two corresponding complex modes. However, the elliptic motion the nonlinear non-gyroscopic 2DOF system with repeated frequencies involves only single frequency with corresponding two complex modes. The study of the differences and similarities of the gyroscopic and elliptic modes sheds new light on the in-depth mechanism of the planar motions in the universe and the man-made engineering systems.

  8. Thermal and Quantum Mechanical Noise of a Superfluid Gyroscope

    Science.gov (United States)

    Chui, Talso; Penanen, Konstantin

    2004-01-01

    A potential application of a superfluid gyroscope is for real-time measurements of the small variations in the rotational speed of the Earth, the Moon, and Mars. Such rotational jitter, if not measured and corrected for, will be a limiting factor on the resolution potential of a GPS system. This limitation will prevent many automation concepts in navigation, construction, and biomedical examination from being realized. We present the calculation of thermal and quantum-mechanical phase noise across the Josephson junction of a superfluid gyroscope. This allows us to derive the fundamental limits on the performance of a superfluid gyroscope. We show that the fundamental limit on real-time GPS due to rotational jitter can be reduced to well below 1 millimeter/day. Other limitations and their potential mitigation will also be discussed.

  9. Microfibrous metallic cloth for acoustic isolation of a MEMS gyroscope

    Science.gov (United States)

    Dean, Robert; Burch, Nesha; Black, Meagan; Beal, Aubrey; Flowers, George

    2011-04-01

    The response of a MEMS device that is exposed to a harsh environment may range from an increased noise floor to a completely erroneous output to temporary or even permanent device failure. One such harsh environment is high power acoustic energy possessing high frequency components. This type of environment sometimes occurs in small aerospace vehicles. In this type of operating environment, high frequency acoustic energy can be transferred to a MEMS gyroscope die through the device packaging. If the acoustic noise possesses a sufficiently strong component at the resonant frequency of the gyroscope, it will overexcite the motion of the proof mass, resulting in the deleterious effect of corrupted angular rate measurement. Therefore if the device or system packaging can be improved to sufficiently isolate the gyroscope die from environmental acoustic energy, the sensor may find new applications in this type of harsh environment. This research effort explored the use of microfibrous metallic cloth for isolating the gyroscope die from environmental acoustic excitation. Microfibrous cloth is a composite of fused, intermingled metal fibers and has a variety of typical uses involving chemical processing applications and filtering. Specifically, this research consisted of experimental evaluations of multiple layers of packed microfibrous cloth composed of sintered nickel material. The packed cloth was used to provide acoustic isolation for a test MEMS gyroscope, the Analog Devices ADXRS300. The results of this investigation revealed that the intermingling of the various fibers of the metallic cloth provided a significant contact area between the fiber strands and voids, which enhanced the acoustic damping of the material. As a result, the nickel cloth was discovered to be an effective acoustic isolation material for this particular MEMS gyroscope.

  10. Studying rotational dynamics with a smartphone—accelerometer versus gyroscope

    Science.gov (United States)

    Braskén, Mats; Pörn, Ray

    2017-07-01

    The wide-spread availability of smartphones makes them a valuable addition to the measurement equipment of both the physics classroom and the instructional physics laboratory, encouraging an active interaction between measurements and modeling activities. Two useful sensors, available in most modern smartphones and tablets, are the 3-axis acceleration sensor and the 3-axis gyroscope. We explore the strengths and weaknesses of each type of sensor and use them to study the rotational dynamics of objects rotating about a fixed axis. Care has to be taken when interpreting acceleration sensor data, and in some cases the gyroscope will allow for rotational measurements not easily replicated using the acceleration sensor.

  11. Construction of Lyapunov Function for Dissipative Gyroscopic System

    International Nuclear Information System (INIS)

    Xu Wei; Ao Ping; Yuan Bo

    2011-01-01

    We introduce a force decomposition to construct a potential function in deterministic dynamics described by ordinary differential equations in the context of dissipative gyroscopic systems. Such a potential function serves as the corresponding Lyapunov function for the dynamics, hence it gives both quantitative and qualitative descriptions for stability of motion. As an example we apply our force decomposition to a four-dimensional dissipative gyroscopic system. We explicitly obtain the potential function for all parameter regimes in the linear limit, including those regimes where the Lyapunov function was previously believed not to exist. (general)

  12. Isolated resonator gyroscope with a drive and sense plate

    Science.gov (United States)

    Challoner, A. Dorian (Inventor); Shcheglov, Kirill V. (Inventor)

    2006-01-01

    The present invention discloses a resonator gyroscope comprising a vibrationally isolated resonator including a proof mass, a counterbalancing plate having an extensive planar region, and one or more flexures interconnecting the proof mass and counterbalancing plate. A baseplate is affixed to the resonator by the one or more flexures and sense and drive electrodes are affixed to the baseplate proximate to the extensive planar region of the counterbalancing plate for exciting the resonator and sensing movement of the gyroscope. The isolated resonator transfers substantially no net momentum to the baseplate when the resonator is excited.

  13. Coupled electromechanical model of an imperfect piezoelectric vibrating cylinder gyroscope

    CSIR Research Space (South Africa)

    Loveday, PW

    1996-01-01

    Full Text Available which is closed at one end with discrete piezoceramic actuation and sensing elements bonded close to the open end. The operation of the gyroscope and the effect of imperfections are briefly described. The model allows direct comparison with experimental...

  14. General problems of dynamics and control of vibratory gyroscopes

    CSIR Research Space (South Africa)

    Shatalov, MY

    2008-05-01

    Full Text Available A general model of operation of vibratory gyroscopes, which is applicable to a broad class of instruments, including cylindrical, disc and micro-machined gyros, is formulated on the basis of analysis of dynamics and control of a hemispherical...

  15. FPGA platform for MEMS Disc Resonance Gyroscope (DRG) control

    Science.gov (United States)

    Keymeulen, Didier; Peay, Chris; Foor, David; Trung, Tran; Bakhshi, Alireza; Withington, Phil; Yee, Karl; Terrile, Rich

    2008-04-01

    Inertial navigation systems based upon optical gyroscopes tend to be expensive, large, power consumptive, and are not long lived. Micro-Electromechanical Systems (MEMS) based gyros do not have these shortcomings; however, until recently, the performance of MEMS based gyros had been below navigation grade. Boeing and JPL have been cooperating since 1997 to develop high performance MEMS gyroscopes for miniature, low power space Inertial Reference Unit applications. The efforts resulted in demonstration of a Post Resonator Gyroscope (PRG). This experience led to the more compact Disc Resonator Gyroscope (DRG) for further reduced size and power with potentially increased performance. Currently, the mass, volume and power of the DRG are dominated by the size of the electronics. This paper will detail the FPGA based digital electronics architecture and its implementation for the DRG which will allow reduction of size and power and will increase performance through a reduction in electronics noise. Using the digital control based on FPGA, we can program and modify in real-time the control loop to adapt to the specificity of each particular gyro and the change of the mechanical characteristic of the gyro during its life time.

  16. Understanding Organizational Culture and Communication through a Gyroscope Metaphor

    Science.gov (United States)

    Bisel, Ryan S.; Messersmith, Amber S.; Keyton, Joann

    2010-01-01

    To fill a critical void in organizational culture pedagogy, the authors present an instructional system that employs the metaphor of a gyroscope to help students understand implicit assumptions in culture research. Working from Martin's nexus approach to organizational culture and Fairhurst and Putnam's tripartite theory of organizational…

  17. Fibre Optic Gyroscope Developments Using Integrated Optic Components

    Science.gov (United States)

    Minford, W. J.; DePaula, R. M.

    1988-09-01

    The sensing of rotation using counterpropagating optical beams in a fiber loop (the SAGNAC effect) has gone through extensive developments and demonstrations since first proved feasible by Vali and Shorthilll in 1976. The interferometric fiber gyroscope minimum configuration2 which uses a common input-output port and single-mode filter was developed to provide the extreme high stability necessary to reach the sensitivities at low rotation rates attainable with current state-of-the-art detectors. The simplicity and performance of this configuration has led to its acceptance and wide-spread use. In order to increase the mechanical stability of this system, all single-mode fiber components are employed and a further advancement to integrated optics has enabled most of the optical functions to be placed on a single mass-producible substrate. Recent improvements in the components (eg polarization maintaining fiber and low coherence sources) have further enhanced the performance of the minimum configuration gyro. This presentation focused on the impact of LiNbO3 integrated optic components on gyroscope developments. The use of Ti-indiffused LiNbO3 waveguide optical circuits in interferometric fiber optic gyroscopes has taken two directions: to utilize only the phase modulator, or to combine many of the minimum configuration optical functions on the electro-optic substrate. The high-bandwidth phase modulator is the driving force for using LiNbO3 waveguide devices. This device allows both biasing the gyro for maximum sensitivity and closing the loop via frequency shifting, for example, thus increasing the dynamic range of the gyro and the linearity of the scale factor. Efforts to implement most of the minimum configuration optical functions onto a single LiNbO3 substrate have been led by Thomson CSF.3 They have demonstrated an interferometric gyroscope with excellent performance using a LiNbO3 optical circuit containing a Y-splitter, phase modulator, and surface

  18. High resolution capacitance detection circuit for rotor micro-gyroscope

    Directory of Open Access Journals (Sweden)

    Ming-Yuan Ren

    2014-03-01

    Full Text Available Conventional methods for rotor position detection of micro-gyroscopes include common exciting electrodes (single frequency and common sensing electrodes (frequency multiplex, but they have encountered some problems. So we present a high resolution and low noise pick-off circuit for micro-gyroscopes which utilizes the time multiplex method. The detecting circuit adopts a continuous-time current sensing circuit for capacitance measurement, and its noise analysis of the charge amplifier is introduced. The equivalent output noise power spectral density of phase-sensitive demodulation is 120 nV/Hz1/2. Tests revealed that the whole circuitry has a relative capacitance resolution of 1 × 10−8.

  19. A Fully Symmetric and Completely Decoupled MEMS-SOI Gyroscope

    Directory of Open Access Journals (Sweden)

    Abdelhameed SHARAF

    2011-04-01

    Full Text Available This paper introduces a novel MEMS gyroscope that is capable of exciting the drive mode differentially. The structure also decouples the drive and sense modes via an intermediate mass and decoupling beams. Both drive and sense modes are fully differential enabling control over the zero-rate-output for the former and maximizing output sensitivity using a bridge circuit for the latter. Further, the structure is fully symmetric about the x- and y- axes which results in minimizing the temperature sensitivity problem. Complete analytical analysis based on the equations of motion was performed and verified using two commercially available finite element software packages. Results from both methods are in good agreement. The analysis of the sensor shows an electrical sensitivity of 1.14 (mV/(º/s. The gyroscope was fabricated using single mask and deep reactive ion etching. The measurement of the resonance frequency performed showing a good agreement with the analytical and numerical analysis.

  20. Collision avoidance for multiple Lagrangian dynamical systems with gyroscopic forces

    Directory of Open Access Journals (Sweden)

    Lorenzo Sabattini

    2017-01-01

    Full Text Available This article introduces a novel methodology for dealing with collision avoidance for groups of mobile robots. In particular, full dynamics are considered, since each robot is modeled as a Lagrangian dynamical system moving in a three-dimensional environment. Gyroscopic forces are utilized for defining the collision avoidance control strategy: This kind of forces leads to avoiding collisions, without interfering with the convergence properties of the multi-robot system’s desired control law. Collision avoidance introduces, in fact, a perturbation on the nominal behavior of the system: We define a method for choosing the direction of the gyroscopic force in an optimal manner, in such a way that perturbation is minimized. Collision avoidance and convergence properties are analytically demonstrated, and simulation results are provided for validation purpose.

  1. Servo Platform Circuit Design of Pendulous Gyroscope Based on DSP

    Science.gov (United States)

    Tan, Lilong; Wang, Pengcheng; Zhong, Qiyuan; Zhang, Cui; Liu, Yunfei

    2018-03-01

    In order to solve the problem when a certain type of pendulous gyroscope in the initial installation deviation more than 40 degrees, that the servo platform can not be up to the speed of the gyroscope in the rough north seeking phase. This paper takes the digital signal processor TMS320F28027 as the core, uses incremental digital PID algorithm, carries out the circuit design of the servo platform. Firstly, the hardware circuit is divided into three parts: DSP minimum system, motor driving circuit and signal processing circuit, then the mathematical model of incremental digital PID algorithm is established, based on the model, writes the PID control program in CCS3.3, finally, the servo motor tracking control experiment is carried out, it shows that the design can significantly improve the tracking ability of the servo platform, and the design has good engineering practice.

  2. Characterization and Modeling of a Control Moment Gyroscope

    Science.gov (United States)

    2015-03-26

    pre- conditioner for the input state before passing into the inner loop, as shown in Figure 30. In Figure 30, m is the motor angle and x is the state...Characterization and Modeling of a Control Moment Gyroscope THESIS 2d Lt, Dylan Penn, B.S. AFIT-ENY-MS-15-M-235 DEPARTMENT OF THE AIR FORCE AIR ...UNIVERSITY AIR FORCE INSTITUTE OF TECHNOLOGY Wright-Patterson Air Force Base, Ohio DISTRIBUTION STATEMENT A APPROVED FOR PUBLIC RELEASE; DISTRIBUTION

  3. OPTIMIZATION OF HEMISPHERICAL RESONATOR GYROSCOPE STANDING WAVE PARAMETERS

    Directory of Open Access Journals (Sweden)

    Olga Sergeevna Khalyutina

    2017-01-01

    Full Text Available Traditionally, the problem of autonomous navigation is solved by dead reckoning navigation flight parameters (NFP of the aircraft (AC. With increasing requirements to accuracy of definition NFP improved the sensors of the prima- ry navigation information: gyroscopes and accelerometers. the gyroscopes of a new type, the so-called solid-state wave gyroscopes (SSVG are currently developed and put into practice. The work deals with the problem of increasing the accu- racy of measurements of angular velocity of the hemispherical resonator gyroscope (HRG. The reduction in the accuracy characteristics of HRG is caused by the presence of defects in the distribution of mass in the volume of its design. The syn- thesis of control system for optimal damping of the distortion parameters of the standing wave due to the influence of the mass defect resonator is adapted. The research challenge was: to examine and analytically offset the impact of the standing wave (amplitude and frequency parameters defect. Research was performed by mathematical modeling in the environment of SolidWorks Simulation for the case when the characteristics of the sensitive element of the HRG met the technological drawings of a particular type of resonator. The method of the inverse dynamics was chosen for synthesis. The research re- sults are presented in graphs the amplitude-frequency characteristics (AFC of the resonator output signal. Simulation was performed for the cases: the perfect distribution of weight; the presence of the mass defect; the presence of the mass defects are shown using the synthesized control action. Evaluating the effectiveness of the proposed control algorithm is deter- mined by the results of the resonator output signal simulation provided the perfect constructive and its performance in the presence of a mass defect in it. It is assumed that the excitation signals are standing waves in the two cases are identical in both amplitude and frequency. In this

  4. The Gyroscope Sensor Test by Using Arduino Platform

    Directory of Open Access Journals (Sweden)

    Yi-Jen Mon

    2015-06-01

    Full Text Available Abstract The gyroscope has ability to get accurate data of motions for space of three dimensions such as axes of x y and z. Its applications are covered very widely such as in mobile phone consumer electronics etc. due to the robust sense abilities of direction and motion. In this paper it is used to get data from motion and these data are shown in window and LCD screen. The experiment results show that it has good performance.

  5. Indefinite damping in mechanical systems and gyroscopic stabilization

    DEFF Research Database (Denmark)

    Kliem, Wolfhard; Pommer, Christian

    2009-01-01

    This paper deals with gyroscopic stabilization of the unstable system Mx + D(x) over dot + K-x = 0, with positive definite mass and stiffness matrices M and K, respectively, and an indefinite damping matrix D. The main question if for which skew-symmetric matrices G the system Mx (D+ G)(x) over dot...... + K-x = 0 can become stable? After investigating special cases we find an appropriat solution of the Lyapunov matrix equation for the general case. Examples show the deviation of the stability limit found by the Lyapunov method from the exact value....

  6. On dynamics and control of vibratory gyroscopes with special spherical symmetry

    CSIR Research Space (South Africa)

    Shatalov, M

    2006-05-01

    Full Text Available It was shown in 1985 by Acad. V. Zhuravlev that the angular rate of a pure vibrating mode excited in a vibratory gyroscope with spherical symmetry is proportional to an inertial angular rate of the gyroscope. The effect is three dimensional...

  7. Gravity Probe B: Examining Einstein's Spacetime with Gyroscopes. An Educator's Guide with Activities in Space Science.

    Science.gov (United States)

    Range, Shannon K'doah; Mullins, Jennifer

    This teaching guide introduces a relativity gyroscope experiment aiming to test two unverified predictions of Albert Einstein's general theory of relativity. An introduction to the theory includes the following sections: (1) "Spacetime, Curved Spacetime, and Frame-Dragging"; (2) "'Seeing' Spacetime with Gyroscopes"; (3)…

  8. Stability analysis of the Gyroscopic Power Take-Off wave energy point absorber

    DEFF Research Database (Denmark)

    Nielsen, Søren R. K.; Zhang, Zili; Kramer, Morten Mejlhede

    2015-01-01

    The Gyroscopic Power Take-Off (GyroPTO) wave energy point absorber consists of a float rigidly connected to a lever. The operational principle is somewhat similar to that of the so-called gyroscopic hand wrist exercisers, where the rotation of the float is brought forward by the rotational particle...

  9. Design and fabrication of a biomimetic gyroscope inspired by the fly's haltere

    NARCIS (Netherlands)

    Droogendijk, H.; Brookhuis, Robert Anton; de Boer, Meint J.; Sanders, Remco G.P.; Krijnen, Gijsbertus J.M.

    2012-01-01

    We report on the design and fabrication of a MEMS-based gyroscopic system inspired by the fly's haltere system. Two types of so-called biomimetic gyroscopes have been designed, fabricated and their drive mode has been characterized. First measurements indicate excitable gyropscopes with natural

  10. Design and fabrication of a biomimetic gyroscope inspired by the fly’s haltere

    NARCIS (Netherlands)

    Droogendijk, H.; Brookhuis, Robert Anton; de Boer, Meint J.; Sanders, Remco G.P.; Krijnen, Gijsbertus J.M.

    2013-01-01

    We report on the design and fabrication of a MEMS-based gyroscopic system inspired by the fly’s haltere system. Two types of so-called biomimetic gyroscopes have been designed, fabricated and partially characterized. First measurements indicate excitable gyropscopes with natural frequencies in the

  11. Optimal Design of a Center Support Quadruple Mass Gyroscope (CSQMG

    Directory of Open Access Journals (Sweden)

    Tian Zhang

    2016-04-01

    Full Text Available This paper reports a more complete description of the design process of the Center Support Quadruple Mass Gyroscope (CSQMG, a gyro expected to provide breakthrough performance for flat structures. The operation of the CSQMG is based on four lumped masses in a circumferential symmetric distribution, oscillating in anti-phase motion, and providing differential signal extraction. With its 4-fold symmetrical axes pattern, the CSQMG achieves a similar operation mode to Hemispherical Resonant Gyroscopes (HRGs. Compared to the conventional flat design, four Y-shaped coupling beams are used in this new pattern in order to adjust mode distribution and enhance the synchronization mechanism of operation modes. For the purpose of obtaining the optimal design of the CSQMG, a kind of applicative optimization flow is developed with a comprehensive derivation of the operation mode coordination, the pseudo mode inhibition, and the lumped mass twisting motion elimination. The experimental characterization of the CSQMG was performed at room temperature, and the center operation frequency is 6.8 kHz after tuning. Experiments show an Allan variance stability 0.12°/h (@100 s and a white noise level about 0.72°/h/√Hz, which means that the CSQMG possesses great potential to achieve navigation grade performance.

  12. Track Detection in Railway Sidings Based on MEMS Gyroscope Sensors

    Science.gov (United States)

    Broquetas, Antoni; Comerón, Adolf; Gelonch, Antoni; Fuertes, Josep M.; Castro, J. Antonio; Felip, Damià; López, Miguel A.; Pulido, José A.

    2012-01-01

    The paper presents a two-step technique for real-time track detection in single-track railway sidings using low-cost MEMS gyroscopes. The objective is to reliably know the path the train has taken in a switch, diverted or main road, immediately after the train head leaves the switch. The signal delivered by the gyroscope is first processed by an adaptive low-pass filter that rejects noise and converts the temporal turn rate data in degree/second units into spatial turn rate data in degree/meter. The conversion is based on the travelled distance taken from odometer data. The filter is implemented to achieve a speed-dependent cut-off frequency to maximize the signal-to-noise ratio. Although direct comparison of the filtered turn rate signal with a predetermined threshold is possible, the paper shows that better detection performance can be achieved by processing the turn rate signal with a filter matched to the rail switch curvature parameters. Implementation aspects of the track detector have been optimized for real-time operation. The detector has been tested with both simulated data and real data acquired in railway campaigns. PMID:23443376

  13. Optimization of the geometrical stability in square ring laser gyroscopes

    International Nuclear Information System (INIS)

    Santagata, R; Beghi, A; Cuccato, D; Belfi, J; Beverini, N; Virgilio, A Di; Ortolan, A; Porzio, A; Solimeno, S

    2015-01-01

    Ultra-sensitive ring laser gyroscopes are regarded as potential detectors of the general relativistic frame-dragging effect due to the rotation of the Earth. Our project for this goal is called GINGER (gyroscopes in general relativity), and consists of a ground-based triaxial array of ring lasers aimed at measuring the rotation rate of the Earth with an accuracy of 10 −14 rad s −1 . Such an ambitious goal is now within reach, as large-area ring lasers are very close to the required sensitivity and stability. However, demanding constraints on the geometrical stability of the optical path of the laser inside the ring cavity are required. Thus, we have begun a detailed study of the geometry of an optical cavity in order to find a control strategy for its geometry that could meet the specifications of the GINGER project. As the cavity perimeter has a stationary point for the square configuration, we identify a set of transformations on the mirror positions that allows us to adjust the laser beam steering to the shape of a square. We show that the geometrical stability of a square cavity strongly increases by implementing a suitable system to measure the mirror distances, and that the geometry stabilization can be achieved by measuring the absolute lengths of the two diagonals and the perimeter of the ring. (paper)

  14. Topological dynamics of gyroscopic and Floquet lattices from Newton's laws

    Science.gov (United States)

    Lee, Ching Hua; Li, Guangjie; Jin, Guliuxin; Liu, Yuhan; Zhang, Xiao

    2018-02-01

    Despite intense interest in realizing topological phases across a variety of electronic, photonic, and mechanical platforms, the detailed microscopic origin of topological behavior often remains elusive. To bridge this conceptual gap, we show how hallmarks of topological modes—boundary localization and chirality—emerge from Newton's laws in mechanical topological systems. We first construct a gyroscopic lattice with analytically solvable edge modes, and show how the Lorentz and spring restoring forces conspire to support very robust "dangling bond" boundary modes. The chirality and locality of these modes intuitively emerges from microscopic balancing of restoring forces and cyclotron tendencies. Next, we introduce the highlight of this work, an experimentally realistic mechanical nonequilibrium (Floquet) Chern lattice driven by ac electromagnets. Through appropriate synchronization of the ac driving protocol, the Floquet lattice is "pushed around" by a rotating potential analogous to an object washed ashore by water waves. Besides hosting "dangling bond" chiral modes analogous to the gyroscopic boundary modes, our Floquet Chern lattice also supports peculiar half-period chiral modes with no static analog, i.e., analogs of anomalous Floquet Chern insulators edge modes. With key parameters controlled electronically, our setup has the advantage of being dynamically tunable for applications involving arbitrary Floquet modulations. The physical intuition gleaned from our two prototypical topological systems is applicable not just to arbitrarily complicated mechanical systems, but also photonic and electrical topological setups.

  15. Three-Axis Attitude Estimation Using Rate-Integrating Gyroscopes

    Science.gov (United States)

    Crassidis, John L.; Markley, F. Landis

    2016-01-01

    Traditionally, attitude estimation has been performed using a combination of external attitude sensors and internal three-axis gyroscopes. There are many studies of three-axis attitude estimation using gyros that read angular rates. Rate-integrating gyros measure integrated rates or angular displacements, but three-axis attitude estimation using these types of gyros has not been as fully investigated. This paper derives a Kalman filtering framework for attitude estimation using attitude sensors coupled with rate- integrating gyroscopes. In order to account for correlations introduced by using these gyros, the state vector must be augmented, compared with filters using traditional gyros that read angular rates. Two filters are derived in this paper. The first uses an augmented state-vector form that estimates attitude, gyro biases, and gyro angular displacements. The second ignores correlations, leading to a filter that estimates attitude and gyro biases only. Simulation comparisons are shown for both filters. The work presented in this paper focuses only on attitude estimation using rate-integrating gyros, but it can easily be extended to other applications such as inertial navigation, which estimates attitude and position.

  16. The Gravity-Probe-B relativity gyroscope experiment - Development of the prototype flight instrument

    Science.gov (United States)

    Turneaure, J. P.; Everitt, C. W. F.; Parkinson, B. W.; Bardas, D.; Breakwell, J. V.

    1989-01-01

    The Gravity-Probe-B relativity gyroscope experiment (GP-B) will measure the geodetic and frame-dragging precession rates of gyroscopes in a 650 km high polar orbit about the earth. The goal is to measure these two effects, which are predicted by Einstein's General Theory of Relativity, to 0.01 percent (geodetic) and 1 percent (frame-dragging). This paper presents the development progress for full-size prototype flight hardware including the gyroscopes, gyro readout and magnetic shielding system, and an integrated ground test instrument.

  17. Modeling of Thermal Phase Noise in a Solid Core Photonic Crystal Fiber-Optic Gyroscope.

    Science.gov (United States)

    Song, Ningfang; Ma, Kun; Jin, Jing; Teng, Fei; Cai, Wei

    2017-10-26

    A theoretical model of the thermal phase noise in a square-wave modulated solid core photonic crystal fiber-optic gyroscope has been established, and then verified by measurements. The results demonstrate a good agreement between theory and experiment. The contribution of the thermal phase noise to the random walk coefficient of the gyroscope is derived. A fiber coil with 2.8 km length is used in the experimental solid core photonic crystal fiber-optic gyroscope, showing a random walk coefficient of 9.25 × 10 -5 deg/√h.

  18. On the Interpretation of 3D Gyroscope Measurements

    Directory of Open Access Journals (Sweden)

    Sara Stančin

    2018-01-01

    Full Text Available We demonstrate that the common interpretation of angular velocities measured by a 3D gyroscope as being sequential Euler rotations introduces a systematic error in the sensor orientation calculated during motion tracking. For small rotation angles, this systematic error is relatively small and can be mistakenly attributed to different sources of sensor inaccuracies, including output bias drift, inaccurate sensitivities, and alignments of the sensor sensitivity axes as well as measurement noise. However, even for such small angles, due to accumulation over time, the erroneous rotation interpretation can have a significant negative impact on the accuracy of the computed angular orientation. We confirm our findings using real-case measurements in which the described systematic error just worsens the deleterious effects typically attributed to an inaccurate sensor and random measurement noise. We demonstrate that, in general, significant improvement in the angular orientation accuracy can be achieved if the measured angular velocities are correctly interpreted as simultaneous and not as sequential rotations.

  19. Spherical gyroscopic moment stabilizer for attitude control of microsatellites

    Science.gov (United States)

    Keshtkar, Sajjad; Moreno, Jaime A.; Kojima, Hirohisa; Uchiyama, Kenji; Nohmi, Masahiro; Takaya, Keisuke

    2018-02-01

    This paper presents a new and improved concept of recently proposed two-degrees of freedom spherical stabilizer for triaxial orientation of microsatellites. The analytical analysis of the advantages of the proposed mechanism over the existing inertial attitude control devices are introduced. The extended equations of motion of the stabilizing satellite including the spherical gyroscope, for control law design and numerical simulations, are studied in detail. A new control algorithm based on continuous high-order sliding mode algorithms, for managing the torque produced by the stabilizer and therefore the attitude control of the satellite in the presence of perturbations/uncertainties, is presented. Some numerical simulations are carried out to prove the performance of the proposed mechanism and control laws.

  20. Realization of a topological phase transition in a gyroscopic lattice

    Science.gov (United States)

    Mitchell, Noah P.; Nash, Lisa M.; Irvine, William T. M.

    2018-03-01

    Topological metamaterials exhibit unusual behaviors at their boundaries, such as unidirectional chiral waves, that are protected by a topological feature of their band structures. The ability to tune such a material through a topological phase transition in real time could enable the use of protected waves for information storage and readout. Here we dynamically tune through a topological phase transition by breaking inversion symmetry in a metamaterial composed of interacting gyroscopes. Through the transition, we track the divergence of the edge modes' localization length and the change in Chern number characterizing the topology of the material's band structure. This Rapid Communication provides a new axis with which to tune the response of mechanical topological metamaterials.

  1. Design and Simulation of A Novel Piezoelectric AlN-Si Cantilever Gyroscope

    Directory of Open Access Journals (Sweden)

    Jian Yang

    2018-02-01

    Full Text Available A novel design of piezoelectric aluminum nitride (AlN-Si composite cantilever gyroscope is proposed in this paper. The cantilever is stimulated to oscillate in plane by two inverse voltages which are applied on the two paralleled drive electrodes, respectively. The whole working principles are deduced, which based on the piezoelectric equation and elastic vibration equation. In this work, a cantilever gyroscope has been simulated and optimized by COMSOL Multiphysics 5.2a. The drive mode frequency is 87.422 kHz, and the sense mode frequency is 87.414 kHz. The theoretical sensitivity of this gyroscope is 0.145 pm/◦/s. This gyroscope has a small size and simple structure. It will be a better choice for the consumer electronics.

  2. Analysis of the gyroscopic stabilization of a system of rigid bodies

    DEFF Research Database (Denmark)

    Kliem, Wolfhard; Seyranian, Alexander P.

    1997-01-01

    We study the gyroscopic stability of a three-body system. A new method of finding stability regions, based on mechanism and criteria for gyroscopic stabilization, is presented. Of particular interest in this connection is the theory of interaction of eigenvalues. This leads to a complete 3......-dimensional analysis, which shows the regions of stability, divergence, and flutter of a simple model of a rotating spaceship....

  3. Design, Fabrication, and Modeling of a Novel Dual-Axis Control Input PZT Gyroscope.

    Science.gov (United States)

    Chang, Cheng-Yang; Chen, Tsung-Lin

    2017-10-31

    Conventional gyroscopes are equipped with a single-axis control input, limiting their performance. Although researchers have proposed control algorithms with dual-axis control inputs to improve gyroscope performance, most have verified the control algorithms through numerical simulations because they lacked practical devices with dual-axis control inputs. The aim of this study was to design a piezoelectric gyroscope equipped with a dual-axis control input so that researchers may experimentally verify those control algorithms in future. Designing a piezoelectric gyroscope with a dual-axis control input is more difficult than designing a conventional gyroscope because the control input must be effective over a broad frequency range to compensate for imperfections, and the multiple mode shapes in flexural deformations complicate the relation between flexural deformation and the proof mass position. This study solved these problems by using a lead zirconate titanate (PZT) material, introducing additional electrodes for shielding, developing an optimal electrode pattern, and performing calibrations of undesired couplings. The results indicated that the fabricated device could be operated at 5.5±1 kHz to perform dual-axis actuations and position measurements. The calibration of the fabricated device was completed by system identifications of a new dynamic model including gyroscopic motions, electromechanical coupling, mechanical coupling, electrostatic coupling, and capacitive output impedance. Finally, without the assistance of control algorithms, the "open loop sensitivity" of the fabricated gyroscope was 1.82 μV/deg/s with a nonlinearity of 9.5% full-scale output. This sensitivity is comparable with those of other PZT gyroscopes with single-axis control inputs.

  4. Design, Fabrication, and Modeling of a Novel Dual-Axis Control Input PZT Gyroscope

    Directory of Open Access Journals (Sweden)

    Cheng-Yang Chang

    2017-10-01

    Full Text Available Conventional gyroscopes are equipped with a single-axis control input, limiting their performance. Although researchers have proposed control algorithms with dual-axis control inputs to improve gyroscope performance, most have verified the control algorithms through numerical simulations because they lacked practical devices with dual-axis control inputs. The aim of this study was to design a piezoelectric gyroscope equipped with a dual-axis control input so that researchers may experimentally verify those control algorithms in future. Designing a piezoelectric gyroscope with a dual-axis control input is more difficult than designing a conventional gyroscope because the control input must be effective over a broad frequency range to compensate for imperfections, and the multiple mode shapes in flexural deformations complicate the relation between flexural deformation and the proof mass position. This study solved these problems by using a lead zirconate titanate (PZT material, introducing additional electrodes for shielding, developing an optimal electrode pattern, and performing calibrations of undesired couplings. The results indicated that the fabricated device could be operated at 5.5±1 kHz to perform dual-axis actuations and position measurements. The calibration of the fabricated device was completed by system identifications of a new dynamic model including gyroscopic motions, electromechanical coupling, mechanical coupling, electrostatic coupling, and capacitive output impedance. Finally, without the assistance of control algorithms, the “open loop sensitivity” of the fabricated gyroscope was 1.82 μV/deg/s with a nonlinearity of 9.5% full-scale output. This sensitivity is comparable with those of other PZT gyroscopes with single-axis control inputs.

  5. Design and Implementation of a Dual-Mass MEMS Gyroscope with High Shock Resistance.

    Science.gov (United States)

    Gao, Yang; Huang, Libin; Ding, Xukai; Li, Hongsheng

    2018-03-30

    This paper presents the design and implementation of a dual-mass MEMS gyroscope with high shock resistance by improving the in-phase frequency of the gyroscope and by using a two-stage elastic stopper mechanism and proposes a Simulink shock model of the gyroscope equipped with the two-stage stopper mechanism, which is a very efficient method to evaluate the shock resistance of the gyroscope. The structural design takes into account both the mechanical sensitivity and the shock resistance. The design of the primary structure and the analysis of the stopper mechanism are first introduced. Based on the expression of the restoring force of the stopper beam, the analytical shock response model of the gyroscope is obtained. By this model, the shock response of the gyroscope is theoretically analyzed, and the appropriate structural parameters are obtained. Then, the correctness of the model is verified by finite element (FE) analysis, where the contact collision analysis is introduced in detail. The simulation results show that the application of the two-stage elastic stopper mechanism can effectively improve the shock resistance by more than 1900 g and 1500 g in the x - and y -directions, respectively. Finally, experimental verifications are carried out by using a machete hammer on the micro-gyroscope prototype fabricated by the deep dry silicon on glass (DDSOG) technology. The results show that the shock resistance of the prototype along the x -, y - and z -axes all exceed 10,000 g. Moreover, the output of the gyroscope can return to normal in about 2 s.

  6. Dynamics of Molecular Gyroscopes Created by Strong Optical Fields

    Science.gov (United States)

    Mullin, Amy

    2015-03-01

    We explore the behavior of molecules in ultra-high angular momentum states prepared in an optical centrifuge and detected with transient IR absorption spectroscopy. In the optical centrifuge, the polarizable electron cloud of molecules interacts with the electric field of linearly polarized light that angularly accelerates over the time of the optical pulse. The centrifuge pulse is generated by combining oppositely chirped pulsed of light. Trapped molecules are driven into high angular momentum states that are spatially oriented with the optical field and have energies far above the average at 300 K. High resolution transient IR spectroscopy reveals the dynamics of collisional energy transfer for the super-rotors. Polarization-dependent studies show that the initial angular momentum orientation persists for many collisions, indicating that molecules in an optical centrifuge behave as quantum gyroscopes. Time-dependent population and energy profiles for individual J- states give information about the dynamics of super-rotors. Research support provided by NSF and the University of Maryland.

  7. Atrial Fibrillation Detection via Accelerometer and Gyroscope of a Smartphone.

    Science.gov (United States)

    Lahdenoja, Olli; Hurnanen, Tero; Iftikhar, Zuhair; Nieminen, Sami; Knuutila, Timo; Saraste, Antti; Kiviniemi, Tuomas; Vasankari, Tuija; Airaksinen, Juhani; Pankaala, Mikko; Koivisto, Tero

    2018-01-01

    We present a smartphone-only solution for the detection of atrial fibrillation (AFib), which utilizes the built-in accelerometer and gyroscope sensors [inertial measurement unit, (IMU)] in the detection. Depending on the patient's situation, it is possible to use the developed smartphone application either regularly or occasionally for making a measurement of the subject. The smartphone is placed on the chest of the patient who is adviced to lay down and perform a noninvasive recording, while no external sensors are needed. After that, the application determines whether the patient suffers from AFib or not. The presented method has high potential to detect paroxysmal ("silent") AFib from large masses. In this paper, we present the preprocessing, feature extraction, feature analysis, and classification results of the envisioned AFib detection system based on clinical data acquired with a standard mobile phone equipped with Google Android OS. Test data was gathered from 16 AFib patients (validated against ECG), as well as a control group of 23 healthy individuals with no diagnosed heart diseases. We obtained an accuracy of 97.4% in AFib versus healthy classification (a sensitivity of 93.8% and a specificity of 100%). Due to the wide availability of smart devices/sensors with embedded IMU, the proposed methods could potentially also scale to other domains such as embedded body-sensor networks.

  8. Online technique for detecting state of onboard fiber optic gyroscope

    International Nuclear Information System (INIS)

    Miao, Zhiyong; He, Kunpeng; Pang, Shuwan; Xu, Dingjie; Tian, Chunmiao

    2015-01-01

    Although angle random walk (ARW) of fiber optic gyroscope (FOG) has been well modeled and identified before being integrated into the high-accuracy attitude control system of satellite, aging and unexpected failures can affect the performance of FOG after launch, resulting in the variation of ARW coefficient. Therefore, the ARW coefficient can be regarded as an indicator of “state of health” for FOG diagnosis in some sense. The Allan variance method can be used to estimate ARW coefficient of FOG, however, it requires a large amount of data to be stored. Moreover, the procedure of drawing slope lines for estimation is painful. To overcome the barriers, a weighted state-space model that directly models the ARW to obtain a nonlinear state-space model was established for FOG. Then, a neural extended-Kalman filter algorithm was implemented to estimate and track the variation of ARW in real time. The results of experiment show that the proposed approach is valid to detect the state of FOG. Moreover, the proposed technique effectively avoids the storage of data

  9. A Micro Dynamically Tuned Gyroscope with Adjustable Static Capacitance

    Directory of Open Access Journals (Sweden)

    Lun Kong

    2013-02-01

    Full Text Available This paper presents a novel micro dynamically tuned gyroscope (MDTG with adjustable static capacitance. First, the principle of MDTG is theoretically analyzed. Next, some simulations under the optimized structure parameters are given as a reference for the mask design of the rotor wafer and electrode plates. As two key components, the process flows of the rotor wafer and electrode plates are described in detail. All the scanning electron microscopy (SEM photos show that the fabrication process is effective and optimized. Then, an assembly model is designed for the static capacitance adjustable MDTG, whose static capacitance can be changed by rotating the lower electrode plate support and substituting gasket rings of different thicknesses. Thus, the scale factor is easily changeable. Afterwards, the digitalized closed-loop measurement circuit is simulated. The discrete correction and decoupling modules are designed to make the closed-loop stable and cross-coupling effect small. The dual axis closed-loop system bandwidths can reach more than 60 Hz and the dual axis scale factors are completely symmetrical. All the simulation results demonstrate the proposed fabrication of the MDTG can meet the application requirements. Finally, the paper presents the test results of static and dynamic capacitance values which are consistent with the simulation values.

  10. Gyroscopic stimulation of the semicircular canals during sensory deprivation.

    Science.gov (United States)

    Newsom, B. D.; Brady, J. F.; Stumm, J. E.

    1971-01-01

    A static object revolving at a constant velocity is stationary with respect to that environment. When the object is rotated outside the plane of spin, a gyroscopic or cross-coupled acceleration is produced orthogonal to the two planes of rotation. In this situation, a man feels himself moving in a direction other than that which his visual or proprioceptive sensors perceive. The conflict in spatial orientation is the cross-coupled acceleration imposed on the semicircular canals. This perceptual conflict and the thresholds involved were studied by partial isolation of the physiological stimuli through sensory deprivation. Subjects weighted to neutral buoyancy were submerged in 94 F water in the dark. The subjects were then rotated while being revolved about a displaced axis. Thresholds for detection of angular acceleration were higher than those reported in the literature for detection of acceleration of a single plane. This discrepancy may be attributable to the length of time the stimuli are imposed to each of the canals and the cupular response periods.

  11. ATMOSPHERE PRESSURE EFFECT ON THE FIBER OPTIC GYROSCOPE OUTPUT SYGNAL

    Directory of Open Access Journals (Sweden)

    Ilya A. Sharkov

    2017-05-01

    Full Text Available The paper describes research results of the atmospheric pressure effect on the output signal of a fiber optic gyroscope (FOG. In the course of experiments, FOG was placed into a hermetic chamber. The atmosphere pressure was varying in the range from 0.8 to 1.5 atm. All the data, including the FOG output signal, temperature, and data from the pressure sensor installed inside the FOG, were synchronously registered with the computer software. The separation of scale factor change from zero offset in the experiment was carried out by setting the sensitive FOG axis at 0°, 90° and 270° relative to the East (the FOG was set perpendicular to the horizon. After the data processing it was concluded that the FOG signal error associated with the pressure affects mainly on the additive component. The pressure effect on the multiplicative component appeared to be negligible at rotational velocities used in the experiment (0 - 130 /h. At the same time, the FOG signal has a high linear correlation coefficient with the derivative of pressure over time (in some cases, more than 0.9. The experiment was repeated several times and the high degree of the drift repeatability was shown. That makes it possible to implement the compensation algorithm. Application of the simplest algorithmic compensation based on the polynomial of the first degree (ax + b enabled to reduce the root-mean-square (RMS and drift of the signal by 2-9 times.

  12. Free vibration of elastically supported thin cylinders including gyroscopic effects

    CSIR Research Space (South Africa)

    Loveday, PW

    1998-10-29

    Full Text Available [ The equations D[R[ 747723 JSV 106:2 "Issue# MS 1560 VIBRATION OF THIN CYLINDERS 442 required for this procedure\\ including the gyroscopic terms\\ are included in Appendix A[ The displacement functions can then be written as follows] W"x# C0 cosh a0xa C1 sinh a0... xa C2 cos g1xa C3 sin g1xa epx:a0C4 cos qxa C5 sin qxa 1 e px:a0C6 cos qxa C7 sin qxa 1 "6a# V"x# A0C0 cosh a0xa A0C1 sinh a0xa A2C2 cos g1xa A2C3 sin g1xa epx:a$"A4C4 A5C5# cos qxa "A4C5 A5C4# sin qxa % e px:a$"A4C6 A5C7# cos...

  13. Online technique for detecting state of onboard fiber optic gyroscope

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Zhiyong; He, Kunpeng, E-mail: pengkhe@126.com; Pang, Shuwan [Department of Automation, Harbin Engineering University, Harbin, Heilongjiang 150000 (China); Xu, Dingjie [School of Electrical Engineering and Automation, Harbin Institute of Technology, Harbin, Heilongjiang 150000 (China); Tian, Chunmiao [Department of Information and Communication Engineering, Harbin Engineering University, Harbin, Heilongjiang 150000 (China)

    2015-02-15

    Although angle random walk (ARW) of fiber optic gyroscope (FOG) has been well modeled and identified before being integrated into the high-accuracy attitude control system of satellite, aging and unexpected failures can affect the performance of FOG after launch, resulting in the variation of ARW coefficient. Therefore, the ARW coefficient can be regarded as an indicator of “state of health” for FOG diagnosis in some sense. The Allan variance method can be used to estimate ARW coefficient of FOG, however, it requires a large amount of data to be stored. Moreover, the procedure of drawing slope lines for estimation is painful. To overcome the barriers, a weighted state-space model that directly models the ARW to obtain a nonlinear state-space model was established for FOG. Then, a neural extended-Kalman filter algorithm was implemented to estimate and track the variation of ARW in real time. The results of experiment show that the proposed approach is valid to detect the state of FOG. Moreover, the proposed technique effectively avoids the storage of data.

  14. Super-large optical gyroscopes for applications in geodesy and seismology: state-of-the-art and development prospects

    International Nuclear Information System (INIS)

    Velikoseltsev, A A; Luk'yanov, D P; Vinogradov, V I; Shreiber, K U

    2014-01-01

    A brief survey of the history of the invention and development of super-large laser gyroscopes (SLLGs) is presented. The basic results achieved using SLLGs in geodesy, seismology, fundamental physics and other fields are summarised. The concept of SLLG design, specific features of construction and implementation are considered, as well as the prospects of applying the present-day optical technologies to laser gyroscope engineering. The possibilities of using fibre-optical gyroscopes in seismologic studies are analysed and the results of preliminary experimental studies are presented. (laser gyroscopes)

  15. Super-large optical gyroscopes for applications in geodesy and seismology: state-of-the-art and development prospects

    Energy Technology Data Exchange (ETDEWEB)

    Velikoseltsev, A A; Luk' yanov, D P [St. Petersburg Electrotechnical University ' ' LETI' ' , St. Petersburg (Russian Federation); Vinogradov, V I [OJSC Tambov factory Elektropribor (Russian Federation); Shreiber, K U [Forschungseinrichtung Satellitengeodaesie, Technosche Universitaet Muenchen, Geodaetisches Observatorium Wettzell, Sackenrieder str. 25, 93444 Bad Koetzting (Germany)

    2014-12-31

    A brief survey of the history of the invention and development of super-large laser gyroscopes (SLLGs) is presented. The basic results achieved using SLLGs in geodesy, seismology, fundamental physics and other fields are summarised. The concept of SLLG design, specific features of construction and implementation are considered, as well as the prospects of applying the present-day optical technologies to laser gyroscope engineering. The possibilities of using fibre-optical gyroscopes in seismologic studies are analysed and the results of preliminary experimental studies are presented. (laser gyroscopes)

  16. Application of the gyroscopic method in subterranean orientation. Comparison with conventional methods. Aplicacion del metodo gyroscopic en la orientacion subterranea. Comparacion con los metodos convencionales

    Energy Technology Data Exchange (ETDEWEB)

    Saez Garcia, E.; Fuente Martin, P.L. (HUNOSA, Madrid (Spain))

    1988-01-01

    This entry tries to revise the most used method for the direction transition what with exterior and interior using plumbs in connected with vertical shaft coalmines. A technical and economic cooperation was also realized between the indicated method and the gyroscope.

  17. MEMS 3-DoF gyroscope design, modeling and simulation through equivalent circuit lumped parameter model

    International Nuclear Information System (INIS)

    Mian, Muhammad Umer; Khir, M. H. Md.; Tang, T. B.; Dennis, John Ojur; Riaz, Kashif; Iqbal, Abid; Bazaz, Shafaat A.

    2015-01-01

    Pre-fabrication, behavioural and performance analysis with computer aided design (CAD) tools is a common and fabrication cost effective practice. In light of this we present a simulation methodology for a dual-mass oscillator based 3 Degree of Freedom (3-DoF) MEMS gyroscope. 3-DoF Gyroscope is modeled through lumped parameter models using equivalent circuit elements. These equivalent circuits consist of elementary components which are counterpart of their respective mechanical components, used to design and fabricate 3-DoF MEMS gyroscope. Complete designing of equivalent circuit model, mathematical modeling and simulation are being presented in this paper. Behaviors of the equivalent lumped models derived for the proposed device design are simulated in MEMSPRO T-SPICE software. Simulations are carried out with the design specifications following design rules of the MetalMUMPS fabrication process. Drive mass resonant frequencies simulated by this technique are 1.59 kHz and 2.05 kHz respectively, which are close to the resonant frequencies found by the analytical formulation of the gyroscope. The lumped equivalent circuit modeling technique proved to be a time efficient modeling technique for the analysis of complex MEMS devices like 3-DoF gyroscopes. The technique proves to be an alternative approach to the complex and time consuming couple field analysis Finite Element Analysis (FEA) previously used

  18. MEMS 3-DoF gyroscope design, modeling and simulation through equivalent circuit lumped parameter model

    Energy Technology Data Exchange (ETDEWEB)

    Mian, Muhammad Umer, E-mail: umermian@gmail.com; Khir, M. H. Md.; Tang, T. B. [Department of Electrical and Electronic Engineering, Universiti Teknologi PETRONAS, Tronoh, Perak (Malaysia); Dennis, John Ojur [Department of Fundamental & Applied Sciences, Universiti Teknologi PETRONAS, Tronoh, Perak (Malaysia); Riaz, Kashif; Iqbal, Abid [Faculty of Electronics Engineering, GIK Institute of Engineering Sciences and Technology, Topi, Khyber Pakhtunkhaw (Pakistan); Bazaz, Shafaat A. [Department of Computer Science, Center for Advance Studies in Engineering, Islamabad (Pakistan)

    2015-07-22

    Pre-fabrication, behavioural and performance analysis with computer aided design (CAD) tools is a common and fabrication cost effective practice. In light of this we present a simulation methodology for a dual-mass oscillator based 3 Degree of Freedom (3-DoF) MEMS gyroscope. 3-DoF Gyroscope is modeled through lumped parameter models using equivalent circuit elements. These equivalent circuits consist of elementary components which are counterpart of their respective mechanical components, used to design and fabricate 3-DoF MEMS gyroscope. Complete designing of equivalent circuit model, mathematical modeling and simulation are being presented in this paper. Behaviors of the equivalent lumped models derived for the proposed device design are simulated in MEMSPRO T-SPICE software. Simulations are carried out with the design specifications following design rules of the MetalMUMPS fabrication process. Drive mass resonant frequencies simulated by this technique are 1.59 kHz and 2.05 kHz respectively, which are close to the resonant frequencies found by the analytical formulation of the gyroscope. The lumped equivalent circuit modeling technique proved to be a time efficient modeling technique for the analysis of complex MEMS devices like 3-DoF gyroscopes. The technique proves to be an alternative approach to the complex and time consuming couple field analysis Finite Element Analysis (FEA) previously used.

  19. Towards a fully integrated optical gyroscope using whispering gallery modes resonators

    Science.gov (United States)

    Amrane, T.; Jager, J.-B.; Jager, T.; Calvo, V.; Léger, J.-M.

    2017-11-01

    Since the developments of lasers and the optical fibers in the 70s, the optical gyroscopes have been subject to an intensive research to improve both their resolution and stability performances. However the best optical gyroscopes currently on the market, the ring laser gyroscope and the interferometer fiber optic gyroscope are still macroscopic devices and cannot address specific applications where size and weight constraints are critical. One solution to overcome these limitations could be to use an integrated resonator as a sensitive part to build a fully Integrated Optical Resonant Gyroscope (IORG). To keep a high rotation sensitivity, which is usually degraded when downsizing this kind of optical sensors based on the Sagnac effect, the resonator has to exhibit a very high quality factor (Q): as detailed in equation (1) where the minimum rotation rate resolution for an IORG is given as a function of the resonator characteristics (Q and diameter D) and of the global system optical system characteristics (i.e. SNR and bandwidth B), the higher the Q×D product, the lower the resolution.

  20. The design of photoelectric signal processing system for a nuclear magnetic resonance gyroscope based on FPGA

    Science.gov (United States)

    Zhang, Xian; Zhou, Binquan; Li, Hong; Zhao, Xinghua; Mu, Weiwei; Wu, Wenfeng

    2017-10-01

    Navigation technology is crucial to the national defense and military, which can realize the measurement of orientation, positioning, attitude and speed for moving object. Inertial navigation is not only autonomous, real-time, continuous, hidden, undisturbed but also no time-limited and environment-limited. The gyroscope is the core component of the inertial navigation system, whose precision and size are the bottleneck of the performance. However, nuclear magnetic resonance gyroscope is characteristic of the advantage of high precision and small size. Nuclear magnetic resonance gyroscope can meet the urgent needs of high-tech weapons and equipment development of new generation. This paper mainly designs a set of photoelectric signal processing system for nuclear magnetic resonance gyroscope based on FPGA, which process and control the information of detecting laser .The photoelectric signal with high frequency carrier is demodulated by in-phase and quadrature demodulation method. Finally, the processing system of photoelectric signal can compensate the residual magnetism of the shielding barrel and provide the information of nuclear magnetic resonance gyroscope angular velocity.

  1. Adaptive Global Sliding Mode Control for MEMS Gyroscope Using RBF Neural Network

    Directory of Open Access Journals (Sweden)

    Yundi Chu

    2015-01-01

    Full Text Available An adaptive global sliding mode control (AGSMC using RBF neural network (RBFNN is proposed for the system identification and tracking control of micro-electro-mechanical system (MEMS gyroscope. Firstly, a new kind of adaptive identification method based on the global sliding mode controller is designed to update and estimate angular velocity and other system parameters of MEMS gyroscope online. Moreover, the output of adaptive neural network control is used to adjust the switch gain of sliding mode control dynamically to approach the upper bound of unknown disturbances. In this way, the switch item of sliding mode control can be converted to the output of continuous neural network which can weaken the chattering in the sliding mode control in contrast to the conventional fixed gain sliding mode control. Simulation results show that the designed control system can get satisfactory tracking performance and effective estimation of unknown parameters of MEMS gyroscope.

  2. A low noise photoelectric signal acquisition system applying in nuclear magnetic resonance gyroscope

    Science.gov (United States)

    Lu, Qilin; Zhang, Xian; Zhao, Xinghua; Yang, Dan; Zhou, Binquan; Hu, Zhaohui

    2017-10-01

    The nuclear magnetic resonance gyroscope serves as a new generation of strong support for the development of high-tech weapons, it solves the core problem that limits the development of the long-playing seamless navigation and positioning. In the NMR gyroscope, the output signal with atomic precession frequency is detected by the probe light, the final crucial photoelectric signal of the probe light directly decides the quality of the gyro signal. But the output signal has high sensitivity, resolution and measurement accuracy for the photoelectric detection system. In order to detect the measured signal better, this paper proposed a weak photoelectric signal rapid acquisition system, which has high SNR and the frequency of responded signal is up to 100 KHz to let the weak output signal with high frequency of the NMR gyroscope can be detected better.

  3. Multifrequency Excitation Method for Rapid and Accurate Dynamic Test of Micromachined Gyroscope Chips

    Directory of Open Access Journals (Sweden)

    Yan Deng

    2014-10-01

    Full Text Available A novel multifrequency excitation (MFE method is proposed to realize rapid and accurate dynamic testing of micromachined gyroscope chips. Compared with the traditional sweep-frequency excitation (SFE method, the computational time for testing one chip under four modes at a 1-Hz frequency resolution and 600-Hz bandwidth was dramatically reduced from 10 min to 6 s. A multifrequency signal with an equal amplitude and initial linear-phase-difference distribution was generated to ensure test repeatability and accuracy. The current test system based on LabVIEW using the SFE method was modified to use the MFE method without any hardware changes. The experimental results verified that the MFE method can be an ideal solution for large-scale dynamic testing of gyroscope chips and gyroscopes.

  4. Bifurcation Analysis and Spatiotemporal Patterns in Unidirectionally Delay-Coupled Vibratory Gyroscopes

    Science.gov (United States)

    Li, Li; Xu, Jian

    Time delay is inevitable in unidirectionally coupled drive-free vibratory gyroscope system. The effect of time delay on the gyroscope system is studied in this paper. To this end, amplitude death and Hopf bifurcation induced by small time delay are first investigated by analyzing the related characteristic equation. Then, the direction of Hopf bifurcations and stability of Hopf-bifurcating periodic oscillations are determined by calculating the normal form on the center manifold. Next, spatiotemporal patterns of these Hopf-bifurcating periodic oscillations are analyzed by using the symmetric bifurcation theory of delay differential equations. Finally, it is found that numerical simulations agree with the associated analytic results. These phenomena could be induced although time delay is very small. Therefore, it is shown that time delay is an important factor which influences the sensitivity and accuracy of the gyroscope system and cannot be neglected during the design and manufacture.

  5. Enhanced sensitivity in a butterfly gyroscope with a hexagonal oblique beam

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Dingbang; Cao, Shijie; Hou, Zhanqiang, E-mail: houzhanqiang@nudt.edu.cn; Chen, Zhihua; Wang, Xinghua; Wu, Xuezhong [College of Mechatronics Engineering and Automation, National University of Defense Technology, Changsha, Hunan, 410073 (China)

    2015-04-15

    A new approach to improve the performance of a butterfly gyroscope is developed. The methodology provides a simple way to improve the gyroscope’s sensitivity and stability, by reducing the resonant frequency mismatch between the drive and sense modes. This method was verified by simulations and theoretical analysis. The size of the hexagonal section oblique beam is the major factor that influences the resonant frequency mismatch. A prototype, which has the appropriately sized oblique beam, was fabricated using precise, time-controlled multilayer pre-buried masks. The performance of this prototype was compared with a non-tuned gyroscope. The scale factor of the prototype reaches 30.13 mV/ °/s, which is 15 times larger than that obtained from the non-tuned gyroscope. The bias stability of the prototype is 0.8 °/h, which is better than the 5.2 °/h of the non-tuned devices.

  6. Consideration of Gyroscopic Effect in Fault Detection and Isolation for Unbalance Excited Rotor Systems

    Directory of Open Access Journals (Sweden)

    Zhentao Wang

    2012-01-01

    Full Text Available Fault detection and isolation (FDI in rotor systems often faces the problem that the system dynamics is dependent on the rotor rotary frequency because of the gyroscopic effect. In unbalance excited rotor systems, the continuously distributed unbalances are hard to be determined or estimated accurately. The unbalance forces as disturbances make fault detection more complicated. The aim of this paper is to develop linear time invariant (LTI FDI methods (i.e., with constant parameters for rotor systems under consideration of gyroscopic effect and disturbances. Two approaches to describe the gyroscopic effect, that is, as unknown inputs and as model uncertainties, are investigated. Based on these two approaches, FDI methods are developed and the results are compared regarding the resulting FDI performances. Results are obtained by the application in a rotor test rig. Restrictions for the application of these methods are discussed.

  7. Significance of size dependent and material structure coupling on the characteristics and performance of nanocrystalline micro/nano gyroscopes

    Science.gov (United States)

    Larkin, K.; Ghommem, M.; Abdelkefi, A.

    2018-05-01

    Capacitive-based sensing microelectromechanical (MEMS) and nanoelectromechanical (NEMS) gyroscopes have significant advantages over conventional gyroscopes, such as low power consumption, batch fabrication, and possible integration with electronic circuits. However, inadequacies in the modeling of these inertial sensors have presented issues of reliability and functionality of micro-/nano-scale gyroscopes. In this work, a micromechanical model is developed to represent the unique microstructure of nanocrystalline materials and simulate the response of micro-/nano-gyroscope comprising an electrostatically-actuated cantilever beam with a tip mass at the free end. Couple stress and surface elasticity theories are integrated into the classical Euler-Bernoulli beam model in order to derive a size-dependent model. This model is then used to investigate the influence of size-dependent effects on the static pull-in instability, the natural frequencies and the performance output of gyroscopes as the scale decreases from micro-to nano-scale. The simulation results show significant changes in the static pull-in voltage and the natural frequency as the scale of the system is decreased. However, the differential frequency between the two vibration modes of the gyroscope is observed to drastically decrease as the size of the gyroscope is reduced. As such, the frequency-based operation mode may not be an efficient strategy for nano-gyroscopes. The results show that a strong coupling between the surface elasticity and material structure takes place when smaller grain sizes and higher void percentages are considered.

  8. Null result for violation of the equivalence principle with free-fall rotating gyroscopes

    International Nuclear Information System (INIS)

    Luo, J.; Zhou, Z.B.; Nie, Y.X.; Zhang, Y.Z.

    2002-01-01

    The differential acceleration between a rotating mechanical gyroscope and a nonrotating one is directly measured by using a double free-fall interferometer, and no apparent differential acceleration has been observed at the relative level of 2x10 -6 . It means that the equivalence principle is still valid for rotating extended bodies, i.e., the spin-gravity interaction between the extended bodies has not been observed at this level. Also, to the limit of our experimental sensitivity, there is no observed asymmetrical effect or antigravity of the rotating gyroscopes as reported by Hayasaka et al

  9. Design and analysis of a novel dual-mass MEMS resonant output gyroscope

    Directory of Open Access Journals (Sweden)

    Yang Gao

    2018-02-01

    Full Text Available This paper presents the design and analysis of a novel dual-mass microelectromechanical systems (MEMS resonant output gyroscope (ROG, which can effectively eliminate the influence of common-mode disturbance, such as the linear acceleration, on the gyroscope working mode by the design of dual-mass form, as well as on the frequency outputs of the double-ended tuning fork (DETF resonators by the differential arrangement. The concept of the ROG is introduced first. Then the dynamics of the gyroscope and the force-frequency characteristics of the DETF resonator are theoretically analyzed. By establishing the distribution coefficient of force and the reasonable equivalent of the force-frequency characteristics of the DETF resonator, the accurate expression of the device sensitivity is obtained. Based on the analysis results, the leverage mechanism and the DETF resonator are designed in detail. Then the configuration of the gyroscope, a dual-mass structure, is given. Finally, the validity of the analysis and design are verified by numerical simulations.

  10. Cascaded Kalman and particle filters for photogrammetry based gyroscope drift and robot attitude estimation.

    Science.gov (United States)

    Sadaghzadeh N, Nargess; Poshtan, Javad; Wagner, Achim; Nordheimer, Eugen; Badreddin, Essameddin

    2014-03-01

    Based on a cascaded Kalman-Particle Filtering, gyroscope drift and robot attitude estimation method is proposed in this paper. Due to noisy and erroneous measurements of MEMS gyroscope, it is combined with Photogrammetry based vision navigation scenario. Quaternions kinematics and robot angular velocity dynamics with augmented drift dynamics of gyroscope are employed as system state space model. Nonlinear attitude kinematics, drift and robot angular movement dynamics each in 3 dimensions result in a nonlinear high dimensional system. To reduce the complexity, we propose a decomposition of system to cascaded subsystems and then design separate cascaded observers. This design leads to an easier tuning and more precise debugging from the perspective of programming and such a setting is well suited for a cooperative modular system with noticeably reduced computation time. Kalman Filtering (KF) is employed for the linear and Gaussian subsystem consisting of angular velocity and drift dynamics together with gyroscope measurement. The estimated angular velocity is utilized as input of the second Particle Filtering (PF) based observer in two scenarios of stochastic and deterministic inputs. Simulation results are provided to show the efficiency of the proposed method. Moreover, the experimental results based on data from a 3D MEMS IMU and a 3D camera system are used to demonstrate the efficiency of the method. © 2013 ISA Published by ISA All rights reserved.

  11. GNSS Signal Tracking Performance Improvement for Highly Dynamic Receivers by Gyroscopic Mounting Crystal Oscillator.

    Science.gov (United States)

    Abedi, Maryam; Jin, Tian; Sun, Kewen

    2015-08-31

    In this paper, the efficiency of the gyroscopic mounting method is studied for a highly dynamic GNSS receiver's reference oscillator for reducing signal loss. Analyses are performed separately in two phases, atmospheric and upper atmospheric flights. Results show that the proposed mounting reduces signal loss, especially in parts of the trajectory where its probability is the highest. This reduction effect appears especially for crystal oscillators with a low elevation angle g-sensitivity vector. The gyroscopic mounting influences frequency deviation or jitter caused by dynamic loads on replica carrier and affects the frequency locked loop (FLL) as the dominant tracking loop in highly dynamic GNSS receivers. In terms of steady-state load, the proposed mounting mostly reduces the frequency deviation below the one-sigma threshold of FLL (1σ(FLL)). The mounting method can also reduce the frequency jitter caused by sinusoidal vibrations and reduces the probability of signal loss in parts of the trajectory where the other error sources accompany this vibration load. In the case of random vibration, which is the main disturbance source of FLL, gyroscopic mounting is even able to suppress the disturbances greater than the three-sigma threshold of FLL (3σ(FLL)). In this way, signal tracking performance can be improved by the gyroscopic mounting method for highly dynamic GNSS receivers.

  12. Analysis of the Gyroscopic Stabilization of a System of Rigid Bodies

    DEFF Research Database (Denmark)

    Kliem, Wolfhard; Kliem, Wolfhard

    1996-01-01

    We study the gyroscopic of a three-body system. A new method offinding stability regions, based on mechanism and criteria for gyroscopicstabilization, is presented. Of particular interest in this connection isthe theory of interaction of eigenvalues. This leads to a complete 3-dimensionalanalysis......, which shows the regions of stability, divergence, and flutter ofa simple model of a rotating spaceship....

  13. Application of MEMS Accelerometers and Gyroscopes in Fast Steering Mirror Control Systems

    Directory of Open Access Journals (Sweden)

    Jing Tian

    2016-03-01

    Full Text Available In a charge-coupled device (CCD-based fast steering mirror (FSM tracking control system, high control bandwidth is the most effective way to enhance the closed-loop performance. However, the control system usually suffers a great deal from mechanical resonances and time delays induced by the low sampling rate of CCDs. To meet the requirements of high precision and load restriction, fiber-optic gyroscopes (FOGs are usually used in traditional FSM tracking control systems. In recent years, the MEMS accelerometer and gyroscope are becoming smaller and lighter and their performance have improved gradually, so that they can be used in a fast steering mirror (FSM to realize the stabilization of the line-of-sight (LOS of the control system. Therefore, a tentative approach to implement a CCD-based FSM tracking control system, which uses MEMS accelerometers and gyroscopes as feedback components and contains an acceleration loop, a velocity loop and a position loop, is proposed. The disturbance suppression of the proposed method is the product of the error attenuation of the acceleration loop, the velocity loop and the position loop. Extensive experimental results show that the MEMS accelerometers and gyroscopes can act the similar role as the FOG with lower cost for stabilizing the LOS of the FSM tracking control system.

  14. A universal gyroscope driving circuit with 70dB amplitude control range

    KAUST Repository

    Abdelghany, Mohamed A.

    2010-08-01

    A CMOS variable gain driving circuit with output signal amplitude control for gyroscopes with wide range of quality factors is presented. The driving circuit can be used for gyroscopes with Q values higher than 500. The circuit uses a current-commutating switching mixer to control the gyroscope driving signal level. Conventional driving circuits use automatic gain control (AGC) which suffers from limited linear range and the need for an off-chip capacitor for the peak detector and loop filter. Two stage variable gain amplifier is used in the proposed design to ensure enough gain for oscillation for such a wide range of quality factors. Analog and digital amplitude control methods are used to cover wide range of driving signal amplitude with enough accuracy to hit the maximum driving signal level without sacrificing gyroscope linearity. Due to the high DC gain of the amplifier chain, DC offset resulting from mismatches might saturate the amplifier output. DC offset correction is employed using a secondary negative feedback loop. The proposed driving circuit is being fabricated in 0.6μm CMOS technology. © 2010 IEEE.

  15. Study on VCSEL laser heating chip in nuclear magnetic resonance gyroscope

    Science.gov (United States)

    Liang, Xiaoyang; Zhou, Binquan; Wu, Wenfeng; Jia, Yuchen; Wang, Jing

    2017-10-01

    In recent years, atomic gyroscope has become an important direction of inertial navigation. Nuclear magnetic resonance gyroscope has a stronger advantage in the miniaturization of the size. In atomic gyroscope, the lasers are indispensable devices which has an important effect on the improvement of the gyroscope performance. The frequency stability of the VCSEL lasers requires high precision control of temperature. However, the heating current of the laser will definitely bring in the magnetic field, and the sensitive device, alkali vapor cell, is very sensitive to the magnetic field, so that the metal pattern of the heating chip should be designed ingeniously to eliminate the magnetic field introduced by the heating current. In this paper, a heating chip was fabricated by MEMS process, i.e. depositing platinum on semiconductor substrates. Platinum has long been considered as a good resistance material used for measuring temperature The VCSEL laser chip is fixed in the center of the heating chip. The thermometer resistor measures the temperature of the heating chip, which can be considered as the same temperature of the VCSEL laser chip, by turning the temperature signal into voltage signal. The FPGA chip is used as a micro controller, and combined with PID control algorithm constitute a closed loop control circuit. The voltage applied to the heating resistor wire is modified to achieve the temperature control of the VCSEL laser. In this way, the laser frequency can be controlled stably and easily. Ultimately, the temperature stability can be achieved better than 100mK.

  16. Dynamical Behavior of a Rigid Body with One Fixed Point (Gyroscope. Basic Concepts and Results. Open Problems: a Review

    Directory of Open Access Journals (Sweden)

    Svetoslav Ganchev Nikolov

    2015-07-01

    Full Text Available The study of the dynamic behavior of a rigid body with one fixed point (gyroscope has a long history. A number of famous mathematicians and mechanical engineers have devoted enormous time and effort to clarify the role of dynamic effects on its movement (behavior – stable, periodic, quasi-periodic or chaotic. The main objectives of this review are: 1 to outline the characteristic features of the theory of dynamical systems and 2 to reveal the specific properties of the motion of a rigid body with one fixed point (gyroscope.This article consists of six sections. The first section addresses the main concepts of the theory of dynamical systems. Section two presents the main theoretical results (obtained so far concerning the dynamic behavior of a solid with one fixed point (gyroscope. Section three examines the problem of gyroscopic stabilization. Section four deals with the non-linear (chaotic dynamics of the gyroscope. Section five is a brief analysis of the gyroscope applications in engineering. The final section provides conclusions and generalizations on why the theory of dynamical systems should be used in the study of the movement of gyroscopic systems.

  17. Fabrication and analysis of a micro-machined tri-axis gyroscope

    Science.gov (United States)

    Tsai, Nan-Chyuan; Sue, Chung-Yang

    2008-11-01

    This paper presents an innovative micro-gyroscope design. Solely by SOI (silicon on insulator) fabrication technology and wet etching, the proposed micro-gyroscope can be produced in batch and is capable of detecting three-axis angular rates. The induced motions of all individual seismic mass modules are designed to respond in the directions orthogonal to each other in order to decouple the obtained measurements. In our work, three pairs of high-resolution differential capacitors with signal processing circuits are employed to measure the angular velocity components in three axes. On the other hand, the drive electrode comb is used to constantly vibrate the outer-ring in the tangential direction by a sinusoidal voltage. The signal bandwidth is increased by distributed translational proof masses (DTPM), placed 90° apart orderly. Each individual proof mass of DTPM is designed with natural frequency discrepancy and constrained to move in the radial direction so that the superior mode matching can be easily, to some extent, achieved. The suspension flexures are particularly designed to resist planar displacements in the drive mode but increase the stroke of tilting angular displacement in the sense mode. By considering the complicated geometry of the suspension flexures, FEM (finite element method) is employed to examine the potential maximum induced mechanical stress. The dynamic equations of the proposed gyroscope are established so that the embedded gyroscopic effects are explicitly unveiled. More importantly, the efficacy of the drive and sense circuit modules are verified by commercial softwares Hspice and Multisim. By intensive computer simulations and preliminary experimental studies, the resolution, bandwidth and decoupling capability of the tri-axis gyroscope are expected to be fairly enhanced if a certain degree of trade-off is preset.Corrections were made to figure 5 in this article on 3 October 2008. The corrected electronic version is identical to the

  18. Fabrication and analysis of a micro-machined tri-axis gyroscope

    International Nuclear Information System (INIS)

    Tsai, Nan-Chyuan; Sue, Chung-Yang

    2008-01-01

    This paper presents an innovative micro-gyroscope design. Solely by SOI (silicon on insulator) fabrication technology and wet etching, the proposed micro-gyroscope can be produced in batch and is capable of detecting three-axis angular rates. The induced motions of all individual seismic mass modules are designed to respond in the directions orthogonal to each other in order to decouple the obtained measurements. In our work, three pairs of high-resolution differential capacitors with signal processing circuits are employed to measure the angular velocity components in three axes. On the other hand, the drive electrode comb is used to constantly vibrate the outer-ring in the tangential direction by a sinusoidal voltage. The signal bandwidth is increased by distributed translational proof masses (DTPM), placed 90° apart orderly. Each individual proof mass of DTPM is designed with natural frequency discrepancy and constrained to move in the radial direction so that the superior mode matching can be easily, to some extent, achieved. The suspension flexures are particularly designed to resist planar displacements in the drive mode but increase the stroke of tilting angular displacement in the sense mode. By considering the complicated geometry of the suspension flexures, FEM (finite element method) is employed to examine the potential maximum induced mechanical stress. The dynamic equations of the proposed gyroscope are established so that the embedded gyroscopic effects are explicitly unveiled. More importantly, the efficacy of the drive and sense circuit modules are verified by commercial softwares Hspice and Multisim. By intensive computer simulations and preliminary experimental studies, the resolution, bandwidth and decoupling capability of the tri-axis gyroscope are expected to be fairly enhanced if a certain degree of trade-off is preset. Corrections were made to figure 5 in this article on 3 October 2008. The corrected electronic version is identical to the

  19. A comprehensive comparison of simple step counting techniques using wrist- and ankle-mounted accelerometer and gyroscope signals.

    Science.gov (United States)

    Rhudy, Matthew B; Mahoney, Joseph M

    2018-04-01

    The goal of this work is to compare the differences between various step counting algorithms using both accelerometer and gyroscope measurements from wrist and ankle-mounted sensors. Participants completed four different conditions on a treadmill while wearing an accelerometer and gyroscope on the wrist and the ankle. Three different step counting techniques were applied to the data from each sensor type and mounting location. It was determined that using gyroscope measurements allowed for better performance than the typically used accelerometers, and that ankle-mounted sensors provided better performance than those mounted on the wrist.

  20. Nanoscale quantum gyroscope using a single 13C nuclear spin coupled with a nearby NV center in diamond

    Science.gov (United States)

    Song, Xuerui; Wang, Liujun; Feng, Fupan; Lou, Liren; Diao, Wenting; Duan, Chongdi

    2018-03-01

    Developing gyroscopes based on quantum systems are important for inertial sensing applications, and its underlying physics is of fundamental interest. In this paper, we proposed a new type of gyroscope based on the Berry phase generated during rotation of the quantum system by using a single 13C nuclear spin coupled with a nearby nitrogen-vacancy center in diamond. Due to the atom-scale size of the quantum system, rotation information can be obtained with high spatial resolution. The gyroscope can be manipulated at room temperature and without the need for a strong magnetic field, which is also beneficial to its further applications.

  1. Development of thin film encapsulation process for piezoresistive MEMS gyroscope with wide gaps

    Science.gov (United States)

    Ayanoor-Vitikkate, Vipin

    The gyroscope is an inertial sensor used to measure the angular rate of a rotating object. This helps to determine the pitch and yaw rate of any moving body. A number of applications have been developed for consumer and automotive markets, for e.g. vehicle stability control, navigation assist, roll over detection. These are primarily used in high-end cars, where cost is not a major factor. Other areas where a MEMS Gyro can be used are robotics, camcorder stabilization, virtual reality, and more. Primarily due to cost and the size most of these applications have not reached any significant volume. One reason for this is the relatively high cost of MEMS gyros compared to other MEMS sensors like accelerometers or pressure sensors. Generally the cost of packaging a MEMS sensor is about 85-90% of the total cost. Currently most MEMS based gyroscopes are made using bulk or surface micromachining, after which they are packaged using wafer bonding. This unfortunately leads to wastage of silicon and increase in the package size, thus reducing the yield. One way to reduce the cost of packaging is by wafer scale thin film encapsulation of MEMS gyroscopes. The goal of the present work is to fabricate a rate grade MEMS gyroscope and encapsulate it by modifying an existing thin-film encapsulation technique. Packaging is an important step towards commercialization of the device and we plan to use thin wafer scale encapsulation technique developed previously in our group to package these devices. The silicon micro machined gyroscope will be fabricated on SOI (Silicon-on-Insulator) wafers using Bosch DRIE etching techniques. The encapsulation of the device is carried out using epitaxial polysilicon in order to provide a high vacuum inside the device chamber. The advantages offered by this technique are the reduction in area of the die and thus less silicon surface is wasted. In addition to this the encapsulation technique helps in creating a vacuum inside the micro device, which

  2. An adaptive compensation algorithm for temperature drift of micro-electro-mechanical systems gyroscopes using a strong tracking Kalman filter.

    Science.gov (United States)

    Feng, Yibo; Li, Xisheng; Zhang, Xiaojuan

    2015-05-13

    We present an adaptive algorithm for a system integrated with micro-electro-mechanical systems (MEMS) gyroscopes and a compass to eliminate the influence from the environment, compensate the temperature drift precisely, and improve the accuracy of the MEMS gyroscope. We use a simplified drift model and changing but appropriate model parameters to implement this algorithm. The model of MEMS gyroscope temperature drift is constructed mostly on the basis of the temperature sensitivity of the gyroscope. As the state variables of a strong tracking Kalman filter (STKF), the parameters of the temperature drift model can be calculated to adapt to the environment under the support of the compass. These parameters change intelligently with the environment to maintain the precision of the MEMS gyroscope in the changing temperature. The heading error is less than 0.6° in the static temperature experiment, and also is kept in the range from 5° to -2° in the dynamic outdoor experiment. This demonstrates that the proposed algorithm exhibits strong adaptability to a changing temperature, and performs significantly better than KF and MLR to compensate the temperature drift of a gyroscope and eliminate the influence of temperature variation.

  3. An Adaptive Compensation Algorithm for Temperature Drift of Micro-Electro-Mechanical Systems Gyroscopes Using a Strong Tracking Kalman Filter

    Directory of Open Access Journals (Sweden)

    Yibo Feng

    2015-05-01

    Full Text Available We present an adaptive algorithm for a system integrated with micro-electro-mechanical systems (MEMS gyroscopes and a compass to eliminate the influence from the environment, compensate the temperature drift precisely, and improve the accuracy of the MEMS gyroscope. We use a simplified drift model and changing but appropriate model parameters to implement this algorithm. The model of MEMS gyroscope temperature drift is constructed mostly on the basis of the temperature sensitivity of the gyroscope. As the state variables of a strong tracking Kalman filter (STKF, the parameters of the temperature drift model can be calculated to adapt to the environment under the support of the compass. These parameters change intelligently with the environment to maintain the precision of the MEMS gyroscope in the changing temperature. The heading error is less than 0.6° in the static temperature experiment, and also is kept in the range from 5° to −2° in the dynamic outdoor experiment. This demonstrates that the proposed algorithm exhibits strong adaptability to a changing temperature, and performs significantly better than KF and MLR to compensate the temperature drift of a gyroscope and eliminate the influence of temperature variation.

  4. Calibration of atomic trajectories in a large-area dual-atom-interferometer gyroscope

    Science.gov (United States)

    Yao, Zhan-Wei; Lu, Si-Bin; Li, Run-Bing; Luo, Jun; Wang, Jin; Zhan, Ming-Sheng

    2018-01-01

    We propose and demonstrate a method for calibrating atomic trajectories in a large-area dual-atom-interferometer gyroscope. The atom trajectories are monitored by modulating and delaying the Raman transition, and they are precisely calibrated by controlling the laser orientation and the bias magnetic field. To improve the immunity to the gravity effect and the common phase noise, the symmetry and the overlap of two large-area atomic interference loops are optimized by calibrating the atomic trajectories and by aligning the Raman-laser orientations. The dual-atom-interferometer gyroscope is applied in the measurement of the Earth's rotation. The sensitivity is 1.2 ×10-6 rad s -1 Hz-1/2, and the long-term stability is 6.2 ×10-8 rad/s at 2000 s.

  5. Application of the vector modulation method to the north finder capability gyroscope as a directional sensor

    International Nuclear Information System (INIS)

    Celikel, Oguz

    2011-01-01

    This paper presents the application of the vector modulation method (VMM) to an open-loop interferometric fiber optic gyroscope, called the north finder capability gyroscope (NFCG), designed and assembled in TUBITAK UME (National Metrology Institute of Turkey). The method contains a secondary modulation/demodulation circuit with an AD630 chip, depending on the periodic variation of the orientation of the sensing coil sensitive surface vector with respect to geographic north at a laboratory latitude and collection of dc voltage at the secondary demodulation circuit output in the time domain. The resultant dc voltage proportional to the first-kind Bessel function based on Sagnac phase shift for the first order is obtained as a result of vector modulation together with the Earth's rotation. A new model function is developed and introduced to evaluate the angular errors of the NFCG with VMM in finding geographic north

  6. A single-ended CMOS sensing circuit for MEMS gyroscope with noise cancellation

    KAUST Repository

    Elsayed, Mohannad Yomn

    2010-06-01

    In this work, a complete single-ended readout circuit for capacitive MEMS gyroscope using chopper stabilization technique is presented. A novel noise cancellation technique is used to get rid of the bias noise. The circuit offers superior performance over state of the art readout circuits in terms of cost, gain, and noise for the given area and power consumption. The full circuit exhibits a gain of 58dB, a power dissipation of 1.3mW and an input referred noise of 12nV/√Hz. This would significantly improve the overall sensitivity of the gyroscope. The full circuit has been fabricated in 0.6um CMOS technology and it occupies an area of 0.4mm × 1mm. © 2010 IEEE.

  7. Generalized projective chaos synchronization of gyroscope systems subjected to dead-zone nonlinear inputs

    International Nuclear Information System (INIS)

    Yau, H.-T.

    2008-01-01

    This Letter presents a robust control scheme to generalized projective synchronization between two identical two-degrees-of-freedom heavy symmetric gyroscopes with dead zone nonlinear inputs. Because of the nonlinear terms of the gyroscope system, the system exhibits complex and chaotic motions. By the Lyapunov stability theory with control terms, two suitable sliding surfaces are proposed to ensure the stability of the controlled closed-loop system in sliding mode. Then, two sliding mode controllers (SMC) are designed to guarantee the hitting of the sliding surfaces even when the control inputs contain dead-zone nonlinearity. This method allows us to arbitrarily direct the scaling factor onto a desired value. Numerical simulations show that this method works very well for the proposed controller

  8. A single-ended CMOS sensing circuit for MEMS gyroscope with noise cancellation

    KAUST Repository

    Elsayed, Mohannad Yomn; Emira, Ahmed; Sedky, Sherif M.; Habib, S. E. D.

    2010-01-01

    In this work, a complete single-ended readout circuit for capacitive MEMS gyroscope using chopper stabilization technique is presented. A novel noise cancellation technique is used to get rid of the bias noise. The circuit offers superior performance over state of the art readout circuits in terms of cost, gain, and noise for the given area and power consumption. The full circuit exhibits a gain of 58dB, a power dissipation of 1.3mW and an input referred noise of 12nV/√Hz. This would significantly improve the overall sensitivity of the gyroscope. The full circuit has been fabricated in 0.6um CMOS technology and it occupies an area of 0.4mm × 1mm. © 2010 IEEE.

  9. Noise Reduction of MEMS Gyroscope Based on Direct Modeling for an Angular Rate Signal

    Directory of Open Access Journals (Sweden)

    Liang Xue

    2015-02-01

    Full Text Available In this paper, a novel approach for processing the outputs signal of the microelectromechanical systems (MEMS gyroscopes was presented to reduce the bias drift and noise. The principle for the noise reduction was presented, and an optimal Kalman filter (KF was designed by a steady-state filter gain obtained from the analysis of KF observability. In particular, the true angular rate signal was directly modeled to obtain an optimal estimate and make a self-compensation for the gyroscope without needing other sensor’s information, whether in static or dynamic condition. A linear fit equation that describes the relationship between the KF bandwidth and modeling parameter of true angular rate was derived from the analysis of KF frequency response. The test results indicated that the MEMS gyroscope having an ARW noise of 4.87°/h0.5 and a bias instability of 44.41°/h were reduced to 0.4°/h0.5 and 4.13°/h by the KF under a given bandwidth (10 Hz, respectively. The 1σ estimated error was reduced from 1.9°/s to 0.14°/s and 1.7°/s to 0.5°/s in the constant rate test and swing rate test, respectively. It also showed that the filtered angular rate signal could well reflect the dynamic characteristic of the input rate signal in dynamic conditions. The presented algorithm is proved to be effective at improving the measurement precision of the MEMS gyroscope.

  10. Reproducibility of a 3-dimensional gyroscope in measuring shoulder anteflexion and abduction

    Directory of Open Access Journals (Sweden)

    Penning Ludo I F

    2012-07-01

    Full Text Available Abstract Background Few studies have investigated the use of a 3-dimensional gyroscope for measuring the range of motion (ROM in the impaired shoulder. Reproducibility of digital inclinometer and visual estimation is poor. This study aims to investigate the reproducibility of a tri axial gyroscope in measurement of anteflexion, abduction and related rotations in the impaired shoulder. Methods Fifty-eight patients with either subacromial impingement (27 or osteoarthritis of the shoulder (31 participated. Active anteflexion, abduction and related rotations were measured with a tri axial gyroscope according to a test retest protocol. Severity of shoulder impairment and patient perceived pain were assessed by the Disability of Arm Shoulder and Hand score (DASH and the Visual Analogue Scale (VAS. VAS scores were recorded before and after testing. Results In two out of three hospitals patients with osteoarthritis (n = 31 were measured, in the third hospital patients with subacromial impingement (n = 27. There were significant differences among hospitals for the VAS and DASH scores measured before and after testing. The mean differences between the test and retest means for anteflexion were −6 degrees (affected side, 9 (contralateral side and for abduction 15 degrees (affected side and 10 degrees (contralateral side. Bland & Altman plots showed that the confidence intervals for the mean differences fall within −6 up to 15 degrees, individual test - retest differences could exceed these limits. A simulation according to ‘Generalizability Theory’ produces very good coefficients for anteflexion and related rotation as a comprehensive measure of reproducibility. Optimal reproducibility is achieved with 2 repetitions for anteflexion. Conclusions Measurements were influenced by patient perceived pain. Differences in VAS and DASH might be explained by different underlying pathology. These differences in shoulder pathology however did not alter

  11. Chip-Scale Combinatorial Atomic Navigator (C-SCAN) Low Drift Nuclear Spin Gyroscope

    Science.gov (United States)

    2018-01-01

    suggestions for reducing this burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704...spin-exchange relaxation in a finite magnetic field. We operated the gyroscope using a Ramsey-type interrogation sequence with nuclear spin precession...shift by a factor of 105. Here we use the approach of a Ramsey clock interrogation scheme, where the optical pumping, free evolution, and measurement

  12. From space qualified fiber optic gyroscope to generic fiber optic solutions available for space application

    Science.gov (United States)

    Buret, Thomas; Ramecourt, David; Napolitano, Fabien

    2017-11-01

    The aim of this article is to present how the qualification of the Fiber Optic Gyroscope technology from IXSEA has been achieved through the qualification of a large range of optical devices and related manufacturing processes. These qualified optical devices and processes, that are now fully mastered by IXSEA through vertical integration of the technology, can be used for other space optical sensors. The example of the SWARM project will be discussed.

  13. Project of a laser gyroscope to determine continuously the Earth's rotation.

    Science.gov (United States)

    Blinov, N. S.; Zharov, V. E.; Sazhin, M. V.; Fedoseev, E. N.; Vlasov, B. I.; Rusakov, V. K.

    The Time Service of the Sternberg State Astronomical Institute together with specialists of VNIIFTRI began to work at the project of the laser gyroscope to determine continuously the Earth's rotation. It is assumed to measure both the high-frequency variations with periods of 100 - 1000 sec and the low-frequency variations with periods of a few days. It gives the opportunity to combine these data with the VLBI data.

  14. A new systematic calibration method of ring laser gyroscope inertial navigation system

    Science.gov (United States)

    Wei, Guo; Gao, Chunfeng; Wang, Qi; Wang, Qun; Xiong, Zhenyu; Long, Xingwu

    2016-10-01

    Inertial navigation system has been the core component of both military and civil navigation systems. Before the INS is put into application, it is supposed to be calibrated in the laboratory in order to compensate repeatability error caused by manufacturing. Discrete calibration method cannot fulfill requirements of high-accurate calibration of the mechanically dithered ring laser gyroscope navigation system with shock absorbers. This paper has analyzed theories of error inspiration and separation in detail and presented a new systematic calibration method for ring laser gyroscope inertial navigation system. Error models and equations of calibrated Inertial Measurement Unit are given. Then proper rotation arrangement orders are depicted in order to establish the linear relationships between the change of velocity errors and calibrated parameter errors. Experiments have been set up to compare the systematic errors calculated by filtering calibration result with those obtained by discrete calibration result. The largest position error and velocity error of filtering calibration result are only 0.18 miles and 0.26m/s compared with 2 miles and 1.46m/s of discrete calibration result. These results have validated the new systematic calibration method and proved its importance for optimal design and accuracy improvement of calibration of mechanically dithered ring laser gyroscope inertial navigation system.

  15. Analysis of Dynamic Performance of a Kalman Filter for Combining Multiple MEMS Gyroscopes

    Directory of Open Access Journals (Sweden)

    Liang Xue

    2014-11-01

    Full Text Available In this paper, the dynamic performance of a Kalman filter (KF was analyzed, which is used to combine multiple measurements of a gyroscopes array to reduce the noise and improve the accuracy of the individual sensors. A principle for accuracy improvement by the KF was briefly presented to obtain an optimal estimate of input rate signal. In particular, the influences of some crucial factors on the KF dynamic performance were analyzed by simulations such as the factors input signal frequency, signal sampling, and KF filtering rate. Finally, a system that was comprised of a six-gyroscope array was designed and implemented to test the dynamic performance. Experimental results indicated that the 1σ error for the combined rate signal was reduced to about 0.2°/s in the constant rate test, which was a reduction by a factor of more than eight compared to the single gyroscope. The 1σ error was also reduced from 1.6°/s to 0.48°/s in the swing test. It showed that the estimated angular rate signal could well reflect the dynamic characteristic of the input signal in dynamic conditions.

  16. EVALUATION METHOD FOR PARASITIC EFFECTS OF THE ELECTRO-OPTICAL MODULATOR IN A FIBER OPTIC GYROSCOPE

    Directory of Open Access Journals (Sweden)

    S. A. Volkovskiy

    2016-09-01

    Full Text Available Subject of Research.The paper proposes an original method for studying the parasitic effects in the electro-optic modulator of the fiber optic gyroscope. Proposed method is based on the usage of a special waveform phase modulation signal. Method. The essence of the proposed method lies in modification of serrodyne modulation signal, thereby providing a periodic displacement of the phase difference signal to the maximum of the interference curve. In this case, the intensity level reflects the influence of parasitic effects with the degree of manifestation being determined by the sequence of voltage control signals applied to the modulator. Enumeration of combinations of control signals and the corresponding intensity levels gives the possibility to observe an empirical dependence of the parasitic effects and use it later for compensation. Main Results. The efficiency of the proposed method is demonstrated by the program model of the fiber optic gyroscope. The results of the method application on a production sample of the device were obtained. Comparison with the results of direct estimate of the parasitic intensity modulation effect testifies to the effectiveness of the proposed method. Practical Relevance. The method can be used as a diagnostic tool to quantify the influence of parasitic effects in the electro-optic modulator of the fiber optic gyroscope as well as for their subsequent compensation.

  17. Structural-acoustic coupling effects on the non-vacuum packaging vibratory cylinder gyroscope.

    Science.gov (United States)

    Xi, Xiang; Wu, Xuezhong; Wu, Yulie; Zhang, Yongmeng; Tao, Yi; Zheng, Yu; Xiao, Dingbang

    2013-12-13

    The resonant shells of vibratory cylinder gyroscopes are commonly packaged in metallic caps. In order to lower the production cost, a portion of vibratory cylinder gyroscopes do not employ vacuum packaging. However, under non-vacuum packaging conditions there can be internal acoustic noise leading to considerable acoustic pressure which is exerted on the resonant shell. Based on the theory of the structural-acoustic coupling, the dynamical behavior of the resonant shell under acoustic pressure is presented in this paper. A finite element (FE) model is introduced to quantitatively analyze the effect of the structural-acoustic coupling. Several main factors, such as sealing cap sizes and degree of vacuum which directly affect the vibration of the resonant shell, are studied. The results indicate that the vibration amplitude and the operating frequency of the resonant shell will be changed when the effect of structural-acoustic coupling is taken into account. In addition, an experiment was set up to study the effect of structural-acoustic coupling on the sensitivity of the gyroscope. A 32.4 mV/°/s increase of the scale factor and a 6.2 Hz variation of the operating frequency were observed when the radial gap size between the resonant shell and the sealing cap was changed from 0.5 mm to 20 mm.

  18. Structural-Acoustic Coupling Effects on the Non-Vacuum Packaging Vibratory Cylinder Gyroscope

    Directory of Open Access Journals (Sweden)

    Xiang Xi

    2013-12-01

    Full Text Available The resonant shells of vibratory cylinder gyroscopes are commonly packaged in metallic caps. In order to lower the production cost, a portion of vibratory cylinder gyroscopes do not employ vacuum packaging. However, under non-vacuum packaging conditions there can be internal acoustic noise leading to considerable acoustic pressure which is exerted on the resonant shell. Based on the theory of the structural-acoustic coupling, the dynamical behavior of the resonant shell under acoustic pressure is presented in this paper. A finite element (FE model is introduced to quantitatively analyze the effect of the structural-acoustic coupling. Several main factors, such as sealing cap sizes and degree of vacuum which directly affect the vibration of the resonant shell, are studied. The results indicate that the vibration amplitude and the operating frequency of the resonant shell will be changed when the effect of structural-acoustic coupling is taken into account. In addition, an experiment was set up to study the effect of structural-acoustic coupling on the sensitivity of the gyroscope. A 32.4 mV/°/s increase of the scale factor and a 6.2 Hz variation of the operating frequency were observed when the radial gap size between the resonant shell and the sealing cap was changed from 0.5 mm to 20 mm.

  19. Signal Quality Improvement Algorithms for MEMS Gyroscope-Based Human Motion Analysis Systems: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Jiaying Du

    2018-04-01

    Full Text Available Motion sensors such as MEMS gyroscopes and accelerometers are characterized by a small size, light weight, high sensitivity, and low cost. They are used in an increasing number of applications. However, they are easily influenced by environmental effects such as temperature change, shock, and vibration. Thus, signal processing is essential for minimizing errors and improving signal quality and system stability. The aim of this work is to investigate and present a systematic review of different signal error reduction algorithms that are used for MEMS gyroscope-based motion analysis systems for human motion analysis or have the potential to be used in this area. A systematic search was performed with the search engines/databases of the ACM Digital Library, IEEE Xplore, PubMed, and Scopus. Sixteen papers that focus on MEMS gyroscope-related signal processing and were published in journals or conference proceedings in the past 10 years were found and fully reviewed. Seventeen algorithms were categorized into four main groups: Kalman-filter-based algorithms, adaptive-based algorithms, simple filter algorithms, and compensation-based algorithms. The algorithms were analyzed and presented along with their characteristics such as advantages, disadvantages, and time limitations. A user guide to the most suitable signal processing algorithms within this area is presented.

  20. Signal Quality Improvement Algorithms for MEMS Gyroscope-Based Human Motion Analysis Systems: A Systematic Review.

    Science.gov (United States)

    Du, Jiaying; Gerdtman, Christer; Lindén, Maria

    2018-04-06

    Motion sensors such as MEMS gyroscopes and accelerometers are characterized by a small size, light weight, high sensitivity, and low cost. They are used in an increasing number of applications. However, they are easily influenced by environmental effects such as temperature change, shock, and vibration. Thus, signal processing is essential for minimizing errors and improving signal quality and system stability. The aim of this work is to investigate and present a systematic review of different signal error reduction algorithms that are used for MEMS gyroscope-based motion analysis systems for human motion analysis or have the potential to be used in this area. A systematic search was performed with the search engines/databases of the ACM Digital Library, IEEE Xplore, PubMed, and Scopus. Sixteen papers that focus on MEMS gyroscope-related signal processing and were published in journals or conference proceedings in the past 10 years were found and fully reviewed. Seventeen algorithms were categorized into four main groups: Kalman-filter-based algorithms, adaptive-based algorithms, simple filter algorithms, and compensation-based algorithms. The algorithms were analyzed and presented along with their characteristics such as advantages, disadvantages, and time limitations. A user guide to the most suitable signal processing algorithms within this area is presented.

  1. Analysis of Correlation in MEMS Gyroscope Array and its Influence on Accuracy Improvement for the Combined Angular Rate Signal

    Directory of Open Access Journals (Sweden)

    Liang Xue

    2018-01-01

    Full Text Available Obtaining a correlation factor is a prerequisite for fusing multiple outputs of a mircoelectromechanical system (MEMS gyroscope array and evaluating accuracy improvement. In this paper, a mathematical statistics method is established to analyze and obtain the practical correlation factor of a MEMS gyroscope array, which solves the problem of determining the Kalman filter (KF covariance matrix Q and fusing the multiple gyroscope signals. The working principle and mathematical model of the sensor array fusion is briefly described, and then an optimal estimate of input rate signal is achieved by using of a steady-state KF gain in an off-line estimation approach. Both theoretical analysis and simulation show that the negative correlation factor has a favorable influence on accuracy improvement. Additionally, a four-gyro array system composed of four discrete individual gyroscopes was developed to test the correlation factor and its influence on KF accuracy improvement. The result showed that correlation factors have both positive and negative values; in particular, there exist differences for correlation factor between the different units in the array. The test results also indicated that the Angular Random Walk (ARW of 1.57°/h0.5 and bias drift of 224.2°/h for a single gyroscope were reduced to 0.33°/h0.5 and 47.8°/h with some negative correlation factors existing in the gyroscope array, making a noise reduction factor of about 4.7, which is higher than that of a uncorrelated four-gyro array. The overall accuracy of the combined angular rate signal can be further improved if the negative correlation factors in the gyroscope array become larger.

  2. A novel oscillation control for MEMS vibratory gyroscopes using a modified electromechanical amplitude modulation technique

    International Nuclear Information System (INIS)

    Ma, Wei; Lin, Yiyu; Liu, Siqi; Zheng, Xudong; Jin, Zhonghe

    2017-01-01

    This paper reports a novel oscillation control algorithm for MEMS vibratory gyroscopes using a modified electromechanical amplitude modulation (MEAM) technique, which enhances the robustness against the frequency variation of the driving mode, compared to the conventional EAM (CEAM) scheme. In this approach, the carrier voltage exerted on the proof mass is frequency-modulated by the drive resonant frequency. Accordingly, the pick-up signal from the interface circuit involves a constant-frequency component that contains the amplitude and phase information of the vibration displacement. In other words, this informational detection signal is independent of the mechanical resonant frequency, which varies due to different batches, imprecise micro-fabrication and changing environmental temperature. In this paper, the automatic gain control loop together with the phase-locked loop are simultaneously analyzed using the averaging method and Routh–Hurwitz criterion, deriving the stability condition and the parameter optimization rules of the transient response. Then, a simulation model based on the real system is set up to evaluate the control algorithm. Further, the proposed MEAM method is tested using a field-programmable-gate-array based digital platform on a capacitive vibratory gyroscope. By optimizing the control parameters, the transient response of the drive amplitude reveals a settling time of 45.2 ms without overshoot, according well with the theoretical prediction and simulation results. The first measurement results show that the amplitude variance of the drive displacement is 12 ppm in an hour while the phase standard deviation is as low as 0.0004°. The mode-split gyroscope operating under atmospheric pressure demonstrates an outstanding performance. By virtue of the proposed MEAM method, the bias instability and angle random walk are measured to be 0.9° h −1 (improved by 2.4 times compared to the CEAM method) and 0.068° (√h) −1 (improved by 1

  3. A dynamic system matching technique for improving the accuracy of MEMS gyroscopes

    Energy Technology Data Exchange (ETDEWEB)

    Stubberud, Peter A., E-mail: stubber@ee.unlv.edu [Department of Electrical and Computer Engineering, University of Nevada, Las Vegas, Las Vegas, NV 89154 (United States); Stubberud, Stephen C., E-mail: scstubberud@ieee.org [Oakridge Technology, San Diego, CA 92121 (United States); Stubberud, Allen R., E-mail: stubberud@att.net [Department of Electrical Engineering and Computer Science, University of California, Irvine, Irvine, CA 92697 (United States)

    2014-12-10

    A classical MEMS gyro transforms angular rates into electrical values through Euler's equations of angular rotation. Production models of a MEMS gyroscope will have manufacturing errors in the coefficients of the differential equations. The output signal of a production gyroscope will be corrupted by noise, with a major component of the noise due to the manufacturing errors. As is the case of the components in an analog electronic circuit, one way of controlling the variability of a subsystem is to impose extremely tight control on the manufacturing process so that the coefficient values are within some specified bounds. This can be expensive and may even be impossible as is the case in certain applications of micro-electromechanical (MEMS) sensors. In a recent paper [2], the authors introduced a method for combining the measurements from several nominally equal MEMS gyroscopes using a technique based on a concept from electronic circuit design called dynamic element matching [1]. Because the method in this paper deals with systems rather than elements, it is called a dynamic system matching technique (DSMT). The DSMT generates a single output by randomly switching the outputs of several, nominally identical, MEMS gyros in and out of the switch output. This has the effect of 'spreading the spectrum' of the noise caused by the coefficient errors generated in the manufacture of the individual gyros. A filter can then be used to eliminate that part of the spread spectrum that is outside the pass band of the gyro. A heuristic analysis in that paper argues that the DSMT can be used to control the effects of the random coefficient variations. In a follow-on paper [4], a simulation of a DSMT indicated that the heuristics were consistent. In this paper, analytic expressions of the DSMT noise are developed which confirm that the earlier conclusions are valid. These expressions include the various DSMT design parameters and, therefore, can be used as design

  4. Molecular gyroscopes and biological effects of weak extremely low-frequency magnetic fields

    International Nuclear Information System (INIS)

    Binhi, V.N.; Savin, A.V.

    2002-01-01

    Extremely low-frequency magnetic fields are known to affect biological systems. In many cases, biological effects display 'windows' in biologically effective parameters of the magnetic fields: most dramatic is the fact that the relatively intense magnetic fields sometimes do not cause appreciable effect, while smaller fields of the order of 10-100 μT do. Linear resonant physical processes do not explain the frequency windows in this case. Amplitude window phenomena suggest a nonlinear physical mechanism. Such a nonlinear mechanism has been proposed recently to explain those 'windows'. It considers the quantum-interference effects on the protein-bound substrate ions. Magnetic fields cause an interference of ion quantum states and change the probability of ion-protein dissociation. This ion-interference mechanism predicts specific magnetic-field frequency and amplitude windows within which the biological effects occur. It agrees with a lot of experiments. However, according to the mechanism, the lifetime Γ -1 of ion quantum states within a protein cavity should be of unrealistic value, more than 0.01 s for frequency band 10-100 Hz. In this paper, a biophysical mechanism has been proposed, which (i) retains the attractive features of the ion interference mechanism, i.e., predicts physical characteristics that might be experimentally examined and (ii) uses the principles of gyroscopic motion and removes the necessity to postulate large lifetimes. The mechanism considers the dynamics of the density matrix of the molecular groups, which are attached to the walls of protein cavities by two covalent bonds, i.e., molecular gyroscopes. Numerical computations have shown almost free rotations of the molecular gyroscopes. The relaxation time due to van der Waals forces was about 0.01 s for the cavity size of 28 Aa

  5. A dynamic system matching technique for improving the accuracy of MEMS gyroscopes

    International Nuclear Information System (INIS)

    Stubberud, Peter A.; Stubberud, Stephen C.; Stubberud, Allen R.

    2014-01-01

    A classical MEMS gyro transforms angular rates into electrical values through Euler's equations of angular rotation. Production models of a MEMS gyroscope will have manufacturing errors in the coefficients of the differential equations. The output signal of a production gyroscope will be corrupted by noise, with a major component of the noise due to the manufacturing errors. As is the case of the components in an analog electronic circuit, one way of controlling the variability of a subsystem is to impose extremely tight control on the manufacturing process so that the coefficient values are within some specified bounds. This can be expensive and may even be impossible as is the case in certain applications of micro-electromechanical (MEMS) sensors. In a recent paper [2], the authors introduced a method for combining the measurements from several nominally equal MEMS gyroscopes using a technique based on a concept from electronic circuit design called dynamic element matching [1]. Because the method in this paper deals with systems rather than elements, it is called a dynamic system matching technique (DSMT). The DSMT generates a single output by randomly switching the outputs of several, nominally identical, MEMS gyros in and out of the switch output. This has the effect of 'spreading the spectrum' of the noise caused by the coefficient errors generated in the manufacture of the individual gyros. A filter can then be used to eliminate that part of the spread spectrum that is outside the pass band of the gyro. A heuristic analysis in that paper argues that the DSMT can be used to control the effects of the random coefficient variations. In a follow-on paper [4], a simulation of a DSMT indicated that the heuristics were consistent. In this paper, analytic expressions of the DSMT noise are developed which confirm that the earlier conclusions are valid. These expressions include the various DSMT design parameters and, therefore, can be used as design

  6. A dynamic system matching technique for improving the accuracy of MEMS gyroscopes

    Science.gov (United States)

    Stubberud, Peter A.; Stubberud, Stephen C.; Stubberud, Allen R.

    2014-12-01

    A classical MEMS gyro transforms angular rates into electrical values through Euler's equations of angular rotation. Production models of a MEMS gyroscope will have manufacturing errors in the coefficients of the differential equations. The output signal of a production gyroscope will be corrupted by noise, with a major component of the noise due to the manufacturing errors. As is the case of the components in an analog electronic circuit, one way of controlling the variability of a subsystem is to impose extremely tight control on the manufacturing process so that the coefficient values are within some specified bounds. This can be expensive and may even be impossible as is the case in certain applications of micro-electromechanical (MEMS) sensors. In a recent paper [2], the authors introduced a method for combining the measurements from several nominally equal MEMS gyroscopes using a technique based on a concept from electronic circuit design called dynamic element matching [1]. Because the method in this paper deals with systems rather than elements, it is called a dynamic system matching technique (DSMT). The DSMT generates a single output by randomly switching the outputs of several, nominally identical, MEMS gyros in and out of the switch output. This has the effect of 'spreading the spectrum' of the noise caused by the coefficient errors generated in the manufacture of the individual gyros. A filter can then be used to eliminate that part of the spread spectrum that is outside the pass band of the gyro. A heuristic analysis in that paper argues that the DSMT can be used to control the effects of the random coefficient variations. In a follow-on paper [4], a simulation of a DSMT indicated that the heuristics were consistent. In this paper, analytic expressions of the DSMT noise are developed which confirm that the earlier conclusions are valid. These expressions include the various DSMT design parameters and, therefore, can be used as design tools for DSMT

  7. SCALE FACTOR DETERMINATION METHOD OF ELECTRO-OPTICAL MODULATOR IN FIBER-OPTIC GYROSCOPE

    Directory of Open Access Journals (Sweden)

    A. S. Aleynik

    2016-05-01

    Full Text Available Subject of Research. We propose a method for dynamic measurement of half-wave voltage of electro-optic modulator as part of a fiber optic gyroscope. Excluding the impact of the angular acceleration o​n measurement of the electro-optical coefficient is achieved through the use of homodyne demodulation method that allows a division of the Sagnac phase shift signal and an auxiliary signal for measuring the electro-optical coefficient in the frequency domain. Method. The method essence reduces to decomposition of step of digital serrodyne modulation in two parts with equal duration. The first part is used for quadrature modulation signals. The second part comprises samples of the auxiliary signal used to determine the value of the scale factor of the modulator. Modeling is done in standalone model, and as part of a general model of the gyroscope. The applicability of the proposed method is investigated as well as its qualitative and quantitative characteristics: absolute and relative accuracy of the electro-optic coefficient, the stability of the method to the effects of angular velocities and accelerations, method resistance to noise in actual devices. Main Results. The simulation has showed the ability to measure angular velocity changing under the influence of angular acceleration, acting on the device, and simultaneous measurement of electro-optical coefficient of the phase modulator without interference between these processes. Practical Relevance. Featured in the paper the ability to eliminate the influence of the angular acceleration on the measurement accuracy of the electro-optical coefficient of the phase modulator will allow implementing accurate measurement algorithms for fiber optic gyroscopes resistant to a significant acceleration in real devices.

  8. The effect of broadened linewidth induced by dispersion on the performance of resonant optical gyroscope

    Science.gov (United States)

    Zhang, Hao; Li, Wenxiu; Han, Peng; Chang, Xiaoyang; Liu, Jiaming; Lin, Jian; Xue, Xia; Zhu, Fang; Yang, Yang; Liu, Xiaojing; Zhang, Xiaofu; Huang, Anping; Xiao, Zhisong; Fang, Jiancheng

    2018-01-01

    Anomalous dispersion enhancement physical mechanism for Sagnac effect is described by special relativity derivation, and three kinds of definitions of minimum detectable angular rate of resonance optical gyroscope (ROG) are compared and the relations among them are investigated. The effect of linewidth broadening induced by anomalous dispersion on the sensitivity of ROG is discussed in this paper. Material dispersion-broadened resonance linewidth deteriorates the performance of a passive ROG and dispersion enhancement effect, while the sensitivity of a structural dispersion ROG is enhanced by two orders of magnitude even considering the dispersion-broadened resonance linewidth.

  9. Uncertainty of angular displacement measurement with a MEMS gyroscope integrated in a smartphone

    International Nuclear Information System (INIS)

    De Campos Porath, Maurício; Dolci, Ricardo

    2015-01-01

    Low-cost inertial sensors have recently gained popularity and are now widely used in electronic devices such as smartphones and tablets. In this paper we present the results of a set of experiments aiming to assess the angular displacement measurement errors of a gyroscope integrated in a smartphone of a recent model. The goal is to verify whether these sensors could substitute dedicated electronic inclinometers for the measurement of angular displacement. We estimated a maximum error of 0.3° (sum of expanded uncertainty and maximum absolute bias) for the roll and pitch axes, for a measurement time without referencing up to 1 h. (paper)

  10. Interactive modeling activities in the classroom—rotational motion and smartphone gyroscopes

    Science.gov (United States)

    Pörn, Ray; Braskén, Mats

    2016-11-01

    The wide-spread availability of smartphones makes them a valuable addition to the measurement equipment in both the physics classroom and the instructional laboratory, encouraging an active interaction between measurements and modeling activities. In this paper we illustrate this interaction by making use of the internal gyroscope of a smartphone to study and measure the rotational dynamics of objects rotating about a fixed axis. The workflow described in this paper has been tested in a classroom setting and found to encourage an exploratory approach to both data collecting and modeling.

  11. Minimal-Learning-Parameter Technique Based Adaptive Neural Sliding Mode Control of MEMS Gyroscope

    Directory of Open Access Journals (Sweden)

    Bin Xu

    2017-01-01

    Full Text Available This paper investigates an adaptive neural sliding mode controller for MEMS gyroscopes with minimal-learning-parameter technique. Considering the system uncertainty in dynamics, neural network is employed for approximation. Minimal-learning-parameter technique is constructed to decrease the number of update parameters, and in this way the computation burden is greatly reduced. Sliding mode control is designed to cancel the effect of time-varying disturbance. The closed-loop stability analysis is established via Lyapunov approach. Simulation results are presented to demonstrate the effectiveness of the method.

  12. Establishment and analysis of coupled dynamic model for dual-mass silicon micro-gyroscope

    Science.gov (United States)

    Wang, Zhanghui; Qiu, Anping; Shi, Qin; Zhang, Taoyuan

    2017-12-01

    This paper presents a coupled dynamic model for a dual-mass silicon micro-gyroscope (DMSG). It can quantitatively analyze the influence of left-right stiffness difference on the natural frequencies, modal matrix and modal coupling coefficient of the DMSG. The analytic results are verified by using the finite element method (FEM) simulation. The model shows that with the left-right stiffness difference of 1%, the modal coupling coefficient is 12% in the driving direction and 31% in the sensing direction. It also shows that in order to achieve good separation, the stiffness of base beam should be small enough in both the driving and sensing direction.

  13. Efficiency of a gyroscopic device for conversion of mechanical wave energy to electrical energy

    DEFF Research Database (Denmark)

    Carlsen, Martin; Darula, Radoslav; Gravesen, Jens

    2011-01-01

    We consider a recently proposed gyroscopic device for conversion of mechanical ocean wave energy to electrical energy. Two models of the device derived from standard engineering mechanics from the literature are analysed, and a model is derived from analytical mechanics considerations. From...... these models, estimates of the power production, eciency, forces and moments are made. We nd that it is possible to extract a signicant amount of energy from an ocean wave using the described device. Further studies are required for a full treatment of the device....

  14. A novel Cs-(129)Xe atomic spin gyroscope with closed-loop Faraday modulation.

    Science.gov (United States)

    Fang, Jiancheng; Wan, Shuangai; Qin, Jie; Zhang, Chen; Quan, Wei; Yuan, Heng; Dong, Haifeng

    2013-08-01

    We report a novel Cs-(129)Xe atomic spin gyroscope (ASG) with closed-loop Faraday modulation method. This ASG requires approximately 30 min to start-up and 110 °C to operate. A closed-loop Faraday modulation method for measurement of the optical rotation was used in this ASG. This method uses an additional Faraday modulator to suppress the laser intensity fluctuation and Faraday modulator thermal induced fluctuation. We theoretically and experimentally validate this method in the Cs-(129)Xe ASG and achieved a bias stability of approximately 3.25 °∕h.

  15. The influence of nonideal factors on the capacitance permittivity in a liquid-suspended rotor micro-gyroscope

    Directory of Open Access Journals (Sweden)

    Ming-Yuan Ren

    2014-03-01

    Full Text Available The nonideal factors of a liquid-suspended rotor micro-gyroscope include the gas-liquid two-phase flow voids, medium temperature and its dielectric relaxation, in which the role of the nonideal factors on the capacitor dielectric constant is altered, thereby affecting the capacitance detection precision of the micro-gyroscope. By comparing four different liquid media, the experimental results reveal the nonideal character of the capacitor dielectric constant. The 7# white oil is suitable for use as the liquid-suspended gyro cavity liquid medium.

  16. How Angular Velocity Features and Different Gyroscope Noise Types Interact and Determine Orientation Estimation Accuracy

    Science.gov (United States)

    Pasciuto, Ilaria; Ligorio, Gabriele; Bergamini, Elena; Vannozzi, Giuseppe; Sabatini, Angelo Maria; Cappozzo, Aurelio

    2015-01-01

    In human movement analysis, 3D body segment orientation can be obtained through the numerical integration of gyroscope signals. These signals, however, are affected by errors that, for the case of micro-electro-mechanical systems, are mainly due to: constant bias, scale factor, white noise, and bias instability. The aim of this study is to assess how the orientation estimation accuracy is affected by each of these disturbances, and whether it is influenced by the angular velocity magnitude and 3D distribution across the gyroscope axes. Reference angular velocity signals, either constant or representative of human walking, were corrupted with each of the four noise types within a simulation framework. The magnitude of the angular velocity affected the error in the orientation estimation due to each noise type, except for the white noise. Additionally, the error caused by the constant bias was also influenced by the angular velocity 3D distribution. As the orientation error depends not only on the noise itself but also on the signal it is applied to, different sensor placements could enhance or mitigate the error due to each disturbance, and special attention must be paid in providing and interpreting measures of accuracy for orientation estimation algorithms. PMID:26393606

  17. PENGENDALIAN PID PADA ROBOT MIROSOT UPN “VETERAN” YOGYAKARTA BERBASIS SENSOR GYROSCOPE DAN ACCELEROMETER

    Directory of Open Access Journals (Sweden)

    Awang Hendrianto Pratomo

    2015-07-01

    Full Text Available MiRoSoT Robot movement is influenced by the speed control from right and left wheels. Wheels speed control on MiroSot robot is determined by parameter PID (Proportional Integral and Derevative value. PID value determined by robot position and angle. MiroSot robot movement is still not stable and can not move in accordance with the instruction have been made. Instability of the robot movement in the game is affected by friction wheels against the ground, friction gear and robot load. In this study, implemented a gyroscope and accelerometer sensors to stabilize robot movement. Based on both sensors are controlled by using a microcontroller ATmega64. Speed control system based on gyroscope and accelerometer sensor is obtained that the robot is able to face a certain angle more precisely. The accelerometer sensor is used as a parameter for the braking system, so the robot is able to move more stable without the loss of power from the motor during a reduction speed from the strategy control.

  18. Using commodity accelerometers and gyroscopes to improve speed and accuracy of JanusVF

    Science.gov (United States)

    Hutson, Malcolm; Reiners, Dirk

    2010-01-01

    Several critical limitations exist in the currently available commercial tracking technologies for fully-enclosed virtual reality (VR) systems. While several 6DOF solutions can be adapted to work in fully-enclosed spaces, they still include elements of hardware that can interfere with the user's visual experience. JanusVF introduced a tracking solution for fully-enclosed VR displays that achieves comparable performance to available commercial solutions but without artifacts that can obscure the user's view. JanusVF employs a small, high-resolution camera that is worn on the user's head, but faces backwards. The VR rendering software draws specific fiducial markers with known size and absolute position inside the VR scene behind the user but in view of the camera. These fiducials are tracked by ARToolkitPlus and integrated by a single-constraint-at-a-time (SCAAT) filter to update the head pose. In this paper we investigate the addition of low-cost accelerometers and gyroscopes such as those in Nintendo Wii remotes, the Wii Motion Plus, and the Sony Sixaxis controller to improve the precision and accuracy of JanusVF. Several enthusiast projects have implemented these units as basic trackers or for gesture recognition, but none so far have created true 6DOF trackers using only the accelerometers and gyroscopes. Our original experiments were repeated after adding the low-cost inertial sensors, showing considerable improvements and noise reduction.

  19. Markerless Augmented Reality Utilizing Gyroscope to Demonstrate the Position of Dewata Nawa Sanga

    Directory of Open Access Journals (Sweden)

    I Wayan Andis Indrawan

    2018-01-01

    Full Text Available Dewata Nawa Sanga in Hinduism has an important role as the foundation of the religious concept implemented by Hindus in Bali, Indonesia. It has the meaning of nine deities or manifestations of Ida Sang Hyang Widhi Wasa (God Almighty  that guard or control the nine wind direction. Dewata Nawa Sanga in terms of education in Bali has been learned by the elementary school students. However, in social life the concept of Dewata Nawa Sanga itself has not been attached and understood by all Balinese Hinduism yet. Based on the problem in social life, there is an idea to develop Markerless Augmented Reality Utilizing Gyroscope to Demonstrate the Position of Dewata Nawa Sanga. This application is designed to know, recognize, and understand the characteristics of Dewata Nawa Sanga using gyroscope. This sensor serves to fulfill the object of the deities in the coordinates to be determined. Furthermore, it serves to provide information about Dewata Nawa Sanga along with the innovative and informative 3D animation. The result of usefulness questionnaire of this application percentage value average is 88.4%. It can be concluded that AR Dewata Nawa Sanga is very useful and helpful for learners in exploring the Dewata Nawa Sanga position in a real-world environment. The result of usability and satisfaction questionnaire of this application percentage value average is 84.8%. It shows that the application is very useful for the participants to learn Dewata Nawa Sanga and very satisfied to use.

  20. Error Correction of Measured Unstructured Road Profiles Based on Accelerometer and Gyroscope Data

    Directory of Open Access Journals (Sweden)

    Jinhua Han

    2017-01-01

    Full Text Available This paper describes a noncontact acquisition system composed of several time synchronized laser height sensors, accelerometers, gyroscope, and so forth in order to collect the road profiles of vehicle riding on the unstructured roads. A method of correcting road profiles based on the accelerometer and gyroscope data is proposed to eliminate the adverse impacts of vehicle vibration and attitudes change. Because the power spectral density (PSD of gyro attitudes concentrates in the low frequency band, a method called frequency division is presented to divide the road profiles into two parts: high frequency part and low frequency part. The vibration error of road profiles is corrected by displacement data obtained through two times integration of measured acceleration data. After building the mathematical model between gyro attitudes and road profiles, the gyro attitudes signals are separated from low frequency road profile by the method of sliding block overlap based on correlation analysis. The accuracy and limitations of the system have been analyzed, and its validity has been verified by implementing the system on wheeled equipment for road profiles’ measuring of vehicle testing ground. The paper offers an accurate and practical approach to obtaining unstructured road profiles for road simulation test.

  1. How Angular Velocity Features and Different Gyroscope Noise Types Interact and Determine Orientation Estimation Accuracy.

    Science.gov (United States)

    Pasciuto, Ilaria; Ligorio, Gabriele; Bergamini, Elena; Vannozzi, Giuseppe; Sabatini, Angelo Maria; Cappozzo, Aurelio

    2015-09-18

    In human movement analysis, 3D body segment orientation can be obtained through the numerical integration of gyroscope signals. These signals, however, are affected by errors that, for the case of micro-electro-mechanical systems, are mainly due to: constant bias, scale factor, white noise, and bias instability. The aim of this study is to assess how the orientation estimation accuracy is affected by each of these disturbances, and whether it is influenced by the angular velocity magnitude and 3D distribution across the gyroscope axes. Reference angular velocity signals, either constant or representative of human walking, were corrupted with each of the four noise types within a simulation framework. The magnitude of the angular velocity affected the error in the orientation estimation due to each noise type, except for the white noise. Additionally, the error caused by the constant bias was also influenced by the angular velocity 3D distribution. As the orientation error depends not only on the noise itself but also on the signal it is applied to, different sensor placements could enhance or mitigate the error due to each disturbance, and special attention must be paid in providing and interpreting measures of accuracy for orientation estimation algorithms.

  2. Modeling and Implementation of Multi-Position Non-Continuous Rotation Gyroscope North Finder

    Directory of Open Access Journals (Sweden)

    Jun Luo

    2016-09-01

    Full Text Available Even when the Global Positioning System (GPS signal is blocked, a rate gyroscope (gyro north finder is capable of providing the required azimuth reference information to a certain extent. In order to measure the azimuth between the observer and the north direction very accurately, we propose a multi-position non-continuous rotation gyro north finding scheme. Our new generalized mathematical model analyzes the elements that affect the azimuth measurement precision and can thus provide high precision azimuth reference information. Based on the gyro’s principle of detecting a projection of the earth rotation rate on its sensitive axis and the proposed north finding scheme, we are able to deduct an accurate mathematical model of the gyro outputs against azimuth with the gyro and shaft misalignments. Combining the gyro outputs model and the theory of propagation of uncertainty, some approaches to optimize north finding are provided, including reducing the gyro bias error, constraining the gyro random error, increasing the number of rotation points, improving rotation angle measurement precision, decreasing the gyro and the shaft misalignment angles. According them, a north finder setup is built and the azimuth uncertainty of 18” is obtained. This paper provides systematic theory for analyzing the details of the gyro north finder scheme from simulation to implementation. The proposed theory can guide both applied researchers in academia and advanced practitioners in industry for designing high precision robust north finder based on different types of rate gyroscopes.

  3. How Angular Velocity Features and Different Gyroscope Noise Types Interact and Determine Orientation Estimation Accuracy

    Directory of Open Access Journals (Sweden)

    Ilaria Pasciuto

    2015-09-01

    Full Text Available In human movement analysis, 3D body segment orientation can be obtained through the numerical integration of gyroscope signals. These signals, however, are affected by errors that, for the case of micro-electro-mechanical systems, are mainly due to: constant bias, scale factor, white noise, and bias instability. The aim of this study is to assess how the orientation estimation accuracy is affected by each of these disturbances, and whether it is influenced by the angular velocity magnitude and 3D distribution across the gyroscope axes. Reference angular velocity signals, either constant or representative of human walking, were corrupted with each of the four noise types within a simulation framework. The magnitude of the angular velocity affected the error in the orientation estimation due to each noise type, except for the white noise. Additionally, the error caused by the constant bias was also influenced by the angular velocity 3D distribution. As the orientation error depends not only on the noise itself but also on the signal it is applied to, different sensor placements could enhance or mitigate the error due to each disturbance, and special attention must be paid in providing and interpreting measures of accuracy for orientation estimation algorithms.

  4. Use of Earth's magnetic field for mitigating gyroscope errors regardless of magnetic perturbation.

    Science.gov (United States)

    Afzal, Muhammad Haris; Renaudin, Valérie; Lachapelle, Gérard

    2011-01-01

    Most portable systems like smart-phones are equipped with low cost consumer grade sensors, making them useful as Pedestrian Navigation Systems (PNS). Measurements of these sensors are severely contaminated by errors caused due to instrumentation and environmental issues rendering the unaided navigation solution with these sensors of limited use. The overall navigation error budget associated with pedestrian navigation can be categorized into position/displacement errors and attitude/orientation errors. Most of the research is conducted for tackling and reducing the displacement errors, which either utilize Pedestrian Dead Reckoning (PDR) or special constraints like Zero velocity UPdaTes (ZUPT) and Zero Angular Rate Updates (ZARU). This article targets the orientation/attitude errors encountered in pedestrian navigation and develops a novel sensor fusion technique to utilize the Earth's magnetic field, even perturbed, for attitude and rate gyroscope error estimation in pedestrian navigation environments where it is assumed that Global Navigation Satellite System (GNSS) navigation is denied. As the Earth's magnetic field undergoes severe degradations in pedestrian navigation environments, a novel Quasi-Static magnetic Field (QSF) based attitude and angular rate error estimation technique is developed to effectively use magnetic measurements in highly perturbed environments. The QSF scheme is then used for generating the desired measurements for the proposed Extended Kalman Filter (EKF) based attitude estimator. Results indicate that the QSF measurements are capable of effectively estimating attitude and gyroscope errors, reducing the overall navigation error budget by over 80% in urban canyon environment.

  5. Optimization of an Accelerometer and Gyroscope-Based Fall Detection Algorithm

    Directory of Open Access Journals (Sweden)

    Quoc T. Huynh

    2015-01-01

    Full Text Available Falling is a common and significant cause of injury in elderly adults (>65 yrs old, often leading to disability and death. In the USA, one in three of the elderly suffers from fall injuries annually. This study’s purpose is to develop, optimize, and assess the efficacy of a falls detection algorithm based upon a wireless, wearable sensor system (WSS comprised of a 3-axis accelerometer and gyroscope. For this study, the WSS is placed at the chest center to collect real-time motion data of various simulated daily activities (i.e., walking, running, stepping, and falling. Tests were conducted on 36 human subjects with a total of 702 different movements collected in a laboratory setting. Half of the dataset was used for development of the fall detection algorithm including investigations of critical sensor thresholds and the remaining dataset was used for assessment of algorithm sensitivity and specificity. Experimental results show that the algorithm detects falls compared to other daily movements with a sensitivity and specificity of 96.3% and 96.2%, respectively. The addition of gyroscope information enhances sensitivity dramatically from results in the literature as angular velocity changes provide further delineation of a fall event from other activities that may also experience high acceleration peaks.

  6. Self-induced parametric amplification arising from nonlinear elastic coupling in a micromechanical resonating disk gyroscope.

    Science.gov (United States)

    Nitzan, Sarah H; Zega, Valentina; Li, Mo; Ahn, Chae H; Corigliano, Alberto; Kenny, Thomas W; Horsley, David A

    2015-03-12

    Parametric amplification, resulting from intentionally varying a parameter in a resonator at twice its resonant frequency, has been successfully employed to increase the sensitivity of many micro- and nano-scale sensors. Here, we introduce the concept of self-induced parametric amplification, which arises naturally from nonlinear elastic coupling between the degenerate vibration modes in a micromechanical disk-resonator, and is not externally applied. The device functions as a gyroscope wherein angular rotation is detected from Coriolis coupling of elastic vibration energy from a driven vibration mode into a second degenerate sensing mode. While nonlinear elasticity in silicon resonators is extremely weak, in this high quality-factor device, ppm-level nonlinear elastic effects result in an order-of-magnitude increase in the observed sensitivity to Coriolis force relative to linear theory. Perfect degeneracy of the primary and secondary vibration modes is achieved through electrostatic frequency tuning, which also enables the phase and frequency of the parametric coupling to be varied, and we show that the resulting phase and frequency dependence of the amplification follow the theory of parametric resonance. We expect that this phenomenon will be useful for both fundamental studies of dynamic systems with low dissipation and for increasing signal-to-noise ratio in practical applications such as gyroscopes.

  7. Vibration properties of a rotating piezoelectric energy harvesting device that experiences gyroscopic effects

    Science.gov (United States)

    Lu, Haohui; Chai, Tan; Cooley, Christopher G.

    2018-03-01

    This study investigates the vibration of a rotating piezoelectric device that consists of a proof mass that is supported by elastic structures with piezoelectric layers. Vibration of the proof mass causes deformation in the piezoelectric structures and voltages to power the electrical loads. The coupled electromechanical equations of motion are derived using Newtonian mechanics and Kirchhoff's circuit laws. The free vibration behavior is investigated for devices with identical (tuned) and nonidentical (mistuned) piezoelectric support structures and electrical loads. These devices have complex-valued, speed-dependent eigenvalues and eigenvectors as a result of gyroscopic effects caused by their constant rotation. The characteristics of the complex-valued eigensolutions are related to physical behavior of the device's vibration. The free vibration behaviors differ significantly for tuned and mistuned devices. Due to gyroscopic effects, the proof mass in the tuned device vibrates in either forward or backward decaying circular orbits in single-mode free response. This is proven analytically for all tuned devices, regardless of the device's specific parameters or operating speed. For mistuned devices, the proof mass has decaying elliptical forward and backward orbits. The eigenvalues are shown to be sensitive to changes in the electrical load resistances. Closed-form solutions for the eigenvalues are derived for open and close circuits. At high rotation speeds these devices experience critical speeds and instability.

  8. Observability analysis of a MEMS INS/GPS integration system with gyroscope G-sensitivity errors.

    Science.gov (United States)

    Fan, Chen; Hu, Xiaoping; He, Xiaofeng; Tang, Kanghua; Luo, Bing

    2014-08-28

    Gyroscopes based on micro-electromechanical system (MEMS) technology suffer in high-dynamic applications due to obvious g-sensitivity errors. These errors can induce large biases in the gyroscope, which can directly affect the accuracy of attitude estimation in the integration of the inertial navigation system (INS) and the Global Positioning System (GPS). The observability determines the existence of solutions for compensating them. In this paper, we investigate the observability of the INS/GPS system with consideration of the g-sensitivity errors. In terms of two types of g-sensitivity coefficients matrix, we add them as estimated states to the Kalman filter and analyze the observability of three or nine elements of the coefficient matrix respectively. A global observable condition of the system is presented and validated. Experimental results indicate that all the estimated states, which include position, velocity, attitude, gyro and accelerometer bias, and g-sensitivity coefficients, could be made observable by maneuvering based on the conditions. Compared with the integration system without compensation for the g-sensitivity errors, the attitude accuracy is raised obviously.

  9. Observability Analysis of a MEMS INS/GPS Integration System with Gyroscope G-Sensitivity Errors

    Directory of Open Access Journals (Sweden)

    Chen Fan

    2014-08-01

    Full Text Available Gyroscopes based on micro-electromechanical system (MEMS technology suffer in high-dynamic applications due to obvious g-sensitivity errors. These errors can induce large biases in the gyroscope, which can directly affect the accuracy of attitude estimation in the integration of the inertial navigation system (INS and the Global Positioning System (GPS. The observability determines the existence of solutions for compensating them. In this paper, we investigate the observability of the INS/GPS system with consideration of the g-sensitivity errors. In terms of two types of g-sensitivity coefficients matrix, we add them as estimated states to the Kalman filter and analyze the observability of three or nine elements of the coefficient matrix respectively. A global observable condition of the system is presented and validated. Experimental results indicate that all the estimated states, which include position, velocity, attitude, gyro and accelerometer bias, and g-sensitivity coefficients, could be made observable by maneuvering based on the conditions. Compared with the integration system without compensation for the g-sensitivity errors, the attitude accuracy is raised obviously.

  10. A Lever Coupling Mechanism in Dual-Mass Micro-Gyroscopes for Improving the Shock Resistance along the Driving Direction

    Directory of Open Access Journals (Sweden)

    Yang Gao

    2017-04-01

    Full Text Available This paper presents the design and application of a lever coupling mechanism to improve the shock resistance of a dual-mass silicon micro-gyroscope with drive mode coupled along the driving direction without sacrificing the mechanical sensitivity. Firstly, the mechanical sensitivity and the shock response of the micro-gyroscope are theoretically analyzed. In the mechanical design, a novel lever coupling mechanism is proposed to change the modal order and to improve the frequency separation. The micro-gyroscope with the lever coupling mechanism optimizes the drive mode order, increasing the in-phase mode frequency to be much larger than the anti-phase one. Shock analysis results show that the micro-gyroscope structure with the designed lever coupling mechanism can notably reduce the magnitudes of the shock response and cut down the stress produced in the shock process compared with the traditional elastic coupled one. Simulations reveal that the shock resistance along the drive direction is greatly increased. Consequently, the lever coupling mechanism can change the gyroscope’s modal order and improve the frequency separation by structurally offering a higher stiffness difference ratio. The shock resistance along the driving direction is tremendously enhanced without loss of the mechanical sensitivity.

  11. Modeling and Compensation of Random Drift of MEMS Gyroscopes Based on Least Squares Support Vector Machine Optimized by Chaotic Particle Swarm Optimization.

    Science.gov (United States)

    Xing, Haifeng; Hou, Bo; Lin, Zhihui; Guo, Meifeng

    2017-10-13

    MEMS (Micro Electro Mechanical System) gyroscopes have been widely applied to various fields, but MEMS gyroscope random drift has nonlinear and non-stationary characteristics. It has attracted much attention to model and compensate the random drift because it can improve the precision of inertial devices. This paper has proposed to use wavelet filtering to reduce noise in the original data of MEMS gyroscopes, then reconstruct the random drift data with PSR (phase space reconstruction), and establish the model for the reconstructed data by LSSVM (least squares support vector machine), of which the parameters were optimized using CPSO (chaotic particle swarm optimization). Comparing the effect of modeling the MEMS gyroscope random drift with BP-ANN (back propagation artificial neural network) and the proposed method, the results showed that the latter had a better prediction accuracy. Using the compensation of three groups of MEMS gyroscope random drift data, the standard deviation of three groups of experimental data dropped from 0.00354°/s, 0.00412°/s, and 0.00328°/s to 0.00065°/s, 0.00072°/s and 0.00061°/s, respectively, which demonstrated that the proposed method can reduce the influence of MEMS gyroscope random drift and verified the effectiveness of this method for modeling MEMS gyroscope random drift.

  12. Investigation of a geodesy coexperiment to the Gravity Probe B relativity gyroscope program

    Science.gov (United States)

    Everitt, C. W. F.; Parkinson, Bradford W.; Tapley, Mark

    1993-01-01

    Geodesy is the science of measuring the gravitational field of and positions on the Earth. Estimation of the gravitational field via gravitation gradiometry, the measurement of variations in the direction and magnitude of gravitation with respect to position, is this dissertation's focus. Gravity Probe B (GP-B) is a Stanford satellite experiment in gravitational physics. GP-B will measure the precession the rotating Earth causes on the space time around it by observing the precessions of four gyroscopes in a circular, polar, drag-free orbit at 650 km altitude. The gyroscopes are nearly perfect niobium-coated spheres of quartz, operating at 1.8 K to permit observations with extremely low thermal noise. The permissible gyroscope drift rate is miniscule, so the torques on the gyros must be tiny. A drag-free control system, by canceling accelerations caused by nongravitational forces, minimizes the support forces and hence torques. The GP-B system offers two main possibilities for geodesy. One is as a drag-free satellite to be used in trajectory-based estimates of the Earth's gravity field. We described calculations involving that approach in our previous reports, including comparison of laser only, GPS only, and combined tracking and a preliminary estimate of the possibility of estimating relativistic effects on the orbit. The second possibility is gradiometry. This technique has received a more cursory examination in previous reports, so we concentrate on it here. We explore the feasibility of using the residual suspension forces centering the GP-B gyros as gradiometer signals for geodesy. The objective of this work is a statistical prediction of the formal uncertainty in an estimate of the Earth's gravitation field using data from GP-B. We perform an instrument analysis and apply two mathematical techniques to predict uncertainty. One is an analytical approach using a flat-Earth approximation to predict geopotential information quality as a function of spatial

  13. Chaos control and generalized projective synchronization of heavy symmetric chaotic gyroscope systems via Gaussian radial basis adaptive variable structure control

    International Nuclear Information System (INIS)

    Farivar, Faezeh; Aliyari Shoorehdeli, Mahdi; Nekoui, Mohammad Ali; Teshnehlab, Mohammad

    2012-01-01

    Highlights: ► A systematic procedure for GPS of unknown heavy chaotic gyroscope systems. ► Proposed methods are based on Lyapunov stability theory. ► Without calculating Lyapunov exponents and Eigen values of the Jacobian matrix. ► Capable to extend for a variety of chaotic systems. ► Useful for practical applications in the future. - Abstract: This paper proposes the chaos control and the generalized projective synchronization methods for heavy symmetric gyroscope systems via Gaussian radial basis adaptive variable structure control. Because of the nonlinear terms of the gyroscope system, the system exhibits chaotic motions. Occasionally, the extreme sensitivity to initial states in a system operating in chaotic mode can be very destructive to the system because of unpredictable behavior. In order to improve the performance of a dynamic system or avoid the chaotic phenomena, it is necessary to control a chaotic system with a periodic motion beneficial for working with a particular condition. As chaotic signals are usually broadband and noise like, synchronized chaotic systems can be used as cipher generators for secure communication. This paper presents chaos synchronization of two identical chaotic motions of symmetric gyroscopes. In this paper, the switching surfaces are adopted to ensure the stability of the error dynamics in variable structure control. Using the neural variable structure control technique, control laws are established which guarantees the chaos control and the generalized projective synchronization of unknown gyroscope systems. In the neural variable structure control, Gaussian radial basis functions are utilized to on-line estimate the system dynamic functions. Also, the adaptation laws of the on-line estimator are derived in the sense of Lyapunov function. Thus, the unknown gyro systems can be guaranteed to be asymptotically stable. Also, the proposed method can achieve the control objectives. Numerical simulations are presented to

  14. Adaptive Sliding Mode Control of MEMS Gyroscope Based on Neural Network Approximation

    Directory of Open Access Journals (Sweden)

    Yuzheng Yang

    2014-01-01

    Full Text Available An adaptive sliding controller using radial basis function (RBF network to approximate the unknown system dynamics microelectromechanical systems (MEMS gyroscope sensor is proposed. Neural controller is proposed to approximate the unknown system model and sliding controller is employed to eliminate the approximation error and attenuate the model uncertainties and external disturbances. Online neural network (NN weight tuning algorithms, including correction terms, are designed based on Lyapunov stability theory, which can guarantee bounded tracking errors as well as bounded NN weights. The tracking error bound can be made arbitrarily small by increasing a certain feedback gain. Numerical simulation for a MEMS angular velocity sensor is investigated to verify the effectiveness of the proposed adaptive neural control scheme and demonstrate the satisfactory tracking performance and robustness.

  15. Anisotropic kinetic energy release and gyroscopic behavior of CO2 super rotors from an optical centrifuge

    Science.gov (United States)

    Murray, Matthew J.; Ogden, Hannah M.; Mullin, Amy S.

    2017-10-01

    An optical centrifuge is used to generate an ensemble of CO2 super rotors with oriented angular momentum. The collision dynamics and energy transfer behavior of the super rotor molecules are investigated using high-resolution transient IR absorption spectroscopy. New multipass IR detection provides improved sensitivity to perform polarization-dependent transient studies for rotational states with 76 ≤ J ≤ 100. Polarization-dependent measurements show that the collision-induced kinetic energy release is spatially anisotropic and results from both near-resonant energy transfer between super rotor molecules and non-resonant energy transfer between super rotors and thermal molecules. J-dependent studies show that the extent and duration of the orientational anisotropy increase with rotational angular momentum. The super rotors exhibit behavior akin to molecular gyroscopes, wherein molecules with larger amounts of angular momentum are less likely to change their angular momentum orientation through collisions.

  16. A complete solution for GP-B's gyroscopic precession by retarded gravitational theory

    Science.gov (United States)

    Tang, Keyun

    Mainstream physicists generally believe that Mercury’s Perihelion precession and GP-B’ gyroscopic precession are two of the strongest evidences supporting Einstein’ curved spacetime and general relativity. However, most classical literatures and textbooks (e.g. Ohanain: Gravitation and Spacetime) paint an incorrect picture of Mercury’s orbit anomaly, namely Mercury’s perihelion precessed 43 arc-seconds per century; a correct picture should be that Mercury rotated 43 arc-seconds per century more than along Newtonian theoretical orbit. The essence of Le Verrier’s and Newcomb’s observation and analysis is that the angular speed of Mercury is slightly faster than the Newtonian theoretical value. The complete explanation to Mercury’s orbit anomaly should include two factors, perihelion precession is one of two factors, in addition, the change of orbital radius will also cause a change of angular speed, which is another component of Mercury's orbital anomaly. If Schwarzschild metric is correct, then the solution of the Schwarzschild orbit equation must contain three non-ignorable items. The first corresponds to Newtonian ellipse; the second is a nonlinear perturbation with increasing amplitude, which causes the precession of orbit perihelion; this is just one part of the angular speed anomaly of Mercury; the third part is a linear perturbation, corresponding to a similar figure of the Newton's ellipse, but with a minimal radius; this makes no contribution to the perihelion precession of the Schwarzschild orbit, but makes the Schwarzschild orbital radius slightly smaller, leading to a slight increase in Mercury’s angular speed. All classical literatures of general relativity ignored this last factor, which is a gross oversight. If you correctly take all three factors into consideration, the final result is that the difference between the angles rotated along Schwarzschild’s orbit and the angle rotated along Newton’s orbit for one hundred years should

  17. Modified Cross Feedback Control for a Magnetically Suspended Flywheel Rotor with Significant Gyroscopic Effects

    Directory of Open Access Journals (Sweden)

    Yuan Ren

    2014-01-01

    Full Text Available For magnetically suspended rigid rotors (MSRs with significant gyroscopic effects, phase lag of the control channel is the main factor influencing the system nutation stability and decoupling performance. At first, this paper proves that the phase lag of the cross channel instead of the decentralized channel is often the main factor influencing the system nutation stability at high speeds. Then a modified cross feedback control strategy based on the phase compensation of cross channel is proposed to improve the stability and decoupling performances. The common issues associated with the traditional control methods have been successfully resolved by this method. Analysis, simulation, and experimental results are presented to demonstrate the feasibility and superiority of the proposed control method.

  18. Vernier effect-based multiplication of the Sagnac beating frequency in ring laser gyroscope sensors

    Science.gov (United States)

    Adib, George A.; Sabry, Yasser M.; Khalil, Diaa

    2018-02-01

    A multiplication method of the Sagnac effect scale factor in ring laser gyroscopes is presented based on the Vernier effect of a dual-coupler passive ring resonator coupled to the active ring. The multiplication occurs when the two rings have comparable lengths or integer multiples and their scale factors have opposite signs. In this case, and when the rings have similar areas, the scale factor is multiplied by ratio of their length to their length difference. The scale factor of the presented configuration is derived analytically and the lock-in effect is analyzed. The principle is demonstrated using optical fiber rings and semiconductor optical amplifier as gain medium. A scale factor multiplication by about 175 is experimentally measured, demonstrating larger than two orders of magnitude enhancement in the Sagnac effect scale factor for the first time in literature, up to the authors' knowledge.

  19. Effects of Polarization–Maintaining Fibre Degrading on Precision of Fibre Optic Gyroscopes in Radiation Environment

    International Nuclear Information System (INIS)

    Wen, Xiao; De-Wen, Liu; Yang, Liu; Xiao-Su, Yi; Lin, Cong

    2008-01-01

    In the space environment, the precision of fibre optic gyroscopes (FOGs) degrades because of space radiation. Photonic components of FOGs are affected by radiation, especially the polarization-maintaining (PM) fibre coil. In relation to the space radiation environment characteristic, we have carried out a series of radiation experiments on a PM fibre coil with 60 Co radiation source at different dose rates. Based on the experimental results, the formula between the PM-fibre loss and radiation dose rate is built, and the relation between the precision of FOG and radiation dose is obtained accordingly. The results strongly show that the precision of our FOG degrades owing to the attenuation of the polarization-maintaining fibre, which provides theoretical foundation for the radiation-resistant design of the FOG

  20. A Statistical Parameter Analysis and SVM Based Fault Diagnosis Strategy for Dynamically Tuned Gyroscopes

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Gyro's fault diagnosis plays a critical role in inertia navigation systems for higher reliability and precision. A new fault diagnosis strategy based on the statistical parameter analysis (SPA) and support vector machine(SVM) classification model was proposed for dynamically tuned gyroscopes (DTG). The SPA, a kind of time domain analysis approach, was introduced to compute a set of statistical parameters of vibration signal as the state features of DTG, with which the SVM model, a novel learning machine based on statistical learning theory (SLT), was applied and constructed to train and identify the working state of DTG. The experimental results verify that the proposed diagnostic strategy can simply and effectively extract the state features of DTG, and it outperforms the radial-basis function (RBF) neural network based diagnostic method and can more reliably and accurately diagnose the working state of DTG.

  1. Temperature Dependence of Faraday Effect-Induced Bias Error in a Fiber Optic Gyroscope.

    Science.gov (United States)

    Li, Xuyou; Liu, Pan; Guang, Xingxing; Xu, Zhenlong; Guan, Lianwu; Li, Guangchun

    2017-09-07

    Improving the performance of interferometric fiber optic gyroscope (IFOG) in harsh environments, such as magnetic field and temperature field variation, is necessary for its practical applications. This paper presents an investigation of Faraday effect-induced bias error of IFOG under varying temperature. Jones matrix method is utilized to formulize the temperature dependence of Faraday effect-induced bias error. Theoretical results show that the Faraday effect-induced bias error changes with the temperature in the non-skeleton polarization maintaining (PM) fiber coil. This phenomenon is caused by the temperature dependence of linear birefringence and Verdet constant of PM fiber. Particularly, Faraday effect-induced bias errors of two polarizations always have opposite signs that can be compensated optically regardless of the changes of the temperature. Two experiments with a 1000 m non-skeleton PM fiber coil are performed, and the experimental results support these theoretical predictions. This study is promising for improving the bias stability of IFOG.

  2. A Novel Temperature Compensation Method for a MEMS Gyroscope Oriented on a Periphery Circuit

    Directory of Open Access Journals (Sweden)

    Huiliang Cao

    2013-09-01

    Full Text Available This paper investigates temperature compensation methods used for the scale factor and bias of the MEMS gyroscope within the temperature range from − 40°C to 60°C. The structure and periphery monitor circuit are introduced. Then the determinant elements of the MEMS gyroscope's scale factor are analysed and the results indicate that scale factor is directly proportional to drive amplitude and sense loop gain and is inversely proportional to the frequency gap between two modes. After that, the compensation methods are proposed, the thermal resistor's positive temperature coefficient (tempco is utilized to calibrate the scale factor's tempco through regulating the drive mode amplitude and the sense loop gain, and each method is applied respectively and the results are contrasted. The test results of the two specimens express that the most effective compensation method could decrease the scale factor's tempco from 693ppm/°C (640ppm/°C to 250ppm/°C (257ppm/°C, improving it by 63.9% (59.8%. Finally, a method of declining bias's tempco is investigated and implemented after scale factor compensation. A summator with a thermal resistor is utilized at the output level and decreases the bias's tempco from 103.89°/h/°C (100.78°/h/°C to 9.70°/h/°C (12°/h/°C improving it by 90.7% (88%. Repeat tests are performed based on two specimens to prove the repeatability and reproducibility of the methods.

  3. Behavior of a test gyroscope moving towards a rotating traversable wormhole

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Chandrachur [Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, 400005 India (India); Pradhan, Parthapratim, E-mail: chandrachur.chakraborty@tifr.res.in, E-mail: pppradhan77@gmail.com [Department of Physics, Vivekananda Satabarshiki Mahavidyalaya, Manikpara, West Midnapur, 721513 India (India)

    2017-03-01

    The geodesic structure of the Teo wormhole is briefly discussed and some observables are derived that promise to be of use in detecting a rotating traversable wormhole indirectly, if it does exist. We also deduce the exact Lense-Thirring (LT) precession frequency of a test gyroscope moving toward a rotating traversable Teo wormhole. The precession frequency diverges on the ergoregion, a behavior intimately related to and governed by the geometry of the ergoregion, analogous to the situation in a Kerr spacetime. Interestingly, it turns out that here the LT precession is inversely proportional to the angular momentum ( a ) of the wormhole along the pole and around it in the strong gravity regime, a behavior contrasting with its direct variation with a in the case of other compact objects. In fact, divergence of LT precession inside the ergoregion can also be avoided if the gyro moves with a non-zero angular velocity in a certain range. As a result, the spin precession frequency of the gyro can be made finite throughout its whole path, even very close to the throat, during its travel to the wormhole. Furthermore, it is evident from our formulation that this spin precession not only arises due to curvature or rotation of the spacetime but also due to the non-zero angular velocity of the spin when it does not move along a geodesic in the strong gravity regime. If in the future, interstellar travel indeed becomes possible through a wormhole or at least in its vicinity, our results would prove useful in determining the behavior of a test gyroscope which is known to serve as a fundamental navigation device.

  4. Gyroscope-driven mouse pointer with an EMOTIV® EEG headset and data analysis based on Empirical Mode Decomposition.

    Science.gov (United States)

    Rosas-Cholula, Gerardo; Ramirez-Cortes, Juan Manuel; Alarcon-Aquino, Vicente; Gomez-Gil, Pilar; Rangel-Magdaleno, Jose de Jesus; Reyes-Garcia, Carlos

    2013-08-14

    This paper presents a project on the development of a cursor control emulating the typical operations of a computer-mouse, using gyroscope and eye-blinking electromyographic signals which are obtained through a commercial 16-electrode wireless headset, recently released by Emotiv. The cursor position is controlled using information from a gyroscope included in the headset. The clicks are generated through the user's blinking with an adequate detection procedure based on the spectral-like technique called Empirical Mode Decomposition (EMD). EMD is proposed as a simple and quick computational tool, yet effective, aimed to artifact reduction from head movements as well as a method to detect blinking signals for mouse control. Kalman filter is used as state estimator for mouse position control and jitter removal. The detection rate obtained in average was 94.9%. Experimental setup and some obtained results are presented.

  5. Gyroscope-Driven Mouse Pointer with an EMOTIV® EEG Headset and Data Analysis Based on Empirical Mode Decomposition

    Directory of Open Access Journals (Sweden)

    Carlos Reyes-Garcia

    2013-08-01

    Full Text Available This paper presents a project on the development of a cursor control emulating the typical operations of a computer-mouse, using gyroscope and eye-blinking electromyographic signals which are obtained through a commercial 16-electrode wireless headset, recently released by Emotiv. The cursor position is controlled using information from a gyroscope included in the headset. The clicks are generated through the user’s blinking with an adequate detection procedure based on the spectral-like technique called Empirical Mode Decomposition (EMD. EMD is proposed as a simple and quick computational tool, yet effective, aimed to artifact reduction from head movements as well as a method to detect blinking signals for mouse control. Kalman filter is used as state estimator for mouse position control and jitter removal. The detection rate obtained in average was 94.9%. Experimental setup and some obtained results are presented.

  6. Design, Construction, and Analysis of an Ultra-Low Expansion Quartz Resonant Cavity Passive Ring Resonator Laser Gyroscope.

    Science.gov (United States)

    1982-03-01

    Gyroscopes .... ....... 2 1.2 Sagnac’s Interferometer ....... ........ . . 4 1.3 Harress ’ Ring Interferometer ....... ...... 5 1.4 Michelson & Gale...graduate student, Harress , performed an experi- ment in which he attempted to measure the dispersion properties of glass. Figure 1.3 shows Harress ...8217 experiment. The results from his experiment did not agree-with data obtained from other methods, and Harress did not live long enough to find the discrepancy

  7. Complement the touch information given by the smartphone's capacitive screens with the information received by the accelerometer and gyroscope

    OpenAIRE

    Joaquim José Silva Faria Oliveira

    2014-01-01

    Currently it only is possible to obtain information about a tap on the smartphone's screen using the touch sensor. The goal of this project is to complement the information given by the smartphones touch screen with information given by the accelerometer and gyroscope and this way to extend the smartphone's touch capabilities with data such as tap strength, smartphone's holding position while taping (if it is on the users hands or laying on a hard surface) or which finger the touch was perfor...

  8. Gyroscopic sensing in the wings of the hawkmoth Manduca sexta: the role of sensor location and directional sensitivity.

    Science.gov (United States)

    Hinson, Brian T; Morgansen, Kristi A

    2015-10-06

    The wings of the hawkmoth Manduca sexta are lined with mechanoreceptors called campaniform sensilla that encode wing deformations. During flight, the wings deform in response to a variety of stimuli, including inertial-elastic loads due to the wing flapping motion, aerodynamic loads, and exogenous inertial loads transmitted by disturbances. Because the wings are actuated, flexible structures, the strain-sensitive campaniform sensilla are capable of detecting inertial rotations and accelerations, allowing the wings to serve not only as a primary actuator, but also as a gyroscopic sensor for flight control. We study the gyroscopic sensing of the hawkmoth wings from a control theoretic perspective. Through the development of a low-order model of flexible wing flapping dynamics, and the use of nonlinear observability analysis, we show that the rotational acceleration inherent in wing flapping enables the wings to serve as gyroscopic sensors. We compute a measure of sensor fitness as a function of sensor location and directional sensitivity by using the simulation-based empirical observability Gramian. Our results indicate that gyroscopic information is encoded primarily through shear strain due to wing twisting, where inertial rotations cause detectable changes in pronation and supination timing and magnitude. We solve an observability-based optimal sensor placement problem to find the optimal configuration of strain sensor locations and directional sensitivities for detecting inertial rotations. The optimal sensor configuration shows parallels to the campaniform sensilla found on hawkmoth wings, with clusters of sensors near the wing root and wing tip. The optimal spatial distribution of strain directional sensitivity provides a hypothesis for how heterogeneity of campaniform sensilla may be distributed.

  9. Novel Gyroscopic Mounting for Crystal Oscillators to Increase Short and Medium Term Stability under Highly Dynamic Conditions.

    Science.gov (United States)

    Abedi, Maryam; Jin, Tian; Sun, Kewen

    2015-06-17

    In this paper, a gyroscopic mounting method for crystal oscillators to reduce the impact of dynamic loads on their output stability has been proposed. In order to prove the efficiency of this mounting approach, each dynamic load-induced instability has been analyzed in detail. A statistical study has been performed on the elevation angle of the g-sensitivity vector of Stress Compensated-cut (SC-cut) crystals. The analysis results show that the proposed gyroscopic mounting method gives good performance for host vehicle attitude changes. A phase noise improvement of 27 dB maximum and 5.7 dB on average can be achieved in the case of steady state loads, while under sinusoidal vibration conditions, the maximum and average phase noise improvement are as high as 24 dB and 7.5 dB respectively. With this gyroscopic mounting method, random vibration-induced phase noise instability is reduced 30 dB maximum and 8.7 dB on average. Good effects are apparent for crystal g-sensitivity vectors with low elevation angle φ and azimuthal angle β. under highly dynamic conditions, indicating the probability that crystal oscillator instability will be significantly reduced by using the proposed mounting approach.

  10. From Gyroscopic to Thermal Motion: A Crossover in the Dynamics of Molecular Superrotors

    Science.gov (United States)

    Milner, A. A.; Korobenko, A.; Rezaiezadeh, K.; Milner, V.

    2015-07-01

    Localized heating of a gas by intense laser pulses leads to interesting acoustic, hydrodynamic, and optical effects with numerous applications in science and technology, including controlled wave guiding and remote atmosphere sensing. Rotational excitation of molecules can serve as the energy source for raising the gas temperature. Here, we study the dynamics of energy transfer from the molecular rotation to heat. By optically imaging a cloud of molecular superrotors, created with an optical centrifuge, we experimentally identify two separate and qualitatively different stages of its evolution. The first nonequilibrium "gyroscopic" stage is characterized by the modified optical properties of the centrifuged gas—its refractive index and optical birefringence, owing to the ultrafast directional molecular rotation, which survives tens of collisions. The loss of rotational directionality is found to overlap with the release of rotational energy to heat, which triggers the second stage of thermal expansion. The crossover between anisotropic rotational and isotropic thermal regimes is in agreement with recent theoretical predictions and our hydrodynamic calculations.

  11. The GINGERino ring laser gyroscope, seismological observations at one year from the first light

    Science.gov (United States)

    Simonelli, Andreino; Belfi, Jacopo; Beverini, Nicolò; Di Virgilio, Angela; Carelli, Giorgio; Maccioni, Enrico; De Luca, Gaetano; Saccorotti, Gilberto

    2016-04-01

    The GINGERino ring laser gyroscope (RLG) is a new large observatory-class RLG located in Gran Sasso underground laboratory (LNGS), one national laboratory of the INFN (Istituto Nazionale di Fisica Nucleare). The GINGERino apparatus funded by INFN in the context of a larger project of fundamental physics is intended as a pathfinder instrument to reach the high sensitivity needed to observe general relativity effects; more details are found at the URL (https://web2.infn.it/GINGER/index.php/it/). The sensitivity reached by our instrument in the first year after the set up permitted us to acquire important seismological data of ground rotations during the transit of seismic waves generated by seisms at different epicentral distances. RLGs are in fact the best sensors for capturing the rotational motions associated with the transit of seismic waves, thanks to the optical measurement principle, these instruments are in fact insensitive to translations. Ground translations are recorded by two seismometers: a Nanometrics Trillium 240 s and Guralp CMG 3T 360 s, the first instrument is part of the national earthquake monitoring program of the Istituto Nazionale di Geofisica e Vulcanologia (INGV) and provides the ground translation data to be compared to the RLG rotational data. We report the waveforms and the seismological analysis of some seismic events recorded during our first year of activity inside the LNGS laboratory.

  12. Limit of detection of a fiber optics gyroscope using a super luminescent radiation source

    International Nuclear Information System (INIS)

    Sandoval R, G.E.; Nikolaev, V.A.

    2003-01-01

    The main objective of this work is to establish the dependence of characteristics of the fiber optics gyroscope (FOG) with respect to the parameters of the super luminescent emission source based on doped optical fiber with rare earth elements (Super luminescent Fiber Source, SFS), argument the pumping rate election of the SFS to obtain characteristics limits of the FOG sensibility. By using this type of emission source in the FOG is recommend to use the rate when the direction of the pumping signal coincide with the super luminescent signal. The most results are the proposition and argumentation of the SFS election as emission source to be use in the FOG of the phase type. Such a decision allow to increase the characteristics of the FOG sensibility in comparison with the use of luminescent source of semiconductors emission which are extensively used in the present time. The use of emission source of the SFS type allow to come closer to the threshold of the obtained sensibility limit (detection limit) which is determined with the shot noise. (Author)

  13. Analysis and Optimization of Dynamic Measurement Precision of Fiber Optic Gyroscope

    Directory of Open Access Journals (Sweden)

    Hui Li

    2013-01-01

    Full Text Available In order to improve the dynamic performance of high precision interferometer fiber optic gyroscope (IFOG, the influencing factors of the fast response characteristics are analyzed based on a proposed assistant design setup, and a high dynamic detection method is proposed to suppress the adverse effects of the key influencing factors. The assistant design platform is built by using the virtual instrument technology for IFOG, which can monitor the closed-loop state variables in real time for analyzing the influence of both the optical components and detection circuit on the dynamic performance of IFOG. The analysis results indicate that nonlinearity of optical Sagnac effect, optical parameter uncertainty, dynamic characteristics of internal modules and time delay of signal detection circuit are the major causes of dynamic performance deterioration, which can induce potential system instability in practical control systems. By taking all these factors into consideration, we design a robust control algorithm to realize the high dynamic closed-loop detection of IFOG. Finally, experiments show that the improved 0.01 deg/h high precision IFOG with the proposed control algorithm can achieve fast tracking and good dynamic measurement precision.

  14. Real-time monitoring system for elderly people in detecting falling movement using accelerometer and gyroscope

    Science.gov (United States)

    Siregar, B.; Andayani, U.; Bahri, R. P.; Seniman; Fahmi, F.

    2018-03-01

    Most of the elderly people is experiencing a decrease in physical quality, especially the weakness in the legs. This will cause elderly easy to fall and can have a serious impact on their health if not getting help very quickly. It is, therefore, necessary to take immediate action against the falling cases experienced by the elderly. One such action is by developing supervision and detecting of falling movements in real-time, which is then the connection to a member of the family. In this research, we used Arduino Uno as a microcontroller, sensor accelerometer, and gyroscope that serves to measure falling movement of the elderly person and supported by GPS technology Ublox Neo 6M to provide information about coordinates. The result was the high accuracy of delivering notification data to server and accuracy of data delivery to family notification equal to 93,75%. The system successfully detects the direction of falling: forward, backward, left or right and able to distinguish between unintentional falling and conscious falling like a bow or prostrate position.

  15. High-Q microsphere resonators for angular velocity sensing in gyroscopes

    International Nuclear Information System (INIS)

    An, Panlong; Zheng, Yongqiu; Yan, Shubin; Xue, Chenyang; Liu, Jun; Wang, Wanjun

    2015-01-01

    A resonator gyroscope based on the Sagnac effect is proposed using a core unit that is generated by water-hydrogen flame melting. The relationship between the quality factor Q and diameter D is revealed. The Q factor of the spectral lines of the microsphere cavity coupling system, which uses tapered fibers, is found to be 10 6 or more before packaging with a low refractive curable ultraviolet polymer, although it drops to approximately 10 5 after packaging. In addition, a rotating test platform is built, and the transmission spectrum and discriminator curves of a microsphere cavity with Q of 3.22×10 6 are measured using a semiconductor laser (linewidth less than 1 kHz) and a real-time proportional-integral circuit tracking and feedback technique. Equations fitting the relation between the voltage and angular rotation rate are obtained. According to the experimentally measured parameters, the sensitivity of the microsphere-coupled system can reach 0.095 ∘ /s

  16. THERMAL PROTECTION AND THERMAL STABILIZATION OF FIBER-OPTICAL GYROSCOPE INCLUDED IN STRAPDOWN INERTIAL NAVIGATION SYSTEM

    Directory of Open Access Journals (Sweden)

    D. S. Gromov

    2014-03-01

    Full Text Available It is known, that temperature perturbations and thermal modes have significant influence on the accuracy of a fiber-optical gyroscope. Nowadays, thermal perturbations are among the main problems in the field of navigation accuracy. Review of existing methods for decrease of temperature influences on the accuracy of a strapdown inertial navigation system with fiberoptical gyros showed, that the usage of constructive and compensation methods only is insufficient and, therefore, thermostabilization is required. Reversible thermostabilization system is offered, its main executive elements are thermoelectric modules (Peltier’s modules, heat transfer from which is provided by heatsinks at work surfaces of modules. This variant of thermostabilization maintenance is considered; Peltier’s modules and temperature sensors for the system are chosen. Parameters of heatsinks for heat transfer intensification are calculated. Fans for necessary air circulation in the device are chosen and thickness of thermal isolation is calculated. Calculations of thermal modes of navigation system with thermostabilization are made in modern software Autodesk Simulation CFD. Comparison of results for present and previous researches and calculations shows essential decrease in gradients of temperature on gyro surfaces and better uniformity of temperature field in the whole device. Conclusions about efficiency of the given method usage in view of accuracy improvement of navigation system are made. Thermostabilization provision of a strapdown inertial navigation system with fiberoptical gyros is proved. Thermostabilization application in combination with compensational methods can reach a necessary accuracy of navigation system.

  17. A Novel Artificial Fish Swarm Algorithm for Recalibration of Fiber Optic Gyroscope Error Parameters

    Directory of Open Access Journals (Sweden)

    Yanbin Gao

    2015-05-01

    Full Text Available The artificial fish swarm algorithm (AFSA is one of the state-of-the-art swarm intelligent techniques, which is widely utilized for optimization purposes. Fiber optic gyroscope (FOG error parameters such as scale factors, biases and misalignment errors are relatively unstable, especially with the environmental disturbances and the aging of fiber coils. These uncalibrated error parameters are the main reasons that the precision of FOG-based strapdown inertial navigation system (SINS degraded. This research is mainly on the application of a novel artificial fish swarm algorithm (NAFSA on FOG error coefficients recalibration/identification. First, the NAFSA avoided the demerits (e.g., lack of using artificial fishes’ pervious experiences, lack of existing balance between exploration and exploitation, and high computational cost of the standard AFSA during the optimization process. To solve these weak points, functional behaviors and the overall procedures of AFSA have been improved with some parameters eliminated and several supplementary parameters added. Second, a hybrid FOG error coefficients recalibration algorithm has been proposed based on NAFSA and Monte Carlo simulation (MCS approaches. This combination leads to maximum utilization of the involved approaches for FOG error coefficients recalibration. After that, the NAFSA is verified with simulation and experiments and its priorities are compared with that of the conventional calibration method and optimal AFSA. Results demonstrate high efficiency of the NAFSA on FOG error coefficients recalibration.

  18. A novel artificial fish swarm algorithm for recalibration of fiber optic gyroscope error parameters.

    Science.gov (United States)

    Gao, Yanbin; Guan, Lianwu; Wang, Tingjun; Sun, Yunlong

    2015-05-05

    The artificial fish swarm algorithm (AFSA) is one of the state-of-the-art swarm intelligent techniques, which is widely utilized for optimization purposes. Fiber optic gyroscope (FOG) error parameters such as scale factors, biases and misalignment errors are relatively unstable, especially with the environmental disturbances and the aging of fiber coils. These uncalibrated error parameters are the main reasons that the precision of FOG-based strapdown inertial navigation system (SINS) degraded. This research is mainly on the application of a novel artificial fish swarm algorithm (NAFSA) on FOG error coefficients recalibration/identification. First, the NAFSA avoided the demerits (e.g., lack of using artificial fishes' pervious experiences, lack of existing balance between exploration and exploitation, and high computational cost) of the standard AFSA during the optimization process. To solve these weak points, functional behaviors and the overall procedures of AFSA have been improved with some parameters eliminated and several supplementary parameters added. Second, a hybrid FOG error coefficients recalibration algorithm has been proposed based on NAFSA and Monte Carlo simulation (MCS) approaches. This combination leads to maximum utilization of the involved approaches for FOG error coefficients recalibration. After that, the NAFSA is verified with simulation and experiments and its priorities are compared with that of the conventional calibration method and optimal AFSA. Results demonstrate high efficiency of the NAFSA on FOG error coefficients recalibration.

  19. AMA- and RWE- Based Adaptive Kalman Filter for Denoising Fiber Optic Gyroscope Drift Signal.

    Science.gov (United States)

    Yang, Gongliu; Liu, Yuanyuan; Li, Ming; Song, Shunguang

    2015-10-23

    An improved double-factor adaptive Kalman filter called AMA-RWE-DFAKF is proposed to denoise fiber optic gyroscope (FOG) drift signal in both static and dynamic conditions. The first factor is Kalman gain updated by random weighting estimation (RWE) of the covariance matrix of innovation sequence at any time to ensure the lowest noise level of output, but the inertia of KF response increases in dynamic condition. To decrease the inertia, the second factor is the covariance matrix of predicted state vector adjusted by RWE only when discontinuities are detected by adaptive moving average (AMA).The AMA-RWE-DFAKF is applied for denoising FOG static and dynamic signals, its performance is compared with conventional KF (CKF), RWE-based adaptive KF with gain correction (RWE-AKFG), AMA- and RWE- based dual mode adaptive KF (AMA-RWE-DMAKF). Results of Allan variance on static signal and root mean square error (RMSE) on dynamic signal show that this proposed algorithm outperforms all the considered methods in denoising FOG signal.

  20. Robust trajectory tracking control of a dual-arm space robot actuated by control moment gyroscopes

    Science.gov (United States)

    Jia, Yinghong; Misra, Arun K.

    2017-08-01

    It is a new design concept to employ control moment gyroscopes (CMGs) as reactionless actuators for space robots. Such actuation has several noticeable advantages such as weak dynamical coupling and low power consumption over traditional joint motor actuation. This paper presents a robust control law for a CMG-actuated space robot in presence of system uncertainties and closed-chain constraints. The control objective is to make the manipulation variables to track the desired trajectories, and reduce the possibility of CMG saturation simultaneously. A reduced-order dynamical equation in terms of independent motion variables is derived using Kane's equations. Desired trajectories of the independent motion variables are derived by minimum-norm trajectory planning algorithm, and an adaptive sliding mode controller with improved adaptation laws is proposed to drive the independent motion variables tracking the desired trajectories. Uniformly ultimate boundedness of the closed loop system is proven using Lyapunov method. The redundancy of the full-order actual control torques is utilized to generate a null torque vector which reduces the possibility of CMG angular momentum saturation while producing no effect on the reduced-order control input. Simulation results demonstrate the effectiveness of the proposed algorithms and the advantage of weak dynamical coupling of the CMG-actuated system.

  1. Vibration-Induced Errors in MEMS Tuning Fork Gyroscopes with Imbalance.

    Science.gov (United States)

    Fang, Xiang; Dong, Linxi; Zhao, Wen-Sheng; Yan, Haixia; Teh, Kwok Siong; Wang, Gaofeng

    2018-05-29

    This paper discusses the vibration-induced error in non-ideal MEMS tuning fork gyroscopes (TFGs). Ideal TFGs which are thought to be immune to vibrations do not exist, and imbalance between two gyros of TFGs is an inevitable phenomenon. Three types of fabrication imperfections (i.e., stiffness imbalance, mass imbalance, and damping imbalance) are studied, considering different imbalance radios. We focus on the coupling types of two gyros of TFGs in both drive and sense directions, and the vibration sensitivities of four TFG designs with imbalance are simulated and compared. It is found that non-ideal TFGs with two gyros coupled both in drive and sense directions (type CC TFGs) are the most insensitive to vibrations with frequencies close to the TFG operating frequencies. However, sense-axis vibrations with in-phase resonant frequencies of a coupled gyros system result in severe error outputs to TFGs with two gyros coupled in the sense direction, which is mainly attributed to the sense capacitance nonlinearity. With increasing stiffness coupled ratio of the coupled gyros system, the sensitivity to vibrations with operating frequencies is cut down, yet sensitivity to vibrations with in-phase frequencies is amplified.

  2. Two Novel Measurements for the Drive-Mode Resonant Frequency of a Micromachined Vibratory Gyroscope

    Directory of Open Access Journals (Sweden)

    Ancheng Wang

    2013-11-01

    Full Text Available To investigate the drive-mode resonance frequency of a micromachined vibratory gyroscope (MVG, one needs to measure it accurately and efficiently. The conventional approach to measure the resonant frequency is by performing a sweep frequency test and spectrum analysis. The method is time-consuming and inconvenient because of the requirements of many test points, a lot of data storage and off-line analyses. In this paper, we propose two novel measurement methods, the search method and track method, respectively. The former is based on the magnitude-frequency characteristics of the drive mode, utilizing a one-dimensional search technique. The latter is based on the phase-frequency characteristics, applying a feedback control loop. Their performances in precision, noise resistivity and efficiency are analyzed through detailed simulations. A test system is implemented based on a field programmable gate array (FPGA and experiments are carried out. By comparing with the common approach, feasibility and superiorities of the proposed methods are validated. In particular, significant efficiency improvements are achieved whereby the conventional frequency method consumes nearly 5,000 s to finish a measurement, while only 5 s is needed for the track method and 1 s for the search method.

  3. Key Processes of Silicon-On-Glass MEMS Fabrication Technology for Gyroscope Application.

    Science.gov (United States)

    Ma, Zhibo; Wang, Yinan; Shen, Qiang; Zhang, Han; Guo, Xuetao

    2018-04-17

    MEMS fabrication that is based on the silicon-on-glass (SOG) process requires many steps, including patterning, anodic bonding, deep reactive ion etching (DRIE), and chemical mechanical polishing (CMP). The effects of the process parameters of CMP and DRIE are investigated in this study. The process parameters of CMP, such as abrasive size, load pressure, and pH value of SF1 solution are examined to optimize the total thickness variation in the structure and the surface quality. The ratio of etching and passivation cycle time and the process pressure are also adjusted to achieve satisfactory performance during DRIE. The process is optimized to avoid neither the notching nor lag effects on the fabricated silicon structures. For demonstrating the capability of the modified CMP and DRIE processes, a z-axis micro gyroscope is fabricated that is based on the SOG process. Initial test results show that the average surface roughness of silicon is below 1.13 nm and the thickness of the silicon is measured to be 50 μm. All of the structures are well defined without the footing effect by the use of the modified DRIE process. The initial performance test results of the resonant frequency for the drive and sense modes are 4.048 and 4.076 kHz, respectively. The demands for this kind of SOG MEMS device can be fulfilled using the optimized process.

  4. Particle Filter with Novel Nonlinear Error Model for Miniature Gyroscope-Based Measurement While Drilling Navigation

    Directory of Open Access Journals (Sweden)

    Tao Li

    2016-03-01

    Full Text Available The derivation of a conventional error model for the miniature gyroscope-based measurement while drilling (MGWD system is based on the assumption that the errors of attitude are small enough so that the direction cosine matrix (DCM can be approximated or simplified by the errors of small-angle attitude. However, the simplification of the DCM would introduce errors to the navigation solutions of the MGWD system if the initial alignment cannot provide precise attitude, especially for the low-cost microelectromechanical system (MEMS sensors operated in harsh multilateral horizontal downhole drilling environments. This paper proposes a novel nonlinear error model (NNEM by the introduction of the error of DCM, and the NNEM can reduce the propagated errors under large-angle attitude error conditions. The zero velocity and zero position are the reference points and the innovations in the states estimation of particle filter (PF and Kalman filter (KF. The experimental results illustrate that the performance of PF is better than KF and the PF with NNEM can effectively restrain the errors of system states, especially for the azimuth, velocity, and height in the quasi-stationary condition.

  5. Particle Filter with Novel Nonlinear Error Model for Miniature Gyroscope-Based Measurement While Drilling Navigation.

    Science.gov (United States)

    Li, Tao; Yuan, Gannan; Li, Wang

    2016-03-15

    The derivation of a conventional error model for the miniature gyroscope-based measurement while drilling (MGWD) system is based on the assumption that the errors of attitude are small enough so that the direction cosine matrix (DCM) can be approximated or simplified by the errors of small-angle attitude. However, the simplification of the DCM would introduce errors to the navigation solutions of the MGWD system if the initial alignment cannot provide precise attitude, especially for the low-cost microelectromechanical system (MEMS) sensors operated in harsh multilateral horizontal downhole drilling environments. This paper proposes a novel nonlinear error model (NNEM) by the introduction of the error of DCM, and the NNEM can reduce the propagated errors under large-angle attitude error conditions. The zero velocity and zero position are the reference points and the innovations in the states estimation of particle filter (PF) and Kalman filter (KF). The experimental results illustrate that the performance of PF is better than KF and the PF with NNEM can effectively restrain the errors of system states, especially for the azimuth, velocity, and height in the quasi-stationary condition.

  6. Limit of detection of a fiber optics gyroscope using a super luminescent radiation source

    CERN Document Server

    Sandoval, G E

    2003-01-01

    The main objective of this work is to establish the dependence of characteristics of the fiber optics gyroscope (FOG) with respect to the parameters of the super luminescent emission source based on doped optical fiber with rare earth elements (Super luminescent Fiber Source, SFS), argument the pumping rate election of the SFS to obtain characteristics limits of the FOG sensibility. By using this type of emission source in the FOG is recommend to use the rate when the direction of the pumping signal coincide with the super luminescent signal. The most results are the proposition and argumentation of the SFS election as emission source to be use in the FOG of the phase type. Such a decision allow to increase the characteristics of the FOG sensibility in comparison with the use of luminescent source of semiconductors emission which are extensively used in the present time. The use of emission source of the SFS type allow to come closer to the threshold of the obtained sensibility limit (detection limit) which i...

  7. Optimization and Experimentation of Dual-Mass MEMS Gyroscope Quadrature Error Correction Methods.

    Science.gov (United States)

    Cao, Huiliang; Li, Hongsheng; Kou, Zhiwei; Shi, Yunbo; Tang, Jun; Ma, Zongmin; Shen, Chong; Liu, Jun

    2016-01-07

    This paper focuses on an optimal quadrature error correction method for the dual-mass MEMS gyroscope, in order to reduce the long term bias drift. It is known that the coupling stiffness and demodulation error are important elements causing bias drift. The coupling stiffness in dual-mass structures is analyzed. The experiment proves that the left and right masses' quadrature errors are different, and the quadrature correction system should be arranged independently. The process leading to quadrature error is proposed, and the Charge Injecting Correction (CIC), Quadrature Force Correction (QFC) and Coupling Stiffness Correction (CSC) methods are introduced. The correction objects of these three methods are the quadrature error signal, force and the coupling stiffness, respectively. The three methods are investigated through control theory analysis, model simulation and circuit experiments, and the results support the theoretical analysis. The bias stability results based on CIC, QFC and CSC are 48 °/h, 9.9 °/h and 3.7 °/h, respectively, and this value is 38 °/h before quadrature error correction. The CSC method is proved to be the better method for quadrature correction, and it improves the Angle Random Walking (ARW) value, increasing it from 0.66 °/√h to 0.21 °/√h. The CSC system general test results show that it works well across the full temperature range, and the bias stabilities of the six groups' output data are 3.8 °/h, 3.6 °/h, 3.4 °/h, 3.1 °/h, 3.0 °/h and 4.2 °/h, respectively, which proves the system has excellent repeatability.

  8. Multidimensional gray-wavelet processing in interferometric fiber-optic gyroscopes

    International Nuclear Information System (INIS)

    Yang, Yi; Wang, Zinan; Peng, Chao; Li, Zhengbin

    2013-01-01

    A multidimensional signal processing method for a single interferometric fiber-optic gyroscope (IFOG) is proposed, to the best of our knowledge, for the first time. The proposed method, based on a novel IFOG structure with quadrature demodulation, combines a multidimensional gray model (GM) and a wavelet compression technique for noise suppression and sensitivity enhancement. In the IFOG, two series of measured rotation rates are obtained simultaneously: an in-phase component and a quadrature component. Together with the traditionally measured rate, the three measured rates are processed by the combined gray-wavelet method. Simulations show that the intensity noise and non-reciprocal phase fluctuations are effectively suppressed by this method. Experimental comparisons with a one-dimensional GM(1, 1) model show that the proposed three-dimensional method achieves much better denoising performance. This advantage is validated by the Allan variance analysis: in a low-SNR (signal-to-noise ratio) experiment, our method reduces the angle random walk (ARW) and the bias instability (BI) from 1 × 10 −2  deg h −1/2 and 3 × 10 −2  deg h −1 to 1 × 10 −3  deg h −1/2 and 3 × 10 −3  deg h −1 , respectively; in a high-SNR experiment, our method reduces the ARW and the BI from 9 × 10 −4  deg h −1/2 and 5 × 10 −3  deg h −1 to 4 × 10 −4  deg h −1/2 and 3 × 10 −3  deg h −1 , respectively. Further, our method increases the dimension of the state-of-the-art IFOG technique from one to three, thus obtaining higher IFOG sensitivity and stability by exploiting the increase in available information. (paper)

  9. Multidimensional gray-wavelet processing in interferometric fiber-optic gyroscopes

    Science.gov (United States)

    Yang, Yi; Wang, Zinan; Peng, Chao; Li, Zhengbin

    2013-11-01

    A multidimensional signal processing method for a single interferometric fiber-optic gyroscope (IFOG) is proposed, to the best of our knowledge, for the first time. The proposed method, based on a novel IFOG structure with quadrature demodulation, combines a multidimensional gray model (GM) and a wavelet compression technique for noise suppression and sensitivity enhancement. In the IFOG, two series of measured rotation rates are obtained simultaneously: an in-phase component and a quadrature component. Together with the traditionally measured rate, the three measured rates are processed by the combined gray-wavelet method. Simulations show that the intensity noise and non-reciprocal phase fluctuations are effectively suppressed by this method. Experimental comparisons with a one-dimensional GM(1, 1) model show that the proposed three-dimensional method achieves much better denoising performance. This advantage is validated by the Allan variance analysis: in a low-SNR (signal-to-noise ratio) experiment, our method reduces the angle random walk (ARW) and the bias instability (BI) from 1 × 10-2 deg h-1/2 and 3 × 10-2 deg h-1 to 1 × 10-3 deg h-1/2 and 3 × 10-3 deg h-1, respectively; in a high-SNR experiment, our method reduces the ARW and the BI from 9 × 10-4 deg h-1/2 and 5 × 10-3 deg h-1 to 4 × 10-4 deg h-1/2 and 3 × 10-3 deg h-1, respectively. Further, our method increases the dimension of the state-of-the-art IFOG technique from one to three, thus obtaining higher IFOG sensitivity and stability by exploiting the increase in available information.

  10. Fibre optical gyroscopes in borehole logging; Einsatz faseroptischer Kreisel Technologien in der Bohrlochgeophysik

    Energy Technology Data Exchange (ETDEWEB)

    Stoll, J.B. [BGR, Hannover (Germany); Leven, M.; Steveling, E. [Inst. fuer Geophysik, Goettingen (Germany)

    2003-07-01

    A fibre optical gyroscope was installed in a borehole magnetometer in the framework of a DFG-funded pilot project carried out in co-operation with the Institute of Geophysics of Goettingen University. The measuring system was used in an ocean log in the NW Pacific for measuring the remnant section of the magnetic field of the strongly magnetic ocean crust and its direction. the system is completely independent of the magnetic field, which is not required as an orientation aid. Further applications are envisaged in online measuring of borehole or cavern geometries and subsequent orientation of borehole wall images using imaging procedures like FMS, FMI, or borehole televiewer. [German] Um die Drehwinkel eines im Raum rotierenden Messsystems zu erfassen, gibt es verschiedene Messtechniken, mit denen die Raumlage eines Messsystems gegenueber einem Inertialsystem bestimmt werden kann. Eine Gruppe von Drehratensensoren sind die sogenannten optischen Kreisel, die im folgenden naeher besprochen werden. Ein solcher faseroptischer Drehratensensor wurde im Rahmen eines von der DFG gefoerderten Pilotprojektes in Zusammenarbeit mit dem Geophysikalischen Institut der Universitaet Goettingen in ein Bohrlochmagnetometer eingebaut. Ziel des Pilotprojektes war es zu testen, mit welcher Genauigkeit die Horizontalkomponenten des Magnetometers mithilfe des faseroptischen Kreisels in Bezug auf ein erdfestes Koordinatensystem ausgerichtet werden koennen. Dieses Messsystem wurde in einer Ozeanbohrung im NW-Pazifik eingesetzt, mit dem Ziel den remanente Anteil des Magnetfeldes der stark magnetischen ozeanischen Kruste und dessen Richtung zu bestimmen. Mit diesem Sensor steht ein Messverfahren zur Verfuegung, das vom Magnetfeld als Orientierungshilfe vollstaendig unabhaengig ist. Weitere Anwendungsmoeglichkeiten dieser Messtechnik sind die online Vermessung der Geometrie von Bohrungen oder Kavernen und die nachtraegliche Orientierung von Abbildungen der Bohrlochwand mittels bildgebender

  11. Interface circuit for a multiple-beam tuning-fork gyroscope with high quality factors

    Science.gov (United States)

    Wang, Ren

    This research work presents the design, theoretical analysis, fabrication, interface electronics, and experimental results of a Silicon-On-Insulator (SOI) based Multiple-Beam Tuning-Fork Gyroscope (MB-TFG). Based on a numerical model of Thermo-Elastic Damping (TED), a Multiple-Beam Tuning-Fork Structure (MB-TFS) is designed with high Quality factors (Qs) in its two operation modes. A comprehensive theoretical analysis of the MB-TFG design is conducted to relate the design parameters to its operation parameters and further performance parameters. In conjunction with a mask that defines the device through trenches to alleviate severe fabrication effect on anchor loss, a simple one-mask fabrication process is employed to implement this MB-TFG design on SOI wafers. The fabricated MB-TFGs are tested with PCB-level interface electronics and a thorough comparison between the experimental results and a theoretical analysis is conducted to verify the MB-TFG design and accurately interpret the measured performance. The highest measured Qs of the fabricated MB-TFGs in vacuum are 255,000 in the drive-mode and 103,000 in the sense-mode, at a frequency of 15.7kHz. Under a frequency difference of 4Hz between the two modes (operation frequency is 16.8kHz) and a drive-mode vibration amplitude of 3.0um, the measured rate sensitivity is 80mVpp/°/s with an equivalent impedance of 6MQ. The calculated overall rate resolution of this device is 0.37/hrhiElz, while the measured Angle Random Walk (ARW) and bias instability are 6.67°/'vhr and 95°/hr, respectively.

  12. Optimization and Experimentation of Dual-Mass MEMS Gyroscope Quadrature Error Correction Methods

    Directory of Open Access Journals (Sweden)

    Huiliang Cao

    2016-01-01

    Full Text Available This paper focuses on an optimal quadrature error correction method for the dual-mass MEMS gyroscope, in order to reduce the long term bias drift. It is known that the coupling stiffness and demodulation error are important elements causing bias drift. The coupling stiffness in dual-mass structures is analyzed. The experiment proves that the left and right masses’ quadrature errors are different, and the quadrature correction system should be arranged independently. The process leading to quadrature error is proposed, and the Charge Injecting Correction (CIC, Quadrature Force Correction (QFC and Coupling Stiffness Correction (CSC methods are introduced. The correction objects of these three methods are the quadrature error signal, force and the coupling stiffness, respectively. The three methods are investigated through control theory analysis, model simulation and circuit experiments, and the results support the theoretical analysis. The bias stability results based on CIC, QFC and CSC are 48 °/h, 9.9 °/h and 3.7 °/h, respectively, and this value is 38 °/h before quadrature error correction. The CSC method is proved to be the better method for quadrature correction, and it improves the Angle Random Walking (ARW value, increasing it from 0.66 °/√h to 0.21 °/√h. The CSC system general test results show that it works well across the full temperature range, and the bias stabilities of the six groups’ output data are 3.8 °/h, 3.6 °/h, 3.4 °/h, 3.1 °/h, 3.0 °/h and 4.2 °/h, respectively, which proves the system has excellent repeatability.

  13. Development and evaluation of a gyroscope-based wheel rotation monitor for manual wheelchair users.

    Science.gov (United States)

    Hiremath, Shivayogi V; Ding, Dan; Cooper, Rory A

    2013-07-01

    To develop and evaluate a wireless gyroscope-based wheel rotation monitor (G-WRM) that can estimate speeds and distances traveled by wheelchair users during regular wheelchair propulsion as well as wheelchair sports such as handcycling, and provide users with real-time feedback through a smartphone application. The speeds and the distances estimated by the G-WRM were compared with the criterion measures by calculating absolute difference, mean difference, and percentage errors during a series of laboratory-based tests. Intraclass correlations (ICC) and the Bland-Altman plots were also used to assess the agreements between the G-WRM and the criterion measures. In addition, battery life and wireless data transmission tests under a number of usage conditions were performed. The percentage errors for the angular velocities, speeds, and distances obtained from three prototype G-WRMs were less than 3% for all the test trials. The high ICC values (ICC (3,1) > 0.94) and the Bland-Altman plots indicate excellent agreement between the estimated speeds and distances by the G-WRMs and the criterion measures. The battery life tests showed that the device could last for 35 hours in wireless mode and 139 hours in secure digital card mode. The wireless data transmission tests indicated less than 0.3% of data loss. The results indicate that the G-WRM is an appropriate tool for tracking a spectrum of wheelchair-related activities from regular wheelchair propulsion to wheelchair sports such as handcycling. The real-time feedback provided by the G-WRM can help wheelchair users self-monitor their everyday activities.

  14. Optimization and Experimentation of Dual-Mass MEMS Gyroscope Quadrature Error Correction Methods

    Science.gov (United States)

    Cao, Huiliang; Li, Hongsheng; Kou, Zhiwei; Shi, Yunbo; Tang, Jun; Ma, Zongmin; Shen, Chong; Liu, Jun

    2016-01-01

    This paper focuses on an optimal quadrature error correction method for the dual-mass MEMS gyroscope, in order to reduce the long term bias drift. It is known that the coupling stiffness and demodulation error are important elements causing bias drift. The coupling stiffness in dual-mass structures is analyzed. The experiment proves that the left and right masses’ quadrature errors are different, and the quadrature correction system should be arranged independently. The process leading to quadrature error is proposed, and the Charge Injecting Correction (CIC), Quadrature Force Correction (QFC) and Coupling Stiffness Correction (CSC) methods are introduced. The correction objects of these three methods are the quadrature error signal, force and the coupling stiffness, respectively. The three methods are investigated through control theory analysis, model simulation and circuit experiments, and the results support the theoretical analysis. The bias stability results based on CIC, QFC and CSC are 48 °/h, 9.9 °/h and 3.7 °/h, respectively, and this value is 38 °/h before quadrature error correction. The CSC method is proved to be the better method for quadrature correction, and it improves the Angle Random Walking (ARW) value, increasing it from 0.66 °/√h to 0.21 °/√h. The CSC system general test results show that it works well across the full temperature range, and the bias stabilities of the six groups’ output data are 3.8 °/h, 3.6 °/h, 3.4 °/h, 3.1 °/h, 3.0 °/h and 4.2 °/h, respectively, which proves the system has excellent repeatability. PMID:26751455

  15. Design and Simulation of a MEMS Control Moment Gyroscope for the Sub-Kilogram Spacecraft

    Directory of Open Access Journals (Sweden)

    Weizheng Yuan

    2010-04-01

    Full Text Available A novel design of a microelectromechanical systems (MEMS control moment gyroscope (MCMG was proposed in this paper in order to generate a torque output with a magnitude of 10-6 N∙m. The MCMG consists of two orthogonal angular vibration systems, i.e., the rotor and gimbal; the coupling between which is based on the Coriolis effect and will cause a torque output in the direction perpendicular to the two vibrations. The angular rotor vibration was excited by the in-plane electrostatic rotary comb actuators, while the angular gimbal vibration was driven by an out-of-plane electrostatic parallel plate actuator. A possible process flow to fabricate the structure was proposed and discussed step by step. Furthermore, an array configuration using four MCMGs as an effective element, in which the torque was generated with a phase difference of 90 degrees between every two MCMGs, was proposed to smooth the inherent fluctuation of the torque output for a vibrational MCMG. The parasitic torque was cancelled by two opposite MCMGs with a phase difference of 180 degrees. The designed MCMG was about 1.1 cm × 1.1 cm × 0.04 cm in size and 0.1 g in weight. The simulation results showed that the maximum torque output of a MCMG, the resonant frequency of which was approximately 1,000 Hz, was about 2.5 × 10-8 N∙m. The element with four MCMGs could generate a torque of 5 × 10-8 N∙m. The torque output could reach a magnitude of 10-6 N∙m when the frequency was improved from 1,000 Hz to 10,000 Hz. Using arrays of 4 × 4 effective elements on a 1 kg spacecraft with a standard form factor of 10 cm × 10 cm × 10 cm, a 10 degrees attitude change could be achieved in 26.96s.

  16. Love waves trains observed after the MW 8.1 Tehuantepec earthquake by an underground ring laser gyroscope

    Science.gov (United States)

    Simonelli, A.; Belfi, J.; Beverini, N.; Di Virgilio, A.; Giacomelli, U.; De Luca, G.; Igel, H.

    2017-12-01

    We report the observation and analysis of the MW 8.1 Tehuantepec earthquake-induced rotational ground motion as observed by the Gingerino ring laser gyroscope (RLG).This instrument is located inside the National laboratory of the "Istituto Nazionale di Fisica Nucleare" in Gran Sasso (Italy) in a deep underground environment.We compare the vertical rotation rate with the horizontal acceleration measured by a co-located broadband seismometer. This analysis, performed by means of a wavelet-based correlation method, permits to identify the G1,G2,G3,G4 onsets of the surface Love waves in the 120 to 280 seconds period range.

  17. Implementation of a smartphone as a wireless gyroscope platform for quantifying reduced arm swing in hemiplegie gait with machine learning classification by multilayer perceptron neural network.

    Science.gov (United States)

    LeMoyne, Robert; Mastroianni, Timothy

    2016-08-01

    Natural gait consists of synchronous and rhythmic patterns for both the lower and upper limb. People with hemiplegia can experience reduced arm swing, which can negatively impact the quality of gait. Wearable and wireless sensors, such as through a smartphone, have demonstrated the ability to quantify various features of gait. With a software application the smartphone (iPhone) can function as a wireless gyroscope platform capable of conveying a gyroscope signal recording as an email attachment by wireless connectivity to the Internet. The gyroscope signal recordings of the affected hemiplegic arm with reduced arm swing arm and the unaffected arm are post-processed into a feature set for machine learning. Using a multilayer perceptron neural network a considerable degree of classification accuracy is attained to distinguish between the affected hemiplegic arm with reduced arm swing arm and the unaffected arm.

  18. A Novel Offset Cancellation Based on Parasitic-Insensitive Switched-Capacitor Sensing Circuit for the Out-of-Plane Single-Gimbaled Decoupled CMOS-MEMS Gyroscope

    Science.gov (United States)

    Chang, Ming-Hui; Huang, Han-Pang

    2013-01-01

    This paper presents a novel parasitic-insensitive switched-capacitor (PISC) sensing circuit design in order to obtain high sensitivity and ultra linearity and reduce the parasitic effect for the out-of-plane single-gimbaled decoupled CMOS-MEMS gyroscope (SGDG). According to the simulation results, the proposed PISC circuit has better sensitivity and high linearity in a wide dynamic range. Experimental results also show a better performance. In addition, the PISC circuit can use signal processing to cancel the offset and noise. Thus, this circuit is very suitable for gyroscope measurement. PMID:23493122

  19. Effect of Space Vehicle Structure Vibration on Control Moment Gyroscope Dynamics

    Science.gov (United States)

    Dobrinskaya, Tatiana

    2008-01-01

    Control Moment Gyroscopes (CMGs) are used for non-propulsive attitude control of satellites and space stations, including the International Space Station (ISS). CMGs could be essential for future long duration space missions due to the fact that they help to save propellant. CMGs were successfully tested on the ground for many years, and have been successfully used on satellites. However, operations have shown that the CMG service life on the ISS is significantly shorter than predicted. Since the dynamic environment of the ISS differs greatly from the nominal environment of satellites, it was important to analyze how operations specific to the station (dockings and undockings, huge solar array motion, crew exercising, robotic operations, etc) can affect the CMG performance. This task became even more important since the first CMG failure onboard the ISS. The CMG failure resulted in the limitation of the attitude control capabilities, more propellant consumption, and additional operational issues. Therefore, the goal of this work was to find out how the vibrations of a space vehicle structure, caused by a variety of onboard operations, can affect the CMG dynamics and performance. The equations of CMG motion were derived and analyzed for the case when the gyro foundation can vibrate in any direction. The analysis was performed for unbalanced CMG gimbals to match the CMG configuration on ISS. The analysis showed that vehicle structure vibrations can amplify and significantly change the CMG motion if the gyro gimbals are unbalanced in flight. The resonance frequencies were found. It was shown that the resonance effect depends on the magnitude of gimbal imbalance, on the direction of a structure vibration, and on gimbal bearing friction. Computer modeling results of CMG dynamics affected by the external vibration are presented. The results can explain some of the CMG vibration telemetry observed on ISS. This work shows that balancing the CMG gimbals decreases the effect

  20. Influences of optical-spectrum errors on excess relative intensity noise in a fiber-optic gyroscope

    Science.gov (United States)

    Zheng, Yue; Zhang, Chunxi; Li, Lijing

    2018-03-01

    The excess relative intensity noise (RIN) generated from broadband sources degrades the angular-random-walk performance of a fiber-optic gyroscope dramatically. Many methods have been proposed and managed to suppress the excess RIN. However, the properties of the excess RIN under the influences of different optical errors in the fiber-optic gyroscope have not been systematically investigated. Therefore, it is difficult for the existing RIN-suppression methods to achieve the optimal results in practice. In this work, the influences of different optical-spectrum errors on the power spectral density of the excess RIN are theoretically analyzed. In particular, the properties of the excess RIN affected by the raised-cosine-type ripples in the optical spectrum are elaborately investigated. Experimental measurements of the excess RIN corresponding to different optical-spectrum errors are in good agreement with our theoretical analysis, demonstrating its validity. This work provides a comprehensive understanding of the properties of the excess RIN under the influences of different optical-spectrum errors. Potentially, it can be utilized to optimize the configurations of the existing RIN-suppression methods by accurately evaluating the power spectral density of the excess RIN.

  1. Magnetic, Acceleration Fields and Gyroscope Quaternion (MAGYQ-Based Attitude Estimation with Smartphone Sensors for Indoor Pedestrian Navigation

    Directory of Open Access Journals (Sweden)

    Valérie Renaudin

    2014-12-01

    Full Text Available The dependence of proposed pedestrian navigation solutions on a dedicated infrastructure is a limiting factor to the deployment of location based services. Consequently self-contained Pedestrian Dead-Reckoning (PDR approaches are gaining interest for autonomous navigation. Even if the quality of low cost inertial sensors and magnetometers has strongly improved, processing noisy sensor signals combined with high hand dynamics remains a challenge. Estimating accurate attitude angles for achieving long term positioning accuracy is targeted in this work. A new Magnetic, Acceleration fields and GYroscope Quaternion (MAGYQ-based attitude angles estimation filter is proposed and demonstrated with handheld sensors. It benefits from a gyroscope signal modelling in the quaternion set and two new opportunistic updates: magnetic angular rate update (MARU and acceleration gradient update (AGU. MAGYQ filter performances are assessed indoors, outdoors, with dynamic and static motion conditions. The heading error, using only the inertial solution, is found to be less than 10° after 1.5 km walking. The performance is also evaluated in the positioning domain with trajectories computed following a PDR strategy.

  2. Study on phase noise induced by 1/f noise of the modulator drive circuit in high-sensitivity fiber optic gyroscope

    Science.gov (United States)

    Teng, Fei; Jin, Jing; Li, Yong; Zhang, Chunxi

    2018-05-01

    The contribution of modulator drive circuit noise as a 1/f noise source to the output noise of the high-sensitivity interferometric fiber optic gyroscope (IFOG) was studied here. A noise model of closed-loop IFOG was built. By applying the simulated 1/f noise sequence into the model, a gyroscope output data series was acquired, and the corresponding power spectrum density (PSD) and the Allan variance curve were calculated to analyze the noise characteristic. The PSD curve was in the spectral shape of 1/f, which verifies that the modulator drive circuit induced a low frequency 1/f phase noise into the gyroscope. The random walk coefficient (RWC), a standard metric to characterize the noise performance of the IFOG, was calculated according to the Allan variance curve. Using an operational amplifier with an input 1/f noise of 520 nV/√Hz at 1 Hz, the RWC induced by this 1/f noise was 2 × 10-4°/√h, which accounts for 63% of the total RWC. To verify the correctness of the noise model we proposed, a high-sensitivity gyroscope prototype was built and tested. The simulated Allan variance curve gave a good rendition of the prototype actual measured curve. The error percentage between the simulated RWC and the measured value was less than 13%. According to the model, a noise reduction method is proposed and the effectiveness is verified by the experiment.

  3. Development of a New Surface Acoustic Wave Based Gyroscope on a X-112°Y LiTaO3 Substrate

    Directory of Open Access Journals (Sweden)

    Shitang He

    2011-11-01

    Full Text Available A new micro gyroscope based on the surface acoustic wave (SAW gyroscopic effect was developed. The SAW gyroscopic effect is investigated by applying the surface effective permittivity method in the regime of small ratios of the rotation velocity and the frequency of the SAW. The theoretical analysis indicates that the larger velocity shift was observed from the rotated X-112°Y LiTaO3 substrate. Then, two SAW delay lines with reverse direction and an operation frequency of 160 MHz are fabricated on a same X-112°Y LiTaO3 chip as the feedback of two SAW oscillators, which act as the sensor element. The single-phase unidirectional transducer (SPUDT and combed transducers were used to structure the delay lines to improve the frequency stability of the oscillator. The rotation of a piezoelectric medium gives rise to a shift of the propagation velocity of SAW due to the Coriolis force, resulting in the frequency shift of the SAW device, and hence, the evaluation of the sensor performance. Meanwhile, the differential structure was performed to double the sensitivity and compensate for the temperature effects. Using a precise rate table, the performance of the fabricated SAW gyroscope was evaluated experimentally. A sensitivity of 1.332 Hz deg−1 s at angular rates of up to 1,000 deg s−1 and good linearity are observed.

  4. Nonequilibrium statistical physics in a dithered ring laser gyroscope or quantum noise in pure and applied physics

    International Nuclear Information System (INIS)

    Schleich, W.; Dobiasch, P.

    1986-01-01

    A brief review is given of quantum noise in ring laser gyroscopes. Some the basic elements of ring laser theory, such as the Sagnac effect, the locking effect, and the influence of quantumnoise on the mean beat frequency versus rotation rate are discussed. The Langevin equation for the ase difference between the counterpropagating waves in the presence of any periodic and time symmetric dither is cast into a form which alows a qualitative discussion of the resulting lock-in curve as well as an exact expression in terms of infinite matrix continued fractions. The details of the transformation of the stochastic variable and the derivation of the exact expression for f>t may be found in appendices. Exact results are presented for two special cases of the dithering function: the harmonic and the square-wave bias

  5. Damped gyroscopic effects and axial-flexural-torsional coupling using spinning finite elements for wind-turbine blades characterization

    Science.gov (United States)

    Velazquez, Antonio; Swartz, R. Andrew

    2013-04-01

    Renewable energy sources like wind are important technologies, useful to alleviate for the current fossil-fuel crisis. Capturing wind energy in a more efficient way has resulted in the emergence of more sophisticated designs of wind turbines, particularly Horizontal-Axis Wind Turbines (HAWTs). To promote efficiency, traditional finite element methods have been widely used to characterize the aerodynamics of these types of multi-body systems and improve their design. Given their aeroelastic behavior, tapered-swept blades offer the potential to optimize energy capture and decrease fatigue loads. Nevertheless, modeling special complex geometries requires huge computational efforts necessitating tradeoffs between faster computation times at lower cost, and reliability and numerical accuracy. Indeed, the computational cost and the numerical effort invested, using traditional FE methods, to reproduce dependable aerodynamics of these complex-shape beams are sometimes prohibitive. A condensed Spinning Finite Element (SFE) method scheme is presented in this study aimed to alleviate this issue by means of modeling wind-turbine rotor blades properly with tapered-swept cross-section variations of arbitrary order via Lagrangian equations. Axial-flexural-torsional coupling is carried out on axial deformation, torsion, in-plane bending and out-of-plane bending using super-convergent elements. In this study, special attention is paid for the case of damped yaw effects, expressed within the described skew-symmetric damped gyroscopic matrix. Dynamics of the model are analyzed by achieving modal analysis with complex-number eigen-frequencies. By means of mass, damped gyroscopic, and stiffness (axial-flexural-torsional coupling) matrix condensation (order reduction), numerical analysis is carried out for several prototypes with different tapered, swept, and curved variation intensities, and for a practical range of spinning velocities at different rotation angles. A convergence study

  6. Gyroscopic behavior exhibited by the optical Kerr effect in bimetallic Au–Pt nanoparticles suspended in ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Fernández-Valdés, D.; Torres-Torres, C., E-mail: ctorrest@ipn.mx, E-mail: crstorres@yahoo.com.mx; Martínez-González, C. L. [Instituto Politécnico Nacional, Sección de Estudios de Posgrado e Investigación, Escuela Superior de Ingeniería Mecánica y Eléctrica Unidad Zacatenco (Mexico); Trejo-Valdez, M. [Instituto Politécnico Nacional, Escuela Superior de Ingeniería Química e Industrias Extractivas (Mexico); Hernández-Gómez, L. H. [Instituto Politécnico Nacional, Sección de Estudios de Posgrado e Investigación, Escuela Superior de Ingeniería Mecánica y Eléctrica Unidad Zacatenco (Mexico); Torres-Martínez, R. [Instituto Politécnico Nacional, Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada Unidad Querétaro (Mexico)

    2016-07-15

    The modification in the third-order nonlinear optical response exhibited by rotating bimetallic Au–Pt nanoparticles in an ethanol solution was analyzed. The samples were prepared by a sol–gel processing route. The anisotropy associated to the elemental composition of the nanoparticles was confirmed by high-resolution transmission electron microscopy and energy-dispersive X-ray spectroscopy measurements. The size of the nanoparticles varies in the range from 9 to 13 nm, with an average size of 11 nm. Changes in the spatial orientation of the nanomaterials automatically generated a variation in their plasmonic response evaluated by UV–Vis spectroscopy. A two-wave mixing experiment was conducted to explore an induced birefringence at 532 nm wavelength with nanosecond pulses interacting with the samples. A strong optical Kerr effect was identified to be the main responsible effect for the third-order nonlinear optical phenomenon exhibited by the nanoparticles. It was estimated that the rotation of inhomogeneous nanostructures can provide a remarkable change in the participation of different surface plasmon resonances, if they correspond to multimetallic nanoparticles. Potential applications for developing low-dimensional gyroscopic systems can be contemplated.

  7. Gyroscopic behavior exhibited by the optical Kerr effect in bimetallic Au–Pt nanoparticles suspended in ethanol

    International Nuclear Information System (INIS)

    Fernández-Valdés, D.; Torres-Torres, C.; Martínez-González, C. L.; Trejo-Valdez, M.; Hernández-Gómez, L. H.; Torres-Martínez, R.

    2016-01-01

    The modification in the third-order nonlinear optical response exhibited by rotating bimetallic Au–Pt nanoparticles in an ethanol solution was analyzed. The samples were prepared by a sol–gel processing route. The anisotropy associated to the elemental composition of the nanoparticles was confirmed by high-resolution transmission electron microscopy and energy-dispersive X-ray spectroscopy measurements. The size of the nanoparticles varies in the range from 9 to 13 nm, with an average size of 11 nm. Changes in the spatial orientation of the nanomaterials automatically generated a variation in their plasmonic response evaluated by UV–Vis spectroscopy. A two-wave mixing experiment was conducted to explore an induced birefringence at 532 nm wavelength with nanosecond pulses interacting with the samples. A strong optical Kerr effect was identified to be the main responsible effect for the third-order nonlinear optical phenomenon exhibited by the nanoparticles. It was estimated that the rotation of inhomogeneous nanostructures can provide a remarkable change in the participation of different surface plasmon resonances, if they correspond to multimetallic nanoparticles. Potential applications for developing low-dimensional gyroscopic systems can be contemplated.

  8. Design and Vibration Sensitivity Analysis of a MEMS Tuning Fork Gyroscope with an Anchored Diamond Coupling Mechanism

    Directory of Open Access Journals (Sweden)

    Yanwei Guan

    2016-04-01

    Full Text Available In this paper, a new micromachined tuning fork gyroscope (TFG with an anchored diamond coupling mechanism is proposed while the mode ordering and the vibration sensitivity are also investigated. The sense-mode of the proposed TFG was optimized through use of an anchored diamond coupling spring, which enables the in-phase mode frequency to be 108.3% higher than the anti-phase one. The frequencies of the in- and anti-phase modes in the sense direction are 9799.6 Hz and 4705.3 Hz, respectively. The analytical solutions illustrate that the stiffness difference ratio of the in- and anti-phase modes is inversely proportional to the output induced by the vibration from the sense direction. Additionally, FEM simulations demonstrate that the stiffness difference ratio of the anchored diamond coupling TFG is 16.08 times larger than the direct coupling one while the vibration output is reduced by 94.1%. Consequently, the proposed new anchored diamond coupling TFG can structurally increase the stiffness difference ratio to improve the mode ordering and considerably reduce the vibration sensitivity without sacrificing the scale factor.

  9. A novel tri-axis MEMS gyroscope with in-plane tetra-pendulum proof masses and enhanced sensitive springs

    International Nuclear Information System (INIS)

    Wang, M C; Jiao, J W; Yan, P L; Mi, B W; Qin, S

    2014-01-01

    This paper presents a tri-axis MEMS gyroscope design with novel tetra-pendulum proof masses for X-, Y-axis and regular proof masses for Z-axis rate sensing, which are all coupled with and embedded in a conventional tuning fork driving frame. The four pendulum proof masses are suspended via the torsional springs to a common center anchor and can be driven to swing around the anchor via the tilted transforming springs as the driving frame is oscillated in an anti-phase mode. As an X-, Y-axis angular rate is applied, the tetra-pendulum proof masses will rotate around the torsional springs in pairs for X- and Y-axis differential sensing, respectively. In particular, we investigated the relationship between the tilting angle of the transforming spring and its transforming efficiency, i.e. the amplitude ratio of the pendulum's swing to the driving oscillation, which shows a straight impact on the sensitivity. By theoretical analysis and Ansys simulation, we achieved an optimal tilting angle of 22.5°, which extends along the angular bisector of the pendulum's and driving mass’ moving direction and demonstrates a significant increase in transforming efficiency by about 40%, compared with the trivial tilting angle of 45°. By employing an SOI-based bulk micromachining process, the prototype device with the optimal design of the transforming spring (type I) and that with the trivial design (type II) for reference have been successfully fabricated. As expected, the testing results indicate an increase of more than 20% in the X- and Y- sensitivities, which is mainly from the enhanced sensitive transforming springs. (paper)

  10. Rotational motions from the 2016, Central Italy seismic sequence, as observed by an underground ring laser gyroscope

    Science.gov (United States)

    Simonelli, A.; Igel, H.; Wassermann, J.; Belfi, J.; Di Virgilio, A.; Beverini, N.; De Luca, G.; Saccorotti, G.

    2018-05-01

    We present the analysis of rotational and translational ground motions from earthquakes recorded during October/November, 2016, in association with the Central Italy seismic-sequence. We use co-located measurements of the vertical ground rotation rate from a large ring laser gyroscope (RLG), and the three components of ground velocity from a broadband seismometer. Both instruments are positioned in a deep underground environment, within the Gran Sasso National Laboratories (LNGS) of the Istituto Nazionale di Fisica Nucleare (INFN). We collected dozens of events spanning the 3.5-5.9 Magnitude range, and epicentral distances between 30 km and 70 km. This data set constitutes an unprecedented observation of the vertical rotational motions associated with an intense seismic sequence at local distance. Under the plane wave approximation we process the data set in order to get an experimental estimation of the events back azimuth. Peak values of rotation rate (PRR) and horizontal acceleration (PGA) are markedly correlated, according to a scaling constant which is consistent with previous measurements from different earthquake sequences. We used a prediction model in use for Italy to calculate the expected PGA at the recording site, obtaining consequently predictions for PRR. Within the modeling uncertainties, predicted rotations are consistent with the observed ones, suggesting the possibility of establishing specific attenuation models for ground rotations, like the scaling of peak velocity and peak acceleration in empirical ground-motion prediction relationships. In a second step, after identifying the direction of the incoming wave-field, we extract phase velocity data using the spectral ratio of the translational and rotational components.. This analysis is performed over time windows associated with the P-coda, S-coda and Lg phase. Results are consistent with independent estimates of shear-wave velocities in the shallow crust of the Central Apennines.

  11. Averaged Propulsive Body Acceleration (APBA Can Be Calculated from Biologging Tags That Incorporate Gyroscopes and Accelerometers to Estimate Swimming Speed, Hydrodynamic Drag and Energy Expenditure for Steller Sea Lions.

    Directory of Open Access Journals (Sweden)

    Colin Ware

    Full Text Available Forces due to propulsion should approximate forces due to hydrodynamic drag for animals horizontally swimming at a constant speed with negligible buoyancy forces. Propulsive forces should also correlate with energy expenditures associated with locomotion-an important cost of foraging. As such, biologging tags containing accelerometers are being used to generate proxies for animal energy expenditures despite being unable to distinguish rotational movements from linear movements. However, recent miniaturizations of gyroscopes offer the possibility of resolving this shortcoming and obtaining better estimates of body accelerations of swimming animals. We derived accelerations using gyroscope data for swimming Steller sea lions (Eumetopias jubatus, and determined how well the measured accelerations correlated with actual swimming speeds and with theoretical drag. We also compared dive averaged dynamic body acceleration estimates that incorporate gyroscope data, with the widely used Overall Dynamic Body Acceleration (ODBA metric, which does not use gyroscope data. Four Steller sea lions equipped with biologging tags were trained to swim alongside a boat cruising at steady speeds in the range of 4 to 10 kph. At each speed, and for each dive, we computed a measure called Gyro-Informed Dynamic Acceleration (GIDA using a method incorporating gyroscope data with accelerometer data. We derived a new metric-Averaged Propulsive Body Acceleration (APBA, which is the average gain in speed per flipper stroke divided by mean stroke cycle duration. Our results show that the gyro-based measure (APBA is a better predictor of speed than ODBA. We also found that APBA can estimate average thrust production during a single stroke-glide cycle, and can be used to estimate energy expended during swimming. The gyroscope-derived methods we describe should be generally applicable in swimming animals where propulsive accelerations can be clearly identified in the signal

  12. Detection of patient movement during CBCT examination using video observation compared with an accelerometer-gyroscope tracking system.

    Science.gov (United States)

    Spin-Neto, Rubens; Matzen, Louise H; Schropp, Lars; Gotfredsen, Erik; Wenzel, Ann

    2017-02-01

    To compare video observation (VO) with a novel three-dimensional registration method, based on an accelerometer-gyroscope (AG) system, to detect patient movement during CBCT examination. The movements were further analyzed according to complexity and patient age. In 181 patients (118 females/63 males; age average 30 years, range: 9-84 years), 206 CBCT examinations were performed, which were video-recorded during examination. An AG was, at the same time, attached to the patient head to track head position in three dimensions. Three observers scored patient movement (yes/no) by VO. AG provided movement data on the x-, y- and z-axes. Thresholds for AG-based registration were defined at 0.5, 1, 2, 3 and 4 mm (movement distance). Movement detected by VO was compared with that registered by AG, according to movement complexity (uniplanar vs multiplanar, as defined by AG) and patient age (≤15, 16-30 and ≥31 years). According to AG, movement ≥0.5 mm was present in 160 (77.7%) examinations. According to VO, movement was present in 46 (22.3%) examinations. One VO-detected movement was not registered by AG. Overall, VO did not detect 71.9% of the movements registered by AG at the 0.5-mm threshold. At a movement distance ≥4 mm, 20% of the AG-registered movements were not detected by VO. Multiplanar movements such as lateral head rotation (72.1%) and nodding/swallowing (52.6%) were more often detected by VO in comparison with uniplanar movements, such as head lifting (33.6%) and anteroposterior translation (35.6%), at the 0.5-mm threshold. The prevalence of patients who move was highest in patients younger than 16 years (64.3% for VO and 92.3% for AG-based registration at the 0.5-mm threshold). AG-based movement registration resulted in a higher prevalence of patient movement during CBCT examination than VO-based registration. Also, AG-registered multiplanar movements were more frequently detected by VO than uniplanar movements. The prevalence of patients who move

  13. Rotational motions from the 2016, Central Italy seismic sequence, as observed by an underground ring laser gyroscope

    Science.gov (United States)

    Simonelli, Andreino; Belfi, Jacopo; Beverini, Nicolò; Di Virgilio, Angela; Maccioni, Enrico; De Luca, Gaetano; Saccorotti, Gilberto; Wassermann, Joachim; Igel, Heiner

    2017-04-01

    We present analyses of rotational and translational ground motions from earthquakes recorded during October-November, 2016, in association with the Central Italy seismic-sequence. We use co-located measurements of the vertical ground rotation rate from a large ring laser gyroscope (RLG), and the three components of ground velocity from a broadband seismometer. Both instruments are positioned in a deep underground environment, within the Gran Sasso National Laboratories (LNGS) of the Istituto Nazionale di Fisica Nucleare (INFN). We collected dozen of events spanning the 3.5-5.9 Magnitude range, and epicentral distances between 40 km and 80 km. This data set constitutes an unprecedented observation of the vertical rotational motions associated with an intense seismic sequence at local distance. In theory - assuming plane wave propagation - the ratio between the vertical rotation rate and the transverse acceleration permits, in a single station approach, the estimation of apparent phase velocity in the case of SH arrivals or real phase velocity in the case of Love surface waves. This is a standard approach for the analysis of earthquakes at teleseismic distances, and the results reported by the literature are compatible with the expected phase velocities from the PREM model. Here we extend the application of the same approach to local events, thus exploring higher frequency ranges and larger rotation rate amplitudes. We use a novel approach to joint rotation/acceleration analysis based on the continuous wavelet transform (CWT). Wavelet coherence (WTC) is used as a filter for identifying those regions of the time-period plane where the rotation rate and transverse acceleration signals exhibit significant coherence. This allows retrieving estimates of phase velocities over the period range spanned by correlated arrivals. Coherency among ground rotation and translation is also observed throughout the coda of the P-wave arrival, an observation which is interpreted in

  14. Analysis of pelvic movement in the elderly during walking using a posture monitoring system equipped with a triaxial accelerometer and a gyroscope.

    Science.gov (United States)

    Ishigaki, Norio; Kimura, Teiji; Usui, Yuki; Aoki, Kaoru; Narita, Nobuyo; Shimizu, Masayuki; Hara, Kazuo; Ogihara, Nobuhide; Nakamura, Koichi; Kato, Hiroyuki; Ohira, Masayoshi; Yokokawa, Yoshiharu; Miyoshi, Kei; Murakami, Narumichi; Okada, Shinpei; Nakamura, Tomokazu; Saito, Naoto

    2011-06-03

    The incidence of falls in the elderly is increasing with the aging of society and is becoming a major public health issue. From the viewpoint of prevention of falls, it is important to evaluate the stability of the gait in the elderly people. The pelvic movement, which is a critical factor for walking stability, was analyzed using a posture monitoring system equipped with a triaxial accelerometer and a gyroscope. The subjects were 95 elderly people over 60 years of age. The criteria for instability were open-eye standing on one leg for 15s or less, and 11s or more on 3m timed up and go test. Forty subjects who did not meet both of these criteria comprised the stable group, and the remaining 55 subjects comprised the unstable group. Pelvic movement during walking was compared between the two groups. The angle, angular velocity, and acceleration were analyzed based on the wave shape derived from the device worn around the second sacral. The results indicated that pelvic movement was lower in all three directions in the unstable group compared to the stable group, and the changes in the pelvic movement during walking in unstable elderly people were also reduced. This report is the first to evaluate pelvic movement by both a triaxial accelerometer and a triaxial gyroscope simultaneously. The characteristics of pelvic movement during walking can be applied in screening to identify elderly people with instability, which is the main risk factor associated with falls. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. The Bomb-Gyroscopes

    Directory of Open Access Journals (Sweden)

    Yuri F. Katorin

    2016-09-01

    Full Text Available In the article it is described about the attack at night 16 of May 1943 of year by the English aircraft of 617-y of the squadron of German dams in the Ruhr pond with the use of bombs “Upkeep” and the history of their creation by designer Barns Neville Wallis, is described the device of this weapon and the tactics of its application. The motion of operation is analyzed, in detail it is told about the actions of the crews of the aircraft, тhe motion of operation is analyzed, the losses of sides and consequence of the destruction of dams for the German defense industry are given.

  16. Nuclear magnetic resonance gyroscope

    International Nuclear Information System (INIS)

    Grover, B.C.

    1984-01-01

    A nuclear magnetic resonance gyro using two nuclear magnetic resonance gases, preferably xenon 129 and xenon 131, together with two alkaline metal vapors, preferably rubidium, potassium or cesium, one of the two alkaline metal vapors being pumped by light which has the wavelength of that alkaline metal vapor, and the other alkaline vapor being illuminated by light which has the wavelength of that other alkaline vapor

  17. A Noise Reduction Method for Dual-Mass Micro-Electromechanical Gyroscopes Based on Sample Entropy Empirical Mode Decomposition and Time-Frequency Peak Filtering.

    Science.gov (United States)

    Shen, Chong; Li, Jie; Zhang, Xiaoming; Shi, Yunbo; Tang, Jun; Cao, Huiliang; Liu, Jun

    2016-05-31

    The different noise components in a dual-mass micro-electromechanical system (MEMS) gyroscope structure is analyzed in this paper, including mechanical-thermal noise (MTN), electronic-thermal noise (ETN), flicker noise (FN) and Coriolis signal in-phase noise (IPN). The structure equivalent electronic model is established, and an improved white Gaussian noise reduction method for dual-mass MEMS gyroscopes is proposed which is based on sample entropy empirical mode decomposition (SEEMD) and time-frequency peak filtering (TFPF). There is a contradiction in TFPS, i.e., selecting a short window length may lead to good preservation of signal amplitude but bad random noise reduction, whereas selecting a long window length may lead to serious attenuation of the signal amplitude but effective random noise reduction. In order to achieve a good tradeoff between valid signal amplitude preservation and random noise reduction, SEEMD is adopted to improve TFPF. Firstly, the original signal is decomposed into intrinsic mode functions (IMFs) by EMD, and the SE of each IMF is calculated in order to classify the numerous IMFs into three different components; then short window TFPF is employed for low frequency component of IMFs, and long window TFPF is employed for high frequency component of IMFs, and the noise component of IMFs is wiped off directly; at last the final signal is obtained after reconstruction. Rotation experimental and temperature experimental are carried out to verify the proposed SEEMD-TFPF algorithm, the verification and comparison results show that the de-noising performance of SEEMD-TFPF is better than that achievable with the traditional wavelet, Kalman filter and fixed window length TFPF methods.

  18. A Noise Reduction Method for Dual-Mass Micro-Electromechanical Gyroscopes Based on Sample Entropy Empirical Mode Decomposition and Time-Frequency Peak Filtering

    Directory of Open Access Journals (Sweden)

    Chong Shen

    2016-05-01

    Full Text Available The different noise components in a dual-mass micro-electromechanical system (MEMS gyroscope structure is analyzed in this paper, including mechanical-thermal noise (MTN, electronic-thermal noise (ETN, flicker noise (FN and Coriolis signal in-phase noise (IPN. The structure equivalent electronic model is established, and an improved white Gaussian noise reduction method for dual-mass MEMS gyroscopes is proposed which is based on sample entropy empirical mode decomposition (SEEMD and time-frequency peak filtering (TFPF. There is a contradiction in TFPS, i.e., selecting a short window length may lead to good preservation of signal amplitude but bad random noise reduction, whereas selecting a long window length may lead to serious attenuation of the signal amplitude but effective random noise reduction. In order to achieve a good tradeoff between valid signal amplitude preservation and random noise reduction, SEEMD is adopted to improve TFPF. Firstly, the original signal is decomposed into intrinsic mode functions (IMFs by EMD, and the SE of each IMF is calculated in order to classify the numerous IMFs into three different components; then short window TFPF is employed for low frequency component of IMFs, and long window TFPF is employed for high frequency component of IMFs, and the noise component of IMFs is wiped off directly; at last the final signal is obtained after reconstruction. Rotation experimental and temperature experimental are carried out to verify the proposed SEEMD-TFPF algorithm, the verification and comparison results show that the de-noising performance of SEEMD-TFPF is better than that achievable with the traditional wavelet, Kalman filter and fixed window length TFPF methods.

  19. Development of a Web-Based Indoor Navigation System Using an Accelerometer and Gyroscope: A Case Study at The Faculty of Natural Sciences of Comenius University

    Science.gov (United States)

    Štefanička, Tomáš; Ďuračiová, Renata; Seres, Csaba

    2017-12-01

    As a complex of buildings, the Faculty of Natural Sciences of the Comenius University in Bratislava tends to be difficult to navigate in spite of its size. An indoor navigation application could potentially save a lot of time and frustration. There are currently numerous technologies used in indoor navigation systems. Some of them focus on a high degree of precision and require significant financial investment; others provide only static information about a current location. In this paper we focused on the determination of an approximate location using inertial measurement systems available on most smartphones, i.e., a gyroscope and an accelerometer. The actual position of the device was calculated using "a walk detection method" based on a delayed lack of motion. We have developed an indoor navigation application that relies solely on open source JavaScript libraries to visualize the interior of the building and calculate the shortest path utilizing Dijsktra's routing algorithm. The application logic is located on the client side, so the software is able to work offline. Our solution represents an accessible lowcost and platform-independent web application that can significantly improve navigation at the Faculty of Natural Sciences. Although our application has been developed on a specific building complex, it could be used in other interiors as well.

  20. Mapping and correction of the CMM workspace error with the use of an electronic gyroscope and neural networks--practical application.

    Science.gov (United States)

    Swornowski, Pawel J

    2013-01-01

    The article presents the application of neural networks in determining and correction of the deformation of a coordinate measuring machine (CMM) workspace. The information about the CMM errors is acquired using an ADXRS401 electronic gyroscope. A test device (PS-20 module) was built and integrated with a commercial measurement system based on the SP25M passive scanning probe and with a PH10M module (Renishaw). The proposed solution was tested on a Kemco 600 CMM and on a DEA Global Clima CMM. In the former case, correction of the CMM errors was performed using the source code of WinIOS software owned by The Institute of Advanced Manufacturing Technology, Cracow, Poland and in the latter on an external PC. Optimum parameters of full and simplified mapping of a given layer of the CMM workspace were determined for practical applications. The proposed method can be employed for the interim check (ISO 10360-2 procedure) or to detect local CMM deformations, occurring when the CMM works at high scanning speeds (>20 mm/s). © Wiley Periodicals, Inc.

  1. Effect of nonlinear electrostatic forces on the dynamic behaviour of a capacitive ring-based Coriolis Vibrating Gyroscope under severe shock

    Science.gov (United States)

    Chouvion, B.; McWilliam, S.; Popov, A. A.

    2018-06-01

    This paper investigates the dynamic behaviour of capacitive ring-based Coriolis Vibrating Gyroscopes (CVGs) under severe shock conditions. A general analytical model is developed for a multi-supported ring resonator by describing the in-plane ring response as a finite sum of modes of a perfect ring and the electrostatic force as a Taylor series expansion. It is shown that the supports can induce mode coupling and that mode coupling occurs when the shock is severe and the electrostatic forces are nonlinear. The influence of electrostatic nonlinearity is investigated by numerically simulating the governing equations of motion. For the severe shock cases investigated, when the electrode gap reduces by ∼ 60 % , it is found that three ring modes of vibration (1 θ, 2 θ and 3 θ) and a 9th order force expansion are needed to obtain converged results for the global shock behaviour. Numerical results when the 2 θ mode is driven at resonance indicate that electrostatic nonlinearity introduces mode coupling which has potential to reduce sensor performance under operating conditions. Under some circumstances it is also found that severe shocks can cause the vibrating response to jump to another stable state with much lower vibration amplitude. This behaviour is mainly a function of shock amplitude and rigid-body motion damping.

  2. Design, dynamics and control of an Adaptive Singularity-Free Control Moment Gyroscope actuator for microspacecraft Attitude Determination and Control System

    Science.gov (United States)

    Viswanathan, Sasi Prabhakaran

    Design, dynamics, control and implementation of a novel spacecraft attitude control actuator called the "Adaptive Singularity-free Control Moment Gyroscope" (ASCMG) is presented in this dissertation. In order to construct a comprehensive attitude dynamics model of a spacecraft with internal actuators, the dynamics of a spacecraft with an ASCMG, is obtained in the framework of geometric mechanics using the principles of variational mechanics. The resulting dynamics is general and complete model, as it relaxes the simplifying assumptions made in prior literature on Control Moment Gyroscopes (CMGs) and it also addresses the adaptive parameters in the dynamics formulation. The simplifying assumptions include perfect axisymmetry of the rotor and gimbal structures, perfect alignment of the centers of mass of the gimbal and the rotor etc. These set of simplifying assumptions imposed on the design and dynamics of CMGs leads to adverse effects on their performance and results in high manufacturing cost. The dynamics so obtained shows the complex nonlinear coupling between the internal degrees of freedom associated with an ASCMG and the spacecraft bus's attitude motion. By default, the general ASCMG cluster can function as a Variable Speed Control Moment Gyroscope, and reduced to function in CMG mode by spinning the rotor at constant speed, and it is shown that even when operated in CMG mode, the cluster can be free from kinematic singularities. This dynamics model is then extended to include the effects of multiple ASCMGs placed in the spacecraft bus, and sufficient conditions for non-singular ASCMG cluster configurations are obtained to operate the cluster both in VSCMG and CMG modes. The general dynamics model of the ASCMG is then reduced to that of conventional VSCMGs and CMGs by imposing the standard set of simplifying assumptions used in prior literature. The adverse effects of the simplifying assumptions that lead to the complexities in conventional CMG design, and

  3. Frequency characteristic measurement of a fiber optic gyroscope using a correlation spectrum analysis method based on a pseudo-random sequence

    International Nuclear Information System (INIS)

    Li, Yang; Chen, Xingfan; Liu, Cheng

    2015-01-01

    The frequency characteristic is an important indicator of a system’s dynamic performance. The identification of a fiber optic gyroscope (FOG)’s frequency characteristic using a correlation spectrum analysis method based on a pseudo-random sequence is proposed. Taking the angle vibrator as the source of the test rotation stimulation and a pseudo-random sequence as the test signal, the frequency characteristic of a FOG is calculated according to the power spectral density of the rotation rate signal and the cross-power spectral density of the FOG’s output signal and rotation rate signal. A theoretical simulation is done to confirm the validity of this method. An experiment system is built and the test results indicate that the measurement error of the normalized amplitude–frequency response is less than 0.01, that the error of the phase–frequency response is less than 0.3 rad, and the overall measurement accuracy is superior to the traditional frequency-sweep method. By using this method, the FOG’s amplitude–frequency response and phase–frequency response can be measured simultaneously, quickly, accurately, and with a high frequency resolution. The described method meets the requirements of engineering applications. (paper)

  4. Assessment of magneto-optic Faraday effect-based drift on interferometric single-mode fiber optic gyroscope (IFOG) as a function of variable degree of polarization (DOP)

    International Nuclear Information System (INIS)

    Çelikel, Oğuz; Sametoğlu, Ferhat

    2012-01-01

    In this study, a novel interferometric fiber optic gyroscope (IFOG), which has a different depolarizer structure, is designed in TUBITAK UME (National Metrology Institute of Turkey) to experimentally and relatively evaluate the effect of the degree of polarization on the Faraday effect-based drift of the light waves injected into both arms of a Sagnac interferometer. In order to observe whether or not any change occurs in the Faraday-based drift, depending on the variations in degree of polarization (DOP), a triple structure-depolarizer IFOG possessing adjustable DOP is firstly designed and prototyped. The minimum DOP achieved with triple structure-depolarizers is typically 0.15% for both clockwise (CW) and counterclockwise (CCW) light waves at both arms of the Sagnac interferometer. The experimental evaluations about the drift are given for DOP changes extending from 78.00% to 0.15% together with two main and different theoretical approaches in the literature. According to the experimental evaluations given herein, it is experimentally proved that the Faraday-based drift does not change depending on DOP values of both CW and CCW light waves injected into the single-mode (SM) sensing coil and it is impossible to state a concept of a depolarized IFOG by considering the polarization state at the entrance arms of the SM sensing coil. (paper)

  5. Photonic-crystal fibers gyroscope

    Directory of Open Access Journals (Sweden)

    Ali Muse Haider

    2015-01-01

    Full Text Available In this paper we proposed to use of a photonic crystal fiber with an inner hollow defect. The use of such fibers is not affected by a material medium on the propagation of optical radiation. Photonic crystal fibers present special properties and capabilities that lead to an outstanding potential for sensing applications

  6. Limit of detection of a fiber optics gyroscope using a super luminescent radiation source; Limite de deteccion de un giroscopio de fibra optica usando una fuente de radiacion superluminiscente

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval R, G.E. [Laboratorio de Optica Aplicada, Centro de Ciencias Aplicadas y Desarrollo Tecnologico, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-186, 04510 Mexico D.F. (Mexico); Nikolaev, V.A. [Departamento de Optica y Radiofisica Cuantica, Universidad Estatal de Telecomunicaciones de San Petersburgo, M.A. Bonch-Bruyevich, Kanal Moika 61, Saint Petersburg 191186, (Russian Federation)

    2003-07-01

    The main objective of this work is to establish the dependence of characteristics of the fiber optics gyroscope (FOG) with respect to the parameters of the super luminescent emission source based on doped optical fiber with rare earth elements (Super luminescent Fiber Source, SFS), argument the pumping rate election of the SFS to obtain characteristics limits of the FOG sensibility. By using this type of emission source in the FOG is recommend to use the rate when the direction of the pumping signal coincide with the super luminescent signal. The most results are the proposition and argumentation of the SFS election as emission source to be use in the FOG of the phase type. Such a decision allow to increase the characteristics of the FOG sensibility in comparison with the use of luminescent source of semiconductors emission which are extensively used in the present time. The use of emission source of the SFS type allow to come closer to the threshold of the obtained sensibility limit (detection limit) which is determined with the shot noise. (Author)

  7. Estimating orientation with gyroscopes and accelerometers

    NARCIS (Netherlands)

    Luinge, Hendrik J.; Veltink, Petrus H.; Baten, Christian T.M.

    1999-01-01

    Many systems for recording human movement need some reference from beacons near the subject, such as video cameras. Our goal is to measure human kinematics with sensors that are placed on the segments of interest. This way, experiments in which human movement is recorded are not restricted to a lab.

  8. Circuit, especially for digital nuclear gyroscope systems

    International Nuclear Information System (INIS)

    Lowdenslager, J.R.

    1974-01-01

    The circuit with at least one or two spin generator shows a digital phase synchronizing loop in solid-state construction without movable mechanical parts. It is stable, may be turned in one direction any number of times without saturation, and also remains phase-synchronized when input signals are turned off. For this purpose, crystal oscillators with certain resonance frequencies are used. The spin generators are coupled at the outled side with filtering, squaring, and differential connections generating control impulses synchronous to the spin generators. Step divider circuits are connected to the oscillators, which act upon flip-flop registers. This is controlled by the filtering, squaring, and differential connections. Furthermore, field proportional control circuits with registers, advancing and delay circuits are provided, the registers being connected at the outlet side with digital adders and subtractors. The digital adder serves inertial-related purposes. (DG) [de

  9. The Anatomy of the Gyroscope. Part 1

    Science.gov (United States)

    1988-02-01

    Vysteine Acta Physica Polonica 6 (1937) pp. 163-200 Ma-"rosov, V.M. On the stability of groscopic stabilicea Applied Mathematics & Mechanics 24 (1960...A. The Physical Review 57 (1940) pp.5 2 2 -5 2 7 Bloemnbergen. N. Proposalfior a new type solid state maser PhysicA Review 104 (1956) pp.3 2 4 -3 27...nrot ion of a lop Physica 18 (1952) pp.51i3 -51.. Braddon. F.D. Newitgyrosfor our 5ubmarines Journal of the Franklin Institute 270 (1960) p.7 9

  10. Gyroscopic stabilization and indefimite damped systems

    DEFF Research Database (Denmark)

    Pommer, Christian

    a class of feasibel skew-Hermitian matrices A depending on the choise of M. The theory can be applied to dynamical systems of the form x''(t) + ( dD + g G) x'(t) + K x(t) = 0 where G is a skew symmetric gyrocopic matrix, D is a symmetric indefinite damping matrix and K > 0 is a positive definite stiffness......An important issue is how to modify a given unstable matrix in such a way that the resulting matrix is stable. We investigate in general under which condition a matrix M+A is stable,where M is an arbitrary matrix and A is skew-Hermitian. We show that if trace(M) > 0 it is always possible to find...

  11. Theoretical Design of a Depolarized Interferometric Fiber-Optic Gyroscope (IFOG on SMF-28 Single-Mode Standard Optical Fiber Based on Closed-Loop Sinusoidal Phase Modulation with Serrodyne Feedback Phase Modulation Using Simulation Tools for Tactical and Industrial Grade Applications

    Directory of Open Access Journals (Sweden)

    Ramón José Pérez

    2016-04-01

    Full Text Available This article presents, by means of computational simulation tools, a full analysis and design of an Interferometric Fiber-Optic Gyroscope (IFOG prototype based on a closed-loop configuration with sinusoidal bias phase- modulation. The complete design of the different blocks, optical and electronic, is presented, including some novelties as the sinusoidal bias phase-modulation and the use of an integrator to generate the serrodyne phase-modulation signal. The paper includes detailed calculation of most parameter values, and the plots of the resulting signals obtained from simulation tools. The design is focused in the use of a standard single-mode optical fiber, allowing a cost competitive implementation compared to commercial IFOG, at the expense of reduced sensitivity. The design contains an IFOG model that accomplishes tactical and industrial grade applications (sensitivity ≤ 0.055 °/h. This design presents two important properties: (1 an optical subsystem with advanced conception: depolarization of the optical wave by means of Lyot depolarizers, which allows to use a sensing coil made by standard optical fiber, instead by polarization maintaining fiber, which supposes consequent cost savings and (2 a novel and simple electronic design that incorporates a linear analog integrator with reset in feedback chain, this integrator generating a serrodyne voltage-wave to apply to Phase-Modulator (PM, so that it will be obtained the interferometric phase cancellation. This particular feedback design with sawtooth-wave generated signal for a closed-loop configuration with sinusoidal bias phase modulation has not been reported till now in the scientific literature and supposes a considerable simplification with regard to previous designs based on similar configurations. The sensing coil consists of an 8 cm average diameter spool that contains 300 m of standard single-mode optical-fiber (SMF-28 type realized by quadrupolar winding. The working

  12. Theoretical Design of a Depolarized Interferometric Fiber-Optic Gyroscope (IFOG) on SMF-28 Single-Mode Standard Optical Fiber Based on Closed-Loop Sinusoidal Phase Modulation with Serrodyne Feedback Phase Modulation Using Simulation Tools for Tactical and Industrial Grade Applications.

    Science.gov (United States)

    Pérez, Ramón José; Álvarez, Ignacio; Enguita, José María

    2016-04-27

    This article presents, by means of computational simulation tools, a full analysis and design of an Interferometric Fiber-Optic Gyroscope (IFOG) prototype based on a closed-loop configuration with sinusoidal bias phase- modulation. The complete design of the different blocks, optical and electronic, is presented, including some novelties as the sinusoidal bias phase-modulation and the use of an integrator to generate the serrodyne phase-modulation signal. The paper includes detailed calculation of most parameter values, and the plots of the resulting signals obtained from simulation tools. The design is focused in the use of a standard single-mode optical fiber, allowing a cost competitive implementation compared to commercial IFOG, at the expense of reduced sensitivity. The design contains an IFOG model that accomplishes tactical and industrial grade applications (sensitivity ≤ 0.055 °/h). This design presents two important properties: (1) an optical subsystem with advanced conception: depolarization of the optical wave by means of Lyot depolarizers, which allows to use a sensing coil made by standard optical fiber, instead by polarization maintaining fiber, which supposes consequent cost savings and (2) a novel and simple electronic design that incorporates a linear analog integrator with reset in feedback chain, this integrator generating a serrodyne voltage-wave to apply to Phase-Modulator (PM), so that it will be obtained the interferometric phase cancellation. This particular feedback design with sawtooth-wave generated signal for a closed-loop configuration with sinusoidal bias phase modulation has not been reported till now in the scientific literature and supposes a considerable simplification with regard to previous designs based on similar configurations. The sensing coil consists of an 8 cm average diameter spool that contains 300 m of standard single-mode optical-fiber (SMF-28 type) realized by quadrupolar winding. The working wavelength will be

  13. Modification of piezoelectric vibratory gyroscope resonator parameters by feedback control

    CSIR Research Space (South Africa)

    Loveday, PW

    1998-09-01

    Full Text Available and labs with practical hands-on experience that will give them valuable experiences upon graduation. Another topic Dr. Rogers has made a priority is the introduction of engineering concepts into the science curriculum in the elementary schools. His belief... vibration modes have the same natural frequency, Manuscript received September 4, 1997; accepted December 18, 1997. P. W. Loveday is with Sensor Systems, Division of Material Science and Technology, CSIR, Pretoria, South Africa (e-mail: ploveday...

  14. Analysis of Acousto-Optic Errors in Laser Gyroscopes.

    Science.gov (United States)

    1982-12-01

    2 2 Sagnac’s Interferometer ................................ 4 3 Harress ’ Prism Ring.................................... 5 4...years before Sagnac’s experiment, Harress , a German graduate student formed a ring of partially reflecting prisms to measure the dispersive properties of...glass (Figure 3). Harress noticed a fringe shift when he rotated the ring, and he assumed that the shift was caused by the *dragging" of the light

  15. The rotational velocities evaluation for the engine mounts gyroscopic loads

    Directory of Open Access Journals (Sweden)

    Stefan BOGOS

    2013-06-01

    Full Text Available The default values for the maximum pitch and yaw speeds from CS 23.371, seem to be too conservative that would result in overstressing of the structure.A simplified dynamic simulation is proposed to evaluate more confident velocities for a specific aircraft. The yawing condition is related to the “sudden rudder deflection” and a maneuver with “lateral gust”. The pitching conditions are a result of a “sudden elevator deflection”. The model takes into account the nonlinear effects of the aerodynamic coefficients and controls efficiencies.

  16. Optimal Attitude Control of Agile Spacecraft Using Combined Reaction Wheel and Control Moment Gyroscope Arrays

    Science.gov (United States)

    2015-12-01

    communications between the MicroAuto Box and the ground station computer [58]. SimSat users design experiments in the MATLAB® Simulink environment and use an...Guidance, Control, and Dynamics, vol. 35, no. 4, pp. 1094–1103, 2012. [44] Z. Sun, L. Zhang, G. Jin, and X. Yang, “Analysis of inertia dyadic uncertainty

  17. Fast Light Enhanced Active Gyroscopes, Accelerometers and Fiber- Optic Sensors, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The fast-light effect, produced by anomalous dispersion, has emerged as a highly promising mechanism for enhancing the sensitivity of many devices. It is a...

  18. Basic Sensors in iOS Programming the Accelerometer, Gyroscope, and More

    CERN Document Server

    Allan, Alasdair

    2011-01-01

    What really sets the iPhone apart from laptops and PCs is its use of onboard sensors, including those that are location-enabled. This concise book takes experienced iPhone and Mac developers on a detailed tour of iPhone and iPad hardware by explaining how these sensors work, and what they're capable of doing. With this book, you'll build sample applications for each sensor, and learn hands-on how to take advantage of the data each sensor produces. You'll gain valuable experience that you can immediately put to work inside your own iOS applications for the iPhone, iPod touch, and iPad. This b

  19. A Comparison of Gyroscope Digital Models for an Electro-Optical/Infrared Guided Missile Simulation

    National Research Council Canada - National Science Library

    Waggoner, Brent

    2003-01-01

    This report was prepared by the author as a Master's thesis which partially fulfilled the requirements for a Master of Science degree in Electrical Engineering from Rose Hulman Institute of Technology, Terre Haute...

  20. From Gyroscopic to Thermal Motion: A Crossover in the Dynamics of Molecular Superrotors

    Directory of Open Access Journals (Sweden)

    A. A. Milner

    2015-09-01

    Full Text Available Localized heating of a gas by intense laser pulses leads to interesting acoustic, hydrodynamic, and optical effects with numerous applications in science and technology, including controlled wave guiding and remote atmosphere sensing. Rotational excitation of molecules can serve as the energy source for raising the gas temperature. Here, we study the dynamics of energy transfer from the molecular rotation to heat. By optically imaging a cloud of molecular superrotors, created with an optical centrifuge, we experimentally identify two separate and qualitatively different stages of its evolution. The first nonequilibrium “gyroscopic” stage is characterized by the modified optical properties of the centrifuged gas—its refractive index and optical birefringence, owing to the ultrafast directional molecular rotation, which survives tens of collisions. The loss of rotational directionality is found to overlap with the release of rotational energy to heat, which triggers the second stage of thermal expansion. The crossover between anisotropic rotational and isotropic thermal regimes is in agreement with recent theoretical predictions and our hydrodynamic calculations.

  1. A Novel Vacuum Packaging Design Process for Microelectromechanical System (MEMS) Quad-Mass Gyroscopes

    Science.gov (United States)

    2016-09-01

    resistance of one of the known legs can be fine-tuned to nullify gauge resistance perturbation and maintain a balanced bridge. Fig. 13 Die connections...efficient. From tanks and automobiles to unmanned aerial vehicles (UAVs) and robots , the need for improved performance is ubiquitous. Electronic... robots , munitions, and constrained vehicle platforms. Currently, the standard navigation system that the US military uses is GPS. However, one of the

  2. Innovative Fiber-Optic Gyroscopes (FOGs) for High Accuracy Space Applications, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — This project aims to develop a compact, highly innovative Inertial Reference/Measurement Unit (IRU/IMU) that pushes the state-of-the-art in high accuracy performance...

  3. Innovative Fiber-Optic Gyroscopes (FOGs) for High Accuracy Space Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA's future science and exploratory missions will require much lighter, smaller, and longer life rate sensors that can provide high accuracy navigational...

  4. Modelling of Influence of Hypersonic Conditions on Gyroscopic Inertial Navigation Sensor Suspension

    Directory of Open Access Journals (Sweden)

    Korobiichuk Igor

    2017-06-01

    Full Text Available The upcoming hypersonic technologies pose a difficult task for air navigation systems. The article presents a designed model of elastic interaction of penetrating acoustic radiation with flat isotropic suspension elements of an inertial navigation sensor in the operational conditions of hypersonic flight. It has been shown that the acoustic transparency effect in the form of a spatial-frequency resonance becomes possible with simultaneous manifestation of the wave coincidence condition in the acoustic field and equality of the natural oscillation frequency of a finite-size plate and a forced oscillation frequency of an infinite plate. The effect can lead to additional measurement errors of the navigation system. Using the model, the worst and best case suspension oscillation frequencies can be determined, which will help during the design of a navigation system.

  5. Low Cost Silicon Coriolis' Gyroscope Paves the Way to Consumer IMU

    Science.gov (United States)

    Vigna, Benedetto; Pasolini, Fabio; de Nuccio, Roberto; Capovilla, Macro; Prandi, Luciano; Biganzoli, Fabio

    During the last two years MEMS linear accelerometers have reinvented the way of playing a game, protecting your sensitive data on HDD, using your mobile devices smartly or making your washing machine less power hungry. Consumer and Industrial Markets have taken advantage from "The MEMS Consumerization Wave", driven by STMicroelectronics, which introduced a wide portfolio of two and three-axis motion sensors meeting customer requirements in terms of size, performances, quality and price.

  6. Prototyping and Characterization of an Adjustable Skew Angle Single Gimbal Control Moment Gyroscope

    Science.gov (United States)

    2015-03-01

    plates, two curved supports for the gimbal frame, and the box shaped mount base with the four roller rods basically carried through all further design... Underwood , “Experimental Testing of a CMG Cluster for Agile Microsatellites,” Journal-British Interplanetary Society, vol. 57, no. 9/10, pp. 318–324

  7. Gyroscopic effects in vibrating fluid-filled spheres subjected to inertial rotation

    CSIR Research Space (South Africa)

    Shatalov, MY

    2007-07-01

    Full Text Available belonging to the body (S). The absolute linear velocity of this point is ( ) cos cos sin sin u v V v u r w w v θ θ θ θ   − Ω  = + Ω + +     − Ω  ɺ arrowrightnosp ɺ ɺ (1) where r is the distance from the centre O... to the point P of the body ([1]). The kinetic energy of the system of concentric spherical bodies is approximately: ( ) ( ) ( ){ } 1 2 2 2 2 2 1 0 0 1 2 cos sin sin 2 i i aN i i i i i i i i i i i i i a K u v w u v u v v w v w r drd d pi pi ρ...

  8. Gyroscopic power take-off wave energy point absorber in irregular sea states

    DEFF Research Database (Denmark)

    Zhang, Zili; Chen, Bei; Nielsen, Søren R.K.

    2017-01-01

    Highlights •A GyroPTO wave energy point absorber with magnetic coupling mechanism is proposed. •A 4DOF nonlinear model of the GyroPTO absorber has been derived. •Rational approximations are performed on the radiation damping moments. •Synchronization of the device is more easily maintained...... in narrow-banded sea waves. •The generator gain and the magnetic coupling constant influence the performance of the device....

  9. Optical and magnetic measurements of gyroscopically stabilized graphene nanoplatelets levitated in an ion trap

    Science.gov (United States)

    Nagornykh, Pavel; Coppock, Joyce E.; Murphy, Jacob P. J.; Kane, B. E.

    2017-07-01

    Using optical measurements, we demonstrate that the rotation of micron-scale graphene nanoplatelets levitated in a quadrupole ion trap in high vacuum can be frequency-locked to an applied radiofrequency electric field Erf. Over time, frequency-locking stabilizes the nanoplatelet so that its axis of rotation is normal to the nanoplatelet and perpendicular to Erf. We observe that residual slow dynamics of the direction of the axis of rotation in the plane normal to Erf is determined by an applied magnetic field. We present a simple model that accurately describes our observations. From our data and model, we can infer both a diamagnetic polarizability and a magnetic moment proportional to the frequency of rotation, which we compare to theoretical values. Our results establish that trapping technologies have applications for materials measurements at the nanoscale.

  10. Angular Random Walk Estimation of a Time-Domain Switching Micromachined Gyroscope

    Science.gov (United States)

    2016-10-19

    angular random walk (ARW), bias instability, and scale factor instability. While there are methods to address issues with bias and scale factor...effects. Thus, it is expected that it will have low bias and scale factor instabilities. Simulated ARW performance of a particular incarnation of the...1 2. PARAMETRIC SYSTEM IDENTIFICATION BASED ON TIME-DOMAIN SWITCHING ........ 2 3. FINITE ELEMENT MODELING OF RESONATOR

  11. Miniaurizable, High Performance, Fiber-Optic Gyroscopes for Small Satellites, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase 2 program builds on a successful Phase 1 effort that demonstrated practical engineering methods as well as continuing development paths to build smaller...

  12. Ship Attitude Prediction Based on Input Delay Neural Network and Measurements of Gyroscopes

    DEFF Research Database (Denmark)

    Wang, Yunlong; N. Soltani, Mohsen; Hussain, Dil muhammed Akbar

    2017-01-01

    sampled in a ship simulation hardware system. Moreover, the factors that affect the prediction performance are also explored through a set of experiments. The prediction method proposed can achieve high precision, that is, the root-mean-square prediction errors for roll, pitch and yaw, are 0.26 deg, 0...

  13. GINGER (Gyroscopes IN General Relativity), a ring lasers array to measure the Lense-Thirring effect

    Science.gov (United States)

    Di Virgilio, Angela D. V.

    The purpose of the GINGER is to perform the first test of general relativity (not considering the gravitational redshift measurements) in a terrestrial laboratory, using light as a probe. The experiment will complement the ones in space, performed or under way, with an entirely different technique and at a far lower cost. The methodology is based on ring-lasers, which are extremely accurate rotation sensors and can not only sense purely kinematical rotations (Sagnac effect accounting for the Earth rotation, polar motion of the terrestrial axis, local rotational movements of the laboratory due to the Earth crust dynamics...), but also general relativistic contributions such as the de Sitter effect (coupling between the gravito-electric field of the earth and the kinematical rotation) and the Lense-Thirring effect (inertial frame dragging due to the angular momentum of the earth). In order to reveal the latter effects, ring-laser response must be improved to be able to measure the effective rotation vector (kinematic plus GR terms) with an accuracy of 1 part in 109 or better. This is a challenging technological aspect, which however has been accurately taken into account by designing a system of ring lasers that will be implemented in this project. A ring laser have been installed inside the underground laboratory of GranSasso, with the purpose to see if an underground location is the right choice for GINGER. The apparatus and the preliminary results will be discussed.

  14. Corrosion resistance of the substrates for the cryogenic gyroscope and electrodeposition of the superconductive niobium coatings

    Science.gov (United States)

    Dubrovskiy, A. R.; Okunev, M. A.; Makarova, O. V.; Kuznetsov, S. A.

    2017-05-01

    The interaction of different materials with the niobium containing melt was investigated. As substrate materials the ceramics, beryllium and carbopyroceram were chosen. Several spherical ceramic and beryllium samples were coated with protective molybdenum and niobium films by magnetron sputtering and PVD, respectively. After the experiment (exposition time 10 min) the exfoliation of molybdenum film from ceramic samples was observed due to interaction of the substrate with the melt. The niobium protective coatings reacted with the melt with niobium oxide formation. The beryllium samples regardless of the shape and the presence of the protective films were dissolved in the niobium containing melt due to more negative electrode potential comparing with niobium one. The carbopyroceram samples were exposed in the melt during 3 and 12 h. It was found that the carbopyroceram not corrodes in the niobium containing melt. The optimal regimes for electrodeposition of smooth uniform niobium coatings with the thickness up to 50 μm on carbopyroceram spheres were found.

  15. Bifurcations of Eigenvalues of Gyroscopic Systems with Parameters Near Stability Boundaries

    DEFF Research Database (Denmark)

    Seyranian, Alexander P.; Kliem, Wolfhard

    1999-01-01

    , as well as first derivatives of the system matrices (or operators) with respect to parameters. These results provide simple and constructive stability and instability criteria. The presented theory is exemplified by two mechanical problems: a rotating elastic shaft carrying a disk, and an axially moving...

  16. On gyroscopic effects in vibrating and axially rotating solid and annular discs

    CSIR Research Space (South Africa)

    Joubert, SV

    2007-05-01

    Full Text Available are negligible. Our model is formulated in general terms and then compared to a formulation in terms of Novozhilov-Arnold-Warbur-ton’s theory of thin shells. The system of equations of motion of the disc is separated and transformed into a pair of wave equations...

  17. Investigation of gyroscopic effects in vibrating fluid-filled cylinders subjected to axial rotation

    CSIR Research Space (South Africa)

    Shatalov, MY

    2007-07-01

    Full Text Available , according to him, showed that nodes revolve at an angular rate different from that of the shell. He then attempted to quantify this difference in angular rate by a quantity known as Bryan's factor. Faraday [2], Spurr [3] and Apfel [4] discussed similar...", Proceedings of the Cambridge Philosophical Society for Mathematical and Physical Sciences 7,101- 111 (1890). [2] M. Faraday, "On a peculiar class of acoustical figures and on certain forms assumed by groups of particles upon vibrating elastic surfaces...

  18. Design and analysis of power supply and information transfer to three-axis gyroscope stabilizer platform

    Directory of Open Access Journals (Sweden)

    Belyanin Lev

    2016-01-01

    Full Text Available The paper focuses on problems of the engineering implementation of 3-axis gyrostabilizer of the camera for orthophotography performed from light and ultralight aircrafts. The functional diagram of gyrostabilizer is characterized by a lighter ball-bearing having a large inner diameter used for the platform suspension on its internal (vertical axis. The problem is to transfer the supply voltage to the platform and the electric signals to and from the platform. Design solutions concerning the power supply and information transfer are supported by the experimental techniques suggested in this paper, namely: the use of the rolling contact; three-phase gyro motor power supply replaced by that from the single-phase network; signal transmission from the precession angle sensor using the air transformer; current and voltage frequency division; DC mode selection for the torquer. The results obtained prove the efficiency of the suggested design solutions.

  19. Miniaurizable, High Performance, Fiber-Optic Gyroscopes for Small Satellites, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Small satellites require much lighter weight, smaller, and long life Attitude control components that can withstand stressing launch conditions and space vibration...

  20. Two calibration procedures for a gyroscope-free inertial measurement system based on a double-pendulum apparatus

    Science.gov (United States)

    Cappa, P.; Patanè, F.; Rossi, S.

    2008-05-01

    This paper presents a novel calibration algorithm to be used with a gyro-free inertial measurement unit (GF-IMU) based on the use of linear accelerometers (AC). The analytical approach can be implemented in two calibration procedures. The first procedure (P-I) is articulated in the conduction of a static trial, to compute the sensitivity and the direction of the sensing axis of each AC, followed by a dynamic trial, to determine the AC locations. By contrast, the latter procedure (P-II) consists in the calculation of the previously indicated calibration parameters by means of a dynamic trial only. The feasibility of the two calibration procedures has been investigated by testing two GF-IMUs, equipped with ten and six bi-axial linear ACs, with an ad hoc instrumented double-pendulum apparatus. P-I and P-II were compared to a calibration procedure used as a reference (P-REF), which incorporates the AC positions measured with an optoelectronic system. The experimental results we present in this paper demonstrate that (i) P-I is able to determine the calibration parameters of the AC array with a higher accuracy than P-II; (ii) consequently, the errors associated with translational (a0 - g) and rotational (\\dot{\\bm \\omega }) acceleration components for the two GF-IMUs are significantly greater using P-II than P-I and (iii) the errors in (a0 - g) and \\dot{\\bm \\omega } obtained with P-I are comparable with the ones obtainable by using P-REF. Thus, the proposed novel algorithm used in P-I, in conjunction with the double-pendulum apparatus, can be globally considered a viable tool in GF-IMU calibration.

  1. Development of a Hardware-in-the-Loop Simulator for Control Moment Gyroscope-Based Attitude Control Systems

    Science.gov (United States)

    2015-12-01

    Leon, Linear Algebra with Applications, 5th ed., Upper Saddle River, NJ: Prentice Hall, 2009. [25] Controller Area Network (CAN) Tutorial, National...as an elementary rotation when it is about a single principal axis in the reference frame. When successive rotations are implemented, a numerical...axis). The DCMs for elementary rotations are as follows [4]:  1 1 1 1 1 1 1 0 0 0 cos sin 0 sin cos C             (8)   22 122

  2. Study of the fusion point between PM-PCF and panda fiber and its influence to Interferometric fiber-optical gyroscope

    Science.gov (United States)

    Sun, Zuoming; Wang, Shuhua; Li, Junwei

    2017-02-01

    Microhole collapse property of polarization maintaining photonic crystal fibers (PM-PCF) and its effect on the splice loss and polarization cross-coupling during fusion splicing were investigated. The relationship between the microhole collapse and polarization cross-coupling are analyzed through simulation and experiment. Finally their influence to the phase error of the FOG is calculated and tested.

  3. Very high precision survey equipment for great distances Surface surveys used to map out the surface network and the tunnelling machines then gyroscopically steered underground.

    CERN Document Server

    1983-01-01

    At the beginning of the 1980s, CERN embarked on the enormous Large Electron-Positron Collider construction project. The excavation of the 27-kilometre LEP tunnel was a huge technical challenge. The tunnel-boring machines excavated the tunnel in 3.3 km octants and had to be operated with extraordinary precision to ensure that they reached their destination - the bottom of the next vertical shaft - precisely on target. The tunnel was excavated before high-performance instruments were developed for the construction of the Channel Tunnel. As no firms were willing to perform the surveying work, CERN's own surveyors, with experience from the SPS behind them, took up the challenge. At the surface, the surveyors established the world's most accurate geodetic network, performing measurements to an accuracy of 10-7, or 1mm per 10 km, using the Terrameter (see photo). The excavation of the tunnel was completed in 1988 and the finished tunnel's trajectory was found to diverge from the theoretical value specified by the p...

  4. Averaged Propulsive Body Acceleration (APBA) Can Be Calculated from Biologging Tags That Incorporate Gyroscopes and Accelerometers to Estimate Swimming Speed, Hydrodynamic Drag and Energy Expenditure for Steller Sea Lions

    OpenAIRE

    Ware, Colin; Trites, Andrew W.; Rosen, David A. S.; Potvin, Jean

    2016-01-01

    Forces due to propulsion should approximate forces due to hydrodynamic drag for animals horizontally swimming at a constant speed with negligible buoyancy forces. Propulsive forces should also correlate with energy expenditures associated with locomotion-an important cost of foraging. As such, biologging tags containing accelerometers are being used to generate proxies for animal energy expenditures despite being unable to distinguish rotational movements from linear movements. However, recen...

  5. Low Cost, Vacuum Packaging of GN&C Sensors, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Micro-electro-mechanical System (MEMS)-based gyroscopes, accelerometers and rate sensors are essential to miniaturizing the guidance, navigation and control...

  6. The prototype design of the Stanford Relativity Gyro Experiment

    Science.gov (United States)

    Parkinson, Bradford W.; Everitt, C. W. Francis; Turneaure, John P.; Parmley, Richard T.

    1987-01-01

    The Stanford Relativity Gyroscope Experiment constitutes a fundamental test of Einstein's General Theory of Relativity, probing such heretofore untested aspects of the theory as those that relate to spin by means of drag-free satellite-borne gyroscopes. General Relativity's prediction of two orthogonal precessions (motional and geodetic) for a perfect Newtonian gyroscope in polar orbit has not yet been experimentally assessed, and will mark a significant advancement in experimental gravitation. The technology employed in the experiment has been under development for 25 years at NASA's Marshall Space Flight Center. Four fused quartz gyroscopes will be used.

  7. Micromachined Precision Inertial Instruments

    National Research Council Canada - National Science Library

    Najafi, Khalil

    2003-01-01

    This program focuses on developing inertial-grade micromachined accelerometers and gyroscopes and their associated electronics and packaging for use in a variety of military and commercial applications...

  8. A Hamiltonian approach to model and analyse networks of ...

    Indian Academy of Sciences (India)

    2015-09-24

    Sep 24, 2015 ... Gyroscopes; energy harvesters; synchronization; Hamiltonian mechanics. ... ideas and methods from nonlinear dynamics system theory, in particular, ... deploy highly sensitive, lowpower, magnetic and electric field sensors.

  9. High precision estimation of inertial rotation via the extended Kalman filter

    Science.gov (United States)

    Liu, Lijun; Qi, Bo; Cheng, Shuming; Xi, Zairong

    2015-11-01

    Recent developments in technology have enabled atomic gyroscopes to become the most sensitive inertial sensors. Atomic spin gyroscopes essentially output an estimate of the inertial rotation rate to be measured. In this paper, we present a simple yet efficient estimation method, the extended Kalman filter (EKF), for the atomic spin gyroscope. Numerical results show that the EKF method is much more accurate than the steady-state estimation method, which is used in the most sensitive atomic gyroscopes at present. Specifically, the root-mean-squared errors obtained by the EKF method are at least 103 times smaller than those obtained by the steady-state estimation method under the same response time.

  10. An Integrated Thermal Compensation System for MEMS Inertial Sensors

    Directory of Open Access Journals (Sweden)

    Sheng-Ren Chiu

    2014-03-01

    Full Text Available An active thermal compensation system for a low temperature-bias-drift (TBD MEMS-based gyroscope is proposed in this study. First, a micro-gyroscope is fabricated by a high-aspect-ratio silicon-on-glass (SOG process and vacuum packaged by glass frit bonding. Moreover, a drive/readout ASIC, implemented by the 0.25 µm 1P5M standard CMOS process, is designed and integrated with the gyroscope by directly wire bonding. Then, since the temperature effect is one of the critical issues in the high performance gyroscope applications, the temperature-dependent characteristics of the micro-gyroscope are discussed. Furthermore, to compensate the TBD of the micro-gyroscope, a thermal compensation system is proposed and integrated in the aforementioned ASIC to actively tune the parameters in the digital trimming mechanism, which is designed in the readout ASIC. Finally, some experimental results demonstrate that the TBD of the micro-gyroscope can be compensated effectively by the proposed compensation system.

  11. Symposium Gyro Technology 1997

    Energy Technology Data Exchange (ETDEWEB)

    Sorg, H [ed.; Stuttgart Univ. (Germany). Inst. A fuer Mechanik

    1997-10-01

    This volume includes the twenty papers which were presented at the Symposium Gyro Technology 1997. The subjects that have been treated during the symposium were as follows: Performance and design of silicon micromachined gyro; improved rate gyroscope designs designated for fabrication by modern deep silicon etching; micromechanical vibratory rate gyroscopes fabricated in conventional CMOS; error modelling of silicon angular rate sensor; a capacitive accelerometer as an example for surface micromachined inertial sensors; initial production results of a new family of fiber optic gyroscopes; dual-axis multiplexed open loop fiber optic gyroscope; flattely supported vibratory gyro-sensor using a Trident-type tuning fork resonator; innovative mechanizations to optimize inertial sensors for high or low rate operations; design of a planar vibratory gyroscope using electrostatic actuation and electromanetic detection; fiber optic gyro based land navigation system; FOG AHRS and AHRS/GPS navigation system: the low cost solution; GPS/GLONASS/INS-navigation (GLOGINAV); small-sized integrated system of the sea mobile objects attitude and navigation; concepts for hybrid positioning; preliminary results from a large ring laser gyroscope for fundamental physics and geophysics; a `sense of balance` - AHRS with low-cost vibrating-gyroscopes for medical diagnostics; application of strapdown inertial systems of orientation and navigation in intrapipe moving diagnostic apparatus; investigation of a digital readout system for laser gyro; the use of angular rate multiple integrals as input signals for strapdown attitude algorithms. (AKF)

  12. INERTIAL TECHNOLOGIES IN SYSTEMS FOR STABILIZATION OF GROUND VEHICLES EQUIPMENT

    Directory of Open Access Journals (Sweden)

    Olha Sushchenko

    2016-12-01

    Full Text Available Purpose: The vibratory inertial technology is a recent modern inertial technology. It represents the most perspective approach to design of inertial sensors, which can be used in stabilization and tracking systems operated on vehicles of the wide class. The purpose of the research is to consider advantages of this technology in comparison with laser and fiber-optic ones. Operation of the inertial sensors on the ground vehicles requires some improvement of the Coriolis vibratory gyroscope with the goal to simplify information processing, increase reliability, and compensate bias. Methods: Improvement of the Coriolis vibratory gyroscope includes introducing of the phase detector and additional excitation unit. The possibility to use the improved Coriolis vibratory gyroscope in the stabilization systems operated on the ground vehicles is shown by means of analysis of gyroscope output signal. To prove efficiency of the Coriolis vibratory gyroscope in stabilization system the simulation technique is used. Results: The scheme of the improved Coriolis vibratory gyroscope including the phase detector and additional excitation unit is developed and analyzed. The way to compensate bias is determined. Simulation of the stabilization system with the improved Coriolis vibratory gyroscope is carried out. Expressions for the output signals of the improved Coriolis vibratory gyroscope are derived. The error of the output signal is estimated and the possibility to use the modified Coriolis vibratory gyroscope in stabilization systems is proved. The results of stabilization system simulation are given. Their analysis is carried out. Conclusions: The represented results prove efficiency of the proposed technical decisions. They can be useful for design of stabilization platform with instrumental equipment operated on moving vehicles of the wide class.

  13. The Weyl non-Abelian gauge field and the Thomas precession

    International Nuclear Information System (INIS)

    Barbashov, B.M.; Pestov, A.B.

    1998-01-01

    The connection between the Fermi-Walker transport and the Weyl non-Abelian gauge field is established. A theoretical possibility of detecting the Weyl gauge field caused by the Thomas precession of a gyroscope is discussed

  14. A Low-Cost, High-Precision Navigator, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Toyon Research Corporation proposes to develop and demonstrate a prototype low-cost precision navigation system using commercial-grade gyroscopes and accelerometers....

  15. A wearable 3D motion sensing system integrated with a Bluetooth smart phone application: A system level overview

    KAUST Repository

    Karimi, Muhammad Akram; Shamim, Atif

    2018-01-01

    description of a wearable 3D motion sensor. The sensing mechanism is based upon well-established magnetic and inertial measurement unit (MIMU), which integrates accelerometer, gyroscope and magnetometer data. Two sensor boards have been integrated within a

  16. Smartphone-based solutions to monitor and reduce fuel consumption and CO2 footprint : final report.

    Science.gov (United States)

    2016-06-01

    Smartphones equipped with GPS and several low-energy sensors (e.g., gyroscope, compass, and accelerometer) can provide a medium to collect probe data. As smartphone users navigate the transportation networks, their travel modes and trajectories can b...

  17. A Comparative Study of All-Accelerometer Strapdowns for UAV INS

    National Research Council Canada - National Science Library

    Cardou, Philippe; Angeles, Jorge

    2005-01-01

    ...) for Unmanned Aerial Vehicles (UAV). Benefiting from the fabrication processes of MEMS technologies, accelerometers now offer several advantages over gyroscopes, such as low weight, compactness, high reliability and low cost, for example...

  18. Apparatus, system, and method for traffic monitoring

    KAUST Repository

    Claudel, Christian G.; Mousa, Mustafa; Abdulaal, Mohammed

    2016-01-01

    An apparatus, system, and method for traffic monitory can have a Lagrangian inertial measurement unit. The Lagrangian inertial measurement unit can have a processor, an accelerometer, a gyroscope, and/or a wireless transmitter. The processor can

  19. MEMS mass-spring-damper systems using an out-of-plane suspension scheme

    KAUST Repository

    Abdel Aziz, Ahmed Kamal Said; Sharaf, Abdel Hameed; Serry, Mohamed Yousef; Sedky, Sherif Salah

    2014-01-01

    MEMS mass-spring-damper systems (including MEMS gyroscopes and accelerometers) using an out-of-plane (or vertical) suspension scheme, wherein the suspensions are normal to the proof mass, are disclosed. Such out-of-plane suspension scheme helps such MEMS mass-spring-damper systems achieve inertial grade performance. Methods of fabricating out-of-plane suspensions in MEMS mass-spring-damper systems (including MEMS gyroscopes and accelerometers) are also disclosed.

  20. MEMS mass-spring-damper systems using an out-of-plane suspension scheme

    KAUST Repository

    Abdel Aziz, Ahmed Kamal Said

    2014-02-04

    MEMS mass-spring-damper systems (including MEMS gyroscopes and accelerometers) using an out-of-plane (or vertical) suspension scheme, wherein the suspensions are normal to the proof mass, are disclosed. Such out-of-plane suspension scheme helps such MEMS mass-spring-damper systems achieve inertial grade performance. Methods of fabricating out-of-plane suspensions in MEMS mass-spring-damper systems (including MEMS gyroscopes and accelerometers) are also disclosed.

  1. 155-mm M795 Aerofuze Test at the KOFA Range, Yuma Proving Ground, Arizona, 19 May 2015

    Science.gov (United States)

    2017-09-01

    the high -g accelerometers during flight Low-g Accelerometer (ADXL377) Low-G accelerometer data is available and was clean and complete throughout...temperature during flight High -rate Gyroscopes (3X ADXRS649) Data from the high -rate gyroscopes were available during the entire flight with no...Picatinny Arsenal, New Jersey UNCLASSIFIED UNCLASSIFIED The views, opinions, and/or findings contained in this report

  2. A Personal Inertial Navigation System Based on Multiple Distributed, Nine-Degrees-Of-Freedom, Inertial Measurement Units

    Science.gov (United States)

    2016-12-01

    the gyroscope to calculate position changes during the swing phase, it is important to identify and take steps to mitigate these major error types [11...holding a constant bias, flicker noise causes the error bias to randomly wander within a bounded area. For example, if the gyroscope was stationary and...39]. Flicker noise is the cause of error bias stability issues and is dominant at low frequencies where the power of its degrading effects can be

  3. Modeling of micro thrusters for gravity probe B

    Science.gov (United States)

    Jones, Kenneth M.

    1996-01-01

    The concept of testing Einstein's general theory of relativity by means of orbiting gyroscopes was first proposed in 1959, which lead to the development of the Gravity Probe B experiment. Einstein's theory concerns the predictions of the relativistic precession of a gyroscope in orbit around earth. According to his theory, there will be two precessions due to the warping of space-time by the earth's gravitational field: the geodetic precession in the plane of the orbit, and the frame-dragging effect, in the direction of earth rotation. For a polar orbit, these components are orthogonal. In order to simplify the measurement of the precessions, Gravity Probe B (GP-B) will be placed in a circular polar orbit at 650 km, for which the predicted precessions will be 6.6 arcsec/year (geodetic) and 42 milli-arcsec/year (frame-dragging). As the gyroscope precesses, the orientation of its spin-axis will be measured with respect to the line-of-sight to Rigel, a star whose proper motion is known to be within the required accuracy. The line-of-sight to Rigel will be established using a telescope, and the orientation of the gyroscope spin axis will be measured using very sensitive SQUID (Superconducting Quantum Interference Device) magnetometers. The four gyroscopes will be coated with niobium. Below 2K, the niobium becomes superconducting and a dipole field will be generated which is precisely aligned with the gyroscope spin-axis. The change in orientation of these fields, as well as the spin-axis, is sensed by the SQUID magnetometers. In order to attain the superconducting temperatures for the gyroscopes and the SQUID's, the experiment package will be housed in a dewar filled with liquid helium. The helium flow through a GP-B micro thruster and into a vacuum is investigated using the Direct Simulation Monte Carlo method.

  4. Emerging technologies in microguidance and control

    Science.gov (United States)

    Weinberg, Marc S.

    1993-01-01

    Employing recent advances in microfabrication, the Charles Stark Draper Laboratory has developed inertial guidance instruments of very small size and low cost. Microfabrication employs the batch processing techniques of solid state electronics, such as photolithography, diffusion, and etching, to carve mechanical parts. Within a few years, microfabricated gyroscopes should perform in the 10 to 100 deg/h range. Microfabricated accelerometers have demonstrated performance in the 50 to 500 microgravity range. These instruments will result in not only the redesign of conventional military products, but also new applications that could not exist without small, inexpensive sensors and computing. Draper's microfabricated accelerometers and gyroscopes will be described and test results summarized. Associated electronics and control issues will also be addressed. Gimballed, vibrating gyroscopes and force rebalance accelerometers constructed from bulk silicon, polysilicon surface-machined tuning fork gyroscopes, and quartz resonant accelerometers and gyroscopes are examined. Draper is pursuing several types of devices for the following reasons: to address wide ranges of performance, to realize construction in a flat pack, and to lessen the risks associated with emerging technologies.

  5. Gradiometry coexperiments to the gravity probe B and step missions

    International Nuclear Information System (INIS)

    Tapley, M.; Breakwell, J.; Everitt, C.W.F.; Vanpatten, R.; Worden, P.

    1990-01-01

    The Gravity Probe-B (GP-B) spacecraft, designed to test predictions of general relativity, will fly in the mid 1990s. It will carry four electrostatically suspended gyroscopes in a cryogenic environment and will have a drag-free control system to minimize disturbances on the gyroscopes. The Stanford Test of Equivalence Principle (STEP) spacecraft, to fly later, will carry a set of test masses under very similar conditions. The possibility of using differential measurements of the GP-B gyroscopes suspension forces and the STEP tests mass displacement readout to form single-axis gravity gradiometers is explored. It is shown that the noise in the suspension systems is sufficiently small in the relevant frequency range, and that enough information is collected to compensate for the spacecrafts' attitude motion. Finally, using Breakwell's flat-earth approximation, these experiments are compared to other geodesy experiments and predict the contribution they can make to the knowledge of the Earth's geopotential

  6. Analog integrated circuit for micro-gyro interface realized by multi-chip service in Japan; Multi chip service ni yoru micro gyro interface shuseki kairo no sekkei to shisaku

    Energy Technology Data Exchange (ETDEWEB)

    Maenaka, K.; Fujita, T.; Okamoto, K.; Maeda, M. [Himeji Institute of Technology, Hyogo (Japan)

    1998-10-01

    This paper deals with an analog integrated circuit for micro-machined gyroscopes with capacitive output. The Integrated circuit was fabricated as a part of the first project from the `Micromachining Multi-Chip Service Cooperative Re-search Committee` organized by The Institute of Electrical Engineers Japan. This multi-chip service project offers a master slice chip with an equivalent of 9 blocks of operational amplifier circuits. Our integrated circuit includes a modulator, demodulator and synchronous rectifier for detecting small changes in the capacitance of a silicon gyroscope. In the paper, the experimental results of fabricated samples will be described. 13 refs., 15 figs.

  7. The Magnus problem in Rodrigues-Hamilton parameters

    Science.gov (United States)

    Koshliakov, V. N.

    1984-04-01

    The formalism of Rodrigues-Hamilton parameters is applied to the Magnus problem related to the systematic drift of a gimbal-mounted astatic gyroscope due to the nutational vibration of the main axis of the rotor. It is shown that the use of the above formalism makes it possible to limit the analysis to a consideration of a linear system of differential equations written in perturbed values of Rodrigues-Hamilton parameters. A refined formula for the drift of the main axis of the gyroscope rotor is obtained, and an estimation is made of the effect of the truncation of higher-order terms.

  8. Inertial Sea Wave Energy Converter from Mediterranean Sea to Ocean - Design Optimization

    Science.gov (United States)

    Calleri, Marco

    Optimization of the number of gyroscopes and flywheel rotational speed of a Wave Energy Converter able to produce 725 kW as the nominal power, in the chosen installation site, respecting some imposed constraints and some dimensions from the previous design, by minimizing the cost of the device and the bearing power losses, through the minimization of the LCOE of the device.

  9. Fulltext PDF

    Indian Academy of Sciences (India)

    picture this, recall what happens when a spinning top or gyroscope is placed in a ..... The hippocampus plays a role in long term memory stor- age while the ... use Spanish and English words to name the same ob- ject. The study shows that ...

  10. A feedback linearization approach to spacecraft control using momentum exchange devices. Ph.D. Thesis

    Science.gov (United States)

    Dzielski, John Edward

    1988-01-01

    Recent developments in the area of nonlinear control theory have shown how coordiante changes in the state and input spaces can be used with nonlinear feedback to transform certain nonlinear ordinary differential equations into equivalent linear equations. These feedback linearization techniques are applied to resolve two problems arising in the control of spacecraft equipped with control moment gyroscopes (CMGs). The first application involves the computation of rate commands for the gimbals that rotate the individual gyroscopes to produce commanded torques on the spacecraft. The second application is to the long-term management of stored momentum in the system of control moment gyroscopes using environmental torques acting on the vehicle. An approach to distributing control effort among a group of redundant actuators is described that uses feedback linearization techniques to parameterize sets of controls which influence a specified subsystem in a desired way. The approach is adapted for use in spacecraft control with double-gimballed gyroscopes to produce an algorithm that avoids problematic gimbal configurations by approximating sets of gimbal rates that drive CMG rotors into desirable configurations. The momentum management problem is stated as a trajectory optimization problem with a nonlinear dynamical constraint. Feedback linearization and collocation are used to transform this problem into an unconstrainted nonlinear program. The approach to trajectory optimization is fast and robust. A number of examples are presented showing applications to the proposed NASA space station.

  11. Inertial and magnetic sensing of human movement near ferromagnetic materials

    NARCIS (Netherlands)

    Roetenberg, D.; Luinge, Hendrik J.; Veltink, Petrus H.

    2003-01-01

    This paper describes a Kalman filter design to estimate orientation of human body segments by fusing gyroscope, accelerometer and magnetometer signals. Ferromagnetic materials near the sensor disturb the local magnetic field and therefore the orientation estimation. The magnetic disturbance can be

  12. A Framework for Designing Collaborative Learning Environments Using Mobile AR

    Science.gov (United States)

    Cochrane, Thomas; Narayan, Vickel; Antonczak, Laurent

    2016-01-01

    Smartphones provide a powerful platform for augmented reality (AR). Using a smartphone's camera together with the built in GPS, compass, gyroscope, and touch screen enables the real world environment to be overlaid with contextual digital information. The creation of mobile AR environments is relatively simple, with the development of mobile AR…

  13. Berkeley Experiments on Superfluid Macroscopic Quantum Effects

    International Nuclear Information System (INIS)

    Packard, Richard

    2006-01-01

    This paper provides a brief history of the evolution of the Berkeley experiments on macroscopic quantum effects in superfluid helium. The narrative follows the evolution of the experiments proceeding from the detection of single vortex lines to vortex photography to quantized circulation in 3He to Josephson effects and superfluid gyroscopes in both 4He and 3He

  14. The Gravity Probe B experiment and early results

    Energy Technology Data Exchange (ETDEWEB)

    Conklin, John W [Stanford University (United States)], E-mail: johnwc@stanford.edu

    2008-11-01

    The NASA Gravity Probe B orbiting gyroscope test of General Relativity, launched from Vandenberg Air Force Base on 20 April, 2004 tests two consequences of Einstein's theory: 1) the predicted 6.6 arcs/yr geodetic effect due to the motion of the gyroscope through the curved space-time around the Earth; 2) the predicted 0.039 arcs/yr frame-dragging effect due to the rotating Earth. The mission required the development of many technologies that did not exist when experiment was conceived in 1960. Cryogenic gyroscopes with drift-rates 7 orders of magnitude better than the best inertial navigation gyroscopes, a < 1 marcs star tracking telescope, and other essential technologies were developed as a result of an intensive collaboration between Stanford physicists and engineers, NASA and industry. Gravity Probe B collected science data from August 27, 2004 through September 29, 2005. Analysis of the data began during the mission and is on-going. This paper describes the main features and challenges of the experiment and presents the preliminary results to date.

  15. The Gravity Probe B experiment and early results

    International Nuclear Information System (INIS)

    Conklin, John W

    2008-01-01

    The NASA Gravity Probe B orbiting gyroscope test of General Relativity, launched from Vandenberg Air Force Base on 20 April, 2004 tests two consequences of Einstein's theory: 1) the predicted 6.6 arcs/yr geodetic effect due to the motion of the gyroscope through the curved space-time around the Earth; 2) the predicted 0.039 arcs/yr frame-dragging effect due to the rotating Earth. The mission required the development of many technologies that did not exist when experiment was conceived in 1960. Cryogenic gyroscopes with drift-rates 7 orders of magnitude better than the best inertial navigation gyroscopes, a < 1 marcs star tracking telescope, and other essential technologies were developed as a result of an intensive collaboration between Stanford physicists and engineers, NASA and industry. Gravity Probe B collected science data from August 27, 2004 through September 29, 2005. Analysis of the data began during the mission and is on-going. This paper describes the main features and challenges of the experiment and presents the preliminary results to date.

  16. KSC-04PD-0940

    Science.gov (United States)

    2004-01-01

    KENNEDY SPACE CENTER, FLA. The Gravity Probe B spacecraft, atop a Boeing Delta II vehicle, launches at 12:57:24 p.m. EDT from Space Launch Complex 2 at Vandenberg Air Force Base, Calif. Gravity Probe B is the relativity gyroscope experiment being developed by NASA and Stanford University to test two extraordinary, unverified predictions of Albert Einstein's general theory of relativity.

  17. Radiation hardening commercial off-the-shelf erbium doped fibers by optimal photo-annealing source

    Science.gov (United States)

    Peng, Tz-Shiuan; Liu, Ren-Young; Lin, Yen-Chih; Mao, Ming-Hua; Wang, Lon A.

    2017-09-01

    Erbium doped fibers (EDFs) based devices are widely employed in space for optical communication [1], remote sensing [2], and navigation applications, e.g. interferometric fiber optic gyroscope (IFOG). However, the EDF suffers severely radiation induced attenuation (RIA) in radiation environments, e.g. space applications and nuclear reactors [3].

  18. Discrimination Between Child and Adult Forms Using Radar Frequency Signature Analysis

    Science.gov (United States)

    2013-03-14

    karma,” specifically mine , but, despite all that, we were able to bring the project to a successful conclusion. It was not, however, without the help of... Opal , Portland OR). The wireless inertial sensors measure orientation using a combination of accelerometers, gyroscopes, and magnetometers. Neither

  19. Virtual Proprioception for eccentric training.

    Science.gov (United States)

    LeMoyne, Robert; Mastroianni, Timothy

    2017-07-01

    Wireless inertial sensors enable quantified feedback, which can be applied to evaluate the efficacy of therapy and rehabilitation. In particular eccentric training promotes a beneficial rehabilitation and strength training strategy. Virtual Proprioception for eccentric training applies real-time feedback from a wireless gyroscope platform enabled through a software application for a smartphone. Virtual Proprioception for eccentric training is applied to the eccentric phase of a biceps brachii strength training and contrasted to a biceps brachii strength training scenario without feedback. During the operation of Virtual Proprioception for eccentric training the intent is to not exceed a prescribed gyroscope signal threshold based on the real-time presentation of the gyroscope signal, in order to promote the eccentric aspect of the strength training endeavor. The experimental trial data is transmitted wireless through connectivity to the Internet as an email attachment for remote post-processing. A feature set is derived from the gyroscope signal for machine learning classification of the two scenarios of Virtual Proprioception real-time feedback for eccentric training and eccentric training without feedback. Considerable classification accuracy is achieved through the application of a multilayer perceptron neural network for distinguishing between the Virtual Proprioception real-time feedback for eccentric training and eccentric training without feedback.

  20. Angular Momentum

    Science.gov (United States)

    Shakur, Asif; Sinatra, Taylor

    2013-01-01

    The gyroscope in a smartphone was employed in a physics laboratory setting to verify the conservation of angular momentum and the nonconservation of rotational kinetic energy. As is well-known, smartphones are ubiquitous on college campuses. These devices have a panoply of built-in sensors. This creates a unique opportunity for a new paradigm in…

  1. Toys in space

    Science.gov (United States)

    1985-01-01

    The pictured toys will be carried aboard the Challenger on the STS 51-D mission as part of a study of physics in cooperation with the Houston Museum of Natural Sciences. The toys include a yoyo, paddleball, friction powered toy car, flipping mouse, top, ball and jacks, gyroscopes, Slinky and Wheelo.

  2. The Dynamics of Finite-Dimensional Systems Under Nonconservative Position Forces

    Science.gov (United States)

    Lobas, L. G.

    2001-01-01

    General theorems on the stability of stationary states of mechanical systems subjected to nonconservative position forces are presented. Specific mechanical problems on gyroscopic systems, a double-link pendulum with a follower force and elastically fixed upper tip, multilink pneumowheel vehicles, a monorail car, and rail-guided vehicles are analyzed. Methods for investigation of divergent bifurcations and catastrophes of stationary states are described

  3. Features of course definition system control for a mode of preliminary bringing to horizon

    Directory of Open Access Journals (Sweden)

    О.А. Сущенко

    2004-03-01

    Full Text Available  The features of course definition system consisting of   platform in gimbal suspension, tuned rotor gyroscopes and pendulous accelerometers for a mode of preliminary bringing to horizon are reviewed. The mathematical description of the mode of preliminary bringing to horizon is derived and the appropriate control moments are determined.

  4. Sagnac interferometry with coherent vortex superposition states in exciton-polariton condensates

    Science.gov (United States)

    Moxley, Frederick Ira; Dowling, Jonathan P.; Dai, Weizhong; Byrnes, Tim

    2016-05-01

    We investigate prospects of using counter-rotating vortex superposition states in nonequilibrium exciton-polariton Bose-Einstein condensates for the purposes of Sagnac interferometry. We first investigate the stability of vortex-antivortex superposition states, and show that they survive at steady state in a variety of configurations. Counter-rotating vortex superpositions are of potential interest to gyroscope and seismometer applications for detecting rotations. Methods of improving the sensitivity are investigated by targeting high momentum states via metastable condensation, and the application of periodic lattices. The sensitivity of the polariton gyroscope is compared to its optical and atomic counterparts. Due to the large interferometer areas in optical systems and small de Broglie wavelengths for atomic BECs, the sensitivity per detected photon is found to be considerably less for the polariton gyroscope than with competing methods. However, polariton gyroscopes have an advantage over atomic BECs in a high signal-to-noise ratio, and have other practical advantages such as room-temperature operation, area independence, and robust design. We estimate that the final sensitivities including signal-to-noise aspects are competitive with existing methods.

  5. 39 (APPROXIMATE ANALYTICAL SOLUTION)

    African Journals Online (AJOL)

    Rotating machines like motors, turbines, compressors etc. are generally subjected to periodic forces and the system parameters remain more or less constant. ... parameters change and, consequently, the natural frequencies too, due to reasons of changing gyroscopic moments, centrifugal forces, bearing characteristics,.

  6. Chip Scale, Ultra Sensitive Opto Mechanical Acceleration and Force Sensors

    Science.gov (United States)

    2017-12-01

    statistics and, accordingly, the variance of the detected photon number will simply be, ndet, which is the number of photons hitting the detector. This...vibratory gyroscopes and the progress we made towards developing an optomechanical version. XI Introductory notes on rotation sensing The first question to

  7. Refinements and Tests of an Advanced Controller to Mitigate Fatigue Loads in the Controls Advanced Research Turbine

    NARCIS (Netherlands)

    Wright, A.D.; Fleming, P.; Van Wingerden, J.W.

    2011-01-01

    Wind turbines are complex, nonlinear, dynamic systems forced by aerodynamic, gravitational, centrifugal, and gyroscopic loads. The aerodynamics of wind turbines are nonlinear, unsteady, and complex. Turbine rotors are subjected to a complicated 3-D turbulent wind inflow field, with imbedded coherent

  8. Entrepreneurial Behaviour For Starting Professionals Of Generation Y : An Inductive Approach

    NARCIS (Netherlands)

    S. Nandram; Loredana Orhei; Joop Vinke

    2013-01-01

    As more and more research work is dedicated to the concept of entrepreneurial behaviour, more attention is also given to the teaching or training of such behaviour. In this paper we argue that a new integrative management approach, labeled as "gyroscopic management" (Vinke & Orhei, 2010, 2012), is

  9. Design of Attitude Control Actuators for a Simulated Spacecraft

    Science.gov (United States)

    2011-03-24

    however, there are many dual-use applications, such as regenerative braking technology and flywheel energy storage. The reaction wheel system on Simsat...as the reaction wheels change angular velocity. 2.3.5 Control Moment Gyroscopes. The second category of momentum ex- change devices is the control

  10. Possible physical manifestation of the Weyl non-Abelian gauge field

    International Nuclear Information System (INIS)

    Barbashov, B.M.; Pestov, A.B.

    1998-01-01

    On the basis of the Weyl equations of congruent transference, we consider a possible influence of the Weyl non-Abelian gauge field defining the transference on the precession of a gyroscope. Plane-wave solutions to the equations of the Abelian gauge field are derived

  11. 78 FR 31851 - Harmonization of Airworthiness Standards-Gust and Maneuver Load Requirements

    Science.gov (United States)

    2013-05-28

    ... airplanes equipped with wing-mounted engines; revise the engine torque loads criteria; add an engine failure...;'' 6. Add Sec. 25.362, ``Engine failure loads;'' 7. Amend Sec. 25.371, ``Gyroscopic loads;'' 8. Amend... of the design envelope analysis method. The elimination of the optional mission analysis method would...

  12. RoADS: A road pavement monitoring system for anomaly detection using smart phones

    NARCIS (Netherlands)

    Seraj, Fatjon; van der Zwaag, B.J.; Dilo, Arta; Luarasi, Tamara; Havinga, Paul J.M.; Atzmueller, Martin; Chin, Alvin; Janssen, Frederik; Schweizer, Immanuel; Trattner, Christoph

    2016-01-01

    Monitoring the road pavement is a challenging task. Authorities spend time and finances to monitor the state and quality of the road pavement. This paper investigate road surface monitoring with smartphones equipped with GPS and inertial sensors: accelerometer and gyroscope. In this study we

  13. RoADS: A road pavement monitoring system for anomaly detection using smart phones

    NARCIS (Netherlands)

    Seraj, Fatjon; van der Zwaag, B.J.; Dilo, Arta; Luarasi, Tamara; Havinga, Paul J.M.

    2014-01-01

    Monitoring the road pavement is a challenging task. Authorities spend time and finances to monitor the state and quality of the road pavement. This paper investigate road surface monitoring with smartphones equipped with GPS and inertial sensors: accelerometer and gyroscope. In this study we

  14. Defeating the U-boat. Inventing Antisubmarine Warfare (Newport Papers Number 36)

    Science.gov (United States)

    2010-08-01

    centered in France, had adherents among naval officers throughout the Continent, argued that “mosquito fleets” of tor- pedo boats and gunboats, not big...gyroscope. The weight of the warhead on the 1914 tor- pedo too was not much different from the 1904 model—about two hundred pounds; a contact fuse

  15. Utilizing Glove-Based Gestures and a Tactile Vest Display for Covert Communications and Robot Control

    Science.gov (United States)

    2014-06-01

    wearing instrumented glove for hand and arm signals. .......................................9 Figure 4. TDS Nomad handheld computer...of a standard tactical glove with accelerometers embedded within each finger, and an accelerometer, gyroscope, and digital compass embedded in the...signal communication were performed by two TDS Nomad GPS-enabled ruggedized handheld computers (one carried by the individual generating hand signals and

  16. Towards detection of bad habits by fusing smartphone and smartwatch sensors

    NARCIS (Netherlands)

    Shoaib, M.; Bosch, S.; Scholten, Johan; Havinga, Paul J.M.; Durmaz, O.

    2015-01-01

    Recently, there has been a growing interest in the research community about using wrist-worn devices, such as smartwatches for human activity recognition, since these devices are equipped with various sensors such as an accelerometer and a gyroscope. Similarly, smartphones are already being used for

  17. Development of a Low-Cost Attitude Sensor for Agricultural Vehicles

    Science.gov (United States)

    The objective of this research was to develop a low-cost attitude sensor for agricultural vehicles. The attitude sensor was composed of three vibratory gyroscopes and two inclinometers. A sensor fusion algorithm was developed to estimate tilt angles (roll and pitch) by least-squares method. In the a...

  18. Inertial Gait Phase Detection for control of a drop foot stimulator: Inertial sensing for gait phase detection

    NARCIS (Netherlands)

    Kotiadis, D.; Hermens, Hermanus J.; Veltink, Petrus H.

    An Inertial Gait Phase Detection system was developed to replace heel switches and footswitches currently being used for the triggering of drop foot stimulators. A series of four algorithms utilising accelerometers and gyroscopes individually and in combination were tested and initial results are

  19. A laser gyro with a four-mirror square resonator: formulas for simulating the dynamics of the synchronisation zone parameters of the frequencies of counterpropagating waves during the device operation in the self-heating regime

    International Nuclear Information System (INIS)

    Bondarenko, E A

    2014-01-01

    For a laser gyro with a four-mirror square resonator we have developed a mathematical model, which allows one to simulate the temporal behaviour of the synchronisation zone parameters of the frequencies of counterpropagating waves in a situation when the device operates in the self-heating regime and is switched-on at different initial temperatures. (laser gyroscopes)

  20. Inertial rotation measurement with atomic spins: From angular momentum conservation to quantum phase theory

    Science.gov (United States)

    Zhang, C.; Yuan, H.; Tang, Z.; Quan, W.; Fang, J. C.

    2016-12-01

    Rotation measurement in an inertial frame is an important technology for modern advanced navigation systems and fundamental physics research. Inertial rotation measurement with atomic spin has demonstrated potential in both high-precision applications and small-volume low-cost devices. After rapid development in the last few decades, atomic spin gyroscopes are considered a promising competitor to current conventional gyroscopes—from rate-grade to strategic-grade applications. Although it has been more than a century since the discovery of the relationship between atomic spin and mechanical rotation by Einstein [Naturwissenschaften, 3(19) (1915)], research on the coupling between spin and rotation is still a focus point. The semi-classical Larmor precession model is usually adopted to describe atomic spin gyroscope measurement principles. More recently, the geometric phase theory has provided a different view of the rotation measurement mechanism via atomic spin. The theory has been used to describe a gyroscope based on the nuclear spin ensembles in diamond. A comprehensive understanding of inertial rotation measurement principles based on atomic spin would be helpful for future applications. This work reviews different atomic spin gyroscopes and their rotation measurement principles with a historical overlook. In addition, the spin-rotation coupling mechanism in the context of the quantum phase theory is presented. The geometric phase is assumed to be the origin of the measurable rotation signal from atomic spins. In conclusion, with a complete understanding of inertial rotation measurements using atomic spin and advances in techniques, wide application of high-performance atomic spin gyroscopes is expected in the near future.

  1. Hovering and Transition Flight Tests of a 1/5-Scale Model of a Jet-Powered Vertical-Attitude VTOL Research Airplane

    Science.gov (United States)

    Smith, Charles C., Jr.

    1961-01-01

    An experimental investigation has been made to determine the dynamic stability and control characteristics of a 1/5-scale flying model of a jet-powered vertical-attitude VTOL research airplane in hovering and transition flight. The model was powered with either a hydrogen peroxide rocket motor or a compressed-air jet exhausting through an ejector tube to simulate the turbojet engine of the airplane. The gyroscopic effects of the engine were simulated by a flywheel driven by compressed-air jets. In hovering flight the model was controlled by jet-reaction controls which consisted of a swiveling nozzle on the main jet and a movable nozzle on each wing tip; and in forward flight the model was controlled by elevons and a rudder. If the gyroscopic effects of the jet engine were not represented, the model could be flown satisfactorily in hovering flight without any automatic stabilization devices. When the gyroscopic effects of the jet engine were represented, however, the model could not be controlled without the aid of artificial stabilizing devices because of the gyroscopic coupling of the yawing and pitching motions. The use of pitch and yaw dampers made these motions completely stable and the model could then be controlled very easily. In the transition flight tests, which were performed only with the automatic pitch and yaw dampers operating, it was found that the transition was very easy to perform either with or without the engine gyroscopic effects simulated, although the model had a tendency to fly in a rolled and sideslipped attitude at angles of attack between approximately 25 deg and 45 deg because of static directional instability in this range.

  2. Accuracy improvements of gyro-based measurement-while-drilling surveying instruments by a laser testing method

    Science.gov (United States)

    Li, Rong; Zhao, Jianhui; Li, Fan

    2009-07-01

    Gyroscope used as surveying sensor in the oil industry has been proposed as a good technique for measurement-whiledrilling (MWD) to provide real-time monitoring of the position and the orientation of the bottom hole assembly (BHA).However, drifts in the measurements provided by gyroscope might be prohibitive for the long-term utilization of the sensor. Some usual methods such as zero velocity update procedure (ZUPT) introduced to limit these drifts seem to be time-consuming and with limited effect. This study explored an in-drilling dynamic -alignment (IDA) method for MWD which utilizes gyroscope. During a directional drilling process, there are some minutes in the rotary drilling mode when the drill bit combined with drill pipe are rotated about the spin axis in a certain speed. This speed can be measured and used to determine and limit some drifts of the gyroscope which pay great effort to the deterioration in the long-term performance. A novel laser assembly is designed on the wellhead to count the rotating cycles of the drill pipe. With this provided angular velocity of the drill pipe, drifts of gyroscope measurements are translated into another form that can be easy tested and compensated. That allows better and faster alignment and limited drifts during the navigation process both of which can reduce long-term navigation errors, thus improving the overall accuracy in INS-based MWD system. This article concretely explores the novel device on the wellhead designed to test the rotation of the drill pipe. It is based on laser testing which is simple and not expensive by adding a laser emitter to the existing drilling equipment. Theoretical simulations and analytical approximations exploring the IDA idea have shown improvement in the accuracy of overall navigation and reduction in the time required to achieve convergence. Gyroscope accuracy along the axis is mainly improved. It is suggested to use the IDA idea in the rotary mode for alignment. Several other

  3. Research on Modeling of the Agile Satellite Using a Single Gimbal Magnetically Suspended CMG and the Disturbance Feedforward Compensation for Rotors

    Science.gov (United States)

    Cui, Peiling; Yan, Ning

    2012-01-01

    The magnetically suspended Control Moment Gyroscope (CMG) has the advantages of long-life, micro-vibration and being non-lubricating, and is the ideal actuator for agile maneuver satellite attitude control. However, the stability of the rotor in magnetic bearing and the precision of the output torque of a magnetically suspended CMG are affected by the rapid maneuvers of satellites. In this paper, a dynamic model of the agile satellite including a magnetically suspended single gimbal control moment gyroscope is built and the equivalent disturbance torque effected on the rotor is obtained. The feedforward compensation control method is used to depress the disturbance on the rotor. Simulation results are given to show that the rotor displacement is obviously reduced. PMID:23235442

  4. A Novel Vibration Mode Testing Method for Cylindrical Resonators Based on Microphones

    Directory of Open Access Journals (Sweden)

    Yongmeng Zhang

    2015-01-01

    Full Text Available Non-contact testing is an important method for the study of the vibrating characteristic of cylindrical resonators. For the vibratory cylinder gyroscope excited by piezo-electric electrodes, mode testing of the cylindrical resonator is difficult. In this paper, a novel vibration testing method for cylindrical resonators is proposed. This method uses a MEMS microphone, which has the characteristics of small size and accurate directivity, to measure the vibration of the cylindrical resonator. A testing system was established, then the system was used to measure the vibration mode of the resonator. The experimental results show that the orientation resolution of the node of the vibration mode is better than 0.1°. This method also has the advantages of low cost and easy operation. It can be used in vibration testing and provide accurate results, which is important for the study of the vibration mode and thermal stability of vibratory cylindrical gyroscopes.

  5. Research on Modeling of the Agile Satellite Using a Single Gimbal Magnetically Suspended CMG and the Disturbance Feedforward Compensation for Rotors

    Directory of Open Access Journals (Sweden)

    Ning Yan

    2012-12-01

    Full Text Available The magnetically suspended Control Moment Gyroscope (CMG has the advantages of long-life, micro-vibration and being non-lubricating, and is the ideal actuator for agile maneuver satellite attitude control. However, the stability of the rotor in magnetic bearing and the precision of the output torque of a magnetically suspended CMG are affected by the rapid maneuvers of satellites. In this paper, a dynamic model of the agile satellite including a magnetically suspended single gimbal control moment gyroscope is built and the equivalent disturbance torque effected on the rotor is obtained. The feedforward compensation control method is used to depress the disturbance on the rotor. Simulation results are given to show that the rotor displacement is obviously reduced.

  6. Gravity Probe B: final results of a space experiment to test general relativity.

    Science.gov (United States)

    Everitt, C W F; DeBra, D B; Parkinson, B W; Turneaure, J P; Conklin, J W; Heifetz, M I; Keiser, G M; Silbergleit, A S; Holmes, T; Kolodziejczak, J; Al-Meshari, M; Mester, J C; Muhlfelder, B; Solomonik, V G; Stahl, K; Worden, P W; Bencze, W; Buchman, S; Clarke, B; Al-Jadaan, A; Al-Jibreen, H; Li, J; Lipa, J A; Lockhart, J M; Al-Suwaidan, B; Taber, M; Wang, S

    2011-06-03

    Gravity Probe B, launched 20 April 2004, is a space experiment testing two fundamental predictions of Einstein's theory of general relativity (GR), the geodetic and frame-dragging effects, by means of cryogenic gyroscopes in Earth orbit. Data collection started 28 August 2004 and ended 14 August 2005. Analysis of the data from all four gyroscopes results in a geodetic drift rate of -6601.8±18.3  mas/yr and a frame-dragging drift rate of -37.2±7.2  mas/yr, to be compared with the GR predictions of -6606.1  mas/yr and -39.2  mas/yr, respectively ("mas" is milliarcsecond; 1  mas=4.848×10(-9)  rad).

  7. Sources of fatigue damage to passive yaw wind turbine blades

    Energy Technology Data Exchange (ETDEWEB)

    Laino, D.J. [Univ. of Utah, Salt Lake City, UT (United States)

    1997-12-31

    Using an integrated computer analysis approach developed at the University of Utah, fatigue damage sources to passive yaw wind turbine blades have been investigated. Models of a rigid hub and teetering hub machine reveal the parameters important to the fatigue design of each type. The teetering hub proved much less susceptible to fatigue damage from normal operation loads. As a result, extreme events were critical to the teetering hub fatigue life. The rigid hub blades experienced extremely large gyroscopic load cycles induced by rapid yaw rates during normal operation. These yaw rates stem from turbulence activity which is shown to be dependent upon atmospheric stability. Investigation revealed that increasing yaw damping is an effective way of significantly reducing these gyroscopic fatigue loads.

  8. The Development of Wireless Body Area Network for Motion Sensing Application

    Science.gov (United States)

    Puspitaningayu, P.; Widodo, A.; Yundra, E.; Ramadhany, F.; Arianto, L.; Habibie, D.

    2018-04-01

    The information era has driven the society into the digitally-controlled lifestyle. Wireless body area networks (WBAN) as the specific scope of wireless sensor networks (WSN) is consistently growing into bigger applications. Currently, people are able to monitor their medical parameters by simply using small electronics devices attached to their body and connected to the authorities. On top of that, this time, smart phones are typically equipped with sensors such as accelerometer, gyroscope, barometric pressure, heart rate monitor, etc. It means that the sensing yet the signal processing can be performed by a single device. Moreover, Android opens lot wider opportunities for new applications as the most popular open-sourced smart phone platform. This paper is intended to show the development of motion sensing application which focused on analysing data from accelerometer and gyroscope. Beside reads the sensors, this application also has the ability to convert the sensors’ numerical value into graphs.

  9. Point source atom interferometry with a cloud of finite size

    Energy Technology Data Exchange (ETDEWEB)

    Hoth, Gregory W., E-mail: gregory.hoth@nist.gov; Pelle, Bruno; Riedl, Stefan; Kitching, John; Donley, Elizabeth A. [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States)

    2016-08-15

    We demonstrate a two axis gyroscope by the use of light pulse atom interferometry with an expanding cloud of atoms in the regime where the cloud has expanded by 1.1–5 times its initial size during the interrogation. Rotations are measured by analyzing spatial fringe patterns in the atom population obtained by imaging the final cloud. The fringes arise from a correlation between an atom's initial velocity and its final position. This correlation is naturally created by the expansion of the cloud, but it also depends on the initial atomic distribution. We show that the frequency and contrast of these spatial fringes depend on the details of the initial distribution and develop an analytical model to explain this dependence. We also discuss several challenges that must be overcome to realize a high-performance gyroscope with this technique.

  10. Mission definition study for Stanford relativity satellite. Volume 2: Engineering flight test program

    Science.gov (United States)

    1971-01-01

    The need is examined for orbital flight tests of gyroscope, dewar, and other components, in order to reduce the technical and financial risk in performing the relativity experiment. A program is described that would generate engineering data to permit prediction of final performance. Two flight tests are recommended. The first flight would test a dewar smaller than that required for the final flight, but of size and form sufficient to allow extrapolation to the final design. The second flight would use the same dewar design to carry a set of three gyroscopes, which would be evaluated for spinup and drift characteristics for a period of a month or more. A proportional gas control system using boiloff helium gas from the dewar, and having the ability to prevent sloshing of liquid helium, would also be tested.

  11. A method for calibrating coil constants by using the free induction decay of noble gases

    Directory of Open Access Journals (Sweden)

    Linlin Chen

    2017-07-01

    Full Text Available We propose a precise method to calibrate the coil constants of spin-precession gyroscopes and optical atomic magnetometers. This method is based on measuring the initial amplitude of Free Induction Decay (FID of noble gases, from which the π/2 pulse duration can be calculated, since it is inversely proportional to the amplitude of the π/2 pulse. Therefore, the coil constants can be calibrated by measuring the π/2 pulse duration. Compared with the method based on the Larmor precession frequency of atoms, our method can avoid the effect of the pump and probe powers. We experimentally validated the method in a Nuclear Magnetic Resonance Gyroscope (NMRG, and the experimental results show that the coil constants are 436.63±0.04 nT/mA and 428.94±0.02 nT/mA in the x and y directions, respectively.

  12. Apparatus, system, and method for traffic monitoring

    KAUST Repository

    Claudel, Christian G.

    2016-08-25

    An apparatus, system, and method for traffic monitory can have a Lagrangian inertial measurement unit. The Lagrangian inertial measurement unit can have a processor, an accelerometer, a gyroscope, and/or a wireless transmitter. The processor can have an integrated direction cosine matrix. The accelerometer can be configured to measure linear accelerations of a vehicle and/or can communicate measured linear acceleration to the processor. The gyroscope can be configured to measure rotational accelerations of the vehicle and/or can communicate measured rotational acceleration to the processor. The processor can be configured to calculate estimated vehicle speed and/or estimated vehicle attitude. The wireless transmitter can be configured to wirelessly transmit estimated vehicle speed and/or estimated vehicle attitude. The apparatus, system, and method can be integrated with a wireless sensor network.

  13. Development of novel algorithm and real-time monitoring ambulatory system using Bluetooth module for fall detection in the elderly.

    Science.gov (United States)

    Hwang, J Y; Kang, J M; Jang, Y W; Kim, H

    2004-01-01

    Novel algorithm and real-time ambulatory monitoring system for fall detection in elderly people is described. Our system is comprised of accelerometer, tilt sensor and gyroscope. For real-time monitoring, we used Bluetooth. Accelerometer measures kinetic force, tilt sensor and gyroscope estimates body posture. Also, we suggested algorithm using signals which obtained from the system attached to the chest for fall detection. To evaluate our system and algorithm, we experimented on three people aged over 26 years. The experiment of four cases such as forward fall, backward fall, side fall and sit-stand was repeated ten times and the experiment in daily life activity was performed one time to each subject. These experiments showed that our system and algorithm could distinguish between falling and daily life activity. Moreover, the accuracy of fall detection is 96.7%. Our system is especially adapted for long-time and real-time ambulatory monitoring of elderly people in emergency situation.

  14. Dynamics and control of the GyroPTO wave energy point absorber under sea waves

    DEFF Research Database (Denmark)

    Zhang, Zili; Nielsen, Søren R.K.; Basu, Biswajit

    2017-01-01

    The Gyroscopic Power Take-Off (GyroPTO) wave energy point absorber has the operational principle somewhat similar to the so-called gyroscopic hand wrist exerciser. Inside the float of GyroPTO, there is a mechanical system made up of a spinning flywheel with its spin axis in rolling contact...... to a ring. At certain conditions, the ring starts to rotate at a frequency equal to the excitation angular frequency. In this synchronized state, the generator is running at almost constant speed and the generated power becomes constant. In this paper, theoretical modeling of the GyroPTO device is carried...... out based on analytical rigid body dynamics, and a 3-DOF nonlinear model is established. Simulation results show that synchronization of the device is maintained under harmonic sea wave, but is lost easily under non-harmonic sea waves.To overcome this problem, a magnetic coupling mechanism is added...

  15. Effect of low-frequency ambient magnetic fields on the control unit and RF head of a commercial SQUID magnetometer

    Science.gov (United States)

    Marcus, C. M.

    1984-01-01

    The control unit and RF head of the SHE model 330XRFSQUID system are shown to be sensitive to ambient ac magnetic fields below 1 HZ, which cause the appearance of false signals corresponding to a magnetometer signal of 0.000001 phi(0) per gauss of field applied. The control unit shows a sensitivity that is linear with frequency, suggesting that the signal is generated by Faraday induction. In contrast, the RF head response is independent of frequency and shows a strong second-harmonic coversion. This response may be due to the magnetic field sensitivity of the ferrite core inductor in the tuned amplifier of the RF head. These signals induced by ambient fields are a potential source of error in Stanford's Relativity Gyroscope experiment, which uses SQUID's on board a rolling satellite as part of the gyroscope readout system. The extent of the magnetic field sensitivity in these components necessitates the use of additional magnetic shielding aboard the satellite.

  16. Systems and Methods for Determining Inertial Navigation System Faults

    Science.gov (United States)

    Bharadwaj, Raj Mohan (Inventor); Bageshwar, Vibhor L. (Inventor); Kim, Kyusung (Inventor)

    2017-01-01

    An inertial navigation system (INS) includes a primary inertial navigation system (INS) unit configured to receive accelerometer measurements from an accelerometer and angular velocity measurements from a gyroscope. The primary INS unit is further configured to receive global navigation satellite system (GNSS) signals from a GNSS sensor and to determine a first set of kinematic state vectors based on the accelerometer measurements, the angular velocity measurements, and the GNSS signals. The INS further includes a secondary INS unit configured to receive the accelerometer measurements and the angular velocity measurements and to determine a second set of kinematic state vectors of the vehicle based on the accelerometer measurements and the angular velocity measurements. A health management system is configured to compare the first set of kinematic state vectors and the second set of kinematic state vectors to determine faults associated with the accelerometer or the gyroscope based on the comparison.

  17. Attitude Determination Method by Fusing Single Antenna GPS and Low Cost MEMS Sensors Using Intelligent Kalman Filter Algorithm

    Directory of Open Access Journals (Sweden)

    Lei Wang

    2017-01-01

    Full Text Available For meeting the demands of cost and size for micronavigation system, a combined attitude determination approach with sensor fusion algorithm and intelligent Kalman filter (IKF on low cost Micro-Electro-Mechanical System (MEMS gyroscope, accelerometer, and magnetometer and single antenna Global Positioning System (GPS is proposed. The effective calibration method is performed to compensate the effect of errors in low cost MEMS Inertial Measurement Unit (IMU. The different control strategies fusing the MEMS multisensors are designed. The yaw angle fusing gyroscope, accelerometer, and magnetometer algorithm is estimated accurately under GPS failure and unavailable sideslip situations. For resolving robust control and characters of the uncertain noise statistics influence, the high gain scale of IKF is adjusted by fuzzy controller in the transition process and steady state to achieve faster convergence and accurate estimation. The experiments comparing different MEMS sensors and fusion algorithms are implemented to verify the validity of the proposed approach.

  18. Effect of centrifugal force on natural frequency of lateral vibration of rotating shafts

    Science.gov (United States)

    Behzad, M.; Bastami, A. R.

    2004-07-01

    This paper investigates the effect of shaft rotation on its natural frequency. Apart from gyroscopic effect, the axial force originated from centrifugal force and the Poisson effect results in change of shaft natural frequency. D'Alembert principle for shaft in cylindrical co-ordinate system, along with the stress-strain relation, gives the non-homogenous linear differential equation, which can be used to calculate axial stress in the shaft. Numerical results of this study show that axial stress produced by shaft rotation has a major effect on the natural frequency of long high-speed shafts, while shaft diameter has no influence on the results. In addition, change in lateral natural frequency due to gyroscopic effect is compared with the results of this study.

  19. Investigation on dispersion in the active optical waveguide resonator

    Science.gov (United States)

    Qiu, Zihan; Gao, Yining; Xie, Wei

    2018-03-01

    Introducing active gain in the optical waveguide resonator not only compensates the loss, but also can change the dispersion relationship in the ring resonator. It is demonstrated that the group delay time is negative when the resonator is in the undercoupled condition, which also means the resonator exhibits the fast light effect. Theoretical analysis indicates that fast light effect due to anomalous dispersion, would be manipulated by the gain coefficient controlled by the input pump light power and that fast light would enhance scale factor of the optical resonant gyroscope. Resonance optical gyroscope (ROG)'s scale factor for measuring rotation rate is enhanced by anomalous dispersion with superluminal light propagation. The sensitivity of ROG could be enhanced by anomalous dispersion by coupled resonators even considering the effect of anomalous dispersion and propagation gain on broadened linewidth, and this could result in at least two orders of magnitude enhancement in sensitivity.

  20. The near-field acoustic levitation of high-mass rotors

    International Nuclear Information System (INIS)

    Hong, Z. Y.; Lü, P.; Geng, D. L.; Zhai, W.; Yan, N.; Wei, B.

    2014-01-01

    Here we demonstrate that spherical rotors with 40 mm diameter and 0-1 kg mass can be suspended more than tens of micrometers away from an ultrasonically vibrating concave surface by near-field acoustic radiation force. Their rotating speeds exceed 3000 rpm. An acoustic model has been developed to evaluate the near-field acoustic radiation force and the resonant frequencies of levitation system. This technique has potential application in developing acoustic gyroscope

  1. Satellite Hardware: Stow-and-Go for Space Travel

    OpenAIRE

    Pellegrino, Sergio

    2012-01-01

    Man-made satellites have to fit a lot into a compact package. Protected inside a rocket while blasted through the atmosphere, a satellite is launched into Earth orbit, or beyond, to continue its unmanned mission alone. It uses gyroscopes, altitude thrusters, and magnets to regulate sun exposure and stay pointed in the right direction. Once stable, the satellite depends on solar panels to recharge its internal batteries, mirrors, and lenses for data capture, and antennas for communication back...

  2. Gyro precession and Mach's principle

    International Nuclear Information System (INIS)

    Eby, P.

    1979-01-01

    The precession of a gyroscope is calculated in a nonrelativistic theory due to Barbour which satisfies Mach's principle. It is shown that the theory predicts both the geodetic and motional precession of general relativity to within factors of order 1. The significance of the gyro experiment is discussed from the point of view of metric theories of gravity and this is contrasted with its significance from the point of view of Mach's principle. (author)

  3. Augmented Mirror: Interactive Augmented Reality System Based on Kinect

    OpenAIRE

    Vera , Lucía; Gimeno , Jesús; Coma , Inmaculada; Fernández , Marcos

    2011-01-01

    Part 1: Long and Short Papers; International audience; In this paper we present a virtual character controlled by an actor in real time, who talks with an audience through an augmented mirror. The application, which integrates video images, the avatar and other virtual objects within an Augmented Reality system, has been implemented using a mixture of technologies: two kinect systems for motion capture, depth map and real images, a gyroscope to detect head movements, and control algorithms to...

  4. Quality of Information in Mobile Crowdsensing: Survey and Research Challenges

    OpenAIRE

    Restuccia, Francesco; Ghosh, Nirnay; Bhattacharjee, Shameek; Das, Sajal; Melodia, Tommaso

    2017-01-01

    Smartphones have become the most pervasive devices in people's lives, and are clearly transforming the way we live and perceive technology. Today's smartphones benefit from almost ubiquitous Internet connectivity and come equipped with a plethora of inexpensive yet powerful embedded sensors, such as accelerometer, gyroscope, microphone, and camera. This unique combination has enabled revolutionary applications based on the mobile crowdsensing paradigm, such as real-time road traffic monitorin...

  5. An Integrated System for Wildlife Sensing

    Science.gov (United States)

    2014-08-14

    velcro . Advantages of this method are that no permanent adhesive needs to be applied to the camera, and the entire case can be attached and detached...tripod, the Android device can be mounted as shown. Option 2: At the location shown in blue, a cellphone case can be attached using an adhesive and velcro ...Accelerometer 1 Accelerations along x, y, and z axes (includes effect of gravity) meters / second2 Gyroscope 4 Rates of rotation about x, y, and

  6. Handbook of force transducers

    CERN Document Server

    Stefanescu, Dan Mihai

    2011-01-01

    Part I introduces the basic ""Principles and Methods of Force Measurement"" acording to a classification into a dozen of force transducers types: resistive, inductive, capacitive, piezoelectric, electromagnetic, electrodynamic, magnetoelastic, galvanomagnetic (Hall-effect), vibrating wires, (micro)resonators, acoustic and gyroscopic. Two special chapters refer to force balance techniques and to combined methods in force measurement. Part II discusses the ""(Strain Gauge) Force Transducers Components"", evolving from the classical force transducer to the digital / intelligent one, with the inco

  7. A 10-gram Vision-based Flying Robot

    OpenAIRE

    Zufferey, Jean-Christophe; Klaptocz, Adam; Beyeler, Antoine; Nicoud, Jean-Daniel; Floreano, Dario

    2007-01-01

    We aim at developing ultralight autonomous microflyers capable of freely flying within houses or small built environments while avoiding collisions. Our latest prototype is a fixed-wing aircraft weighing a mere 10 g, flying around 1.5 m/s and carrying the necessary electronics for airspeed regulation and lateral collision avoidance. This microflyer is equipped with two tiny camera modules, two rate gyroscopes, an anemometer, a small microcontroller, and a Bluetooth rad...

  8. A 10-gram Microflyer for Vision-based Indoor Navigation

    OpenAIRE

    Zufferey, Jean-Christophe; Klaptocz, Adam; Beyeler, Antoine; Nicoud, Jean-Daniel; Floreano, Dario

    2006-01-01

    We aim at developing ultralight autonomous microflyers capable of navigating within houses or small built environments. Our latest prototype is a fixed-wing aircraft weighing a mere 10 g, flying around 1.5 m/s and carrying the necessary electronics for airspeed regulation and collision avoidance. This microflyer is equipped with two tiny camera modules, two rate gyroscopes, an anemometer, a small microcontroller, and a Bluetooth radio module. In-flight tests are carried out ...

  9. Using the global positioning satellite system to determine attitude rates using doppler effects

    Science.gov (United States)

    Campbell, Charles E. (Inventor)

    2003-01-01

    In the absence of a gyroscope, the attitude and attitude rate of a receiver can be determined using signals received by antennae on the receiver. Based on the signals received by the antennae, the Doppler difference between the signals is calculated. The Doppler difference may then be used to determine the attitude rate. With signals received from two signal sources by three antennae pairs, the three-dimensional attitude rate is determined.

  10. Visualizing Sound Directivity via Smartphone Sensors

    OpenAIRE

    Hawley, Scott H.; McClain Jr, Robert E.

    2017-01-01

    We present a fast, simple method for automated data acquisition and visualization of sound directivity, made convenient and accessible via a smartphone app, "Polar Pattern Plotter." The app synchronizes measurements of sound volume with the phone's angular orientation obtained from either compass, gyroscope or accelerometer sensors and produces a graph and exportable data file. It is generalizable to various sound sources and receivers via the use of an input-jack-adaptor to supplant the smar...

  11. Football Physics

    Science.gov (United States)

    Gay, Timothy

    2006-05-01

    This talk discusses a series of one-minute physics lectures given to the ˜ 8 x 10^4 fans that attend the University of Nebraska home football games. The lecture topics range from gyroscopic motion to ionizing collisions between linebackers and I-backs. The problem of simultaneous edification and amusement of the fan in the stands is considered. Several physics tips for the Vols will be proffered.

  12. Coupled vibrations in horizontal and vertical rotor-bearing systems

    OpenAIRE

    Luneno, Jean-Claude

    2011-01-01

    For dynamical systems having several degrees of freedom, motion in one direction can induce motion in the other. This means that there is a certain coupling between these two motions. Coupling can in some cases be a source of instability that causes self-excited vibrations in rotating machinery. In classical modeling of rotor systems, couplings other than those that are the result of gyroscopic effect are normally not considered. This is due to thecomplexity of the reasons for coupling which ...

  13. The near-field acoustic levitation of high-mass rotors

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Z. Y.; Lü, P.; Geng, D. L.; Zhai, W.; Yan, N.; Wei, B., E-mail: bbwei@nwpu.edu.cn [Department of Applied Physics, Northwestern Polytechnical University, Xi' an 710072 (China)

    2014-10-15

    Here we demonstrate that spherical rotors with 40 mm diameter and 0-1 kg mass can be suspended more than tens of micrometers away from an ultrasonically vibrating concave surface by near-field acoustic radiation force. Their rotating speeds exceed 3000 rpm. An acoustic model has been developed to evaluate the near-field acoustic radiation force and the resonant frequencies of levitation system. This technique has potential application in developing acoustic gyroscope.

  14. The near-field acoustic levitation of high-mass rotors.

    Science.gov (United States)

    Hong, Z Y; Lü, P; Geng, D L; Zhai, W; Yan, N; Wei, B

    2014-10-01

    Here we demonstrate that spherical rotors with 40 mm diameter and 0-1 kg mass can be suspended more than tens of micrometers away from an ultrasonically vibrating concave surface by near-field acoustic radiation force. Their rotating speeds exceed 3000 rpm. An acoustic model has been developed to evaluate the near-field acoustic radiation force and the resonant frequencies of levitation system. This technique has potential application in developing acoustic gyroscope.

  15. The Sagnac effect and its interpretation by Paul Langevin

    Science.gov (United States)

    Pascoli, Gianni

    2017-11-01

    The French physicist Georges Sagnac is nowdays frequently cited by the engineers who work on devices such as ring-laser gyroscopes. These systems operate on the principle of the Sagnac effect. It is less known that Sagnac was a strong opponent to the theory of special relativity proposed by Albert Einstein. He set up his experiment to prove the existence of the aether discarded by the Einsteinian relativity. An accurate explanation of the phenomenon was provided by Paul Langevin in 1921.

  16. The Future of Additive Manufacturing in the U.S. Military

    Science.gov (United States)

    2017-03-17

    innovators were applying the scientific advancements made in mathematics , physics, and chemistry to the development of machines that could help...printer housed on its 21 gyroscopically stabilized platform. Hours later, the part is complete and a quality control (QC) specialist inspects...Systems and Recent Efforts to Reform the Process. Moshe Schwartz Specialist in Defense Acquisition, 23 May 2014, 5. 64 Ibid., 7. 65 Department of

  17. Purwarupa Sistem Integrasi Quadcopter dan Mobile Robot

    OpenAIRE

    Dharmawan, Andi; Lusiarta Putera, Christian Antonia

    2012-01-01

    AbstrakQuadcopter, juga dikenal sebagai quadrotor, adalah helikopter dengan empat motor yang dilengkapi dengan  empat buah propeller pada masing-masing motornya yang digunakan untuk terbang dan bermanuver. Pada quadcopter terdapat 3 variabel sudut yang menjadi element utama dalam pengendaliannya yaitu roll, pitch, dan yaw yang diperoleh dari penggabungan sensor accelerometer, gyroscope dan magnetometer dengan metode Direction Cosine Matrix. Pada sistem integrasi mobile robot dan quadcopter, d...

  18. Synchronization of chaos in non-identical parametrically excited systems

    International Nuclear Information System (INIS)

    Idowu, B.A.; Vincent, U.E.; Njah, A.N.

    2009-01-01

    In this paper, we investigate the synchronization of chaotic systems consisting of non-identical parametrically excited oscillators. The active control technique is employed to design control functions based on Lyapunov stability theory and Routh-Hurwitz criteria so as to achieve global chaos synchronization between a parametrically excited gyroscope and each of the parametrically excited pendulum and Duffing oscillator. Numerical simulations are implemented to verify the results.

  19. A simple fall detection algorithm for Powered Two Wheelers

    OpenAIRE

    BOUBEZOUL, Abderrahmane; ESPIE, Stéphane; LARNAUDIE, Bruno; BOUAZIZ, Samir

    2013-01-01

    The aim of this study is to evaluate a low-complexity fall detection algorithm, that use both acceleration and angular velocity signals to trigger an alert-system or to inflate an airbag jacket. The proposed fall detection algorithm is a threshold-based algorithm, using data from 3-accelerometers and 3-gyroscopes sensors mounted on the motorcycle. During the first step, the commonly fall accident configurations were selected and analyzed in order to identify the main causation factors. On the...

  20. Development, Verification and Experimental Analysis of High-Fidelity Mathematical Models for Control Moment Gyros

    Science.gov (United States)

    2011-12-01

    34 Journal of Guidance Control Dynamics 16 (1993), 452. 22 Porter Davis, "Momentum System Concepts and Trades for the New Class of Smaller Lower Cost ...Smaller Lower Cost Satellites." Advances in the Astronautical Sciences 125, (2006): 13– 24. Dzielski, John, Edward Bergmann, Joseph Paradiso, Derek...Gyroscope Damping for Geocentric Attitude Control." Air Force Office of Scientific Research Report PIBMRI-1147-63, (May, 1963). Morine, L. A. and B. J

  1. Localization of Wheeled Mobile Robot Based on Extended Kalman Filtering

    Directory of Open Access Journals (Sweden)

    Li Guangxu

    2015-01-01

    Full Text Available A mobile robot localization method which combines relative positioning with absolute orientation is presented. The code salver and gyroscope are used for relative positioning, and the laser radar is used to detect absolute orientation. In this paper, we established environmental map, multi-sensor information fusion model, sensors and robot motion model. The Extended Kalman Filtering (EKF is adopted as multi-sensor data fusion technology to realize the precise localization of wheeled mobile robot.

  2. 2 DOF resolution adjustment laser position sensor

    CSIR Research Space (South Africa)

    Shaik, A

    2008-12-01

    Full Text Available means. [19, 20] Other - Displacement measuring instruments utilizing eddy currents, capacitive and inductive properties exist, but are not as widely spread as the technologies mentioned. Accelerometers and Gyroscopes are used to determine... resolution. The current accuracy of the IRB 340 Flex Picker, a rapid pick and place machine, is 0.1 mm. The lower limit on screen resolution for absolute 2D positioning would then be 400 phototransistors per square mm, a screen with twice the resolution...

  3. Theoretical frameworks for testing relativistic gravity: A review

    Science.gov (United States)

    Thorne, K. S.; Will, C. M.; Ni, W.

    1971-01-01

    Metric theories of gravity are presented, including the definition of metric theory, evidence for its existence, and response of matter to gravity with test body trajectories, gravitational red shift, and stressed matter responses. Parametrized post-Newtonian framework and interpretations are reviewed. Gamma, beta and gamma, and varied other parameters were measured. Deflection of electromagnetic waves, radar time delay, geodetic gyroscope precession, perihelion shifts, and periodic effects in orbits are among various studies carried out for metric theory experimentation.

  4. STUDY ABOUT THE STABILITY AND CONTROL OF A ROTOR AIRPLANE

    OpenAIRE

    Stafy, Victor; Neto, Aristeu Silveira

    2017-01-01

    On this paper is studied the stability and control of a Rotor Airplane, more specifically a MAV (Micro Air Vehicle) and how works the dynamics of flight of this unusual configuration of aircraft. It’s discussed the impact of the gyroscopic effect on stability (mainly lateral and directional stability) and was found the best feasible configuration of the stability surface, but the project of the stabilizers was limited to lifting surfaces that use airfoil sections, the possibility of a very un...

  5. Frequency-Domain Characterization of Optic Flow and Vision-Based Ocellar Sensing for Rotational Motion

    Science.gov (United States)

    2017-04-01

    public release; distribution is unlimited. 23 The servo motor can be operated in either position or velocity mode. Velocity mode does not offer control...corruption of the output signal. Alternative ground-truth options are the velocity readout from the servo motor controller and the gyroscope sensor...http://www.springer.com/us/book/9783211997482. 2. Mazokhin GA. Insect vision. New York (NY): Plenum Press ; 1969. 3. Horridge GA. Compound eye and

  6. Method and device for measuring the direction of a borehole

    International Nuclear Information System (INIS)

    Russell, M.K.; Russell, A.W.

    1979-01-01

    In a cylindrical casing there is arranged a gyroscopic rotor in two bearing brackets. The axis of the outer bearing bracket coincides with the axis of the casing. By means of a position indicator at the inner bracket, a torque-adjustment motor for bringing the inner bracket into a vertical position with respect to the outer one by precession, an angle indicator and a gravity sensor assembly there can be determined azimuth and elevation angles. (RW) [de

  7. Wearable sensor system for human localization and motion capture

    OpenAIRE

    Zihajehzadeh, Shaghayegh

    2017-01-01

    Recent advances in MEMS wearable inertial/magnetic sensors and mobile computing have fostered a dramatic growth of interest for ambulatory human motion capture (MoCap). Compared to traditional optical MoCap systems such as the optical systems, inertial (i.e. accelerometer and gyroscope) and magnetic sensors do not require external fixtures such as cameras. Hence, they do not have in-the-lab measurement limitations and thus are ideal for ambulatory applications. However, due to the manufacturi...

  8. Vibrations of axially moving strings with in-plane oscillating supports

    DEFF Research Database (Denmark)

    Fuglede, Niels; Thomsen, Jon Juel

    a uniform, heavy string moving at subcritical speed with prescribed endpoint motion, and ignoring longitudinal inertia, one obtains a continuous, nonlinear, gyroscopic, parametrically and externally excited system. By employing a single-mode approximation, using velocity dependent mode shapes, the system...... response is approximated using the method of multiple scales. Vibrations from support oscillations characteristic of roller chain drives are investigated. Conclusions about critical values for chain drive parameters such as pretension and meshing frequency are sought and identified....

  9. Complex modes and frequencies in damped structural vibrations

    DEFF Research Database (Denmark)

    Krenk, Steen

    2004-01-01

    It is demonstrated that the state space formulation of the equation of motion of damped structural elements like cables and beams leads to a symmetric eigenvalue problem if the stiffness and damping operators are self-adjoint, and that this is typically the case in the absence of gyroscopic forces....... The corresponding theory of complex modal analysis of continuous systems is developed and illustrated in relation to optimal damping and impulse response of cables and beams with discrete dampers....

  10. Predictive Attitude Maintenance For A Space Station

    Science.gov (United States)

    Hattis, Philip D.

    1989-01-01

    Paper provides mathematical basis for predictive management of angular momenta of control-moment gyroscopes (CMG's) to control attitude of orbiting space station. Numerical results presented for pitch control of proposed power-tower space station. Based on prior orbit history and mathematical model of density of atmosphere, predictions made of requirements on dumping and storage of angular momentum in relation to current loading state of CMG's and to acceptable attitude tolerances.

  11. Structural Characteristics of Rotate Vector Reducer Free Vibration

    Directory of Open Access Journals (Sweden)

    Chuan Chen

    2017-01-01

    Full Text Available For RV reducer widely used in robots, vibration significantly affects its performance. A lumped parameter model is developed to investigate free vibration characteristics without and with gyroscopic effects. The dynamic model considers key factors affecting vibration such as involute and cycloid gear mesh stiffness, crankshaft bending stiffness, and bearing stiffness. For both nongyroscopic and gyroscopic systems, free vibrations are examined and compared with each other. Results reveal the specific structure of vibration modes for both systems, which results from symmetry structure of RV reducer. According to vibration of the central components, vibration modes of two systems can be classified into three types, rotational, translational, and planetary component modes. Different from nongyroscopic system, the eigenvalues with gyroscopic effects are complex-valued and speed-dependent. The eigenvalue for a range of carrier speeds is obtained by numerical simulation. Divergence and flutter instability is observed at speeds adjacent to critical speeds. Furthermore, the work studies effects of key factors, which include crankshaft eccentricity and the number of pins, on eigenvalues. Finally, experiment is performed to verify the effectiveness of the dynamic model. The research of this paper is helpful for the analysis on free vibration and dynamic design of RV reducer.

  12. The Gravity Probe B Experiment

    Science.gov (United States)

    Kolodziejczak, Jeffrey

    2008-01-01

    This presentation briefly describes the Gravity Probe B (GP-B) Experiment which is designed to measure parts of Einstein's general theory of relativity by monitoring gyroscope orientation relative to a distant guide star. To measure the miniscule angles predicted by Einstein's theory, it was necessary to build near-perfect gyroscopes that were approximately 50 million times more precise than the best navigational gyroscopes. A telescope mounted along the central axis of the dewar and spacecraft provided the experiment's pointing reference to a guide star. The telescope's image divide precisely split the star's beam into x-axis and y-axis components whose brightness could be compared. GP-B's 650-gallon dewar, kept the science instrument inside the probe at a cryogenic temperature for 17.3 months and also provided the thruster propellant for precision attitude and translation control. Built around the dewar, the GP-B spacecraft was a total-integrated system, comprising both the space vehicle and payload, dedicated as a single entity to experimentally testing predictions of Einstein's theory.

  13. Perancangan Sistem Stabilisasi Kamera Tiga Sumbu dengan Metode Kontrol Fuzzy untuk Mobile Surveillance Robot

    Directory of Open Access Journals (Sweden)

    Fahrezi Alwi Muhammad

    2017-01-01

    Full Text Available Robot pengintaian (surveillance robot sering digunakan pada militer untuk melakukan tugas pengintaian sehingga tidak perlu membahayakan nyawa manusia karena dikendalikan dari jarak jauh. Robot pengintai memiliki kamera yang diletakkan di atas robot. Ketika melakukan pengamatan menggunakan kamera ini, seringkali pengamatan terganggu akibat guncangan-guncangan yang terjadi pada kamera. Guncangan ini disebabkan karena permukaan jalan yang dilalui oleh robot tidak rata. Sistem stabilisasi kamera adalah perangkat yang digunakan untuk menghilangkan guncangan dan menjaga posisi kamera agar kamera dapat mengambil gambar dengan baik pada suatu sudut pandang tertentu. Pada tugas akhir ini, dibuat sebuah sistem stabilisasi untuk robot pengintai dengan dua buah sensor gyroscope MPU-6050 untuk mengetahui kecepatan sudut guncangan dan kecepatan sudut kamera, mikrokontroler Arduino Mega sebagai pusat kontrol dan tiga buah motor DC brushless sebagai aktuator. Metode kontrol yang ditanamkan pada sistem terdiri dari tiga sistem Fuzzy untuk menangani sumbu pitch, roll, dan yaw. Pada tugas akhir ini diujikan dua metode. Metode pertama menggunakan satu sensor gyroscope sebagai nilai feedback, metode kedua menggunakan dua sensor gyroscope sebagai nilai feedback dan set point. Standar deviasi pada pengujian perekaman video tanpa kontrol untuk pixel x 40.57 dan pixel y 32.95. Standar deviasi dengan metode pertama untuk pixel x 24.73 adalah dan pixel y 21.73, Sedangkan standar deviasi metode kedua untuk pixel x 16.70 dan pixel y 22.44.

  14. A Wavelet-based method for processing signal of fog in strap-down inertial systems

    Energy Technology Data Exchange (ETDEWEB)

    Han, D.; Xiong, C.; Liu, H. [Huazhong University of Science & Technology, Wuhan (China)

    2009-07-01

    Fibre optical gyroscopes (FOGs) have been applied widely in many fields in contrast, with their counterparts such as mechanical gyroscopes and ring laser gyroscopes. The precision of FOG is affected significantly by bias drift, angle random walk temperature effects and noises. Especially, uncertain disturbances resulting from road irregularities often affect accuracy of strap-down inertial system (SINS). Hence, eliminating, uncertain disturbances from outputs of it FOG plays a crucial role to improve accuracy of SINS. This paper presents a wavelet-based method for denoising signals of FOGs in SINS used for exploring and rescuing robots in coal mines. Property of road irregularities in mines is taken into account as a key factor resulting in uncertain disturbances in this research. Both frequency band and amplitude of uncertain disturbances are introduced to choose filtering thresholds. Experimental results have demonstrated that the proposed method can efficiently eliminate uncertain disturbances due to road irregularities from outputs of FOGs and improve accuracy of surrogate data. It indicates that the proposed method has a significant potential in FOG-related applications.

  15. A wide-bandwidth and high-sensitivity robust microgyroscope

    International Nuclear Information System (INIS)

    Sahin, Korhan; Sahin, Emre; Akin, Tayfun; Alper, Said Emre

    2009-01-01

    This paper reports a microgyroscope design concept with the help of a 2 degrees of freedom (DoF) sense mode to achieve a wide bandwidth without sacrificing mechanical and electronic sensitivity and to obtain robust operation against variations under ambient conditions. The design concept is demonstrated with a tuning fork microgyroscope fabricated with an in-house silicon-on-glass micromachining process. When the fabricated gyroscope is operated with a relatively wide bandwidth of 1 kHz, measurements show a relatively high raw mechanical sensitivity of 131 µV (° s −1 ) −1 . The variation in the amplified mechanical sensitivity (scale factor) of the gyroscope is measured to be less than 0.38% for large ambient pressure variations such as from 40 to 500 mTorr. The bias instability and angle random walk of the gyroscope are measured to be 131° h −1 and 1.15° h −1/2 , respectively

  16. Fusing inertial sensor data in an extended Kalman filter for 3D camera tracking.

    Science.gov (United States)

    Erdem, Arif Tanju; Ercan, Ali Özer

    2015-02-01

    In a setup where camera measurements are used to estimate 3D egomotion in an extended Kalman filter (EKF) framework, it is well-known that inertial sensors (i.e., accelerometers and gyroscopes) are especially useful when the camera undergoes fast motion. Inertial sensor data can be fused at the EKF with the camera measurements in either the correction stage (as measurement inputs) or the prediction stage (as control inputs). In general, only one type of inertial sensor is employed in the EKF in the literature, or when both are employed they are both fused in the same stage. In this paper, we provide an extensive performance comparison of every possible combination of fusing accelerometer and gyroscope data as control or measurement inputs using the same data set collected at different motion speeds. In particular, we compare the performances of different approaches based on 3D pose errors, in addition to camera reprojection errors commonly found in the literature, which provides further insight into the strengths and weaknesses of different approaches. We show using both simulated and real data that it is always better to fuse both sensors in the measurement stage and that in particular, accelerometer helps more with the 3D position tracking accuracy, whereas gyroscope helps more with the 3D orientation tracking accuracy. We also propose a simulated data generation method, which is beneficial for the design and validation of tracking algorithms involving both camera and inertial measurement unit measurements in general.

  17. Recent Developments Of Optical Fiber Sensors For Automotive Use

    Science.gov (United States)

    Sasayama, Takao; Oho, Shigeru; Kuroiwa, Hiroshi; Suzuki, Seikoo

    1987-12-01

    Optical fiber sensing technologies are expected to apply for many future electronic control systems in automobiles, because of their original outstanding features, such as high noise immunity, high heat resistance, and flexible light propagation paths which can be applicable to measure the movements and directions of the mobiles. In this paper, two typical applications of fiber sensing technologies in automobiles have been described in detail. The combustion flame detector is one of the typical applications of a fiber spectroscopic technology which utilizes the feature of high noise and heat resistibility and remote sensibility. Measurements of engine combustion conditions, such as the detonation, the combustion initiation, and the air-fuel ratio, have been demonstrated in an experimental fiber sensing method. Fiber interferometers, such as a fiber gyroscope, have a lot of possibilities in future mobile applications because they are expandable to many kinds of measurements for movements and physical variables. An optical fiber gyroscope utilizing the single polarized optical fiber and optical devices has been developed. Quite an accurate measurement of vehicle position was displayed on a prototype navigation system which installed the fiber gyroscope as a rotational speed sensor.

  18. Visual attitude propagation for small satellites

    Science.gov (United States)

    Rawashdeh, Samir A.

    As electronics become smaller and more capable, it has become possible to conduct meaningful and sophisticated satellite missions in a small form factor. However, the capability of small satellites and the range of possible applications are limited by the capabilities of several technologies, including attitude determination and control systems. This dissertation evaluates the use of image-based visual attitude propagation as a compliment or alternative to other attitude determination technologies that are suitable for miniature satellites. The concept lies in using miniature cameras to track image features across frames and extracting the underlying rotation. The problem of visual attitude propagation as a small satellite attitude determination system is addressed from several aspects: related work, algorithm design, hardware and performance evaluation, possible applications, and on-orbit experimentation. These areas of consideration reflect the organization of this dissertation. A "stellar gyroscope" is developed, which is a visual star-based attitude propagator that uses relative motion of stars in an imager's field of view to infer the attitude changes. The device generates spacecraft relative attitude estimates in three degrees of freedom. Algorithms to perform the star detection, correspondence, and attitude propagation are presented. The Random Sample Consensus (RANSAC) approach is applied to the correspondence problem to successfully pair stars across frames while mitigating falsepositive and false-negative star detections. This approach provides tolerance to the noise levels expected in using miniature optics and no baffling, and the noise caused by radiation dose on orbit. The hardware design and algorithms are validated using test images of the night sky. The application of the stellar gyroscope as part of a CubeSat attitude determination and control system is described. The stellar gyroscope is used to augment a MEMS gyroscope attitude propagation

  19. Thermal Actuation Based 3-DoF Non-Resonant Microgyroscope Using MetalMUMPs

    Directory of Open Access Journals (Sweden)

    Muhammad Masood ul Hassan

    2009-04-01

    Full Text Available High force, large displacement and low voltage consumption are a primary concern for microgyroscopes. The chevron-shaped thermal actuators are unique in terms of high force generation combined with the large displacements at a low operating voltage in comparison with traditional electrostatic actuators. A Nickel based 3-DoF micromachined gyroscope comprising 2-DoF drive mode and 1-DoF sense mode oscillator utilizing the chevron-shaped thermal actuators is presented here. Analytical derivations and finite element simulations are carried out to predict the performance of the proposed device using the thermo-physical properties of electroplated nickel. The device sensitivity is improved by utilizing the dynamical amplification of the oscillation in 2-DoF drive mode using an active-passive mass configuration. A comprehensive theoretical description, dynamics and mechanical design considerations of the proposed gyroscopes model are discussed in detail. Parametric optimization of gyroscope, its prototype modeling and fabrication using MetalMUMPs has also been investigated. Dynamic transient simulation results predicted that the sense mass of the proposed device achieved a drive displacement of 4.1µm when a sinusoidal voltage of 0.5V is applied at 1.77 kHz exhibiting a mechanical sensitivity of 1.7μm /o/s in vacuum. The wide bandwidth frequency response of the 2-DoF drive mode oscillator consists of two resonant peaks and a flat region of 2.11 kHz between the peaks defining the operational frequency region. The sense mode resonant frequency can lie anywhere within this region and therefore the amplitude of the response is insensitive to structural parameter variations, enhancing device robustness against such variations. The proposed device has a size of 2.2 x 2.6 mm2, almost one third in comparison with existing M-DoF vibratory gyroscope with an estimated power consumption of 0.26 Watts. These predicted results illustrate that the chevron

  20. Recognizing the Operating Hand and the Hand-Changing Process for User Interface Adjustment on Smartphones.

    Science.gov (United States)

    Guo, Hansong; Huang, He; Huang, Liusheng; Sun, Yu-E

    2016-08-20

    As the size of smartphone touchscreens has become larger and larger in recent years, operability with a single hand is getting worse, especially for female users. We envision that user experience can be significantly improved if smartphones are able to recognize the current operating hand, detect the hand-changing process and then adjust the user interfaces subsequently. In this paper, we proposed, implemented and evaluated two novel systems. The first one leverages the user-generated touchscreen traces to recognize the current operating hand, and the second one utilizes the accelerometer and gyroscope data of all kinds of activities in the user's daily life to detect the hand-changing process. These two systems are based on two supervised classifiers constructed from a series of refined touchscreen trace, accelerometer and gyroscope features. As opposed to existing solutions that all require users to select the current operating hand or confirm the hand-changing process manually, our systems follow much more convenient and practical methods and allow users to change the operating hand frequently without any harm to the user experience. We conduct extensive experiments on Samsung Galaxy S4 smartphones, and the evaluation results demonstrate that our proposed systems can recognize the current operating hand and detect the hand-changing process with 94.1% and 93.9% precision and 94.1% and 93.7% True Positive Rates (TPR) respectively, when deciding with a single touchscreen trace or accelerometer-gyroscope data segment, and the False Positive Rates (FPR) are as low as 2.6% and 0.7% accordingly. These two systems can either work completely independently and achieve pretty high accuracies or work jointly to further improve the recognition accuracy.

  1. Gravitational Physics Research

    Science.gov (United States)

    Wu, S. T.

    2000-01-01

    Gravitational physics research at ISPAE is connected with NASA's Relativity Mission (Gravity Probe B (GP-B)) which will perform a test of Einstein's General Relativity Theory. GP-B will measure the geodetic and motional effect predicted by General Relativity Theory with extremely stable and sensitive gyroscopes in an earth orbiting satellite. Both effects cause a very small precession of the gyroscope spin axis. The goal of the GP-B experiment is the measurement of the gyroscope precession with very high precision. GP-B is being developed by a team at Stanford University and is scheduled for launch in the year 2001. The related UAH research is a collaboration with Stanford University and MSFC. This research is focussed primarily on the error analysis and data reduction methods of the experiment but includes other topics concerned with experiment systems and their performance affecting the science measurements. The hydrogen maser is the most accurate and stable clock available. It will be used in future gravitational physics missions to measure relativistic effects such as the second order Doppler effect. The HMC experiment, currently under development at the Smithsonian Astrophysical Observatory (SAO), will test the performance and capability of the hydrogen maser clock for gravitational physics measurements. UAH in collaboration with the SAO science team will study methods to evaluate the behavior and performance of the HMC. The GP-B data analysis developed by the Stanford group involves complicated mathematical operations. This situation led to the idea to investigate alternate and possibly simpler mathematical procedures to extract the GP-B measurements form the data stream. Comparison of different methods would increase the confidence in the selected scheme.

  2. Recognizing the Operating Hand and the Hand-Changing Process for User Interface Adjustment on Smartphones †

    Science.gov (United States)

    Guo, Hansong; Huang, He; Huang, Liusheng; Sun, Yu-E

    2016-01-01

    As the size of smartphone touchscreens has become larger and larger in recent years, operability with a single hand is getting worse, especially for female users. We envision that user experience can be significantly improved if smartphones are able to recognize the current operating hand, detect the hand-changing process and then adjust the user interfaces subsequently. In this paper, we proposed, implemented and evaluated two novel systems. The first one leverages the user-generated touchscreen traces to recognize the current operating hand, and the second one utilizes the accelerometer and gyroscope data of all kinds of activities in the user’s daily life to detect the hand-changing process. These two systems are based on two supervised classifiers constructed from a series of refined touchscreen trace, accelerometer and gyroscope features. As opposed to existing solutions that all require users to select the current operating hand or confirm the hand-changing process manually, our systems follow much more convenient and practical methods and allow users to change the operating hand frequently without any harm to the user experience. We conduct extensive experiments on Samsung Galaxy S4 smartphones, and the evaluation results demonstrate that our proposed systems can recognize the current operating hand and detect the hand-changing process with 94.1% and 93.9% precision and 94.1% and 93.7% True Positive Rates (TPR) respectively, when deciding with a single touchscreen trace or accelerometer-gyroscope data segment, and the False Positive Rates (FPR) are as low as 2.6% and 0.7% accordingly. These two systems can either work completely independently and achieve pretty high accuracies or work jointly to further improve the recognition accuracy. PMID:27556461

  3. Classification of team sport activities using a single wearable tracking device.

    Science.gov (United States)

    Wundersitz, Daniel W T; Josman, Casey; Gupta, Ritu; Netto, Kevin J; Gastin, Paul B; Robertson, Sam

    2015-11-26

    Wearable tracking devices incorporating accelerometers and gyroscopes are increasingly being used for activity analysis in sports. However, minimal research exists relating to their ability to classify common activities. The purpose of this study was to determine whether data obtained from a single wearable tracking device can be used to classify team sport-related activities. Seventy-six non-elite sporting participants were tested during a simulated team sport circuit (involving stationary, walking, jogging, running, changing direction, counter-movement jumping, jumping for distance and tackling activities) in a laboratory setting. A MinimaxX S4 wearable tracking device was worn below the neck, in-line and dorsal to the first to fifth thoracic vertebrae of the spine, with tri-axial accelerometer and gyroscope data collected at 100Hz. Multiple time domain, frequency domain and custom features were extracted from each sensor using 0.5, 1.0, and 1.5s movement capture durations. Features were further screened using a combination of ANOVA and Lasso methods. Relevant features were used to classify the eight activities performed using the Random Forest (RF), Support Vector Machine (SVM) and Logistic Model Tree (LMT) algorithms. The LMT (79-92% classification accuracy) outperformed RF (32-43%) and SVM algorithms (27-40%), obtaining strongest performance using the full model (accelerometer and gyroscope inputs). Processing time can be reduced through feature selection methods (range 1.5-30.2%), however a trade-off exists between classification accuracy and processing time. Movement capture duration also had little impact on classification accuracy or processing time. In sporting scenarios where wearable tracking devices are employed, it is both possible and feasible to accurately classify team sport-related activities. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. IMPACT STUDY OF ANISOTROPIC OPTICAL FIBERS WINDING WITH DIFFERENT TENSION VALUE ON THE H-PARAMETER INVARIANCE DEGREE

    Directory of Open Access Journals (Sweden)

    A. B. Mukhtubayev

    2015-09-01

    Full Text Available Subject of Research. We have investigated the effect of anisotropic optical fibers winding with an elliptical sheath subjecting to stress on the H-parameter invariance degree. This type of optical fiber is used in the manufacture of fiber loop in fiber-optic gyroscopes. Method of Research. The method of research is based on the application of Michelson polarization scanning interferometer as a measuring device. Superluminescent diode with a central wavelength of 1575 nm and a half-width of the spectrum equal to 45 nm is used as a radiation source. The studies were carried out with anisotropic optical fiber with 50 m long elliptical sheath subjecting to stress. The fiber was wound with one layer turn to turn on the coil with a diameter of 18 cm, which is used in the design of fiber-optic gyroscope. The tension force of the optical fiber was controlled during winding on a special machine. Main Results. It was found that at the increase of tension force from 0.05 N to 0.8 H the value of H-parameter increases from 7×10-6 1/m up to 178×10-6 1/m, respectively; i.e. the coupling coefficient of orthogonal modes in the test fiber is being increased. Thus, it is necessary to consider the longitudinal tension force of fiber in the design and manufacture of the fiber-optic sensors of high accuracy class: the less the fiber winding power, the higher invariance degree of distributed H-parameter. The longitudinal tension force of anisotropic optical fiber with elliptical sheath subjecting to stress equal to 0.2 N is recommended in the process of designing fiber-optic gyroscopes. Practical Relevance. The proposed method of Michelson scanning interferometer is usable in the production process for quality determination of the optical fiber winding: no local defects, value controlling of fiber H-parameter.

  5. Recognizing the Operating Hand and the Hand-Changing Process for User Interface Adjustment on Smartphones

    Directory of Open Access Journals (Sweden)

    Hansong Guo

    2016-08-01

    Full Text Available As the size of smartphone touchscreens has become larger and larger in recent years, operability with a single hand is getting worse, especially for female users. We envision that user experience can be significantly improved if smartphones are able to recognize the current operating hand, detect the hand-changing process and then adjust the user interfaces subsequently. In this paper, we proposed, implemented and evaluated two novel systems. The first one leverages the user-generated touchscreen traces to recognize the current operating hand, and the second one utilizes the accelerometer and gyroscope data of all kinds of activities in the user’s daily life to detect the hand-changing process. These two systems are based on two supervised classifiers constructed from a series of refined touchscreen trace, accelerometer and gyroscope features. As opposed to existing solutions that all require users to select the current operating hand or confirm the hand-changing process manually, our systems follow much more convenient and practical methods and allow users to change the operating hand frequently without any harm to the user experience. We conduct extensive experiments on Samsung Galaxy S4 smartphones, and the evaluation results demonstrate that our proposed systems can recognize the current operating hand and detect the hand-changing process with 94.1% and 93.9% precision and 94.1% and 93.7% True Positive Rates (TPR respectively, when deciding with a single touchscreen trace or accelerometer-gyroscope data segment, and the False Positive Rates (FPR are as low as 2.6% and 0.7% accordingly. These two systems can either work completely independently and achieve pretty high accuracies or work jointly to further improve the recognition accuracy.

  6. An alternative sensor fusion method for object orientation using low-cost MEMS inertial sensors

    Science.gov (United States)

    Bouffard, Joshua L.

    This thesis develops an alternative sensor fusion approach for object orientation using low-cost MEMS inertial sensors. The alternative approach focuses on the unique challenges of small UAVs. Such challenges include the vibrational induced noise onto the accelerometer and bias offset errors of the rate gyroscope. To overcome these challenges, a sensor fusion algorithm combines the measured data from the accelerometer and rate gyroscope to achieve a single output free from vibrational noise and bias offset errors. One of the most prevalent sensor fusion algorithms used for orientation estimation is the Extended Kalman filter (EKF). The EKF filter performs the fusion process by first creating the process model using the nonlinear equations of motion and then establishing a measurement model. With the process and measurement models established, the filter operates by propagating the mean and covariance of the states through time. The success of EKF relies on the ability to establish a representative process and measurement model of the system. In most applications, the EKF measurement model utilizes the accelerometer and GPS-derived accelerations to determine an estimate of the orientation. However, if the GPS-derived accelerations are not available then the measurement model becomes less reliable when subjected to harsh vibrational environments. This situation led to the alternative approach, which focuses on the correlation between the rate gyroscope and accelerometer-derived angle. The correlation between the two sensors then determines how much the algorithm will use one sensor over the other. The result is a measurement that does not suffer from the vibrational noise or from bias offset errors.

  7. Optical polarimetry for noninvasive glucose sensing enabled by Sagnac interferometry.

    Science.gov (United States)

    Winkler, Amy M; Bonnema, Garret T; Barton, Jennifer K

    2011-06-10

    Optical polarimetry is used in pharmaceutical drug testing and quality control for saccharide-containing products (juice, honey). More recently, it has been proposed as a method for noninvasive glucose sensing for diabetic patients. Sagnac interferometry is commonly used in optical gyroscopes, measuring minute Doppler shifts resulting from mechanical rotation. In this work, we demonstrate that Sagnac interferometers are also sensitive to optical rotation, or the rotation of linearly polarized light, and are therefore useful in optical polarimetry. Results from simulation and experiment show that Sagnac interferometers are advantageous in optical polarimetry as they are insensitive to net linear birefringence and alignment of polarization components.

  8. Real-time estimation of helicopter rotor blade kinematics through measurement of rotation induced acceleration

    Science.gov (United States)

    Allred, C. Jeff; Churchill, David; Buckner, Gregory D.

    2017-07-01

    This paper presents a novel approach to monitoring rotor blade flap, lead-lag and pitch using an embedded gyroscope and symmetrically mounted MEMS accelerometers. The central hypothesis is that differential accelerometer measurements are proportional only to blade motion; fuselage acceleration and blade bending are inherently compensated for. The inverse kinematic relationships (from blade position to acceleration and angular rate) are derived and simulated to validate this hypothesis. An algorithm to solve the forward kinematic relationships (from sensor measurement to blade position) is developed using these simulation results. This algorithm is experimentally validated using a prototype device. The experimental results justify continued development of this kinematic estimation approach.

  9. The Parrot UAV Controlled by PID Controllers

    OpenAIRE

    Koszewnik Andrzej

    2014-01-01

    The paper presents the process of modeling and designing control laws for four-rotor type of the Parrot UAV. The state space model is obtained by using several phenomena like gyroscopic effects for rigid bodies, propellers and rotors. The obtained model has been used to design PID control laws for roll, pitch, yaw angle and altitude, respectively. The numerical simulations of the closed loop model are shown that system in satisfy way stabilize flight of the quadro-rotor in all considered dire...

  10. The Parrot UAV Controlled by PID Controllers

    Directory of Open Access Journals (Sweden)

    Koszewnik Andrzej

    2014-08-01

    Full Text Available The paper presents the process of modeling and designing control laws for four-rotor type of the Parrot UAV. The state space model is obtained by using several phenomena like gyroscopic effects for rigid bodies, propellers and rotors. The obtained model has been used to design PID control laws for roll, pitch, yaw angle and altitude, respectively. The numerical simulations of the closed loop model are shown that system in satisfy way stabilize flight of the quadro-rotor in all considered directions.

  11. Research on the attitude of small UAV based on MEMS devices

    Science.gov (United States)

    Shi, Xiaojie; Lu, Libin; Jin, Guodong; Tan, Lining

    2017-05-01

    This paper mainly introduces the research principle and implementation method of the small UAV navigation attitude system based on MEMS devices. The Gauss - Newton method based on least squares is used to calibrate the MEMS accelerometer and gyroscope for calibration. Improve the accuracy of the attitude by using the modified complementary filtering to correct the attitude angle error. The experimental data show that the design of the attitude and attitude system in this paper to meet the requirements of small UAV attitude accuracy to achieve a small, low cost.

  12. Harmonic oscillations, chaos and synchronization in systems consisting of Van der Pol oscillator coupled to a linear oscillator

    International Nuclear Information System (INIS)

    Woafo, P.

    1999-12-01

    This paper deals with the dynamics of a model describing systems consisting of the classical Van der Pol oscillator coupled gyroscopically to a linear oscillator. Both the forced and autonomous cases are considered. Harmonic response is investigated along with its stability boundaries. Condition for quenching phenomena in the autonomous case is derived. Neimark bifurcation is observed and it is found that our model shows period doubling and period-m sudden transitions to chaos. Synchronization of two and more systems in their chaotic regime is presented. (author)

  13. Symposium Gyro Technology 1984; Proceedings of the Symposium, Universitaet Stuttgart, West Germany, September 11, 12, 1984

    Science.gov (United States)

    Sorg, H.

    Among the topics discussed are: drift and scale factor tests on the SEL fiber gyro; integrated optical rate sensor development; and the beam geometry of a ring laser gyro in relation to its performance. Consideration is also given to: a fast filtering technique for measuring random walk in a laser gyro; vibratory gyroscopic sensors; a redundant strapdown reference for advanced aircraft flight control systems; and a low-cost piezoelectric rate/acceleration sensor. Additional topics include: an inertial guidance system for a Low-Earth-Orbit (LEO) vehicle; and signal disturbance effects in a strapdown northfinder.

  14. Mobile Phones Coupled with Remote Sensors for Surveillance

    Science.gov (United States)

    2012-03-01

    Buildroot, that supports C/C++ and Java programming languages. The use of the configuration GUI is supported by an internet browser. 7 For remote...C++, Flash 9, Flex, Java , LabVIEW, Python, Max/MSP, and Cocoa [4]. The following are the specifications of the 1072 PhidgetSBC2 from the product...Gyroscope can measure angular rotation up to ±400° per second.  Magnetometer, or compass, measures the magnetic field up to ±4 Gauss. It reports

  15. Prospects for MEMS in the Automotive Industry

    Directory of Open Access Journals (Sweden)

    Richard DIXON

    2007-12-01

    Full Text Available An automotive sector as a growth market for MEMS sensors is analyzed in the article. The automotive sector accounted for $1.6 billion, making this the second biggest opportunity after IT peripherals and inkjet print heads. By 2011 the market will top $2.2 billion, a CAGR of around 7%. The main applications in revenues terms are, in order, pressure sensors, gyroscopes, accelerometers and flow sensors and this will remain so for the foreseeable future. Automotive companies are forced to innovate as a result of competition and price pressures.

  16. Semantics in mobile sensing

    CERN Document Server

    Yan, Zhixian

    2014-01-01

    The dramatic progress of smartphone technologies has ushered in a new era of mobile sensing, where traditional wearable on-body sensors are being rapidly superseded by various embedded sensors in our smartphones. For example, a typical smartphone today, has at the very least a GPS, WiFi, Bluetooth, triaxial accelerometer, and gyroscope. Alongside, new accessories are emerging such as proximity, magnetometer, barometer, temperature, and pressure sensors. Even the default microphone can act as an acoustic sensor to track noise exposure for example. These sensors act as a ""lens"" to understand t

  17. Bifurcation of the roots of the characteristic polynomial and the destabilization paradox in friction induced oscillations

    Directory of Open Access Journals (Sweden)

    Kirillov O.N.

    2007-01-01

    Full Text Available Paradoxical effect of small dissipative and gyroscopic forces on the stability of a linear non-conservative system, which manifests itself through the unpredictable at first sight behavior of the critical non-conservative load, is studied. By means of the analysis of bifurcation of multiple roots of the characteristic polynomial of the non-conservative system, the analytical description of this phenomenon is obtained. As mechanical examples two systems possessing friction induced oscillations are considered: a mass sliding over a conveyor belt and a model of a disc brake describing the onset of squeal during the braking of a vehicle.

  18. STS-103 Crew Interviews: Scott Kelly

    Science.gov (United States)

    1999-01-01

    Live footage of a preflight interview with Pilot Scott J. Kelly is seen. The interview addresses many different questions including why Kelly became an astronaut, the events that led to his interest, any role models that he had, and his inspiration. Other interesting information that this one-on-one interview discusses is an explanation of the why this required mission to service the Hubble Space Telescope must take place at such an early date, replacement of the gyroscopes, transistors, and computers. Also discussed are the Chandra X Ray Astrophysics Facility, and a brief touch on Kelly's responsibility during any of the given four space walks scheduled for this mission.

  19. Smart Rocking Armour Units

    OpenAIRE

    Hofland, B.; Arefin, Syed Shamsil; van der Lem, Cock; van gent, Marcel

    2018-01-01

    This paper describes a method to measure the rocking motion of lab-scale armour units. Sensors as found in mobile phones are used. These sensors, data-storage and battery are all embedded in the model units, such that they can be applied without wires attached to them. The technique is applied to double-layer units in order to compare the results to the existing knowledge for this type of armour layers. In contrast to previous research, the gyroscope reading is used to determine the (rocking)...

  20. Multi-Parameter Wireless Monitoring and Telecommand of a Rocket Payload: Design and Implementation

    Science.gov (United States)

    Pamungkas, Arga C.; Putra, Alma A.; Puspitaningayu, Pradini; Fransisca, Yulia; Widodo, Arif

    2018-04-01

    A rocket system generally consists of two parts, the rocket motor and the payload. The payload system is built of several sensors such as accelerometer, gyroscope, magnetometer, and also a surveillance camera. These sensors are used to monitor the rocket in a three-dimensional axis which determine its attitude. Additionally, the payload must be able to perform image capturing in a certain distance using telecommand. This article is intended to describe the design and also the implementation of a rocket payload which has attitude monitoring and telecommand ability from the ground control station using a long-range wireless module Digi XBee Pro 900 HP.

  1. Essential technologies for developing human and robot collaborative system

    International Nuclear Information System (INIS)

    Ishikawa, Nobuyuki; Suzuki, Katsuo

    1997-10-01

    In this study, we aim to develop a concept of new robot system, i.e., 'human and robot collaborative system', for the patrol of nuclear power plants. This paper deals with the two essential technologies developed for the system. One is the autonomous navigation program with human intervention function which is indispensable for human and robot collaboration. The other is the position estimation method by using gyroscope and TV image to make the estimation accuracy much higher for safe navigation. Feasibility of the position estimation method is evaluated by experiment and numerical simulation. (author)

  2. Learning Physics Down a Slide: A Set of Experiments to Measure Reality Through Smartphone Sensors

    Directory of Open Access Journals (Sweden)

    Lander Martínez

    2014-06-01

    Full Text Available During the last decade, the use of smartphones among teenagers in their daily life has grown significantly. Despite the efforts to use tablets in learning processes, these teenagers are often prompted to switch off their personal devices before entering a classroom. Moreover, most mobile learning applications do not take advantage of the device sensors (e.g., touchscreen, accelerometer, or gyroscope. In order to overcome this situation, we have developed Serious Physics, a free mobile app that allows using smartphones as measuring tools to conduct experiments on Physics.

  3. Coupled vibrations in horizontal and vertical rotor-bearings systems

    OpenAIRE

    Luneno, Jean-Claude

    2010-01-01

    For dynamical systems having several degrees of freedom, motion in one direction can induce motion in the other and/or vice versa. This means that there is a certain coupling between these two motions. Coupling can in some cases be a source of instability that causes self-excited vibrations in rotating machinery. In modeling hydropower rotors, couplings other than those that are the result of gyroscopic effect are normally not considered. This is due to the complexity of the reasons for coupl...

  4. Development of a tool to capture of the human movement for biometric analysis

    International Nuclear Information System (INIS)

    Chacon Taylor, Marco; Ortiz Cubero, Esteban

    2013-01-01

    A tool is developed for the measurement of stability static and dynamic of people. The Wii Remote TM was chosen as the system to capture body movement. The measurements of the gyroscopes and accelerometers are obtained from the wiimote adhered to a part of the human body. Dynamic stability parameters are calculated using the wiimote. Dynamic stability data are compared between IMU (Inertial Measurement Unit) and wiimote. The position, orientation, etc. are recreated from measurements of the wiimote. The study of new motion capture techniques is recommended for the analysis of dynamic stability [es

  5. Application of inertial sensors for motion analysis

    Directory of Open Access Journals (Sweden)

    Ferenc Soha

    2012-06-01

    Full Text Available This paper presents our results on the application of various inertial sensors for motion analysis. After the introduction of different sensor types (accelerometer, gyroscope, magnetic field sensor, we discuss the possible data collection and transfer techniques using embedded signal processing and wireless data communication methods [1,2]. Special consideration is given to the interpretation of accelerometer readings, which contains both the static and dynamic components, and is affected by the orientation and rotation of the sensor. We will demonstrate the possibility to decompose these components for quasiperiodic motions. Finally we will demonstrate the application of commercially available devices (Wii sensor, Kinect sensor, mobile phone for motion analysis applications.

  6. MEMS fundamental technology and applications

    CERN Document Server

    Choudhary, Vikas

    2013-01-01

    "The book editors have managed to assemble a group of extraordinary authors to provide their expertise to this book. While giving an excellent overview of the history and the state of the art of MEMS technology, this book also focuses on current trends and topics such as gyroscopes that currently experience significant and increasing popularity in research and in industry. It is well written and the material is presented in a well-structured way making it easily accessible to any reader with a technical background."-Boris Stoeber, The University of British Columbia, Vancouver, Canada.

  7. Integrated Optical Circuit Engineering For Optical Fiber Gyrocopes

    Science.gov (United States)

    Bristow, Julian P.; We, Albert C.; Keur, M.; Lukas, Greg; Ott, Daniel M...; Sriram, S.

    1988-03-01

    Fiber optic gyroscopes are of interest for low-cost, high performance rotation sensors. Integrated optical implementations of the processing optics offer the hope of mass-production, and associated cost reductions. The development of a suitable integrated optical system has been reported by other authors at a wavelength of 850nm [1]. Despite strong technical advantages at 1.3μm wavelength [2], no results have yet appeared. This wavelength is preferred for telecommunications applications applications, thus significantly reduced fiber costs may be realized. Lithium niobate is relatively immune from the photorefractive effect at this wavelength, whereas it is not at at 850nm [3].

  8. Image deblurring in smartphone devices using built-in inertial measurement sensors

    Science.gov (United States)

    Šindelář, Ondřej; Šroubek, Filip

    2013-01-01

    Long-exposure handheld photography is degraded with blur, which is difficult to remove without prior information about the camera motion. In this work, we utilize inertial sensors (accelerometers and gyroscopes) in modern smartphones to detect exact motion trajectory of the smartphone camera during exposure and remove blur from the resulting photography based on the recorded motion data. The whole system is implemented on the Android platform and embedded in the smartphone device, resulting in a close-to-real-time deblurring algorithm. The performance of the proposed system is demonstrated in real-life scenarios.

  9. Five years in the life of an inertial system operating in orbit

    Science.gov (United States)

    Harris, R. A.; Denhard, W. G.

    1978-01-01

    The paper describes the in-orbit performance of the gyroscopes and strapdown attitude reference system for the OAO-C (Copernicus) satellite, launched on Aug. 21, 1972. In order to fulfill NASA requirements, the inertial system had to: (1) operate for at least one year in orbit without failure, (2) maintain an inertial reference with an uncertainty of 50 microradians or less for at least one hour, and (3) control attitude changes with an accuracy of at least 30 parts per million. During the orbit period, the inertial system has demonstrated a capability for maintaining an inertial reference that is significantly better than these performance goals.

  10. Implementation Of Simulink Controller Design On IRIS+ Quadrotor

    Science.gov (United States)

    2015-09-01

    11 Table 2 PX4 Pixhawk Hardware Specifications (from [16]). Processor 32bit STM32F427 Cortex M4 core with...Microelectronics® and a Cortex M4 microprocessor running the NuttX RTOS that allows integrated multi-threading and programming in a Unix/Linux- like...FPU 168 MHz 256 KB RAM 2 MB Flash 32 bit STM32F103 failsafe co- processor Sensors ST Micro L3GD20H 16 bit gyroscope ST Micro LSM303D 14 bit

  11. Experimental Demonstration of an Algorithm to Detect the Presence of a Parasitic Satellite

    Science.gov (United States)

    2003-03-01

    Chile (FASat- Alfa/Bravo), South Africa (UoSAT-3/4/5), Thailand (TMSAT-1), Sin- 1-2 gapore (Merlion payload), and Malaysia (TiungSAT-1). Recently...original configuration. 3.3.1 Hardware. The ground-station computer has been upgraded from the original configuration to a Dell r© Dimension r© Model...1◦/ hr accuracy. This is expected to be a two order of magnitude improvement. It is approximately the same size as the current gyroscope for simple

  12. A modified precise integration method based on Magnus expansion for transient response analysis of time varying dynamical structure

    International Nuclear Information System (INIS)

    Yue, Cong; Ren, Xingmin; Yang, Yongfeng; Deng, Wangqun

    2016-01-01

    This paper provides a precise and efficacious methodology for manifesting forced vibration response with respect to the time-variant linear rotational structure subjected to unbalanced excitation. A modified algorithm based on time step precise integration method and Magnus expansion is developed for instantaneous dynamic problems. The iterative solution is achieved by the ideology of transition and dimensional increment matrix. Numerical examples on a typical accelerating rotation system considering gyroscopic moment and mass unbalance force comparatively demonstrate the validity, effectiveness and accuracy with Newmark-β method. It is shown that the proposed algorithm has high accuracy without loss efficiency.

  13. Vortex-Induced Vibrations of a Riser with Design Variations

    Science.gov (United States)

    2016-06-19

    0.283s (right plot) periods This gyroscopic effect is real, stable and has a preferred direction in much the same way that the Magnus effect does. The... Magnus effect is normally associated with the generation of a cross-flow force on a spinning cylinder in a larger fluid flow field. The Magnus force...for public release; distribution is unlimited 8 period (Figure 7) vibrates in a “figure 8” and thus does not evolve a Magnus effect . The opposing

  14. A MEMS-based Adaptive AHRS for Marine Satellite Tracking Antenna

    DEFF Research Database (Denmark)

    Wang, Yunlong; Hussain, Dil Muhammed Akbar; Soltani, Mohsen

    2015-01-01

    Satellite tracking is a challenging task for marine applications. An attitude determination system should estimate the wave disturbances on the ship body accurately. To achieve this, an Attitude Heading Reference System (AHRS) based on Micro-Electro-Mechanical Systems (MEMS) sensors, composed...... of three-axis gyroscope, accelerometer and magnetometer, is developed for Marine Satellite Tracking Antenna (MSTA). In this paper, the attitude determination algorithm is improved using an adaptive mechanism that tunes the attitude estimator parameters based on an estimation of ship motion frequency...

  15. Physiologically Modulating Videogames or Simulations which Use Motion-Sensing Input Devices

    Science.gov (United States)

    Pope, Alan T. (Inventor); Stephens, Chad L. (Inventor); Blanson, Nina Marie (Inventor)

    2017-01-01

    New types of controllers allow a player to make inputs to a video game or simulation by moving the entire controller itself or by gesturing or by moving the player's body in whole or in part. This capability is typically accomplished using a wireless input device having accelerometers, gyroscopes, and a camera. The present invention exploits these wireless motion-sensing technologies to modulate the player's movement inputs to the videogame based upon physiological signals. Such biofeedback-modulated video games train valuable mental skills beyond eye-hand coordination. These psychophysiological training technologies enhance personal improvement, not just the diversion, of the user.

  16. Parametric instabilities of rotor-support systems with application to industrial ventilators

    Science.gov (United States)

    Parszewski, Z.; Krodkiemski, T.; Marynowski, K.

    1980-01-01

    Rotor support systems interaction with parametric excitation is considered for both unequal principal shaft stiffness (generators) and offset disc rotors (ventilators). Instability regions and types of instability are computed in the first case, and parametric resonances in the second case. Computed and experimental results are compared for laboratory machine models. A field case study of parametric vibrations in industrial ventilators is reported. Computed parametric resonances are confirmed in field measurements, and some industrial failures are explained. Also the dynamic influence and gyroscopic effect of supporting structures are shown and computed.

  17. Dynamic characterization, monitoring and control of rotating flexible beam-mass structures via piezo-embedded techniques

    Science.gov (United States)

    Lai, Steven H.-Y.

    1992-01-01

    A variational principle and a finite element discretization technique were used to derive the dynamic equations for a high speed rotating flexible beam-mass system embedded with piezo-electric materials. The dynamic equation thus obtained allows the development of finite element models which accommodate both the original structural element and the piezoelectric element. The solutions of finite element models provide system dynamics needed to design a sensing system. The characterization of gyroscopic effect and damping capacity of smart rotating devices are addressed. Several simulation examples are presented to validate the analytical solution.

  18. Ultrahigh enhancement in absolute and relative rotation sensing using fast and slow light

    International Nuclear Information System (INIS)

    Shahriar, M. S.; Pati, G. S.; Tripathi, R.; Gopal, V.; Messall, M.; Salit, K.

    2007-01-01

    We describe a resonator-based optical gyroscope whose sensitivity for measuring absolute rotation is enhanced via use of the anomalous dispersion characteristic of superluminal light propagation. The enhancement is given by the inverse of the group index, saturating to a bound determined by the group velocity dispersion. We also show how the offsetting effect of the concomitant broadening of the resonator linewidth may be circumvented by using an active cavity. For realistic conditions, the enhancement factor is as high as 10 6 . We also show how normal dispersion used for slow light can enhance relative rotation sensing in a specially designed Sagnac interferometer, with the enhancement given by the slowing factor

  19. 100 years since Michelson and Morley - the quest for the ultimate interferometer

    International Nuclear Information System (INIS)

    Bachor, H.A.; McClelland, D.E.

    1989-01-01

    This paper summarise some of the achievements of optical interferometry in its 100 years of existence. It is shown how over the decades, developments in optics, lasers, electronics and quantum mechanics have led to dramatic improvements in sensitivity, with the most recent developments aiming at a δL/L of 10 -12 . In addition, digital image processing and laser stabilisation techniques were combined to analyse optical surfaces with a resolution of 1/500 of a fringe. Some of interferometer applications are discussed and these include radio astronomy, laser gyroscopes, the visualisation of flows and the diagnostic of laboratory plasmas. 18 refs., 2 figs

  20. Multifuctional integrated sensors (MFISES).

    Energy Technology Data Exchange (ETDEWEB)

    Homeijer, Brian D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Roozeboom, Clifton [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-10-01

    Many emerging IoT applications require sensing of multiple physical and environmental parameters for: completeness of information, measurement validation, unexpected demands, improved performance. For example, a typical outdoor weather station measures temperature, humidity, barometric pressure, light intensity, rainfall, wind speed and direction. Existing sensor technologies do not directly address the demand for cost, size, and power reduction in multi-paramater sensing applications. Industry sensor manufacturers have developed integrated sensor systems for inertial measurements that combine accelerometers, gyroscopes, and magnetometers, but do not address environmental sensing functionality. In existing research literature, a technology gap exists between the functionality of MEMS sensors and the real world applications of the sensors systems.

  1. Creation and development of the universe (symmetry approach)

    International Nuclear Information System (INIS)

    Zheludev, I.S.

    1993-09-01

    The model according to which space subreality and time subreality are created during Big Bang is introduced. The first one is centrosymmetrical, the second anticentrosymmetrical. One to another they are transformed by mutual ''replacement'' space and time. Such subrealities are not antisubrealities and their elementary particles (appeared through Big Bang) are not able to annihilate completely because of symmetry conditions. This leads to the appearance of condensed matter. The model of two subrealities gives the possibility to explain without ''parity violation'' any physical phenomena. Four macroscopic rules of symmetry [scale, corkscrew, gyroscope and right (left) hand] reflect four fundamental interactions of our reality. (author). 10 refs, 16 figs

  2. Force on an electric/magnetic dipole and classical approach to spin-orbit coupling in hydrogen-like atoms

    Science.gov (United States)

    Kholmetskii, A. L.; Missevitch, O. V.; Yarman, T.

    2017-09-01

    We carry out the classical analysis of spin-orbit coupling in hydrogen-like atoms, using the modern expressions for the force and energy of an electric/magnetic dipole in an electromagnetic field. We disclose a novel physical meaning of this effect and show that for a laboratory observer the energy of spin-orbit interaction is represented solely by the mechanical energy of the spinning electron (considered as a gyroscope) due to the Thomas precession of its spin. Concurrently we disclose some errors in the old and new publications on this subject.

  3. Dynamical analysis of a flywheel-superconducting bearing with a moving magnet support

    International Nuclear Information System (INIS)

    Sivrioglu, Selim; Nonami, Kenzo

    2003-01-01

    A lateral stiffness improvement approach based on a moving magnet support is developed to reduce the vibration of a flywheel rotor-high temperature superconductor (HTS) bearing. A flywheel rotor levitated with an HTS bearing is modelled and then analysed with a moving stator magnet placed above the rotor. A dynamic support principle is introduced based on moving the stator magnet in anti-phase with the rotor displacement for small variations. A complete dynamical equation of the flywheel rotor is derived including gyroscopic and imbalance effects. The simulation results showed that the dynamic support of the flywheel rotor with additional stator magnet movements decreases the vibration of the flywheel rotor considerably

  4. Modern Breakthrough Technologies Enable New Applications Based on IMU Systems

    Directory of Open Access Journals (Sweden)

    Nunzio Abbate

    2011-01-01

    Full Text Available This paper describes IMU (Inertial Measurement Unit platforms and their main target applications with a special focus on the 10-degree-of-freedom (10-DOF inertial platform iNEMO and its technical features and performances. The iNEMO module is equipped with a 3-axis MEMS accelerometer, a 3-axis MEMS gyroscope, a 3-axis MEMS magnetometer, a pressure sensor, and a temperature sensor. Furthermore, the Microcontroller Unit (MCU collects measurements by the sensors and computes the orientation through a customized Extended Kalman Filter (EKF for sensor fusion.

  5. Dependence of mis-alignment sensitivity of ring laser gyro cavity on cavity parameters

    Energy Technology Data Exchange (ETDEWEB)

    Sun Feng; Zhang Xi; Zhang Hongbo; Yang Changcheng, E-mail: sunok1234@sohu.com [Huazhong Institute of Electro-Optics - Wuhan National Lab for Optoelectronics, Wuhan, Hubei (China)

    2011-02-01

    The ring laser gyroscope (RLG), as a rotation sensor, has been widely used for navigation and guidance on vehicles and missiles. The environment of strong random-vibration and large acceleration may deteriorate the performance of the RLG due to the vibration-induced tilting of the mirrors. In this paper the RLG performance is theoretically analyzed and the parameters such as the beam diameter at the aperture, cavity mirror alignment sensitivities and power loss due to the mirror tilting are calculated. It is concluded that by carefully choosing the parameters, the significant loss in laser power can be avoided.

  6. A Nonlinear Attitude Estimator for Attitude and Heading Reference Systems Based on MEMS Sensors

    DEFF Research Database (Denmark)

    Wang, Yunlong; Soltani, Mohsen; Hussain, Dil muhammed Akbar

    2016-01-01

    In this paper, a nonlinear attitude estimator is designed for an Attitude Heading and Reference System (AHRS) based on Micro Electro-Mechanical Systems (MEMS) sensors. The design process of the attitude estimator is stated with detail, and the equilibrium point of the estimator error model...... the problems in previous research works. Moreover, the estimation of MEMS gyroscope bias is also inclueded in this estimator. The designed nonlinear attitude estimator is firstly tested in simulation environment and then implemented in an AHRS hardware for further experiments. Finally, the attitude estimation...

  7. Guided Optical Structures in the Military Environment

    Science.gov (United States)

    1986-05-01

    gyroscopes using integrated optica " (ref.9A), H.C.Lefevre, J.P. Bettini, S.Vatoux and M.Papuohon showed that considerable progress had meanwhile been made...Rotating Optical Fiber Ring Intorferometer", Applied Optica , 16, p. 2605, 1977. 7. V. Vali, R. W. Shorthill, A. Goldstein, and R. S. Krogstad, "Laser...Trmometro, a fibra ottica- Italian Patent No. 04155 A/82 (1982) under extension. 7-5 10 A.M. Sohoggi, M. Dranci, G. Conforti, R. Falcioi, G.P. Preti

  8. Roles of superconducting magnetic bearings and active magnetic bearings in attitude control and energy storage flywheel

    International Nuclear Information System (INIS)

    Tang Jiqiang; Fang Jiancheng; Ge, Shuzhi Sam

    2012-01-01

    Compared with conventional energy storage flywheel, the rotor of attitude control and energy storage flywheel (ACESF) used in space not only has high speed, but also is required to have precise and stable direction. For the presented superconducting magnetic bearing (SMB) and active magnetic bearing (AMB) suspended ACESF, the rotor model including gyroscopic couples is established originally by taking the properties of SMB and AMB into account, the forces of SMB and AMB are simplified by linearization within their own neighbors of equilibrium points. For the high-speed rigid discal rotor with large inertia, the negative effect of gyroscopic effect of rotor is prominent, the radial translation and tilting movement of rotor suspended by only SMB, SMB with equivalent PMB, or SMB together with PD controlled AMB are researched individually. These analysis results proved originally that SMB together with AMB can make the rotor be stable and make the radial amplitude of the vibration of rotor be small while the translation of rotor suspended by only SMB or SMB and PM is not stable and the amplitude of this vibration is large. For the stability of the high-speed rotor in superconducting ACESF, the AMB can suppress the nutation and precession of rotor effectively by cross-feedback control based on the separated PD type control or by other modern control methods.

  9. Triana Safehold: A New Gyroless, Sun-Pointing Attitude Controller

    Science.gov (United States)

    Chen, J.; Morgenstern, Wendy; Garrick, Joseph

    2001-01-01

    Triana is a single-string spacecraft to be placed in a halo orbit about the sun-earth Ll Lagrangian point. The Attitude Control Subsystem (ACS) hardware includes four reaction wheels, ten thrusters, six coarse sun sensors, a star tracker, and a three-axis Inertial Measuring Unit (IMU). The ACS Safehold design features a gyroless sun-pointing control scheme using only sun sensors and wheels. With this minimum hardware approach, Safehold increases mission reliability in the event of a gyroscope anomaly. In place of the gyroscope rate measurements, Triana Safehold uses wheel tachometers to help provide a scaled estimation of the spacecraft body rate about the sun vector. Since Triana nominally performs momentum management every three months, its accumulated system momentum can reach a significant fraction of the wheel capacity. It is therefore a requirement for Safehold to maintain a sun-pointing attitude even when the spacecraft system momentum is reasonably large. The tachometer sun-line rate estimation enables the controller to bring the spacecraft close to its desired sun-pointing attitude even with reasonably high system momentum and wheel drags. This paper presents the design rationale behind this gyroless controller, stability analysis, and some time-domain simulation results showing performances with various initial conditions. Finally, suggestions for future improvements are briefly discussed.

  10. Complementary filter implementation in the dynamic language Lua

    Science.gov (United States)

    Sadowski, Damian; Sawicki, Aleksander; Lukšys, Donatas; Slanina, Zdenek

    2017-08-01

    The article presents the complementary filter implementation, that is used for the estimation of the pitch angle, in Lua script language. Inertial sensors as accelerometer and gyroscope were used in the study. Methods of angles estimation using acceleration and angular velocity sensors were presented in the theoretical part of the article. The operating principle of complementary filter has been presented. The prototype of Butterworth's analogue filter and its digital equivalent have been designed. Practical implementation of the issue was performed with the use of PC and DISCOVERY evaluation board equipped with STM32F01 processor, L3GD20 gyroscope and LS303DLHC accelerometer. Measurement data was transmitted by UART serial interface, then processed with the use of Lua software and luaRS232 programming library. Practical implementation was divided into two stages. In the first part, measurement data has been recorded and then processed with help of a complementary filter. In the second step, coroutines mechanism was used to filter data in real time.

  11. Swarm Optimization-Based Magnetometer Calibration for Personal Handheld Devices

    Directory of Open Access Journals (Sweden)

    Naser El-Sheimy

    2012-09-01

    Full Text Available Inertial Navigation Systems (INS consist of accelerometers, gyroscopes and a processor that generates position and orientation solutions by integrating the specific forces and rotation rates. In addition to the accelerometers and gyroscopes, magnetometers can be used to derive the user heading based on Earth’s magnetic field. Unfortunately, the measurements of the magnetic field obtained with low cost sensors are usually corrupted by several errors, including manufacturing defects and external electro-magnetic fields. Consequently, proper calibration of the magnetometer is required to achieve high accuracy heading measurements. In this paper, a Particle Swarm Optimization (PSO-based calibration algorithm is presented to estimate the values of the bias and scale factor of low cost magnetometers. The main advantage of this technique is the use of the artificial intelligence which does not need any error modeling or awareness of the nonlinearity. Furthermore, the proposed algorithm can help in the development of Pedestrian Navigation Devices (PNDs when combined with inertial sensors and GPS/Wi-Fi for indoor navigation and Location Based Services (LBS applications.

  12. Suitability of Smartphone Inertial Sensors for Real-Time Biofeedback Applications

    Science.gov (United States)

    Kos, Anton; Tomažič, Sašo; Umek, Anton

    2016-01-01

    This article studies the suitability of smartphones with built-in inertial sensors for biofeedback applications. Biofeedback systems use various sensors to measure body functions and parameters. These sensor data are analyzed, and the results are communicated back to the user, who then tries to act on the feedback signals. Smartphone inertial sensors can be used to capture body movements in biomechanical biofeedback systems. These sensors exhibit various inaccuracies that induce significant angular and positional errors. We studied deterministic and random errors of smartphone accelerometers and gyroscopes, primarily focusing on their biases. Based on extensive measurements, we determined accelerometer and gyroscope noise models and bias variation ranges. Then, we compiled a table of predicted positional and angular errors under various biofeedback system operation conditions. We suggest several bias compensation options that are suitable for various examples of use in real-time biofeedback applications. Measurements within the developed experimental biofeedback application show that under certain conditions, even uncompensated sensors can be used for real-time biofeedback. For general use, especially for more demanding biofeedback applications, sensor biases should be compensated. We are convinced that real-time biofeedback systems based on smartphone inertial sensors are applicable to many similar examples in sports, healthcare, and other areas. PMID:26927125

  13. Cardiac and Respiratory Parameter Estimation Using Head-mounted Motion-sensitive Sensors

    Directory of Open Access Journals (Sweden)

    J. Hernandez

    2015-05-01

    Full Text Available This work explores the feasibility of using motion-sensitive sensors embedded in Google Glass, a head-mounted wearable device, to robustly measure physiological signals of the wearer. In particular, we develop new methods to use Glass’s accelerometer, gyroscope, and camera to extract pulse and respiratory waves of 12 participants during a controlled experiment. We show it is possible to achieve a mean absolute error of 0.82 beats per minute (STD: 1.98 for heart rate and 0.6 breaths per minute (STD: 1.19 for respiration rate when considering different observation windows and combinations of sensors. Moreover, we show that a head-mounted gyroscope sensor shows improved performance versus more commonly explored sensors such as accelerometers and demonstrate that a head-mounted camera is a novel and promising method to capture the physiological responses of the wearer. These findings included testing across sitting, supine, and standing postures before and after physical exercise.

  14. High-accuracy self-calibration method for dual-axis rotation-modulating RLG-INS

    Science.gov (United States)

    Wei, Guo; Gao, Chunfeng; Wang, Qi; Wang, Qun; Long, Xingwu

    2017-05-01

    Inertial navigation system has been the core component of both military and civil navigation systems. Dual-axis rotation modulation can completely eliminate the inertial elements constant errors of the three axes to improve the system accuracy. But the error caused by the misalignment angles and the scale factor error cannot be eliminated through dual-axis rotation modulation. And discrete calibration method cannot fulfill requirements of high-accurate calibration of the mechanically dithered ring laser gyroscope navigation system with shock absorbers. This paper has analyzed the effect of calibration error during one modulated period and presented a new systematic self-calibration method for dual-axis rotation-modulating RLG-INS. Procedure for self-calibration of dual-axis rotation-modulating RLG-INS has been designed. The results of self-calibration simulation experiment proved that: this scheme can estimate all the errors in the calibration error model, the calibration precision of the inertial sensors scale factor error is less than 1ppm and the misalignment is less than 5″. These results have validated the systematic self-calibration method and proved its importance for accuracy improvement of dual -axis rotation inertial navigation system with mechanically dithered ring laser gyroscope.

  15. Free (Reactionless) Torque Generation - Or Free Propulsion Concept

    International Nuclear Information System (INIS)

    Djordjev, Bojidar

    2010-01-01

    The basic principle in Newtonian Mechanics is based upon equal and opposite forces. Placing the vectors of velocity, acceleration, force and momentum of interacting objects along a single line satisfies the claim it is a linear or a 1-D concept. Classical Mechanics states that there are two main kinds of motion, linear and angular motion. Similarly placing the vectors of angular velocity, angular acceleration, torque and angular momentum along a line in the case of rotation in fact brings a plane 2-D interaction to the well known 1-D Newtonian concept. This adaptation transforms Classical Mechanics into a 1-D concept as well and presents a conformation that the linear concept is the only possible one. The Laws of Conservation of Momentum and Angular Momentum are results of the 1-D concept. But the world contains 3 geometrical spatial dimensions. Within the 3-D world there can exist 1-D, 2-D and 3-D kinds of interaction. The question is how to believe that the 3-D world can really be composed of a 1-D interaction or interactions made equal to the 1-D concept only? Examine a gyroscope - the only one mechanical device that is capable of performing 3-D behavior. The problem is that a gyroscope cannot perform three permanent and unidirectional torques that are fixed in space acting about perpendicular axes. This impossibility conforms to a 1-D concept. The idea is to find a solution that can be achieved for the 3-D concept.

  16. Fiber Sensor Technology Today

    Science.gov (United States)

    Hotate, Kazuo

    2006-08-01

    Fiber sensor technologies are overviewed. Since the early 1970s, this field has been developed, on the basis of the same devices and photonic principles as fiber communication technologies. Besides simple configurations, in which the fiber acts only as a data transmission line, sophisticated configurations have also been developed, in which the fiber is used as a device to realize unique sensing mechanisms. The fiber optic gyroscope (FOG) is a good example, and has been developed as an absolute rotation sensor used, for example, for navigation and/or attitude control applications. Compared with traditional spinning-mass gyroscopes, the FOG has advantages, such as a short warming-up time, a light weight, and easy handling. A Japanese satellite, which was launched in August 2005 with a mission to observe the aurora, is controlled with a FOG. The FOG has also been used in consumer applications, such as the camera stabilizer, radio-controlled (RC) helicopter navigation, and the control of humanoid robots. Recently, distributed and multiplexed sensing schemes, in particular, have been studied and developed, in which a long fiber acts like a “nerve” for feeling the strain and/or the temperature distribution along the fiber. Performances of artificial nerve systems have markedly improved within the last couple of years, in spatial resolution and measurement speed. By embedding the “fiber-optic nerve system” in aircraft wings, bridges and tall buildings, these materials and structures can sense damage to prevent disasters.

  17. An Orientation Sensor for Mobile Robots Using Differentials

    Directory of Open Access Journals (Sweden)

    Wei-Chen Lee

    2013-02-01

    Full Text Available Without access to external guidance, such as landmarks or beacons, indoor mobile robots usually orientate themselves by using magnetic compasses or gyroscopes. However, compasses face interference from steel furniture, and gyroscopes suffer from zero drift errors. This paper proposes an orientation sensor that can be used on differentially driven mobile robots to resolve these issues. The sensor innovatively combines the general differentials and an optical encoder so that it can provide only the orientation information. Such a sensor has not been described in any known literature and is cost-efficient compared to the common method of using two encoders for differentially driven mobile robots. The kinematic analysis and the mechanical design of this sensor are presented in this paper. The maximum mean error of the proposed orientation sensor was about 0.7° during the component tests. The application of the sensor on a vacuum cleaning robot was also demonstrated. The use of the proposed sensor may provide less uncertain orientation data for an indoor differentially driven mobile robot.

  18. Tilted wheel satellite attitude control with air-bearing table experimental results

    Science.gov (United States)

    Inumoh, Lawrence O.; Forshaw, Jason L.; Horri, Nadjim M.

    2015-12-01

    Gyroscopic actuators for satellite control have attracted significant research interest over the years, but their viability for the control of small satellites has only recently started to become clear. Research on variable speed gyroscopic actuators has long been focused on single gimbal actuators; double gimbal actuators typically operate at constant wheel spin rate and allow tilt angle ranges far larger than the ranges needed to operate most satellite missions. This research examines a tilted wheel, a newly proposed type of inertial actuator that can generate torques in all three principal axes of a rigid satellite using a spinning wheel and a double tilt mechanism. The tilt mechanism tilts the angular momentum vector about two axes providing two degree of freedom control, while variation of the wheel speed provides the third. The equations of motion of the system lead to a singularity-free system during nominal operation avoiding the need for complex steering logic. This paper describes the hardware design of the tilted wheel and the experimental setup behind both standalone and spherical air-bearing tables used to test it. Experimental results from the air bearing table are provided with the results depicting the high performance capabilities of the proposed actuator in torque generation.

  19. RANCANG BANGUN APLIKASI MONITORING DAN REKAM DATA SISTEM PENGENALAN SISTEM ISYARAT BAHASA INDONESIA BERBASIS SENSOR

    Directory of Open Access Journals (Sweden)

    Mohammad Iqbal

    2014-11-01

    Full Text Available ABSTRAK Dalam penelitian ini dikembangkan pengenalan sistem isyarat bahasa Indonesia (SIBI berbasis sensor yang diharapkan dapat memperbaiki akurasi, yaitu dengan menggunakan sensor flex untuk gerakan lekukan jari, dan menggunakan sensor accelerometer-gyroscope untuk mengetahui kemiringan/orientasi tangan. Untuk mendapatkan ekstraksi ciri dan metode pengenalan yang optimal, maka diperlukan uji coba dan analisis terhadap perbandingan ekstraksi ciri dan metode pengenalan, sehingga dapat ditentukan yang terbaik. Dalam uji coba dan analisis tersebut, maka diperlukan sampel data offline atau data yang sudah disimpan/direkam sebelumnya, sehingga diperlukan aplikasi untuk dapat merekam data (recording dan memonitoring data dari sensor-sensor yang dipasang pada sarung tangan. Dengan adanya data-data sensor tersebut, maka proses pemilihan ekstraksi ciri dan metode pengenalan yang optimal dapat dilakukan secara offline, menggunakan perangkat lunak komputasi. Capaian dapam Penelitian ini, adalah telah berhasil dikembangkan program aplikasi monitoring dan rekam data untuk sistem pengenalan SIBI. Data sensor yang dimonitoring dan direkam adalah data raw, sehingga perlu dilakukan pengolahan data untuk proses ekstraksi ciri sebelum diujicobakan pada metode pengenalan tertentu Kata kunci: SIBI, bahasa isyarat, sensor, flex, acclerometer, gyroscope, monitoring, recording.

  20. Truck-based mobile wireless sensor networks for the experimental observation of vehicle–bridge interaction

    International Nuclear Information System (INIS)

    Kim, Junhee; Lynch, Jerome P; Lee, Jong-Jae; Lee, Chang-Geun

    2011-01-01

    Heavy vehicles driving over a bridge create a complex dynamic phenomenon known as vehicle–bridge interaction. In recent years, interest in vehicle–bridge interaction has grown because a deeper understanding of the phenomena can lead to improvements in bridge design methods while enhancing the accuracy of structural health monitoring techniques. The mobility of wireless sensors can be leveraged to directly monitor the dynamic coupling between the moving vehicle and the bridge. In this study, a mobile wireless sensor network is proposed for installation on a heavy truck to capture the vertical acceleration, horizontal acceleration and gyroscopic pitching of the truck as it crosses a bridge. The vehicle-based wireless monitoring system is designed to interact with a static, permanent wireless monitoring system installed on the bridge. Specifically, the mobile wireless sensors time-synchronize with the bridge's wireless sensors before transferring the vehicle response data. Vertical acceleration and gyroscopic pitching measurements of the vehicle are combined with bridge accelerations to create a time-synchronized vehicle–bridge response dataset. In addition to observing the vehicle vibrations, Kalman filtering is adopted to accurately track the vehicle position using the measured horizontal acceleration of the vehicle and positioning information derived from piezoelectric strip sensors installed on the bridge deck as part of the bridge monitoring system. Using the Geumdang Bridge (Korea), extensive field testing of the proposed vehicle–bridge wireless monitoring system is conducted. Experimental results verify the reliability of the wireless system and the accuracy of the vehicle positioning algorithm

  1. Artist's Concept of Gravity Probe-B

    Science.gov (United States)

    2002-01-01

    Gravity Probe-B (GP-B) is the relativity experiment being developed at Stanford University to test two extraordinary predictions of Albert Einstein's general theory of relativity. The experiment will measure, very precisely, the expected tiny changes in the direction of the spin axes of four gyroscopes contained in an Earth-orbiting satellite at a 400-mile altitude. So free are the gyroscopes from disturbance that they will provide an almost perfect space-time reference system. They will measure how space and time are very slightly warped by the presence of the Earth, and, more profoundly, how the Earth's rotation very slightly drags space-time around with it. These effects, though small for the Earth, have far-reaching implications for the nature of matter and the structure of the Universe. GP-B is among the most thoroughly researched programs ever undertaken by NASA. This is the story of a scientific quest in which physicists and engineers have collaborated closely over many years. Inspired by their quest, they have invented a whole range of technologies -- technologies that are already enlivening other branches of science and engineering. Scheduled for launch in 2003 and managed for NASA by Marshall Space Flight Center, development of GP-B is the responsibility of Stanford University, with major subcontractor Lockheed Martin Corporation.

  2. Completed Gravity Probe B Undergoes Thermal Vacuum Testing

    Science.gov (United States)

    2000-01-01

    The Gravity Probe B (GP-B) is the relativity experiment developed at Stanford University to test two extraordinary predictions of Albert Einstein's general theory of relativity. The experiment will measure, very precisely, the expected tiny changes in the direction of the spin axes of four gyroscopes contained in an Earth-orbiting satellite at a 400-mile altitude. So free are the gyroscopes from disturbance that they will provide an almost perfect space-time reference system. They will measure how space and time are very slightly warped by the presence of the Earth, and, more profoundly, how the Earth's rotation very slightly drags space-time around with it. These effects, though small for the Earth, have far-reaching implications for the nature of matter and the structure of the Universe. In this photograph, the completed space vehicle is undergoing thermal vacuum environment testing. GP-B is among the most thoroughly researched programs ever undertaken by NASA. This is the story of a scientific quest in which physicists and engineers have collaborated closely over many years. Inspired by their quest, they have invented a whole range of technologies that are already enlivening other branches of science and engineering. Launched April 20, 2004 , the GP-B program was managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University along with major subcontractor Lockheed Martin Corporation. (Image credit to Russ Underwood, Lockheed Martin Corporation.)

  3. Gravity Probe B Number 4 Gyro Inspected

    Science.gov (United States)

    2000-01-01

    The Gravity Probe B (GP-B) is the relativity experiment developed at Stanford University to test two extraordinary predictions of Albert Einstein's general theory of relativity. The experiment will measure, very precisely, the expected tiny changes in the direction of the spin axes of four gyroscopes contained in an Earth-orbiting satellite at a 400-mile altitude. So free are the gyroscopes from disturbance that they will provide an almost perfect space-time reference system. They will measure how space and time are very slightly warped by the presence of the Earth, and, more profoundly, how the Earth's rotation very slightly drags space-time around with it. These effects, though small for the Earth, have far-reaching implications for the nature of matter and the structure of the Universe. In this photograph, Stanford engineer, Chris Gray, is inspecting the number 4 gyro under monochromatic light. GP-B is among the most thoroughly researched programs ever undertaken by NASA. This is the story of a scientific quest in which physicists and engineers have collaborated closely over many years. Inspired by their quest, they have invented a whole range of technologies that are already enlivening other branches of science and engineering. Launched April 20, 2004 , the GP-B program was managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University along with major subcontractor Lockheed Martin Corporation. (Image credit to Russ Leese, Stanford University.)

  4. Gravity Probe B Encapsulated

    Science.gov (United States)

    2004-01-01

    In this photo, the Gravity Probe B (GP-B) space vehicle is being encapsulated atop the Delta II launch vehicle. The GP-B is the relativity experiment developed at Stanford University to test two extraordinary predictions of Albert Einstein's general theory of relativity. The experiment will measure, very precisely, the expected tiny changes in the direction of the spin axes of four gyroscopes contained in an Earth-orbiting satellite at a 400-mile altitude. So free are the gyroscopes from disturbance that they will provide an almost perfect space-time reference system. They will measure how space and time are very slightly warped by the presence of the Earth, and, more profoundly, how the Earth's rotation very slightly drags space-time around with it. These effects, though small for the Earth, have far-reaching implications for the nature of matter and the structure of the Universe. GP-B is among the most thoroughly researched programs ever undertaken by NASA. This is the story of a scientific quest in which physicists and engineers have collaborated closely over many years. Inspired by their quest, they have invented a whole range of technologies that are already enlivening other branches of science and engineering. Launched April 20, 2004 , the GP-B program was managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University along with major subcontractor Lockheed Martin Corporation. (Image credit to Russ Underwood, Lockheed Martin Corporation).

  5. Gravity Probe B Completed With Solar Arrays

    Science.gov (United States)

    2004-01-01

    In this photo, the Gravity Probe B (GP-B) space vehicle is completed during the solar array installation. The GP-B is the relativity experiment developed at Stanford University to test two extraordinary predictions of Albert Einstein's general theory of relativity. The experiment will measure, very precisely, the expected tiny changes in the direction of the spin axes of four gyroscopes contained in an Earth-orbiting satellite at a 400-mile altitude. So free are the gyroscopes from disturbance that they will provide an almost perfect space-time reference system. They will measure how space and time are very slightly warped by the presence of the Earth, and, more profoundly, how the Earth's rotation very slightly drags space-time around with it. These effects, though small for the Earth, have far-reaching implications for the nature of matter and the structure of the Universe. GP-B is among the most thoroughly researched programs ever undertaken by NASA. This is the story of a scientific quest in which physicists and engineers have collaborated closely over many years. Inspired by their quest, they have invented a whole range of technologies that are already enlivening other branches of science and engineering. GP-B is scheduled for launch in April 2004 and managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University along with major subcontractor Lockheed Martin Corporation. (Image credit to Russ Underwood, Lockheed Martin Corporation).

  6. Gravity Probe B Space Vehicle

    Science.gov (United States)

    2003-01-01

    The space vehicle for Gravity Probe B (GP-B) arrives at the launch site at Vandenburg Air Force Base. GP-B is the relativity experiment being developed at Stanford University to test two extraordinary predictions of Albert Einstein's general theory of relativity. The experiment will measure, very precisely, the expected tiny changes in the direction of the spin axes of four gyroscopes contained in an Earth-orbiting satellite at a 400-mile altitude. So free are the gyroscopes from disturbance that they will provide an almost perfect space-time reference system. They will measure how space and time are very slightly warped by the presence of the Earth, and, more profoundly, how the Earth's rotation very slightly drags space-time around with it. These effects, though small for the Earth, have far-reaching implications for the nature of matter and the structure of the Universe. GP-B is among the most thoroughly researched programs ever undertaken by NASA. This is the story of a scientific quest in which physicists and engineers have collaborated closely over many years. Inspired by their quest, they have invented a whole range of technologies that are already enlivening other branches of science and engineering. Scheduled for launch in 2003 and managed for NASA by the Marshall Space Flight Center, development of the GP-B is the responsibility of Stanford University, with major subcontractor Lockheed Martin Corporation.

  7. An Ambulatory Method of Identifying Anterior Cruciate Ligament Reconstructed Gait Patterns

    Directory of Open Access Journals (Sweden)

    Matthew R. Patterson

    2014-01-01

    Full Text Available The use of inertial sensors to characterize pathological gait has traditionally been based on the calculation of temporal and spatial gait variables from inertial sensor data. This approach has proved successful in the identification of gait deviations in populations where substantial differences from normal gait patterns exist; such as in Parkinsonian gait. However, it is not currently clear if this approach could identify more subtle gait deviations, such as those associated with musculoskeletal injury. This study investigates whether additional analysis of inertial sensor data, based on quantification of gyroscope features of interest, would provide further discriminant capability in this regard. The tested cohort consisted of a group of anterior cruciate ligament reconstructed (ACL-R females and a group of non-injured female controls, each performed ten walking trials. Gait performance was measured simultaneously using inertial sensors and an optoelectronic marker based system. The ACL-R group displayed kinematic and kinetic deviations from the control group, but no temporal or spatial deviations. This study demonstrates that quantification of gyroscope features can successfully identify changes associated with ACL-R gait, which was not possible using spatial or temporal variables. This finding may also have a role in other clinical applications where small gait deviations exist.

  8. Human pose recovery using wireless inertial measurement units

    International Nuclear Information System (INIS)

    Lin, Jonathan F S; Kulić, Dana

    2012-01-01

    Many applications in rehabilitation and sports training require the assessment of the patient’s status based on observation of their movement. Small wireless sensors, such as accelerometers and gyroscopes, can be utilized to provide a quantitative measure of the human movement for assessment. In this paper, a kinematics-based approach is developed to estimate human leg posture and velocity from wearable sensors during the performance of typical physiotherapy and training exercises. The proposed approach uses an extended Kalman filter to estimate joint angles from accelerometer and gyroscopic data and is capable of recovering joint angles from arbitrary 3D motion. Additional joint limit constraints are implemented to reduce drift, and an automated approach is developed for estimating and adapting the process noise during online estimation. The approach is validated through a user study consisting of 20 subjects performing knee and hip rehabilitation exercises. When compared to motion capture, the approach achieves an average root-mean-square error of 4.27 cm for unconstrained motion, with an average joint error of 6.5°. The average root-mean-square error is 3.31 cm for sagittal planar motion, with an average joint error of 4.3°. (paper)

  9. Designing on-Board Data Handling for EDF (Electric Ducted Fan) Rocket

    Science.gov (United States)

    Mulyana, A.; Faiz, L. A. A.

    2018-02-01

    The EDF (Electric Ducted Fan) rocket to launch requires a system of monitoring, tracking and controlling to allow the rocket to glide properly. One of the important components in the rocket is OBDH (On-Board Data Handling) which serves as a medium to perform commands and data processing. However, TTC (Telemetry, Tracking, and Command) are required to communicate between GCS (Ground Control Station) and OBDH on EDF rockets. So the design control system of EDF rockets and GCS for telemetry and telecommand needs to be made. In the design of integrated OBDH controller uses a lot of electronics modules, to know the behavior of rocket used IMU sensor (Inertial Measurement Unit) in which consist of 3-axis gyroscope sensor and Accelerometer 3-axis. To do tracking using GPS, compass sensor as a determinant of the direction of the rocket as well as a reference point on the z-axis of gyroscope sensor processing and used barometer sensors to measure the height of the rocket at the time of glide. The data can be known in real-time by sending data through radio modules at 2.4 GHz frequency using XBee-Pro S2B to GCS. By using windows filter, noises can be reduced, and it used to guarantee monitoring and controlling system can work properly.

  10. Angular velocity and centripetal acceleration relationship

    Science.gov (United States)

    Monteiro, Martín; Cabeza, Cecilia; Marti, Arturo C.; Vogt, Patrik; Kuhn, Jochen

    2014-05-01

    During the last few years, the growing boom of smartphones has given rise to a considerable number of applications exploiting the functionality of the sensors incorporated in these devices. A sector that has unexpectedly taken advantage of the power of these tools is physics teaching, as reflected in several recent papers. In effect, the use of smartphones has been proposed in several physics experiments spanning mechanics, electromagnetism, optics, oscillations, and waves, among other subjects. Although mechanical experiments have received considerable attention, most of them are based on the use of the accelerometer. An aspect that has received less attention is the use of rotation sensors or gyroscopes. An additional advance in the use of these devices is given by the possibility of obtaining data using the accelerometer and the gyroscope simultaneously. The aim of this paper is to consider the relation between the centripetal acceleration and the angular velocity. Instead of using a formal laboratory setup, in this experiment a smartphone is attached to the floor of a merry-go-round, found in many playgrounds. Several experiments were performed with the roundabout rotating in both directions and with the smart-phone at different distances from the center. The coherence of the measurements is shown.

  11. A neural circuit for angular velocity computation

    Directory of Open Access Journals (Sweden)

    Samuel B Snider

    2010-12-01

    Full Text Available In one of the most remarkable feats of motor control in the animal world, some Diptera, such as the housefly, can accurately execute corrective flight maneuvers in tens of milliseconds. These reflexive movements are achieved by the halteres, gyroscopic force sensors, in conjunction with rapidly-tunable wing-steering muscles. Specifically, the mechanosensory campaniform sensilla located at the base of the halteres transduce and transform rotation-induced gyroscopic forces into information about the angular velocity of the fly's body. But how exactly does the fly's neural architecture generate the angular velocity from the lateral strain forces on the left and right halteres? To explore potential algorithms, we built a neuro-mechanical model of the rotation detection circuit. We propose a neurobiologically plausible method by which the fly could accurately separate and measure the three-dimensional components of an imposed angular velocity. Our model assumes a single sign-inverting synapse and formally resembles some models of directional selectivity by the retina. Using multidimensional error analysis, we demonstrate the robustness of our model under a variety of input conditions. Our analysis reveals the maximum information available to the fly given its physical architecture and the mathematics governing the rotation-induced forces at the haltere's end knob.

  12. Particle swarm optimization algorithm based low cost magnetometer calibration

    Science.gov (United States)

    Ali, A. S.; Siddharth, S., Syed, Z., El-Sheimy, N.

    2011-12-01

    Inertial Navigation Systems (INS) consist of accelerometers, gyroscopes and a microprocessor provide inertial digital data from which position and orientation is obtained by integrating the specific forces and rotation rates. In addition to the accelerometers and gyroscopes, magnetometers can be used to derive the absolute user heading based on Earth's magnetic field. Unfortunately, the measurements of the magnetic field obtained with low cost sensors are corrupted by several errors including manufacturing defects and external electro-magnetic fields. Consequently, proper calibration of the magnetometer is required to achieve high accuracy heading measurements. In this paper, a Particle Swarm Optimization (PSO) based calibration algorithm is presented to estimate the values of the bias and scale factor of low cost magnetometer. The main advantage of this technique is the use of the artificial intelligence which does not need any error modeling or awareness of the nonlinearity. The estimated bias and scale factor errors from the proposed algorithm improve the heading accuracy and the results are also statistically significant. Also, it can help in the development of the Pedestrian Navigation Devices (PNDs) when combined with the INS and GPS/Wi-Fi especially in the indoor environments

  13. Supercritical Nonlinear Vibration of a Fluid-Conveying Pipe Subjected to a Strong External Excitation

    Directory of Open Access Journals (Sweden)

    Yan-Lei Zhang

    2016-01-01

    Full Text Available Nonlinear vibration of a fluid-conveying pipe subjected to a transverse external harmonic excitation is investigated in the case with two-to-one internal resonance. The excitation amplitude is in the same magnitude of the transverse displacement. The fluid in the pipes flows in the speed larger than the critical speed so that the straight configuration becomes an unstable equilibrium and two curved configurations bifurcate as stable equilibriums. The motion measured from each of curved equilibrium configurations is governed by a nonlinear integro-partial-differential equation with variable coefficients. The Galerkin method is employed to discretize the governing equation into a gyroscopic system consisting of a set of coupled nonlinear ordinary differential equations. The method of multiple scales is applied to analyze approximately the gyroscopic system. A set of first-order ordinary differential equations governing the modulations of the amplitude and the phase are derived via the method. In the supercritical regime, the subharmonic, superharmonic, and combination resonances are examined in the presence of the 2 : 1 internal resonance. The steady-state responses and their stabilities are determined. The various jump phenomena in the amplitude-frequency response curves are demonstrated. The effects of the viscosity, the excitation amplitude, the nonlinearity, and the flow speed are observed. The analytical results are supported by the numerical integration.

  14. Estimating Orientation Using Magnetic and Inertial Sensors and Different Sensor Fusion Approaches: Accuracy Assessment in Manual and Locomotion Tasks

    Directory of Open Access Journals (Sweden)

    Elena Bergamini

    2014-10-01

    Full Text Available Magnetic and inertial measurement units are an emerging technology to obtain 3D orientation of body segments in human movement analysis. In this respect, sensor fusion is used to limit the drift errors resulting from the gyroscope data integration by exploiting accelerometer and magnetic aiding sensors. The present study aims at investigating the effectiveness of sensor fusion methods under different experimental conditions. Manual and locomotion tasks, differing in time duration, measurement volume, presence/absence of static phases, and out-of-plane movements, were performed by six subjects, and recorded by one unit located on the forearm or the lower trunk, respectively. Two sensor fusion methods, representative of the stochastic (Extended Kalman Filter and complementary (Non-linear observer filtering, were selected, and their accuracy was assessed in terms of attitude (pitch and roll angles and heading (yaw angle errors using stereophotogrammetric data as a reference. The sensor fusion approaches provided significantly more accurate results than gyroscope data integration. Accuracy improved mostly for heading and when the movement exhibited stationary phases, evenly distributed 3D rotations, it occurred in a small volume, and its duration was greater than approximately 20 s. These results were independent from the specific sensor fusion method used. Practice guidelines for improving the outcome accuracy are provided.

  15. Multi-modal intelligent seizure acquisition (MISA) system--a new approach towards seizure detection based on full body motion measures.

    Science.gov (United States)

    Conradsen, Isa; Beniczky, Sandor; Wolf, Peter; Terney, Daniella; Sams, Thomas; Sorensen, Helge B D

    2009-01-01

    Many epilepsy patients cannot call for help during a seizure, because they are unconscious or because of the affection of their motor system or speech function. This can lead to injuries, medical complications and at worst death. An alarm system setting off at seizure onset could help to avoid hazards. Today no reliable alarm systems are available. A Multi-modal Intelligent Seizure Acquisition (MISA) system based on full body motion data seems as a good approach towards detection of epileptic seizures. The system is the first to provide a full body description for epilepsy applications. Three test subjects were used for this pilot project. Each subject simulated 15 seizures and in addition performed some predefined normal activities, during a 4-hour monitoring with electromyography (EMG), accelerometer, magnetometer and gyroscope (AMG), electrocardiography (ECG), electroencephalography (EEG) and audio and video recording. The results showed that a non-subject specific MISA system developed on data from the modalities: accelerometer (ACM), gyroscope and EMG is able to detect 98% of the simulated seizures and at the same time mistakes only 4 of the normal movements for seizures. If the system is individualized (subject specific) it is able to detect all simulated seizures with a maximum of 1 false positive. Based on the results from the simulated seizures and normal movements the MISA system seems to be a promising approach to seizure detection.

  16. Skew redundant MEMS IMU calibration using a Kalman filter

    International Nuclear Information System (INIS)

    Jafari, M; Sahebjameyan, M; Moshiri, B; Najafabadi, T A

    2015-01-01

    In this paper, a novel calibration procedure for skew redundant inertial measurement units (SRIMUs) based on micro-electro mechanical systems (MEMS) is proposed. A general model of the SRIMU measurements is derived which contains the effects of bias, scale factor error and misalignments. For more accuracy, the effect of lever arms of the accelerometers to the center of the table are modeled and compensated in the calibration procedure. Two separate Kalman filters (KFs) are proposed to perform the estimation of error parameters for gyroscopes and accelerometers. The predictive error minimization (PEM) stochastic modeling method is used to simultaneously model the effect of bias instability and random walk noise on the calibration Kalman filters to diminish the biased estimations. The proposed procedure is simulated numerically and has expected experimental results. The calibration maneuvers are applied using a two-axis angle turntable in a way that the persistency of excitation (PE) condition for parameter estimation is met. For this purpose, a trapezoidal calibration profile is utilized to excite different deterministic error parameters of the accelerometers and a pulse profile is used for the gyroscopes. Furthermore, to evaluate the performance of the proposed KF calibration method, a conventional least squares (LS) calibration procedure is derived for the SRIMUs and the simulation and experimental results compare the functionality of the two proposed methods with each other. (paper)

  17. FOG Random Drift Signal Denoising Based on the Improved AR Model and Modified Sage-Husa Adaptive Kalman Filter.

    Science.gov (United States)

    Sun, Jin; Xu, Xiaosu; Liu, Yiting; Zhang, Tao; Li, Yao

    2016-07-12

    In order to reduce the influence of fiber optic gyroscope (FOG) random drift error on inertial navigation systems, an improved auto regressive (AR) model is put forward in this paper. First, based on real-time observations at each restart of the gyroscope, the model of FOG random drift can be established online. In the improved AR model, the FOG measured signal is employed instead of the zero mean signals. Then, the modified Sage-Husa adaptive Kalman filter (SHAKF) is introduced, which can directly carry out real-time filtering on the FOG signals. Finally, static and dynamic experiments are done to verify the effectiveness. The filtering results are analyzed with Allan variance. The analysis results show that the improved AR model has high fitting accuracy and strong adaptability, and the minimum fitting accuracy of single noise is 93.2%. Based on the improved AR(3) model, the denoising method of SHAKF is more effective than traditional methods, and its effect is better than 30%. The random drift error of FOG is reduced effectively, and the precision of the FOG is improved.

  18. A covariant formalism of spin precession with respect to a reference congruence

    International Nuclear Information System (INIS)

    Jonsson, Rickard

    2006-01-01

    We derive an effectively three-dimensional relativistic spin precession formalism. The formalism is applicable to any spacetime where an arbitrary timelike reference congruence of worldlines is specified. We employ what we call a stopped spin vector which is the spin vector that we would get if we momentarily make a pure boost of the spin vector to stop it relative to the congruence. Starting from the Fermi transport equation for the standard spin vector we derive a corresponding transport equation for the stopped spin vector. Employing a spacetime transport equation for a vector along a worldline, corresponding to spatial parallel transport with respect to the congruence, we can write down a precession formula for a gyroscope relative to the local spatial geometry defined by the congruence. This general approach has already been pursued by Jantzen et al (see e.g. Jantzen R T, Carini P and Bini D 1992 Ann. Phys. 215 1-50), but the algebraic form of our respective expressions differs. We are also applying the formalism to a novel type of spatial parallel transport introduced in Jonsson (2006 Class. Quantum Grav. 23 1), as well as verifying the validity of the intuitive approach of a forthcoming paper (Jonsson 2006 forthcoming) where gyroscope precession is explained entirely as a double Thomas type of effect. We also present the resulting formalism in explicit three-dimensional form (using the boldface vector notation), and give examples of applications

  19. An Enhanced Method to Estimate Heart Rate from Seismocardiography via Ensemble Averaging of Body Movements at Six Degrees of Freedom

    Directory of Open Access Journals (Sweden)

    Hyunwoo Lee

    2018-01-01

    Full Text Available Continuous cardiac monitoring has been developed to evaluate cardiac activity outside of clinical environments due to the advancement of novel instruments. Seismocardiography (SCG is one of the vital components that could develop such a monitoring system. Although SCG has been presented with a lower accuracy, this novel cardiac indicator has been steadily proposed over traditional methods such as electrocardiography (ECG. Thus, it is necessary to develop an enhanced method by combining the significant cardiac indicators. In this study, the six-axis signals of accelerometer and gyroscope were measured and integrated by the L2 normalization and multi-dimensional kineticardiography (MKCG approaches, respectively. The waveforms of accelerometer and gyroscope were standardized and combined via ensemble averaging, and the heart rate was calculated from the dominant frequency. Thirty participants (15 females were asked to stand or sit in relaxed and aroused conditions. Their SCG was measured during the task. As a result, proposed method showed higher accuracy than traditional SCG methods in all measurement conditions. The three main contributions are as follows: (1 the ensemble averaging enhanced heart rate estimation with the benefits of the six-axis signals; (2 the proposed method was compared with the previous SCG method that employs fewer-axis; and (3 the method was tested in various measurement conditions for a more practical application.

  20. Sensors and sensor systems for guidance and navigation II; Proceedings of the Meeting, Orlando, FL, Apr. 22, 23, 1992

    Science.gov (United States)

    Welch, Sharon S.

    Topics discussed in this volume include aircraft guidance and navigation, optics for visual guidance of aircraft, spacecraft and missile guidance and navigation, lidar and ladar systems, microdevices, gyroscopes, cockpit displays, and automotive displays. Papers are presented on optical processing for range and attitude determination, aircraft collision avoidance using a statistical decision theory, a scanning laser aircraft surveillance system for carrier flight operations, star sensor simulation for astroinertial guidance and navigation, autonomous millimeter-wave radar guidance systems, and a 1.32-micron long-range solid state imaging ladar. Attention is also given to a microfabricated magnetometer using Young's modulus changes in magnetoelastic materials, an integrated microgyroscope, a pulsed diode ring laser gyroscope, self-scanned polysilicon active-matrix liquid-crystal displays, the history and development of coated contrast enhancement filters for cockpit displays, and the effect of the display configuration on the attentional sampling performance. (For individual items see A93-28152 to A93-28176, A93-28178 to A93-28180)

  1. Suitability of Smartphone Inertial Sensors for Real-Time Biofeedback Applications.

    Science.gov (United States)

    Kos, Anton; Tomažič, Sašo; Umek, Anton

    2016-02-27

    This article studies the suitability of smartphones with built-in inertial sensors for biofeedback applications. Biofeedback systems use various sensors to measure body functions and parameters. These sensor data are analyzed, and the results are communicated back to the user, who then tries to act on the feedback signals. Smartphone inertial sensors can be used to capture body movements in biomechanical biofeedback systems. These sensors exhibit various inaccuracies that induce significant angular and positional errors. We studied deterministic and random errors of smartphone accelerometers and gyroscopes, primarily focusing on their biases. Based on extensive measurements, we determined accelerometer and gyroscope noise models and bias variation ranges. Then, we compiled a table of predicted positional and angular errors under various biofeedback system operation conditions. We suggest several bias compensation options that are suitable for various examples of use in real-time biofeedback applications. Measurements within the developed experimental biofeedback application show that under certain conditions, even uncompensated sensors can be used for real-time biofeedback. For general use, especially for more demanding biofeedback applications, sensor biases should be compensated. We are convinced that real-time biofeedback systems based on smartphone inertial sensors are applicable to many similar examples in sports, healthcare, and other areas.

  2. A New Localization System for Indoor Service Robots in Low Luminance and Slippery Indoor Environment Using Afocal Optical Flow Sensor Based Sensor Fusion

    Directory of Open Access Journals (Sweden)

    Dong-Hoon Yi

    2018-01-01

    Full Text Available In this paper, a new localization system utilizing afocal optical flow sensor (AOFS based sensor fusion for indoor service robots in low luminance and slippery environment is proposed, where conventional localization systems do not perform well. To accurately estimate the moving distance of a robot in a slippery environment, the robot was equipped with an AOFS along with two conventional wheel encoders. To estimate the orientation of the robot, we adopted a forward-viewing mono-camera and a gyroscope. In a very low luminance environment, it is hard to conduct conventional feature extraction and matching for localization. Instead, the interior space structure from an image and robot orientation was assessed. To enhance the appearance of image boundary, rolling guidance filter was applied after the histogram equalization. The proposed system was developed to be operable on a low-cost processor and implemented on a consumer robot. Experiments were conducted in low illumination condition of 0.1 lx and carpeted environment. The robot moved for 20 times in a 1.5 × 2.0 m square trajectory. When only wheel encoders and a gyroscope were used for robot localization, the maximum position error was 10.3 m and the maximum orientation error was 15.4°. Using the proposed system, the maximum position error and orientation error were found as 0.8 m and within 1.0°, respectively.

  3. A New Localization System for Indoor Service Robots in Low Luminance and Slippery Indoor Environment Using Afocal Optical Flow Sensor Based Sensor Fusion.

    Science.gov (United States)

    Yi, Dong-Hoon; Lee, Tae-Jae; Cho, Dong-Il Dan

    2018-01-10

    In this paper, a new localization system utilizing afocal optical flow sensor (AOFS) based sensor fusion for indoor service robots in low luminance and slippery environment is proposed, where conventional localization systems do not perform well. To accurately estimate the moving distance of a robot in a slippery environment, the robot was equipped with an AOFS along with two conventional wheel encoders. To estimate the orientation of the robot, we adopted a forward-viewing mono-camera and a gyroscope. In a very low luminance environment, it is hard to conduct conventional feature extraction and matching for localization. Instead, the interior space structure from an image and robot orientation was assessed. To enhance the appearance of image boundary, rolling guidance filter was applied after the histogram equalization. The proposed system was developed to be operable on a low-cost processor and implemented on a consumer robot. Experiments were conducted in low illumination condition of 0.1 lx and carpeted environment. The robot moved for 20 times in a 1.5 × 2.0 m square trajectory. When only wheel encoders and a gyroscope were used for robot localization, the maximum position error was 10.3 m and the maximum orientation error was 15.4°. Using the proposed system, the maximum position error and orientation error were found as 0.8 m and within 1.0°, respectively.

  4. Expansion of Smartwatch Touch Interface from Touchscreen to Around Device Interface Using Infrared Line Image Sensors

    Directory of Open Access Journals (Sweden)

    Soo-Chul Lim

    2015-07-01

    Full Text Available Touchscreen interaction has become a fundamental means of controlling mobile phones and smartwatches. However, the small form factor of a smartwatch limits the available interactive surface area. To overcome this limitation, we propose the expansion of the touch region of the screen to the back of the user’s hand. We developed a touch module for sensing the touched finger position on the back of the hand using infrared (IR line image sensors, based on the calibrated IR intensity and the maximum intensity region of an IR array. For complete touch-sensing solution, a gyroscope installed in the smartwatch is used to read the wrist gestures. The gyroscope incorporates a dynamic time warping gesture recognition algorithm for eliminating unintended touch inputs during the free motion of the wrist while wearing the smartwatch. The prototype of the developed sensing module was implemented in a commercial smartwatch, and it was confirmed that the sensed positional information of the finger when it was used to touch the back of the hand could be used to control the smartwatch graphical user interface. Our system not only affords a novel experience for smartwatch users, but also provides a basis for developing other useful interfaces.

  5. Expansion of Smartwatch Touch Interface from Touchscreen to Around Device Interface Using Infrared Line Image Sensors.

    Science.gov (United States)

    Lim, Soo-Chul; Shin, Jungsoon; Kim, Seung-Chan; Park, Joonah

    2015-07-09

    Touchscreen interaction has become a fundamental means of controlling mobile phones and smartwatches. However, the small form factor of a smartwatch limits the available interactive surface area. To overcome this limitation, we propose the expansion of the touch region of the screen to the back of the user's hand. We developed a touch module for sensing the touched finger position on the back of the hand using infrared (IR) line image sensors, based on the calibrated IR intensity and the maximum intensity region of an IR array. For complete touch-sensing solution, a gyroscope installed in the smartwatch is used to read the wrist gestures. The gyroscope incorporates a dynamic time warping gesture recognition algorithm for eliminating unintended touch inputs during the free motion of the wrist while wearing the smartwatch. The prototype of the developed sensing module was implemented in a commercial smartwatch, and it was confirmed that the sensed positional information of the finger when it was used to touch the back of the hand could be used to control the smartwatch graphical user interface. Our system not only affords a novel experience for smartwatch users, but also provides a basis for developing other useful interfaces.

  6. An improved measurement system for FOG pure lag time with no changing of FOG work status

    Science.gov (United States)

    Chen, X.; Yang, J. H.; Zhou, Y. L.; Shu, X. W.

    2018-05-01

    The minimum pure lag time is an important factor for characterizing the dynamic performance of fiber optical gyroscope. It is defined as the time duration from the reception of velocity-shock signal to the output of corresponding fiber-optic gyroscope data. Many engineering projects have required for this index specifically, so the measurement of the minimum pure lag time is highly demanded. In typically measurement system, the work status of tested FOG has to be changed. In this work, a FOG pure lag time measurement system without changing the work status of the FOG has been demonstrated. During the operation of this test system, the impact structure generated a shock towards the FOG, and the pure lag time was measured through data processing analysis. The design scheme and test principle have been researched and analyzed in detail. And a prototype has been developed and used for experiment successfully. This measurement system can realize a measurement accuracy of better than ±3 μs and a system resolution of 108.6ns.

  7. Analysis and wafer-level design of a high-order silicon vibration isolator for resonating MEMS devices

    International Nuclear Information System (INIS)

    Yoon, Sang Won; Lee, Sangwoo; Najafi, Khalil; Perkins, Noel C

    2011-01-01

    This paper presents the analysis and preliminary design, fabrication, and measurement for mechanical vibration-isolation platforms especially designed for resonating MEMS devices including gyroscopes. Important parameters for designing isolation platforms are specified and the first platform (in designs with cascaded multiple platforms) is crucial for improving vibration-isolation performance and minimizing side-effects on integrated gyroscopes. This isolation platform, made from a thick silicon wafer substrate for an environment-resistant MEMS package, incorporates the functionalities of a previous design including vacuum packaging and thermal resistance with no additional resources. This platform consists of platform mass, isolation beams, vertical feedthroughs, and bonding pads. Two isolation platform designs follow from two isolation beam designs: lateral clamped–clamped beams and vertical torsion beams. The beams function simultaneously as mechanical springs and electrical interconnects. The vibration-isolation platform can yield a multi-dimensional, high-order mechanical low pass filter. The isolation platform possesses eight interconnects within a 12.2 × 12.2 mm 2 footprint. The contact resistance ranges from 4–11 Ω depending on the beam design. Vibration measurements using a laser-Doppler vibrometer demonstrate that the lateral vibration-isolation platform suppresses external vibration having frequencies exceeding 2.1 kHz.

  8. A Vehicle Steering Recognition System Based on Low-Cost Smartphone Sensors

    Directory of Open Access Journals (Sweden)

    Xinhua Liu

    2017-03-01

    Full Text Available Recognizing how a vehicle is steered and then alerting drivers in real time is of utmost importance to the vehicle and driver’s safety, since fatal accidents are often caused by dangerous vehicle maneuvers, such as rapid turns, fast lane-changes, etc. Existing solutions using video or in-vehicle sensors have been employed to identify dangerous vehicle maneuvers, but these methods are subject to the effects of the environmental elements or the hardware is very costly. In the mobile computing era, smartphones have become key tools to develop innovative mobile context-aware systems. In this paper, we present a recognition system for dangerous vehicle steering based on the low-cost sensors found in a smartphone: i.e., the gyroscope and the accelerometer. To identify vehicle steering maneuvers, we focus on the vehicle’s angular velocity, which is characterized by gyroscope data from a smartphone mounted in the vehicle. Three steering maneuvers including turns, lane-changes and U-turns are defined, and a vehicle angular velocity matching algorithm based on Fast Dynamic Time Warping (FastDTW is adopted to recognize the vehicle steering. The results of extensive experiments show that the average accuracy rate of the presented recognition reaches 95%, which implies that the proposed smartphone-based method is suitable for recognizing dangerous vehicle steering maneuvers.

  9. Research on Robot Pose Control Technology Based on Kinematics Analysis Model

    Science.gov (United States)

    Liu, Dalong; Xu, Lijuan

    2018-01-01

    In order to improve the attitude stability of the robot, proposes an attitude control method of robot based on kinematics analysis model, solve the robot walking posture transformation, grasping and controlling the motion planning problem of robot kinematics. In Cartesian space analytical model, using three axis accelerometer, magnetometer and the three axis gyroscope for the combination of attitude measurement, the gyroscope data from Calman filter, using the four element method for robot attitude angle, according to the centroid of the moving parts of the robot corresponding to obtain stability inertia parameters, using random sampling RRT motion planning method, accurate operation to any position control of space robot, to ensure the end effector along a prescribed trajectory the implementation of attitude control. The accurate positioning of the experiment is taken using MT-R robot as the research object, the test robot. The simulation results show that the proposed method has better robustness, and higher positioning accuracy, and it improves the reliability and safety of robot operation.

  10. Observability-Based Guidance and Sensor Placement

    Science.gov (United States)

    Hinson, Brian T.

    Control system performance is highly dependent on the quality of sensor information available. In a growing number of applications, however, the control task must be accomplished with limited sensing capabilities. This thesis addresses these types of problems from a control-theoretic point-of-view, leveraging system nonlinearities to improve sensing performance. Using measures of observability as an information quality metric, guidance trajectories and sensor distributions are designed to improve the quality of sensor information. An observability-based sensor placement algorithm is developed to compute optimal sensor configurations for a general nonlinear system. The algorithm utilizes a simulation of the nonlinear system as the source of input data, and convex optimization provides a scalable solution method. The sensor placement algorithm is applied to a study of gyroscopic sensing in insect wings. The sensor placement algorithm reveals information-rich areas on flexible insect wings, and a comparison to biological data suggests that insect wings are capable of acting as gyroscopic sensors. An observability-based guidance framework is developed for robotic navigation with limited inertial sensing. Guidance trajectories and algorithms are developed for range-only and bearing-only navigation that improve navigation accuracy. Simulations and experiments with an underwater vehicle demonstrate that the observability measure allows tuning of the navigation uncertainty.

  11. Motion Intention Analysis-Based Coordinated Control for Amputee-Prosthesis Interaction

    Directory of Open Access Journals (Sweden)

    Fei Wang

    2010-01-01

    Full Text Available To study amputee-prosthesis (AP interaction, a novel reconfigurable biped robot was designed and fabricated. In homogeneous configuration, two identical artificial legs (ALs were used to simulate the symmetrical lower limbs of a healthy person. Linear inverted pendulum model combining with ZMP stability criterion was used to generate the gait trajectories of ALs. To acquire interjoint coordination for healthy gait, rate gyroscopes were mounted on CoGs of thigh and shank of both legs. By employing principal component analysis, the measured angular velocities were processed and the motion synergy was obtained in the final. Then, one of two ALs was replaced by a bionic leg (BL, and the biped robot was changed into heterogeneous configuration to simulate the AP coupling system. To realize symmetrical stable walking, master/slave coordinated control strategy is proposed. According to information acquired by gyroscopes, BL recognized the motion intention of AL and reconstructed its kinematic variables based on interjoint coordination. By employing iterative learning control, gait tracking of BL to AL was archived. Real environment robot walking experiments validated the correctness and effectiveness of the proposed scheme.

  12. Expansion of Smartwatch Touch Interface from Touchscreen to Around Device Interface Using Infrared Line Image Sensors

    Science.gov (United States)

    Lim, Soo-Chul; Shin, Jungsoon; Kim, Seung-Chan; Park, Joonah

    2015-01-01

    Touchscreen interaction has become a fundamental means of controlling mobile phones and smartwatches. However, the small form factor of a smartwatch limits the available interactive surface area. To overcome this limitation, we propose the expansion of the touch region of the screen to the back of the user’s hand. We developed a touch module for sensing the touched finger position on the back of the hand using infrared (IR) line image sensors, based on the calibrated IR intensity and the maximum intensity region of an IR array. For complete touch-sensing solution, a gyroscope installed in the smartwatch is used to read the wrist gestures. The gyroscope incorporates a dynamic time warping gesture recognition algorithm for eliminating unintended touch inputs during the free motion of the wrist while wearing the smartwatch. The prototype of the developed sensing module was implemented in a commercial smartwatch, and it was confirmed that the sensed positional information of the finger when it was used to touch the back of the hand could be used to control the smartwatch graphical user interface. Our system not only affords a novel experience for smartwatch users, but also provides a basis for developing other useful interfaces. PMID:26184202

  13. Review of the Usefulness of Various Rotational Seismometers with Laboratory Results of Fibre-Optic Ones Tested for Engineering Applications

    Directory of Open Access Journals (Sweden)

    Leszek R. Jaroszewicz

    2016-12-01

    Full Text Available Starting with descriptions of rotational seismology, areas of interest and historical field measurements, the fundamental requirements for rotational seismometers for seismological and engineering application are formulated. On the above basis, a review of all existing rotational seismometers is presented with a description of the principles of their operation as well as possibilities to fulfill formulated requirements. This review includes mechanical, acoustical, electrochemical and optical devices and shows that the last of these types are the most promising. It is shown that optical rotational seismometer based on the ring-laser gyroscope concept is the best for seismological applications, whereas systems based on fiber-optic gyroscopes demonstrate parameters which are also required for engineering applications. Laboratory results of the Fibre-Optic System for Rotational Events & Phenomena Monitoring using a small 1-D shaking table modified to generate rotational excitations are presented. The harmonic and time-history tests demonstrate its usefulness for recording rotational motions with rates up to 0.25 rad/s.

  14. Generalizing optical geometry

    International Nuclear Information System (INIS)

    Jonsson, Rickard; Westman, Hans

    2006-01-01

    We show that by employing the standard projected curvature as a measure of spatial curvature, we can make a certain generalization of optical geometry (Abramowicz M A and Lasota J-P 1997 Class. Quantum Grav. A 14 23-30). This generalization applies to any spacetime that admits a hypersurface orthogonal shearfree congruence of worldlines. This is a somewhat larger class of spacetimes than the conformally static spacetimes assumed in standard optical geometry. In the generalized optical geometry, which in the generic case is time dependent, photons move with unit speed along spatial geodesics and the sideways force experienced by a particle following a spatially straight line is independent of the velocity. Also gyroscopes moving along spatial geodesics do not precess (relative to the forward direction). Gyroscopes that follow a curved spatial trajectory precess according to a very simple law of three-rotation. We also present an inertial force formalism in coordinate representation for this generalization. Furthermore, we show that by employing a new sense of spatial curvature (Jonsson R 2006 Class. Quantum Grav. 23 1)) closely connected to Fermat's principle, we can make a more extensive generalization of optical geometry that applies to arbitrary spacetimes. In general this optical geometry will be time dependent, but still geodesic photons move with unit speed and follow lines that are spatially straight in the new sense. Also, the sideways experienced (comoving) force on a test particle following a line that is straight in the new sense will be independent of the velocity

  15. Indoor integrated navigation and synchronous data acquisition method for Android smartphone

    Science.gov (United States)

    Hu, Chunsheng; Wei, Wenjian; Qin, Shiqiao; Wang, Xingshu; Habib, Ayman; Wang, Ruisheng

    2015-08-01

    Smartphones are widely used at present. Most smartphones have cameras and kinds of sensors, such as gyroscope, accelerometer and magnet meter. Indoor navigation based on smartphone is very important and valuable. According to the features of the smartphone and indoor navigation, a new indoor integrated navigation method is proposed, which uses MEMS (Micro-Electro-Mechanical Systems) IMU (Inertial Measurement Unit), camera and magnet meter of smartphone. The proposed navigation method mainly involves data acquisition, camera calibration, image measurement, IMU calibration, initial alignment, strapdown integral, zero velocity update and integrated navigation. Synchronous data acquisition of the sensors (gyroscope, accelerometer and magnet meter) and the camera is the base of the indoor navigation on the smartphone. A camera data acquisition method is introduced, which uses the camera class of Android to record images and time of smartphone camera. Two kinds of sensor data acquisition methods are introduced and compared. The first method records sensor data and time with the SensorManager of Android. The second method realizes open, close, data receiving and saving functions in C language, and calls the sensor functions in Java language with JNI interface. A data acquisition software is developed with JDK (Java Development Kit), Android ADT (Android Development Tools) and NDK (Native Development Kit). The software can record camera data, sensor data and time at the same time. Data acquisition experiments have been done with the developed software and Sumsang Note 2 smartphone. The experimental results show that the first method of sensor data acquisition is convenient but lost the sensor data sometimes, the second method is much better in real-time performance and much less in data losing. A checkerboard image is recorded, and the corner points of the checkerboard are detected with the Harris method. The sensor data of gyroscope, accelerometer and magnet meter have

  16. Jet Engine Bird Ingestion Simulations: Comparison of Rotating to Non-Rotating Fan Blades

    Science.gov (United States)

    Howard, Samuel A.; Hammer, Jeremiah T.; Carney, Kelly S.; Pereira, J. Michael

    2013-01-01

    Bird strike events in commercial airliners are a fairly common occurrence. According to data collected by the US Department of Agriculture, over 80,000 bird strikes were reported in the period 1990 to 2007 in the US alone (Ref. 1). As a result, bird ingestion is an important factor in aero engine design and FAA certification. When it comes to bird impacts on engine fan blades, the FAA requires full-scale bird ingestion tests on an engine running at full speed to pass certification requirements. These rotating tests are complex and very expensive. To reduce development costs associated with new materials for fan blades, it is desirable to develop more cost effective testing procedures than full-scale rotating engine tests for material evaluation. An impact test on a nonrotating single blade that captures most of the salient physics of the rotating test would go a long way towards enabling large numbers of evaluative material screening tests. NASA Glenn Research Center has been working to identify a static blade test procedure that would be effective at reproducing similar results as seen in rotating tests. The current effort compares analytical simulations of a bird strike on various non-rotating blades to a bird strike simulation on a rotating blade as a baseline case. Several different concepts for simulating the rotating loads on a non-rotating blade were analyzed with little success in duplicating the deformation results seen in the rotating case. The rotating blade behaves as if it were stiffer than the non-rotating blade resulting in less plastic deformation from a given bird impact. The key factor limiting the success of the non-rotating blade simulations is thought to be the effect of gyroscopics. Prior to this effort, it was anticipated the difficulty would be in matching the prestress in the blade due to centrifugal forces Additional work is needed to verify this assertion, and to determine if a static test procedure can simulate the gyroscopic effects in

  17. Analysis of entry accelerometer data: A case study of Mars Pathfinder

    Science.gov (United States)

    Withers, Paul; Towner, M. C.; Hathi, B.; Zarnecki, J. C.

    2003-08-01

    Accelerometers are regularly flown on atmosphere-entering spacecraft. Using their measurements, the spacecraft trajectory and the vertical structure of density, pressure, and temperature in the atmosphere through which it descends can be calculated. We review the general procedures for trajectory and atmospheric structure reconstruction and outline them here in detail. We discuss which physical properties are important in atmospheric entry, instead of working exclusively with the dimensionless numbers of fluid dynamics. Integration of the equations of motion governing the spacecraft trajectory is carried out in a novel and general formulation. This does not require an axisymmetric gravitational field or many of the other assumptions that are present in the literature. We discuss four techniques - head-on, drag-only, acceleration ratios, and gyroscopes - for constraining spacecraft attitude, which is the critical issue in the trajectory reconstruction. The head-on technique uses an approximate magnitude and direction for the aerodynamic acceleration, whereas the drag-only technique uses the correct magnitude and an approximate direction. The acceleration ratios technique uses the correct magnitude and an indirect way of finding the correct direction and the gyroscopes technique uses the correct magnitude and a direct way of finding the correct direction. The head-on and drag-only techniques are easy to implement and require little additional information. The acceleration ratios technique requires extensive and expensive aerodynamic modelling. The gyroscopes technique requires additional onboard instrumentation. The effects of errors are briefly addressed. Our implementations of these trajectory reconstruction procedures have been verified on the Mars Pathfinder dataset. We find inconsistencies within the published work of the Pathfinder science team, and in the PDS archive itself, relating to the entry state of the spacecraft. Our atmospheric structure

  18. Recognizing upper limb movements with wrist worn inertial sensors using k-means clustering classification.

    Science.gov (United States)

    Biswas, Dwaipayan; Cranny, Andy; Gupta, Nayaab; Maharatna, Koushik; Achner, Josy; Klemke, Jasmin; Jöbges, Michael; Ortmann, Steffen

    2015-04-01

    In this paper we present a methodology for recognizing three fundamental movements of the human forearm (extension, flexion and rotation) using pattern recognition applied to the data from a single wrist-worn, inertial sensor. We propose that this technique could be used as a clinical tool to assess rehabilitation progress in neurodegenerative pathologies such as stroke or cerebral palsy by tracking the number of times a patient performs specific arm movements (e.g. prescribed exercises) with their paretic arm throughout the day. We demonstrate this with healthy subjects and stroke patients in a simple proof of concept study in which these arm movements are detected during an archetypal activity of daily-living (ADL) - 'making-a-cup-of-tea'. Data is collected from a tri-axial accelerometer and a tri-axial gyroscope located proximal to the wrist. In a training phase, movements are initially performed in a controlled environment which are represented by a ranked set of 30 time-domain features. Using a sequential forward selection technique, for each set of feature combinations three clusters are formed using k-means clustering followed by 10 runs of 10-fold cross validation on the training data to determine the best feature combinations. For the testing phase, movements performed during the ADL are associated with each cluster label using a minimum distance classifier in a multi-dimensional feature space, comprised of the best ranked features, using Euclidean or Mahalanobis distance as the metric. Experiments were performed with four healthy subjects and four stroke survivors and our results show that the proposed methodology can detect the three movements performed during the ADL with an overall average accuracy of 88% using the accelerometer data and 83% using the gyroscope data across all healthy subjects and arm movement types. The average accuracy across all stroke survivors was 70% using accelerometer data and 66% using gyroscope data. We also use a Linear

  19. Highly sensitive rotation sensing based on orthogonal fiber-optic structures

    Science.gov (United States)

    Yang, Yi; Wang, Zi-nan; Xu, Lian-yu; Wang, Cui-yun; Jia, Lei; Yu, Xiao-qi; Shao, Shan; Li, Zheng-bin

    2011-08-01

    In traditional fiber-optic gyroscopes (FOG), the polarization state of counter propagating waves is critically controlled, and only the mode polarized along one particular direction survives. This is important for a traditional single mode fiber gyroscope as the requirement of reciprocity. However, there are some fatal defects such as low accuracy and poor bias stability in traditional structures. In this paper, based on the idea of polarization multiplexing, a double-polarization structure is put forward and experimentally studied. In highly birefringent fibers or standard single mode fibers with induced anisotropy, two orthogonal polarization modes can be used at the same time. Therefore, in polarization maintaining fibers (PMF), each pair of counter propagating beams preserve reciprocity within their own polarization state. Two series of sensing results are gotten in the fast and slow axes in PMF. The two sensing results have their own systematic drifts and the correlation of random noise in them is approximately zero. So, beams in fast and slow axes work as two independent and orthogonal gyroscopes. In this way, amount of information is doubled, providing opportunity to eliminate noise and improve sensitivity. Theoretically, this double-polarization structure can achieve a sensitivity of 10-18 deg/h. Computer simulation demonstrates that random noise and systematic drifts are largely reduced in this novel structure. In experiment, a forty-hour stability test targeting the earth's rotation velocity is carried out. Experiment result shows that the orthogonal fiber-optic structure has two big advantages compared with traditional ones. Firstly, the structure gets true value without any bias correction in any axis and even time-varying bias does not affect the acquisition of true value. The unbiasedness makes the structure very attractive when sudden disturbances or temperature drifts existing in working environment. Secondly, the structure lowers bias for more than

  20. Classical mechanics with calculus of variations and optimal control an intuitive introduction

    CERN Document Server

    Levi, Mark

    2014-01-01

    This is an intuitively motivated presentation of many topics in classical mechanics and related areas of control theory and calculus of variations. All topics throughout the book are treated with zero tolerance for unrevealing definitions and for proofs which leave the reader in the dark. Some areas of particular interest are: an extremely short derivation of the ellipticity of planetary orbits; a statement and an explanation of the "tennis racket paradox"; a heuristic explanation (and a rigorous treatment) of the gyroscopic effect; a revealing equivalence between the dynamics of a particle and statics of a spring; a short geometrical explanation of Pontryagin's Maximum Principle, and more. In the last chapter, aimed at more advanced readers, the Hamiltonian and the momentum are compared to forces in a certain static problem. This gives a palpable physical meaning to some seemingly abstract concepts and theorems. With minimal prerequisites consisting of basic calculus and basic undergraduate physics, this boo...