Type i and type ii micromachined vibratory gyroscopes uci. Thesis 1 mems vibratory gyroscope and readout circuit 1. Gyroscope the gyroscope references the feynman lectures on physics, chapter 20 a very nice, intuitive description of the operation of the gyroscope. Us61644a balanced vibratory gyroscope and amplitude. A vibrating structure gyroscope functions much like the halteres of flies insects in the order diptera. Active structural error suppression in mems vibratory rate. Mems vibratory gyroscopes is a must have book for engineers in both industry and academia who specialize in the design and manufacture of gyroscopes. Readout techniques for highq micromachined vibratory rate. Effect of temperature on mems vibratory rate gyroscope. Readout techniques for highq micromachined vibratory rate gyroscopes by chinwuba david ezekwe doctor of philosophy in engineering electrical engineering and computer sciences university of california, berkeley professor bernhard e. Systematic control design method exemplarily carried out for capacitive gyros. A mems gyroscope is a micromachined inertial device that can measure the angle of orientation or the angular rate of rotation. Mems gyroscopes, or strictly speaking mems angular rate sensors, are used whenever rate of turn s sensing is required without a fixed point of reference. Ring gyroscopes are believed to be relatively vibrationinsensitive because the vibration modes utilized during gyro operation are decoupled from the modes excited by environmental vibration.
Pdf simulation of the mems vibratory gyroscope through simulink. Introduction technically speaking, gyroscopes are instruments fo r measuring the rotation rate of a rigid element. Fab rication methods of mems technology have made possible to construct gyroscopes in very compact sizes. Modelling of mems vibratory gyroscopes utilizing phase detection. Design and simulation of mems comb vibratory gyroscope open. Coriolis vibratory gyroscopes cvgs can be divided into two classes according to the nature of the two vibration modes involved, per the ieee std 1431 1. A vibrator comprising a base part at least one of whose ends is fixed, a first leg extending in a direction crossing this base part, a second leg extending in a direction crossing the base part and being opposed to said first leg with respect to said base part, a first bendingvibration piece extending in a direction crossing said first leg, a second bendingvibration piece extending in a. Vibration sensitivity analysis of mems vibratory ring gyroscopes. Silicon sensings mems gyros all use the same unique patented vsg resonating ring.
Modelbased control concepts for vibratory mems gyroscopes. All vibratory gyroscopes use the coriolis acceleration that arises in rotating reference. Vibratory gyroscopes generate momentum by vibrating structures again, conservation of momentum leads to mechanisms for measuring rotation rate and orientation example. Micromechanical vibratory gyroscopes or angular rate sensors have a large potential for different types of applications as primary information sensors for guidance, control and navigation systems.
Pdf simulation of the mems vibratory gyroscope through. Pdf temperature and humidity effects on mems vibratory. Control of mems coriolis vibratory gyroscopes eeweb. A dynamical envelope model for vibratory gyroscopes. Design and development of a 3axis micro gyroscope with. The main example of mems class i cvg is the dual mass tuning fork gyro tfg. Technically speaking, gyroscopes are instruments fo r measuring the rotation rate of a rigid element. Pdf a study on resonant frequency and q factor tunings for. Vibratory gyroscopes basic vibratory gyroscope operation. Control of mems coriolis vibratory gyroscopes zurich instruments. Oct 27, 2016 this article discusses the various control mechanisms for mems coriolis vibratory gyroscopes cvg, and how they can be applied with the commercial offtheshelf hf2li lockin amplifier. The micromachined gyroscopes of this class are expected to. Vibratory gyroscope an instrument for determining the angular velocity of an object. In practical implementations of vibratory rate gyroscopes stabilization of the drivemode velocity is desired to reduce the effect of manufacturing tolerances and operational conditions on the scale factor of the sensor.
A vibrating structure gyroscope functions much like the halteres of flies insects in the order diptera the underlying physical principle is that a vibrating object tends to continue vibrating in the same plane even. Mems vibratory gyroscopes structural approaches to improve robustness cenk acar and andrei shkel isbn. Pdf a study on resonant frequency and q factor tunings. Kugi, a dynamical envelope model for vibratory gyroscopes, microsystem chnoloetgies, vol. Among different kinds of mems gyroscopes, electrostatic driving, capacitance sensing microgyroscope is a very attractive category 45. Optimized startup strategy, quadrature compensation and force feedback control being discussed. Us6046531a vibrator, vibratory gyroscope, and linear.
Theory a gyroscope is defined as a rigid rotating object, symmetric about one axis. Design and fabrication, are the tuning fork gyroscope and the vibrating ring. Its sensing element is a vibrator consisting of bars, an elastic torsion bar that joins the bars to the base of the vibrator, and a plate that is rigidly attached to the torsion bar and that moves within the field of the coils, which are mounted on the. Designs that were used to produce micromechanical gyroscopes are shown in. This separates gyros from any other means of measuring rotation, such as a tachometer or potentiometer. Request pdf on sep 1, 2009, cenk acar and others published mems vibratory gyroscopes find, read and cite all the research you need on researchgate.
In order to understand how the hf2li digital lockin amplifier is used for gyroscope applications, it is helpful to explain the internal structure of the instrument. Thesis 1 mems vibratory gyroscope and readout circuit. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. A vibrating structure gyroscope, defined by the ieee as a coriolis vibratory gyroscope cvg, is a gyroscope that uses a vibrating structure to determine the rate of rotation. A study on resonant frequency and q factor tunings for mems vibratory gyroscopes article pdf available in journal of micromechanics and microengineering 1411. The proof mass used in the design enables the reduction of damping effect. In a tuning fork device, there is a transfer of energy between two flexural modes of a proofmass held in place via suspension springs. In the class i, the two coriolis force coupled modes are different. Design and analysis of a mems comb vibratory gyroscope.
Kugi, modelbased control concepts for vibratory mems gyroscopes, mechatronics,22,3,241250,2012. A balanced vibratory microgyroscope having an electrode pattern having four inner drive electrodes and four outer sense electrodes for providing balanced pushpull control of a cloverleaf microgyroscope. Request pdf effect of temperature on mems vibratory rate gyroscope we report the temperature dependence of the jplboeing mems second generation post resonator gyroscopes and determine the. Vibration sensitivity analysis of mems vibratory ring. Control of mems coriolis vibratory gyroscopes eeweb community.
Fabrication defects and perturbations affect the behavior of a vibratory mems gyroscope sensor, which makes it difficult to measure the rotation angular rate. All vibratory gyroscopes are based on the transfer of energy. Mems vibratory gyroscopes are increasingly used in applications ranging from consumer electronics to aerospace and are now one of the most common mems products after accelerometers. James objectives to qualitatively observe some of the motions of a gyroscope. Sep 18, 20 in reality, in order to improve the loop control accuracy, an integral function is imported into the controller of the closedloop, and the agcpi closedloop structure is widely used in the driving circuit of mems vibratory gyroscopes which is a 3rd order system.
However, a purely feedback control can be insufficient for compensation of all the errors, requiring post processing in the form of laser trimming to achieve higher levels of performance. An interface asic for mems vibratory gyroscopes with. This is accomplished by an electronic feedback system which. The sensing element in the bar type is formed by several vibrating objects similar to the bars of a tuning fork. A unique balance between theory and practical design issues. Analysis and design of a 3rd order velocitycontrolled. This understanding is essential for realization of micro electro. Memsbased gyroscopes vibrating ring gyroscope najafi, michigan laser polarizer rbxe cell 3.
Micro machined gyroscopes use vibrating mechanical elements proofmass to sense rotation. Vibratory gyroscope article about vibratory gyroscope by. Mems, vibratory gyroscope, forcebalancing control, mpc, laguerre functions. Index termsautomotive sensors, inertial sensors, microelec tromechanical systems mems, micromachined gyroscopes. Quadratureinduced noise in coriolis vibratory gyroscopes. Mems vibratory gyroscopes structural approaches to. Out of three mems vibratory gyroscopes tested without insitu device calibration, it was observed that samples had minimum and maximum insitu zero rate output zro drift of 1. One of these gyroscopes is the piezoelectric plate gyroscope which uses a pzt plate as its base. The hf2li offers a variety of features, which makes it a powerful instrument for driving and characterizing vibratory gyroscopes, accelerometers and other mems oscillating structures. The preferable mems implementation of type i gyroscope is an isotropic. Pdf modeling and simulation of the mems vibratory gyroscope. Dreyer department of mechanicalandmechatronic engineering, university ofstellenbosch, private bag x1,7602matieland,southafrica thesis.
They have no rotating parts that require bearings, and hence they can be easily miniaturized and batch fabricated using micromachining techniques. Vibratory gyroscopes cvg is an ongoing research topic. Analysis and design of a 3rd order velocitycontrolled closed. Ece, tongji university, shanghai, china, june, 2005 042009 thesis advisor. Mems vibratory gyroscopes request pdf researchgate. Theory and design of micromechanical vibratory gyroscopes, 2006. In the first part, the dynamics of the vibratory gyroscope sensing. Mems vibratory gyroscopes provides a solid foundation in the theory and fundamental operational principles of micromachined vibratory rate gyroscopes, and introduces structural designs that provide inherent robustness against structural and environmental variations. Development of a lateral velocitycontrolled mems vibratory.
Mems vibratory gyroscope graduation project thesis 1 faculty of engineering ain shams university in partial fulfillment of the requirements for the degree bachelor of science in communication systems engineering submitted byabdel rahman elnaggar, ahmed magdy, ahmed m. Transient response and stability of the agcpi closedloop controlled mems vibratory gyroscopes j cui, x z chi, h t ding et al. This paper presents a novel adaptive approach that can identify, in an online fashion, angular rate and other system parameters. There are bar and rotor types of vibratory gyroscope. Although all vibratory mems gyroscopes rely on the rotationinduced coriolis force, the operating modes of the two technologies are different. This paper presents a detailed model for possible vibration effects on mems degenerate gyroscopes represented by vibratory ring gyroscopes. Design and simulation of mems comb vibratory gyroscope. When we rotated, the coriolis force creates an orthogonal vibration that can be sensed by a variation of devices. Kane, general physics discuss angular motion, moments of inertia, simple harmonic motion, etc. While vibrating ring gyroscopes and tuning fork gyroscopes were the first successful mems gyroscopes and are still the most widely produced, other successful mems gyroscopes have since been created. The vibrating ring gyroscope is immune to the spurious vibration and temperature. Most of the mems gyroscopes are of vibratory kind gyroscopes, i.
Evaluating error sources during mems gyroscope selection. Basic vibratory gyroscope operation vibratory gyroscope. Mems vibratory gyroscopes provides a solid foundation in the theory and fundamental. These gyroscopes use electrostatic comb drive to activate the device in x. The tuning fork gyroscopes have a pair of masses that are motivated to fluctuate with equal amplitude but in reverse directions. Mems vibratory gyroscopes, because of their high quality factor qfactor, are known to be susceptible to vibration. The underlying physical principle is that a vibrating object. A simplified model of vibratory gyros is shown in figure 1. Overview a tuning fork mems gyroscope is designed with a perforated proof mass. Nov 20, 2010 mems gyroscopes include a mechanical resonator supporting two resonating modes, the primary mode and the secondary mode. The perforation enables the release of the proof mass during etching process in the fabrication.
The proposed approach develops an online identifier scheme, by rewriting the dynamic model of mems gyroscope. A mems gyro scope is a micromachined inertial device that can measure the angle of orientation or the angular rate of rotation. A novel method for finding the best excitation frequency. Theory and design of micromechanical vibratory gyroscopes 175 oscillatory continuous discrete multiple single hrg ring tuning fork single mass beam gimballed wheel rotary dtg figure 2. Feng and fan 10 presented an adaptive estimatorbased technique to estimate the angular motion by providing the coriolis force as the input to the adaptive estimator and to improve the bandwidth of. Among various mems sensors, a rate gyroscope is one of the most complex sensors from the design point of view.
Simulations and measurements proving the feasibility of the proposed concepts. The gyroscope a large acquaintance with particulars often makes us wiser than the possession of abstract formulas, however deep. Microelectromechanical systems mems vibratory gyroscopes are among the most commercialized mems products. A mems gyroscope is a micromachined inertial device that can be used to measure the angular rate of rotation or the angle of orientation. Mscengmech march2008 this thesis aims to contribute to themodellingand analysisofmems gyroscope technologies. In microelectromechanical vibratory gyroscopes, feedback control is a common strategy in attempting to correct the imperfections. Theory and design of micromechanical vibratory gyroscopes. In the first part, the dynamics of the vibratory gyroscope sensing element is developed, common microfabrication processes and. Despite diverse designs of mems gyroscopes based on variant principles, vibratory rate gyroscopes are the most investigated 9. A bartype vibratory gyroscope now in practical use is the socalled girotron see figure 1.
System identification of mems vibratory gyroscope sensor. Us6046531a us09108,500 us10850098a us6046531a us 6046531 a us6046531 a us 6046531a us 10850098 a us10850098 a us 10850098a us 6046531 a us6046531 a us 6046531a authority us united states prior art keywords vibration bending leg vibrator base part prior art date 19970704 legal status the legal status is an assumption and is not a legal conclusion. Boser, chair inexpensive mems gyroscopes are enabling a wide range of automotive and consumer applications. The normal gyroscope shown in fig1 is using the comb type structures to drive the tuningfork into. Mems vibratory gyroscopes structural approaches to improve robustness. Model predictive control of mems vibratory gyroscope. Modelling of mems vibratory gyroscopes utilizing phase. The high q is beneficial in improving gyro performance but also amplifies vibration amplitudes at certain frequencies and increases output signal distortions. They represent an important inertial technology because other gyroscopes such as solidstate gyroscopes, laser ring gyroscopes and fibre optic. Therefore the acceleration terms are assumed to be compensated by signal processing and will be neglected.