Abstract: Dynamic balancing reduces quadrature bias in microfabricated vibrating instruments such as tuning fork gyros so that a purity of motion is achieved in the absence of any angular rate input. Balancing is achieved by ablating (74) or depositing (72) onto support structure (62) for a tuning fork gyroscope rather than the proof mass (60) itself by melting and moving material on a tuning fork beam (62). Such adjusting is advantageously done during actual operation of the gyro by laser beam application through an encapsulating transparent cover which can be either part of the chip die or an external package.

Abstract: The present invention aims at improving detection sensitivity of an angular rate sensor that uses a tuning fork vibrator composed of mono-quartz piezoelectric material such as crystallized quartz. To achieve this purpose, the present invention includes a tuning fork vibrator (10) having two tuning fork prongs (10a) and (10b), and a tuning fork base (10c), comprised of two vibrators (20) and (30) directly bonded into one piece in an orientation of their thickness in a manner that they are oriented in a direction of crystallographic axis that produces piezoelectric phenomenon of reversed polarity with respect to each other in a lateral direction.

Abstract: A vibrator for a vibratory gyroscope including a base part and at least one bending-vibration piece extending from the base part in a direction crossing the longitudinal direction of the base part and a fixing part for fixing one end of the base part. The base part and bending-vibration piece are formed to extend substantially in a specified plane. At the opposite side to one end of the base part, a projection projecting from the bending-vibration piece is provided, or at least a pair of resonant arms resonating with vibration of the base part, wherein the resonant arms project from the fixing part. With this arrangement, it is possible to detect a turning angular rate with high accuracy.

Abstract: A resonator beam structure that, during vibration of the tines, minimizes coupling of a longitudinal motion of the tines into a support structure to which the resonator beam is attached. The resonator beam includes a pair of tines; a first base region mechanically coupling a first ends of the tines together; a second base region mechanically coupling the second ends of the tines together; a first cutout of a first predetermined geometry at a first predetermined position in a closed interior portion of the first base region; and a second cutout of a second predetermined geometry at a second predetermined position in a closed interior portion of the second base region. The invention includes a method for using finite element analysis to determine an optimum geometry and position of the cutouts.

Abstract: A tuning fork gyroscope typically including at least one proof mass with an upper sense plate disposed above the proof mass and a lower sense plate disposed below the proof mass and means for sensing changes in the nominal gaps between the sense plate and the proof mass and for outputting a signal indicative of the gyroscope angular rate.

Abstract: An angular velocity sensor is provided that includes a frame, an oscillator and torsion bars that connect the oscillator to the frame. The frame, the oscillator and the torsion bar are formed integral with each other by etching a material substrate in the thickness direction of the substrate. The oscillator, configured in the form of an H, includes a support, two first arms and two second arms. These arms extend from the support in an arm-extending direction perpendicular to the thickness direction of the substrate. The oscillator includes a mounting surface that is provided with a piezoelectric driver for generating in-plane oscillation of the oscillator, and with a piezoelectric detector for detecting out-of-plane oscillation of the oscillator.

Abstract: A vibration gyro has a vibrator composed of three tines (first, second, and third tines) which are aligned in a single line at prescribed intervals in one direction on a base and extend in a direction perpendicular to an aligning direction. A central second tine and an adjacent first tine on a left are driven by oscillator. Further, Coriolis force generated on the second tine and the third tine on a right is detected by a detector. In this vibration gyro, the dimensions of the parts are determined so as to cause the third tine to substantially stand still when the first and second tines are driven by the oscillator.

Abstract: The invention provides a capacitive micro sensor that suppresses electric noise generated around the electrodes and enhances the S/N ratio to thereby enhance the detection sensitivity. The gyroscope of the invention includes a tuning fork having three legs, driving electrodes and detecting electrodes provided on two glass substrates, driving field-throughs that supply the driving electrodes with a drive signal, and detecting fields-through that extract a detecting signal from the detecting electrodes. And, a shield member between the detecting and the driving, shield members between the detecting and the detecting, and shield members between the driving and the driving are provided, which makes electrostatic shielding between the adjacent field-throughs of the areas where the driving field-throughs and the detecting field-throughs are arrayed.

Abstract: An integral bimorph angular rate sensor is formed by directly bonding two tuning fork members in the thickness direction to enhance the detecting sensitivity of the angular velocity sensor. The individual tuning fork members are formed from a single crystalline piezoelectric material such as quartz and are bonded in the crystal axis direction as to establish a piezoelectric phenomenon wherein the piezoelectric materials of the bonded tuning fork members have inverse polarities in their width or thickness directions.

Abstract: An object of the present invention is to improve the efficiency of a driving operation of an angular rate sensor employing a tuning fork oscillator made of single crystalline piezoelectric material such as quartz. In order to achieve the object of the present invention, a tuning fork oscillator assembled directly has driver electrodes and detector electrodes provided on a first main surface, a second main surface, an outer surface, and an inner surface of a arm, respectively. The oscillator also has a driver electrode, a monitor electrode, and detector electrodes provided on a first main surface, a second main surface, an inner surface, and an outer surface of the other arm thereof, respectively. A driving voltage is supplied from a driving power source so that the two driver electrodes may be equal in the polarity while the polarity of the driver electrode is opposite to that of the driver electrodes.

Abstract: The present invention aims to improve detection characteristics of an angular velocity sensor using a tuning fork vibrator made of a single crystalline piezoelectric material such as quartz. In order to achieve this object, the present invention directly bonds two vibrators (20) and (30) in the thickness direction for an integral structure so that the vibrators have a crystal axis that generate piezoelectric phenomena in inverse polarities in their width directions. Tuning fork vibrator (10) has two tuning fork arms (10a) and (10b) and tuning fork base (10c). Detection electrodes (6), (7), (5), and (8) are disposed on an inner face and outer face of both tuning fork arms (10a) and (10b). Drive electrodes (1) and (2) are disposed on both tunings fork arms (10a) and (10b) against detection electrodes (5), (6), (7), and (8) for canceling capacitive coupling from a drive section to detecting section.

Abstract: Inertial rate sensor and method in which a drive signal consisting initially of a square wave and thereafter a sine wave is applied to a vibratory rate sensing element, a pickup circuit is coupled to the rate sensing element for providing an output signal corresponding to movement of the rate sensing element, the magnitude of the drive signals is adjusted to set a scale factor which determines the sensitivity to movement of the rate sensing element, and a signal in the drive circuit is monitored to detect a failure.

Abstract: A method for designing double-ended tuning fork (DETF) sensors such that the second-order non-linearity of a first DETF and of a second DETF substantially cancel.

Abstract: A gyroscope of the invention is provided with a tuning fork having three legs and a support, a top side glass substrate and a bottom side glass substrate between which the tuning fork is interposed, driving movable electrodes disposed on the top surface of each leg, driving fixed electrodes disposed on the bottom surface of the top side glass substrate so as to face to the driving movable electrodes, six detection movable electrodes connected to each other in parallel disposed on the top surface of the free end of each leg, and six detection fixed electrodes connected to each other in parallel disposed on the bottom surface of the top side glass substrate so as to face to the detection movable electrodes.

Abstract: A piezoelectric vibration gyroscope is composed of a main body shaped into a rectangular plate and provided with obverse and reverse surfaces functioning as major surfaces, and the first and second groups of three arms projecting from the main body in opposite directions and lying on extensions of the major surfaces. The first group of the three arms is composed of two excitation driving side arms excited in an opposite phase and a nonexcitation driving side arm inserted between the two excitation driving side arms. The second group of the three arms is composed of two vibration detecting side arms vibrating in an opposite phase and a nonvibration detecting side arm inserted between the two vibration detecting side arms. The excitation driving side arms are respectively provided with driving electrodes for exciting a tangential vibration therein. The vibration detecting side arms are respectively provided with detecting electrodes for detecting a vertical vibration.

Abstract: A balanced resonant micro electromechanical system angular rate sensor includes a feedback control loop that generates a null signal to rebalance the sense element to cancel any a Coriolis force induced displacement of the proof mass. The null signal is proportional to the Coriolis force and is used as the sensor output signal. A test signal is injected into the null signal feedback control loop. The resulting sensor output signal is a function of the test signal. If there is no change in the output signal following the injection of the test signal or if the output signal resulting from the test signal exceeds a predetermined threshold, the sensor is defective. Because the test signal is used to cancel the proof mass displacement, the test verifies operation of the sensor element.

Abstract: An apparatus and method, for determining an instrument boresight heading. The apparatus comprises an instrument having a boresight, an elevation positioner for positioning the elevation of the instrument boresight having an elevation axis, an azimuth positioner for positioning the azimuth of the instrument boresight having an azimuth axis and a sensor including a gyro having a sensitive axis. The method comprises recording a first output of a gyro of an azimuth positioner having an instrument boresight azimuth heading in a first position, rotating the azimuth positioner to a second position, recording a second output of the gyro and rotating the azimuth positioner to a third position, recording a third output of the gyro and determining the azimuth heading relative to true north from the first, second and third output.

Abstract: A tuning-fork vibratory gyro has first and second arms and a base integrally connected to the first and second arms. The gyro includes drive electrodes used to generate tuning-fork vibrations due to a piezoelectric transversal effect, and detection electrodes provided on the first and second arms and used to output a detection voltage due to an angular velocity.

Abstract: A digital angular rate and acceleration sensor is constructed with force-sensitive resonators positioned longitudinally on one or both sides of the neutral bending plane of a cantilevered structure. The cantilevered structure has an inertial proof mass at its free end with a periodic velocity applied sideways to the bending plane. Rotation about the longitudinal axis, which produces periodic Coriolis acceleration, as well as inertial acceleration applied perpendicular to the bending plane, generate tensile and compressive forces on the resonators thereby altering the resonant frequencies that are thus a measure of angular rate of rotation and acceleration.

Abstract: A rate of rotation sensor is suggested which is structured out of silicon (silicon compounds or silicon/glass compounds) or other semiconductor materials by means of micromechanical techniques. The rate of rotation sensor has the form of a tuning fork whose prongs are situated in planes in parallel to the surface of the semiconductor wafer. These prongs are exited to carry out vibrations in a plane perpendicular to the wafer plane. By means of a sensor element which registers the torsion of the tuning fork suspension, the angular velocity of a rotation of the sensor about an axis in parallel to the tuning fork suspension is measured.

Abstract: A double-ended tuning fork (DETF) sensor having one or more mass balance tabs for equalizing second-order, K2, non-linearity terms between two DETFs, and methods for manufacturing the same.

Abstract: A tuning-fork type vibration gyro enables to suppress pyroelectric noise caused by temperature change and to obtain sensor output having high signal-to-noise ratio. The tuning-fork type vibration gyro includes a tuning-fork type vibration body having two arms mutually disposed in parallel and a base for commonly supporting one end of the each arm, wherein a longitudinal direction of the two arms is defined as a z-axis and a perpendicular direction thereto is defined as an x-axis; driving electrodes respectively formed on the two arms for generating vibration of the two arms in a direction parallel to the x-axis; detecting electrodes respectively formed on the two arms for detecting electromotive force generated when the tuning-fork type vibration body is rotated around the z-axis; and dummy electrodes formed on the two arms in respective areas different from the driving electrodes and the detecting electrodes.

Abstract: Redundant rate sensor and method in which inertial rate is monitored with a plurality of vibratory sensing elements mounted in a single enclosure, signals from the sensing elements are processed to provide an independent rate output signal for each of the sensing elements, and the independent rate output signals are delivered to a connector which is accessible externally of the enclosure.

Abstract: Disclosed is a piezoelectric gyroscope which presents as a generally elongated tubular shape having inner and outer radially polarized annular region defining surfaces, with an inner electrode on the inner surface, and four outer electrodes present on the outer surface. The four electrodes present on the outer surface are oriented such that each is in a separate quadrant, (as the piezoelectric gyroscope generally longitudinally elongated essentially tubular structure is viewed in cross-section), and ideally at substantially ninety degree intervals on the outer surface. In use the piezoelectric gyroscope system is caused to rotate about an essentially centrally located longitudinally oriented axis while a flex inducing driving voltage is applied across two of the four electrodes, (driving) electrodes, which are oriented at substantially 180 degrees with respect to one another, while an output voltage is sensed across the other two (sensing), electrodes. Also disclosed are a tuning-fork shaped variations.

Abstract: An object of the present invention is to improve the efficiency of a driving operation of an angular rate sensor employing a tuning fork oscillator made of single crystalline piezoelectric material such as quartz.

Abstract: The present invention relates to a system for nulling drive feedthrough error in a sensor having first and second drive electrodes which impart vibratory motion to first and second proof masses in response to first and second opposite phase drive signals, and having first and second capacitances defined between the drive electrodes and their associated proof masses. A mismatch between the first and the second capacitance is measured. Drive feedthrough caused by the measured capacitance mismatch is nulled by adjusting the relative amplitudes of the first and second opposite phase drive signals, whereby the ratio of the amplitudes is proportional to the ratio of the first and second capacitances. A servo loop may adaptively effect the ratio of amplitudes.

Abstract: The invention provides a gyroscope that brings about the miniaturization of a device, improvement of detection sensitivity, and reduction of driving voltage. A gyroscope of the present invention is provided with a tuning fork formed of conductive material having a plurality of legs and a support, a top glass substrate and a bottom glass substrate for holding the tuning fork in-between, a plurality of driving electrodes for driving the plurality of legs in capacitance coupling with the legs, and a plurality of detecting electrodes, each detecting electrode is disposed so as to face to the end face of each leg in the extending direction correspondingly to each leg.

Abstract: An apparatus for determining a rotation rate has an oscillatory body 11 on which a plurality of electromechanical converters A, A′, B, B′, C, C′, D, D′ are mounted. At least a first converter A, A′ is caused to oscillate mechanically by an electric driver signal UF,O generated in a first circuit arrangement 12. Further, at least a second converter D, D′ is caused to oscillate mechanically by an electric damping signal UF, D generated in a second circuit arrangement 13. At least a third converter C, C′ emits an electric sensor damping signal US, D which corresponds to the oscillation of the body 11 in the location where the at least third converter D, D′ is mounted. The damping sensor signal US, D is fed back to the input of the second circuit arrangement 13. A voltage divider 31 is provided, by means of which the signal UF, D generated in the second circuit arrangement 13 can be reduced.

Abstract: An angular rate sensor driving circuit shortens a start-up time without increasing a maximum level of amplification factor of a variable gain amplifier beyond a predetermined degree An output signal of a first amplifier is input to a positive input terminal of a third amplifier, a first resistor is inserted between a negative input terminal of the third amplifier and an output terminal of the third amplifier, a voltage having a potential in the vicinity of ½ of a power supply voltage is impressed on the negative input terminal of the third amplifier through a capacitor, a second resistor and a switch are connected in series between the output terminal of the third amplifier and an input terminal of a second amplifier, and the switch is activated by an output of a level judgement circuit.

Abstract: A driving signal is provided to six electrodes (driving electrodes) on one of the surfaces of each of three vibration legs of a three-pronged tuning-fork-type piezoelectric oscillator. Two output electrodes from among six electrodes (output electrodes) on the other surface thereof are connected to two current-to-voltage conversion devices, respectively. Since the two output electrodes are imaginarily short-circuited by the current-to-voltage conversion devices, there is no need to provide a ground electrode between the output electrodes. This makes it possible to simplify an electrode manufacturing process.

Abstract: There is provided a double-headed mass sensor (25) in which between a first connecting plate (22A) joined to a first diaphragm (21A) at respective sides and a second connecting plate (22B) joined to a second diaphragm (21B) at respective sides, a first sensing plate (41A), on which a main element (44) is provided on at least one plane surface, is bridged, and a resonating portion comprising the diaphragms (21A), (21B), the connecting plates (22A), (22B), the first sensing plate (41A) and the main element (44) is joined to a sensor substrate (27). Change in the mass of each of the diaphragms (21A), (21B) is measured by measuring change in the resonant frequency of the resonating portion accompanying the change in the mass of the diaphragms (21A), (21B). The mass sensor of the present invention enables the easy and highly accurate measurement of a minute mass of a nanogram order including microorganisms such as bacteria and viruses, chemical substances, and the thickness of vapor-deposited films.

Abstract: An angular rate sensor comprises a determination circuit (30) for inputting an output signal of a full-wave rectifier circuit (22) and an output signal after amplified by a charge amplifier (25), and making a determination of abnormality, and an output clamping circuit (32) activated by an output signal of the determination circuit (30), if it makes a determination of abnormality, for clamping an output signal of a sensor output terminal at a level close to a power supply voltage or a grounding voltage.

Abstract: An angular rate sensor is capable of restraining an output voltage of the sensor from being offset by suppressing a current flowing in and out of a common terminal so as to prevent it from flowing in and out of a side of a reference voltage generator. The angular rate sensor is provided with a buffer between a reference voltage generator and a support pin, which serves as a common terminal for a vibration exciter, a detector for detecting a level of vibrations, and a detector for detecting a Coriolis' force. A current flowing in and out of the support pin is prevented from flowing in and out of a side of the reference voltage generator.

Abstract: The shape of drive electrodes and/or the shape of detection electrodes of a tuning fork type vibration gyro are made asymmetrical between the inside and outside of the arm, and between the surface and reverse face of the arm, to reduce the abnormal vibration and leaking output. The drive electrodes to be provided on the inside parts of the surface and reverse face of the first arm are formed smaller than the drive electrodes to be provided on the outside parts of the surface and reverse face thereof. The length of the detection electrode to be provided on the outside lateral face of the second arm is formed short. The drive electrodes to be provided on the surface and reverse face of the first arm are extended to the base side from the boundary position between the first arm and the base, and the detection electrodes to be provided on the surface and reverse face of the second arm are extended to the base side from the boundary position between the second arm and the base.

Abstract: A gyroscope includes a tuning fork, which includes a plurality of tines formed of a conductive material and a supporting portion; an upper glass substrate and a lower glass substrate which sandwich the tuning fork; drive electrodes which are provided on each of the upper and the lower glass substrates in such a manner that parts of the drive electrodes oppose the tines and the remaining parts protrude from the tines, the drive electrodes being capacitively coupled to the tines and driving the tines in a direction parallel to the substrates; and detection electrodes which are capacitively coupled to the tines, and which detect displacements of the tines in a direction perpendicular to the vibrating direction of the tines.

Abstract: The present invention aims to present an angular velocity sensor having a self diagnosis function.

Abstract: The invention relates to an angular velocity sensor used in posture control of a moving element or navigation system, and is intended to realize higher sensitivity, lower offset, lower offset drift, lower translation acceleration sensitivity, and higher impact resistance in a small size and at low cost.

Abstract: A microfabricated gyroscope to measure rotation about an axis parallel to the surface of the substrate. A voltage differential may be applied between pairs of electrode fingers to reduce the quadrature error. A microfabricated gyroscope includes a vibratory structure and interdigited electrodes having a high aspect ratio.

Abstract: A pair of electrodes are formed on the front surface and the rear surface of each vibrator in a longitudinal direction, and dielectric polarization is performed in the direction from the front surface to the rear surface. When I/V converters constituted by operational amplifiers are connected to electrodes of the middle vibrator, the detection electrodes can be grounded to a reference potential Vref through the imaginary short circuits of the I/V converters, so that a gyroscope can be vibrated without a conventional ground electrode. Therefore, the number of electrodes of the vibrators can be reduced, and an interval size between the drive electrodes or between the detection electrodes can be assured. For this reason, sufficient dielectric polarization can be performed when a high voltage is applied.

Abstract: A method for designing a sensor using a dual double-ended tuning forks which provides composite cancellation of second-order non-linearity terms.

Abstract: A method of improving an output characteristic of an angular rate sensor including, for example, a fork oscillator and an improved structure of an angular rate sensor are provided. The improvement of the output characteristic is achieved by adjusting a physical structure of the oscillator to minimize unwanted vibrations of the oscillator or noises of a sensor output. The adjustment of the physical structure is achieved by trimming away an edge portion of the oscillator or a supporter for supporting the oscillator on a base.

Abstract: The present invention provides a piezo-electric vibration gyroscope comprising: a body of a rectangle plate shape defined by a first size in a length direction and a second size in a width direction; plural driver arms extending from a first side of the body in the length direction and also extending in the same plane as the body; plural detective arms extending from a second side opposite to the first side of the body in an anti-parallel direction to the length direction and also extending in the same plane as the body; plural driver electrodes being provided on the plural driver arms and being applied with an alternating current voltage for causing the plural driver electrodes to show an in-plane vibration of a driving mode in the width direction included in the plane; plural detecting electrodes on at least one of the plural detective arms for detecting a voltage caused by a vertical-to-plane vibration of a detective mode in a vertical direction to the plane, wherein the first size of the body is equal to

Abstract: The invention provides a capacitive micro sensor that suppresses electric noises generated around the electrodes and enhances the S/N ratio to thereby enhance the detection sensitivity. The gyroscope of the invention includes a tuning fork having three legs, driving electrodes and detecting electrodes provided on two glass substrates, driving fields-through that supply the driving electrodes with a drive signal, and detecting fields-through that extract a detecting signal from the detecting electrodes. And, a shield member between the detecting and the driving, shield members between the detecting and the detecting, and shield members between the driving and the driving are provided, which makes electrostatic shielding between the adjacent fields-through of the areas where the driving fields-through and the detecting fields-through are arrayed.

Abstract: A silicon gyroscope comprises a vibrator 1 which is made from a silicon wafer and has three elastic arms 2 separated by two notches, with part of the root section of vibrator which supports the elastic arms being fixed to a base plate 3, horizontal electrodes 4 which are laid between the elastic arms and on the outer sides of the elastic arms by being orthogonal to the plane of layout of the elastic arms and close to the elastic arms, and vertical electrodes 5 which are laid in correspondence to the elastic arms by being parallel to the arm layout plane and close to the elastic arms. The silicon gyroscope which is driven in innovative manner is capable of stably detecting the angular velocity.

Abstract: A micromechanical tuning fork gyroscope has an input axis out of the plane of the structure. In one embodiment, capacitor plates are provided in parallel strips beneath two apertured, planar proof masses suspended from a substrate by a support structure. The proof masses are paired and set in opposed vibrational motion by an electrostatic comb drive. In response to an input angular rate about the out-of-plane input axis, the proof masses translate with respect to the striped capacitors, thereby varying the capacitance between the capacitor strips and the proof masses as a function of the input rate. In another embodiment, proof mass combs of a comb drive are meshed between fixed drive combs which are electrically excited in pairs 180° out of phase.

Abstract: A tuning-fork vibratory gyro has first and second arms and a base integrally connected to the first and second arms. The gyro includes drive electrodes used to generate tuning-fork vibrations due to a piezoelectric transversal effect, and detection electrodes provided on the first and second arms and used to output a detection voltage due to an angular velocity.

Abstract: A vibration gyro sensor is constructed as follows. Namely, a detecting piezoelectric/electrostrictive element 12, which detects displacement generated in a direction perpendicular to a direction of vibration of a vibrator 2 when the vibrator is rotated, is provided on a detecting section. The detecting section is constructed by an integrated fired product made of ceramics together with the vibrator 2 and a support base 4. The detecting section is constructed by a first plate-shaped section 6 which is more thin-walled than the vibrator 2 and which has its principal surface extending in the direction of vibration. The piezoelectric/electrostrictive element 12 is formed in an integrated manner on the first plate-shaped section 6 in accordance with a film formation method.

Abstract: The invention relates to an angular velocity sensor used in posture control of a moving element or navigation system, and is intended to realize higher sensitivity, lower offset, lower offset drift, lower translation acceleration sensitivity, and higher impact resistance in a small size and at low cost.

Abstract: A tuning-fork vibratory gyro has first and second arms and a base integrally connected to the first and second arms. The gyro includes drive electrodes used to generate tuning-fork vibrations due to a piezoelectric transversal effect, and detection electrodes provided on the first and second arms and used to output a detection voltage due to an angular velocity.

Abstract: A method of improving an output characteristic of an angular rate sensor including, for example, a fork oscillator and an improved structure of an angular rate sensor are provided. The improvement of the output characteristic is achieved by adjusting a physical structure of the oscillator to minimize unwanted vibrations of the oscillator or noises of a sensor output. The adjustment of the physical structure is achieved by trimming away an edge portion of the oscillator or a supporter for supporting the oscillator on a base.