UA24037U - Hemi-spherical resonator gyroscope with component resonator - Google Patents

Abstract

Hemi-spherical resonator gyroscope with component resonator has hemi-spherical resonator, circular excitation electrode and numerical capacitor electrodes for support of oscillations of hemi-spherical resonator without taking information placed in nodes and loops of vibrations of hemi-spherical resonator. Hemi-spherical resonator is made without stem and has opening in its pole. Circular excitation electrode is arranged as piezoelectric disc with opening in center and with continuous conducting surface. Hemi-spherical resonator is placed with its pole over conductive surface of piezoelectric disc and is connected to it by means of glue joint.

Description

Description of the invention

This useful model refers to the field of development of gyroscopic devices, in particular - to the technology of 2 Coriolis vibration gyroscopes, namely - to hemispherical gyroscopes with a quartz resonator, and can be used in systems of orientation, navigation and control of moving objects.

Known Coriolis vibrating gyroscopes with legs (US patent Mo5383362, class B0O1R15/08 "Sopigo!Y og mirgaiogu dugozsore", 24.01.1995; US patent Mo4951508, class (301C19/42 "Mirgafgu goiatsyop zepvog", 28.08.1990; patent USA Mo4157041, class 01R9/04 "Bopis mibgayipod bBeiY dugo", 5.06.1979; V.A. Matveev, V.I. Lypatnikov, A.V. 70 dlekhin "Design of a wave solid-state gyroscope", M., Moscow State Technical University publishing house N.Z. Bauman, 1998, pp. 18-21, Fig. 1.12, containing a sensitive element (resonator) with a leg and a ring excitation electrode, while the resonator is made in the form of a hemisphere with strict axial symmetry and is made of either fused quartz glass, or from piezoceramic material, and can also be metal. Fused quartz glass has highly stable elastic characteristics, has a high Q-factor - therefore its use 12 in the manufacture of a resonator is the best compared to the manufacture of a resonator from other materials. The highest measurement accuracy provide gyrosk ops built on the basis of hemispherical quartz resonators: yes, the Q factor of these resonators reaches several million, while metal ones - several tens of thousands.

The closest analogue of the claimed device, chosen as a prototype, is the above-mentioned vibrating gyroscope, described in the US patent Mo49515081I.

A quartz vibrating gyroscope can work as an angular rate sensor in two modes: open-feedback and closed-feedback. In addition, this gyroscope can work in integrating mode. When the gyroscope is operating in the angular velocity sensor mode, the angular velocity of the base on which the gyroscope is mounted is measured (in this case, the positional excitation mode of the resonator is implemented). When the gyroscope is operating in the integrating mode, information on the increase in the angle of rotation 29 of the gyroscope base is recorded (the mode of parametric excitation of the resonator is implemented). in

In the simplest operating mode of the gyroscope (with open feedback), when an alternating signal is applied to the excitation ring electrode, an elastic standing wave occurs on one of the resonator oscillation modes (excited mode), while the second mode with a given amplitude, which stabilizes, is most often used in practice using a system of automatic gain control. A standing wave on the second mode of oscillation is characterized by four antinodes and four oscillation nodes. co

Rotation around the axis of symmetry of the vibrating structure (annular excitation electrode 7 resonator) leads to the Coriolis acceleration acceleration o,: o « ek (ОЧМ), (1) с where 0 is the angular velocity of rotation of the resonator around the axis of symmetry, M is the linear velocity of the structure elements in the process of vibration.

The Coriolis force for the mass dt will be: « s 70 Equator (2) 8 z», while the specific Coriolis force will be:

Ek-2(охУ) (3) ko The action of the Coriolis force causes the appearance of a measured (Coriolis) mode of oscillations, the amplitude of which is proportional to their angular velocity of rotation 0. The measured mode is oriented so that its nodes are located on the bundles of the excited mode, and the waves on the nodes of the excited mode fashion For the second vibration mode, these two modes are spatially rotated ("in") relative to each other by an angle of 459. s 20 When the gyroscope operates in the open feedback mode, its bandwidth depends on the Q factor of the OO of the measured mode, that is, on the decay time of the oscillations of this mode : so, for example, at 2-1000 and "m natural frequency of oscillations of the resonator T5-5000 Hz, the bandwidth of M a pov - Such a gyroscope ш-О-- - ХЦ yav can measure only constant angular velocities, for example, horizontal or vertical components of angular s speed of rotation of the Earth.

In order to increase the bandwidth of the gyroscope, it is necessary to ensure the rapid attenuation of the measured oscillation mode, which leads to a decrease in the CO of this mode and, accordingly, to an increase in the bandwidth of the gyroscope. because such damping of the measured oscillation mode occurs when the gyroscope operates in the closed feedback mode, i.e. in the mode of force balancing of the wave. In this mode, the signal of the node of the excited mode is measured (the signal of the measured mode is blown), a negative feedback signal is formed, compensating the signal generated in the node by applying an anti-phase signal to the second of the four nodes, which allows to suppress the measured mode of oscillation, providing a small value of C) (yes, at 0-1, the value of lD-bOHc is reached). 65 When the gyroscope works in the integrating mode, the Coriolis force contributes to the transition of the energy of oscillations of the excited mode into the measured mode and vice versa, while the elastic wave will rotate together with the resonator. The angle of rotation of the elastic wave will lag behind the angle of rotation of the base of the gyroscope relative to the inertial space by the value of a constant coefficient, which is determined only by the operating mode of oscillations (for example, this coefficient is approximately equal to 0.32 for the second mode of oscillations and approximately 0.25 for the third mode of oscillations).

Coriolis vibration gyroscopes with a resonator with a leg, in particular - and the device chosen as a prototype, have the following disadvantages: 1) in a resonator with a leg (or legs), it is made together with a hemisphere from one piece, for example, quartz, which complicates the technology of such implementation , makes it more expensive and makes it unsuitable for mass production of gyroscopes; 70 2) the use of the above-mentioned manufacturing technology does not allow making a high-quality hemisphere: due to the fact that the walls of the hemisphere are of unequal thickness, the problem of unbalancing the masses of the hemisphere along its circular coordinate arises, and this further leads to the need for static and dynamic balancing of the masses of the resonator, which is a complex and expensive procedure using special technologies to remove micromasses from it; 3) to excite such a resonator with the help of electrostatic forces, that is, with the use of capacitive electrodes used in the above-mentioned patents, it is necessary to use high voltages with an amplitude of up to 60Ω0V at the natural frequency of oscillations of the resonator, and to support them, it is necessary to use voltages of up to 60V, which is provided by a special excitation circuit with high power consumption.

The listed disadvantages are inherent in all designs of such gyroscopes, both with open feedback and with closed feedback, and especially when the gyroscope is operating in integrating mode.

The useful model is based on the task of improving the device by making a hemispherical resonator without a leg and connecting it to a ring electrode of excitation with the help of glue, and this electrode is made solid with the possibility of using the third mode of oscillations of the resonator with a given amplitude.

The problem is solved in such a way that in a hemispherical resonator gyroscope with a composite resonator containing a hemispherical resonator, an excitation ring electrode and a set of capacitive electrodes for maintaining the oscillations of the hemispherical resonator and removing information located in the nodes and bundles of the hemispherical resonator oscillations, the new thing is that in it the hemispherical resonator is made without a leg and is provided with a hole in its pole, the excitation ring electrode is made in the form of a piezoelectric disk with a hole in the center and with a continuous conductive surface for applying an alternating voltage to it with the possibility of exciting the oscillations of the resonator, while the hemispherical resonator is placed with its pole above the conductive surface of the piezoelectric disk and is connected to it by means of an adhesive connection with the possibility of eliminating energy losses of the resonator, and the round hole of the hemispherical resonator is located above the round hole of the piezoelectric disk, while radius of its hole co falls with the radius of the opening of the hemispherical resonator. -

The proposed design of the gyroscope using a hemispherical resonator without a leg allows you to significantly improve the quality of the resonator, reduce the thickness of the surface of the hemisphere by several times, which ultimately increases the accuracy and sensitivity of the gyroscope. In addition, it becomes possible to use widely known mass production technologies, for example, quartz lenses, which reduces the cost of resonator manufacturing, and also eliminates the need for mechanical (static and "dynamic) balancing of masses. It should be noted that in order to excite the oscillations of the resonator and maintain them with the use of the proposed piezoelectric disc, a voltage of no more than 18 is required, while the power spent on the excitation of the resonator oscillations is equal to hundredths of a microwatt, which is due to the value of the active resistance of the piezoelectric disc, equal to several tens of Mohm.

The essence of a useful model is explained by the following drawings: Fig. 1 shows the third mode of oscillation of a hemispherical quartz resonator with the arrangement of electrodes in

GI nodes and amplitudes of its oscillations, Fig. 2 shows a general view of a sensitive element consisting of a hemispherical quartz resonator connected to a piezoelectric disk, and a scheme for excitation and control of a standing wave, as well as the removal of a signal about the angular velocity in in the case of using a piezoelectric disk with a continuous conductive surface, Fig. 3 shows the nature of oscillations (deformation) of the piezoelectric disk when a periodic voltage "M" is applied to it, Fig. A4 shows the dependence of the amplitude of oscillations at the equator of a hemispherical quartz resonator on the amplitude voltage applied to the piezoelectric disc, Fig. 5 shows graphs of the amplitude-frequency and phase-frequency characteristics of a hemispherical quartz resonator glued to a piezoelectric disc, and Fig. b6 shows a photo of a hemispherical quartz resonator glued to a piezoelectric disc disc

A hemispherical resonator gyroscope with a composite resonator (Fig. 2) consists of a hemispherical resonator 1 with a hole 2 along its pole and a piezoelectric disk Z with a diameter of 2K with a hole 4 with a diameter of 2, a hole made in the center of the disk 3. The resonator 1 is attached to the disk Z by using an adhesive joint in such a way that the pole of the hemisphere 1, i.e. its center, is located in the center of the hole 4 of the disk 3. The disk C is made with a solid conductive surface for supplying current to it (coating - camel or silver) to excite the selected mode of oscillation of the resonator . To excite the resonator in the operating mode, electrodes are used, made by sputtering on the surface of the disk From a metal film. Disk C can be made of any material that has a piezo effect, in particular, of piezoceramic material or fused quartz glass.

When using a disc with a continuous conductive surface, a voltage is applied to it, which provides a parametric excitation mode, and to maintain the oscillations of the resonator and capture the measured signal, capacitive sensors are used, which are installed on the rim of the hemispherical resonator in the nodes and bundles of its oscillations.

A distinctive feature of this design is that the hemispherical resonator 1 vibrates in the third vibration mode.

The advantages of the third mode of oscillations compared to the second mode of oscillations are explained as follows: 1) when the resonator 1 and disk 3 are glued together, vibrating in the second mode of oscillations, this connection turns into a dissipative (non-conservative) system characterized by a significant dissipation of vibration energy, which leads to a loss of the Q-factor of the resonator, and therefore to a decrease in the accuracy of the gyroscope as a whole, and when the third mode of 7/0 Oscillations is excited, the interaction between the resonator 1 and the disk Z will be conservative in nature, as a result of which energy losses will be insignificant (yes, the Q-factor of the resonator with the proposed method of its excitation on the second mode of oscillations is 102, and on the third mode of oscillations the Q-factor reaches the value C 105; 2) on the third mode of oscillations, technological defects in the manufacture of the resonator (different wall thickness, ellipticity) have less effect on the zero drift of the gyroscope.

Based on these considerations, we will consider the third mode of oscillations in the future. The deformation of resonator 1 during oscillations in the third mode is shown in Fig. 1, while the standing wave formed during oscillations will have six antinodes located along axes 1-1", 3-3", 5-5 and six nodes of oscillations located along axes 2-2,4-4,6-6.

The process of excitation of the resonator 1 by the piezoelectric disk C consists in the fact that under the action of an alternating voltage, the disk

C creates a uniformly distributed load along its inner border, the value of which is determined (Fig. 2):

And E ne p sgu z o de dziai, Ed - respectively, the piezoelectric modulus and the Young's modulus of the disc material, Kor - the average radius of the disc, Пп - its average thickness, hо - the inner radius of the disc, о(6) - the amplitude of its radial deformation , 9 - coordinate along the generating hemisphere, 0 - applied voltage. The component of the force acting normal to the surface of the hemisphere (Fig. 2) can be represented as ) o o E o « where K is the radius of the hemisphere, g-gozo(8).

З Decomposition of this force in a series by degrees of small displacements oo with accuracy to the values of the first order of smallness gives the value of the village vt yh 1 s yh - t 0 v s 0;" " where g a ; 8 in the area of contact with the piezoelectric disk can be shi) oyu 8 --- Kpsosa p 2 2 ime) I What is given as Roz p-Z - the mode number of oscillations, du amplitude of deformations t. Ta -sh ш ши о шчи9) -regarding (p и-я 0 2 s 50 s. of the resonator in the region of its equator. "I Equation of the forced motion of the resonator 1, which rotates in its plane with an angular velocity c around the axis of symmetry and which is subjected to the action of an external distributed load, will be written in the partial derivatives for the variable o: " " " (| (- ; (7) с Б - incl rudder ko) as "zv a v )- v gosipy where, 2 EI E - Young's modulus of the resonator material, | - the moment of inertia of the resonator relative to the o-axis Ki is the symmetry of the Z - its cross-sectional area, p - the density of the resonator material, - - the coefficient characterizing the energy loss in the resonator, i.e. its Q factor, Po - the reduced force applied to the resonator, the parameter y - the frequency of the excitation voltage, because Equation (7) is written for the conditions of supplying the piezoelectric disk with an alternating voltage with a frequency close to its own th frequency of the working (third) oscillation mode of the O-Oosovui resonator.

The value of Ro will be written: ? agro p

Ro - kre pz) 70 where p-3, Od - the amplitude of the excitation voltage.

If resonator 1 is not deformed, then the distributed load is balanced by its internal stress. Under the action of force Po, resonator 1 begins to deform, and its deformations are characterized by a specific form (mode) of bending vibrations. At the same time, the distributed force acts more strongly at the points of maximum displacement of the deformed resonator 1 than at the points of minimum displacement. The allowed 7/5 amplitude of deformation odah(9) is determined by the stiffness (elasticity) of the attachment of the hemispherical resonator 1 to the piezoelectric disk 3, namely, the elasticity of the adhesive joint. In the proposed design of the gyroscope, the third mode of oscillations of the resonator 1, as already mentioned, is the best, since it determines the conservative nature of the interaction of the resonator 1 with the piezoelectric disk Z (in the places where the resonator 1 is attached to the piezoelectric disk Z, the amplitude of deformations according to the second form of oscillations on an order of magnitude more than a third, and

This determines the nature of the interaction between resonator 1 and disk Z - dissipative or conservative).

Consideration of the conditions for the existence of limited oscillations of resonator 1 according to equation (7) allows finding the minimum value of the output voltage Oodmip and its dependence on the parameters of the sensitive element, while exceeding the value of this voltage provides stable excitation of the resonator from the condition Eo»r, where 1881 is the decrement and Brchvi - about damping of resonator oscillations.

Therefore, (5) is a sumptuous Sh o body

BA Komepiv) about "

Where из Епыс Н is the coefficient of electromechanical transformation of the piezoelectric disk, кзм- 1 Рсч г - юю чу Вп (пн) ж З с Thus, the noise level of the excitation curve is determined by the energy losses in the resonator 1( 5), its :z » parameters (radius K, moment of inertia I) and depends on the parameters of the piezoelectric disk Z (Kam).

Consider the operation of the piezoelectric disk C in the proposed design of the gyroscope. 415 When using this piezoelectric disk From standing wave control and recording measured

HF signals are carried out using capacitive electrodes, as shown in Fig.2 and described in the above-mentioned patents. The hemispherical resonator 1 is attached to the piezoelectric disk 3, made so that the radius of its inner hole coincides with the radius of the hole in the pole of the hemisphere 1. Excitation of this piezoelectric disk o Z is ensured by applying to it a voltage O-W o vipui, at the same time, disk Z is deformed and, as described in 5p above, the Eosipui force acts on resonator 1, causing oscillations along the third mode. In this case, signals and standing wave control are applied to capacitive electrodes 2, 4, b, and measurement signals "M" are taken from electrodes 2, 4, 6. The nature of the deformation when using disk C is shown in Fig. 3.

The advantage of the proposed technical solution lies in the fact that in the case of imperfect manufacturing of the resonator 1, energy losses through its pole and the adhesive connection of the piezoelectric disk C with the resonator 1 are eliminated, since the amplitude of its oscillations increases with the increase in the imbalance of its masses. In addition, in the proposed design of the quartz hemispherical resonator 1, for the excitation of its oscillations and their support, it is sufficient to use a voltage that does not exceed 18V (Fig. 4), which is associated with the piezoelectric properties of the material of the disk 3, while in the design of the gyroscope chosen as a prototype, as already mentioned, an electrostatic field is used for the same purposes, which requires a voltage of 6О0ОВ for the excitation of oscillations, and 608 for their maintenance.

Fig. 5 shows the amplitude-astotic and phase-frequency characteristics of the proposed hemispherical resonator 1, which is fixed on the disk C by means of an adhesive connection: here - the ratio

Mn

Mgpyach of the measured voltage to the maximum voltage, which is realized at the resonance frequency. The Q-factor of the third vibration mode for this resonator is 1.2.105. and the natural frequency of the third vibration mode is equal to 13760.7 Hz.

A photo of a hemispherical quartz resonator 1 installed on a disk C using an adhesive joint is shown in Fig. b: in this design, the diameter of the quartz hemisphere 1 is 3 mm, and the diameter of the disk C is 20 mm, the diameter of the hole on the disk C and the diameter of the hole in the poles of resonator 1 are equal to 4 mm.

Claims (2)

Formula of the invention 76 1. A hemispherical resonator gyroscope with a composite resonator, containing a hemispherical resonator, an excitation ring electrode and a set of capacitive electrodes for supporting the oscillations of the hemispherical resonator and removing information located in the nodes and bundles of oscillations of the hemispherical resonator, which is distinguished by the fact that it has a hemispherical the resonator is made without a leg and contains a hole in its pole, the ring excitation electrode is made in the form of a piezoelectric disc with a hole in the center and with a continuous conductive surface /5 for applying an alternating voltage to it with the possibility of exciting the oscillations of the resonator, while the hemispherical resonator is placed on its own pole above the conductive surface of the piezoelectric disk and connected to it by means of an adhesive connection with the possibility of eliminating energy losses of the resonator. 2. A hemispherical resonator gyroscope with a composite resonator according to claim 1, which is characterized by the fact that the round hole of the hemispherical resonator is located above the round hole of the piezoelectric disk, and the 2o radius of its hole coincides with the radius of the hole of the hemispherical resonator. z o u (ze) "c) " p - I.Y and? name) sh" ("c) (95) that 60 b5