CN114858151A

CN114858151A - Micro-nano structure for shaking of MEMS gyroscope

Info

Publication number: CN114858151A
Application number: CN202210792146.9A
Authority: CN
Inventors: 郭芃; 李长健; 冯立辉; 郭军强
Original assignee: Beijing Institute of Technology BIT
Current assignee: Beijing Institute of Technology BIT
Priority date: 2022-07-07
Filing date: 2022-07-07
Publication date: 2022-08-05
Anticipated expiration: 2042-07-07
Also published as: CN114858151B

Abstract

The invention discloses a shaking micro-nano structure of an MEMS gyroscope, which comprises a support column, an outer ring, a folding beam and an electrode, wherein the support column is arranged on the outer ring; the support column and the outer lane are coaxial to be set up, and folding beam is used for radially setting up a plurality of folding beams between support column and outer lane and at 360 degrees within ranges evenly distributed of circumference, sets up positive negative electrode in folding beam's side, and folding beam has bilateral symmetry's beta structure, beta structure has increased the surface area of positive negative electrode. The shaking micro-nano structure adopts a folding beam structure to increase the surface area of an electrode, so that the driving voltage is lower under the condition of the same shaking amplitude; the outer ring of the jitter micro-nano structure is of a hollow structure, so that a larger jitter amplitude is realized. The gyroscope has the advantages of low cost, small volume, simple structure, low driving voltage and high dithering frequency, and can shorten the starting time and improve the response speed when being used for the gyroscope of the inertial navigation system.

Description

Micro-nano structure for shaking of MEMS gyroscope

Technical Field

The technical field of MEMS and inertial navigation, and relates to a shaking micro-nano structure of an MEMS gyroscope.

Background

The gyro zero offset is a main error source influencing the precision of the inertial navigation system, and the index of the inertial navigation system can be ensured only by periodically calibrating and detecting the gyro zero offset installed with the system. With the increase of the number of the inertial navigation systems in the application equipment, the periodic calibration and detection of the inertial navigation system bring heavier and heavier burden to the user, and the user urgently needs to realize that the inertial navigation system is free from calibration. How to reduce or even eliminate zero offset is always a technical challenge and difficulty faced by the research of gyro technology, and is also a precondition for realizing calibration-free of an inertial navigation system.

At present, the static performance (zero-bias stability and resolution) of the conventional MEMS gyroscope can meet most application requirements. However, the zero offset is affected by temperature, mechanical environment, packaging stress, packaging gas and the like, and particularly, after the MEMS gyroscope is stored for a long time, the problem that the actual measurement drifts along with the time still exists.

In order to solve the above problems, the prior art has a method for eliminating the zero offset of the gyro by modulation and demodulation. The method carries out periodic modulation on the gyroscope sensitive shaft, modulates the gyroscope zero bias to high frequency in the process of demodulating the angular speed, and eliminates the gyroscope zero bias through filtering. However, the existing jitter modulation mechanism generally has the defects of complex electromechanical structure and large volume, so that the gyroscope has long starting time, poor dynamic performance and high cost. Therefore, the range of application of the shaking mechanisms is limited, and the shaking mechanisms are not suitable for the MEMS gyroscope of the inertial navigation system needing quick response.

Disclosure of Invention

The invention aims to overcome the defects of high driving voltage, low dithering frequency, insufficient driving efficiency and high cost caused by complex electromechanical structure and large volume of the traditional MEMS gyroscope dithering modulation mechanism. A micro-nano shaking structure of an MEMS gyroscope is provided.

In order to achieve the aim, the invention provides a shaking micro-nano structure of an MEMS gyroscope, which comprises a support column, an outer ring, a folding beam and an electrode, wherein the support column is arranged on the outer ring; during the support column was fixed in the MEMS top, outer lane and the coaxial setting of support column, a plurality of folding beams radially set up between support column and outer lane and at 360 degrees within ranges evenly distributed of circumference, and folding beam includes the multistage monospar and connects the connecting portion of adjacent monospar, and the side of every section monospar all is provided with positive negative electrode, and the multistage monospar passes through connecting portion to be connected the beta structure who forms bilateral symmetry, beta structure is used for increasing the surface area of positive negative electrode.

In accordance with the above aspect and any one of the possible implementations, there is further provided an implementation in which the single beams of the folding beam are rectangular solids, and the multiple sections of the single beams are parallel to each other.

In the above aspect and any possible implementation manner, a section of single beam is disposed on a symmetry axis of the folding beam, n folding structures are disposed on two sides of the symmetry axis respectively, the folding beam is folded 2n times, and n is a natural number.

In the aspect and any possible implementation manner described above, an implementation manner is further provided, in which positive and negative electrodes are arranged only on the left and right sides of the single beam of the folded beam, the left and right sides are arranged in the same manner, the positive and negative electrodes are arranged in a staggered manner in the length direction, and a space is left between the electrodes on the same side and the electrodes on different sides; the electrode distribution rules of the single beams adjacent to the angle are opposite, and the electrode distribution rules of the folding beams adjacent to the angle are opposite.

According to the above aspects and any possible implementation manner, a further implementation manner is provided, in which positive and negative electrodes are arranged on four front, back, left and right sides of a single beam of a folded beam, electrode distribution laws of two parallel surfaces are the same, electrode distribution laws of two orthogonal surfaces are opposite, the four sides are all in a manner that the positive and negative electrodes are arranged in a staggered manner in the length direction, and a gap is reserved between electrodes on the same side and electrodes on different sides; the electrode distribution rules of two single beams adjacent to each other at an angle are opposite; the electrode distribution rules of the folding beams adjacent to each other at the angle are opposite.

The above aspect and any possible implementation further provide an implementation in which the positive electrode applies a periodically varying drive voltage and the negative electrode is grounded.

In accordance with the above aspect and any possible implementation manner, there is further provided an implementation manner in which the cathodes are all connected together and then connected to the outer ring, and grounded through the outer ring.

In accordance with the foregoing aspect and any one of the possible implementations, there is further provided an implementation, in which the outer ring is a hollow structure.

The outer ring comprises an outer ring main body and outer spokes, one end of each outer spoke is connected with the outer ring of the outer ring main body and is uniformly distributed on the circumference, mass blocks are arranged between the outer spokes on one, two or more concentric circumferences outside the outer ring main body, and two ends of each mass block are respectively connected with the adjacent outer spokes through connecting beams, so that a hollow structure of the outer ring is formed, the center of the whole hollow structure is symmetrical, and the center of gravity is located at the center of the outer ring.

In the aspect and any possible implementation manner described above, an implementation manner is further provided, in which the outer ring further includes inner spokes, one end of each inner spoke is connected to the inner ring of the outer ring main body, and the other end of each inner spoke is suspended, and the inner spokes are uniformly arranged between two angularly adjacent folding beams.

Advantageous effects

Compared with the existing dithering micro-nano structure, the dithering micro-nano structure of the MEMS gyroscope has the following beneficial effects:

firstly, the shaking micro-nano structure adopts a folding beam, so that the surface area of an electrode is greatly increased, and the driving voltage is lower under the condition of the same shaking amplitude;

secondly, the outer ring of the jitter micro-nano structure adopts a hollow structure, and the jitter amplitude is larger under the drive of the same voltage;

thirdly, the jitter micro-nano structure adopts the optimized structural design of the folding beam and the hollow outer ring, so that the jitter frequency is increased, the working bandwidth is increased, the zero offset automatic elimination effect of the gyroscope is good, and the application scenes of the MEMS gyroscope are widened;

fourthly, the jitter micro-nano structure is simple to realize and has the advantages of low cost and small size.

Drawings

Fig. 1 is a schematic diagram of a dithering micro-nano structure of an MEMS gyroscope in embodiment 1 of the present invention.

Fig. 2 is a schematic view of a folded beam of the dither micro-nano structure of the MEMS gyroscope in embodiment 1 of the present invention.

Fig. 3 is a schematic diagram of electrode distribution of a dither micro-nano structure of the MEMS gyroscope in embodiment 1 of the present invention.

Fig. 4 is a schematic diagram of an electrode arrangement in embodiment 2 of the present invention.

Fig. 5 is a schematic view of another electrode arrangement in embodiment 2 of the present invention.

Fig. 6 is a schematic diagram of an outer ring hollow structure of a dithering micro-nano structure of an MEMS gyroscope in embodiment 3 of the present invention.

Fig. 7 is a schematic diagram of a first-order mode shape of a dither micro-nano structure of an MEMS gyroscope according to embodiment 5 of the present invention.

Fig. 8 is a frequency response diagram of the dither micro-nano structure of the MEMS gyroscope according to embodiment 5 of the present invention.

Fig. 9 is a simulation parameter diagram of embodiment 5 of the present invention.

Fig. 10 is a frequency response diagram of the dither micro-nano structure of the MEMS gyroscope according to embodiment 5 of the present invention at different r0 times.

Fig. 11 is a frequency response diagram of the dither micro-nano structure of the MEMS gyroscope according to embodiment 5 of the present invention at different h 0.

Fig. 12 is a frequency response diagram of the dither micro-nano structure of the MEMS gyroscope according to embodiment 6 of the present invention at different driving voltages.

Illustration of the drawings:

1-supporting column, 2-folding beam, 3-outer ring, 30-outer ring main body, 31-inner spoke, 32-outer spoke, 33-mass block, 34-connecting beam and 4-circular fixed constraint area; 5-positive electrode; 6-negative pole.

Detailed Description

The method is characterized in that a gyroscope sensitive shaft is periodically modulated, the gyroscope is modulated to high frequency in a zero offset mode, and the gyro zero offset is eliminated through filtering in the angular speed demodulation process, so that the basic principle of eliminating the gyro zero error is realized. The method for eliminating gyro zero offset by modulation and demodulation is applied. However, the existing jitter modulation mechanism generally has the defects of complex electromechanical structure and large volume, so that the gyroscope has high driving voltage, long starting time, poor dynamic performance, difficulty in reducing the cost and limited application range. The MEMS gyroscope is not suitable for an inertial navigation system needing quick response.

Therefore, the inventor aims to apply the basic principle of eliminating the zero offset of the gyroscope through modulation and demodulation to the MEMS gyroscope to eliminate the zero offset, realize the jitter micro-nano structure of the MEMS gyroscope with simple electromechanical structure, small volume, low cost, low driving voltage and high jitter frequency, and widen the application range of the MEMS.

The invention belongs to the field of gyroscopes, and is used for periodically modulating a gyroscope sensitive shaft, modulating a gyroscope zero bias to a high frequency, and eliminating the gyroscope zero bias through filtering. The invention relates to a shaking micro-nano structure of an MEMS gyroscope, which comprises a support column, an outer ring, a folding beam and an electrode; during the support column was fixed in the MEMS top, outer lane and the coaxial setting of support column, a plurality of folding beams radially set up between support column and outer lane and at 360 degrees within ranges evenly distributed of circumference, and folding beam includes the multistage monospar and connects the connecting portion of adjacent monospar, and the side of every section monospar all is provided with positive negative electrode, and the multistage monospar passes through connecting portion to be connected the beta structure who forms bilateral symmetry, beta structure is used for increasing the surface area of positive negative electrode.

The folding beam is made of piezoelectric materials, the side faces of the folding beam are plated with positive and negative electrodes, compared with a single beam structure, the folding beam is the same in length size, the surface area for arranging the positive and negative electrodes is increased, the shaking amplitude is the same, the driving voltage required by the reverse piezoelectric action is reduced, or the same driving voltage can generate larger shaking amplitude. And the structural strength of the folding beam is higher than that of a single beam, high-frequency jitter can be realized, higher driving voltage can be adopted during starting, the starting time is shortened, and the response speed is improved.

Furthermore, the outer ring of the shaking micro-nano structure of the MEMS gyroscope is of a hollow structure, so that the weight of the outer ring is reduced, the overall strength of the shaking micro-nano structure is improved, and higher shaking frequency, shorter starting time and higher response speed can be realized.

In order to make the technical solutions of the present application better understood, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

For ease of description, the orientations referred to in this application are defined as follows: the directions of the front, back, up, down, left, right, and the like in the present application are the same as the directions of the front, back, left, right, up, down, and the like in the view direction of fig. 1, and the description is only for convenience of describing the present invention and simplification of the description, and the present invention is not to be construed as being limited thereto.

Example 1

Fig. 1 is a structural diagram of a micro-nano structure of a MEMS gyroscope jitter according to an embodiment of the present invention, where 1 is a supporting pillar, 2 is a folding beam, 3 is an outer ring, and 4 is a circular fixed constraint area.

As shown in fig. 1, the dither micro-nano structure of the MEMS gyroscope according to the embodiment of the present invention includes a support pillar 1, a folding beam 2, an outer ring 3, and an electrode; the supporting shaft 1 and the outer ring 3 are coaxially arranged, the plurality of folding beams 3 are radially arranged between the supporting shaft 1 and the outer ring 3 and are uniformly distributed in the circumferential 360-degree range, each folding beam 2 is provided with a folding structure in bilateral symmetry, and the side surfaces of the folding beams 2 are provided with positive and negative electrodes.

The support column 1 is polygonal in main body, is located at the center of the whole shaking micro-nano structure, is fixed in the MEMS gyroscope and is used for fixing the whole shaking micro-nano structure. The main body of the supporting column 1 adopts a polygon, which is convenient for processing and manufacturing on the one hand, and is convenient for connecting a folding beam on the other hand. The polygon side is equal to or greater than 4. In the embodiment shown in fig. 1, the polygonal body is arranged as a hexagon, and the four corners shown in fig. 1 are optional for adjusting the balance of the center of gravity of the whole structure. The support column 1 can be constrained between the gyro substrate and a sensitive structure (e.g. tuning fork) by a central circular fixed constraint area 4.

The folded beam 2 has a left-right symmetrical folded structure, which increases the surface area of the electrode, so that its driving voltage is lower with the same dither amplitude. The folding beam 2 in one embodiment of the present invention comprises a plurality of parallel single beams 21 and a connecting part 22 for connecting adjacent single beams 21, preferably, the single beams 21 are cuboids. As shown in fig. 2, fig. 2 (a) and 2 (b) are provided with a section of single beam 21 on the symmetry axis, two sides of the symmetry axis are symmetrically provided with 2 sections of

single beam

21 and 4 sections of single beam 21 respectively, fig. 2 (a) forms a structure folded twice on one side, fig. 2 (b) forms a structure folded four times on one side, according to the rule shown in the figure, in other implementations of the present invention, the folding beam 2 can also be folded n times on one side and folded 2n times, where n is a natural number as long as the limitation conditions of space and process are met. 4-20, in the embodiment shown in fig. 1, 6 folding beams 2 can be uniformly arranged between the supporting shaft 1 and the outer ring 3 to ensure uniform vibration of the outer ring. The above description of the symmetric structure of the folding beam of the present invention does not mean that the present invention can only be arranged according to the above-mentioned folding rule, and those skilled in the art can design other folding beams with left-right symmetric structure according to the common knowledge and the inventive idea of the present invention, so as to achieve the purpose of increasing the surface area of the electrode by folding.

Fig. 3 is a positive and negative electrode distribution diagram of the MEMS gyroscope shaking micro-nano structure of the present invention, wherein the solid line area is a positive electrode 5, the dotted line area is a negative electrode 6, the electrode distribution rules of two single beams 21 adjacent to each other at an angle are opposite, and the electrode distribution rules of two adjacent folding beams 2 are opposite.

When the shaking micro-nano structure is used for the MEMS tuning fork gyroscope, the supporting column is constrained between the substrate and the tuning fork; the 6 folding beams are distributed annularly at equal angle intervals and connected to the supporting columns; the outer ring is connected with the support column through a reserved folding beam and is coaxially arranged with the support column; the electrodes are arranged on the side surfaces of the 6 folding beams, and the outer ring connected with one end of each electrode is grounded; in order to make the folding beam generate shaking, the positive pole is applied with a periodically-changed driving voltage, and the negative pole is grounded. In the embodiment, the positive electrodes are all connected together through the gold wires, then a sine driving voltage with unchanged frequency and amplitude is added, and the negative electrodes are all connected together through the gold wires and then grounded. At the moment, the 6 folding beams generate periodic deformation in the same direction due to the inverse piezoelectric effect; the deformation of the folding beam is transmitted to the outer ring to drive the outer ring to generate periodic shaking; the periodic jitter of the outer ring drives the tuning fork arranged on the outer ring to generate periodic jitter; the jitter micro-nano structure of the MEMS gyroscope is used for periodically modulating the sensitive axis of the gyroscope, and the zero offset is used for modulating the jitter frequency.

Example 2

The present embodiment describes the electrodes in the micro-nano structure of the MEMS gyroscope shaking in more detail to illustrate the inventive concept of the present invention, the folding beam of the present invention increases the surface area, and can flexibly set more positive and negative electrodes, so that the surface area of the positive and negative electrodes is increased, and the driving voltage is lower under the same shaking amplitude.

For the MEMS gyroscope micro-nano structure with a small size, the electrodes cannot be laid due to the front and rear side surfaces of the single beam 21 being too narrow, and in this case, the electrode arrangement mode as shown in fig. 4 is adopted. In fig. 4, the black portion is the positive electrode 5, and the shaded portion is the negative electrode 6. In the embodiment shown in fig. 4, the electrodes are only arranged on the left and right side surfaces of the single beam 21, each side surface adopts a positive electrode and a negative electrode which are arranged in a staggered manner in the length direction, a gap is left between the electrodes, and the electrodes on the left and right side surfaces of the single beam 21 are arranged in the same rule. Specifically, the upper half of the left and right sides is provided with a positive electrode 5, the lower half is provided with a negative electrode 6, or the upper half of the left and right sides is provided with a negative electrode 6, the lower half is provided with a positive electrode 5, and in the five single beams 21, the electrode distribution laws of two single beams 21 adjacent to each other in angle in the folding beam 2 are opposite, and the electrode distribution laws of the folding beam 2 adjacent to each other in angle are opposite.

For the MEMS gyroscope shaking micro-nano structure with larger size, an electrode arrangement mode shown in figure 5 is adopted. As shown in the figure, the black part is an anode 5, the shadow part is a cathode 6, positive and negative electrodes are distributed on each of the front, back, left and right sides of the single beam 21, and the electrodes are added compared with the arrangement mode of fig. 4. Specifically, 8 electrodes are arranged on each single beam 21, wherein 4 electrodes are anodes, 4 electrodes are cathodes, the electrode distribution regularity of two single beams 21 adjacent to each other at an angle in the folding beam 2 is opposite, and the electrode distribution regularity of the folding beam 2 adjacent to each other at an angle is opposite. More generally, in other embodiments of the present invention, the electrodes on the single beam 21 may be M electrodes, the polarities of adjacent electrodes are different, M is an integer, and M is greater than or equal to 2. The electrodes are typically arranged in a rectangular configuration for ease of manufacturing.

The mode that the positive and negative electrodes are arranged on the side faces of the single beams in a staggered mode enables each section of single beam to generate S-shaped deformation, the adjacent single beams are just opposite in deformation, and then the outer ring is driven to shake.

Example 3

The outer ring in the MEMS gyroscope shaking micro-nano structure is described in more detail in the embodiment so as to explain the invention idea of the invention, the hollow structure of the outer ring reduces the weight, the shaking amplitude is larger under the same voltage driving, the overall strength of the structure is improved by the hollow structure of the outer ring, and higher shaking frequency, larger shaking amplitude, shorter starting time and faster response speed can be realized.

As shown in fig. 1, the outer ring in an embodiment of the present invention includes an outer ring main body 30, inner spokes 31 and outer spokes 32, the inner spokes 31 are selectively arranged for limiting, one end of each inner spoke 31 is connected to the inner ring of the outer ring main body 30, the other end is suspended, the inner spokes 31 are uniformly arranged between two angularly adjacent folding beams 2, one end of each outer spoke 32 is connected to the outer ring of the outer ring main body 30 and are uniformly distributed on the circumference, mass blocks 33 are arranged between the outer spokes 32 and one or more circumferences outside the outer ring main body 30, two ends of each mass block 33 are respectively connected to the adjacent outer spokes 32 through connecting beams 34, so as to form a hollow structure of the outer ring 3, the whole hollow structure is symmetrical in center, and the center of gravity is located at the center of the outer ring 3. As shown in fig. 6, the shape of the mass block includes rectangle, trapezoid, rectangle with rounded corners, and also includes, but is not limited to, circle, square, ellipse, etc. The number of turns of mass block distribution can also be set more need, general number of turns scope is 1~5, and the quantity of every circle of mass block also can change, and its quantity needs to guarantee the symmetric distribution, and the spoke setting shown in figure 1 selects for the integral multiple of 12. Generally, to facilitate mass placement, the aspect ratio of the slot between the two outer spokes in the hollowed-out structure is greater than 1/3.

Example 4

In this embodiment, the size setting of the MEMS gyroscope shaking micro-nano structure of the present invention is described in more detail, so that those skilled in the art can understand the application range of the present invention, but the application range of the present invention is not limited. The present embodiment adopts the dither micro-nano structure of the MEMS gyroscope of embodiment 1. Wherein, the main body of the support pillar 1 is hexagonal, the thickness range is 37.5 μm to 50 μm, and the maximum radius range is 125 μm to 187.5 μm. The interval range of the single beams 21 in the folding beam 2 is 43.75-56.25 μm. The thickness range of the single beam 21 is 37.5 μm to 50 μm, the length range is 500 μm to 625 μm, and the width range is 5.625 μm to 6.875 μm. The electrode is a rectangular electrode, the length range is 162.5-412.5 μm, and the width range is 25-50 μm. The outer ring is a hollow structure, and has a thickness of 37.5 μm to 50 μm and a difference between inner and outer diameters of 750 μm to 875 μm.

Example 5

The embodiment adopts a simulation result to explain the effect of the MEMS gyroscope shaking micro-nano structure in more detail. The MEMS dithering micro-nano structure adopts the folding beam structure and the hollowed-out outer ring structure, so that the driving voltage required by the dithering of the structure can be effectively reduced, and the requirement of large dithering amplitude can be still met compared with the existing structure under the condition of reducing the driving voltage. Through COMSOL simulation, the jitter angle of the single-beam jitter structure can reach about 10 degrees under the driving voltage of less than 50V, the driving frequency is about 461Hz, and the single-beam jitter structure needs at least 100V voltage when jittering 10 degrees. The MEMS dithering micro-nano structure has the advantages of small volume, low driving voltage and simple structure.

In this embodiment, the material of the jitter micro-nano structure of the MEMS gyroscope is quartz crystal, and 6 folding beams, 1 outer ring, 1 support column, and corresponding electrodes are used. The supporting columns are hexagonal, the thickness of each supporting column is 45 micrometers, the maximum radius of each supporting column is 150 micrometers, the supporting columns are constrained on the substrate, and the constraint radius of the circular fixed constraint area 4 is 18.75 micrometers. The 6 folding beams are annularly distributed on the supporting columns at intervals of 60 degrees, the thickness of each folding beam is 45 micrometers, the width of each folding beam is 6.25 micrometers, and the length of each folding beam is 500-625 micrometers. The positive and negative electrodes are distributed on the sides of the 6 folded beams in the manner shown in fig. 4. The outer ring is connected with the support column into a whole through 6 folding beams and is grounded; the thickness of the outer ring structure is 45 μm, and the difference between the inner diameter and the outer diameter is 837.5 μm. The positive electrodes are all connected together through the gold wires, then a sine driving voltage with invariable frequency and amplitude is added, and the negative electrodes are all connected together through the gold wires and then grounded through the connecting outer ring. The 6 beams can generate periodic deformation in the same direction due to the inverse piezoelectric effect, the deformation of the beams is conducted to the outer ring, so that the outer ring is driven to generate periodic jitter, the periodic jitter of the outer ring can drive the gyroscope mounted on the outer ring to generate high-frequency periodic jitter, and periodic modulation on the gyroscope sensitive shaft is achieved. A voltage of 50V with a frequency of approximately 461Hz is applied to the electrodes distributed on the 6 beams, with a jitter angle of up to approximately 10 °.

Table 1 shows COMSOL simulation results of first order characteristic frequencies of the MEMS jitter micro-nano structure of this embodiment under different constraint radii, and it can be seen that the characteristic frequencies of the structure under different constraint radii are all around 461 Hz.

Fig. 7 shows a first-order characteristic mode shape of the MEMS dither micro-nano structure of this embodiment, where the black region is a position P1 before the folded beam is deformed, and the white region is a position P2 after the folded beam is deformed. It can be seen from the figure that the mode shape of its first order characteristic mode conforms to the modulation requirement.

In this example, we performed COMSOL simulation of the frequency response of the structure with a constraint radius of 18.75 μm and a drive voltage of 50V. Fig. 8 is a frequency response graph of the MEMS jitter micro-nano structure at a constraint radius of 18.75 μm, where the abscissa of the graph is frequency Hz and the ordinate is jitter amplitude (in degrees). In specific implementation, the driving voltage of the structure is 50V; it can be seen from the figure that the jitter angle can reach about 10 ° when the driving frequency is 461.05Hz, 461.07 Hz.

In this embodiment, we also perform frequency response simulation on different electrode distributions under the condition that the constraint radius is determined, so as to discuss the influence of different electrode distributions on the structural frequency response.

As shown in fig. 9, r0 represents the distance from the center of the tip of the electrode near the center O, h0 represents the radial distance of the corresponding two electrodes, i.e., the distance between L1 and L2, and r1 represents the radius of constraint. Fig. 10 is a frequency response graph of the MEMS jitter micro-nano structure at different r0, where the abscissa of the graph is frequency Hz and the ordinate is jitter amplitude (in degrees). We fix the constraint radii r1=18.75 μm, h0=40 μm, and then perform a parametric scan on r 0. It can be seen from the figure that r0 has no influence on the frequency response of the structure, and the jitter angle can reach about 10 degrees.

Fig. 11 is a frequency response diagram of the MEMS jitter micro-nano structure at different h0, where the abscissa of the diagram is frequency Hz and the ordinate is jitter amplitude (in degrees). After obtaining the best r0 through fig. 10, we fix r1=18.75 μm and r0=500 μm, and then perform parameter scanning on h0, and it can be seen from the figure that h0 has substantially no influence on the frequency response of the structure, and the jitter angle can reach about 10 °.

Example 6

The present embodiment will explain the effect of the micro-nano structure shown in fig. 5 in more detail by using simulation results. The micro-nano structure of the wheel shaker of the present embodiment is completely the same as that of embodiment 5, but the size is larger, wherein the arrangement of the electrodes with the fixed constraint radius r1=1.50E-4 (m), r0=0.004 (m), and h0=0.0004 (m) adopts the distribution mode shown in fig. 5, and the obtained simulation result is:

fig. 12 is a frequency response diagram of the micro-nano structure of the MEMS gyroscope according to the present embodiment under different driving voltages, where the abscissa of the diagram is frequency Hz and the ordinate of the diagram is the dither amplitude (in degrees). It can be seen from the figure that with the electrode arrangement shown in fig. 5, a dither with an amplitude of about 12 ° can be achieved with a drive voltage of 8V, and a dither with an amplitude of about 14 ° can be achieved with a drive voltage of 10V.

In summary, the dithering micro-nano structure of the MEMS gyroscope of the present invention has the following advantages: firstly, the shaking micro-nano structure adopts a folding beam, so that the surface area of an electrode is greatly increased, and the driving voltage is lower under the condition of the same shaking amplitude; secondly, the outer ring of the jitter micro-nano structure adopts a hollow structure, and the jitter amplitude is larger under the drive of the same voltage; thirdly, the jitter micro-nano structure adopts the optimized structural design of the folding beam and the hollow outer ring, so that the jitter frequency is increased, the working bandwidth is increased, the zero offset automatic elimination effect of the gyroscope is good, and the application scenes of the MEMS gyroscope are widened; fourthly, the jitter micro-nano structure is simple to realize and has the advantages of low cost and small size.

The above description is only an embodiment of the present invention, and is not limited to the disclosure of the embodiment and the drawings. The description of the implementation is only intended to help understand the method of the invention and its core ideas; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and the content of the present specification should not be construed as a limitation to the present invention. Various obvious modifications to it without departing from the spirit of the process of the invention and the scope of the claims are within the scope of protection of the invention.

Claims

1. A shaking micro-nano structure of an MEMS gyroscope comprises a support column, an outer ring, a folding beam and an electrode; during the support column was fixed in the MEMS top, outer lane and the coaxial setting of support column, a plurality of folding beams radially set up between support column and outer lane and at 360 degrees within ranges evenly distributed of circumference, and folding beam includes the multistage monospar and connects the connecting portion of adjacent monospar, and the side of every section monospar all is provided with positive negative electrode, and the multistage monospar passes through connecting portion to be connected the beta structure who forms bilateral symmetry, beta structure is used for increasing the surface area of positive negative electrode.

2. A dither micro-nano structure as claimed in claim 1, wherein the mono-beams of the folded beams are cuboids and the multi-segment mono-beams are parallel to each other.

3. A dither micro-nano structure according to claim 2, wherein a section of single beam is arranged on a symmetry axis of the folding beam, n folding structures are respectively arranged on two sides of the symmetry axis, the folding beam is folded for 2n times, and n is a natural number.

4. The dithering micro-nano structure of claim 3, wherein the single beam of the folded beam is only provided with positive and negative electrodes on the left and right sides, the electrodes are arranged on the left and right sides in the same way, the positive and negative electrodes are arranged in a staggered way in the length direction, and a space is reserved between the electrodes on the same side and different sides; the electrode distribution rules of the single beams adjacent to the angle are opposite, and the electrode distribution rules of the folding beams adjacent to the angle are opposite.

5. A dithering micro-nano structure according to claim 3, wherein,

positive and negative electrodes are arranged on the front, rear, left and right sides of a single beam of the folding beam, the electrode distribution laws of two parallel surfaces are the same, the electrode distribution laws of two orthogonal surfaces are opposite, the four sides are all in a mode that the positive and negative electrodes are arranged in a staggered mode in the length direction, and a gap is reserved between the electrodes on the same side and the different sides; the electrode distribution rules of two single beams adjacent to each other at an angle are opposite; the electrode distribution rules of the folding beams adjacent to each other at the angle are opposite.

6. A dithering micro-nano structure as recited in any one of claims 1-5, wherein the positive pole is applied with a periodically varying driving voltage and the negative pole is grounded.

7. The dithering micro-nano structure of claim 6, wherein the cathodes are connected with the outer ring after being connected together, and are grounded through the outer ring.

8. The dithering micro-nano structure of claim 1, wherein the outer ring is a hollowed-out structure.

9. The jitter micro-nano structure of claim 8, wherein the outer ring comprises an outer ring main body and outer spokes, one end of each outer spoke is connected with the outer ring of the outer ring main body and is uniformly distributed on the circumference, mass blocks are arranged between one, two or more outer spokes on the concentric circumference outside the outer ring main body, two ends of each mass block are respectively connected with the adjacent outer spokes through connecting beams, so that a hollow structure of the outer ring is formed, the whole hollow structure is centrosymmetric, and the center of gravity is located at the center of the outer ring.

10. The dithering micro-nano structure as recited in claim 9, wherein the outer ring further comprises inner spokes, one end of each inner spoke is connected with the inner ring of the outer ring main body, the other end of each inner spoke is suspended, and the inner spokes are uniformly arranged between two folding beams which are adjacent in angle.