CN114646309A

CN114646309A - Three-axis gyroscope

Info

Publication number: CN114646309A
Application number: CN202210539045.0A
Authority: CN
Inventors: 黄占喜; 周宁宁; 刘爽; 曲鹏; 黄克刚
Original assignee: Shaoxing Yuanfang Semiconductor Co Ltd
Current assignee: Shaoxing Yuanfang Semiconductor Co Ltd
Priority date: 2022-05-18
Filing date: 2022-05-18
Publication date: 2022-06-21
Anticipated expiration: 2042-05-18
Also published as: CN114646309B

Abstract

The application discloses a triaxial gyroscope, which comprises a substrate, a first X/Z axis detection mass block, a second X/Z axis detection mass block, a first driving mass block and a second driving mass block; the Y-axis detection mass block comprises a first hollow part; the first driving mass block, the first X/Z axis detection mass block, the second X/Z axis detection mass block and the second driving mass block are sequentially arranged along the X direction, are elastically connected and are positioned in the first hollow part; the Y-axis detection mass block is respectively elastically connected with the first driving mass block and the second driving mass block in the X direction; the first X/Z axis detection mass block and the second X/Z axis detection mass block perform resonant motion in opposite directions along the Y direction and are used for detecting angular velocities around the X axis and around the Z axis; the Y-axis detection mass performs reciprocating rotary motion in the XY plane for detecting angular velocity about the Y axis. The angular velocity detection method and device for the three-axis shaft has the advantages that the angular velocity of the three-axis shaft is independently detected, the detection result is accurate, and the reliability is better.

Description

Three-axis gyroscope

Technical Field

The application relates to the technical field of micro electro mechanical systems, in particular to a three-axis gyroscope.

Background

The Micro gyroscope manufactured based on Micro-Electro-Mechanical-System (MEMS) is used for measuring a rotation angular velocity, has a plurality of advantages of small volume, low cost, good integration, excellent performance and the like, is widely applied to non-fields of consumer electronics, industry, medical treatment, military and the like, and is also in standard configuration in the application of consumer electronic products such as various mobile terminals, cameras, game consoles, navigators and the like at present.

The existing three-axis gyroscope usually has two-axis or three-axis tests which are not independent, wherein the motion of one axis interferes the detection result of the other axis, so that the detection result is inaccurate.

Disclosure of Invention

The embodiment of the application provides a triaxial gyroscope which can improve the accuracy of angular velocity detection.

The embodiment of the application provides a three-axis gyroscope which comprises a substrate, a Y-axis detection mass block, two X/Z-axis detection mass blocks and two driving mass blocks, wherein the Y-axis detection mass block, the two X/Z-axis detection mass blocks and the two driving mass blocks are arranged above the substrate in parallel; the two X/Z-axis detection mass blocks are respectively a first X/Z-axis detection mass block and a second X/Z-axis detection mass block, and the two driving mass blocks are respectively a first driving mass block and a second driving mass block;

the Y-axis detection mass block comprises a first hollow part;

the first driving mass block, the first X/Z-axis detection mass block, the second X/Z-axis detection mass block and the second driving mass block are sequentially arranged and elastically connected along the X direction and are positioned in the first hollow part; the Y-axis detection mass block is respectively and elastically connected with the first driving mass block and the second driving mass block in the X direction;

in a detection driving state, the first driving mass block and the second driving mass block are driven to perform resonant motion in opposite directions along the Y direction; the first X/Z-axis detection mass block and the second X/Z-axis detection mass block respectively perform resonant motion in opposite directions along the Y direction under the driving of the first driving mass block and the second driving mass block, and are used for detecting angular velocities around the X axis and the Z axis; the Y-axis detection mass block is driven by the first driving mass block and the second driving mass block to do reciprocating rotation motion in an XY plane and is used for detecting the angular speed around the Y axis.

Optionally, an X-axis electrode and two Z-axis electrodes arranged along the X direction are simultaneously disposed on a region of the substrate corresponding to each X/Z-axis detection mass block;

the X/Z-axis detection mass block is provided with a second hollow part, the two Z-axis electrodes respectively extend into the second hollow part and respectively form a Z-axis detection capacitor with the X/Z-axis detection mass block for detecting the angular speed around the Z axis;

the X-axis electrode and the X/Z-axis detection mass block are arranged oppositely to form an X-axis detection capacitor for detecting the angular velocity around the X axis.

Optionally, the two side walls surrounding the second hollow portion and arranged along the X direction respectively form the Z-axis detection capacitor with the two Z-axis electrodes.

Optionally, a first partition plate is arranged in the second hollow-out portion to partition the second hollow-out portion into two sub-areas arranged along the X direction;

the two Z-axis electrodes extend into the two sub-areas respectively and are opposite to two side faces of the first isolation plate respectively to form two Z-axis detection capacitors.

Optionally, the driving mass includes a third hollow portion;

the three-axis gyroscope further comprises driving parts corresponding to the two driving mass blocks respectively, and the driving parts are located in the third hollow parts to drive the driving mass blocks to do resonant motion.

Optionally, the driving part comprises two electrostatic comb tooth structures arranged along the Y direction;

the static comb tooth structure comprises a movable comb tooth connected with the driving mass block and two fixed comb teeth respectively connected with the substrate, the movable comb tooth and the two fixed comb teeth are arranged along the Y direction, and the two fixed comb teeth are respectively positioned on two sides of the movable comb tooth;

and a driving capacitor is formed between the movable comb teeth and one fixed comb tooth, and a driving detection capacitor is formed between the movable comb teeth and the other fixed comb tooth.

Optionally, the movable comb includes a second isolation plate erected in the X direction on the third hollow portion and connected to the driving mass block, and two lateral surfaces of the second isolation plate are respectively provided with comb teeth arranged in the X direction, wherein a driving capacitor is formed between one lateral surface of the comb tooth and the corresponding fixed comb tooth, and a driving detection capacitor is formed between the other lateral surface of the comb tooth and the corresponding fixed comb tooth.

Optionally, the Y-axis detection mass block includes a first sub mass block, a second sub mass block, a third sub mass block, and a fourth sub mass block, which are sequentially connected end to form the first hollow portion, wherein the first sub mass block and the third sub mass block are arranged along the X direction, and the second sub mass block and the fourth sub mass block are arranged along the Y direction;

the first driving mass block is elastically connected to the inner side surface of the first sub mass block, and the second driving mass block is elastically connected to the inner side surface of the third sub mass block;

and two Y-axis electrodes are arranged on the substrate and are respectively arranged opposite to the second sub mass block and the fourth sub mass block to form a Y-axis detection capacitor for detecting the angular velocity around the Y axis.

Optionally, two ends of the first driving mass in the Y direction and two ends of the second driving mass in the Y direction are respectively connected to the substrate through first elastic members; the first driving mass block and the first X/Z-axis detection mass block, and the second driving mass block and the second X/Z-axis detection mass block are respectively connected through second elastic pieces;

the first driving mass block and the first sub mass block and the second driving mass block and the third sub mass block are respectively connected through third elastic pieces;

and the first X/Z axis detection mass block and the second X/Z axis detection mass block are respectively connected at two ends in the Y direction through fourth elastic pieces.

Optionally, the third elastic member is a first flexible beam;

or the third elastic piece comprises a rectangular frame beam and two second flexible beams which are respectively connected to two opposite sides of the rectangular frame beam;

the rectangular frame beam close to one side of the first sub mass block is respectively connected with the first driving mass block and the first sub mass block through two corresponding second flexible beams;

the rectangular frame beam close to one side of the third sub mass block is respectively connected with the second driving mass block and the third sub mass block through two corresponding second flexible beams;

and/or the fourth elastic part comprises a rigid beam arranged in parallel to the X direction, and a third flexible beam and two fourth flexible beams which are vertically connected to one side of the rigid beam close to the X/Z axis detection mass block, wherein the third flexible beam is positioned between the two fourth flexible beams;

the rigid beam is connected to the substrate through the third flexible beam, connected to the first X/Z axis detection mass block through a fourth flexible beam, and connected to the second X/Z axis detection mass block through another fourth flexible beam.

The three-axis gyroscope has the advantages that the Y-axis detection mass block and the two X/Z-axis detection mass blocks are driven to move through the pair of driving mass blocks, so that the three-axis angular velocities (the angular velocities around the X-axis, the Y-axis and the Z-axis) can be independently detected, mutual interference is avoided, and the detection result is accurate. In addition, the three-axis gyroscope of the application not only uses less mass blocks (only comprises five), but also has the advantages that the two driving mass blocks and the two X/Z axis detection mass blocks are both positioned in the first hollow parts of the Y axis detection mass blocks, the whole structure is compact, the connection is simple, and the reliability is better.

Drawings

The technical solutions and advantages of the present application will become apparent from the following detailed description of specific embodiments of the present application when taken in conjunction with the accompanying drawings.

Fig. 1 is a schematic structural diagram of a three-axis gyroscope according to an embodiment of the present application.

Fig. 2 is an enlarged schematic structural diagram of a portion a in fig. 1 according to an embodiment of the present application.

Fig. 3 is an enlarged schematic structural diagram of a portion a in fig. 1 according to an embodiment of the present application.

Fig. 4 is a schematic structural diagram of a third elastic member according to an embodiment of the present application.

Fig. 5 is a schematic structural diagram of a fourth elastic element according to an embodiment of the present application.

Fig. 6 is an enlarged structural schematic view of the electrostatic comb tooth structure in fig. 1.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

It should be understood that although the terms first, second, third, etc. may be used herein to describe various information, such information should not be limited to these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope herein. It should be understood that the terms "X direction," "Y direction," "Z direction," and the like, indicate an orientation or positional relationship based on that shown in the drawings, merely for convenience in describing the present application and for simplicity in description, and do not indicate or imply that the device being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be considered as limiting the present application.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a three-axis gyroscope according to an embodiment of the present application, where the three-axis gyroscope may include: a substrate (not shown), and a Y-axis proof mass 20, two X/Z-axis

proof masses

30a, 30b, and two

driving masses

40a, 40b elastically connected to the substrate, respectively, disposed in parallel above the substrate. For convenience of description, two X/Z axis detection masses are defined as a first X/Z axis detection mass 30a and a second X/Z axis detection mass 30b, respectively, and two

driving masses

40a, 40b are defined as a first driving mass 40a and a second driving mass 40b, respectively.

The Y-axis proof mass 20 includes a first hollow 201, and as an example, the Y-axis proof mass 20 may have a frame-shaped or square-shaped structure, and preferably, the Y-axis proof mass 20 has a symmetrical pattern having an X-axis of symmetry and a Y-axis of symmetry. The first driving mass block 40a, the first X/Z axis detection mass block 30a, the second X/Z axis detection mass block 30b and the second driving mass block 40b are sequentially arranged and elastically connected along the X direction and are positioned in the first hollow part 201; the Y-axis detection mass 20 is elastically connected to the first driving mass 40a and the second driving mass 40b in the X direction, respectively. For example, the elastic connection may be achieved by a spring, and each elastic connection position may be provided with one spring, two springs or a plurality of springs for connection. In order to improve the stability of the movement, the parameters of the springs (e.g. spring length, spring rate, etc.) are preferably the same.

As an example of a symmetrical structure, the first driving mass 40a and the second driving mass 40b may be symmetrically disposed about a Y-direction symmetry axis, the first X/Z-axis detection mass 30a and the second X/Z-axis detection mass 30b may be symmetrically disposed about the Y-direction symmetry axis, and further, the first driving mass 40a, the second driving mass 40b, the first X/Z-axis detection mass 30a, and the second X/Z-axis detection mass 30b may be respectively symmetrical about an X-direction symmetry axis.

In the detection driving state, the first driving mass block 40a and the second driving mass block 40b are driven to perform resonant motion in opposite directions along the Y direction to form a pair of tuning fork type driving modules; the first X/Z-axis detection mass block 30a and the second X/Z-axis detection mass block 30b respectively perform resonant motion in opposite directions along the Y direction under the driving of the first driving mass block 40a and the second driving mass block 40b to form a pair of tuning fork type motions for detecting angular velocities around the X axis and the Z axis; the Y-axis detection mass 20 is driven by the first driving mass 40a and the second driving mass 40b to make reciprocating rotational motion in the XY plane for detecting the angular velocity around the Y axis.

During a resonant motion period, when the first driving mass block 40a is driven to move in the + Y direction and the second driving mass block 40 is driven to move in the-Y direction, during the half motion period, the first driving mass block 40a drives the first X/Z axis detecting mass block 30a to move in the + Y direction and the Y axis detecting mass block 20 to rotate clockwise, and the second driving mass block 40b drives the second X/Z axis detecting mass block 30b to move in the-Y direction and the Y axis detecting mass block 20 to rotate clockwise. When the first driving mass block 40a is driven to move in the-Y direction and the second driving mass block 40 is driven to move in the + Y direction, referring to the moving state of fig. 1, in the half moving period, the first driving mass block 40a drives the first X/Z axis detecting mass block 30a to move in the-Y direction and drive the Y axis detecting mass block 20 to rotate counterclockwise, and the second driving mass block 40b drives the second X/Z axis detecting mass block 30b to move in the + Y direction and drive the Y axis detecting mass block 20 to rotate counterclockwise.

The following description will be given taking the motion state of fig. 1 and the illustrated angular velocity as an example.

When there is an angular velocity Ω around the X-axis_xIn this case, according to the Coriolis effect principle, the first X/Z axis proof mass 30a is subjected to a Coriolis force in the + Z direction and tends to move in a direction away from the substrate, and the second X/Z axis proof mass 30b is subjected to a Coriolis force in the-Z direction and tends to move in a direction close to the substrate. Angular velocity about the X-axis omega driven by a full resonant motion_xThe first and second X/Z-

axis detection masses

30a and 30b are integrally oscillated about the Y-axis. According to the motion law, the detection of the angular velocity around the X axis can be realized.

When there is an angular velocity Ω around the Z-axis_zIn this case, according to the coriolis force principle, the first X/Z axis detection mass 30a is subjected to a coriolis force in the-X direction and tends to move in a direction close to the first driving mass 40a, and the second X/Z axis detection mass 30b is subjected to a coriolis force in the + X direction and tends to move in a direction close to the second driving mass 40 b. Angular velocity about the Z-axis omega driven by a full resonant motion_zThe first X/Z axis detection mass 30a and the second X/Z axis detection mass 30a are made to be parallelThe mass 30b as a whole undergoes periodic tensile and compressive movements in the X-direction. According to the motion rule, the detection of the angular velocity around the Z axis can be realized.

When there is an angular velocity Ω around the Y-axis_yIn the meantime, according to the coriolis force principle, the upper portion of the Y-axis detection mass 20 is subjected to a coriolis force in the-Z direction, and the lower portion of the Y-axis detection mass 20 is subjected to a coriolis force in the + Z direction, so that the Y-axis detection mass 20 tends to rotate about the X-axis. Angular velocity omega about the Y-axis driven by a full resonant motion_yThe Y-axis proof mass 20 is oscillated about the X-axis. According to the motion law, the detection of the angular velocity around the Y axis can be realized.

It can be understood that, in the three-axis gyroscope of the present embodiment, the pair of driving

masses

40a and 40b drives the Y-axis detection mass 20 and the two X/Z-

axis detection masses

30a and 30b to move, so that the angular velocities of the three axes (the angular velocities around the X-axis, the Y-axis, and the Z-axis) can be independently detected without interfering with each other, and the detection result is accurate. In addition, the three-axis gyroscope of the present embodiment not only uses a small number of masses (including only five masses), but also has two driving

masses

40a and 40b and two X/Z-

axis detection masses

30a and 30b both located in the first hollow 201 of the Y-axis detection mass 20, so that the overall structure is compact, the connection is simple, and the reliability is better.

In one embodiment, with continued reference to fig. 1, the substrate is provided with X-axis electrodes and two Z-axis electrodes arranged along the X-direction in the regions corresponding to each of the X/Z-axis proof masses. Specifically, the substrate is provided with an X-axis electrode 31a (i.e., a shown-X electrode) and two Z-

axis electrodes

32a and 32b arranged along the X direction on a region corresponding to the first X/Z-axis proof mass 30a, and is provided with an X-axis electrode 31b (i.e., a shown + X electrode) and two Z-

axis electrodes

32c and 32d arranged along the X direction on a region corresponding to the second X/Z-axis proof mass 30b, as an example of a symmetrical structure, the two

X-axis electrodes

31a and 31b may be symmetrically arranged about the Y-axis symmetry, the Z-

axis electrodes

32a and 32c may be symmetrically arranged about the Y-axis symmetry, the Z-

axis electrodes

32b and 32d may be symmetrically arranged about the Y-axis symmetry, and the two

X-axis electrodes

31a and 31b and the four Z-

axis electrodes

32a, 32b, 32c, 32b, 32d may each be symmetrical about the aforementioned X-axis of symmetry.

Taking the first X/Z axis detection mass block 30a as an example, the first X/Z axis detection mass block 30a is provided with a second hollow portion 301, two

Z axis electrodes

32a, 32b respectively extend from the substrate surface to the second hollow portion 301, and respectively form Z axis detection capacitors Cza, Czb with the first X/Z axis detection module 30a for detecting an angular velocity Ω around the Z axis_z(ii) a The X-axis electrode 31a is disposed opposite to the first X/Z-axis detection mass 30a to form an X-axis detection capacitance Cxa for detecting an angular velocity Ω around the X-axis_x. Similarly, the Z-

axis electrodes

32c and 32d and the first X/Z-axis detection module 30b respectively form Z-axis detection capacitors Czc and Czd, and the X-axis electrode 31b and the second X/Z-axis detection mass 30b form an X-axis detection capacitor Cxb.

In this embodiment, the angular velocity Ω around the X axis_xThe first X/Z axis detection mass block 30a and the second X/Z axis detection mass block 30b are enabled to swing integrally around the Y axis, the distances between the two electrodes of the X axis detection capacitors Cxa and Cxb can be changed, and omega can be realized through the change of the X axis detection capacitors_xDetection of (3). Angular velocity omega about the Z-axis_zThe first X/Z axis detection mass block 30a and the second X/Z axis detection mass block 30b are enabled to do periodic stretching and compressing motion along the X direction integrally, the distances between the two electrodes of the Z axis detection capacitors Cza, Czb, Czc and Czd can be changed, and omega can be detected through the change of the Z axis detection capacitors_zDetection of (3).

For example, for angular velocity Ω around the X-axis_xWhen there is an angular velocity omega about the X-axis_xAnd when the first X/Z axis detection mass block 30a is subjected to Coriolis force in the + Z direction, the distance between the first X/Z axis detection mass block 30a and the X axis electrode 31a is increased, the X axis detection capacitance Cxa is reduced, and simultaneously, because the second X/Z axis detection mass block 30b is subjected to Coriolis force in the-Z direction, the distance between the second X/Z axis detection mass block 30b and the X axis electrode 31b is reduced, the X axis detection capacitance Cxb is increased, the capacitance difference (differential capacitance) Cxb-Cxa and the angular velocity omega in the positive X direction are increased_zThe size is in positive correlation, and the capacitance difference Cxb-Cxa is X-direction angular velocity omega_xThe detection signal of (2), for example, can be detected by an ASIC circuit to obtain the total capacitance differenceAfter the capacitance variation is obtained, the angular velocity omega to be measured can be obtained through the steps of C-V conversion, signal processing and the like_x。

It is understood that the angular velocity Ω can be calculated by both Cxa and Cxb_xIn the embodiment, the total capacitance difference Cxb-Cxa is adopted for calculation, so that part of system errors can be offset, and the detection accuracy is improved.

For angular velocity Ω about the Z-axis_zAs an example, please refer to fig. 1 and fig. 2, fig. 2 is an enlarged schematic structural diagram of a portion a in fig. 1 according to an embodiment of the present application, and two side walls surrounding the second hollow portion 301 and arranged along the X direction respectively form a Z-axis detection capacitor with two Z-axis electrodes. Taking the first X/Z axis proof mass 30a as an example, the two

side walls

33a and 33b surrounding the second hollow portion 301 and arranged along the X direction and the two

Z axis electrodes

32a and 32b form a Z axis detection capacitor. It will be appreciated that Z-axis electrode 32a is opposite sidewall 33a and forms Z-axis sensing capacitor Cza, and Z-axis electrode 32b is opposite sidewall 33b and forms Z-axis sensing capacitor Czb. When there is an angular velocity Ω around the Z-axis_zAnd when the first X/Z-axis detection mass block 30a is subjected to coriolis force in the-X direction, the distance between the Z-axis electrode 32a and the side wall 33a increases, the Z-axis detection capacitor Cza decreases, the distance between the Z-axis electrode 32b and the side wall 33b decreases, the Z-axis detection capacitor Czb increases, and the capacitance difference (differential capacitor) Czb-Cza and the angular velocity Ω in the positive Z direction_zThe sizes are in positive correlation. Similarly, the second X/Z-axis proof mass 30b receives coriolis force in the + X direction, the Z-axis detection capacitances Czc and Czd decrease and increase, respectively, and the capacitance differences (differential capacitances) Czd-Czc and the angular velocity Ω in the positive Z direction_zThe sizes are in positive correlation, and the total capacitance difference Czb-Cza + Czd-Czc is the angular velocity omega in the Z direction_zThe detection signal of (1).

It can be understood that the angular velocity Ω z can be calculated by any one of Cza, Czb, Czc and Czd, and the present embodiment uses the total capacitance difference Czb-Cza + Czd-Czc for calculation, on one hand, by calculating two capacitance differences (Cza-Czb) and (Czd-Czc) respectively, it can counteract partial system errors, and improve the detection accuracy. On the other hand, the sum of the two capacitance differences can double the signal, thereby improving the detection sensitivity.

For angular velocity Ω about the Z-axis_zAs another example, please refer to fig. 1 and fig. 3, fig. 3 is an enlarged schematic structural diagram of a portion a in fig. 1 according to another embodiment of the present application, a first partition board 34 is disposed in the second hollow portion 301 to divide the second hollow portion 301 into two sub-areas arranged along the X direction; the two Z-axis electrodes extend into the two sub-regions, respectively, and are opposed to the two side surfaces of the first separator 34, respectively, to constitute two Z-axis detection capacitors. Taking the first X/Z axis proof mass 30a as an example, a first isolation plate 34 is disposed in the second hollow portion 301 to divide the second hollow portion 301 into two

sub-regions

301a and 301b arranged along the X direction, and two

Z axis electrodes

32a and 32b respectively extend into the two

sub-regions

301a and 301b and respectively face two

side surfaces

34a and 34b of the first isolation plate 34 to form two Z axis proof capacitances Cza and Czb. The Z-axis electrode 32a and the side surface 34a of the first spacer 34 form a Z-axis detection capacitor Cza, and the Z-axis electrode 32b and the side surface 34b of the first spacer 34 form a Z-axis detection capacitor Czb. The three-axis gyroscope of the present embodiment is aligned with an angular velocity Ω about the Z-axis_zThe detection principle is the same as that of the embodiment of fig. 2, and the description of this embodiment is omitted.

In one embodiment, referring to fig. 1, the Y-axis detection mass 20 includes a first sub-mass 21a, a second sub-mass 21b, a third sub-mass 21c, and a fourth sub-mass 21d sequentially connected end to form a first hollow portion 201, wherein the first sub-mass 21a and the third sub-mass 21c are arranged along the X direction, and the second sub-mass 21b and the fourth sub-mass 21d are arranged along the Y direction. It should be noted that the Y-axis detection mass 20 may be formed by integrating four sub-masses, or may be formed by connecting four separate masses by a connecting structure. The first driving mass block 40a, the first X/Z axis detection mass block 30a, the second X/Z axis detection mass block 30b and the second driving mass block 40b are sequentially arranged and elastically connected along the X direction, and are located in the first hollow portion 201. The first driving mass 40a is elastically connected to the inner side of the first sub-mass 21a, and the second driving mass 40b is elastically connected to the inner side of the third sub-mass 21 c. Two Y-

axis electrodes

22a and 22b are disposed on the substrate and respectively arranged opposite to the second sub-mass block 21b and the fourth sub-mass block 21d to form a Y-axis detection capacitor for detecting an angular velocity around the Y-axis. As one symmetrical structure example, the first sub-mass 21a and the third sub-mass 21c may be symmetrically disposed about the aforementioned Y-direction symmetry axis; the second sub-mass 21b and the fourth sub-mass 21d may be symmetrically disposed about the aforementioned X-direction symmetry axis, and each may be symmetric about the aforementioned Y-direction symmetry axis; the two Y-

axis electrodes

22a, 22b may be symmetrically disposed about the aforementioned X-axis symmetry axis.

Specifically, the Y-axis electrode 22a (i.e., the shown-Y electrode) and the second sub mass block 21b form a Y-axis detection capacitor Cya, and the Y-axis electrode 22b (i.e., the shown + Y electrode) and the fourth sub mass block 21d form a Y-axis detection capacitor Cyb. When there is an angular velocity Ω around the Y-axis_yAnd when the upper part (the fourth sub mass block 21 d) of the Y-axis detection mass block 20 is subjected to Coriolis force in the-Z direction, the distance between the Y-axis electrode 22b and the fourth sub mass block 21d is reduced, the Y-axis detection capacitance Cyb is increased, and meanwhile, because the lower part (the second sub mass block 21 b) of the Y-axis detection mass block 20 is subjected to Coriolis force in the + Z direction, the distance between the Y-axis electrode 22a and the second sub mass block 21b is increased, the Y-axis detection capacitance Cya is reduced, and the capacitance difference Cyb-Cya and the angular velocity omega in the positive Y direction are increased_yThe sizes are in positive correlation. The total electric capacity difference Cyb-Cya is Y direction angular velocity omega_yTo enable detection of angular velocity about the Y-axis.

It will be appreciated that the angular velocity Ω can be calculated by either Cya or Cyb_yIn the embodiment, the capacitance difference Cyb-Cya is adopted for calculation, so that part of system errors can be counteracted, and the detection accuracy is improved.

In one embodiment, the two ends of the first driving mass 40a in the Y direction and the two ends of the second driving mass 40b in the Y direction are connected to the substrate through first

elastic members

51a, 51b, 51c, 51d, respectively; the first driving mass 40a and the first X/Z axis proof mass 30a, and the second driving mass 40b and the second X/Z axis proof mass 30b are connected by second

elastic members

52a, 52b, 52c, 52d, respectively. The first driving mass 40a and the first sub-mass 21a, and the second driving mass 40b and the third sub-mass 21c are connected through third

elastic members

53a and 53b, respectively; the first X/Z axis proof mass 30a and the second X/Z axis proof mass 30b are connected at both ends in the Y direction by fourth

elastic members

54a, 54b, respectively.

Specifically, two ends of the first driving mass 40a in the Y direction are connected to the

anchors

10a and 10b of the substrate through the first

elastic members

51a and 51b, respectively, and two ends of the second driving mass 40b in the Y direction are connected to the

anchors

10c and 10d of the substrate through the first

elastic members

51c and 51d, respectively. The first driving mass 40a and the first X/Z axis sensing mass 30a are connected by second

elastic members

52a, 52b, and the second driving mass 40b and the second X/Z axis sensing mass 30b are connected by second

elastic members

52c, 52 d. The first driving mass 40a is connected to the first sub-mass 21a through a third elastic member 53a, and the second driving mass 40b is connected to the third sub-mass 21c through a third elastic member 53 b. The first X/Z-axis proof mass 30a and the second X/Z-axis proof mass 30b are connected to the anchors 10e and 10f of the substrate through the fourth

elastic members

54a and 54b at the two ends in the Y direction, respectively.

As one symmetrical structure example, the

anchor points

10a, 10b may be symmetrically disposed about the aforementioned X-direction axis of symmetry, and the anchor points 10c, 10d may be symmetrically disposed about the aforementioned X-direction axis of symmetry; the

anchor points

10a, 10d may be symmetrically disposed about the aforementioned Y-direction axis of symmetry, and the anchor points 10b, 10c may be symmetrically disposed about the aforementioned Y-direction axis of symmetry; the anchor points 10e, 10f may be provided on the aforementioned Y-direction axis of symmetry, and both are provided symmetrically with respect to the aforementioned X-direction axis of symmetry. The first

elastic members

51a, 51b may be disposed symmetrically about the aforementioned X-direction axis of symmetry, and the first

elastic members

51c, 51d may be disposed symmetrically about the aforementioned X-direction axis of symmetry; the first

elastic members

51a, 51d may be symmetrically disposed about the aforementioned Y-axis of symmetry, and the first

elastic members

51b, 51c may be symmetrically disposed about the aforementioned Y-axis of symmetry; the second

elastic members

52a, 52b may be disposed symmetrically about the aforementioned X-direction axis of symmetry, and the second

elastic members

52c, 52d may be disposed symmetrically about the aforementioned X-direction axis of symmetry; the second

elastic members

52a, 52d may be symmetrically disposed about the aforementioned Y-direction axis of symmetry, and the second

elastic members

52b, 52c may be symmetrically disposed about the aforementioned Y-direction axis of symmetry; the third

elastic members

53a, 53b may be disposed on the aforementioned X-direction symmetry axis and both disposed symmetrically with respect to the aforementioned Y-direction symmetry axis, and the fourth

elastic members

54a, 54b are each disposed symmetrically with respect to the aforementioned Y-direction symmetry axis and both disposed symmetrically with respect to the aforementioned X-direction symmetry axis.

It should be noted that only one or two or more second

elastic members

52a and 52b may be provided, and only one or two or more second

elastic members

52c and 52d may be provided, and the present application is not particularly limited.

As an example, the first elastic member and the second elastic member may be a folding beam having certain elasticity and bending property so that each of the connected members can be restored to an initial equilibrium state after the driving of the driving part is stopped.

As an example, the third

elastic element

53a, 53b may be a first flexible beam, such as a linear beam, with better bending and torsion properties, and the third elastic element 53a may enable the first driving mass 40a to move the first sub-mass 21a in resonance, and when there is an angular velocity Ω around the Y-axis_yAt this time, the Y-axis detection mass 20 may be twisted with respect to the first driving mass 40a by the third elastic member 53 a. The linear beam has better stability for low frequency (e.g., 10 kHz) resonant motion.

As an example, please refer to fig. 1 and 4, fig. 4 is a schematic structural diagram of a third elastic member according to an embodiment of the present application. The third

elastic members

53a, 53b may include a rectangular frame beam 531, and two second

flexible beams

532a, 532b respectively connected to opposite sides of the rectangular frame beam 531. The rectangular frame beam 531 is connected to the first sub-mass 21a via the second flexible beam 532a and to the first driving mass 40a via the second flexible beam 532b near the third elastic member 53a on one side of the first sub-mass 21 a. The rectangular frame beam 531 is connected to the second driving mass 40b via a second flexible beam 532a, and is connected to the third sub-mass 21c via a second flexible beam 532b, near the third elastic member 53b on one side of the third sub-mass 21 c. The third elastic element of the embodiment has better stability for high-frequency resonance, for example, the resonance frequency is 20-30 kHz.

As an example, please refer to fig. 1 and fig. 5, fig. 5 is a schematic structural diagram of a fourth elastic member according to an embodiment of the present application. The fourth

elastic members

54a and 54b may include a rigid beam 541 disposed parallel to the X direction, and a third flexible beam 542 and two fourth

flexible beams

543a and 543b vertically connected to one side of the rigid beam 541 near the X/Z axis detection mass, wherein the third flexible beam 542 is located between the two fourth

flexible beams

543a and 543 b. Referring to fig. 1, the rigid beams 541 are connected to the substrate via third flexible beams 542, the first X/Z axis proof mass 30a via one fourth flexible beam 543a, and the second X/Z axis proof mass 30b via another fourth flexible beam 543 b. In this embodiment, the rigid beam 541 and the third flexible beam 542 form a T-shaped beam, and the first X/Z axis detection mass block 30a and the second X/Z axis detection mass block 30b are elastically connected to the substrate through the two fourth

flexible beams

543a and 543b and the T-shaped beam, so that the first X/Z axis detection mass block 30a and the second X/Z axis detection mass block 30b keep the motion synchronization under the coriolis force, and after the driving is stopped, the mechanical decoupling is realized, and the gyroscope has better zero-offset stability.

In one embodiment, referring to fig. 1, the driving

masses

40a and 40b include a third hollow portion 401, and the three-axis gyroscope further includes driving portions corresponding to the two driving masses, respectively, and the driving portions are located in the third hollow portion 401 to drive the driving masses to perform a resonant motion. The driving portion may be an electrostatic comb structure, for example, the driving portion includes two

electrostatic comb structures

41a and 41b arranged along the Y direction, and as an example of a symmetrical structure, the driving portions corresponding to the two driving masses are symmetrical about the Y-direction symmetry axis; the two electrostatic

comb tooth structures

41a, 41b of each drive section are arranged symmetrically with respect to the aforementioned X-direction symmetry axis.

As an example, please refer to fig. 1 and 6, fig. 6 is an enlarged structural schematic diagram of the electrostatic comb tooth structure in fig. 1. Taking the first driving mass block 40a as an example, the electrostatic comb tooth structure 41a may include a movable comb tooth 411 connected to the first driving mass block 40a, and two fixed

comb teeth

412a and 412b fixedly connected to the substrate, respectively, the movable comb tooth 411 and the two fixed

comb teeth

412a and 412b being arranged along the Y direction, and the two fixed

comb teeth

412a and 412b being located at both sides of the movable comb tooth 411, respectively. The movable comb tooth 411 and one fixed comb tooth 412a form a drive capacitance Cdra, and the other fixed comb tooth 412b form a drive detection capacitance Cdrsb. During driving, a voltage Vpm + Vac × sin (ω t) may be applied to the movable comb teeth 411 of the two driving

masses

40a and 40b, where Vpm is a dc voltage, Vac is an ac voltage amplitude, and ω is an angular frequency of a driving mode of the three-axis gyroscope, a dc voltage Vdc is applied to the fixed comb teeth 412a of the first driving mass 40a, and a dc voltage-Vdc is applied to the fixed comb teeth 412a of the second driving mass 40b, and under the driving of the voltages, the two driving

masses

40a and 40b perform an anti-phase motion along the Y axis and simultaneously drive the two X/Z

axis detection masses

30a and 30b to move. The driving capacitor Cdra and the driving detection capacitor Cdrsb form a positive feedback structure, so that the motion frequency and amplitude of the first driving mass block 40a can be locked.

Further, the movable comb 411 includes a second isolation plate 4111 erected in the third hollow portion 401 along the X direction and connected to the driving mass block, two side surfaces of the second isolation plate 4111 are respectively provided with

comb teeth

4112a, 4112b arranged in parallel along the X direction, wherein a driving capacitance Cdra is formed between the comb tooth 4112a on one side surface and the corresponding fixed comb tooth 412a, and a driving detection capacitance Cdrsb is formed between the comb tooth 4112b on the other side surface and the corresponding fixed comb tooth 412 b.

It should be noted that, as a preferred embodiment, referring to fig. 1, the three-axis gyroscope has an X-axis of symmetry and a Y-axis of symmetry. Namely, the structures of the three-axis gyroscope are symmetrical left and right and symmetrical up and down. The symmetrical structure can eliminate zero point offset caused by factors such as stress and the like, and reduce the correction frequency of the triaxial gyroscope.

The foregoing detailed description is directed to a three-axis gyroscope provided in an embodiment of the present application, and specific examples are applied in this disclosure to explain the principles and embodiments of the present application, and the description of the foregoing embodiments is only used to help understand the method and the core ideas of the present application; meanwhile, for those skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.

Claims

1. A triaxial gyroscope is characterized by comprising a substrate, a Y-axis detection mass block, two X/Z-axis detection mass blocks and two driving mass blocks, wherein the Y-axis detection mass blocks, the two X/Z-axis detection mass blocks and the two driving mass blocks are arranged above the substrate in parallel; the two X/Z-axis detection mass blocks are respectively a first X/Z-axis detection mass block and a second X/Z-axis detection mass block, and the two driving mass blocks are respectively a first driving mass block and a second driving mass block;

the Y-axis detection mass block comprises a first hollow part;

2. The triaxial gyroscope of claim 1, wherein the substrate is provided with an X-axis electrode and two Z-axis electrodes arranged along the X direction at the same time on the area corresponding to each X/Z-axis detection mass;

3. The three-axis gyroscope of claim 2, wherein two side walls surrounding the second hollow portion and arranged along the X direction and the two Z-axis electrodes respectively form the Z-axis detection capacitor.

4. The triaxial gyroscope of claim 2, wherein a first partition plate is disposed within the second hollowed-out portion to divide the second hollowed-out portion into two sub-regions arranged along the X-direction;

the two Z-axis electrodes extend into the two sub-areas respectively and are opposite to the two side faces of the first isolation plate respectively to form two Z-axis detection capacitors.

5. The tri-axial gyroscope of claim 1, wherein the drive mass includes a third hollowed-out portion;

6. The three-axis gyroscope of claim 5, wherein the drive section comprises two electrostatic comb structures arranged along the Y-direction;

7. The triaxial gyroscope of claim 6, wherein the movable comb teeth include a second isolation plate that is mounted in the third hollow portion along the X-direction and is connected to the driving mass block, and comb teeth arranged along the X-direction are respectively disposed on two side surfaces of the second isolation plate, wherein a driving capacitance is formed between the comb teeth on one side surface and the corresponding fixed comb teeth, and a driving detection capacitance is formed between the comb teeth on the other side surface and the corresponding fixed comb teeth.

8. The triaxial gyroscope of any of claims 1 to 7, wherein the Y-axis sensing masses comprise a first sub-mass, a second sub-mass, a third sub-mass and a fourth sub-mass connected end to end in sequence to enclose the first hollow, wherein the first sub-mass and the third sub-mass are arranged along an X-direction, and the second sub-mass and the fourth sub-mass are arranged along a Y-direction;

9. The triaxial gyroscope of claim 8, wherein both ends of the first driving mass in the Y direction and both ends of the second driving mass in the Y direction are connected to the substrate through first elastic members, respectively; the first driving mass block and the first X/Z-axis detection mass block, and the second driving mass block and the second X/Z-axis detection mass block are respectively connected through second elastic pieces;

10. The tri-axial gyroscope of claim 9, wherein the third spring is a first flexible beam; or the third elastic piece comprises a rectangular frame beam and two second flexible beams which are respectively connected to two opposite sides of the rectangular frame beam;