CN117929785A - Acceleration sensor - Google Patents

Abstract

The invention provides an acceleration sensor, which comprises a first acceleration detection unit, a second acceleration detection unit, a substrate, a connecting arm, a first anchor point, a first elastic piece and a second elastic piece, wherein the first anchor point is connected with the substrate; the first acceleration detection unit is used for detecting acceleration along the out-of-plane Z-axis direction; the first acceleration detection unit comprises a first teeter-totter unit and a second teeter-totter unit, the first teeter-totter unit and the second teeter-totter unit are arranged oppositely, and the first teeter-totter unit and the second teeter-totter unit are enclosed to form an annular structure; the second acceleration detection unit is used for detecting acceleration along the in-plane X-axis direction and/or the in-plane Y-axis direction; the annular structure surrounds the outer side of the second acceleration detection unit; the connecting arm is fixed on the substrate through the first anchor point; the connecting arm is located between the first acceleration detection unit and the second acceleration detection unit. The invention has the technical effects of reasonable structural design and stronger anti-interference capability.

Description

Acceleration sensor

Technical Field

The invention belongs to the technical field of sensors, and particularly relates to an acceleration sensor.

Background

The acceleration sensor comprises one or more proof masses for detecting acceleration. For example, some acceleration sensors include a proof mass configured to move in a plane to detect acceleration in the plane of the proof mass, and the proof mass is configured to move out of the plane to detect acceleration perpendicular to the plane of the proof mass. Acceleration may be detected using a capacitive sensor coupled to the proof mass.

At present, when the acceleration sensor detects in-plane acceleration and out-of-plane speed, the in-plane detection structure and the out-of-plane detection structure are respectively fixed on the substrate, so that the whole structure of the acceleration sensor is greatly influenced by factors such as stress, and the anti-interference capability of the acceleration sensor is not improved.

Disclosure of Invention

The invention aims to at least solve one of the technical problems in the prior art and provides a novel technical scheme of an acceleration sensor.

According to an aspect of the present invention, there is provided an acceleration sensor including:

A first acceleration detection unit for detecting acceleration in an out-of-plane Z-axis direction; the first acceleration detection unit comprises a first teeter-totter unit and a second teeter-totter unit, the first teeter-totter unit and the second teeter-totter unit are arranged oppositely, and the first teeter-totter unit and the second teeter-totter unit are enclosed to form an annular structure;

A second acceleration detection unit for detecting acceleration in an in-plane X-axis direction and/or an in-plane Y-axis direction; the annular structure surrounds the outer side of the second acceleration detection unit;

The device comprises a substrate, a connecting arm and a first anchor point, wherein the first anchor point is positioned in the middle of the substrate, and the connecting arm is fixed on the substrate through the first anchor point; the connecting arm is positioned between the first acceleration detection unit and the second acceleration detection unit;

the first acceleration detection unit is connected with the connecting arm through the first elastic piece; the second acceleration detection unit is connected with the connecting arm through the second elastic piece;

The out-of-plane Z-axis direction, the in-plane X-axis direction and the in-plane Y-axis direction are perpendicular to each other.

Optionally, the first acceleration detection unit further comprises an out-of-plane displacement detection unit;

The middle part of the connecting arm, which is close to one side of the second acceleration detection unit, is fixed on the first anchor point;

The first seesaw unit is elastically connected with the first end of the connecting arm, and the second seesaw unit is elastically connected with the second end of the connecting arm; the first seesaw units and the second seesaw units are symmetrically distributed along the symmetry axis of the acceleration sensor respectively; the first teeterboard units respectively form two first teeterboard structures on two sides of the symmetry axis, and the two first teeterboard structures rotate along the first rotation axis; the second seesaw units respectively form two second seesaw structures on two sides of the symmetrical shaft, and the two second seesaw structures rotate along a second rotating shaft; the first rotating shaft and the second rotating shaft are arranged in parallel, and the first rotating shaft and the second rotating shaft are perpendicular to the symmetry axis;

The first seesaw unit and the second seesaw unit are respectively provided with the out-of-plane displacement detection unit.

Optionally, the outside of first seesaw unit is provided with first recess, the inboard of second seesaw unit is provided with the second recess, part first seesaw unit inlays and locates in the second recess and part second seesaw unit inlays and locates in the first recess in order to form nested structure, nested structure is located between first pivot and the second pivot.

Optionally, the acceleration sensor further comprises a first proof mass and a second proof mass;

Each first seesaw structure comprises a first sub-rotating part and a second sub-rotating part, the first sub-rotating parts and the second sub-rotating parts are respectively positioned at two opposite sides of the first rotating shaft, and a first groove is formed in the outer side of the second sub-rotating parts; each second seesaw structure comprises a third sub-rotating part and a fourth sub-rotating part, wherein the third sub-rotating part and the fourth sub-rotating part are respectively positioned at two opposite sides of the second rotating shaft, and a second groove is formed in the inner side of the third sub-rotating part;

The first detection mass block is located at the first sub-rotating part, the second detection mass block is located at the fourth sub-rotating part, and the first detection mass block and the second detection mass block are symmetrically arranged.

Optionally, the acceleration sensor further includes a coupling beam, the coupling beam extends along a direction perpendicular to the symmetry axis, one end of the coupling beam is connected to the second sub-rotating part, and the other end of the coupling beam is connected to the third sub-rotating part.

Optionally, the second acceleration detection unit is used for detecting acceleration along an in-plane X-axis direction, the second elastic piece is an X-axis single-degree-of-freedom spring distributed along an in-plane Y-axis direction, and the second acceleration detection unit is fixed on the connecting arm through the X-axis single-degree-of-freedom spring;

The second acceleration detection unit comprises a first mass block and a first capacitor bank; first mounting grooves distributed along the Y-axis direction in the plane are formed in the first mass block at intervals, and a first capacitor group is arranged in each first mounting groove;

the first capacitor group comprises a first positive fixed electrode and a first negative fixed electrode, and the first positive fixed electrode and the first negative fixed electrode are distributed along the Y-axis direction in the plane; one side of the first positive fixed electrode, which is far away from the first negative fixed electrode, and the first mass block form a first differential detection capacitor, and one side of the first negative fixed electrode, which is far away from the first positive fixed electrode, and the first mass block form a second differential detection capacitor.

Optionally, the second acceleration detection unit is used for detecting acceleration along the in-plane Y axis direction, the second elastic piece is a Y axis single degree of freedom spring distributed along the in-plane X axis direction, and the second acceleration detection unit is fixed on the connecting arm through the Y axis single degree of freedom spring;

The second acceleration detection unit comprises a second mass block and a second capacitor bank; second mounting grooves distributed along the X-axis direction in the plane are formed in the middle of the second mass block at intervals, and a second capacitor group is arranged in each second mounting groove;

The second capacitor group comprises a second positive fixed electrode and a second negative fixed electrode, and the second positive fixed electrode and the second negative fixed electrode are distributed along the X-axis direction in the plane; and one side of the second positive fixed electrode, which is far away from the second negative fixed electrode, and the second mass block form a third differential detection capacitor, and one side of the second negative fixed electrode, which is far away from the second positive fixed electrode, and the second mass block form a fourth differential detection capacitor.

Optionally, the annular structure surrounds the outer side of the connecting arm;

the connecting arm is provided with a containing groove for installing the second acceleration detection unit;

the first anchor point is located at the center of the connecting arm.

Optionally, the two accommodating grooves are symmetrically arranged.

Optionally, each accommodating groove is internally provided with one second acceleration detection unit;

The second acceleration detection unit is used for detecting the acceleration in the X-axis direction in the plane; the other second acceleration detection unit is used for detecting acceleration in the Y-axis direction in the plane.

The invention has the technical effects that:

In the embodiment of the application, the first acceleration detection unit is used for detecting acceleration along the out-of-plane Z-axis direction; the first acceleration detection unit comprises a first teeter-totter unit and a second teeter-totter unit, the first teeter-totter unit and the second teeter-totter unit are oppositely arranged, and the first teeter-totter unit and the second teeter-totter unit enclose to form an annular structure. The second acceleration detection unit is used for detecting acceleration along the in-plane X-axis direction and/or the in-plane Y-axis direction; the annular structure surrounds the outer side of the second acceleration detection unit. The first anchor point is positioned in the middle of the substrate, and the connecting arm is fixed on the substrate through the first anchor point; the connecting arm is positioned between the first acceleration detection unit and the second acceleration detection unit; the first acceleration detection unit is connected with the connecting arm through a first elastic piece; the second acceleration detection unit is connected with the connecting arm through a second elastic piece.

Therefore, the first anchor point is arranged at the structural center of the acceleration sensor, and the first anchor point is shared by the first acceleration detection and the second acceleration detection through the connecting arm, so that the integral structure of the acceleration sensor is less influenced by factors such as stress, and the anti-interference capability of the acceleration sensor is obviously improved.

Drawings

Fig. 1 is a schematic structural diagram of an acceleration sensor according to a first embodiment of the present invention;

fig. 2 is a schematic view of a detection mode of an in-plane X-axis direction of an acceleration sensor according to a first embodiment of the present invention;

FIG. 3 is a schematic view of a detection mode of an out-of-plane Z-axis direction of an acceleration sensor according to a first embodiment of the present invention;

FIG. 4 is a schematic view of parasitic modes in the out-of-plane Z-axis direction of an acceleration sensor according to a first embodiment of the present invention;

Fig. 5 is a schematic structural view of a coupling beam of an acceleration sensor according to a first embodiment of the present invention;

Fig. 6 is a schematic structural diagram of an acceleration sensor according to a second embodiment of the present invention;

FIG. 7 is a schematic view of a detection mode of an in-plane X-axis direction of an acceleration sensor according to a second embodiment of the present invention;

FIG. 8 is a schematic diagram of a detection mode of an out-of-plane Z-axis direction of an acceleration sensor according to a second embodiment of the present invention;

FIG. 9 is a schematic view of parasitic modes in the out-of-plane Z-axis direction of an acceleration sensor according to a second embodiment of the present invention;

fig. 10 is a schematic structural diagram of an acceleration sensor according to a third embodiment of the present invention;

FIG. 11 is a schematic view of a detection mode of an in-plane Y-axis direction of an acceleration sensor according to a third embodiment of the present invention;

FIG. 12 is a schematic view of a detection mode of an out-of-plane Z-axis direction of an acceleration sensor according to a third embodiment of the present invention;

FIG. 13 is a schematic view of parasitic modes in the out-of-plane Z-axis direction of an acceleration sensor according to a third embodiment of the present invention;

Fig. 14 is a schematic structural view of a coupling beam of an acceleration sensor according to a third embodiment of the present invention;

FIG. 15 is a schematic view of an X-axis single degree of freedom spring of an acceleration sensor according to an embodiment of the present invention;

FIG. 16 is a schematic view of a Y-axis single degree of freedom spring of an acceleration sensor according to an embodiment of the present invention;

Fig. 17 is a schematic structural view of an acceleration sensor according to a fourth embodiment of the present invention;

Fig. 18 is a schematic view of a detection mode of an in-plane X-axis direction of an acceleration sensor according to a fourth embodiment of the present invention;

FIG. 19 is a schematic view of a detection mode of an in-plane Y-axis direction of an acceleration sensor according to a fourth embodiment of the present invention;

FIG. 20 is a schematic view of a detection mode of an out-of-plane Z-axis direction of an acceleration sensor according to a fourth embodiment of the present invention;

FIG. 21 is a schematic view of parasitic modes in the out-of-plane Z-axis direction of an acceleration sensor according to a fourth embodiment of the present invention;

Fig. 22 is a schematic structural view of a coupling beam of an acceleration sensor according to a fourth embodiment of the present invention;

FIG. 23 is a schematic diagram showing a structure of a first capacitive group of an acceleration sensor according to an embodiment of the present invention;

FIG. 24 is a schematic diagram of a second implementation of a first capacitive set of an acceleration sensor according to an embodiment of the present invention;

FIG. 25 is a schematic diagram showing a structure of a first implementation of a second capacitive set of an acceleration sensor according to an embodiment of the present invention;

fig. 26 is a schematic structural diagram of a second implementation of the second capacitor set of the acceleration sensor according to an embodiment of the present invention.

In the figure: 100. a symmetry axis; 200. a first rotating shaft; 300. a second rotating shaft; 11. a first anchor point; 12. a second anchor point; 2. a first elastic member; 3. a second elastic member; 31. x-axis single-degree-of-freedom spring; 32. a Y-axis single-degree-of-freedom spring; 4. a connecting arm; 41. a receiving groove; 5. a first acceleration detection unit; 51. a first seesaw unit; 511. a first groove; 512. a first sub-rotating part; 513. a second sub-rotating part; 52. a second seesaw unit; 521. a second groove; 522. a third sub-rotating part; 523. fourth sub-turn

A moving part; 53. an out-of-plane displacement detection unit; 6. a second acceleration detection unit; 611. a first mass; 612. a first mounting groove; 613. a first positive fixed electrode; 614. first, the

A negative fixed electrode; 615. a first fixed electrode; 616. a first movable electrode; 621. a second mass; 622. a second mounting groove; 623. a second positive fixed electrode; 624. a second negative fixed electrode; 625. a second fixed electrode; 626. a second movable electrode; 71. a first proof mass; 72. a second proof mass; 8. and a coupling beam.

Detailed Description

Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present application unless it is specifically stated otherwise.

Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements throughout or elements having like or similar functionality. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The features of the application "first", "second" and the like in the description and in the claims may be used for the explicit or implicit inclusion of one or more such features. In the description of the present application, unless otherwise indicated, the meaning of "a plurality" is two or more. Furthermore, in the description and claims, "and/or" means at least one of the connected objects, and the character "/", generally means that the associated object is an "or" relationship.

In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.

Example 1

Referring to fig. 1 to 5 and 23 and 25, according to an aspect of the present invention, an acceleration sensor is provided. For convenience in explaining the acceleration sensor of the present invention, an X-Y-Z axis three-dimensional coordinate system is established, and an in-plane X axis direction, an in-plane Y axis direction, and an out-of-plane Z axis direction are defined to be perpendicular to each other with reference to fig. 1.

Specifically, the acceleration sensor includes a first acceleration detecting unit 5, a second acceleration detecting unit 6, a base, a connecting arm 4, a first anchor point 11, a first elastic member 2, and a second elastic member 3; the first acceleration detection unit 5 is used for detecting acceleration along the out-of-plane Z-axis direction; the first acceleration detection unit 5 comprises a first seesaw unit 51 and a second seesaw unit 52, wherein the first seesaw unit 51 and the second seesaw unit 52 are oppositely arranged, and the first seesaw unit and the second seesaw unit are enclosed to form an annular structure; the second acceleration detection unit 6 is configured to detect acceleration in an in-plane X-axis direction and/or an in-plane Y-axis direction.

In one embodiment, the second acceleration detection unit 6 is configured to detect acceleration in the in-plane X-axis direction. At this time, the acceleration sensor is capable of detecting acceleration in the in-plane X-axis direction and acceleration in the out-of-plane Z-axis direction simultaneously to form a biaxial (in-plane X-axis and out-of-plane Z-axis) accelerometer.

In another embodiment, the second acceleration detection unit 6 is configured to detect acceleration in the in-plane Y-axis direction. At this time, the acceleration sensor is capable of detecting acceleration in the in-plane Y-axis direction and acceleration in the out-of-plane Z-axis direction simultaneously to form a biaxial (in-plane Y-axis and out-of-plane Z-axis) accelerometer.

In other embodiments, the second acceleration detection unit 6 is capable of detecting acceleration in the in-plane X-axis direction and acceleration in the in-plane Y-axis direction at the same time. At this time, the acceleration sensor is capable of detecting acceleration in the in-plane X-axis direction, in-plane Y-axis direction, and acceleration in the out-of-plane Z-axis direction simultaneously to form a three-axis (in-plane X-axis, in-plane Y-axis, and out-of-plane Z-axis) accelerometer.

Further specifically, the annular structure surrounds the outside of the second acceleration detection unit 6; the first anchor point 11 is positioned in the middle of the substrate, and the connecting arm 4 is fixed on the substrate through the first anchor point 11; the connecting arm 4 is located between the first acceleration detection unit 5 and the second acceleration detection unit 6; the first acceleration detection unit 5 is connected with the connecting arm 4 through the first elastic member 2; the second acceleration detection unit 6 is connected with the connecting arm 4 through the second elastic member 3; the out-of-plane Z-axis direction, the in-plane X-axis direction and the in-plane Y-axis direction are perpendicular to each other.

It should be noted that the first acceleration detecting unit 5 is elastically connected to the connecting arm 4, so as to provide flexible support for the linear movement of the proof mass on the first acceleration detecting unit 5 along the in-plane X-axis direction and/or the in-plane Y-axis direction, and to co-couple the movement of the first acceleration detecting unit 5 along the out-of-plane Z-axis direction. At the same time, the second acceleration detection unit 6 is elastically connected to the connecting arm 4 for providing flexible support for the linear movement of the proof mass on the second acceleration detection unit 6 in the in-plane X-axis direction and/or in-plane Y-axis direction and for co-coupling the movement of the first acceleration detection unit 5 in the out-of-plane Z-axis direction.

In the embodiment of the application, the first anchor point 11 is arranged in the center of the structure of the acceleration sensor, and the first anchor point 11 is shared by the first acceleration detection and the second acceleration detection through the connecting arm 4, so that the whole structure of the acceleration sensor is less influenced by factors such as stress, and the anti-interference capability of the acceleration sensor is obviously improved.

Illustratively, the acceleration sensors are symmetrically distributed along their symmetry axis 100; and the first seesaw unit 51 and the second seesaw unit 52 are symmetrically distributed along the symmetry axis 100.

Optionally, the first acceleration detection unit 5 further includes an out-of-plane displacement detection unit 53;

the middle part of the connecting arm 4, which is close to one side of the second acceleration detection unit 6, is fixed on the first anchor point 11;

The first seesaw unit 51 is elastically connected with the first end of the connecting arm 4, and the second seesaw unit 52 is elastically connected with the second end of the connecting arm 4; the first seesaw unit 51 and the second seesaw unit 52 are symmetrically distributed along the symmetry axis 100 of the acceleration sensor, respectively; the first teeter-totter units 51 respectively form two first teeter-totter structures on two sides of the symmetry axis 100, and the two first teeter-totter structures rotate along the first rotation axis 200; the second teeter-totter units 52 respectively form two second teeter-totter structures at both sides of the symmetry axis 100, and the two second teeter-totter structures both rotate along the second rotation axis 300; the first rotating shaft 200 and the second rotating shaft 300 are arranged in parallel, and the first rotating shaft 200 and the second rotating shaft 300 are perpendicular to the symmetry axis 100;

the first seesaw unit 51 and the second seesaw unit 52 are each provided with the out-of-plane displacement detecting unit 53.

In the above embodiment, the first and second seesaw units 51 and 52 are employed as the surface-applied-speed detection structure, so that the first and second seesaw units 51 and 52 can reversely rotate in the Y-axis direction by the acceleration in the out-of-plane Z-axis direction, that is, the surface-applied-speed (i.e., Z-axis acceleration) of the acceleration sensor can be detected by the out-of-plane displacement detection unit 53 provided on the first and second seesaw units 51 and 52. Meanwhile, when the two first teeter-totter structures or the two second teeter-totter structures are subjected to the action of the unexpected Y-axis angular acceleration, the two first teeter-totter structures or the two second teeter-totter structures rotate in the same direction, and the capacitance change of the out-of-plane displacement detection unit 53 caused by the rotation in the same direction is counteracted when the out-of-plane displacement detection unit 53 detects, so that the layout of the two first teeter-totter structures and the two second teeter-totter structures greatly reduces the influence of the Y-axis angular acceleration on the acceleration sensor, improves the cross inhibition ratio of the acceleration sensor, and improves the accuracy of the detection of the out-of-plane applied speed of the acceleration sensor.

Optionally, a first groove 511 is provided on the outer side of the first seesaw unit 51, a second groove 521 is provided on the inner side of the second seesaw unit 52, a part of the first seesaw unit 51 is embedded in the second groove 521, and a part of the second seesaw unit 52 is embedded in the first groove 511 to form a nested structure, and the nested structure is located between the first rotating shaft 200 and the second rotating shaft 300.

In the above embodiment, the first seesaw unit 51 and the second seesaw unit 52 are nested. The nested structure helps to lengthen the rotating arms of the first and second seesaw units 51 and 52, while the out-of-plane displacement detecting unit 53 may be disposed at a region farther from the rotation axis, thereby making the gain of the out-of-plane velocity detection larger.

Optionally, the acceleration sensor further comprises a first proof mass 71 and a second proof mass 72;

Each of the first teeter-totter structures comprises a first sub-rotating part 512 and a second sub-rotating part 513, wherein the first sub-rotating part 512 and the second sub-rotating part 513 are respectively positioned at two opposite sides of the first rotating shaft 200, and a first groove 511 is arranged at the outer side of the second sub-rotating part 513; each second teeter-totter structure comprises a third sub-rotating part 522 and a fourth sub-rotating part 523, wherein the third sub-rotating part 522 and the fourth sub-rotating part 523 are respectively positioned at two opposite sides of the second rotating shaft 300, and a second groove 521 is formed at the inner side of the third sub-rotating part 522;

The first proof mass 71 is located at the first sub-rotating portion 512, the second proof mass 72 is located at the fourth sub-rotating portion 523, and the first proof mass 71 and the second proof mass 72 are symmetrically disposed.

In the above embodiment, the first proof mass 71 and the second proof mass 72 form an asymmetric proof mass located at the distal end of the teeter-totter structure, so that the rotation of the first teeter-totter structure and the second teeter-totter structure due to the surface applied speed is more sensitive, thereby improving the gain of the acceleration sensor detection.

Illustratively, the first detecting mass is set at the position where the two first sub-rotating parts 512 are connected, and the second detecting mass is set at the position where the two fourth sub-rotating parts 523 are connected, which helps to further increase the distance between the detecting mass and the rotating shaft, so that the rotation of the first teeter-totter structure and the second teeter-totter structure caused by the surface applied speed is significantly improved to be more sensitive, so as to further improve the gain detected by the acceleration sensor.

Optionally, the acceleration sensor further includes a coupling beam 8, wherein the coupling beam 8 extends in a direction perpendicular to the symmetry axis 100, and one end of the coupling beam 8 is connected to the second sub-rotation part 513, and the other end is connected to the third sub-rotation part 522.

In the above embodiment, by providing the coupling beam 8 between the first seesaw unit 51 and the second seesaw unit 52, the coupling beam 8 can weaken the co-rotation of the first seesaw unit 51 and the second seesaw unit 52, further suppress the influence of the y-axis angular acceleration, and contribute to further improving the accuracy of the acceleration sensor in detecting the applied velocity.

In a specific embodiment, the first sub-rotating portion 512, the second sub-rotating portion 513, the third sub-rotating portion 522, and the fourth sub-rotating portion 523 are each provided with an out-of-plane displacement detecting unit 53, and a part of the out-of-plane displacement detecting unit 53 is located at a position where the first seesaw unit 51 is away from the first rotation axis 200, and a part of the out-of-plane displacement detecting unit 53 is located at a position where the second seesaw unit 52 is away from the second rotation axis 300. The plurality of out-of-plane displacement detecting units 53 are symmetrically distributed along the symmetry axis 100.

Illustratively, the coupling beam 8 is strip-shaped, and one end of the coupling beam 8 is fixed to the bottom wall of the first groove 511 and the other end is fixed to the bottom wall of the second groove 521. This makes the structure of the coupling beam 8 relatively simple, facilitating the assembly of the acceleration sensor.

In some embodiments, the coupling beam 8 comprises two mutually parallel sub-beams. One end of the sub beam is fixed to the bottom wall of the first groove 511, and the other end is fixed to the bottom wall of the second groove 521. This further improves the ability of the coupling beam 8 to weaken the co-rotation of the first and second see-saw units 51 and 52, thereby better suppressing the influence of the y-axis angular acceleration.

In other embodiments, the coupling beam 8 is in the shape of a rectangular ring. The middle part of one side of the coupling beam 8 is fixed to the inner sidewall of the first groove 511, and the middle part of the other side of the coupling beam 8 is fixed to the inner sidewall of the second groove 521. This makes the structural design of the coupling beam 8 reasonable, and can effectively weaken the ability of the first and second seesaw units 51 and 52 to rotate in the same direction.

Alternatively, two of said connecting arms 4 are symmetrically distributed along said symmetry axis 100; each of the connecting arms 4 is fixed to the base by one of the first anchor points 11, and two of the first anchor points 11 are located between two of the connecting arms 4.

Alternatively, referring to fig. 1 and 23, the second acceleration detecting unit 6 is configured to detect acceleration along an in-plane X-axis direction, the second elastic member 3 is an X-axis single-degree-of-freedom spring 31 distributed along an in-plane Y-axis direction, and the second acceleration detecting unit 6 is fixed to the connecting arm 4 through the X-axis single-degree-of-freedom spring 31;

The second acceleration detection unit 6 comprises a first mass 611 and a first capacitive group; first mounting grooves 612 distributed along the Y-axis direction in the plane are formed in the first mass block 611 at intervals, and a first capacitor group is arranged in each first mounting groove 612;

The first capacitor group comprises a first positive fixed electrode 613 and a first negative fixed electrode 614, and the first positive fixed electrode 613 and the first negative fixed electrode 614 are distributed along the Y-axis direction in the plane; the side of the first positive fixed electrode 613 far from the first negative fixed electrode 614 forms a first differential detection capacitance with the first mass block 611, and the side of the first negative fixed electrode 614 far from the first positive fixed electrode 613 forms a second differential detection capacitance with the first mass block 611.

Referring to fig. 23, when the first mass block 611 is displaced to the left by the acceleration to the left along the X-axis, the capacitance interval of the first differential detection capacitor is reduced, the capacitance interval of the second differential detection capacitor is increased, the first differential detection capacitor and the second differential detection capacitor are changed in proportion to the capacitance difference of the acceleration to the left along the X-axis, and the real-time value of the acceleration to the left along the X-axis can be obtained by detecting the change of the capacitance difference.

Similarly, when the first mass 611 is displaced rightward by the rightward acceleration along the X-axis, a real-time value of the rightward acceleration along the X-axis can be obtained by detecting the change in the capacitance value.

In the above embodiment, the second acceleration detection unit 6 has a reasonable structural design, and can accurately measure the in-plane X-axis acceleration.

For example, referring to fig. 15, the X-axis single degree-of-freedom spring 31 may be designed in different shapes according to the specific structure of the acceleration sensor to better enable the detection of the in-plane X-axis acceleration of the acceleration sensor.

In one embodiment, the out-of-plane displacement detecting unit 53 includes a first out-of-plane detecting plate and a second out-of-plane detecting plate, where the first out-of-plane detecting plate and the second out-of-plane detecting plate are opposite and form a capacitive plate structure, and the first out-of-plane detecting plate is located on the base or the cavity cover, and the second out-of-plane detecting plate is located on the first seesaw unit 51 and the second seesaw unit 52.

Example 2

The present embodiment provides another acceleration sensor having substantially the same structure as that of embodiment 1, and only different parts will be described below.

Referring to fig. 6 to 9 and fig. 24 and 26, the second acceleration detection unit 6 is configured to detect acceleration in the in-plane X-axis direction.

Referring to fig. 24, the second acceleration detection unit 6 includes a first mass 611 and a first capacitance set; the first mass block 611 is symmetrically provided with first mounting grooves 612, and each first mounting groove 612 is internally provided with a first capacitor bank;

The first capacitor group includes a first fixed electrode 615 and a first movable electrode 616, and a plurality of first fixed electrodes 615 and a plurality of first movable electrodes 616 are each distributed along the in-plane Y-axis direction. The first movable electrodes 616 are disposed at intervals, and each of the first movable electrodes 616 is connected to the first mass 611. The first fixed electrodes 615 are disposed at intervals, and the first fixed electrodes 615 are fixed on the substrate through the second anchor points 12. A first movable electrode 616 is arranged between the two connected first fixed electrodes 615, the first fixed electrode 615 and one first movable electrode 616 form a first differential detection capacitor, and the first fixed electrode 615 and the other first movable electrode 616 form a second differential detection capacitor.

When the first mass block 611 is displaced to the left under the action of the acceleration to the left along the in-plane X-axis, the capacitance interval of the first differential detection capacitor is reduced, the capacitance interval of the second differential detection capacitor is increased, the first differential detection capacitor and the second differential detection capacitor change in proportion to the acceleration to the left along the in-plane X-axis, and the real-time value of the acceleration to the left along the in-plane X-axis can be obtained by detecting the change of the capacitance difference.

Similarly, when the first mass 611 is displaced rightward by the rightward acceleration along the in-plane X-axis, a real-time value of the rightward acceleration along the in-plane X-axis can be obtained by detecting the change in the capacitance value.

Illustratively, the first capacitor bank includes a plurality of sets, and the first fixed electrode 615 of each set of the first capacitor bank is fixed to the substrate by the second anchor 12. The plurality of second anchor points 12 are each adjacent to the first anchor point 11. The anchor point of the fixed electrode for in-plane X-axis detection is also placed near the first anchor point 11 of the motion structure, so that all the detection electrodes and the anchor point of the motion structure are positioned in the center of the structure, and the interference capability of the acceleration sensor for resisting factors such as stress and the like is further improved.

Example 3

The present embodiment provides another acceleration sensor having substantially the same structure as that of embodiment 1, and only different parts will be described below.

Referring to fig. 10 to 14, and also referring to fig. 25, the second acceleration detecting unit 6 is configured to detect acceleration along the in-plane Y-axis direction, the second elastic member 3 is a Y-axis single-degree-of-freedom spring 32 distributed along the in-plane X-axis direction, and the second acceleration detecting unit 6 is fixed to the connecting arm 4 through the Y-axis single-degree-of-freedom spring 32;

the second acceleration detection unit 6 includes a second mass 621 and a second capacitance set; second mounting grooves 622 distributed along the in-plane X-axis direction are formed in the middle of the second mass block 621 at intervals, and a second capacitor group is arranged in each second mounting groove 622;

The second capacitor group includes a second positive fixed electrode 623 and a second negative fixed electrode 624, the second positive fixed electrode 623 and the second negative fixed electrode 624 being distributed along the in-plane X-axis direction; the side of the second positive fixed electrode 623 away from the second negative fixed electrode 624 forms a third differential detection capacitance with the second mass 621, and the side of the second negative fixed electrode 624 away from the second positive fixed electrode 623 forms a fourth differential detection capacitance with the second mass 621.

Referring to fig. 25, when the second mass 621 is displaced upward by the acceleration in the Y-axis direction, the capacitance interval of the third differential detection capacitor decreases, the capacitance interval of the fourth differential detection capacitor increases, the third differential detection capacitor and the fourth differential detection capacitor change in capacitance difference proportional to the acceleration in the Y-axis direction, and a real-time value of the acceleration in the Y-axis direction can be obtained by detecting the change in capacitance difference.

Similarly, when the second mass 621 is displaced downward by the acceleration downward along the Y axis, a real-time value of the acceleration downward along the Y axis can be obtained by detecting a change in the capacitance value.

In the above embodiment, the second acceleration detection unit 6 has a reasonable structural design, and can accurately measure the in-plane Y-axis acceleration.

For example, referring to fig. 16, the Y-axis single degree of freedom spring 32 may be designed in different shapes depending on the specific structure of the acceleration sensor to better enable the detection of the in-plane Y-axis acceleration of the acceleration sensor.

Referring to fig. 26, in another embodiment, the second acceleration detection unit 6 includes a second mass 621 and a second capacitance set; second mounting grooves 622 are symmetrically formed in the second mass block 621, and a second capacitor bank is arranged in each second mounting groove 622;

The second capacitor group includes a second fixed electrode 625 and a second movable electrode 626, and a plurality of second fixed electrodes 625 and a plurality of second movable electrodes 626 are each distributed along the in-plane X-axis direction. The second movable electrodes 626 are disposed at intervals, and the second movable electrodes 626 are connected to the second mass 621. The second fixed electrodes 625 are disposed at intervals, and the second fixed electrodes 625 are fixed on the substrate through the second anchor points 12. A second movable electrode 626 is arranged between the two connected second fixed electrodes 625, the second fixed electrode 625 and one second movable electrode 626 form a third differential detection capacitor, and the second fixed electrode 625 and the other second movable electrode 626 form a fourth differential detection capacitor.

When the second mass block 621 is displaced upward by the acceleration in the Y-axis direction, the capacitance interval of the third differential detection capacitor decreases, the capacitance interval of the fourth differential detection capacitor increases, the third differential detection capacitor and the fourth differential detection capacitor change in capacitance difference proportional to the acceleration in the Y-axis direction, and the real-time value of the acceleration in the Y-axis direction can be obtained by detecting the change in capacitance difference.

Similarly, when the second mass 621 is displaced downward by the acceleration downward along the Y axis, a real-time value of the acceleration downward along the Y axis can be obtained by detecting a change in the capacitance value.

Illustratively, the second capacitor bank includes a plurality of sets, and the second fixed electrode 625 of each set of the second capacitor bank is fixed to the substrate by a second anchor 12. The plurality of second anchor points 12 are each adjacent to the first anchor point 11. The anchor point of the fixed electrode for in-plane Y-axis detection is also placed near the first anchor point 11 of the motion structure, so that all the detection electrodes and the anchor point of the motion structure are positioned in the center of the structure, and the interference capability of the acceleration sensor for resisting factors such as stress and the like is further improved.

Example 4

The present embodiment provides another acceleration sensor having substantially the same structure as that of embodiment 1, and only different parts will be described below.

Referring to fig. 17 to 22, the ring-shaped structure surrounds the outside of the connecting arm 4; the connecting arm 4 is provided with a containing groove 41 for installing the second acceleration detecting unit 6; the first anchor point 11 is located at the center of the connecting arm 4.

In the above embodiment, the structural design of the connecting arm 4 is reasonable, and the second acceleration detecting unit 6 is also convenient to be quickly mounted in the accommodating groove 41, so that the acceleration along the in-plane X-axis direction and/or the in-plane Y-axis direction can be accurately detected.

Alternatively, two of the receiving grooves 41 are symmetrically disposed. This facilitates accurate detection of acceleration in the in-plane X-axis direction and/or in-plane Y-axis direction.

For example, the accommodating groove 41 may be rectangular or polygonal.

Alternatively, one of the second acceleration detecting units 6 is provided in each of the accommodating grooves 41;

One of the second acceleration detection units 6 is configured to detect acceleration in the in-plane X-axis direction; the other of the second acceleration detection units 6 is configured to detect acceleration in the Y-axis direction in the plane.

In the embodiment, the acceleration sensor can detect the acceleration along the in-plane X-axis direction, the acceleration along the in-plane Y-axis direction and the acceleration along the out-of-plane Z-axis direction simultaneously, so that the triaxial accelerometer is formed, the detection range of the acceleration sensor is enlarged, and the use is very convenient.

In the embodiment of the application, the detection masses of the three axes of the acceleration sensor share the same first anchor point 11, and the detection masses of the three axes are separately distributed through frames distributed among the detection masses of the in-plane X axis, the in-plane Y axis and the out-of-plane Z axis, so that cross interference among the axes is avoided.

Illustratively, the second acceleration detection unit 6 for detecting in-plane X-axis acceleration and the second acceleration detection unit 6 for detecting in-plane Y-axis acceleration are located on opposite sides of the anchor point, respectively, so that the structure of the acceleration sensor is optimized.

Note that, the detection mode of the in-plane X-axis direction means that the acceleration sensor is subjected to the acceleration in the in-plane X-axis direction, see fig. 2, 7, and 18; the detection mode in the in-plane Y-axis direction means that the acceleration sensor is subjected to the acceleration in the in-plane Y-axis direction, see fig. 11 and 19; the detection mode of the out-of-plane Z-axis direction means that the acceleration sensor is subjected to the acceleration of the out-of-plane Z-axis direction, see fig. 3, 8, 12 and 20; parasitic modes in the out-of-plane Z-axis direction refer to that the acceleration sensor is subjected to both the acceleration in the out-of-plane Z-axis direction and the angular acceleration in the Y-axis direction, see fig. 4, 9, 13 and 21.

It is to be understood that the above embodiments are merely illustrative of the application of the principles of the present invention, but not in limitation thereof. Various modifications and improvements may be made by those skilled in the art without departing from the spirit and substance of the invention, and are also considered to be within the scope of the invention.

Claims (10)

1. An acceleration sensor, characterized by comprising:

A first acceleration detection unit for detecting acceleration in an out-of-plane Z-axis direction; the first acceleration detection unit comprises a first teeter-totter unit and a second teeter-totter unit, the first teeter-totter unit and the second teeter-totter unit are arranged oppositely, and the first teeter-totter unit and the second teeter-totter unit are enclosed to form an annular structure;

A second acceleration detection unit for detecting acceleration in an in-plane X-axis direction and/or an in-plane Y-axis direction; the annular structure surrounds the outer side of the second acceleration detection unit;

The device comprises a substrate, a connecting arm and a first anchor point, wherein the first anchor point is positioned in the middle of the substrate, and the connecting arm is fixed on the substrate through the first anchor point; the connecting arm is positioned between the first acceleration detection unit and the second acceleration detection unit;

the first acceleration detection unit is connected with the connecting arm through the first elastic piece; the second acceleration detection unit is connected with the connecting arm through the second elastic piece;

The out-of-plane Z-axis direction, the in-plane X-axis direction and the in-plane Y-axis direction are perpendicular to each other.

2. The acceleration sensor of claim 1, characterized in, that the first acceleration detection unit further comprises an out-of-plane displacement detection unit;

The middle part of the connecting arm, which is close to one side of the second acceleration detection unit, is fixed on the first anchor point;

The first seesaw unit is elastically connected with the first end of the connecting arm, and the second seesaw unit is elastically connected with the second end of the connecting arm; the first seesaw units and the second seesaw units are symmetrically distributed along the symmetry axis of the acceleration sensor respectively; the first teeterboard units respectively form two first teeterboard structures on two sides of the symmetry axis, and the two first teeterboard structures rotate along the first rotation axis; the second seesaw units respectively form two second seesaw structures on two sides of the symmetrical shaft, and the two second seesaw structures rotate along a second rotating shaft; the first rotating shaft and the second rotating shaft are arranged in parallel, and the first rotating shaft and the second rotating shaft are perpendicular to the symmetry axis;

The first seesaw unit and the second seesaw unit are respectively provided with the out-of-plane displacement detection unit.

3. The acceleration sensor of claim 2, wherein a first groove is provided on an outer side of the first seesaw unit, a second groove is provided on an inner side of the second seesaw unit, a portion of the first seesaw unit is embedded in the second groove, and a portion of the second seesaw unit is embedded in the first groove to form a nested structure, and the nested structure is located between the first rotating shaft and the second rotating shaft.

4. An acceleration sensor as claimed in claim 3, further comprising a first and a second proof mass;

Each first seesaw structure comprises a first sub-rotating part and a second sub-rotating part, the first sub-rotating parts and the second sub-rotating parts are respectively positioned at two opposite sides of the first rotating shaft, and a first groove is formed in the outer side of the second sub-rotating parts; each second seesaw structure comprises a third sub-rotating part and a fourth sub-rotating part, wherein the third sub-rotating part and the fourth sub-rotating part are respectively positioned at two opposite sides of the second rotating shaft, and a second groove is formed in the inner side of the third sub-rotating part;

The first detection mass block is located at the first sub-rotating part, the second detection mass block is located at the fourth sub-rotating part, and the first detection mass block and the second detection mass block are symmetrically arranged.

5. The acceleration sensor of claim 4, further comprising a coupling beam extending in a direction perpendicular to the symmetry axis, one end of the coupling beam being connected to the second sub-rotating part, the other end being connected to the third sub-rotating part.

6. The acceleration sensor of claim 1, wherein a second acceleration detecting unit is configured to detect acceleration along an in-plane X-axis direction, the second elastic member is an X-axis single-degree-of-freedom spring distributed along an in-plane Y-axis direction, and the second acceleration detecting unit is fixed to the connecting arm through the X-axis single-degree-of-freedom spring;

The second acceleration detection unit comprises a first mass block and a first capacitor bank; first mounting grooves distributed along the Y-axis direction in the plane are formed in the first mass block at intervals, and a first capacitor group is arranged in each first mounting groove;

the first capacitor group comprises a first positive fixed electrode and a first negative fixed electrode, and the first positive fixed electrode and the first negative fixed electrode are distributed along the Y-axis direction in the plane; one side of the first positive fixed electrode, which is far away from the first negative fixed electrode, and the first mass block form a first differential detection capacitor, and one side of the first negative fixed electrode, which is far away from the first positive fixed electrode, and the first mass block form a second differential detection capacitor.

7. The acceleration sensor of claim 1, wherein a second acceleration detecting unit is configured to detect acceleration along an in-plane Y-axis direction, the second elastic member is a Y-axis single-degree-of-freedom spring distributed along an in-plane X-axis direction, and the second acceleration detecting unit is fixed to the connecting arm through the Y-axis single-degree-of-freedom spring;

The second acceleration detection unit comprises a second mass block and a second capacitor bank; second mounting grooves distributed along the X-axis direction in the plane are formed in the middle of the second mass block at intervals, and a second capacitor group is arranged in each second mounting groove;

The second capacitor group comprises a second positive fixed electrode and a second negative fixed electrode, and the second positive fixed electrode and the second negative fixed electrode are distributed along the X-axis direction in the plane; and one side of the second positive fixed electrode, which is far away from the second negative fixed electrode, and the second mass block form a third differential detection capacitor, and one side of the second negative fixed electrode, which is far away from the second positive fixed electrode, and the second mass block form a fourth differential detection capacitor.

8. The acceleration sensor of claim 1, characterized in, that the ring structure surrounds the outside of the connecting arm;

the connecting arm is provided with a containing groove for installing the second acceleration detection unit;

the first anchor point is located at the center of the connecting arm.

9. The acceleration sensor of claim 8, wherein two of the receiving grooves are symmetrically arranged.

10. The acceleration sensor of claim 9, wherein one of the second acceleration detecting units is provided in each of the accommodation grooves;

The second acceleration detection unit is used for detecting the acceleration in the X-axis direction in the plane; the other second acceleration detection unit is used for detecting acceleration in the Y-axis direction in the plane.