A MEMS single-axis gyroscope

Abstract

The present invention provides a MEMS single-axis gyroscope, which includes an anchor unit, a sensing unit elastically connected to the anchor unit, and a driving decoupling structure elastically connected to the anchor unit and the sensing unit; the sensing unit includes a plurality of mass blocks arranged side by side and rocker connectors connected between every two adjacent mass blocks; the connection points of the rocker connectors with the adjacent two mass blocks are located on the same side of the center line connecting the two mass blocks. The MEMS single-axis gyroscope of the present invention can perform differential detection, resist the interference of external electrical and mechanical noises, and improve the signal-to-noise ratio of the device; by adjusting the rocker connectors between the two mass blocks, the vector displacements of the respective mass blocks are zero, the torque balance of the mass blocks can be achieved, and the impacts of external linear acceleration and angular acceleration can be immunized; compared with the traditional butterfly-wing structure single-axis gyroscope, in this solution, the respective mass blocks are strongly coupled through the rocker connectors, ensuring the displacement ratio of the respective mass blocks and improving the redundancy of the device to the process.

Description

Technical Field

[0001] The present invention relates to the technical field of gyroscopes, and in particular to a MEMS single-axis gyroscope.

Background Art

[0002] A gyroscope is a device used to sense and maintain direction, which is used to detect the rotational angular velocity when a physical quantity deflects and tilts. It is mostly used in systems such as navigation and positioning. Common examples include mobile phone GPS positioning navigation, motion-sensing game consoles, satellite gyroscope positioning, etc.

[0003] Patent document 201180019449.7 discloses a MEMS structure for an angular velocity sensor, which adopts a double-mass butterfly-wing structure form. The MEMS structure is symmetric about two axes in the horizontal plane. The base of the structure has the function of releasing stress, and the drive loop and detection loop adopt closed-loop control. The butterfly-wing structure is a structure of two vibrating wheel-type structures that are coupled in vibration. The gyroscope uses the negative stiffness effect to tune the drive mode and detection mode, and at the same time compensates for the orthogonal error to solve the problem of the torsional vibration coupling of the resonator to the outside. It has high precision, low noise, high stability, and has high anti-impact and anti-vibration capabilities; however, in this structure form, the coupling between the double-mass structures is weak, the displacement ratio of the mass blocks cannot be guaranteed, and it is easily affected by acceleration impacts, which affects the measurement accuracy.

[0004] Therefore, it is necessary to improve the related technology and provide a MEMS single-axis gyroscope with strong coupling between the mass structures and capable of ensuring the displacement ratio of the mass blocks.

Summary of the Invention

[0005] The purpose of the present invention is to provide a MEMS single-axis gyroscope to solve the problems of weak coupling between the gyro mass structures and the inability to guarantee the displacement ratio of the mass blocks in the related technology.

[0006] The technical solution of the present invention is as follows: A MEMS single-axis gyroscope includes an anchor unit, a sensing unit elastically connected to the anchor unit, and a drive decoupling structure elastically connected to the anchor unit and the sensing unit;

[0007] The sensing unit includes a plurality of mass blocks arranged side by side and rocker connectors connected between every two adjacent mass blocks; the plurality of mass blocks are symmetrically arranged with respect to the line connecting their respective centers. Each mass block includes a main body with a receiving groove formed therein and an elastic structure connected to the main body and located in the receiving groove. The end of the elastic structure away from the main body is connected to the anchor unit; the connection part of the rocker connector and the two mass blocks is located on the same side of the line connecting the centers of the two mass blocks, and the rocker connector is elastically connected to the anchor unit.

[0008] Further, the elastic structure includes a first torsion beam and a second torsion beam that intersect perpendicularly, and the intersection of the first torsion beam and the second torsion beam is located at the center of the mass block. The anchor unit includes a central anchor connected to the intersection.

[0009] Further, the rocker connecting member includes an elastic rocker with both ends respectively connected to the main bodies of the adjacent two mass blocks, and a support beam cross-connected to the elastic rocker. The anchor unit further includes rocker anchors connected to both ends of the support beam.

[0010] Further, the connection of one end of the elastic rocker to the main body of one mass block is close to the end of the one mass block, and the connection of the other end of the elastic rocker to the main body of the other mass block is far from the end of the other mass block.

[0011] Further, three or more mass blocks are arranged side by side, and the rocker connecting members respectively connected between each mass block and the adjacent mass blocks on both sides are symmetrically distributed with respect to the mirror image of the mass block.

[0012] Further, the rocker connecting members are symmetrically distributed with respect to the mirror image of the connection line of the centers of the multiple mass blocks.

[0013] Further, the drive decoupling structure includes two drive decoupling members respectively arranged at both ends of the multiple mass blocks, coupling beams connected between the drive decoupling members and the corresponding ends of the mass blocks arranged at intervals, and an elastic anchor beam group connected to the drive decoupling members; the anchor unit further includes an anchor beam anchor point group connected to the elastic anchor beam group; the drive decoupling members extend along a direction parallel to the connection line of the midpoints of the multiple mass blocks; the coupling beams are located in the gap between the drive decoupling members and the mass blocks and extend along a direction parallel to the connection line of the midpoints of the multiple mass blocks.

[0014] Further, the elastic anchor beam group includes a plurality of first elastic anchor beams vertically connected to both ends of each drive decoupling member, one end of each first elastic anchor beam is connected to the drive decoupling member, and the other end extends away from the drive decoupling member; the anchor beam anchor point group includes first anchor beam anchor points connected to the ends of each first elastic anchor beam away from the drive decoupling member.

[0015] Further, the elastic anchor beam group further includes a plurality of second elastic anchor beams vertically connected to the middle of each drive decoupling member, one end of each second elastic anchor beam is connected to the drive decoupling member, and the other end is away from the drive decoupling member; the anchor beam anchor point group further includes second anchor beam anchor points connected to the ends of each second elastic anchor beam away from the drive decoupling member.

[0016] Further, the MEMS single-axis gyroscope further includes a first transducer connected to the drive decoupling structure, and the first transducer includes any one or a combination of any multiple of a capacitive transducer, an inductive transducer, a thermoelectric transducer, and a piezoelectric transducer.

[0017] Further, the first transducer includes a positive drive electrode and a negative drive electrode that are respectively arranged in parallel outside the drive decoupling member.

[0018] Further, the MEMS single-axis gyroscope further includes a second transducer disposed above or below the plurality of mass blocks in the out-of-plane direction; the second transducer includes any one or a combination of any multiple of a capacitive transducer, an inductive transducer, a thermoelectric transducer, and a piezoelectric transducer.

[0019] The principle of the present invention is as follows:

[0020] Each mass block is respectively connected to the anchor unit through an elastic structure, so that the mass block can rotate in the plane and swing out of the plane; two adjacent mass blocks are coupled to each other through a rocker connecting member, so that the in-plane rotation and out-of-plane swing directions of the two adjacent mass blocks are opposite; the MEMS single-axis gyroscope of the present invention has two vibration modes. In the first mode, the mass block rotates in the plane, which is called the drive mode. In this mode, due to the action of the rocker connecting member, the rotation directions of two adjacent mass blocks are opposite; when the gyroscope is subjected to an external angular velocity ω perpendicular to the rotation direction in the plane, according to the Coriolis principle, the angular velocity ω will generate a Coriolis force orthogonal to the in-plane direction, and the mass block swings out of the plane under the action of this Coriolis force, and this mode is called the detection mode; since the movement directions of both ends of each mass block are opposite in the drive mode, the vibration directions of both ends are opposite in the detection mode; further, since the rotation directions of two adjacent mass blocks are opposite, the vibration directions of the same ends of two adjacent mass blocks are opposite in the detection mode. Based on this, each mass block and two adjacent mass blocks of this MEMS gyroscope can realize differential detection of the external angular velocity ω.

[0021] The beneficial effects of the present invention are as follows: Each mass block and two adjacent mass blocks can perform differential detection, which can resist the interference of external electrical and mechanical noises and improve the signal-to-noise ratio of the device; by adjusting the rocker connecting member between the two mass blocks, the vector displacement of each mass block is zero, which can achieve the moment balance of the mass block and immunize the impact of external linear acceleration and angular acceleration; compared with the traditional single-axis gyroscope with a butterfly wing structure, in this solution, each mass block is strongly coupled through a rocker connecting member, and on the premise of the existence of processing errors, the displacement ratio of each mass block is guaranteed, improving the redundancy of the device to the process.

Description of the Drawings

[0022] Figure 1 It is a top view structural schematic diagram of the MEMS single-axis gyroscope in the embodiment of the present invention;

[0023] Figure 2 is Figure 1 an enlarged view of part a in

[0024] Figure 3 a schematic diagram of the state of the MEMS single-axis gyro in the driving mode in the embodiment of the present invention;

[0025] Figure 4 a schematic diagram of the state of the MEMS single-axis gyro in the detection mode in the embodiment of the present invention.

Specific Embodiment

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0027] As Figure 1 shown, the MEMS single-axis gyro in the embodiment of the present invention includes an anchor unit 1, a sensing unit 2 elastically connected to the anchor unit 1, and a driving decoupling structure 3 elastically connected to the anchor unit 1 and the sensing unit 2; characterized in that,

[0028] The sensing unit 2 includes a plurality of mass blocks 21 arranged side by side, and rocker connectors 22 connected between every two adjacent mass blocks 21; the plurality of mass blocks 21 are symmetrically arranged with respect to the line connecting their respective centers, and each mass block 21 includes a main body 211 having a receiving groove 212 formed therein and an elastic structure 213 connected to the main body 211 and located in the receiving groove 212, and the end of the elastic structure 213 away from the main body 211 is connected to the anchor unit 1; the connection points of the rocker connectors 22 with the two mass blocks 21 are located on the same side of the line connecting the centers of the two mass blocks 21, and the rocker connectors 22 are elastically connected to the anchor unit 1.

[0029] In this embodiment, as Figure 3 shown, in the driving mode, the mass blocks 21 rotate in the plane, the ends of the mass blocks 21 move in a direction parallel to the line connecting the centers of the respective mass blocks 21, and the movement directions of the two ends of the same mass block 21 are opposite; due to the action of the rocker connectors 22, the rotation directions of two adjacent mass blocks 21 are opposite, and therefore, the movement directions of the same ends of two adjacent mass blocks 21 are opposite; Figure 3Figure 0 shows a way of the moving directions of three mass blocks 21 in the driving mode. When the gyroscope is subjected to an external angular velocity ω in the plane and perpendicular to the line connecting the centers of the mass blocks 21, according to the Coriolis principle, the angular velocity ω will generate a Coriolis force orthogonal to the in-plane direction. The mass blocks 21 swing out of the plane under the action of this Coriolis force. Since the moving directions of the two ends of the same mass block 21 are opposite in the driving mode, the vibration directions of the two ends of the mass block 21 are opposite in the detection mode. Further, since the rotation directions of two adjacent mass blocks 21 are opposite, the vibration directions of the same ends of two adjacent mass blocks 21 are opposite in the detection mode. Based on this, each mass block 21 and two adjacent mass blocks 21 of the gyroscope can achieve differential detection of the external angular velocity ω. Figure 4 Figure 0 shows the three mass blocks 21 Figure 3 in the moving directions in the detection mode excited by the angular velocity ω from the driving mode in Figure 0.

[0030] In this embodiment, as Figure 1 shown in Figure 0, the elastic structure 213 includes a first torsion beam 2131 and a second torsion beam 2132 that cross each other perpendicularly. The intersection of the first torsion beam 2131 and the second torsion beam 2132 is located at the center of the mass block 21. The anchor unit 1 includes a central anchor 11 connected to the intersection.

[0031] In this embodiment, as Figure 1 shown in Figure 0, the rocker connector 22 includes an elastic rocker 221 with two ends respectively connected to the main bodies 211 of two adjacent mass blocks 21, and a support beam 222 cross-connected to the elastic rocker 221. The anchor unit 1 further includes rocker anchors 12 connected to both ends of the support beam 222. The connection of one end of the elastic rocker 221 to the main body 211 of a mass block 21 is close to the end of the mass block 21, and the connection of the other end of the elastic rocker 221 to the main body 211 of another mass block 21 is far from the end of the other mass block 21. By adjusting the connection position of the elastic rocker 221 and the mass block 21 and / or adjusting the position of the connection between the support beam 222 and the elastic rocker 221 to adjust the ratio of the support beam 222 dividing the elastic rocker 221, the total vector displacement of multiple mass blocks 21 can be made 0, the moment balance of the mass blocks 21 can be achieved, and the impact of external linear acceleration and angular acceleration can be immunized. In some embodiments, the ratio of the support beam 222 dividing the elastic rocker 221 is 1:1, that is, the intersection of the support beam 222 and the elastic rocker 221 is equidistant from the connections of the two ends of the elastic rocker 221 to the two mass blocks 21 respectively. In some other embodiments, the ratio of the support beam 222 dividing the elastic rocker 221 is 2:1. In some other embodiments, the ratio of the support beam 222 dividing the elastic rocker 221 is greater than 2:1.

[0032] In this embodiment, as Figure 1As shown, three mass blocks 21 are arranged side by side. The rocker connecting member 22 is symmetrically distributed with respect to the middle mass block 21 in a mirror image manner and is also symmetrically distributed with respect to the line connecting the centers of the three mass blocks 21. In this embodiment, by adjusting the connection position of the elastic rocker 221 and the mass block 21, and / or the position of the elastic rocker 221 and the support beam 222, the vector displacement of the middle mass block 21 can be made twice that of the vector displacements of the two side mass blocks 21, achieving moment balance of the three mass blocks 21.

[0033] In this embodiment, as Figure 1 shown, the drive decoupling structure 3 includes two drive decoupling members 31 respectively arranged at both ends of the three mass blocks 21, a coupling beam 32 connected between the drive decoupling member 31 and the corresponding end of each alternately arranged mass block 21, and an elastic anchor beam group 33 connected to the drive decoupling member 31. The anchor point unit 1 includes an anchor beam anchor point group 13 connected to the elastic anchor beam group 33. In this embodiment, as Figure 2 shown, the drive decoupling member 31 extends along a direction parallel to the line connecting the midpoints of the multiple mass blocks 21. In this embodiment, two coupling beams 32 are provided, which are respectively connected to the corresponding ends of the two outer mass blocks 21. The coupling beam 32 is located in the gap between the drive decoupling member 31 and the mass block 21 and extends along a direction parallel to the line connecting the midpoints of the three mass blocks 21. The drive decoupling member 31 and the coupling beam 32 have a large stiffness in the plane direction parallel to the line connecting the midpoints of the three mass blocks 21. Therefore, in the drive mode, the drive decoupling member 31 and the coupling beam 32 are coupled with the mass block 21, and can drive the corresponding end of the mass block 21 to move along a direction parallel to the line connecting the midpoints of the three mass blocks 21. The drive decoupling member 31 has a large stiffness in the out-of-plane direction, and the coupling beam 32 has a small stiffness in the out-of-plane direction. Therefore, in the detection mode, the coupling beam 32 swings out of the plane with the mass block 21, while the drive decoupling member 31 remains stationary, achieving decoupling of the drive decoupling member 31 and the mass block 21.

[0034] In this embodiment, as Figure 1 shown, the elastic anchor beam group 33 includes a plurality of first elastic anchor beams 331 vertically connected to both ends of each drive decoupling member 31, and the first elastic anchor beams 331 connected to the two drive decoupling members 31 are symmetrically distributed with respect to the line connecting the centers of the three mass blocks 21 in a mirror image manner. One end of each first elastic anchor beam 331 is connected to the drive decoupling member 31, and the other end extends away from the drive decoupling member 31. The anchor beam anchor point group 13 includes a first anchor beam anchor point 131 connected to the end of each first elastic anchor beam 331 away from the drive decoupling member 31. In this embodiment, two first elastic anchor beams 331 are respectively connected to both ends of each drive decoupling member 31, and the two first elastic anchor beams 331 at each end are respectively located on both sides of the drive decoupling member 31.

[0035] The elastic anchor beam group 33 further includes a plurality of second elastic anchor beams 332 vertically connected to the middle of each drive decoupling member 31, and the second elastic anchor beams 332 connected to the two drive decoupling members 31 are symmetrically distributed with respect to the connection line of the centers of the three mass blocks 21; one end of each second elastic anchor beam 332 is connected to the drive decoupling member 31, and the other end is away from the drive decoupling member 31; the anchor beam anchor point group 13 further includes a second anchor beam anchor point 132 connected to the end of each second elastic anchor beam 332 away from the drive decoupling member 31; in this embodiment, as Figure 1 shown, two second elastic anchor beams 332 are connected to the middle of each of the two drive decoupling members 31, and the two second elastic anchor beams 332 connected to each drive decoupling member 31 are respectively located on both sides of the drive decoupling member 31; in this embodiment, the extending directions of the first elastic anchor beam 331 and the second elastic anchor beam 332 are perpendicular to the moving direction of the drive decoupling structure 3 in the drive mode, so the first elastic anchor beam 331 and the second elastic anchor beam 332 have a smaller stiffness in the drive direction; in the drive mode, the drive decoupling structure 3 is coupled with the first elastic anchor beam 331 and the second elastic anchor beam 332, and the first elastic anchor beam 331 and the second elastic anchor beam 332 move along the direction parallel to the connection line of the midpoints of the plurality of mass blocks 21.

[0036] In this embodiment, as Figure 1 shown, the MEMS single-axis gyroscope further includes a first transducer 4 connected to the drive decoupling structure 3, and the first transducer 4 includes any one or any combination of a capacitive transducer, an inductive transducer, a thermoelectric transducer, and a piezoelectric transducer; in this embodiment, the first transducer 4 includes a positive drive electrode 41 and a negative drive electrode 42 respectively arranged in parallel on the outside of the drive decoupling member 31.

[0037] In this embodiment, as Figure 1 shown, the MEMS single-axis gyroscope further includes a second transducer 5 arranged out of the plane above or below the plurality of mass blocks 21; in this embodiment, the second transducer 5 includes one second transducer 51 above each end of each mass block 21; the second transducer 5 includes any one or any combination of a capacitive transducer, an inductive transducer, a thermoelectric transducer, and a piezoelectric transducer.

[0038] The above are only the embodiments of the present invention. It should be noted here that for those of ordinary skill in the art, improvements can be made without departing from the inventive concept of the present invention, but these all belong to the protection scope of the present invention.

Claims

1. A MEMS single-axis gyroscope, comprising an anchor unit, a sensing unit elastically connected to the anchor unit, and a drive decoupling structure elastically connected to the anchor unit and the sensing unit; characterized in that, The sensing unit includes a plurality of mass blocks arranged side by side and rocker connectors connected between every two adjacent mass blocks; the plurality of mass blocks are axially symmetrically arranged with the connection line of their respective centers as the axis, and more than three mass blocks are arranged side by side. Each mass block includes a main body with a receiving groove formed therein and an elastic structure connected to the main body and located within the receiving groove. The end of the elastic structure away from the main body is connected to the anchor unit; the connection of the rocker connector to the two adjacent mass blocks is located on the same side of the connection line of the centers of the two mass blocks, and the rocker connector is elastically connected to the anchor unit; The drive decoupling structure includes two drive decoupling members respectively arranged at both ends of the plurality of mass blocks, coupling beams connected between the drive decoupling members and corresponding ends of the mass blocks arranged at intervals, and an elastic anchor beam group connected to the drive decoupling members; the anchor unit further includes an anchor beam anchor point group connected to the elastic anchor beam group; the drive decoupling member extends in a direction parallel to the connection line of the midpoints of the plurality of mass blocks; the coupling beam is located within the gap between the drive decoupling member and the mass block and extends in a direction parallel to the connection line of the midpoints of the plurality of mass blocks.

2. The MEMS single-axis gyroscope according to claim 1, characterized in that: The elastic structure includes a first torsion beam and a second torsion beam that intersect perpendicularly. The intersection of the first torsion beam and the second torsion beam is located at the center of the mass block. The anchor unit includes a center anchor point connected to the intersection.

3. The MEMS single-axis gyroscope according to claim 1, characterized in that: The rocker connector includes an elastic rocker with both ends respectively connected to the main bodies of the two adjacent mass blocks and a support beam cross-connected to the elastic rocker. The anchor unit further includes rocker anchor points connected to both ends of the support beam.

4. The MEMS single-axis gyroscope according to claim 3, characterized in that: The connection of one end of the elastic rocker to the main body of a mass block is close to the end of the mass block, and the connection of the other end of the elastic rocker to the main body of another mass block is far from the end of the other mass block.

5. The MEMS single-axis gyroscope according to claim 1, characterized in that: The rocker connectors respectively connected between each mass block and the adjacent mass blocks on both sides are mirror-symmetrically distributed with respect to the mass block.

6. The MEMS single-axis gyroscope according to claim 1, characterized in that: The rocker connectors are mirror-symmetrically distributed with respect to the connection line of the centers of the plurality of mass blocks.

7. The MEMS single-axis gyroscope according to claim 1, characterized in that: The elastic anchor beam group includes a plurality of first elastic anchor beams vertically connected to both ends of each drive decoupling member. One end of each first elastic anchor beam is connected to the drive decoupling member, and the other end extends away from the drive decoupling member; the anchor beam anchor point group includes first anchor beam anchor points connected to the ends of each first elastic anchor beam away from the drive decoupling member.

8. The MEMS single-axis gyroscope according to claim 7, characterized in that: The elastic anchor beam group further includes a plurality of second elastic anchor beams vertically connected to the middle of each drive decoupling member. One end of each second elastic anchor beam is connected to the drive decoupling member, and the other end is away from the drive decoupling member; the anchor beam anchor point group further includes second anchor beam anchor points connected to the ends of each second elastic anchor beam away from the drive decoupling member.

9. The MEMS single-axis gyroscope according to claim 1, characterized in that: The MEMS uniaxial gyroscope further includes a first transducer connected to the drive decoupling structure and a second transducer disposed above or below the plurality of mass blocks in the out-of-plane direction; the first transducer includes a positive drive electrode and a negative drive electrode that are respectively disposed in parallel on the outer side of the drive decoupling member.

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