Motion decoupling MEMS gyroscope sensor structure

Abstract

The invention provides a motion decoupling MEMS (Micro Electro Mechanical System) gyroscope sensor structure, which solves the adverse effects caused by the fact that the driving mass bodies and the detection mass bodies are in motion coupling and the coupling between the driving mass bodies is in a rotating mode in the existing gyroscope sensor structure. The involved mass body is connected with the driving mass body and the detection mass body through the combined decoupling beam, when an angular velocity signal is input, the involved mass body drives the detection mass body to move, the detection shaft electrode performs stable detection, closed-loop control is achieved through a force feedback control signal, transmission of Coriolis force is achieved when the angular velocity is input, and the detection precision is improved. And the detection mass body is driven to move to measure the angular velocity. According to the combined decoupling beam structure, the purpose that the driving mass body drives the involved mass body to achieve driving motion is achieved, meanwhile, the influence on the detection mass body is avoided, and the good motion decoupling effect is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of inertial sensors, and in particular relates to a motion decoupled MEMS gyroscope sensor structure. Background Art

[0002] The MEMS gyroscope sensor structure is the core part of the MEMS gyroscope, and serves as the execution structure of the MEMS gyroscope to measure the angular velocity signal of the carrier. Under the control of the control circuit, when the angular velocity signal acts, the internal structure of the MEMS gyroscope sensor structure will change position under the action of the Coriolis force, and then the angular velocity signal will be calculated by the control circuit.

[0003] In existing MEMS gyroscopes, there is a certain amount of motion coupling between the driving mass body and the detection mass body (also called sensitive mass body) of the gyroscope sensor structure, which causes the movement of the driving axis to be superimposed on the detection axis, resulting in a large error signal. At the same time, the coupling between the driving mass bodies is in the form of rotation, which will cause a large energy loss and reduce the driving stability. The influence of multiple unfavorable factors makes it difficult to improve the accuracy of MEMS gyroscopes, and their anti-interference ability is poor, which limits their use scenarios.

[0004] In view of this, it is necessary to optimize the MEMS gyroscope sensor structure. Summary of the invention

[0005] The purpose of the present invention is to solve the adverse effects of the existing gyroscope sensor structure caused by the motion coupling between the driving mass body and the detection mass body and the rotational coupling between the driving mass bodies, and to provide a MEMS gyroscope sensor structure with motion decoupling, aiming to eliminate the influence of the driving shaft movement on the detection axis, reduce errors, reduce energy consumption, and improve driving stability, thereby improving the accuracy and anti-interference ability of the MEMS gyroscope and expanding its application scenarios.

[0006] The concept of the present invention:

[0007] In response to the influence of the motion coupling between the driving mass body and the detection mass body and the coupling between the driving mass bodies in the form of rotation mentioned in the background technology, the researchers of the present invention can eliminate the motion coupling between the driving mass body and the detection mass body, and change the coupling mode between the driving mass bodies at the same time by changing the coupling mode between the driving mass body and the detection mass body, and at the same time changing the coupling mode between the driving mass bodies; to this end, the present invention introduces a combined decoupling beam to connect the involved mass body and the driving mass body and the detection mass body, so as to realize the transmission of Coriolis force when angular velocity is input, and at the same time eliminate the mutual influence between the movement of the driving shaft and the movement of the detection shaft, so that the driving shaft and the detection shaft can move independently, effectively improving the accuracy and anti-interference ability of the gyroscope.

[0008] To achieve the above purpose, the technical solution provided by the present invention is:

[0009] A motion decoupled MEMS gyroscope sensor structure, which is special in that:

[0010] It includes four groups of mass units, four T-shaped motion coupling beams and one cross-shaped motion coupling beam;

[0011] The four groups of mass units are distributed in four corners and arranged symmetrically in pairs; the outer sides of two adjacent groups of mass units are fixedly connected by a T-shaped motion coupling beam, and the center position of the four groups of mass units after combination is fixedly connected by a cross-shaped motion coupling beam;

[0012] Each group of mass units includes an involved mass, two driving mass bodies, two detection mass bodies, a driving mass driving comb structure, a driving mass detection comb structure, a detection mass detection comb structure and a detection mass feedback comb structure;

[0013] A rectangular space is opened at each of the four directions of the involved mass body, and the four rectangular spaces are arranged in a cross shape in pairs;

[0014] A driving mass body is arranged in each of a pair of oppositely arranged rectangular spaces, and the two driving mass bodies are connected to the involved mass body through a combined decoupling beam and are symmetrical relative to the center of the involved mass body; a driving mass driving comb structure is installed on one of the driving mass bodies, and a driving mass detection comb structure is installed on the other driving mass body; the driving comb structure matches the fixed comb structure to form a capacitor pair, and the driving comb capacitor pair adopts a sliding film capacitor structure, the comb spacing size is 1-5um, and the comb teeth are equidistantly distributed;

[0015] Another pair of relatively arranged rectangular spaces are each provided with a detection mass body, and the two detection mass bodies are connected to the involved mass body through a combined decoupling beam and are symmetrical relative to the center of the involved mass body; a detection mass detection comb tooth structure is installed on one of the detection mass bodies, and a detection mass feedback comb tooth structure is installed on the other detection mass body; the detection comb tooth structure is matched with the fixed comb tooth structure to form a capacitor pair, and the detection comb tooth capacitor pair adopts a pressed film capacitor structure, the comb tooth small pitch size is 1-5um, and the large pitch size is 2-5 times the small pitch size;

[0016] The combined decoupling beam comprises a Y-shaped beam, a decoupling mass body and a decoupling beam connected in sequence; wherein the end of the Y-shaped beam is connected to the driving mass body or the detection mass body, and the end of the decoupling beam is connected to the involved mass body;

[0017] The four T-shaped motion coupling beams and one cross-shaped motion coupling beam assemble the four groups of mass body units together through the decoupling mass bodies in each combined decoupling beam, and the motion coupling beam connects the decoupling mass bodies, so that the motion coupling between the decoupling mass bodies is linear movement; after the four groups of mass body units are assembled, the directions of the center lines of the two driving mass bodies in each group of mass body units are parallel to each other and parallel to the direction of one arm in the cross-shaped motion coupling beam; the directions of the center lines of the two detection mass bodies in each group of mass body units are parallel to each other and parallel to the direction of the other arm in the cross center beam;

[0018] The driving mass body, the detection mass body and the involved mass body all have the freedom to move in two directions, that is, they can all move along two axes.

[0019] Furthermore, the two ends of the horizontal arm of the T-shaped motion coupling beam are fixedly connected to two adjacent groups of mass body units, and the two side surfaces of the vertical arm of the T-shaped beam are fixedly connected to the two adjacent groups of mass body units through connecting protrusions;

[0020] The two side surfaces of each of the four arms of the cross-shaped motion coupling beam are fixedly connected to a group of mass body units through connecting protrusions, and the four arms of the cross-shaped motion coupling beam are flush with the vertical arms of the four T-shaped motion beams respectively.

[0021] Further, the driving mass body is supported by a plurality of sets of symmetrically distributed driving beams;

[0022] Multiple groups of driving beams are evenly distributed around the driving mass body, and the structural dimensions are consistent, ensuring that the rigidity of each axial direction of the driving beam is consistent;

[0023] One end of the driving beam is fixed on the substrate or the outer frame, and the other end provides supporting force for the driving mass body.

[0024] Furthermore, the driving beam is a combined beam structure or a single cantilever beam structure, and the relationship between the beams is parallel, that is, multiple groups of driving beams are combined in parallel, which can provide the driving mass body with freedom to move in two directions; and the combination of a single driving beam is series or parallel.

[0025] Further, the detection mass body is supported by multiple groups of symmetrically distributed detection beams;

[0026] Multiple groups of detection beams are evenly distributed around the detection mass body, and the structural dimensions are consistent to ensure that the stiffness of each axial direction of the detection beam is consistent;

[0027] Among them, one end of the detection beam is fixed on the substrate or the outer frame, and the other end provides supporting force for the detection mass body.

[0028] Furthermore, the detection beam is a combined beam structure or a single cantilever beam structure, and the relationship between the beams is parallel, that is, multiple groups of detection beams are combined in parallel, which can provide the detection mass with freedom to move in two directions; and the combination of a single detection beam is series or parallel.

[0029] Further, the decoupling beam is a single cantilever beam or a folded beam;

[0030] The T-shaped motion coupling beam and the cross-shaped motion coupling beam are both composite beams, including a single cantilever beam and a folded beam;

[0031] The width of the decoupling beam is 2-10um, and the length is 20-50 times the width;

[0032] The width of the Y-shaped beam structure is 2-10um, and the length is 2-5 times of the width.

[0033] Furthermore, the width of the driving beam is 2-10 um, and the length is 50-100 times the width;

[0034] The detection beam has a width of 2-10 um and a length of 50-100 times the width.

[0035] At the same time, the present invention also provides a MEMS gyroscope using the above-mentioned motion decoupled MEMS gyroscope sensor structure as a core component.

[0036] Principle of the present invention:

[0037] The sensor structure driving mass body is stably driven by the driving shaft electrode, and drives the implicated mass body to move through the combined decoupling beam, making it in differential high-frequency oscillation. When there is an angular velocity signal input, the implicated mass body generates orthogonal axis motion under the action of the Coriolis force, and drives the detection mass body to move along the orthogonal axis. The orthogonal motion of the detection mass body causes the capacitance value of the detection comb capacitance pair to change, and the detection shaft electrode pair stably detects the capacitance change and forms a feedback voltage through the control circuit, which is applied to the detection shaft feedback electrode pair, so that the detection mass body is in a closed-loop control state. The T-type motion coupling beam and the cross-type motion coupling beam connect the decoupling mass bodies on different combined decoupling beams, so that the coupling process between the driving motion presents linear movement, greatly reducing the interference to the driving motion and improving the driving stability. The combined decoupling beam connects the implicated mass body with the driving mass body and the detection mass body to realize the transmission of the Coriolis force when the angular velocity is input, and at the same time eliminates the mutual influence between the axis motion and the detection axis motion, so that the driving axis and the detection axis move independently, effectively improving the accuracy and anti-interference ability of the gyroscope.

[0038] Advantages of the present invention:

[0039] 1. In the present invention, the involved mass body connects the driving mass body and the detection mass body through a combined decoupling beam. When an angular velocity signal is input, the involved mass body drives the detection mass body to move, and the detection axis electrode stably detects and uses the force feedback control signal to achieve closed-loop control, thereby realizing the transmission of Coriolis force when the angular velocity is input, and driving the detection mass body to move to achieve the measurement of angular velocity. The combined decoupling beam structure not only realizes the purpose of the driving mass body driving the involved mass body to drive the motion, but also avoids the influence on the detection mass body, achieving a good motion decoupling effect. The motion coupling beam pulls the decoupling mass body, so that the motion coupling between the driving mass bodies is in mobile motion rather than rotational motion, which greatly reduces the energy loss of the driving motion coupling and effectively improves the motion stability.

[0040] 2. The sensor structure of the present invention utilizes a combined decoupling beam to achieve complete decoupling of driving motion and detecting motion, and can effectively improve the accuracy and anti-interference capability of the MEMS gyroscope when the MEMS gyroscope control circuit drives differential operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is a schematic diagram of the gyroscope sensor structure;

[0042] Figure 2 Schematic diagram of the drive shaft structure;

[0043] Figure 3 This is a schematic diagram of the detection axis structure;

[0044] Figure 4 It is a schematic diagram of the combined decoupling beam structure;

[0045] Figure 5 It is a schematic diagram of the T-type motion coupling beam structure;

[0046] In the figure: 1-driving mass body, 2-driving beam, 3-involved mass body, 4-combined decoupling beam, 5-detection mass body, 6-detection beam, 7-driving mass driving comb tooth structure, 8-driving mass detection comb tooth structure, 9-detection mass detection comb tooth structure, 10-detection mass feedback comb tooth structure, 11-T-type motion coupling beam, 12-Y-type beam, 13-decoupling mass body, 14-decoupling beam, 15-cross motion coupling beam. DETAILED DESCRIPTION

[0047] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0048] like Figure 1As shown, a motion-decoupled MEMS gyroscope structure includes four groups of mass units, four T-shaped motion coupling beams and a cross-shaped motion coupling beam; the four groups of mass units are distributed at four corners and arranged symmetrically in pairs; the outer sides of two adjacent groups of mass units are fixedly connected by a T-shaped motion coupling beam, and the center position of the four groups of mass units after combination is fixedly connected by a cross-shaped motion coupling beam.

[0049] Each group of mass units includes an involved mass body, two driving mass bodies, two detection mass bodies, a driving mass driving comb structure, a driving mass detection comb structure, a detection mass detection comb structure, and a detection mass feedback comb structure. A rectangular space is opened at each of the four directions of the involved mass body, and the four rectangular spaces are arranged in a cross shape in pairs.

[0050] A driving mass body is arranged in each of a pair of oppositely arranged rectangular spaces, and the two driving mass bodies are symmetrical with respect to the center of the involved mass body. Figure 2 As shown, each driving mass body is connected to the involved mass body through a combined decoupling beam; the driving mass body is supported by multiple groups of symmetrically distributed driving beams; multiple groups of driving beams are evenly distributed around the driving mass body, and the structural dimensions are consistent to ensure that the stiffness of each axial direction of the driving beam is consistent; one end of the driving beam is fixed on the substrate or the outer frame, and the other end provides support force for the driving mass body; the driving beam is a combined beam structure or a single cantilever beam structure, and the relationship between the beams is parallel, which can provide the driving mass body with freedom of movement in two directions; and the combination of a single driving beam is in series or parallel. The width of the driving beam is 2-10um, and the length is 50-100 times the width. The driving mass driving comb tooth structure and the driving mass detection comb tooth structure are symmetrically fixed on the two driving mass bodies, and the specific positions are: the driving mass driving comb tooth structure is fixedly connected to the driving mass body located on the outside, and the driving mass detection comb tooth structure is fixedly connected to the driving mass body located on the inside; in addition, the driving comb tooth structure is matched with the fixed comb tooth structure (not shown in the figure, which is arranged at a position opposite to the driving comb tooth structure and connected to the substrate or anchor point) to form a capacitor pair, and the driving comb tooth capacitor pair adopts a sliding film capacitor structure, the comb tooth spacing size is 1-5um, and the comb teeth are equidistantly distributed.

[0051] Another pair of oppositely arranged rectangular spaces are each provided with a detection mass body, and the two detection mass bodies are symmetrical relative to the center of the involved mass body. Figure 3As shown, each detection mass body is connected to the implicated mass body through a combined decoupling beam; the detection mass body is supported by multiple groups of symmetrically distributed detection beams; multiple groups of detection beams are evenly distributed around the detection mass body, and the structural dimensions are consistent to ensure that the stiffness of each axial direction of the detection beam is consistent; one end of the detection beam is fixed on the substrate or the outer frame, and the other end provides support for the detection mass body; the detection beam is a combined beam structure or a single cantilever beam structure, and the relationship between the beams is parallel, which can provide the detection mass body with freedom of movement in two directions; and the combination of a single detection beam is in series or parallel. The width of the detection beam is 2-10um, and the length is 50-100 times the width. The detection quality detection comb tooth structure and the detection quality feedback comb tooth structure are symmetrically fixed on the two detection quality bodies, and the specific positions are: the detection quality detection comb tooth structure is fixedly connected to the detection quality body located on the outside, and the detection quality feedback comb tooth structure is fixedly connected to the detection quality body located on the inside; in addition, the detection comb tooth structure is matched with a fixed comb tooth structure (not shown in the figure, which is arranged at a position opposite to the detection comb tooth structure and connected to a substrate or an anchor point) to form a capacitor pair, and the detection comb tooth capacitor pair adopts a pressed film capacitor structure, the small pitch size of the comb teeth is 1-5um, and the large pitch size is 2-5 times the small pitch size.

[0052] like Figure 4 As shown, the combined decoupling beam includes a Y-shaped beam, a decoupling mass body and a decoupling beam connected in sequence; wherein the end of the Y-shaped beam is connected to the driving mass body 1 or the detection mass body, and the end of the decoupling beam is connected to the involved mass body; wherein the decoupling beam is a single cantilever beam or a folded beam, the width of the decoupling beam is 2-10um, and the length is 20-50 times the width; the width of the Y-shaped beam structure is 2-10um, and the length is 2-5 times the width.

[0053] Four T-shaped motion coupling beams and one cross-shaped motion coupling beam assemble four groups of mass units together through the decoupling mass bodies in each combined decoupling beam. After the four groups of mass units are assembled, the directions of the center lines of the two driving mass bodies in each group of mass units are parallel to each other and parallel to the direction of one arm in the cross-shaped motion coupling beam; the directions of the center lines of the two detection mass bodies in each group of mass units are parallel to each other and parallel to the direction of the other arm in the cross center beam.

[0054] like Figure 5 As shown, the two ends of the horizontal arm of the T-shaped motion coupling beam are fixedly connected to the two adjacent groups of mass body units, and the two side surfaces of the vertical arm of the T-shaped beam are fixedly connected to the two adjacent groups of mass body units through connecting protrusions; Figure 1 As shown, the two sides of each of the four arms of the cross-shaped motion coupling beam are fixedly connected to a group of mass units through connecting protrusions, and the four arms of the cross-shaped motion coupling beam are flush with the vertical arms of the four T-shaped motion beams. The two types of motion coupling beams are composite beams, including single cantilever beams and folded beams.

[0055] Through the above design, the driving mass body, the detection mass body and the involved mass body all have the freedom to move in two directions, that is, they can all move along two axes.

[0056] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be included in the protection scope of the present invention.

Claims

1. A motion decoupled MEMS gyroscope sensor structure, characterized in that: It includes four groups of mass units, four T-shaped motion coupling beams and one cross-shaped motion coupling beam; The four groups of mass units are distributed in four corners and arranged symmetrically in pairs; the outer sides of two adjacent groups of mass units are fixedly connected by a T-shaped motion coupling beam, and the center position of the four groups of mass units after combination is fixedly connected by a cross-shaped motion coupling beam; Each group of mass units includes an involved mass, two driving mass bodies, two detection mass bodies, a driving mass driving comb structure, a driving mass detection comb structure, a detection mass detection comb structure and a detection mass feedback comb structure; A rectangular space is opened at each of the four directions of the involved mass body, and the four rectangular spaces are arranged in a cross shape in pairs; A pair of oppositely arranged rectangular spaces are both provided with driving mass bodies, and the two driving mass bodies are connected to the involved mass body through a combined decoupling beam and are symmetrical relative to the center of the involved mass body; A driving mass driving comb structure is installed on one of the driving mass bodies, and a driving mass detection comb structure is installed on the other driving mass body; Another pair of relatively arranged rectangular spaces are both provided with detection mass bodies, the two detection mass bodies are connected to the involved mass body through a combined decoupling beam, and are symmetrical relative to the center of the involved mass body; a detection mass detection comb structure is installed on one of the detection mass bodies, and a detection mass feedback comb structure is installed on the other detection mass body; The combined decoupling beam comprises a Y-shaped beam, a decoupling mass body and a decoupling beam connected in sequence; wherein the end of the Y-shaped beam is connected to the driving mass body or the detection mass body, and the end of the decoupling beam is connected to the involved mass body; The four T-shaped motion coupling beams and one cross-shaped motion coupling beam assemble four groups of mass body units together through the decoupling mass bodies in each combined decoupling beam; after the four groups of mass body units are assembled, the directions of the center lines of the two driving mass bodies in each group of mass body units are parallel to each other and parallel to the direction of one arm in the cross-shaped motion coupling beam; the directions of the center lines of the two detection mass bodies in each group of mass body units are parallel to each other and parallel to the direction of the other arm in the cross center beam.

2. The motion decoupled MEMS gyroscope sensor structure according to claim 1, characterized in that: The two ends of the horizontal arm of the T-shaped motion coupling beam are fixedly connected to two adjacent groups of mass body units, and the two side surfaces of the vertical arm of the T-shaped beam are fixedly connected to the two adjacent groups of mass body units through connecting protrusions; The two side surfaces of each of the four arms of the cross-shaped motion coupling beam are fixedly connected to a group of mass body units through connecting protrusions, and the four arms of the cross-shaped motion coupling beam are flush with the vertical arms of the four T-shaped motion beams respectively.

3. The motion decoupled MEMS gyroscope sensor structure according to claim 1 or 2, characterized in that: The driving mass body is supported by multiple groups of symmetrically distributed driving beams; Multiple groups of driving beams are evenly distributed around the driving mass body, and the structural dimensions are consistent, ensuring that the rigidity of each axial direction of the driving beam is consistent; One end of the driving beam is fixed, and the other end provides supporting force for the driving mass body.

4. The motion decoupled MEMS gyroscope sensor structure according to claim 3, characterized in that: The driving beam is a composite beam structure or a single cantilever beam structure, and the relationship between the beams is parallel.

5. The motion decoupled MEMS gyroscope sensor structure according to claim 4, characterized in that: The detection mass body is supported by multiple groups of symmetrically distributed detection beams; Multiple groups of detection beams are evenly distributed around the detection mass body, and the structural dimensions are consistent to ensure that the stiffness of each axial direction of the detection beam is consistent; Among them, one end of the detection beam is fixed, and the other end provides supporting force for the detection mass body.

6. The motion decoupled MEMS gyroscope sensor structure according to claim 5, characterized in that: The detection beam is a composite beam structure or a single cantilever beam structure, and the relationship between the beams is parallel.

7. The motion decoupled MEMS gyroscope sensor structure according to claim 1, characterized in that: The decoupling beam is a single cantilever beam or a folded beam; The T-shaped motion coupling beam and the cross-shaped motion coupling beam are both composite beams, including a single cantilever beam and a folded beam; The width of the decoupling beam is 2-10um, and the length is 20-50 times the width; The width of the Y-beam structure is 2-10um, and the length is 2-5 times of the width.

8. The motion decoupled MEMS gyroscope sensor structure according to claim 5, characterized in that: The width of the driving beam is 2-10um, and the length is 50-100 times the width; The detection beam has a width of 2-10 um and a length of 50-100 times the width.

9. A MEMS gyroscope, characterized in that: The motion-decoupled MEMS gyroscope sensor structure described in any one of claims 1 to 8 is used as a core component.

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