A MEMS gyroscope based on rotation mode

Abstract

The present invention provides a MEMS gyroscope based on a rotational mode, comprising an anchor point, at least two driving structures elastically connected to the outside of the anchor point, a mass group connected to the driving structure, and a coupling beam connecting adjacent driving structures, characterized in that the mass group comprises two detection components connected to the driving structure away from the anchor point, the two detection components are respectively arranged on opposite sides of the driving structure, the detection component comprises two mass blocks both connected to the driving structure and arranged at intervals, and a detection transducer arranged below or above the mass block, at least part of the mass block extends to the outside of the driving structure. By adopting a symmetrical layout of both the mass block and the detection transducer, differential detection is facilitated; in the out-of-plane swing mode, most of the mass blocks are involved in angular velocity sensitivity, and the out-of-plane large-area detection transducer is used for detection, which effectively improves the electromechanical coupling coefficient of the gyroscope detection, and improves the sensitivity and signal-to-noise ratio of the gyroscope detection.

Description

[Technical field]

[0001] The present invention relates to the technical field of gyroscopes, and in particular to a MEMS gyroscope based on a rotational mode. [Background technology]

[0002] Micromechanical gyroscope, or MEMS (Micro Electro Mechanical systems) gyroscope, is a miniature angular velocity micro sensor made by micromachining technology and microelectronics process. It has a wide range of applications in the consumer electronics market due to its small size, low power consumption and easy processing. In recent years, with the gradual improvement of the performance of MEMS gyroscopes, it has been widely used in the fields of automobiles, industry, virtual reality, etc. The MEMS out-of-plane swing gyroscope is a typical representative of MEMS out-of-plane detection gyroscopes. The driving mode of the MEMS swing gyroscope swings around the axis of the vertical mass block. When the angular velocity Ω is applied, due to the Coriolis effect, the gyroscope transfers energy to the sensitive mode, causing the vibration disk to swing out-of-plane relative to the drive. The size of Ω can be obtained by detecting the displacement of the out-of-plane swing.

[0003] The MEMS oscillating gyroscope in the related art cannot realize differential detection of all axes and has low sensitivity. [Summary of the invention]

[0004] The object of the present invention is to provide a gyroscope which is easy to realize differential detection and has high sensitivity.

[0005] The technical solution of the present invention is as follows: a MEMS gyroscope based on a rotational mode is provided, comprising an anchor point, at least two driving structures elastically connected to the outside of the anchor point, a mass group connected to the driving structure, and a coupling beam connecting adjacent driving structures, the mass group comprising two detection components connected to the driving structure away from the anchor point side, the two detection components are respectively arranged on two opposite sides of the driving structure, the detection components comprise two mass blocks both connected to the driving structure and arranged at intervals, and a detection transducer arranged below or above the mass blocks, and at least a portion of the mass blocks extends to the outside of the driving structure.

[0006] Furthermore, the angle between the two mass blocks of the same detection assembly and the sides away from the interval is less than 180°.

[0007] Furthermore, the driving structure includes two connecting parts respectively arranged on opposite sides of the anchor point, and two elastic parts respectively arranged on opposite sides of the anchor point and connected to the corresponding connecting parts away from the anchor point. The two elastic parts are arranged at intervals, and the two ends of the elastic parts are respectively connected to the adjacent edges of the two detection components.

[0008] Furthermore, the driving structure also includes at least two flexible beams connecting the anchor point and the connecting portion, and the anchor point has a first accommodating groove for accommodating the corresponding flexible beams.

[0009] Furthermore, the first accommodating groove includes a main groove close to the anchor point and a connecting groove extending from the main groove toward away from the anchor point; the flexible beam includes a connecting beam with one end connected to the connecting portion and the other end extending into the connecting groove, and a fixed beam with one end connected to the connecting beam and the other end connected to the anchor point, and the fixed beam is accommodated in the main groove.

[0010] Furthermore, the coupling beam connects the two connecting parts.

[0011] Further, the anchor point has a second accommodating groove for accommodating the coupling beam, the second accommodating groove includes a mounting groove located between the two connecting parts and two coupling grooves with the same structure that are relatively arranged on both sides of the mounting groove, the mounting groove is connected to the coupling groove, and the coupling groove has an opening at one end close to the anchor point; the coupling beam includes a mounting beam arranged in the mounting groove and two elastic arms connected to the mounting beam at one end and respectively connected to the corresponding connecting parts at the other end, the elastic arms are arranged in the corresponding coupling grooves and extend from the openings to be connected to the corresponding connecting parts.

[0012] Furthermore, the detection transducer includes a positive electrode and a negative electrode, and the positive electrode and the negative electrode are respectively arranged above or below the two mass blocks of the same detection component, and the positive electrode and the negative electrode are symmetrically arranged on the corresponding mass blocks of the two detection components with the anchor point center.

[0013] Furthermore, the driving structure also includes a driving transducer arranged on the elastic part.

[0014] Further, the elastic portion includes at least two mounting portions which are arranged on the connecting portion side away from the anchor point and are spaced apart, a spacer portion which is arranged between two adjacent mounting portions, and a peripheral portion which is arranged on the mounting portion side away from the connecting portion, the peripheral portion is connected to the mounting portion and the spacer portion, and the mounting portion and the spacer portion are connected to the connecting portion, the peripheral portion is respectively connected to the edges adjacent to the two detection components, and the driving transducer is arranged on the mounting portion.

[0015] The principle of the present invention is that the gyro of the x-axis angle detection scheme has two vibration modes, the first mode is the swing mode in the plane of the mass block, and the second mode is the swing mode out of the plane of the mass block; the gyro is driven by an external driving force to drive the vibration of the modal vibration mode. At this time, when the gyro is subjected to the x-axis angular velocity ω, according to the Coriolis principle, the angular velocity ω will generate a resultant Coriolis force along the z-axis direction, and the resultant Coriolis force will force the new scheme gyro to generate vibration with a y-axis detection modal vibration mode. Finally, by detecting the vibration displacement of the new scheme gyro along the z-axis direction, the magnitude of the angular velocity ω can be obtained.

[0016] The beneficial effects of the present invention are as follows: in the MEMS gyroscope based on the rotation mode provided by the present invention, the mass block and the detection transducer are symmetrically arranged, which is convenient for differential detection; in the out-of-plane swing mode, most of the mass block is involved in angular velocity sensitivity, and the out-of-plane large-area detection transducer is used for detection, which effectively improves the electromechanical coupling coefficient of the gyroscope detection, and improves the sensitivity and signal-to-noise ratio of the gyroscope detection.

Brief Description of the Drawings

[0017] Figure 1 A schematic diagram of the structure of a MEMS gyroscope based on a rotational mode provided by the present invention;

[0018] Figure 2 For the present invention Figure 1 A partial enlarged view of the circled portion A;

[0019] Figure 3 It is a schematic diagram of electrode distribution of the present invention;

[0020] Figure 4 A schematic diagram of a driving mode of a MEMS gyroscope based on a rotational mode provided by the present invention;

[0021] Figure 5 A schematic diagram of the detection mode of the MEMS gyroscope based on the rotation mode provided by the present invention. [Specific implementation method]

[0022] The present invention will be further described below in conjunction with the accompanying drawings and implementation modes.

[0023] See also Figures 1 to 5The present invention provides a MEMS gyroscope based on a rotational mode, comprising an anchor point 1, at least two driving structures 2 elastically connected to the outside of the anchor point 1, a mass group 3 connected to the driving structure 2, and a coupling beam 4 connecting adjacent driving structures, the mass group 3 comprising two detection components 31 connected to the side of the driving structure 2 away from the anchor point 1, the two detection components 31 are respectively arranged on two opposite sides of the driving structure 2, the detection component 31 comprises two mass blocks 311 both connected to the driving structure 2 and arranged at intervals, and a detection transducer 312 arranged below or above the mass blocks 311, and at least a portion of the mass blocks 311 extends to the outside of the driving structure 2.

[0024] The x-axis angle detection scheme of this embodiment has two vibration modes. The first mode is the in-plane swing mode of the mass block (such as Figure 4 ), the second mode is the out-of-plane swing mode of the mass block (as shown Figure 5 As shown); the gyro is driven by an external driving force to drive the vibration of the modal vibration mode. At this time, when the gyro is subjected to the angular velocity ω of the x-axis, according to the Coriolis principle, the angular velocity ω will generate a resultant Coriolis force along the z-axis, and the resultant Coriolis force will force the new scheme gyro to generate vibration of the y-axis detection modal vibration mode. Finally, by detecting the vibration displacement of the new scheme gyro along the z-axis direction, the magnitude of the angular velocity ω can be obtained.

[0025] In this embodiment, the anchor point 1 region is set in the central region of the structure, and the mass block 311 and the detection transducer 312 are symmetrically arranged to facilitate differential detection; it should be noted that the detection transducer 312 arranged below or above the mass block 311 refers to the detection transducer 312 arranged above or below the z-axis direction (i.e., Figures 3 to 5 The driving structure 2 and the detection transducer 312 are used to couple the mechanical field and the electric field of the structure, thereby providing a resonant driving force and angular velocity detection for the gyroscope. In the in-plane swing mode of the mass block 311 (also called the drive mode), the two mass blocks are configured to move concentrically and in anti-phase around the anchor point 1. The other mode is the out-of-plane swing mode of the mass block (also called the sense mode), and the two mass blocks 311 flip in anti-phase. In the out-of-plane swing mode, most of the mass blocks 311 are involved in angular velocity sensitivity (i.e., most of the mass blocks extend to the outside of the driving structure 2). The out-of-plane large-area detection transducer 312 is used for detection, thereby effectively improving the electromechanical coupling coefficient of the gyroscope detection, and improving the sensitivity and signal-to-noise ratio of the gyroscope detection.

[0026] Furthermore, the angle between the sides away from the interval of the mass block 311 of the same detection component 31 is less than 180°; the driving structure 2 includes two connecting parts 21 respectively arranged on the opposite sides of the anchor point 1, and two elastic parts 22 respectively arranged on the opposite sides of the anchor point 1 and connected to the corresponding connecting parts 21 away from the anchor point 1, the two elastic parts 22 are arranged at intervals, and the two ends of the elastic parts 22 are respectively connected to the edges adjacent to the two detection components 31; the driving structure 2 also includes at least two flexible beams 23 connecting the anchor point 1 and the connecting part 21, the anchor point 1 has a first accommodating groove 11 for accommodating the corresponding flexible beams 23; the first accommodating groove 11 includes a main groove 111 close to the anchor point 1 and a connecting groove 112 extending from the main groove 111 toward the direction away from the anchor point 1; the flexible beam 23 includes one end connected to the connecting part 21 and the other end connected to the connecting part 21. A connecting beam 231 with one end extending into the connecting groove 112 and a fixed beam 232 with one end connected to the connecting beam 231 and the other end connected to the anchor point 1, the fixed beam 232 is accommodated in the main groove 111; the driving structure 2 also includes a driving transducer 24 arranged on the elastic part 22; the elastic part 22 includes at least two mounting parts 221 arranged on the side of the connecting part 21 away from the anchor point 1 and spaced apart, a spacing part 222 arranged between two adjacent mounting parts 221, and a peripheral part 223 arranged on the side of the mounting part 221 away from the connecting part 21, the peripheral part 223 is connected to the mounting part 221 and the spacing part 222, and the mounting part 221 and the spacing part 222 are connected to the connecting part 21, the peripheral part 223 is respectively connected to the edges adjacent to the two detection components 31, and the driving transducer 24 is arranged on the mounting part 221.

[0027] In the present embodiment, the driving mode of the gyroscope is a differential comb drive, which can effectively improve the stability of the gyroscope drive and achieve a larger driving displacement; increase the mechanical sensitivity of the gyroscope, which is beneficial to the bias stability of the sensor; at the same time, since the two mass blocks 311 rotate in opposite phases around the center of a single anchor point 1, and since the connecting portion 21 is connected to the anchor point 1 through a flexible beam 23, and the connecting portion 21 is connected to the mass block 311, the structure has an in-plane rotational degree of freedom and a lower anchor point 1 loss, and a greater area utilization rate; increase the sensitivity of the detection structure, reduce the mechanical noise of the gyroscope; increase the area utilization rate of the chip, and realize the miniaturization of the gyroscope.

[0028] Specifically, an anchor point 1 is set in the central area of ​​the structure, and a connecting portion 21 is set around the anchor point 1 as the center ring for setting a flexible beam 23. The two mass blocks 311 of the two detection components 31 are set at intervals, and the flexible beam 23 and the connecting portion 21 are used to connect to the anchor point 1, that is, one end of the two mass blocks 311 on the same side is connected through the anchor point 1, and the other ends are separated from each other. At this time, the connecting line from the anchor point 1 and the interval between the two mass blocks 311 on the same side is the dividing line, which divides the two mass blocks 311 on the same side into two different monomers, and the extension line of the connecting line also divides the two mass blocks 311 on the other side into two different monomers; because the two elastic parts 22 are connected through the connecting portion 21, that is, the elastic part 22 extends outward from the connecting portion 21, and the two ends of the extended side are respectively connected to the edges adjacent to the two detection components 31 (that is, the two ends are respectively connected to the same portion of the dividing line). The edges of the two mass blocks 311 on the two sides are connected), when the gyroscope is in the driving mode, the two mass blocks 311 on the same detection component 31 move concentrically and anti-phase around the anchor point 1. Since the elastic part 22 has an elastic force, the elastic part 22 is compressed at this time, and the two mass blocks 311 on the other detection component 31 move concentrically toward each other around the anchor point 1. Since a number of fixed comb-tooth electrodes and movable comb-tooth electrodes are interlaced with each other to form a number of differential capacitors, the fixed comb-tooth electrodes and movable comb-tooth electrodes on the elastic part 22 are used for detection to generate an external driving force required to force the gyroscope to vibrate in a driving mode vibration type; it should be noted that a plurality of flexible beams 23 are arranged at intervals around the anchor point 1; a plurality of first accommodating grooves 11 are arranged at intervals around the anchor point 1; preferably, the flexible beams 23 and the first accommodating grooves 11 on the same side of the dividing line are arranged at equal angles around the anchor point 1. The mounting portions 221 are arranged at equal angles around the anchor point 1 , and spacing portions are arranged at the spacings to provide a compression area when the elastic portion 22 is compressed; the peripheral portions 223 are respectively connected to the adjacent edges of the two detection components 31 .

[0029] Further, the coupling beam 4 connects the two connecting parts 21; the anchor point 1 has a second accommodating groove 12 for accommodating the coupling beam 4, the second accommodating groove 12 includes a mounting groove 121 located between the two connecting parts 21 and two coupling grooves 122 with the same structure arranged on both sides of the mounting groove 121, the mounting groove 121 is connected to the coupling groove 122, the end of the coupling groove 122 close to the anchor point 1 has an opening 1221, and the coupling groove 122 has a plurality of bending parts 1222; the coupling beam 4 includes a mounting beam 41 arranged in the mounting groove 121 and one end connected to the mounting beam 41 Two elastic arms 42 are connected and the other ends are respectively connected to the corresponding connecting parts 21, the elastic arms 42 are arranged in the corresponding coupling slots 122 and extend from the opening 1221 to be connected to the corresponding connecting parts 21; the detection transducer 312 includes a positive electrode 3121 and a negative electrode 3122, the positive electrode 3121 and the negative electrode 3122 are respectively arranged above or below the two mass blocks 311 of the same detection component 31, and the positive electrode 3121 and the negative electrode 3122 are symmetrically arranged on the corresponding mass blocks 311 of the two detection components 31 with the anchor point 1 as the center.

[0030] In this embodiment, the gyro detection modes are all anti-phase vibrations, and the total torque of the structure is balanced, so gyro differential detection can be achieved; it is effectively immune to the influence of acceleration shock and orthogonal error; and the connecting parts 21 are elastically connected through a coupling structure to achieve anti-phase movement between different mass blocks 311, effectively forming differential detection.

[0031] Specifically, the ends of adjacent connecting grooves 112 away from the anchor point 1 are connected by an annular gap 25, and the thickness of the annular gap 25 is greater than the groove wall thickness of the connecting groove 112, and the thickness of the annular gap 25 is also greater than the groove wall thickness of the second accommodating groove 12. When the gyroscope is in the detection mode, when the two mass blocks 311 flip in opposite phases, the larger thickness of the annular gap 25 can avoid breakage and can play a better role in strengthening fixation; the two coupling beams 4 are correspondingly arranged on both sides of the annular gap 25, and the two second accommodating grooves 12 are correspondingly arranged on both sides of the annular gap 25; furthermore, the interval between two adjacent connecting grooves 112 located on different sides of the dividing line is greater than the interval between two adjacent connecting grooves 112 located on the same side of the dividing line, and the second accommodating grooves 12 are arranged on different sides of the dividing line. At the interval between two adjacent connecting grooves 112, and the second accommodating groove 12 is connected to the annular gap 25, the two second accommodating grooves 12 are relatively arranged on both sides of the anchor point 1; the coupling beam 4 is an elastic structure, and the multiple bending portions 1222 of the coupling groove 122 are used to enhance the strength of the structure of the coupling beam 4, and to buffer the force when the two mass blocks 311 flip in opposite phases, increase the toughness of the coupling beam 4 connecting the annular gap 25 and the connecting portion 21, and avoid breakage; furthermore, the two connecting portions 21 are elastically connected through the coupling beam 4, so as to realize the anti-phase movement between different mass blocks 311 and effectively form differential detection; it should be noted that, in the present embodiment, there are at least 7 bending portions 1222, which can enhance the toughness and strength of the coupling beam 4 to a large extent. The two mass blocks 311 on the same detection component 31 are respectively provided with a positive electrode 3121 and a negative electrode 3122, and the two mass blocks 311 located on the same side of the dividing line are respectively provided with a positive electrode 3121 and a negative electrode 3122; at this time, the positive electrode 3121 and the negative electrode 3122 form a number of capacitors for detecting the vibration displacement of the gyroscope along the vibration direction of the measured mode.

[0032] In summary, the MEMS gyroscope based on the rotation mode provided by the present invention is not only convenient for realizing differential detection, but also improves the sensitivity and signal-to-noise ratio of gyroscope detection; the driving mode using the differential comb drive can effectively improve the stability of the gyroscope drive, and at the same time can realize a larger driving displacement, increase the mechanical sensitivity of the gyroscope, and is beneficial to the bias stability of the sensor; the detection mode using the anti-phase vibration can realize gyroscope differential detection, and effectively immunize against the influence of acceleration shock and orthogonal error; and the structure of the gyroscope has lower anchor point loss and greater area utilization, thereby realizing the miniaturization of the gyroscope.

[0033] The above description is only an implementation mode of the present invention. It should be pointed out that, for ordinary technicians in this field, improvements can be made without departing from the creative concept of the present invention, but these all belong to the protection scope of the present invention.

Claims

1. A MEMS gyroscope based on a rotational mode, comprising an anchor point, at least two drive structures elastically connected to the outside of the anchor point, a mass group connected to the drive structure, and a coupling beam connecting adjacent drive structures, characterized in that: The driving structure is in a circular ring shape, and the mass group includes two detection components connected to the driving structure away from the anchor point side, and the two detection components are respectively arranged on opposite sides of the driving structure. The detection component includes two mass blocks that are both connected to the driving structure and arranged at intervals, and a detection transducer arranged below or above the mass blocks. The mass blocks and the detection transducers are both symmetrically arranged, and at least part of the mass blocks extends to the outside of the driving structure. The two mass blocks are configured to move in opposite phases around the anchor point, and the two mass blocks flip in opposite phases.

2. The MEMS gyroscope based on rotational mode according to claim 1, characterized in that: The angle between the two mass blocks of the same detection assembly and the sides away from the interval is less than 180°.

3. The MEMS gyroscope based on rotational mode according to claim 1, characterized in that: The driving structure includes two connecting parts respectively arranged on opposite sides of the anchor point, and two elastic parts respectively arranged on opposite sides of the anchor point and connected to the corresponding connecting parts away from the anchor point. The two elastic parts are arranged at intervals, and the two ends of the elastic parts are respectively connected to the adjacent edges of the two detection components.

4. The MEMS gyroscope based on rotational mode according to claim 3, characterized in that: The driving structure further includes at least two flexible beams connecting the anchor point and the connecting portion, and the anchor point has a first accommodating groove for accommodating the corresponding flexible beams.

5. The MEMS gyroscope based on rotational mode according to claim 4, characterized in that: The first accommodating groove includes a main groove close to the anchor point and a connecting groove extending from the main groove toward away from the anchor point; the flexible beam includes a connecting beam with one end connected to the connecting part and the other end extending into the connecting groove, and a fixed beam with one end connected to the connecting beam and the other end connected to the anchor point, and the fixed beam is accommodated in the main groove.

6. The MEMS gyroscope based on rotational mode according to claim 4, characterized in that: The coupling beam connects the two connecting parts.

7. The MEMS gyroscope based on rotational mode according to claim 6, characterized in that: The anchor point has a second accommodating groove for accommodating the coupling beam, the second accommodating groove includes a mounting groove located between the two connecting parts and two coupling grooves with the same structure that are relatively arranged on both sides of the mounting groove, the mounting groove is communicated with the coupling groove, and the coupling groove has an opening at one end close to the anchor point; the coupling beam includes a mounting beam arranged in the mounting groove and two elastic arms connected to the mounting beam at one end and respectively connected to the corresponding connecting parts at the other end, the elastic arms are arranged in the corresponding coupling grooves and extend from the openings to be connected to the corresponding connecting parts.

8. The MEMS gyroscope based on rotational mode according to claim 3, characterized in that: The detection transducer includes a positive electrode and a negative electrode, and the positive electrode and the negative electrode are respectively arranged above or below the two mass blocks of the same detection component, and the positive electrode and the negative electrode are symmetrically arranged on the corresponding mass blocks of the two detection components with the anchor point as the center.

9. The MEMS gyroscope based on rotational mode according to claim 3, characterized in that: The driving structure further includes a driving transducer arranged on the elastic part.

10. The MEMS gyroscope based on rotational mode according to claim 9, characterized in that: The elastic portion includes at least two mounting portions which are arranged on the side of the connecting portion away from the anchor point and are spaced apart from each other, a spacer portion which is arranged between two adjacent mounting portions, and a peripheral portion which is arranged on the side of the mounting portion away from the connecting portion, the peripheral portion is connected to the mounting portion and the spacer portion, and the mounting portion and the spacer portion are connected to the connecting portion, the peripheral portion is respectively connected to the edges adjacent to the two detection components, and the driving transducer is arranged on the mounting portion.

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