A frame decoupling structure and a MEMS resonator gyroscope having the same

Abstract

This invention discloses a frame decoupling structure and a MEMS resonant gyroscope incorporating it, belonging to the field of microelectromechanical systems (MEMS) technology. The frame decoupling structure is a centrally symmetric structure, comprising a drive decoupling frame and a detection decoupling frame. The drive decoupling frame is connected to a fixed anchor point via a first elastic support structure with low stiffness in the drive direction and high stiffness in the detection direction, and is connected to a mass block via a second elastic support structure with high stiffness in the drive direction and low stiffness in the detection direction. The detection decoupling frame is connected to the fixed anchor point via a third elastic support structure with low stiffness in the detection direction and high stiffness in the drive direction, and is connected to the mass block via a fourth elastic support structure with high stiffness in the detection direction and low stiffness in the drive direction. This design physically separates the mechanical paths of drive and detection using anisotropic stiffness beams, thereby effectively suppressing orthogonality errors and improving the gyroscope's performance and production yield.

Description

Technical Field

[0001] This invention relates to the field of microelectromechanical systems (MEMS) technology, specifically to a frame decoupling structure and a MEMS resonant gyroscope having the same. Background Technology

[0002] A microelectromechanical system (MEMS) resonant gyroscope is an inertial sensor that uses the Coriolis effect to measure angular velocity. To obtain high-precision measurement results, it is usually required that the resonant frequency of the gyroscope's driving mode be precisely matched with the resonant frequency of the detection mode.

[0003] However, in actual micro-nano fabrication processes, unavoidable manufacturing errors can lead to asymmetries in the microstructure of the gyroscope, resulting in orthogonal errors. These orthogonal errors manifest as follows: even without angular velocity input, the vibration of the driving mode can couple to the detection mode, generating an interference signal at the detection output that has the same frequency as the driving signal. This coupling interference severely affects the demodulation accuracy of the true angular velocity signal, thus reducing the gyroscope's performance.

[0004] To suppress orthogonality errors and improve the overall performance of gyroscopes, the use of a multi-mass centrosymmetric structure with N-fold rotational symmetry (N being a natural number greater than or equal to 4) has become a mainstream design trend. This type of structure inherently possesses good resistance to thermal stress and common-mode interference suppression capabilities. Existing technologies have also proposed using elastic beams with anisotropic stiffness (e.g., folded beams) to achieve motion decoupling; for example, a complex elastic beam system can be used to directly connect the central anchor point to symmetrically distributed mass blocks. However, this direct connection method results in intertwined mechanical transmission paths for drive and detection, lacking clear physical isolation, leading to limited motion decoupling efficiency and complex structural design and optimization processes. Therefore, existing technologies have not yet provided a decoupling scheme that can effectively match the centrosymmetric gyroscope body, has a clear structure, and achieves efficient physical path separation. Summary of the Invention

[0005] The purpose of this invention is to provide a frame decoupling structure and a MEMS resonant gyroscope having the same, in order to solve the problems in the prior art such as poor matching between the decoupling structure and the centrally symmetric gyroscope body, unclear decoupling path, and difficulty in effectively suppressing orthogonal error while maintaining the advantage of structural symmetry.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A frame decoupling structure and a MEMS resonant gyroscope having the same are disclosed, applicable to a centrosymmetric MEMS resonant gyroscope. The MEMS resonant gyroscope includes at least one fixed anchor point and N mass blocks distributed centrosymmetrically, where N is a natural number greater than or equal to 4. The MEMS resonant gyroscope has mutually orthogonal driving and detection directions. The frame decoupling structure is characterized by being a centrosymmetric dual-frame decoupling structure, comprising:

[0008] A drive decoupling frame is connected to the fixed anchor point via a first elastic support structure and to the mass block via a second elastic support structure.

[0009] The detection decoupling frame is connected to the fixed anchor point through a third elastic support structure and to the mass block through a fourth elastic support structure.

[0010] in:

[0011] The first elastic support structure has low stiffness in the driving direction and high stiffness in the detection direction;

[0012] The second elastic support structure has high stiffness in the driving direction and low stiffness in the detection direction;

[0013] The third elastic support structure has low stiffness in the detection direction and high stiffness in the driving direction.

[0014] The fourth elastic support structure has high stiffness in the detection direction and low stiffness in the driving direction.

[0015] As a further embodiment of the present invention: the first elastic support structure, the second elastic support structure, the third elastic support structure and the fourth elastic support structure are selected to be composed of a folded beam structure or a composite cantilever beam structure.

[0016] As a further aspect of the present invention: each of the first elastic support structure, the second elastic support structure, the third elastic support structure and the fourth elastic support structure has a stiffness difference ratio between its high stiffness direction and its low stiffness direction that is greater than 10 times.

[0017] As a further aspect of the present invention: N is any natural number between 4 and 12.

[0018] As a further aspect of the present invention, it also includes a driving electrode disposed on the driving decoupling frame and a detection electrode disposed on the detection decoupling frame.

[0019] This invention also provides a frame decoupling structure applied to a centrosymmetric MEMS resonant gyroscope. The MEMS resonant gyroscope includes at least one fixed anchor point and N mass blocks distributed centrosymmetrically, where N is a natural number greater than or equal to 4. The MEMS resonant gyroscope has mutually orthogonal driving and detection directions. The frame decoupling structure is a first-order frame decoupling structure, comprising:

[0020] A drive decoupling frame is connected to the fixed anchor point via a first elastic support structure and to the mass block via a second elastic support structure.

[0021] The first elastic support structure has low stiffness in the driving direction and high stiffness in the detection direction, while the second elastic support structure has high stiffness in the driving direction and low stiffness in the detection direction.

[0022] This invention also provides a frame decoupling structure applied to a centrosymmetric MEMS resonant gyroscope. The MEMS resonant gyroscope includes at least one fixed anchor point and N mass blocks distributed centrosymmetrically, where N is a natural number greater than or equal to 4. The MEMS resonant gyroscope has mutually orthogonal driving and detection directions. The frame decoupling structure is a first-order frame decoupling structure, comprising:

[0023] The detection decoupling frame is connected to the fixed anchor point through a third elastic support structure and to the mass block through a fourth elastic support structure.

[0024] The third elastic support structure has low stiffness in the detection direction and high stiffness in the driving direction, while the fourth elastic support structure has high stiffness in the detection direction and low stiffness in the driving direction.

[0025] The present invention also provides a MEMS resonant gyroscope, comprising at least one fixed anchor point and N mass blocks distributed in a centrally symmetrical manner, where N is a natural number greater than or equal to 4. The MEMS resonant gyroscope has mutually orthogonal driving directions and detection directions, and also includes any of the above-mentioned frame decoupling structures.

[0026] Compared with the prior art, the present invention has at least the following beneficial effects:

[0027] 1. This application introduces independent driving decoupling framework and detection decoupling framework, and utilizes the ingenious connection of anisotropic stiffness beams to successfully separate the motion of the driving mode and the motion of the detection mode on the mechanical transmission path while maintaining the overall central symmetry of the MEMS resonant gyroscope structure. This effectively suppresses the orthogonal error caused by process error and reduces the stringent requirements for precise frequency matching of the driving and detection modes.

[0028] 2. By reducing the dependence on frequency matching, this application can significantly improve the production yield of high-performance MEMS resonant gyroscopes without improving the precision of existing micromachining processes. At the same time, it retains and utilizes the inherent advantages of the centrosymmetric structure, such as stronger thermal stress resistance and better common-mode suppression, which helps to comprehensively improve the performance and stability of MEMS resonant gyroscopes.

[0029] 3. This application pre-separates the driving signal and the detection signal at the mechanical structure level, so that the driving comb teeth and the detection comb teeth can be arranged on the driving decoupling frame and the detection decoupling frame respectively, which greatly reduces the demodulation difficulty and calculation error of the back-end signal processing circuit and improves the signal-to-noise ratio. Attached Figure Description

[0030] The invention will now be further described with reference to the accompanying drawings.

[0031] Figure 1 This is a schematic diagram of the overall structure of a MEMS gyroscope provided in one embodiment of this application;

[0032] Figure 2 This is a 1 / 4 schematic diagram of a dual-frame decoupling structure provided in one embodiment of this application;

[0033] Figure 3 This is a schematic diagram of the comb tooth distribution provided in one embodiment of this application;

[0034] Figure 4 A schematic diagram of a composite cantilever beam elastic structure provided in one embodiment of this application;

[0035] Figure 5 This is a schematic diagram of an eight-mass gyroscope structure provided in one embodiment of this application;

[0036] Figure 6 This is a schematic diagram of a first-level decoupling structure provided in one embodiment of this application.

[0037] In the diagram: 10, mass block; 20, drive decoupling frame; 21, first elastic support structure; 22, second elastic support structure; 30, detection decoupling frame; 31, third elastic support structure; 32, fourth elastic support structure; 40, fixed anchor point; 51, drive comb teeth; 52, detection comb teeth; 60, composite cantilever beam structure; 70, eight-mass gyroscope structure; 80, first-level decoupling structure. Detailed Implementation

[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] Example 1

[0040] This embodiment provides a dual-frame decoupling structure for a centrosymmetric microelectromechanical system (MEMS) resonant gyroscope, as well as a MEMS resonant gyroscope incorporating this dual-frame decoupling structure. This embodiment aims to elaborate in detail a complete technical solution capable of efficiently separating the driving mode and the detection mode along the mechanical transmission path.

[0041] Please see Figure 1 This document presents a top view of the complete MEMS resonant gyroscope structure in one embodiment of this application. The overall structure of this MEMS resonant gyroscope exhibits central symmetry; specifically, in this embodiment, it displays fourfold rotational symmetry. The core of this overall MEMS resonant gyroscope structure includes a fixed anchor point 40 located at the geometric center, and four mass blocks 10 distributed centrally symmetrically around the fixed anchor point 40. The fixed anchor point 40 serves as the static reference for the entire movable structure and is typically firmly connected to the device substrate using micromachining techniques. The mass blocks 10 are the core inertial units of the MEMS resonant gyroscope, and their changes in motion form the basis for angular velocity measurement. It is understood that this N-fold symmetry layout (N=4 in this example) helps to offset thermal stress caused by environmental factors such as temperature changes and effectively suppresses common-mode vibration interference from the substrate, laying the structural foundation for achieving a high-performance gyroscope.

[0042] To more clearly reveal the core decoupling mechanism of the embodiments of this application, please refer to... Figure 2 The image is Figure 1 The diagram shows an enlarged view of one-quarter of the overall structure of the MEMS resonant gyroscope. Figure 2 The dual-frame decoupling structure connecting the fixed anchor point 40 and the mass block 10 is shown in detail. This dual-frame decoupling structure also follows the principle of central symmetry and mainly includes a drive decoupling frame 20 and a detection decoupling frame 30. The drive decoupling frame 20 and the detection decoupling frame 30 are physically independent and are connected to the fixed anchor point 40 and the mass block 10 through four sets of elastic support structures with special stiffness anisotropy, thereby constructing two mechanically isolated force transmission paths.

[0043] Specifically, the drive decoupling frame 20 is a centrally symmetrical (fourfold symmetrical in this example) ring or frame structure. The drive decoupling frame 20 is connected to the central fixed anchor point 40 through the first elastic support structure 21, and simultaneously connected to the peripheral mass block 10 through the second elastic support structure 22. The number of the first elastic support structure 21 and the second elastic support structure 22 corresponds to the symmetry order of the MEMS resonant gyroscope, that is, there are four of each, and they are distributed symmetrically at 90°.

[0044] Correspondingly, the detection decoupling frame 30 is also a centrally symmetrical (fourfold symmetrical) ring or frame structure, which is connected to the central fixed anchor point 40 through the third elastic support structure 31, and connected to the peripheral mass block 10 through the fourth elastic support structure 32. Similarly, there are four of each of the third elastic support structure 31 and the fourth elastic support structure 32, distributed symmetrically at 90°. It should be noted that in the planar layout of this embodiment, the drive decoupling frame 20 and the detection decoupling frame 30 can be located in the same structural layer. For example, the detection decoupling frame 30 can be arranged inside or outside the drive decoupling frame 20 to ensure that there is no direct physical contact between them.

[0045] The core technical concept of this embodiment lies in the meticulous design of the stiffness characteristics of the four sets of elastic support structures to achieve precise constraints on the direction of motion. For a typical MEMS resonant gyroscope, its operating modes include a driving mode and a detection mode, and the motion directions of the driving mode and the detection mode are usually orthogonal to each other. In this embodiment, the motion direction of the mass block 10 along the radial direction (i.e., the direction connecting the center and the center of mass of the mass block) is defined as the driving direction, while the motion direction along the tangential direction (i.e., the direction perpendicular to the radial direction) is defined as the detection direction.

[0046] The first elastic support structure 21 connects the fixed anchor point 40 and the drive decoupling frame 20. Its stiffness characteristics are designed to exhibit low stiffness in the driving direction and high stiffness in the detection direction. This design allows the drive decoupling frame 20 to resonate freely relative to the fixed anchor point 40 in the driving direction, while any undesirable displacement in the detection direction is greatly suppressed.

[0047] The second elastic support structure 22 connects the drive decoupling frame 20 and the mass block 10. Its stiffness characteristics are designed to be opposite to those of the first elastic support structure 21: high stiffness in the driving direction and low stiffness in the detection direction. This design ensures that when the drive decoupling frame 20 moves in the driving direction, the motion can be efficiently and losslessly transmitted to the mass block 10, as if it were a rigid connection; while in the detection direction, it allows the mass block 10 to move freely relative to the drive decoupling frame 20, thereby avoiding the constraint of the drive decoupling frame 20 on the detection motion of the mass block 10.

[0048] The third elastic support structure 31 connects the fixed anchor point 40 and the detection decoupling frame 30. Its stiffness characteristics are designed to exhibit low stiffness in the detection direction and high stiffness in the driving direction. This design allows the detection decoupling frame 30 to respond freely to small displacements caused by Coriolis forces relative to the fixed anchor point 40 in the detection direction, while any undesirable displacements in the driving direction (such as displacements caused by drive crosstalk) are greatly suppressed.

[0049] The fourth elastic support structure 32 connects the detection decoupling frame 30 and the mass block 10. Its stiffness characteristics are designed to be opposite to those of the third elastic support structure 31: high stiffness in the detection direction and low stiffness in the driving direction. This design ensures that when the mass block 10 moves in the detection direction, the motion can be efficiently and losslessly transmitted to the detection decoupling frame 30 for subsequent signal pickup; while in the driving direction, it allows the mass block 10 to move freely relative to the detection decoupling frame 30, thereby effectively isolating the large vibrations of the mass block 10 in the driving direction from the detection decoupling frame 30.

[0050] As a preferred implementation, in this embodiment, the first elastic support structure 21, the second elastic support structure 22, the third elastic support structure 31, and the fourth elastic support structure 32 all adopt folded beam structures. Folded beam structures are cantilever beam composite structures widely used in microelectromechanical systems (MEMS) design. By rationally designing the beam length, width, and number of folds, significantly different stiffnesses in two orthogonal directions can be easily achieved. To achieve the ideal decoupling effect, preferably, the stiffness difference ratio between the high-stiffness direction and the low-stiffness direction of these elastic support structures is designed to be greater than 10 times, or even 100 times or higher. This huge stiffness ratio is key to achieving precise constraint of motion direction and efficient decoupling.

[0051] See Figure 3 The figure schematically illustrates the layout of the driving and detection electrodes. In this embodiment, a set of driving comb teeth 51 is disposed on the driving decoupling frame 20, and the cooperating fixed comb teeth (not shown) are fixed on the substrate. Another set of detection comb teeth 52 is disposed on the detection decoupling frame 30, and the cooperating fixed comb teeth (not shown) are also fixed on the substrate. This electrode layout directly reflects the beneficial effect of this application, namely, that driving and detection are also separated at the electrical interface level.

[0052] The operation of a MEMS resonant gyroscope begins with the excitation of the drive mode. By applying an AC drive voltage (typically including a DC bias voltage and an AC excitation signal) between the drive comb teeth 51 and the fixed comb teeth, a periodically varying electrostatic force is generated along the drive direction (radial). This electrostatic force acts directly on the drive decoupling frame 20. The low stiffness of the first elastic support structure 21 in the drive direction allows the drive decoupling frame 20 to be effectively excited with a small driving force and to resonate around its equilibrium position along the drive direction. Simultaneously, the high stiffness of the second elastic support structure 22 in the drive direction allows the motion of the drive decoupling frame 20 to be transmitted to the mass block 10 with almost no attenuation, causing the mass block 10 to also resonate along the drive direction at the same frequency and phase.

[0053] During this driving process, the role of the decoupling structure is mainly reflected in the following aspects: the high stiffness of the third elastic support structure 31 in the driving direction ensures that the detection decoupling frame 30 is almost unaffected by the driving force and thus does not experience displacement in the driving direction; simultaneously, the low stiffness of the fourth elastic support structure 32 in the driving direction ensures that the large-scale driving motion of the mass block 10 is not transmitted to the detection decoupling frame 30. Therefore, even if there is structural asymmetry due to micro-machining process errors, crosstalk transmitted from the driving source to the detection end is greatly suppressed.

[0054] When the overall structure of the MEMS resonant gyroscope rotates around its sensing axis perpendicular to the plane of the drawing, i.e., when there is an angular velocity input, the mass block 10, which is resonating along the driving direction, will be subjected to the Coriolis force. The direction of this force is perpendicular to the instantaneous velocity direction of the mass block and the direction of the input angular velocity. Therefore, it will drive the mass block 10 to generate a vibration in the detection direction (tangential) that is proportional to the magnitude of the input angular velocity and has the same frequency as the driving signal.

[0055] This minute vibration in the detection direction is the target signal that needs to be precisely measured. At this point, the decoupling structure of the detection path begins to play a crucial role. Due to the high stiffness of the fourth elastic support structure 32 in the detection direction, the displacement of the mass block 10 in the detection direction is efficiently transmitted to the detection decoupling frame 30, causing it to vibrate in the same direction as the mass block 10. Simultaneously, due to the low stiffness of the third elastic support structure 31 in the detection direction, the detection decoupling frame 30 can freely respond to this motion caused by the Coriolis force without being excessively constrained by the fixed anchor point 40. The displacement of the detection decoupling frame 30 changes the spacing between its detection comb teeth 52 and the fixed comb teeth, resulting in a periodic change in the capacitance value. Through subsequent capacitance / voltage conversion and demodulation circuits, the magnitude and direction of the input angular velocity can be accurately demodulated from this capacitance change signal.

[0056] During the detection process, the decoupling structure also serves to isolate noise: the high stiffness of the first elastic support structure 21 in the detection direction prevents the drive decoupling frame 20 from displacing in the detection direction due to the detection movement of the mass block 10; while the low stiffness of the second elastic support structure 22 in the detection direction prevents the detection movement of the mass block 10 from being transmitted to the drive decoupling frame 20. This ensures that the energy of the detection mode does not leak into the drive path, thus guaranteeing the independence of the two modes.

[0057] In summary, this embodiment successfully creates mechanically "high-pass" and "low-pass" transmission paths for the driving and detection modes at the mechanical structure level by introducing physically independent driving decoupling framework 20 and detection decoupling framework 30, and constructing a specific connection topology using four sets of elastic support structures with extreme stiffness anisotropy. The driving motion is constrained along the path "fixed anchor point 40 - first elastic support structure 21 - driving decoupling framework 20 - second elastic support structure 22 - mass block 10", while the detection motion is constrained along the path "mass block 10 - fourth elastic support structure 32 - detection decoupling framework 30 - third elastic support structure 31 - fixed anchor point 40". The two paths are orthogonal and isolated, thus achieving efficient mechanical decoupling, significantly suppressing orthogonal errors caused by factors such as manufacturing errors, and ultimately improving key performance indicators of the gyroscope such as zero-bias instability and signal-to-noise ratio.

[0058] Example 2

[0059] This embodiment provides a variant of the decoupling structure, whose overall topology, connection relationship and working principle are exactly the same as those of Embodiment 1, aiming to illustrate that the elastic support structure used to achieve stiffness anisotropy is not limited to a specific form.

[0060] In Embodiment 1, a folded beam structure is preferably used to implement the first, second, third, and fourth elastic support structures. However, it is understood that any elastic structure that exhibits high stiffness in one direction and low stiffness in its orthogonal direction can be used to implement the technical solution of this application.

[0061] Please see Figure 4 The figure schematically illustrates a composite cantilever beam structure 60 that can replace a folded beam. This composite cantilever beam structure 60 can be composed of multiple cantilever beam segments of varying lengths, widths, thicknesses, or orientations, connected in series or parallel. Through design methods such as finite element analysis, the geometric parameters of these beam segments can be optimized so that the entire composite cantilever beam structure 60 is aligned in a specific direction (e.g., ...). Figure 4When subjected to external forces in the horizontal direction (e.g., in the horizontal direction), its internal stress is mainly tensile or compressive, thus exhibiting high stiffness; while in another direction orthogonal to this direction (e.g., in the horizontal direction), its internal stress is mainly tensile or compressive, thus exhibiting high stiffness externally; Figure 4 When subjected to external force in the vertical direction, its internal stress is mainly manifested as bending stress, thus exhibiting low stiffness to the outside.

[0062] In this embodiment, the first elastic support structure 21, the second elastic support structure 22, the third elastic support structure 31, and the fourth elastic support structure 32 in Embodiment 1 are all replaced with a carefully designed composite cantilever beam structure 60. For example, the composite cantilever beam used for the first elastic support structure 21 is designed with its high stiffness direction along the detection direction and its low stiffness direction along the driving direction; while the composite cantilever beam used for the second elastic support structure 22 is designed with its high stiffness direction along the driving direction and its low stiffness direction along the detection direction, and so on for the remaining structures. Through this replacement, the stiffness difference ratio between the high stiffness direction and the low stiffness direction of each elastic support structure can also be greater than 10 times, thus satisfying the decoupling condition described in Embodiment 1.

[0063] The working process of this embodiment is completely consistent with that of Embodiment 1. The driving voltage excites the decoupling frame 20, and its motion is transmitted to the mass block 10 through the high-stiffness second elastic support structure 22 (composite cantilever beam). The detection motion caused by the Coriolis force is transmitted to the detection decoupling frame 30 through the high-stiffness fourth elastic support structure 32 (composite cantilever beam). The underlying physical principle of the entire decoupling and signal acquisition process remains unchanged.

[0064] Therefore, this embodiment demonstrates the universality of the dual-frame decoupling scheme proposed in this application. Its core lies in utilizing the stiffness anisotropy of the elastic support structure to construct separate mechanical paths. The specific structural forms for achieving this stiffness anisotropy are diverse, including but not limited to folded beam structures, composite cantilever beam structures, or any other micromechanical spring structure with similar characteristics that can be designed by those skilled in the art. This provides a wider scope of protection for the technical solution of this application.

[0065] Example 3

[0066] This embodiment aims to illustrate that the centrally symmetric decoupling structure proposed in this application has good scalability and can be flexibly applied to multi-mass block gyroscope structures with higher-order rotational symmetry, rather than being limited to the four-mass block (N=4) structure in Embodiment 1.

[0067] One design trend for high-performance MEMS resonant gyroscopes is the adoption of higher-order symmetry, such as six-fold symmetry (N=6), eight-fold symmetry (N=8), or even higher, to further enhance immunity to higher-order process errors and suppression of external interference. The decoupling scheme in this application is effectively compatible with this design trend.

[0068] Please see Figure 5 The figure schematically illustrates the application of the decoupling scheme of this application to an eight-mass gyroscope structure 70. In this design, the main body of the gyroscope consists of eight mass blocks 10 distributed in a centrally symmetrical manner (i.e., eightfold rotational symmetry, one mass block every 45°). To match this eightfold symmetric main body, the drive decoupling frame 20 and the detection decoupling frame 30 in this embodiment are also designed accordingly to have eightfold rotational symmetry.

[0069] The connection relationship is similar to that of Embodiment 1, but the number of each component is increased accordingly. The drive decoupling frame 20 is connected to the central fixed anchor point 40 through eight sets of first elastic support structures 21, and is connected to eight mass blocks 10 one-to-one through eight sets of second elastic support structures 22. Similarly, the detection decoupling frame 30 is connected to the central fixed anchor point 40 through eight sets of third elastic support structures 31, and is connected to eight mass blocks 10 one-to-one through eight sets of fourth elastic support structures 32. All these elastic support structures (e.g., folding beams) are also distributed in an eightfold symmetrical pattern.

[0070] The driving path consisting of "fixed anchor point 40 - first elastic support structure 21 - drive decoupling frame 20 - second elastic support structure 22 - mass block 10" and the detection path consisting of "mass block 10 - fourth elastic support structure 32 - detection decoupling frame 30 - third elastic support structure 31 - fixed anchor point 40" have the same stiffness configuration and working principle as the 1 / 8 structural unit described in Example 1. That is, the first elastic support structure 21 and the third elastic support structure 31 are compliant in their respective directions of motion (driving / detection) and rigid in the orthogonal direction; the second elastic support structure 22 and the fourth elastic support structure 32 are rigid in their respective directions of motion and compliant in the orthogonal direction.

[0071] The operation of this embodiment is similar to that of Embodiment 1. After the driving voltage is applied, the eight mass blocks 10 will synchronously resonate along their respective radial directions, forming an eight-fold symmetrical driving mode shape. When there is an angular velocity input, the Coriolis force will cause the eight mass blocks 10 to synchronously generate tangential motion, forming an eight-fold symmetrical detection mode shape. The eight-fold symmetrical decoupling structure in this embodiment can also effectively separate these two orthogonal, higher-order modal vibrations on the mechanical transmission path, thereby suppressing orthogonality errors.

[0072] This embodiment demonstrates that the dual-frame centrosymmetric decoupling scheme proposed in this application possesses excellent design scalability. As long as the MEMS resonant gyroscope body has an N-fold rotational symmetry structure (N being a natural number greater than or equal to 4), both the decoupling frame and the elastic support structure can be designed accordingly to match the N-fold symmetry, while maintaining the same decoupling principle. This makes this technical solution applicable not only to common four-mass and eight-mass gyroscopes, but also to the design of six-mass, twelve-mass, and even ring-shaped gyroscopes, and all other centrosymmetric gyroscope designs.

[0073] Example 4

[0074] This embodiment provides a simplified alternative technical solution employing a single-level decoupling structure. In some application scenarios where cost and structural complexity are more sensitive, but performance requirements are slightly lower than top-level, it is not necessary to decouple both the driving and detection modes simultaneously. Decoupling only one mode, i.e., using single-level decoupling, can still achieve significant performance improvements compared to traditional structures with no decoupling at all. This embodiment describes two possible single-level decoupling structures.

[0075] The first variant: retain only the driver decoupling.

[0076] Please see Figure 6 The figure schematically illustrates one-quarter of a single-stage decoupling structure 80 containing only drive decoupling. This structure can be considered as the structure of Embodiment 1 (e.g., Figure 2 A simplified form (as shown). Specifically, it retains the drive decoupling frame 20, the first elastic support structure 21 connecting the drive decoupling frame 20 and the fixed anchor point 40, and the second elastic support structure 22 connecting the drive decoupling frame 20 and the mass block 10; while the detection decoupling frame 30, the third elastic support structure 31 and the fourth elastic support structure 32 in Embodiment 1 are omitted.

[0077] In this structure, the stiffness characteristics of the first elastic support structure 21 and the second elastic support structure 22 are designed exactly the same as in Embodiment 1. That is, the first elastic support structure 21 has low stiffness in the driving direction and high stiffness in the detection direction; the second elastic support structure 22 has high stiffness in the driving direction and low stiffness in the detection direction. Since the detection decoupling frame 30 is omitted, the detection electrodes (such as detection comb teeth) need to be directly fabricated on the mass block 10, or connected to the mass block 10 through other rigid connections.

[0078] Its working process is as follows: The driving process is exactly the same as in Example 1. The driving decoupling frame 20 and its associated elastic support structure constitute a "driving force purifier," ensuring that the driving force applied to the mass block 10 is pure in direction, mainly along the driving direction, while suppressing tangential (detection direction) parasitic driving forces that may be caused by factors such as asymmetry of the driving electrodes. When there is an angular velocity input, and the mass block 10 generates motion in the detection direction, since the detection electrodes are directly connected to the mass block 10, this motion is directly picked up and converted into an electrical signal.

[0079] Although the mechanical coupling path from the driving motion to the detection motion caused by structural asymmetry still exists in this structure (due to the lack of a detection decoupling framework for isolation), since the "source" of the drive has been purified, that is, the orthogonal component of the driving force itself applied to the mass block is greatly reduced, the orthogonal error signal finally coupled to the detection end will be much lower than that of the traditional structure without any decoupling measures.

[0080] The second variant: retain only detection decoupling.

[0081] In contrast to the first variant, a structure that retains only the detection decoupling can also be designed. This structure omits the drive decoupling frame 20, the first elastic support structure 21, and the second elastic support structure 22, while retaining the detection decoupling frame 30, the third elastic support structure 31 connecting the frame to the fixed anchor point 40, and the fourth elastic support structure 32 connecting the frame to the mass block 10.

[0082] In this structure, the stiffness characteristics of the third elastic support structure 31 and the fourth elastic support structure 32 are designed exactly the same as in Embodiment 1. The driving electrode is directly fabricated on the mass block 10.

[0083] The working process is as follows: The driving voltage is directly applied to the mass block 10, causing it to vibrate along the driving direction. Due to manufacturing errors, the driving motion of the mass block 10 inevitably includes a small detection direction component, which constitutes the orthogonal error. When there is an angular velocity input, the Coriolis force also causes the mass block 10 to move in the detection direction. The total motion of the mass block 10 in the detection direction (including the true signal and the orthogonal error) is transmitted to the detection decoupling frame 30 through the high-stiffness fourth elastic support structure 32. Due to the high stiffness of the third elastic support structure 31 in the driving direction, the detection decoupling frame 30 can effectively "filter out" the vibration interference in the driving direction transmitted from the mass block 10, while its low stiffness in the detection direction allows it to respond sensitively to the motion in the detection direction. Therefore, the driving crosstalk component of the signal picked up by the detection electrodes set on the detection decoupling frame 30 is significantly suppressed.

[0084] The two single-level decoupling structures provided in this embodiment, while theoretically less effective than the dual-frame decoupling structure in Embodiment 1, are simpler in structure, occupy less chip area, and are less difficult and costly to design and manufacture. Compared to traditional non-decoupling structures, they still deliver significant performance improvements. This provides gyroscope designers with flexible design options based on different application requirements (such as consumer, industrial, and aerospace grades) and cost budgets, and serves as an effective degradation protection scope for the technical solution of this application.

[0085] The preferred embodiments of the present invention have been described in detail above and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A frame decoupling structure applied to a center-symmetric MEMS resonator gyroscope, the MEMS resonator gyroscope comprising at least one fixed anchor point and N mass blocks in a center-symmetric distribution, N being a natural number greater than or equal to 4, the MEMS resonator gyroscope having a drive direction and a detection direction orthogonal to each other, characterized in that, The frame decoupling structure is a centrally symmetric double-frame decoupling structure, comprising: A drive decoupling frame is connected to the fixed anchor point via a first elastic support structure and to the mass block via a second elastic support structure. The detection decoupling frame is connected to the fixed anchor point through a third elastic support structure and to the mass block through a fourth elastic support structure. in: The first elastic support structure has low stiffness in the driving direction and high stiffness in the detection direction; The second elastic support structure has high stiffness in the driving direction and low stiffness in the detection direction; The third elastic support structure has low stiffness in the detection direction and high stiffness in the driving direction. The fourth elastic support structure has high stiffness in the detection direction and low stiffness in the driving direction.

2. The frame decoupling structure of claim 1, wherein, The first, second, third, and fourth elastic support structures are selected to be composed of folded beam structures or composite cantilever beam structures.

3. The frame decoupling structure of claim 1, wherein, Each of the first elastic support structure, the second elastic support structure, the third elastic support structure, and the fourth elastic support structure has a stiffness difference ratio greater than 10 times between its high stiffness direction and its low stiffness direction.

4. The frame decoupling structure of claim 1, wherein, N is any natural number between 4 and 12.

5. The frame decoupling structure of claim 1, wherein, It also includes a drive electrode disposed on the drive decoupling frame and a detection electrode disposed on the detection decoupling frame.

6. A frame decoupling structure applied to a center-symmetric MEMS resonator gyroscope, the MEMS resonator gyroscope comprising at least one fixed anchor point and N mass blocks arranged in a center-symmetric manner, N being a natural number greater than or equal to 4, the MEMS resonator gyroscope having a drive direction and a detection direction orthogonal to each other, characterized in that, The framework decoupling structure is a first-level framework decoupling structure, including: A drive decoupling frame is connected to the fixed anchor point via a first elastic support structure and to the mass block via a second elastic support structure. The first elastic support structure has low stiffness in the driving direction and high stiffness in the detection direction, while the second elastic support structure has high stiffness in the driving direction and low stiffness in the detection direction.

7. A frame decoupling structure applied to a centrosymmetric MEMS resonant gyroscope, wherein the MEMS resonant gyroscope includes at least one fixed anchor point and N mass blocks distributed centrosymmetrically, where N is a natural number greater than or equal to 4, and the MEMS resonant gyroscope has mutually orthogonal driving and detection directions, characterized in that... The framework decoupling structure is a first-level framework decoupling structure, including: The detection decoupling frame is connected to the fixed anchor point through a third elastic support structure and to the mass block through a fourth elastic support structure. The third elastic support structure has low stiffness in the detection direction and high stiffness in the driving direction, while the fourth elastic support structure has high stiffness in the detection direction and low stiffness in the driving direction.

8. A MEMS resonant gyroscope, comprising at least one fixed anchor point and N mass blocks distributed in a centrally symmetrical manner, where N is a natural number greater than or equal to 4, wherein the MEMS resonant gyroscope has mutually orthogonal driving and detection directions, characterized in that... It also includes a framework decoupling structure as described in any one of claims 1-7.

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