A triaxial accelerometer based on a four-degree-of-freedom weakly coupled resonator

Abstract

This invention provides a triaxial accelerometer based on a four-degree-of-freedom weakly coupled resonator, comprising an upper and lower double-layer structure. The upper layer is a micromechanical sensing element constructed from silicon, and the lower layer is a glass substrate made of silicon dioxide, which provides mechanical support and electrical isolation. The micromechanical sensing element performs signal conversion; the lower glass substrate, formed by wet etching and metal sputtering processes, is used for signal output. This invention, based on the collaborative design of an orthogonally distributed resonant unit array and a mechanical amplification mechanism, combined with electrostatic drive and amplitude ratio detection, achieves synchronous and accurate sensing of Y-axis, X-axis, and Z-axis acceleration using a single sensing element. This overcomes the technical limitations of traditional single-axis detection modes, reduces the complexity of back-end signal processing circuitry, and improves device space utilization.

Description

Technical Field

[0001] This invention belongs to the field of microelectromechanical systems (MEMS) technology, specifically relating to a triaxial accelerometer based on a four-degree-of-freedom weakly coupled resonator. Background Technology

[0002] Miniature inertial sensors, as core components in modern precision measurement, have been widely adopted in smart terminals, automotive systems, and industrial automation due to their miniaturized structure, economic advantages, and low power consumption. Current mainstream devices primarily employ capacitive or piezoresistive sensing mechanisms, but these face significant limitations in environmental immunity and measurement sensitivity. To address this technical bottleneck, a resonant detection architecture proposed by academics exhibits unique stability advantages through its frequency signal output characteristics. Among these, the amplitude ratio detection scheme based on the weakly coupled resonance mechanism has achieved breakthrough progress in improving sensitivity and common-mode rejection ratio.

[0003] In the field of Y-axis axial acceleration detection, existing technologies are often limited by insufficient sensitivity and face challenges in complex mechanical structures and manufacturing processes. Traditional inventions measure triaxial acceleration based on three sensing elements, resulting in insufficient space utilization and maintenance difficulties. This situation has created an urgent need for a new type of four-degree-of-freedom accelerometer, which needs to achieve synergistic optimization in terms of structural compactness, detection sensitivity, and manufacturing feasibility. Summary of the Invention

[0004] Purpose of the invention: The technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing a triaxial accelerometer based on a four-degree-of-freedom weakly coupled resonator. Through a unique structural design and electrostatic drive scheme, it solves the problems of low sensitivity, high noise and poor process compatibility of traditional Z-axis accelerometers. Its core innovation lies in the fact that the present invention achieves synchronous, accurate and rapid measurement of X, Y and Z axis acceleration based on a single sensitive element.

[0005] The triaxial accelerometer of the present invention comprises an upper and lower double-layer structure, wherein the upper layer is a micromechanical sensing element constructed of silicon as a material, and the lower layer is a glass base made of silicon dioxide material, wherein the glass base is used to provide mechanical support and electrical isolation.

[0006] The micromechanical sensing element includes a first force-bearing substrate, a second force-bearing substrate, a vacant substrate, a first resonator, a second resonator, a third resonator, a fourth resonator, a Y-axis force amplification lever, an X-axis force amplification lever, a first Z-axis suppression structure, a second Z-axis suppression structure, a third Z-axis suppression structure, a fourth Z-axis suppression structure, a first motion restriction structure, a second motion restriction structure, a third motion restriction structure, a fourth motion restriction structure, a first coupling right-angle connection structure, a second coupling right-angle connection structure, a third coupling right-angle connection structure, and a fourth coupling right-angle connection structure.

[0007] The first resonator is installed on the upper side of the first load-bearing base, and the second resonator is disposed on the right side of the first load-bearing base. The first resonator and the second resonator are arranged at a 90° angle to each other.

[0008] The third resonator is located below the first load-bearing substrate and forms a 180° distribution relationship with the first resonator;

[0009] The fourth resonator is disposed on the upper part of the first load-bearing substrate, forming a 180° angle with the second resonator.

[0010] The first resonator, the second resonator, the third resonator, and the fourth resonator are rigidly connected at one end through a common anchor point. The other end of the first resonator is connected to the Y-axis force amplification lever, the other end of the second resonator is connected to the X-axis force amplification lever, the other end of the third resonator is connected to the third resonator anchor point, and the fourth resonator is connected to the fourth resonator anchor point.

[0011] The Y-axis force amplification lever is located on the upper side of the first force-bearing base, and the X-axis force amplification lever is located on the right side of the first force-bearing base.

[0012] The first Z-axis suppression structure, the second Z-axis suppression structure, the third Z-axis suppression structure, and the fourth Z-axis suppression structure are symmetrically arranged on the upper left, upper right, lower right, and lower left sides of the first load-bearing substrate, respectively.

[0013] The first, second, third, and fourth motion-restricting structures are located on the upper left, upper right, lower right, and lower left sides of the second load-bearing substrate, respectively.

[0014] The Y-axis force amplification lever is provided with a first Y-axis force output straight beam and a first Y-axis force input straight beam;

[0015] The X-axis force amplification lever is provided with a first X-axis force output straight beam and a first X-axis force input straight beam;

[0016] The first resonator is connected to the first Y-axis force output beam, and the second resonator is connected to the first X-axis force output beam;

[0017] The first Y-axis force input beam and the first X-axis force input beam are respectively connected to the upper left and lower right regions of the first load-bearing base.

[0018] The first Z-axis suppression structure is provided with a first folded beam and a second folded beam;

[0019] The second Z-axis suppression structure is provided with a third folded beam and a fourth folded beam;

[0020] The third Z-axis suppression structure is provided with a fifth folded beam and a sixth folded beam;

[0021] The fourth Z-axis suppression structure is provided with a seventh folded beam and an eighth folded beam;

[0022] The first, second, third, fourth, fifth, sixth, seventh, and eighth folded beams are all connected to the first load-bearing substrate.

[0023] The first restricting motion structure is provided with a first hook-shaped folding beam, the second restricting motion structure is provided with a second hook-shaped folding beam, the third restricting motion structure is provided with a third hook-shaped folding beam, and the fourth restricting motion structure is provided with a fourth hook-shaped folding beam.

[0024] The first hook-shaped folding beam, the second hook-shaped folding beam, the third hook-shaped folding beam, and the fourth hook-shaped folding beam are all connected to the second load-bearing substrate.

[0025] The first resonator includes a first single-ended fixed resonant beam; the second resonator includes a second single-ended fixed resonant beam; and the third resonator includes a third double-ended fixed resonant beam.

[0026] One end of the first coupling right-angle connection structure is connected to the first single-end fixed resonant beam, and the other end is connected to the fourth double-end fixed resonant beam;

[0027] The second coupling right-angle connection structure is used to connect the first single-end fixed resonant beam and the second single-end fixed resonant beam;

[0028] The third coupling right-angle connection structure connects the second single-end fixed resonant beam and the third double-end fixed resonant beam respectively.

[0029] The fourth coupling right-angle connection structure connects the third double-ended fixed resonant beam and the fourth double-ended fixed resonant beam respectively.

[0030] The first resonator and the second resonator have the same structure. The first resonator includes a first single-ended fixed resonant beam, a first driving signal application structure, a second driving signal application structure, a third driving signal application structure, a fourth driving signal application structure, a first signal detection structure, and a second signal detection structure.

[0031] The first driving signal application structure, the second driving signal application structure, the third driving signal application structure, and the fourth driving signal application structure are symmetrically arranged inside the comb teeth of the first single-end fixed resonant beam, and form a driving capacitor plate group by interlocking with the comb teeth.

[0032] The first signal detection structure and the second signal detection structure are symmetrically distributed on the outside of the comb teeth of the first single-end fixed resonant beam, and form a detection capacitor plate group with the comb teeth of the first single-end fixed resonant beam in an interlocking manner.

[0033] The third resonator includes a third resonator anchor point, a third double-ended fixed resonant beam, a ninth driving signal application structure, a tenth driving signal application structure, an eleventh driving signal application structure, a twelfth driving signal application structure, a fifth signal detection structure, and a sixth signal detection structure.

[0034] The ninth driving signal application structure, the tenth driving signal application structure, the eleventh driving signal application structure, and the twelfth driving signal application structure are symmetrically arranged inside the comb teeth of the third double-ended fixed resonant beam, and form a driving capacitor plate group by interlocking with the comb teeth.

[0035] The fifth signal detection structure and the sixth signal detection structure are symmetrically distributed on the outside of the comb teeth of the third double-ended fixed resonant beam. The comb teeth of the third double-ended fixed resonant beam form a detection capacitor plate group in an interlocking manner.

[0036] The fourth resonator includes a fourth resonator anchor point, a fourth double-ended fixed resonant beam, a thirteenth driving signal application structure, a fourteenth driving signal application structure, a fifteenth driving signal application structure, a sixteenth driving signal application structure, a seventh signal detection structure, an eighth signal detection structure, a ninth signal detection structure, a tenth signal detection structure, a first capacitor plate, a second capacitor plate, a third capacitor plate, and a fourth capacitor plate.

[0037] The thirteenth, fourteenth, fifteenth, and sixteenth driving signal application structures are symmetrically arranged inside the comb teeth of the fourth double-ended fixed resonant beam, and form a driving capacitor plate group by interlocking with the comb teeth.

[0038] The seventh signal detection structure, the eighth signal detection structure, the ninth signal detection structure, and the tenth signal detection structure are symmetrically distributed on the outside of the comb teeth of the fourth double-ended fixed resonant beam, and form a detection capacitor plate group with the comb teeth of the fourth double-ended fixed resonant beam in an interlocking manner.

[0039] Two sets of capacitor plates are symmetrically distributed on both sides of the fourth resonator. One set includes the first capacitor plate and the third capacitor plate, and the other set includes the second capacitor plate and the fourth capacitor plate. Both sets of capacitor plates are connected to the second load-bearing substrate.

[0040] The Y-axis force amplifying lever has the same structure as the X-axis force amplifying lever; the Y-axis force amplifying lever includes a first support anchor point, a first Y-axis force output straight beam, a first lever, and a first Y-axis force input straight beam.

[0041] The first support anchor point is used to provide fixed support and is structurally directly connected to the first lever to form a lever fulcrum;

[0042] The first Y-axis force output beam is located on the side of the first lever near the first support anchor point;

[0043] The first Y-axis force input beam is located at the end of the first lever away from the first support anchor point;

[0044] The first X-axis force output straight beam is positioned on the side of the second lever near the second support anchor point;

[0045] The first X-axis force input beam is located at the end of the second lever away from the second support anchor point;

[0046] The first Z-axis suppression structure, the second Z-axis suppression structure, the third Z-axis suppression structure, and the fourth Z-axis suppression structure are structurally identical.

[0047] The first, second, third, and fourth motion-restricting structures are structurally identical.

[0048] The first Z-axis suppression structure includes a first fixed anchor point, a first folded beam, and a second folded beam; wherein the first fixed anchor point is connected to the first folded beam and the second folded beam at 90° angles in the same plane.

[0049] The first motion-restricting structure includes a first restrictive anchor point and a first hook-shaped folding beam.

[0050] Usage: When the first load-bearing substrate is subjected to an externally applied acceleration in the Y-axis or X-axis direction, this external acceleration first forms an initial force at the input end of the first Y-axis force input beam of the Y-axis force amplification structure or X-axis force amplification structure. After the initial force is converted into energy by the Y-axis or X-axis force amplification structure, its amplitude is significantly amplified and transmitted to the single-end fixed resonant beam of the first or second resonator. Due to the increase in force amplitude, the effective stiffness of the first or second single-end fixed resonant beam changes accordingly. This stiffness change is synchronously coupled to the third double-end fixed resonant beam of the third resonator through the first or second coupling right-angle connection structure, causing the stiffness of the third double-end fixed resonant beam to also change synchronously. Therefore, the amplitude ratios of the first and second resonators, the first and third resonators, and the second and third resonators all produce changes in parameters such as eigenvalues ​​and eigenvectors. The vibration displacement of the four-degree-of-freedom weakly coupled resonant unit can be calculated using an external circuit. Through precise measurement and calculation, the acceleration amplitude corresponding to the external inertial force on the first load-bearing substrate can be derived in reverse. The fourth resonator employs the principle of electrostatic negative stiffness. By adjusting the change in electrostatic negative stiffness, changes in parameters such as eigenvalues ​​and eigenvectors are caused. The vibration displacement of the four-degree-of-freedom weakly coupled resonant unit is measured using an external circuit to achieve independent measurement of the Z-axis acceleration perpendicular to the device plane.

[0051] The present invention has the following advantages: Based on the collaborative design of orthogonally distributed resonant unit array and mechanical amplification mechanism, it uses a single sensitive element to achieve synchronous and accurate sensing of Y-axis, X-axis and Z-axis acceleration, breaking through the technical limitations of traditional single-axis detection mode, improving device space utilization and reducing the complexity of back-end signal processing circuits;

[0052] By employing a composite structure of four sets of symmetrical protection units and folded beams, and through stress distribution optimization and energy dissipation path design, the structural integrity of the device under mechanical shock or overload conditions is significantly enhanced, avoiding the breakage or plastic deformation of key resonant components and ensuring the long-term stability of the sensor in extreme environments.

[0053] Z-axis acceleration measurement utilizes electrostatic stiffness, which enables extremely sensitive responses to acceleration changes in the Z-axis direction, allowing even minute acceleration signals to be accurately captured with high signal conversion efficiency. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of the overall mechanical structure of the present invention.

[0055] Figure 2 This is a schematic diagram of the silicon micromechanical structure of the present invention.

[0056] Figure 3This is a schematic diagram of the first resonator, second resonator, third resonator, and fourth resonator of the present invention.

[0057] Figure 4 This is a schematic diagram of the Y-axis force amplification lever and the X-axis force amplification lever of the present invention.

[0058] Figure 5 This is a schematic diagram of the Z-axis suppression structure of the present invention.

[0059] Figure 6 This is a schematic diagram of the motion restriction structure of the present invention.

[0060] Explanation of reference numerals in the attached drawings: 1, first load-bearing substrate; 2, second load-bearing substrate; 3, occupying substrate;

[0061] 4-1, First resonator; 4-1-1, First single-ended fixed resonant beam; 4-1-2, First driving signal application structure; 4-1-3, Second driving signal application structure; 4-1-4, Third driving signal application structure; 4-1-5, Fourth driving signal application structure; 4-1-6, First signal detection structure; 4-1-7, Second signal detection structure;

[0062] 4-2, Second resonator; 4-2-1, Second single-ended fixed resonant beam; 4-2-2, Fifth driving signal application structure; 4-2-3, Sixth driving signal application structure; 4-2-4, Seventh driving signal application structure; 4-2-5, Eighth driving signal application structure; 4-2-6, Third signal detection structure; 4-2-7, Fourth signal detection structure;

[0063] 4-3, Third resonator; 4-3-1, Third double-ended fixed resonant beam; 4-3-2, Ninth driving signal application structure; 4-3-3, Tenth driving signal application structure; 4-3-4, Eleventh driving signal application structure; 4-3-5, Twelfth driving signal application structure; 4-3-6, Fifth signal detection structure; 4-3-7, Sixth signal detection structure; 4-3-8, Third resonator anchor point;

[0064] 4-4, Fourth resonator; 4-4-1, Fourth double-ended fixed resonant beam; 4-4-2, Thirteenth driving signal application structure; 4-4-3, Fourteenth driving signal application structure; 4-4-4, Fifteenth driving signal application structure; 4-4-5, Sixteenth driving signal application structure; 4-4-6, Seventh signal detection structure; 4-4-7, Eighth signal detection structure; 4-4-8, Ninth signal detection structure; 4-4-9, Tenth signal detection structure; 4-4-10, First capacitor plate; 4-4-11, Second capacitor plate; 4-4-12, Third capacitor plate; 4-4-13, Fourth capacitor plate; 4-4-14, Fourth resonator anchor point;

[0065] 5-1, Y-axis force amplification lever; 5-1-1, first support anchor point; 5-1-2, first Y-axis force output straight beam; 5-1-3, first lever; 5-1-4, first Y-axis force input straight beam;

[0066] 5-2, X-axis force amplification lever; 5-2-1, second support anchor point; 5-2-2, first X-axis force output straight beam; 5-2-3, second lever; 5-2-4, first X-axis force input straight beam;

[0067] 6-1, First Z-axis suppression structure; 6-1-1, First fixed anchor point; 6-1-2, First folded beam; 6-1-3, Second folded beam;

[0068] 6-2, Second Z-axis suppression structure; 6-2-1, Second fixed anchor point; 6-2-2, Third folded beam; 6-2-3, Fourth folded beam;

[0069] 6-3, Third Z-axis suppression structure; 6-3-1, Third fixed anchor point; 6-3-2, Fifth folded beam; 6-3-3, Sixth folded beam;

[0070] 6-4, Fourth Z-axis suppression structure; 6-4-1, Fourth fixed anchor point; 6-4-2, Seventh folded beam; 6-4-3, Eighth folded beam;

[0071] 7-1, First restrictive motion structure; 7-1-1, First restrictive fixed anchor point; 7-1-2, First hook-shaped folding beam;

[0072] 7-2, Second restrictive motion structure; 7-2-1, Second restrictive fixed anchor point; 7-2-2, Second hook-shaped folding beam;

[0073] 7-3, Third restrictive motion structure; 7-3-1, Third restrictive fixed anchor point; 7-3-2, Third hook-shaped folding beam;

[0074] 7-4, Fourth restrictive motion structure; 7-4-1, Fourth restrictive fixed anchor point; 7-4-2, Fourth hook-shaped folding beam;

[0075] 8-1, First coupling right-angle connection structure; 8-2, Second coupling right-angle connection structure; 8-3, Third coupling right-angle connection structure; 8-4, Fourth coupling right-angle connection structure; Detailed Implementation

[0076] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0077] like Figure 1As shown, this embodiment of the invention provides a triaxial accelerometer based on a four-degree-of-freedom weakly coupled resonator, which adopts a double-layer structure design. The upper layer is a micromechanical sensing element constructed from silicon, and the lower layer is a glass substrate made of silicon dioxide, which provides mechanical support and electrical isolation.

[0078] like Figure 2 As shown, the micromechanical sensing element includes a first force-bearing substrate 1, a second force-bearing substrate 2, a vacant substrate 3, a first resonator 4-1, a second resonator 4-2, a third resonator 4-3, a fourth resonator 4-4, a Y-axis force amplification lever 5-1, an X-axis force amplification lever 5-2, a first Z-axis suppression structure 6-1, a second Z-axis suppression structure 6-2, a third Z-axis suppression structure 6-3, a fourth Z-axis suppression structure 6-4, a first motion restriction structure 7-1, a second motion restriction structure 7-2, a third motion restriction structure 7-3, a fourth motion restriction structure 7-4, a first coupling right-angle connection structure 8-1, a second coupling right-angle connection structure 8-2, a third coupling right-angle connection structure 8-3, and a fourth coupling right-angle connection structure 8-4.

[0079] The first resonator 4-1 is mounted on the upper side of the first load-bearing substrate 1, and the second resonator 4-2 is located on the right side, with the two forming a 90° angle with each other. The third resonator 4-3 is located below the substrate, forming a 180° distribution with the first resonator 4-1. The fourth resonator 4-4 is located on the upper part of the substrate, forming a 180° angle with the second resonator 4-2. One end of the four resonators is rigidly connected through a common anchor point 2-5, forming a unified structural response reference.

[0080] The Y-axis force amplifying lever 5-1 is located on the upper side of the first load-bearing base 1, and the X-axis force amplifying lever 5-2 is located on the right side of the first load-bearing base 1; the first Z-axis suppression structure 6-1, the second Z-axis suppression structure 6-2, the third Z-axis suppression structure 6-3, and the fourth Z-axis suppression structure 6-4 are symmetrically arranged on the upper left, upper right, lower right, and lower left sides of the first load-bearing base 1, respectively; the first motion restriction structure 7-1, the second motion restriction structure 7-2, the third motion restriction structure 7-3, and the fourth motion restriction structure 7-4 are located on the upper left, upper right, lower right, and lower left sides of the second load-bearing base 2, respectively; the Y-axis force amplifying lever 5-1 is provided with a first Y-axis force input... The lever 5-2 has a first X-axis force input beam 5-1-4 and a first X-axis force output beam 5-1-2. The first resonator 4-1 is connected to the first Y-axis force output beam 5-1-2 on the Y-axis force amplifying lever 5-1, and the second resonator 4-2 is connected to the first X-axis force output beam 5-2-2 on the X-axis force amplifying lever 5-2. The first Y-axis force output beam 5-1-2 is used to transmit the force response to the first resonator 4-1. The X-axis force amplifying lever 5-2 has a first X-axis force output beam 5-2-2, which is connected to the second resonator.

[0081] The first Y-axis force input straight beam 5-1-4 and the first X-axis force input straight beam 5-2-4 are respectively connected to the upper left and lower right regions of the first load-bearing base 1.

[0082] The first folded beam 6-1-2 and the second folded beam 6-1-3 on the first Z-axis suppression structure 6-1, the third folded beam 6-2-2 and the fourth folded beam 6-2-3 on the second Z-axis suppression structure 6-2, the fifth folded beam 6-3-2 and the sixth folded beam 6-3-3 on the third Z-axis suppression structure 6-3, and the seventh folded beam 6-4-2 and the eighth folded beam 6-4-3 on the fourth Z-axis suppression structure 6-4 are all connected to the first load-bearing substrate 1.

[0083] The first hook-shaped folding beam 7-1-2 on the first restrictive motion structure 7-1, the second hook-shaped folding beam 7-2-2 on the second restrictive motion structure 7-2, the third hook-shaped folding beam 7-3-2 on the third restrictive motion structure 7-3, and the fourth hook-shaped folding beam 7-4-2 on the fourth restrictive motion structure 7-4 are all connected to the second load-bearing base 2.

[0084] One end of the first coupling right-angle connection structure 8-1 is connected to the first single-end fixed resonant beam 4-1-1 in the first resonator 4-1, and the other end is connected to the fourth double-end fixed resonant beam 4-4-1 in the fourth resonator 4-4.

[0085] The second coupling right-angle connection structure 8-2 is used to connect the first single-end fixed resonant beam 4-1-1 of the first resonator 4-1 and the second single-end fixed resonant beam 4-2-1 of the second resonator 4-2.

[0086] The third coupling right-angle connection structure 8-3 connects the second single-end fixed resonant beam 4-2-1 of the second resonator 4-2 and the third double-end fixed resonant beam 4-3-1 of the third resonator 4-3.

[0087] The fourth coupling right-angle connection structure 8-4 connects the third double-ended fixed resonant beam 4-3-1 of the third resonator 4-3 to the fourth double-ended fixed resonant beam 4-4-1 of the fourth resonator 4-4.

[0088] like Figure 3 As shown, the first resonator 4-1 and the second resonator 4-2 have completely identical structures. The first resonator 4-1 is composed of a first single-end fixed resonant beam 4-1-1, a first driving signal application structure 4-1-2, a second driving signal application structure 4-1-3, a third driving signal application structure 4-1-4, a fourth driving signal application structure 4-1-5, a first signal detection structure 4-1-6, and a second signal detection structure 4-1-7.

[0089] The first driving signal application structure 4-1-2, the second driving signal application structure 4-1-3, the third driving signal application structure 4-1-4, and the fourth driving signal application structure 4-1-5 are symmetrically arranged inside the comb teeth of the first single-end fixed resonant beam 4-1-1, and form a driving capacitor plate group by interlocking with its comb teeth.

[0090] The first signal detection structure 4-1-6 and the second signal detection structure 4-1-7 are symmetrically distributed on the outside of the comb teeth of the first single-end fixed resonant beam 4-1-1, and form a detection capacitor plate group with the comb teeth of the first single-end fixed resonant beam 4-1-1 in an interlocking manner.

[0091] The second resonator 4-2 consists of a second single-ended fixed resonant beam 4-2-1, a fifth driving signal application structure 4-2-2, a sixth driving signal application structure 4-2-3, a seventh driving signal application structure 4-2-4, an eighth driving signal application structure 4-2-5, a third signal detection structure 4-2-6, and a fourth signal detection structure 4-2-7. The fifth driving signal application structure 4-2-2, the sixth driving signal application structure 4-2-3, the seventh driving signal application structure 4-2-4, and the eighth driving signal application structure 4-2-5 are symmetrically arranged inside the comb teeth of the second single-ended fixed resonant beam 4-2-1, and form a driving capacitor plate group by interlocking with the comb teeth. The third signal detection structure 4-2-6 and the fourth signal detection structure 4-2-7 are symmetrically distributed outside the comb teeth of the second single-ended fixed resonant beam 4-2-1, and the comb teeth of the second single-ended fixed resonant beam 4-2-1 form a detection capacitor plate group by interlocking.

[0092] The third resonator 4-3 consists of a third resonator anchor point 4-3-8, a third double-ended fixed resonant beam 4-3-1, a ninth driving signal application structure 4-3-2, a tenth driving signal application structure 4-3-3, an eleventh driving signal application structure 4-3-4, a twelfth driving signal application structure 4-3-5, a fifth signal detection structure 4-3-6, and a sixth signal detection structure 4-3-7. The ninth driving signal application structure 4-3-2, the tenth driving signal application structure 4-3-3, the eleventh driving signal application structure 4-3-4, and the twelfth driving signal application structure 4-3-5 are symmetrically arranged inside the comb teeth of the third double-ended fixed resonant beam 4-3-1, and form a driving capacitor plate group by interlocking with the comb teeth. The fifth signal detection structure 4-3-6 and the sixth signal detection structure 4-3-7 are symmetrically distributed outside the comb teeth of the third double-ended fixed resonant beam 4-3-1, and the comb teeth of the third double-ended fixed resonant beam 4-3-1 form a detection capacitor plate group by interlocking.

[0093] The fourth resonator 4-4 consists of the fourth resonator anchor point 4-4-14, the fourth double-ended fixed resonant beam 4-4-1, the thirteenth driving signal application structure 4-4-2, the fourteenth driving signal application structure 4-4-3, the fifteenth driving signal application structure 4-4-4, the sixteenth driving signal application structure 4-4-5, the seventh signal detection structure 4-4-6, the eighth signal detection structure 4-4-7, the ninth signal detection structure 4-4-8, the tenth signal detection structure 4-4-9, the first capacitor plate 4-4-10, the second capacitor plate 4-4-11, the third capacitor plate 4-4-12, and the fourth capacitor plate 4-4-13; the thirteenth driving signal... The application structures 4-4-2, 4-4-3, 4-4-4, and 4-4-5 are symmetrically arranged inside the comb teeth of the fourth double-ended fixed resonant beam 4-4-1, forming a driving capacitor plate group by interlocking with the comb teeth. The seventh signal detection structure 4-4-6, 4-4-7, 4-4-8, and 4-4-9 are symmetrically distributed outside the comb teeth of the fourth double-ended fixed resonant beam 4-4-1, forming a detection capacitor plate group by interlocking with the comb teeth of the fourth double-ended fixed resonant beam 4-4-1.

[0094] Two sets of capacitor plates are symmetrically distributed on both sides of the resonator. One set includes a first capacitor plate 4-4-10 and a third capacitor plate 4-4-12, and the other set includes a second capacitor plate 4-4-11 and a fourth capacitor plate 4-4-13. Both sets of capacitor plates are connected to the second load-bearing substrate 2.

[0095] like Figure 4 As shown, the Y-axis force amplifying lever 5-1 and the X-axis force amplifying lever 5-2 have the same structure and use the same component configuration and connection method. The Y-axis force amplifying lever 5-1 is composed of a first support anchor point 5-1-1, a first Y-axis force output straight beam 5-1-2, a first lever 5-1-3, and a first Y-axis force input straight beam 5-1-4.

[0096] The first support anchor point 5-1-1 provides fixed support and is structurally directly connected to the first lever 5-1-3, forming a lever fulcrum. The first Y-axis force output beam 5-1-2 is located on the side of the first lever 5-1-3 near the first support anchor point 5-1-1, and the output force is transmitted through the first Y-axis force output beam 5-1-2; while the first Y-axis force input beam 5-1-4 is located at the end of the first lever 5-1-3 away from the first support anchor point 5-1-1; the first X-axis force output beam 5-2-2 is located on the side of the second lever 5-2-3 near the second support anchor point 5-2-1; the first X-axis force input beam 5-2-4 is located at the end of the second lever 5-2-3 away from the second support anchor point 5-2-1.

[0097] like Figure 5 As shown, the first Z-axis suppression structure 6-1, the second Z-axis suppression structure 6-2, the third Z-axis suppression structure 6-3, and the fourth Z-axis suppression structure 6-4 are completely identical; the first motion restriction structure 7-1, the second motion restriction structure 7-2, the third motion restriction structure 7-3, and the fourth motion restriction structure 7-4 are also completely identical.

[0098] like Figure 6 As shown, the first Z-axis suppression structure 6-1 is composed of a first fixed anchor point 6-1-1, a first folded beam 6-1-2, and a second folded beam 6-1-3; the second Z-axis suppression structure 6-2 is composed of a second fixed anchor point 6-2-1, a third folded beam 6-2-2, and a fourth folded beam 6-2-3; the third Z-axis suppression structure 6-3 is composed of a third fixed anchor point 6-3-1, a fifth folded beam 6-3-2, and a sixth folded beam 6-3-3; and the fourth Z-axis suppression structure 6-4 is composed of a first fixed anchor point 6-4-1, a seventh folded beam 6-4-2, and an eighth folded beam 6-4-3.

[0099] The first motion-restricting structure 7-1 consists of a first restrictive anchor point 7-1-1 and a first hook-shaped folding beam 7-1-2; the second motion-restricting structure 7-2 consists of a second restrictive anchor point 7-2-1 and a second hook-shaped folding beam 7-2-2; the third motion-restricting structure 7-3 consists of a third restrictive anchor point 7-3-1 and a third hook-shaped folding beam 7-3-2; and the fourth motion-restricting structure 7-4 consists of a fourth restrictive anchor point 7-4-1 and a fourth hook-shaped folding beam 7-4-2.

[0100] This invention provides a triaxial accelerometer based on a four-degree-of-freedom weakly coupled resonator. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment of the invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention. All components not explicitly stated in this embodiment can be implemented using existing technologies.

Claims

1. A triaxial accelerometer based on a four-degree-of-freedom weakly coupled resonator, characterized in that, It includes an upper and lower double-layer structure, wherein the upper layer is a micromechanical sensing element constructed from silicon, and the lower layer is a glass base made of silicon dioxide. The glass base is used to provide mechanical support and electrical isolation. The micromechanical sensing element includes a first force-bearing substrate (1), a second force-bearing substrate (2), a vacant substrate (3), a first resonator (4-1), a second resonator (4-2), a third resonator (4-3), a fourth resonator (4-4), a Y-axis force amplification lever (5-1), an X-axis force amplification lever (5-2), a first Z-axis suppression structure (6-1), a second Z-axis suppression structure (6-2), a third Z-axis suppression structure (6-3), a fourth Z-axis suppression structure (6-4), a first motion restriction structure (7-1), a second motion restriction structure (7-2), a third motion restriction structure (7-3), a fourth motion restriction structure (7-4), a first coupling right-angle connection structure (8-1), a second coupling right-angle connection structure (8-2), a third coupling right-angle connection structure (8-3), and a fourth coupling right-angle connection structure (8-4). The first resonator (4-1) is installed on the upper side of the first load-bearing base (1), and the second resonator (4-2) is disposed on the right side of the first load-bearing base (1). The first resonator (4-1) and the second resonator (4-2) are arranged at a 90° angle to each other. The third resonator (4-3) is located below the first load-bearing substrate (1) and forms a 180° distribution relationship with the first resonator (4-1); The fourth resonator (4-4) is disposed on the upper part of the first load-bearing substrate (1) and is disposed at a 180° angle with the second resonator (4-2); One end of the first resonator (4-1), the second resonator (4-2), the third resonator (4-3), and the fourth resonator (4-4) are rigidly connected through a common anchor point. The other end of the first resonator (4-1) is connected to the Y-axis force amplification lever (5-1), the other end of the second resonator (4-2) is connected to the X-axis force amplification lever (5-2), the other end of the third resonator (4-3) is connected to the third resonator anchor point (4-3-8), and the other end of the fourth resonator (4-4) is connected to the fourth resonator anchor point (4-4-14). The Y-axis force amplification lever (5-1) is located on the upper side of the first force-bearing base (1), and the X-axis force amplification lever (5-2) is located on the right side of the first force-bearing base (1); The first Z-axis suppression structure (6-1), the second Z-axis suppression structure (6-2), the third Z-axis suppression structure (6-3), and the fourth Z-axis suppression structure (6-4) are symmetrically arranged on the upper left, upper right, lower right, and lower left sides of the first load-bearing substrate (1), respectively. The first restricting motion structure (7-1), the second restricting motion structure (7-2), the third restricting motion structure (7-3), and the fourth restricting motion structure (7-4) are located on the upper left, upper right, lower right, and lower left sides of the second load-bearing base (2), respectively. The Y-axis force amplification lever (5-1) is provided with a first Y-axis force output straight beam (5-1-2) and a first Y-axis force input straight beam (5-1-4). The X-axis force amplification lever (5-2) is provided with a first X-axis force output straight beam (5-2-2) and a first X-axis force input straight beam (5-2-4). The first resonator (4-1) is connected to the first Y-axis force output straight beam (5-1-2), and the second resonator (4-2) is connected to the first X-axis force output straight beam (5-2-2). The first Y-axis force input straight beam (5-1-4) and the first X-axis force input straight beam (5-2-4) are respectively connected to the upper left and lower right regions of the first load-bearing base (1); The first resonator (4-1) includes a first single-ended fixed resonant beam (4-1-1); the second resonator (4-2) includes a second single-ended fixed resonant beam (4-2-1); and the third resonator (4-3) includes a third double-ended fixed resonant beam (4-3-1). One end of the first coupling right-angle connection structure (8-1) is connected to the first single-end fixed resonant beam (4-1-1), and the other end is connected to the fourth double-end fixed resonant beam (4-4-1); The second coupling right-angle connection structure (8-2) is used to connect the first single-end fixed resonant beam (4-1-1) and the second single-end fixed resonant beam (4-2-1). The third coupling right-angle connection structure (8-3) connects the second single-end fixed resonant beam (4-2-1) and the third double-end fixed resonant beam (4-3-1) respectively. The fourth coupling right-angle connection structure (8-4) connects the third double-ended fixed resonant beam (4-3-1) and the fourth double-ended fixed resonant beam (4-4-1) respectively.

2. A triaxial accelerometer based on a four-degree-of-freedom weakly coupled resonator according to claim 1, characterized in that, The first Z-axis suppression structure (6-1) is provided with a first folded beam (6-1-2) and a second folded beam (6-1-3). The second Z-axis suppression structure (6-2) is provided with a third folded beam (6-2-2) and a fourth folded beam (6-2-3); The third Z-axis suppression structure (6-3) is provided with a fifth folded beam (6-3-2) and a sixth folded beam (6-3-3). The fourth Z-axis suppression structure (6-4) is provided with a seventh folded beam (6-4-2) and an eighth folded beam (6-4-3). The first folded beam (6-1-2), the second folded beam (6-1-3), the third folded beam (6-2-2), the fourth folded beam (6-2-3), the fifth folded beam (6-3-2), the sixth folded beam (6-3-3), the seventh folded beam (6-4-2), and the eighth folded beam (6-4-3) are all connected to the first load-bearing substrate (1).

3. A triaxial accelerometer based on a four-degree-of-freedom weakly coupled resonator according to claim 2, characterized in that, The first motion-restricting structure (7-1) is provided with a first hook-shaped folding beam (7-1-2), the second motion-restricting structure (7-2) is provided with a second hook-shaped folding beam (7-2-2), the third motion-restricting structure (7-3) is provided with a third hook-shaped folding beam (7-3-2), and the fourth motion-restricting structure (7-4) is provided with a fourth hook-shaped folding beam (7-4-2). The first hook-shaped folding beam (7-1-2), the second hook-shaped folding beam (7-2-2), the third hook-shaped folding beam (7-3-2) and the fourth hook-shaped folding beam (7-4-2) are all connected to the second load-bearing base (2).

4. A triaxial accelerometer based on a four-degree-of-freedom weakly coupled resonator according to claim 3, characterized in that, The first resonator (4-1) has the same structure as the second resonator (4-2). The first resonator (4-1) includes a first single-ended fixed resonant beam (4-1-1), a first driving signal application structure (4-1-2), a second driving signal application structure (4-1-3), a third driving signal application structure (4-1-4), a fourth driving signal application structure (4-1-5), a first signal detection structure (4-1-6), and a second signal detection structure (4-1-7). The first driving signal application structure (4-1-2), the second driving signal application structure (4-1-3), the third driving signal application structure (4-1-4), and the fourth driving signal application structure (4-1-5) are symmetrically arranged inside the comb teeth of the first single-end fixed resonant beam (4-1-1), and form a driving capacitor plate group by interlocking with the comb teeth. The first signal detection structure (4-1-6) and the second signal detection structure (4-1-7) are symmetrically distributed on the outside of the comb teeth of the first single-end fixed resonant beam (4-1-1), and form a detection capacitor plate group with the comb teeth of the first single-end fixed resonant beam (4-1-1) in an interlocking manner. The third resonator (4-3) includes a third resonator anchor point (4-3-8), a third double-ended fixed resonator beam (4-3-1), a ninth driving signal application structure (4-3-2), a tenth driving signal application structure (4-3-3), an eleventh driving signal application structure (4-3-4), a twelfth driving signal application structure (4-3-5), a fifth signal detection structure (4-3-6), and a sixth signal detection structure (4-3-7). The ninth driving signal application structure (4-3-2), the tenth driving signal application structure (4-3-3), the eleventh driving signal application structure (4-3-4), and the twelfth driving signal application structure (4-3-5) are symmetrically arranged inside the comb teeth of the third double-ended fixed resonant beam (4-3-1), and form a driving capacitor plate group by interlocking with the comb teeth. The fifth signal detection structure (4-3-6) and the sixth signal detection structure (4-3-7) are symmetrically distributed on the outside of the comb teeth of the third double-ended fixed resonant beam (4-3-1), and the comb teeth of the third double-ended fixed resonant beam (4-3-1) form a detection capacitor plate group in an interlocking manner. The fourth resonator (4-4) includes a fourth resonator anchor point (4-4-14), a fourth double-ended fixed resonant beam (4-4-1), a thirteenth driving signal application structure (4-4-2), a fourteenth driving signal application structure (4-4-3), a fifteenth driving signal application structure (4-4-4), a sixteenth driving signal application structure (4-4-5), a seventh signal detection structure (4-4-6), an eighth signal detection structure (4-4-7), a ninth signal detection structure (4-4-8), a tenth signal detection structure (4-4-9), a first capacitor plate (4-4-10), a second capacitor plate (4-4-11), a third capacitor plate (4-4-12), and a fourth capacitor plate (4-4-13). The thirteenth driving signal application structure (4-4-2), the fourteenth driving signal application structure (4-4-3), the fifteenth driving signal application structure (4-4-4), and the sixteenth driving signal application structure (4-4-5) are symmetrically arranged inside the comb teeth of the fourth double-ended fixed resonant beam (4-4-1), and form a driving capacitor plate group by interlocking with the comb teeth. The seventh signal detection structure (4-4-6), the eighth signal detection structure (4-4-7), the ninth signal detection structure (4-4-8), and the tenth signal detection structure (4-4-9) are symmetrically distributed on the outside of the comb teeth of the fourth double-ended fixed resonant beam (4-4-1), and form a detection capacitor plate group with the comb teeth of the fourth double-ended fixed resonant beam (4-4-1) in an interlocking manner. Two sets of capacitor plates are symmetrically distributed on both sides of the fourth resonator (4-4). One set includes the first capacitor plate (4-4-10) and the third capacitor plate (4-4-12), and the other set includes the second capacitor plate (4-4-11) and the fourth capacitor plate (4-4-13). Both sets of capacitor plates are connected to the second load-bearing substrate (2). The Y-axis force amplifying lever (5-1) has the same structure as the X-axis force amplifying lever (5-2); the Y-axis force amplifying lever (5-1) includes a first support anchor point (5-1-1), a first Y-axis force output straight beam (5-1-2), a first lever (5-1-3), and a first Y-axis force input straight beam (5-1-4). The first support anchor point (5-1-1) is used to provide fixed support and is structurally directly connected to the first lever (5-1-3) to form a lever fulcrum; The first Y-axis force output straight beam (5-1-2) is located on the side of the first lever (5-1-3) near the first support anchor point (5-1-1); The first Y-axis force input straight beam (5-1-4) is located at the end of the first lever (5-1-3) away from the first support anchor point (5-1-1); The first X-axis force output straight beam (5-2-2) is set on the side of the second lever (5-2-3) near the second support anchor point (5-2-1); The first X-axis force input straight beam (5-2-4) is located at the end of the second lever (5-2-3) away from the second support anchor point (5-2-1); The first Z-axis suppression structure (6-1), the second Z-axis suppression structure (6-2), the third Z-axis suppression structure (6-3), and the fourth Z-axis suppression structure (6-4) have the same structure; The first motion restriction structure (7-1), the second motion restriction structure (7-2), the third motion restriction structure (7-3), and the fourth motion restriction structure (7-4) have the same structure; The first Z-axis suppression structure (6-1) includes a first fixed anchor point (6-1-1), a first folded beam (6-1-2), and a second folded beam (6-1-3); wherein the first fixed anchor point (6-1-1) is connected to the first folded beam (6-1-2) and the second folded beam (6-1-3) at 90° angles in the same plane. The first motion-restricting structure (7-1) includes a first restricting fixed anchor point (7-1-1) and a first hook-shaped folding beam (7-1-2).

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