Gyroscope detection structure, gyroscope and method for detecting angular velocity

Abstract

The invention discloses a gyroscope detection structure, a gyroscope and a method for detecting angular velocity, the gyroscope detection structure is divided into four detection areas which are mutually symmetrical up and down and left and right through an x-axis of symmetry and a y-axis of symmetry which are perpendicular to each other, and the four detection areas are defined as a first detection area, a second detection area, a third detection area and a fourth detection area; each detection area comprises at least two comb capacitor banks, at least four driving beams, at least one driving mass block, at least four H-shaped detection beams and at least one Coriolis mass block; the gyroscope is formed by bonding a device wafer and a cap wafer, the method is applied to the gyroscope, a compact four-mass tuning fork structure is adopted, the four mass blocks are distributed in a central symmetry mode, when external vibration and impact are generated to cause displacement, the displacement can be offset in the four mass blocks, and compared with a traditional gyroscope with a single mass block and a traditional gyroscope with double mass blocks, the method has the advantages of being simple in structure and convenient to operate. The four-mass-block gyroscope has more excellent performance in indexes such as sensitivity, stability, interference resistance and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of gyroscopes, and particularly to a gyro detection structure, a gyroscope, and a method for detecting angular velocity. Background Art

[0002] In the era of rapid technological development, microelectromechanical systems have become the core technological force in the modern sensor field due to their excellent low-power consumption and miniaturization advantages. With the booming rise of the Internet of Things, intelligent devices, and cutting-edge national defense technologies, higher requirements have been put forward for the accuracy, reliability, and integration of sensors. MEMS technology, with its unique technical characteristics, perfectly meets these development needs and occupies a crucial position in the sensor market. As a typical application product of the technology, silicon micro-machined gyroscopes undertake the key mission of measuring the angular velocity or angle of the carrier relative to the inertial space. In the aviation field, it provides accurate angle data for the attitude control of aircraft, ensuring the stability of the aircraft under complex weather conditions and high-speed flight; in space exploration, it helps satellites achieve precise orbit adjustment and attitude calibration, ensuring the smooth progress of communication and remote sensing tasks; in intelligent navigation systems, whether it is an autonomous driving vehicle or a handheld navigation device, silicon micro-machined gyroscopes play an indispensable role. The common detection methods of gyroscopes are mainly divided into optical and capacitive. Optical gyroscopes were once favored in some special fields with extremely high requirements for measurement accuracy due to their high precision. However, their complex technical architecture brings many limitations. To achieve optical detection, a precise optical path space needs to be carefully designed. From the emission, conduction to the reception of light, each link requires high-precision components and strict spatial layout, which makes the overall structure extremely complex and increases the difficulty of design and manufacturing. At the same time, the use of high-precision optical devices not only significantly raises the production cost but also makes the quality control during the production process extremely difficult, and the yield rate is difficult to be effectively guaranteed. In addition, optical gyroscopes rely on specific lasers as light sources. The energy consumption of the lasers significantly increases the overall power consumption of the system, and the working stability of the lasers is easily affected by environmental factors, thus reducing the reliability and stability of the entire system. Compared with optical gyroscopes, capacitive gyroscopes exhibit unique technical advantages. Its structural design is relatively simple, which creates favorable conditions for large-scale industrial production. Through standardized production processes and processes, it can effectively reduce product costs and improve production efficiency. The good compatibility of capacitive gyroscopes with IC circuits enables them to be easily integrated into various electronic systems to achieve a high degree of system integration. What is more worth mentioning is that capacitive gyroscopes have strong environmental adaptability. Whether it is in harsh environments such as high temperature, low temperature, high humidity, or complex electromagnetic environments such as strong electromagnetic interference, it can maintain stable performance output, which makes it have extremely high market value and application potential in a wide range of fields such as industrial automation, automotive electronics, and consumer electronics. The working principle of the capacitive gyroscope is based on the famous Coriolis effect. When the gyroscope enters the working state, it first applies a vibration of a specific frequency in the driving direction, laying the foundation for detecting angular velocity. When there is an angular velocity input along the axis, according to the Coriolis effect, a Coriolis force will be generated in the detection axis direction. This tiny Coriolis force will cause the Coriolis mass block to displace in the detection axis direction, and the change in the displacement of the Coriolis mass block is closely related to the magnitude of the input angular velocity. By capturing and analyzing these displacement changes through a high-precision detection circuit, the information of the input angular velocity can be accurately obtained, thereby realizing the angular velocity measurement function.

[0003] However, the traditional x-axis gyroscope currently faces a series of technical challenges that need to be solved in practical applications. In terms of detection sensitivity, when the x-axis gyroscope works normally, the Coriolis mass block will displace along the z-axis direction. Under conventional detection methods, the Coriolis mass block will inevitably be affected by a large squeeze film damping. Squeeze film damping is the resistance generated by the interaction between the mass block and the surrounding air during movement. It consumes the kinetic energy of the mass block, making the displacement response of the mass block slow, which in turn seriously affects the gyroscope's detection sensitivity to small angular velocity changes, resulting in reduced accuracy of the measurement results.

[0004] From the perspective of detection mode accuracy, when the gyro is working, the driving mode and the detection mode will produce coupling. Since the displacement amplitude of the driving mode is large, once it is coupled with the detection mode, it will cause strong interference to the detection mode. This interference will cause a large amount of noise to be mixed into the detection signal, making it difficult for the detection circuit to accurately distinguish the real detection signal, which will seriously affect the accuracy of the gyro detection mode and cause large errors in the measurement results. In terms of multi-mass differential detection, when the gyro structure uses multiple masses for differential detection, there is a problem that the stiffness is the same when driving in the same and opposite modes. Due to the same stiffness, it is difficult to effectively distinguish these two modes from the mechanical characteristics, which makes the detection circuit unable to accurately identify the signal characteristics in different modes and affects the effect of differential detection. At present, gyros with multi-mass differential detection methods often use U-shaped beams as driving coupling beams, attempting to distinguish between the same and opposite driving modes by suppressing the reverse mode. However, while this U-shaped beam structure suppresses the reverse mode, it introduces the same mode as a low-order interference mode into the system. These low-order interference modes will generate additional vibrations and noises during the operation of the gyro, interfering with the normal detection signal and affecting the normal operation of the gyro. In the detection direction, there are similar problems, further reducing the detection accuracy.

[0005] Frequency control is also a major challenge faced by traditional x-axis gyros. It is difficult to precisely control the frequency difference between the structure driving frequency and the detection frequency, and this frequency difference has a crucial impact on the sensitivity of the gyro. If the frequency difference is too large or too small, it will lead to a decrease in the signal response ability of the detection circuit, unable to accurately capture the weak signal corresponding to the displacement change of the mass, thus affecting the overall performance and measurement accuracy of the gyro. In addition, the Coriolis masses of tuning fork gyros are relatively independent. During the production and processing process, due to factors such as process errors and material property differences, different Coriolis masses will be affected by different degrees of processing errors. These processing errors will cause differences in the physical properties such as the mass and stiffness of the Coriolis masses. Under the action of the same external force, the displacements of the Coriolis masses will also be inconsistent. This displacement difference will be directly reflected in the signal output, making the output signal contain a large amount of error components, seriously reducing the reliability and accuracy of the gyro measurement results. In summary, the many problems exposed by traditional x-axis gyros in practical applications severely restrict their further development and application in the fields of high precision and high reliability. Therefore, developing a new type of gyro structure that can effectively resist the interference of the same mode and has high integration has become a key topic that urgently needs to be overcome in the current gyro technology field, which has important practical significance for promoting the wide application and innovative development of the technology in more fields. Summary of the Invention

[0006] The object of the present invention is to provide a gyroscope detection structure, a gyroscope, and a method for detecting angular velocity, so as to solve the above problems such as the tuning fork type x-axis gyroscope being vulnerable to co-directional mode interference. At the same time, in order to further improve the sensitivity, integration, and stability of the gyroscope. The present invention provides the following technical solution: a gyroscope detection structure, which is divided into four detection areas that are symmetric with each other up, down, left, and right by an x symmetry axis and a y symmetry axis that are perpendicular to each other, and are defined as the first detection area, the second detection area, the third detection area, and the fourth detection area; The first detection area and the second detection area, and the third detection area and the fourth detection area are respectively connected by corresponding diamond-shaped series drive coupling beam mechanisms: The first detection area and the third detection area, and the second detection area and the fourth detection area are respectively connected by corresponding lever parallel drive coupling beams; Each of the detection areas includes: At least two comb-shaped capacitor groups, which are connected to an electrical signal; At least four drive beams, and each of the drive beams is installed on a corresponding comb-shaped capacitor group; At least one drive mass block, and both ends of the drive mass block are respectively connected to two drive beams; At least two H-shaped detection beams; At least one Coriolis mass block, which is installed on the gyroscope detection structure through a corresponding detection coupling beam: One end of the H-shaped detection beam is connected to the drive mass block, and the other end is connected to the Coriolis mass block; Among them, after receiving the electrical signal, the comb-shaped capacitor group drives the periodic movement of the comb teeth, and further drives the periodic movement of the drive mass block on the drive beam; The drive mass blocks in the first detection area and the drive mass blocks in the second detection area move in opposite directions; the drive mass blocks in the third detection area and the drive mass blocks in the fourth detection area move in opposite directions.

[0007] Furthermore, the comb-shaped capacitor group is composed of a drive positive comb tooth, a drive detection comb tooth positive electrode, a drive detection comb tooth negative electrode, and a drive negative comb tooth arranged from top to bottom along the y-axis direction.

[0008] Furthermore, the diamond-shaped series drive coupling beam mechanism is composed of a group of mutually parallel cantilever beams and a diamond-shaped deformation frame located between the cantilever beams; Furthermore, the upper and lower vertices of the diamond-shaped deformation frame are connected to the corresponding drive mass blocks.

[0009] The present invention provides the following technical solution: a gyroscope, which is formed by bonding a device wafer and a cap wafer; The device wafer includes a device cavity layer and an etching layer having the above-mentioned gyroscope detection structure; Furthermore, the cap wafer includes: at least a plurality of anchor points for fixing the etching layer on the cap wafer and providing electrical signals to the comb capacitor bank through the anchor points; Cap wafer cavity layer; At least four detection electrode plates located on the cap wafer cavity layer directly below the corresponding Coriolis mass blocks; At least four orthogonal compensation electrode plates located on the cap wafer cavity layer directly below the corresponding Coriolis mass blocks and each independently controlled; the orthogonal compensation electrode plates are used to add orthogonal compensation electrodes in the detection direction of the gyroscope, and by controlling the current of the orthogonal compensation electrode plates, an electrostatic force is generated on the Coriolis mass blocks, so that the Coriolis mass blocks at both ends of the lever coupling beam are maintained in the same state; Furthermore, the Coriolis mass blocks in the first detection area and the Coriolis mass blocks in the fourth detection area move in the same direction and are connected in series with the corresponding detection electrode plates; The Coriolis mass blocks in the second detection area and the Coriolis mass blocks in the third detection area move in the same direction and are connected in series with the corresponding detection electrode plates.

[0010] One of the technical solutions provided by the present invention is: a method for a gyroscope to detect angular velocity, which is applied to the above gyroscope, and the method includes: S1. When the gyroscope is in the working state, drive the drive positive comb teeth and drive negative comb teeth on both sides of the drive mass block to drive the drive mass block to perform periodic motion along the y-axis.

[0011] S2. There is a rigid connection between the drive mass block and the corresponding Coriolis mass block, and the Coriolis mass block 11 performs periodic motion along the drive direction; S3. When the series-connected drive mass blocks move in opposite directions, the drive mass blocks 9 on both sides drive the rhombic deformation frame to change, causing the cantilever beams on both sides to displace in the x-axis direction, reducing the influence on the stiffness of the gyroscope; S4. Under the combined action of the rhombic series drive coupling beam mechanism and the lever parallel drive coupling beam, adjacent drive mass blocks perform equal and opposite motions, reducing the influence of common-mode noise on the drive displacement output of the drive mass blocks; S5. When the gyroscope rotates along the x-axis direction at a specified angular rate, the Coriolis mass blocks move along the z-axis direction under the action of the Coriolis force; S6. The Coriolis mass blocks and the corresponding detection electrode plates form a capacitance change amount, and by detecting the capacitance change amount, the torsion angle of the Coriolis mass blocks is obtained.

[0012] S7. According to the gyro detection displacement formula, the torsional angle of the Coriolis mass block is positively correlated with the input angular velocity of the gyroscope. By detecting the capacitance change between the four Coriolis mass blocks and the detection electrode plates, the angular velocity input to the gyroscope can be obtained.

[0013] Further, the method further includes: when the initial position of the Coriolis mass block is not zero, the orthogonal compensation electrode is used to control the orthogonal compensation plate current to generate an electrostatic force on the Coriolis mass block, so that the Coriolis mass blocks at both ends of the lever coupling beam are maintained in the same state, and the influence of reducing the orthogonal error on the device is completed.

[0014] In the above technical solution, a four-mass tuning fork structure is adopted, and the four mass blocks are symmetrically distributed around the center. When external vibrations and impacts cause displacements, they can cancel each other out among the four mass blocks. Compared with traditional single-mass and double-mass gyroscopes, the four-mass block gyroscope has better performance in terms of sensitivity, stability, anti-interference and other indicators.

[0015] In this solution, the movement of the Coriolis mass block is a double-door swinging pendulum movement mode. Compared with the traditional out-of-plane movement mode, the swinging pendulum structure is less affected by the squeeze film resistance; since the test torsional angle in the detection direction does not interfere with the driving direction, the decoupling of the driving mass block and the Coriolis mass block is realized; for the double-door differential swinging pendulum movement structure, compared with the traditional swinging pendulum structure, the H-shaped detection beam is located at the edge of the mass block, and the detection area is larger, which is beneficial to further improving the gyro sensitivity.

[0016] In this solution, the adjacent Coriolis mass blocks are connected by a lever parallel drive coupling beam. Compared with the traditional structure, this structure suppresses the same-direction movement of the Coriolis mass block in the z-axis; by controlling the width of the torsion axis of the detection coupling beam, the detection frequency can be controlled without affecting the driving frequency, and a high-performance gyro structure can be obtained by controlling the frequency difference between the driving frequency and the detection frequency.

[0017] In this solution, in the detection direction, by adjusting the electrical signal of the orthogonal feedback electrode plate, the influence of the orthogonal error on the device is reduced, the yield of the structure is improved; at the same time, the difficulty of signal processing is reduced, and the gyro performance is comprehensively improved.

[0018] The drive structure of this solution adopts a semi-frame structure. Compared with the traditional structure, this structure can effectively increase the area of the Coriolis mass block and improve the detection sensitivity of the gyroscope. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings.

[0020] Figure 1 This is a schematic structural diagram of the gyroscope detection structure in the present invention.

[0021] Figure 2 This is a schematic structural diagram of the comb-tooth capacitor bank in the present invention.

[0022] Figure 3 This is a schematic diagram of the working motion process of the gyroscope detection structure in the present invention.

[0023] Figure 4 This is a schematic structural diagram of the gyroscope in the present invention.

[0024] Figure 5 This is a schematic diagram of the process of the gyroscope driving in the same direction (where y is the displacement of the driving mass; K1 is the stiffness in the driving direction; K2 is the stiffness of the driving in-phase coupler; K3 is the stiffness of the driving anti-phase coupler; c is the damping magnitude).

[0025] Figure 6 This is a schematic diagram of the process of the gyroscope driving in the opposite direction (where y is the displacement of the driving mass; K1 is the stiffness in the driving direction; K2 is the stiffness of the driving in-phase coupler; K3 is the stiffness of the driving anti-phase coupler; c is the damping magnitude).

[0026] Figure 7 This is a schematic diagram of the operation of the orthogonal compensation electrode plate in the present invention.

[0027] Figure 8 This is a schematic diagram of the operation when the series-connected driving mass blocks displace in the same direction.

[0028] Figure 9 This is a schematic diagram of the operation when the series-connected driving mass blocks displace in the opposite direction.

[0029] Figure 10 This is a schematic diagram of the operation when the parallel-connected driving mass blocks displace in the same direction.

[0030] Figure 11 This is a schematic diagram of the operation when the parallel-connected driving mass blocks displace in the opposite direction.

[0031] Explanation of reference numerals: 1. First detection area; 2. Second detection area; 3. Third detection area; 4. Fourth detection area; 5. Rhombic series drive coupling beam mechanism; 6. Lever parallel drive coupling beam; 7. Comb capacitor group; 8. Drive beam; 9. Drive mass block; 10. H-shaped detection beam; 11. Coriolis mass block; 12. Detection coupling beam; 13. Drive positive comb teeth; 14. Drive detection comb teeth positive electrode; 15. Drive detection comb teeth negative electrode; 16. Drive negative comb teeth; 17. Cantilever beam; 18. Rhombic deformation frame; 19. Cap wafer; 20. Device wafer; 21. Device cavity layer; 22. Etching layer; 23. Anchor point; 24. Cap wafer cavity layer; 25. Detection electrode plate; 26. Orthogonal compensation electrode plate. Detailed implementation manners

[0032] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further introduced in detail below in conjunction with the accompanying drawings.

[0033] Embodiment 1 As Figures 1-3 shown, a gyroscope detection structure, which is divided into four detection areas that are symmetric with each other up, down, left, and right by mutually perpendicular x and y symmetry axes, and are defined as the first detection area 1, the second detection area 2, the third detection area 3, and the fourth detection area 4; The first detection area 1 is connected to the second detection area 2, and the third detection area 3 is connected to the fourth detection area 4 respectively through corresponding rhombic series drive coupling beam mechanisms 5; Furthermore, the rhombic series drive coupling beam mechanism 5 is composed of a group of mutually parallel cantilever beams 17 and a rhombic deformation frame 18 located between the cantilever beams 17; Furthermore, the upper and lower vertices of the rhombic deformation frame 18 are connected to the corresponding drive mass blocks 9.

[0034] The first detection area 1 is connected to the third detection area 3, and the second detection area 2 is connected to the fourth detection area 4 respectively through corresponding lever parallel drive coupling beams 6; Each of the detection areas includes: At least two comb capacitor groups 7, which are connected to an electrical signal; Furthermore, the comb capacitor group 7 is composed of drive positive comb teeth 13, drive detection comb teeth positive electrode 14, drive detection comb teeth negative electrode 15, and drive negative comb teeth 16 arranged from top to bottom along the y-axis direction.

[0035] At least four drive beams 8, and each drive beam 8 is installed on the corresponding comb capacitor group 7; At least one drive mass block 9, and both ends of the drive mass block 9 are respectively connected to two drive beams 8; At least two H-shaped detection beams 10; At least one Coriolis mass 11, which is mounted on the gyro detection structure through a corresponding detection coupling beam 12: One end of the H-shaped detection beam 10 is connected to the driving mass block 9, and the other end thereof is connected to the Coriolis mass block 11; After receiving the electrical signal, the comb-tooth capacitor group 7 drives the comb teeth to move periodically, thereby driving the driving mass block 9 on the driving beam 8 to move periodically; The driving mass 9 in the first detection zone 1 and the driving mass 9 in the second detection zone 2 move in opposite directions; the driving mass 9 in the third detection zone 3 and the driving mass 9 in the fourth detection zone 4 move in opposite directions.

[0036] Specifically, the gyro detection structure is based on a precise symmetrical layout and mechanical coupling design. Through mutually perpendicular x- and y-axis of symmetry, the overall space is divided into four detection areas that are completely symmetrical in the upper and lower directions, and are named the first detection area 1, the second detection area 2, the third detection area 3, and the fourth detection area 4. This symmetrical design not only achieves a balance in the mechanical properties of the structure, but also significantly improves the detection accuracy and stability. In terms of the drive coupling mechanism, the first detection area 1 and the second detection area 2, and the third detection area 3 and the fourth detection area 4 are connected by a diamond-shaped serial drive coupling beam mechanism 5. The mechanism consists of a group of parallel cantilever beams 17 and a diamond-shaped deformation frame 18 located between the cantilever beams 17. Among them, the upper and lower vertices of the diamond-shaped deformation frame 18 are precisely connected to the corresponding drive beam 8 to form a unique force conduction path. When the detection area is subjected to force, the diamond-shaped deformation frame 18 will undergo elastic deformation, and with its special geometric structure, the force will be evenly and efficiently transmitted to the connected detection areas, realizing the synchronous coordination of the drive movement. The first detection area 1 and the third detection area 3, and the second detection area 2 and the fourth detection area 4 are connected by lever-connected parallel driving coupling beam 6. The coupling beam uses the lever principle to distribute and transmit the driving force in a specific proportion and direction, further enhancing the collaborative working ability of the entire detection structure. Each detection area is equipped with precise sensing and driving components. At least two comb-tooth capacitor groups 7 are connected to an external electrical signal source to form the core driving and detection unit. The comb-tooth capacitor group 7 is composed of a driving positive comb tooth 13, a driving detection comb tooth positive electrode 14, a driving detection comb tooth negative electrode 15 and a driving negative comb tooth 16 arranged in sequence from top to bottom along the y-axis direction. When an electrical signal is applied to the comb-tooth capacitor group 7, based on the electrostatic drive principle, a periodically changing electric field force is generated between the comb teeth, thereby driving the comb teeth to move periodically. At least four driving beams 8 are fixed on the corresponding driving mass blocks 9 to serve as the force transmission bridges. The driving beams 8 are made of high-strength materials with good elasticity, which can effectively amplify the tiny displacement of the comb teeth and transmit it to the driving mass blocks 9. Both ends of at least one driving mass block 9 are respectively connected to two driving beams 8, and under the drive of the driving beams 8, it moves periodically along the driving direction. In addition, at least two H-shaped detection beams 10 are provided in each detection area to transmit the motion state of the driving mass blocks 9. At least one Coriolis mass block 11 is installed on the gyroscope detection structure through the corresponding detection coupling beam 12, which is the key component for detecting the angular velocity.

[0037] During the working process, the driving mass blocks 9 in the first detection area 1 and the driving mass blocks 9 in the second detection area 2 move in opposite directions. This benefits from the ingenious design of the diamond series driving coupling beam mechanism 5, which utilizes the symmetry and elastic deformation characteristics of the structure to make the driving forces in the two detection areas opposite to each other; similarly, the driving mass blocks 9 in the third detection area 3 and the driving mass blocks 9 in the fourth detection area 4 also move in opposite directions. This reverse motion mode not only improves the sensitivity of the detection structure to external angular velocity changes but also effectively suppresses external interference through mutual compensation, greatly enhancing the accuracy and reliability of gyroscope detection.

[0038] Embodiment 2 As Figure 4 shown, a gyroscope, which is formed by bonding a device wafer 20 and a cap wafer 19; The device wafer 20 includes a device cavity layer 21 and an etched layer 22 having the gyroscope detection structure described in the above Embodiment 1; Furthermore, the cap wafer 19 includes: at least a plurality of anchor points 23, which are used to fix the etched layer 22 on the cap wafer 19 and provide electrical signals to the comb tooth capacitor group 7 through the anchor points 23; A cap wafer cavity layer 24; At least four detection electrode plates 25, which are located on the cap wafer cavity layer 24 directly below the corresponding Coriolis mass blocks 11; As Figure 4 shown, at least four orthogonal compensation electrode plates 26, which are located on the cap wafer cavity layer 24 directly below the corresponding Coriolis mass blocks 11 and are individually controlled; the orthogonal compensation electrode plates 26 are used to add orthogonal compensation electrodes in the detection direction of the gyroscope. By controlling the current of the orthogonal compensation electrode plates, an electrostatic force is generated on the Coriolis mass blocks, so that the Coriolis mass blocks at both ends of the lever coupling beam are maintained in the same state; Furthermore, the Coriolis mass blocks 11 in the first detection area 1 and the Coriolis mass blocks 11 in the fourth detection area 4 move in the same direction and are connected in series with the corresponding detection electrode plates 25; The Coriolis mass 11 in the second detection zone 2 and the Coriolis mass 11 in the third detection zone 3 move in the same direction and are connected in series with the corresponding detection electrode plates 25 .

[0039] Specifically, the gyroscope adopts advanced wafer bonding technology, and is formed by precision bonding of a device wafer 20 and a cap wafer 19. This bonding process not only ensures a stable connection between the two wafers, but also builds a closed and stable working environment, laying the foundation for the high-precision operation of the gyroscope.

[0040] The device wafer 20, as the core functional carrier of the gyroscope, includes a device cavity layer 21 and an etching layer 22. The device cavity layer 21 mainly provides necessary space for the internal structure to ensure that each component can move freely without interfering with each other; the etching layer 22 integrates the gyroscope detection structure described in the above embodiment 1, which undertakes the key task of converting angular velocity signals into detectable physical quantities by virtue of its exquisite symmetrical design and coupling beam mechanism. The cap wafer 19 plays an indispensable role in the entire gyroscope system, and its structure and functional design are also very sophisticated. The cap wafer 19 contains at least a plurality of anchor points 23, which are like precise "connectors". They are not only used to firmly fix the etched layer 22 on the cap wafer 19 to ensure the mechanical stability of the entire structure, but also bear the important responsibility of transmitting electrical signals. The anchor point 23 is connected to the comb-tooth capacitor group 7, and can accurately provide it with electrical signals, so that the comb-tooth capacitor group 7 can work normally, thereby driving the gyroscope detection structure to operate. The cap wafer cavity layer 24 cooperates with the device wafer device cavity layer 21 to form a closed space inside the gyroscope, effectively isolating external environmental interference and ensuring stable operation of internal components. At least four detection electrode plates 25 are located on the cap wafer cavity layer 24 directly below the corresponding Coriolis mass block 11, which can accurately capture the tiny displacement changes of the Coriolis mass block 11 when it is affected by angular velocity, and convert these changes into electrical signal outputs, providing key data for subsequent angular velocity calculations.

[0041] At least four orthogonal compensation electrode plates 26 are also located on the cap wafer cavity layer 24 directly below the corresponding Coriolis mass block 11, and each orthogonal compensation electrode plate 26 has the ability to be independently controlled. During the detection process of the gyroscope, due to factors such as machining errors and external interference, orthogonal errors may occur, affecting the detection accuracy. The orthogonal compensation electrode plate 26 is born to solve this problem. By accurately controlling the orthogonal compensation plate current, it can generate a specific electrostatic force on the Coriolis mass block, cleverly adjust the state of the Coriolis mass blocks at both ends of the lever coupling beam, so that it always maintains the same working state, effectively eliminates the orthogonal error, and significantly improves the detection accuracy of the gyroscope. During the working process, there is a precise cooperation relationship among the detection areas of the gyroscope. The Coriolis mass blocks 11 in the first detection area 1 and the Coriolis mass blocks 11 in the fourth detection area 4 move in the same direction. The detection electrode plates 25 connected to them are combined in series, and such a design can integrate the signals of the two detection areas, enhance the signal intensity, and improve the reliability of detection; similarly, the Coriolis mass blocks 11 in the second detection area 2 and the Coriolis mass blocks 11 in the third detection area 3 move in the same direction, and the corresponding detection electrode plates 25 connected to them are also in series to achieve effective superposition and processing of signals. Through this ingenious layout and connection method, the entire gyroscope system can efficiently and accurately complete the angular velocity detection task.

[0042] Embodiment 3 As Figures 5-6 shown, a method for a gyroscope to detect angular velocity, which is applied to the gyroscope described in the above Embodiment 2, and the method includes: S1. When the gyroscope is in the working state, drive the drive positive comb teeth 13 and the drive negative comb teeth 16 on both sides of the drive mass block 9 to drive the drive mass block 9 to perform periodic motion along the y-axis.

[0043] S2. The drive mass block 9 and the corresponding Coriolis mass block 11 are rigidly connected, and the Coriolis mass block 11 performs periodic motion along the drive direction; S3. When the series-connected drive mass blocks 9 move in the reverse direction, the drive mass blocks 9 on both sides drive the rhombic deformation frame 18 to change, causing the cantilever beams 17 on both sides to displace in the x-axis direction, realizing a reduction in the stiffness influence on the gyroscope; S4. Under the combined action of the rhombic series drive coupling beam mechanism 5 and the lever parallel drive coupling beam 6, the adjacent drive mass blocks perform equal and opposite motions, realizing a reduction in the influence of the common-mode noise on the drive displacement output of the drive mass blocks; S5. When the gyroscope rotates along the x-axis direction at a specified angular rate, the Coriolis mass block 11 moves along the z-axis direction under the action of the Coriolis force; S6. The Coriolis mass block 11 and the corresponding detection electrode plate 25 form a capacitance change amount, and by detecting the capacitance change amount, the torsion angle of the Coriolis mass block 11 is obtained.

[0044] S7. According to the gyroscope detection displacement formula, the torsion angle of the Coriolis mass block 11 is positively correlated with the input angular velocity of the gyroscope. Detect the capacitance change amounts between the four Coriolis mass blocks 11 and the detection electrode plates 25 to obtain the angular velocity input to the gyroscope.

[0045] Among them, the gyroscope detection displacement formula, that is, the gyroscope detection capacitance sensitivity formula: ; Among them,

[0046] In the formula, is the initial capacitance of the detection electrode, is the distance from the center of the detection electrode structure to the rotating shaft, is the initial gap between the plates of the detection electrode, is the torsional angle of the Coriolis mass block, is the size of the Coriolis mass block, is the magnitude of the driving force, is the quality factor in the driving direction, is the input angular velocity of the gyroscope, is the distance between the centroid coordinate of the detection mass block and the torsion center, the size of the driving mass block, is the moment of inertia of the detection mass block, is the driving angular frequency, is the detection angular frequency, is the quality factor in the detection direction.

[0047] Furthermore, as Figure 7 shown, the method further includes: when the initial position of the Coriolis mass block 11 is not zero, controlling the orthogonal compensation plate current through the orthogonal compensation electrode to generate an electrostatic force on the Coriolis mass block 11, so that the Coriolis mass blocks 11 at both ends of the lever coupling beam are maintained in the same state, and the influence of reducing the orthogonal error on the device is completed.

[0048] In the prior art, as Figure 5 shown, due to the completely symmetric structure adopted in the design of the four-mass gyro, the stiffness and damping received by the driving co-directional displacement and the driving counter-directional displacement in the adjacent driving mass blocks are the same, and the co-directional mode will be introduced as an interference mode. When the two modes are mixed together, the gyro test accuracy is reduced.

[0049] As Figure 8 shown, when the series-connected driving mass blocks 9 perform co-directional displacement, the series-connected driving mass blocks 9 will receive a relatively large stiffness along the y direction of the cantilever beam. As Figure 9 shown, when the series-connected driving mass blocks 9 perform reverse movement, the driving mass blocks 9 on both sides drive the diamond-shaped deformation frame 18 to change, causing the cantilever beams 17 on both sides to displace in the x-axis direction and being affected by a relatively small stiffness. The co-directional mode and the reverse mode of the series-connected driving mass blocks are distinguished by the diamond-shaped series driving coupling beam mechanism 5, and the interference between modes is suppressed. Similarly, as Figure 10 and Figure 11As shown, when the driving mass blocks 9 in parallel move in the same direction, they are affected by a relatively large stiffness; when moving in the opposite direction, the stiffness is smaller and it is easier to be driven. Under the combined action of the diamond-shaped series drive coupling beam mechanism 5 and the lever parallel drive coupling beam 6, the adjacent driving mass blocks 9 move in equal and opposite directions, reducing the influence of common-mode noise on the driving displacement output of the driving mass blocks 9.

[0050] By adopting an opposed-door swing detection structure, the lever parallel drive coupling beam 6 and the H-shaped detection beam 10 are respectively located on both sides of the Coriolis mass block 11, effectively increasing the detection area of the Coriolis mass block 11.

[0051] At the same time, since the driving mode displaces along the driving direction, while the detection mode twists along the detection sensitive axis direction, the two do not interfere with each other, achieving mechanical decoupling between the driving structure and the detection structure.

[0052] Only some exemplary embodiments of the present invention have been described above by way of illustration. Without doubt, for those of ordinary skill in the art, the described embodiments can be modified in various different ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. Gyroscope detection structure, characterized in that, The gyroscope detection structure is divided into four symmetric detection regions, namely the upper, lower, left, and right regions, by the mutually perpendicular x and y symmetry axes, and is defined as the first detection region (1), the second detection region (2), the third detection region (3), and the fourth detection region (4). The first detection region (1) is connected to the second detection region (2), and the third detection region (3) is connected to the fourth detection region (4) through corresponding diamond-shaped series drive coupling beam mechanisms (5). The first detection region (1) is connected to the third detection region (3), and the second detection region (2) is connected to the fourth detection region (4) through corresponding lever parallel drive coupling beams (6). Each detection region includes: At least two comb-shaped capacitor groups (7), which are connected to electrical signals; At least four drive beams (8), each drive beam (8) being mounted on a corresponding comb-shaped capacitor group (7); At least one drive mass block (9), the two ends of the drive mass block (9) being respectively connected to two drive beams (8); At least two H-shaped detection beams (10); At least one Coriolis mass block (11), which is mounted on the gyroscope detection structure through a corresponding detection coupling beam (12): Wherein, one end of the H-shaped detection beam (10) is connected to the drive mass block (9), and the other end is connected to the Coriolis mass block (11); After receiving an electrical signal, the comb-shaped capacitor group (7) drives the periodic movement of the comb teeth, and further drives the periodic movement of the drive mass block (9) on the drive beam (8); The drive mass blocks (9) in the first detection region (1) and the second detection region (2) move in opposite directions; the drive mass blocks (9) in the third detection region (3) and the fourth detection region (4) move in opposite directions.

2. The gyroscope detection structure according to claim 1, wherein The comb-shaped capacitor group (7) is composed of drive positive comb teeth (13), drive detection comb tooth positives (14), drive detection comb tooth negatives (15), and drive negative comb teeth (16) arranged vertically along the y-axis.

3. The gyroscope detection structure according to claim 1, characterized in that The diamond-shaped series drive coupling beam mechanism (5) consists of a group of mutually parallel cantilever beams (17) and a diamond-shaped deformation frame (18) located between the cantilever beams (17).

4. The gyroscope detection structure according to claim 3, wherein, The upper and lower vertices of the diamond-shaped deformation frame (18) are connected to the corresponding drive mass blocks (9).

5. Gyroscope, characterized in that, This gyroscope is formed by bonding a device wafer (20) and a cap wafer (19); The device wafer (20) includes a device cavity layer (21) and an etched layer (22) having the gyroscope detection structure described in any one of claims 1-4.

6. The gyroscope according to claim 5, characterized in that, The cap wafer (19) includes: at least a plurality of anchor points (23), which are used to fix the etched layer (22) on the cap wafer (19) and supply electrical signals to the comb-shaped capacitor group (7) through the anchor points (23); A cap wafer cavity layer (24); At least four detection electrode plates (25), which are located on the cap wafer cavity layer (24) directly below the corresponding Coriolis mass blocks (11); At least four orthogonal compensation electrode plates (26) are located on the cap wafer cavity layer (24) directly below the corresponding Coriolis mass blocks (11), and each orthogonal compensation electrode plate (26) is controlled individually; the orthogonal compensation electrode plates (26) are used to add orthogonal compensation electrodes in the detection direction of the gyroscope, and by controlling the current of the orthogonal compensation electrode plates, an electrostatic force is generated on the Coriolis mass blocks, so that the Coriolis mass blocks at both ends of the lever coupling beam are maintained in the same state.

7. The gyroscope according to claim 6, wherein The Coriolis mass blocks (11) in the first detection area (1) and the Coriolis mass blocks (11) in the fourth detection area (4) move in the same direction and are connected in series with the corresponding detection electrode plates (25); The Coriolis mass blocks (11) in the second detection area (2) and the Coriolis mass blocks (11) in the third detection area (3) move in the same direction and are connected in series with the corresponding detection electrode plates (25).

8. A method for a gyroscope to detect angular velocity, characterized in that This method is applied to the gyroscope described in any one of claims 5-7, and this method includes: S1. When the gyroscope is in the working state, drive the drive positive comb teeth (13) and the drive negative comb teeth (16) on both sides of the drive mass block (9) to drive the drive mass block (9) to perform periodic motion along the y-axis; S2. There is a rigid connection between the drive mass block (9) and the corresponding Coriolis mass block (11), and the Coriolis mass block (11) performs periodic motion along the drive direction; S3. When the series-connected drive mass blocks (9) move in the reverse direction, the drive mass blocks (9) on both sides drive the diamond-shaped deformation frame (18) to change, so that the two cantilever beams (17) are displaced in the x-axis direction, realizing the reduction of the influence on the stiffness of the gyroscope; S4. Under the combined action of the diamond-shaped series drive coupling beam mechanism (5) and the lever parallel drive coupling beam (6), the adjacent drive mass blocks perform equal and opposite motions, realizing the reduction of the influence of the common-mode noise on the drive displacement output of the drive mass blocks; S5. When the gyroscope rotates along the x-axis direction at a specified angular rate, the Coriolis mass block (11) moves along the z-axis direction under the action of the Coriolis force; S6. A capacitance change amount is formed between the Coriolis mass block (11) and the corresponding detection electrode plate (25), and by detecting the capacitance change amount, the torsional angle of the Coriolis mass block (11) is obtained; S7. According to the gyroscope detection displacement formula, the torsional angle of the Coriolis mass block (11) is positively correlated with the input angular velocity of the gyroscope. Detect the capacitance change amounts between the four Coriolis mass blocks (11) and the detection electrode plates (25) to obtain the angular velocity input to the gyroscope.

9. The method for a gyroscope to detect angular velocity according to claim 8, wherein This method also includes: when the initial position of the Coriolis mass block (11) is not zero, control the current of the orthogonal compensation electrode plates through the orthogonal compensation electrodes to generate an electrostatic force on the Coriolis mass block (11), so that the Coriolis mass blocks (11) at both ends of the lever coupling beam are maintained in the same state, and complete the reduction of the influence of the orthogonal error on the device.

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