Tuning fork differential detection micromechanical gyroscope structure

Abstract

This invention pertains to inertial sensor technology and relates to a tuning fork-type differential detection micromechanical gyroscope structure. The invention includes a dual-mass block, driving comb teeth, detection comb teeth, an intermediate coupling beam, connecting rods, and elastic beams. The dual-mass block has a symmetrical structure, comprising an outer driving frame vibrating along the x-axis and an inner detection frame vibrating along the y-axis. These two frames are independent of each other and utilize the Coriolis effect to sense the z-axis angular velocity signal. A sensitive signal is output based on the capacitance signal change of the detection comb teeth, and differential calculations are performed. The intermediate coupling beam consists of two symmetrical U-shaped beams. The connecting rods consist of several single beams. This invention reduces the influence of common-mode acceleration noise, reduces mechanical coupling, effectively separates the pseudo-driving mode of in-phase vibration from the driving mode of the outer driving frame from the driving mode of anti-phase vibration, suppresses in-plane rotational modes, and improves the vibration consistency of the U-shaped beams in the driving direction.

Description

Technical Field

[0001] This invention belongs to the field of inertial sensor technology and relates to a tuning fork-type differential detection micromechanical gyroscope structure. Background Technology

[0002] Microelectromechanical systems (MEMS) emerged in the 1980s alongside the development of silicon micromachining technology, representing a combination of microelectronic planar fabrication and silicon micromachining technologies. MEMS features are on the micrometer scale, integrating sensing, actuation, and control technologies. With the advancement of MEMS technology, MEMS gyroscopes are increasingly being used in inertial navigation. Compared to other inertial navigation devices, MEMS gyroscopes offer advantages such as light weight, small size, low cost, and ease of mass production, making them promising for both military and civilian applications.

[0003] Current tuning fork differential detection micromechanical gyroscopes generally lack decoupling structures or have semi-decoupling structures, resulting in large mechanical orthogonal coupling, which seriously affects the output signal; the coupling beam is located in the middle of the left and right frames, which easily generates in-plane rotational modes; the U-shaped beams in the driving direction are independent of each other, resulting in poor vibration consistency. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to propose a tuning fork-type differential detection micromechanical gyroscope structure to reduce mechanical orthogonal error, eliminate in-plane rotational modes, improve the vibration consistency of the U-shaped beam in the driving direction, and improve device performance.

[0005] To achieve the above objectives, the present invention proposes the following technical solution: a tuning fork-type differential detection micromechanical gyroscope structure, comprising a dual mass block, driving comb teeth, detection comb teeth, a middle coupling beam, a connecting rod, and an elastic beam, characterized in that: the dual mass block is a left-right symmetrical structure, with an outer driving frame vibrating along the x-axis and an inner detection frame vibrating along the y-axis. The outer driving frame and the inner detection frame are independent of each other, utilizing the Coriolis effect to sense the z-axis input angular velocity signal, and outputting a sensitive signal through the change in the capacitance signal of the detection comb teeth. During the detection process, differential calculations are performed on the capacitance signals of the detection comb teeth on both sides; the middle coupling beam consists of two symmetrical U-shaped beams; and the connecting rod consists of several single beams.

[0006] The aforementioned driving comb teeth can be six sets of driving comb teeth; the aforementioned detection comb teeth can be four sets of detection comb teeth.

[0007] Compared with the prior art, the present invention has the following advantages: First, the present invention is a symmetrical dual-mass block structure, and differential calculation is performed on the output detection capacitor signal, which can reduce the influence of common-mode acceleration noise; Second, the present invention adopts a fully decoupled design, with the outer driving frame and the inner detection frame being independent of each other, effectively reducing mechanical coupling; Third, the present invention designs two symmetrical U-shaped beams in the middle coupling beam position, which effectively separates the pseudo-driving mode of the outer driving frame vibrating in phase with the driving mode of the outer driving frame vibrating in opposite phase, and suppresses the in-plane rotation mode; Finally, the present invention designs the connecting rod of the driving U-shaped beam as a structure of several single beams, which improves the vibration consistency of the U-shaped beam in the driving direction. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of a specific embodiment of the tuning fork-type differential detection micromechanical gyroscope of the present invention.

[0009] Figure 2 This is a schematic diagram of the driving comb structure of a specific embodiment of the tuning fork-type differential detection micromechanical gyroscope of the present invention;

[0010] Figure 3 This is a schematic diagram of the detection comb structure of a specific embodiment of the tuning fork-type differential detection micromechanical gyroscope of the present invention. Detailed Implementation

[0011] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0012] See Figure 1 A tuning fork-type differential detection micromechanical gyroscope structure is characterized in that: the gyroscope structure is a left-right symmetrical structure, including driving comb teeth, detection comb teeth, intermediate coupling beam, connecting rod, outer driving frame, inner detection frame, detection direction decoupling beam, driving direction decoupling beam, and dual mass blocks.

[0013] The detection direction decoupling beam is a single U-shaped beam, and the driving direction decoupling beam is a single U-shaped beam.

[0014] The drive comb teeth consist of six sets of drive comb teeth, among which fixed drive comb teeth 2, 4, 7, and 9 serve to balance the driving force.

[0015] The detection comb consists of four sets of detection comb teeth.

[0016] The intermediate coupling beam consists of two U-shaped beams, symmetrically positioned at both ends of the left and right outer drive frames.

[0017] The connecting rod is a number of single beams.

[0018] The driving comb teeth are driven by either open-loop or closed-loop drive, and the detection comb teeth are driven by either open-loop or closed-loop drive.

[0019] Figure 1 The detailed structure of the tuning fork-type differential detection micromechanical gyroscope structure shown is as follows:

[0020] (a) The gyroscope is fixed by 10 anchor points: 1, 5, 6, 10, 48, 49, 50, 51, 52, and 53.

[0021] (b) The gyroscope includes two mass blocks 25 and 26 on the left and right sides, which are connected to the outer drive frame 23 and 24 through U-shaped beams 15, 16, 17, 18, 19, 20, 21 and 22 respectively, and are connected to the inner detection frame 35 and 56 through U-shaped beams 27, 28, 29, 30, 31, 32, 33 and 34.

[0022] (c) The outer drive frames 23 and 24 are connected to anchor points 1, 5, 6 and 10 respectively through U-shaped beams 11, 12, 13 and 14, and the inner detection frames 35 and 56 are connected to anchor points 50 and 51 respectively through U-shaped beams 40, 41, 42, 43, 44, 45, 46 and 47.

[0023] (d) The left and right sides are connected to the outer drive frame 23 and 24 by intermediate coupling beams U-shaped beams 54 and 55;

[0024] (e) U-shaped beams 40, 41, 42, 43, 44, 45, 46, and 47 are connected by connecting rods 36, 37, 38, and 39, respectively;

[0025] (f) U-shaped beams 15, 16, 17, 18, 19, 20, 21, and 22 are decoupling beams in the detection direction, and U-shaped beams 27, 28, 29, 30, 31, 32, 33, and 34 are decoupling beams in the driving direction.

[0026] The fixed drive comb teeth 2, 3, 4, 7, 8, and 9 form drive comb teeth with the movable drive comb teeth on the outer drive frames 23 and 24. The movable detection comb teeth on the inner detection frames 35 and 56 form detection comb teeth with the fixed detection comb teeth connected to the same anchor points 52 and 53.

[0027] The two mass blocks 25 and 26 on the left and right sides are completely symmetrical in structure, and achieve the same frequency, equal amplitude, and opposite phase vibration along the X-axis by driving the comb teeth.

[0028] MEMS gyroscopes utilize the Coriolis effect to detect input angular velocity signals through energy conversion between the driving mode and the detection mode. When the gyroscope is working, the fixed driving comb teeth 2, 3, 4, 7, 8, and 9 form a capacitor with the movable driving comb teeth on the outer driving frames 23 and 24. The outer driving frames 23 and 24 vibrate in the same frequency, with equal amplitude, and in opposite phase along the X-axis. This vibration is driven by the detection direction decoupling beams 15, 16, 17, 18, 19, 20, 21, and 22, causing the mass blocks 25 and 26 to vibrate in the same frequency, with equal amplitude, and in opposite phase. When a Z-axis angular velocity signal is input, the mass blocks 25 and 26, affected by the Coriolis effect, vibrate in the same frequency, with equal amplitude, and in opposite phase along the Y-axis. This vibration is driven by the driving direction decoupling beams 27, 28, 29, 30, 31, 32, 33, and 34, causing the inner detection frames 35 and 56 to vibrate in the same frequency, with equal amplitude, and in opposite phase. This causes a change in the capacitance of the detection comb teeth, and the change is proportional to the input angular velocity. The input angular velocity signal can be obtained by differentially calculating the capacitance of the detection comb teeth.

Claims

1. A tuning fork-type differential detection micromechanical gyroscope, comprising dual mass blocks, driving comb teeth, detection comb teeth, intermediate coupling beam, connecting rod, and elastic beam, characterized in that: The dual-mass block has a symmetrical structure, with an outer driving frame vibrating along the x-axis and an inner detection frame vibrating along the y-axis. The outer driving frame and the inner detection frame are independent of each other. The Coriolis effect is used to sense the z-axis input angular velocity signal, and a sensitive signal is output by detecting changes in the capacitance signal of the detection comb teeth. During the detection process, differential calculations are performed on the capacitance signals of the detection comb teeth on both sides. The intermediate coupling beam consists of two symmetrical U-shaped beams. The connecting rod consists of several single beams. The gyroscope is fixed by 10 anchor points. The two masses of the gyroscope are connected to the outer driving frame via U-shaped beams, and connected to the inner detection frame via U-shaped beams. The inner detection frame is connected; the outer drive frame is connected to the anchor point via U-shaped beams, and the inner detection frame is connected to the anchor point via U-shaped beams; the left and right sides of the gyroscope are connected to the outer drive frame via a middle coupling beam U-shaped beam; the U-shaped beams are connected via connecting rods; the U-shaped beams are divided into detection direction decoupling beams and drive direction decoupling beams; the fixed drive comb teeth and the movable drive comb teeth on the outer drive frame form drive comb teeth, and the movable detection comb teeth on the inner detection frame and the fixed detection comb teeth connected to the same anchor point form detection comb teeth; the left and right mass blocks achieve same frequency, equal amplitude, and opposite phase vibration along the X-axis through the drive comb teeth.

2. The tuning fork-type differential detection micromechanical gyroscope according to claim 1, further characterized in that: The driving comb teeth consist of six groups; the detection comb teeth consist of four groups.

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