A miniaturized micro inertial measurement component structure resistant to high overload

Abstract

This invention belongs to the technical field of micro inertial measurement unit (MMU) structure design, and discloses a miniaturized MMU structure resistant to high overload. It includes: an upper buffer energy-absorbing material, a lower buffer energy-absorbing material, an upper shell, a lower shell, and a core adhesive block; both the upper and lower shells are disc-shaped structures with a through hole in the center to accommodate the core adhesive block; four threaded holes are provided around the perimeter for fixing the upper and lower shells; the upper buffer energy-absorbing material is disposed on the upper surface of the upper shell, and the lower buffer energy-absorbing material is disposed on the lower surface of the lower shell; the upper and lower buffer energy-absorbing materials are used to seal the core adhesive block within the upper and lower shells and for buffering and shock absorption; the core adhesive block includes an adhesive material and a micro inertial measurement unit circuit unit sealed within the adhesive material.

Description

Technical Field

[0001] This invention belongs to the field of micro inertial measurement component structure design technology, and relates to a miniaturized micro inertial measurement component structure resistant to high overload. Background Technology

[0002] The micro inertial measurement unit (IMU) uses silicon micro gyroscopes and silicon micro accelerators to measure the angular velocity and acceleration of the carrier. The IMU is formed by orthogonally mounting a 3-axis gyroscope and a 3-axis accelerator. In high-overload applications, the micro IMU offers an irreplaceable size advantage over conventional IMUs composed of laser gyroscopes, fiber optic gyroscopes, and other sensors due to its small size and light weight.

[0003] Since the core sensing structures of silicon micro-gyroscopes and silicon micro-accelerators are movable parts, they can experience significant displacement under high overload applications, which is one of the main reasons for performance degradation or even failure of micro-inertial measurement components. Furthermore, because the application scenarios are size-sensitive, there is a need to invent a miniaturized micro-inertial measurement component structure resistant to high overloads.

[0004] Existing patent CN 111473090, "An Overload-Resistant Vibration Damping Structure for Reusable Micro Inertial Measurement Units," employs a reusable high-overload-resistant vibration damping structure, including an outer shell, inner shell, buffer gaskets, and support frame assembly. This solution solves the problem of buffering and vibration damping for micro inertial measurement components under high overload environments and allows for recycling and maintenance. However, due to the complexity of the components and the large structural size, miniaturization is insufficient. Patent CN 108692723 A, "A High-Overload-Resistant Micro Inertial Measurement Component Structure," adopts a unique support structure and assembly method. Specifically, the printed circuits of six single-axis sensors are respectively mounted on the six mounting surfaces of a hexahedral platform using screws and interconnected via connectors, reducing the assembly complexity of the sensor circuit boards and the overall component. A potting channel is reserved in the structure to ensure the tightness of the potting. This solution reduces the size to a certain extent compared to traditional inertial measurement component structures, but the connectors and screws occupy printed circuit board area, thus limiting further miniaturization of the micro inertial measurement component. Summary of the Invention

[0005] In order to address the various shortcomings of existing overload-resistant structures of micro inertial measurement components, this invention proposes a miniaturized micro inertial measurement component structure that is resistant to high overload.

[0006] A miniaturized micro-inertial measurement component structure resistant to high overload includes: an upper buffer energy-absorbing material, a lower buffer energy-absorbing material, an upper shell, a lower shell, and a core adhesive block;

[0007] Both the upper and lower shells are disc-shaped structures with a through hole in the center to accommodate the core adhesive block; four threaded holes are provided around the perimeter for fixing the upper and lower shells.

[0008] The upper buffer energy-absorbing material is disposed on the upper surface of the upper shell, and the lower buffer energy-absorbing material is disposed on the lower surface of the lower shell; the upper and lower buffer energy-absorbing materials are used to seal the core rubber block inside the upper and lower shells and to buffer and reduce shock.

[0009] The core adhesive block includes adhesive material and a micro inertial measurement component circuit unit sealed within the adhesive material.

[0010] Furthermore, the upper / lower buffer energy-absorbing materials are fixedly connected to the upper / lower shells by adhesive bonding or vulcanization.

[0011] Furthermore, the core adhesive block also includes: an orthogonal platform;

[0012] The orthogonal platform is a cuboid frame structure, and the micro inertial measurement component circuit unit includes at least three circuit boards, which are disposed on the outer surface or inside the orthogonal platform and are orthogonal to each other.

[0013] Each of at least three mutually orthogonal circuit boards has at least one gyroscope and one accelerometer soldered on it.

[0014] Furthermore, the gyroscope and accelerometer are located on opposite sides of the circuit board, respectively.

[0015] Furthermore, the micro inertial measurement component circuit unit includes: a first rigid circuit board, a second rigid circuit board, a third rigid circuit board, a fourth rigid circuit board, a first flexible circuit board, a second flexible circuit board, and a third flexible circuit board.

[0016] The second rigid circuit board, the third rigid circuit board, and the fourth rigid circuit board are connected in sequence to form a "door" shaped structure;

[0017] The first rigid circuit board is positioned in the middle of the "door" shaped structure and is orthogonal to the other three rigid circuit boards;

[0018] The first rigid circuit board is connected to the second rigid circuit board via the first flexible circuit board; the second rigid circuit board is connected via the second and third flexible circuit boards and the third and fourth rigid circuit boards respectively.

[0019] Furthermore, the orthogonal platform is a cuboid frame structure, and the bottom surface is also provided with an annular boss; the first rigid circuit board is disposed on the annular boss; the second, third and fourth rigid circuit boards are disposed on the three connected outer surfaces of the orthogonal platform.

[0020] Furthermore, a gyroscope and an accelerometer are soldered to the front and back surfaces of the first, second, and third rigid circuit boards, respectively;

[0021] Furthermore, the sensitive directions of the gyroscope and accelerometer are perpendicular to the surface of the circuit board.

[0022] Furthermore, the three flexible circuit boards are assembled in the corresponding rigid circuit boards to form an integrated flexible and rigid circuit board structure.

[0023] Furthermore, the circuit connection lines are led out and connected to a rigid circuit board to form a cross-linked electrical signal by soldering wires.

[0024] The present invention has the following effects:

[0025] This invention proposes a miniaturized, high-overload resistant micro-inertial measurement unit (MIM) structure. By mounting a single-axis gyroscope and a single-axis accelerator on opposite sides of the same rigid circuit board, the number of rigid circuit boards is reduced, thus decreasing the overall size of the MIM. The rigid circuit board is mounted to the mounting surface of an orthogonal frame using adhesive bonding, a method less common than screw mounting, reducing mounting locations and the size of the rigid circuit board. Flexible circuit boards are used for electrical connections between connected rigid circuit boards, reducing the number of soldered wires or connectors and further reducing the size of the rigid circuit board. The orthogonal frame, with its perforated design, achieves good conductivity of the potting fluid, increasing the density of the core adhesive block. The mounting surface of the orthogonal frame fully utilizes the space, further reducing the volume of the core adhesive block. The buffer structure, with its upper and lower buffer materials, provides high-overload protection while replacing the commonly used metal shell, effectively reducing the height of the MIM. Simultaneously, the shell connects to the buffer material, encasing the core adhesive block within the buffer material, achieving overload protection in all directions and effectively improving overload resistance. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the rigid-flexible integrated circuit structure in the embodiment;

[0027] Figure 2 This is a schematic diagram of the orthogonal platform structure in the embodiment;

[0028] Figure 3 This is a schematic diagram of the rigid-flexible integrated circuit combined with the orthogonal test bench in the embodiment;

[0029] Figure 4 This is a schematic diagram of the core adhesive block;

[0030] Figure 5 This is a schematic diagram of the miniaturized, high-overload-resistant micro-inertial measurement component structure in the embodiment.

[0031] Among them, 11-rigid circuit board, 12-rigid circuit board, 13-rigid circuit board, 14-rigid circuit board, 15-flexible circuit board, 16-flexible circuit board, 17-flexible circuit board;

[0032] 2-Orthogonal mounting platform, 21-Orthogonal mounting surface, 22-Orthogonal mounting surface, 23-Orthogonal mounting surface, 24-Orthogonal mounting surface, 211-Bonding area, 212-Bonding area, 213-Bonding area, 214-Bonding area

[0033] 3-Core glue block, 31-Side of core glue block, 32-Side of core glue block, 33-Side of core glue block, 34-Side of core glue block, 35-Top of core glue block, 36-Bottom of core glue block;

[0034] 41-Upper buffer energy-absorbing material, 42-Lower buffer energy-absorbing material, 51-Upper shell, 52-Lower shell, 53-Mounting through hole, 54-Mounting through hole. Detailed Implementation

[0035] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the following description, specific details are set forth for purposes of explanation rather than limitation, in order to help to fully understand the present invention.

[0036] It should be noted that, in order to avoid obscuring the invention with unnecessary details, only structures closely related to the solution according to the invention are shown in the accompanying drawings, while other details that are not closely related to the invention are omitted.

[0037] An embodiment of a miniaturized, high-overload-resistant micro-inertial measurement unit is provided, wherein the sensing directions of both the single-axis gyroscope and the single-axis accelerometer are perpendicular to the device orientation. A hardware-software integrated circuit 1 is fabricated using printed circuit board processing technology, such as... Figure 1 As shown, it includes rigid circuit boards 11, 12, 13, and 14, and flexible circuit boards 15, 16, and 17. Flexible circuit board 15 connects to rigid circuit boards 12 and 13, flexible circuit board 16 connects to rigid circuit boards 12 and 14, and flexible circuit board 17 connects to rigid circuit boards 12 and 11. A single-axis gyroscope is mounted on the front side of rigid circuit board 11 using a soldering process, and a single-axis accelerator is mounted on the back side of rigid circuit board 11 using a soldering process. Rigid circuit boards 12 and 13 are mounted using the same mounting method. Rigid circuit board 14 houses components such as a processor chip.

[0038] The integrated hardware and software circuit 1 is mounted on the orthogonal test stand 2, such as... Figure 2 As shown. Epoxy resin adhesive is used to connect the four corners of the rigid circuit board 11 to the bonding area of ​​the mounting surface 21 of the orthogonal frame 2. Using the same installation method, the rigid circuit boards 12, 13, and 14 are connected to the mounting surfaces 22, 23, and 24 of the orthogonal frame 2, respectively.

[0039] After the orthogonal test bench 2 is connected to the rigid-flexible integrated circuit 1, as follows: Figure 3As shown. Through a potting process, epoxy resin is used to cure the orthogonal frame 2 and the rigid-flexible integrated circuit 1 together with the resin block. Tooling is used to form a hexahedral structure on the outer surface of the core resin block 3. The four sides 31, 32, 33, and 34 are parallel to the orthogonal frame mounting surfaces 22 and 24, respectively, while the top and bottom surfaces 35 and 36 are parallel to the orthogonal frame mounting surface 21. Figure 4 As shown.

[0040] The energy-absorbing buffer material 41 on the upper side of the core rubber block is in close contact with the top 35 and the surrounding sides 31, 32, 33, and 34 of the core rubber block. Similarly, the energy-absorbing buffer material 42 on the lower side of the core rubber block is in close contact with the bottom 36 and the surrounding sides 31, 32, 33, and 34 of the core rubber block. The energy-absorbing buffer material 41 is connected to the upper shell 51 via a vulcanization process. The energy-absorbing buffer material 42 is connected to the lower shell 52 via a vulcanization process. The upper shell 51 and the lower shell 52 are bonded together with epoxy resin adhesive. The upper shell 51 and the lower shell 52 have aligned mounting through holes 53 and 54, as shown below. Figure 5 As shown.

[0041] The micro inertial measurement unit is installed on the base by screws through four mounting holes during use.

[0042] Because the single-axis gyroscope and single-axis accelerator are orthogonally mounted in the sensing direction, they can sense the angular rate and acceleration in the three orthogonal directions of x, y, and z, thus measuring the inertia of the carrier motion. Under overload conditions, taking the x-direction as an example, the single-axis gyroscope and single-axis accelerator are fixed inside the core rubber block 3. When subjected to acceleration, they move together with the core rubber block 3, compressing the buffer materials 41 and 42. According to experimental and simulation test results, the peak acceleration under overload will decrease, thereby enabling the miniaturized high-overload resistant micro-inertial measurement component to operate normally.

Claims

1. A miniaturized micro-inertial measurement component structure resistant to high overload, characterized in that: The structure includes: upper buffer energy-absorbing material, lower buffer energy-absorbing material, upper shell, lower shell, and core adhesive block; Both the upper and lower shells are disc-shaped structures with a through hole in the center to accommodate the core adhesive block; four threaded holes are provided around the perimeter for fixing the upper and lower shells. The upper buffer energy-absorbing material is disposed on the upper surface of the upper shell, and the lower buffer energy-absorbing material is disposed on the lower surface of the lower shell; the upper and lower buffer energy-absorbing materials are used to seal the core rubber block inside the upper and lower shells and to buffer and reduce shock. The core adhesive block includes an orthogonal frame, adhesive material, and a micro inertial measurement component circuit unit sealed within the adhesive material; The orthogonal frame is a cuboid frame structure with an annular protrusion on the bottom surface; The micro inertial measurement unit circuit unit includes: a first rigid circuit board, a second rigid circuit board, a third rigid circuit board, a fourth rigid circuit board, a first flexible circuit board, a second flexible circuit board, and a third flexible circuit board; the second, third, and fourth rigid circuit boards are sequentially connected to form a "door" shaped structure; the first rigid circuit board is located in the middle of the "door" shaped structure and is orthogonal to the other three rigid circuit boards; the first rigid circuit board is connected to the second rigid circuit board through the first flexible circuit board; the second rigid circuit board is connected through the second and third flexible circuit boards and the third and fourth rigid circuit boards respectively; the first rigid circuit board is located on the annular boss; the second, third, and fourth rigid circuit boards are located on the three connected outer surfaces of the orthogonal frame; a gyroscope and an accelerometer are respectively welded to the front and back surfaces of the first, second, and third rigid circuit boards; epoxy resin adhesive is used to connect the four corners of the rigid circuit boards to the mounting surface of the orthogonal frame.

2. The structure according to claim 1, characterized in that: The upper and lower energy-absorbing buffer materials are fixedly connected to the upper / lower shells by adhesive bonding or vulcanization.

3. The structure according to claim 2, characterized in that: The gyroscope and accelerometer are located on opposite sides of the circuit board.

4. The structure according to claim 3, characterized in that: The sensitive direction of the gyroscope and accelerometer is perpendicular to the surface of the circuit board.

5. The structure according to claim 4, characterized in that: Three flexible circuit boards are assembled in a corresponding rigid circuit board to form an integrated flexible and rigid circuit board structure.

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