Multi-dimensional acceleration sensor

Abstract

A multi-dimensional acceleration sensor comprises: a housing which defines an accommodating cavity, is connected with an object to be measured, and moves synchronously with the object to be measured; the supporting part is contained in the containing cavity, and the supporting part is at least provided with a first face and a second face which are perpendicular to each other; the sensing part group comprises a first sensing part attached to the first surface and a second sensing part attached to the second surface; the plurality of optical fibers are in one-to-one correspondence with the sensing parts in the sensing part group, the optical fibers are used for transmitting test optical signals to the corresponding sensing parts and receiving feedback optical signals, and the feedback optical signals are at least used for representing the acceleration of the to-be-tested object in a first plane; the first plane, the first face and the second face are perpendicular to one another. By adopting the acceleration sensor provided by the embodiment of the invention, the acceleration of the to-be-measured object can be obtained more comprehensively and accurately.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and in particular to a multi-dimensional acceleration sensor. Background Art

[0002] At present, the main technical methods commonly used for acceleration sensors are divided into electrical and optical types. Acceleration sensors of the electrical type include piezoelectric technology, piezoresistive technology, and capacitive technology, etc., which are active sensing technologies; acceleration sensors of the optical type include (Fiber Bragg Grating) fiber Bragg grating technology, laser dynamic ranging technology, optical flow field technology, etc., which are passive sensing technologies.

[0003] However, existing electrical acceleration sensors often have common defects. Since they are active detection, in very harsh environments, such as high electromagnetic, high current, high voltage, electrostatic dust, flammable and explosive, extreme temperature (such as less than -50℃ and higher than 120℃), their signals show poor signal-to-noise ratio and cannot even perform effective detection.

[0004] In addition, although the existing optical acceleration sensors are passive sensor chips and can be used in extremely harsh environments, the accuracy of the existing optical acceleration sensors in detecting parameters such as acceleration is often poor. Summary of the invention

[0005] The technical problem solved by the invention is to provide a multi-dimensional acceleration sensor with higher accuracy.

[0006] To solve the above technical problems, an embodiment of the present invention provides a multi-dimensional acceleration sensor, comprising: a shell, defining a accommodating cavity, the shell being connected to an object to be measured and moving synchronously with the object to be measured; a support portion, accommodated in the accommodating cavity, the support portion having at least a first surface and a second surface perpendicular to each other; a sensing portion group, comprising a first sensing portion attached to the first surface and a second sensing portion attached to the second surface; a plurality of optical fibers, corresponding one-to-one to the sensing portions in the sensing portion group, the optical fibers being used to transmit test light signals to the corresponding sensing portions and receive feedback light signals, the feedback light signals being used to at least characterize the acceleration of the object to be measured in a first plane, the first plane, the first surface and the second surface being perpendicular to each other.

[0007] Optionally, the multiple optical fibers include: a first optical fiber, used to transmit a first test light signal to the first sensing unit and receive a first feedback light signal, the first feedback light signal is at least used to characterize the acceleration of the object to be tested in a first direction, the first direction being perpendicular to the first surface; a second optical fiber, used to transmit a second test light signal to the second sensing unit and receive a second feedback light signal, the second feedback light signal is at least used to characterize the acceleration of the object to be tested in a second direction, the second direction being perpendicular to the second surface.

[0008] Optionally, the supporting portion includes: a first through hole extending along the first direction and connected to the first surface, the projection of the first through hole along the first direction falling into the area surrounded by the first sensing portion, at least a section of the first optical fiber being accommodated in the first through hole to transmit the first test optical signal to the first sensing portion and receive the first feedback optical signal; a second through hole extending along the second direction and connected to the second surface, the projection of the second through hole along the second direction falling into the area surrounded by the second sensing portion, at least a section of the second optical fiber being accommodated in the second through hole to transmit the second test optical signal to the second sensing portion and receive the second feedback optical signal.

[0009] Optionally, the multi-dimensional acceleration sensor also includes: a first optical collimator, at least partially extending into the first through hole and coupled to one end of the first optical fiber toward the first sensing portion, and the first optical collimator extends along the first direction; a second optical collimator, at least partially extending into the second through hole and coupled to one end of the second optical fiber toward the second sensing portion, and the second optical collimator extends along the second direction.

[0010] Optionally, the supporting portion further has a third surface, the first surface, the second surface and the third surface are perpendicular to each other, and the sensing portion group further includes: a third sensing portion, attached to the third surface; the multiple optical fibers further include: a third optical fiber, used to transmit a third test light signal to the third sensing portion and receive a third feedback light signal, the third feedback light signal is at least used to characterize the acceleration of the object to be tested in a third direction, and the third direction is perpendicular to the third surface.

[0011] Optionally, the feedback light signal generated by the first sensing unit, the feedback light signal generated by the second sensing unit, and the third feedback light signal are used to jointly characterize the acceleration of the object to be measured in a first space, and the first space is jointly composed of the first plane and the third direction.

[0012] Optionally, for each sensing part in the sensing part group, the sensing part includes: an optical cavity layer, having a first surface and a second surface relative to each other, the test light signal enters from the first surface, and the second surface has a first reflective film; a resonance layer, having a third surface and a fourth surface relative to each other, the third surface faces the second surface, wherein the resonance layer includes: a mass block, the mass block can vibrate in a direction perpendicular to the third surface, and the surface of the mass block facing the second surface has a second reflective film, so that a first optical resonant cavity is formed between the third surface and the surface of the mass block facing the second surface; the feedback light signal passing through the first optical resonant cavity carries the acceleration information of the object to be measured.

[0013] Optionally, the first surface has a first anti-reflection film; the transmittance of the first anti-reflection film is greater than or equal to a first transmittance threshold.

[0014] Optionally, the resonance layer includes: a frame; a plurality of elastic connecting components, which are symmetrically connected to the two inner sides of the frame; the mass block is suspended from the frame through the elastic connecting components and is surrounded by the frame; wherein, the mass block can vibrate in a direction perpendicular to the third surface under the drive of the elastic connecting components.

[0015] Optionally, the plurality of elastic connecting components include at least two groups of elastic connecting components that are distributed in a mirror image; wherein the mirror image planes of the two groups of elastic connecting components are parallel to the plane where the frame is located.

[0016] Optionally, the elastic connecting component is curved or in the shape of a fold line, and includes one or more of the following: the elastic connecting component is an I-shaped fold line; the elastic connecting component is a T-shaped fold line; the elastic connecting component is an S-shaped fold line; the elastic connecting component is a W-shaped fold line; the elastic connecting component is an L-shaped fold line; the elastic connecting component is an X-shaped fold line; the elastic connecting component is an M-shaped fold line; the elastic connecting component is a second structural block with a hollow structure.

[0017] Optionally, the frame, the plurality of elastic connecting components and the mass block are an integrally formed structure formed by a semiconductor manufacturing process.

[0018] Optionally, the fourth surface has a second anti-reflection film; wherein the transmittance of the second anti-reflection film is greater than or equal to a second transmittance threshold.

[0019] Optionally, the second surface has a first recessed portion, and the bottom surface of the first recessed portion is a plane; wherein the first reflective film is located on the bottom surface of the recessed portion; and the projection of the mass block on the second surface is within the bottom surface of the first recessed portion.

[0020] Optionally, the multi-dimensional acceleration sensor also includes: a capping layer having a fifth surface and a sixth surface relative to each other, the fifth surface facing the fourth surface; wherein the surface roughness of the fifth surface is greater than or equal to a first roughness threshold; or, the fifth surface and the sixth surface are both coated with a third anti-reflection film, wherein the transmittance of the third anti-reflection film is greater than or equal to a third transmittance threshold.

[0021] Optionally, the fifth surface has a second recessed portion, and the bottom surface of the second recessed portion is a plane; wherein the surface roughness of the bottom surface of the second recessed portion is greater than or equal to the first roughness threshold; and the projection of the mass block on the fifth surface is within the bottom surface of the second recessed portion.

[0022] Optionally, the multidimensional acceleration sensor includes one or more of the following: the optical cavity layer and the resonance layer are connected by bonding; the distance between the second surface and the third surface is greater than or equal to the maximum displacement of the mass block; the resonance layer and the capping layer are connected by bonding; the optical cavity layer is formed based on a semiconductor substrate after double-sided polishing; the resonance layer is formed based on a semiconductor substrate after double-sided polishing; the capping layer is formed based on a semiconductor substrate after single-sided polishing, and the fifth surface is a polished surface.

[0023] Optionally, the shell also includes: a connecting member, which has a first end and a second end relative to each other along the extension direction, the first end is located in the accommodating cavity and is optically connected to an end of each sensing part in the sensing part group away from the multiple optical fibers, and the second end is suitable for pluggable connection with an optoelectronic device.

[0024] Optionally, the shell includes a first wall and a second wall opposite to each other, the support portion is connected to the first wall, the second wall is provided with an opening connected to the accommodating cavity, and the second end of the connecting member extends out of the accommodating cavity from the opening.

[0025] Optionally, the first wall is provided with a mounting portion, the supporting portion includes a matching portion, and the mounting portion and the matching portion cooperate to position the supporting portion on the first wall.

[0026] Optionally, the multi-dimensional acceleration sensor also includes: a cover portion, which is detachably covered on the second wall and closes the opening; a connecting flange, which has a third end and a fourth end opposite to each other along the extension direction, the third end being accommodated in the accommodating cavity, the fourth end extending from the accommodating cavity to cooperate with the cover portion, and the connecting flange is also provided with a fourth through hole connected to the accommodating cavity, and the second end of the connecting member is exposed outside the accommodating cavity from the fourth through hole.

[0027] Optionally, the shell is connected to the object to be measured through a connecting bracket so that the multi-dimensional acceleration sensor moves synchronously with the object to be measured, and the connecting bracket includes: a first connecting part for connecting to the shell; a second connecting part for connecting to the object to be measured; and a reinforcing rib for strengthening the connection strength between the first connecting part and the second connecting part.

[0028] Compared with the prior art, the technical solution of the embodiment of the present invention has the following beneficial effects: By adopting the technical solution of the present application, by attaching a sensing part group on the mutually perpendicular first and second surfaces of the support part, and combining multiple optical fibers to transmit test optical signals and receive feedback optical signals, the multi-dimensional acceleration sensor can simultaneously measure the acceleration of the object to be measured in multiple directions, thereby improving the accuracy and comprehensiveness of the measurement. The multiple optical fibers correspond one-to-one to the multiple sensing parts in the sensing part group, and through precise alignment and coupling, it is ensured that the test optical signal can be accurately transmitted to the corresponding sensing part and receive the corresponding feedback optical signal, thereby improving the accuracy and reliability of the measurement.

[0029] Furthermore, the supporting part also includes a third surface, and the first surface, the second surface and the third surface are perpendicular to each other and are respectively provided with corresponding sensing parts. By obtaining the acceleration components of the object to be measured in three directions perpendicular to each other in the three-dimensional space, the acceleration of the object to be measured in the three-dimensional space can be accurately obtained.

[0030] Furthermore, the design of the connector enables the optical fiber to be pluggably connected to the optoelectronic device, thereby improving the flexibility and scalability of the multi-dimensional acceleration sensor and facilitating the testing and maintenance of the multi-dimensional acceleration sensor.

[0031] Furthermore, each sensing part has an optical cavity layer and a resonance layer, and the resonance layer includes a mass block that can vibrate in a direction perpendicular to the third surface of the resonance layer. A first optical resonance cavity can be formed between the second surface of the optical cavity layer and the surface of the mass block, so that laser signals (such as test optical signals and feedback optical signals) can be used to measure parameters of the mass block (such as inertial force or displacement), which helps to improve the ability to resist electromagnetic interference and has application advantages in extreme environments, thereby effectively improving the precision of detecting acceleration. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a schematic diagram of a multi-dimensional acceleration sensor according to an embodiment of the present invention; Figure 2 yes Figure 1 An exploded view of the structure shown; Figure 3 yes Figure 2 Schematic diagram of the middle part structure in assembled state; Figure 4 yes Figure 3 A schematic diagram of the structure shown from another perspective; Figure 5 yes Figure 2 A schematic diagram of the central body; Figure 6 yes Figure 1 A schematic diagram of the cooperation between the multi-dimensional acceleration sensor and the connecting bracket is shown; Figure 7 yes Figure 2 Schematic diagram of the cross-sectional structure of the middle sensing part; Figure 8 yes Figure 7 An exploded view of the structure shown; Fig. 9 It is a schematic diagram of the reflection spectrum of the dual FP interferometer temperature-acceleration integrated sensor chip; Fig.10 It is a schematic diagram of the number of frequency peaks / valleys in the periodic spectrum of the reflected light of the double FP interferometer cavity after DFT; Fig.11 Interference cavity Schematic diagram of the reflected photoperiodic spectrum; Fig.12 Interference cavity Schematic diagram of the reflected photoperiodic spectrum. DETAILED DESCRIPTION

[0033] As mentioned in the background art, existing electrical acceleration sensors often have common defects, and existing optical acceleration sensors often have poor accuracy in detecting parameters such as acceleration.

[0034] Specifically, to measure the quality of an accelerometer, it is often necessary to comprehensively consider multiple working parameters, such as one or more of the following: frequency response bandwidth, high g value (acceleration measurement amplitude), shock resistance, resolution, linearity, long-term stability, sensitivity temperature stability, zero drift temperature stability and operating temperature range.

[0035] After research, it was found that for the existing electrical acceleration sensors, piezoelectric technology has very good parameters in frequency response bandwidth, high g value, shock resistance, and linearity, but it is very weak in other parameters; piezoresistive technology is similar to piezoelectric technology, but lacks in frequency response bandwidth; on the contrary, capacitance technology is very good in resolution, linearity, long-term stability, sensitivity temperature stability, and zero drift temperature stability, and other parameters are mediocre. However, electrical measurement technologies have some common defects. Since they belong to active detection, in very harsh environments, such as high electromagnetic, high current, high voltage, electrostatic dust, flammable and explosive, extreme temperature (such as less than -50℃ and higher than 120℃), the signal performance is poor signal-to-noise ratio, and even cannot perform effective detection work.

[0036] For existing optical acceleration sensors, although fiber Bragg grating technology is a passive sensing technology with strong anti-electromagnetic interference capabilities and can also be used in environments such as electrostatic dust, flammable and explosive materials, and extreme temperatures, as a sensitive element of the acceleration sensor, it cannot be compared with electrical sensing methods in terms of the above-mentioned parameters.

[0037] In addition, laser dynamic ranging technology and optical flow field technology are subject to interference from ambient light pollution, and are therefore only suitable for measuring short distances and light-free indoor environments or air-permeable outdoor environments, and are not suitable for acceleration detection that requires high precision.

[0038] In order to solve the above technical problems, an embodiment of the present invention provides a multidimensional acceleration sensor, including: a shell, defining a accommodating cavity, the shell being connected to an object to be measured and moving synchronously with the object to be measured; a support portion, accommodated in the accommodating cavity, the support portion having at least a first surface and a second surface perpendicular to each other; a sensing portion group, including a first sensing portion attached to the first surface and a second sensing portion attached to the second surface; a plurality of optical fibers, corresponding one-to-one to the sensing portions in the sensing portion group, the optical fibers being used to transmit test light signals to the corresponding sensing portions and receive feedback light signals, the feedback light signals being used at least to characterize the acceleration of the object to be measured in a first plane, the first plane, the first surface, and the second surface being perpendicular to each other.

[0039] In the embodiment of the present invention, by attaching a sensing part group on the first and second surfaces of the supporting part that are perpendicular to each other, and combining multiple optical fibers to transmit test optical signals and receive feedback optical signals, the multi-dimensional acceleration sensor can simultaneously measure the acceleration of the object to be measured in multiple directions, thereby improving the accuracy and comprehensiveness of the measurement. The multiple optical fibers correspond one-to-one to the multiple sensing parts in the sensing part group, and through precise alignment and coupling, it is ensured that the test optical signal can be accurately transmitted to the corresponding sensing part and receive the corresponding feedback optical signal, thereby improving the accuracy and reliability of the measurement.

[0040] In order to make the above-mentioned objects, features and beneficial effects of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0041] Figure 1 is a schematic diagram of a multi-dimensional acceleration sensor 100 according to an embodiment of the present invention; Figure 2 yes Figure 1 Exploded view of the structure shown.

[0042] Combination Figure 1 and Figure 2 The multi-dimensional acceleration sensor 100 comprises: a shell 1, defining a housing cavity 11, the shell 1 being connected to an object to be measured and moving synchronously with the object to be measured; a support portion 2, accommodated in the housing cavity 11, the support portion 2 having at least a first surface 21 and a second surface 22 perpendicular to each other; a sensing portion group 3, comprising a first sensing portion 31 attached to the first surface 21 and a second sensing portion 32 attached to the second surface 22; a plurality of optical fibers 4, corresponding one to one with the sensing portions 30 in the sensing portion group 3, the optical fibers 4 being used to transmit a test optical signal to the corresponding sensing portion 30 and receive a feedback optical signal, the feedback optical signal being used to at least characterize the acceleration of the object to be measured in a first plane, the first plane, the first surface 21 and the second surface 22 being perpendicular to each other.

[0043] Specifically, the housing 1 is used to constitute the external protection structure of the multi-dimensional acceleration sensor 100, and defines a housing cavity 11. The housing cavity 11 is used to accommodate internal components such as the support portion 2, the sensing portion group 3, and the optical fiber 4. Further, the housing 1 is connected to the object to be measured and can move synchronously with the object to be measured, thereby ensuring that the sensor can accurately measure the acceleration of the object to be measured.

[0044] In some embodiments, the housing 1 can be made of a material with high strength, corrosion resistance, wear resistance, etc., such as stainless steel, aluminum alloy, zinc alloy, copper alloy, etc. Thus, it can be ensured that the housing 1 can protect the internal components (such as the support part 2, the sensing part group 3, and the optical fiber 4), and extend the service life of the multi-dimensional acceleration sensor 100.

[0045] In some embodiments, the housing 1 may be in the shape of a cuboid, for example. Thus, the cuboid housing 1 has a simple structure and is easy to process and install.

[0046] In some embodiments, the shape of the housing 1 may also be a streamlined shape such as a cylinder or a sphere. Thus, when the multi-dimensional acceleration sensor 100 moves synchronously with the object to be measured, the interference and influence of environmental factors such as wind resistance on the measurement result can be reduced.

[0047] Furthermore, the support part 2 is accommodated in the accommodating cavity 11 and is a carrier of the sensing part group 3. The support part 2 has at least a first surface 21 and a second surface 22 which are perpendicular to each other and are used to attach the sensing part 30 in the sensing part group 3 for sensing the acceleration of the object to be measured in different directions.

[0048] In some embodiments, the support portion 2 may be, for example, a polyhedral structure, and include at least two mutually perpendicular surfaces for forming the first surface 21 and the second surface 22 .

[0049] Further, the sensing part group 3 may include a plurality of sensing parts 30, and the plurality of sensing parts 30 are respectively attached to the first surface 21 and the second surface 22 of the support part 2. For example, the plurality of sensing parts 30 include a first sensing part 31 and a second sensing part 32, the first sensing part 31 is attached to the first surface 21 to sense the acceleration of the object to be measured in the first direction D1, and the second sensing part 32 is attached to the second surface 22 to sense the acceleration of the object to be measured in the second direction D2. Thus, the multi-dimensional acceleration sensor 100 can at least obtain the acceleration of the object to be measured in the first direction D1 and the second direction D2.

[0050] In some embodiments, the multi-dimensional acceleration sensor 100 can be coupled to an optoelectronic device, which can synthesize the acceleration of the object to be measured in the first plane according to the acceleration in the first direction D1 and the second direction D2 through the principle of vector synthesis. The first plane is defined by the first direction D1 and the second direction D2.

[0051] In some embodiments, multiple sensors 30 may be provided on each plane of the support portion 2, for example, two or more sensors 30 may be attached to the first surface 21 and the second surface 22, respectively. Thus, multiple acceleration measurement data may be obtained simultaneously, so that the measurement error is further reduced. Even if an individual sensor 30 fails or is abnormal during use, other sensors 30 in the same direction may still obtain accurate measurement data.

[0052] Furthermore, the plurality of optical fibers 4 correspond one-to-one to the sensing parts 30 in the sensing part group 3. The optical fibers 4 are used to transmit a test optical signal to the corresponding sensing part 30 and receive a feedback optical signal fed back by the sensing part 30. The feedback optical signal is used to at least characterize the acceleration of the object to be tested in the first plane.

[0053] From the above, by attaching the sensing part group 3 on the mutually perpendicular first surface 21 and second surface 22 of the support part 2, and combining multiple optical fibers 4 to transmit test optical signals and receive feedback optical signals, the multi-dimensional acceleration sensor 100 can simultaneously measure the acceleration of the object to be measured in multiple directions, thereby improving the accuracy and comprehensiveness of the measurement. The multiple optical fibers 4 correspond one-to-one to the multiple sensing parts 30 in the sensing part group 3, and through precise alignment and coupling, it is ensured that the test optical signal can be accurately transmitted to the corresponding sensing part 30, and the corresponding feedback optical signal can be received, thereby improving the accuracy and reliability of the measurement.

[0054] Combination Figures 2 to 4 In some embodiments, the plurality of optical fibers 4 include: a first optical fiber 41, used to transmit a first test optical signal to the first sensing unit 31 and receive a first feedback optical signal, the first feedback optical signal at least being used to characterize the acceleration of the object to be tested in a first direction D1, the first direction D1 being perpendicular to the first surface 21; a second optical fiber 42, used to transmit a second test optical signal to the second sensing unit 32 and receive a second feedback optical signal, the second feedback optical signal at least being used to characterize the acceleration of the object to be tested in a second direction D2, the second direction D2 being perpendicular to the second surface 22. Thus, the first optical fiber 41 and the second optical fiber 42 can independently and accurately cooperate with the corresponding sensing unit 30 (for example, the first sensing unit 31 and the second sensing unit 32) to obtain acceleration information in the corresponding direction, and can effectively avoid mutual interference between test optical signals emitted in different directions or feedback optical signals fed back.

[0055] Specifically, the first optical fiber 41 corresponds to the first sensing unit 31 and can send a test optical signal to the first sensing unit 31. Further, when the object to be tested generates acceleration in the first direction D1, the first sensing unit 31 will respond and reflect the first feedback optical signal. In this scenario, the acceleration of the object to be tested in the first direction D1 can be obtained by demodulation and analysis based on the difference between the first feedback optical signal fed back from the first sensing unit 31 and the initial first test optical signal received by the first optical fiber 41.

[0056] Similarly, the second optical fiber 42 corresponds to the second sensing unit 32 and can send a test optical signal to the second sensing unit 32. Further, when the object to be tested generates acceleration in the second direction D2, the second sensing unit 32 will respond and reflect the second feedback optical signal. In this scenario, the acceleration of the object to be tested in the second direction D2 can be obtained by demodulation and analysis based on the difference between the second feedback optical signal fed back from the second sensing unit 32 and the initial second test optical signal received by the second optical fiber 42.

[0057] Further, the support portion 2 includes: a first through hole 201 extending along the first direction D1 and connected to the first surface 21, along the first direction D1, the projection of the first through hole 201 falls into the area surrounded by the first sensing portion 31, at least one section of the first optical fiber 41 is accommodated in the first through hole 201 to transmit the first test optical signal to the first sensing portion 31 and receive the first feedback optical signal; a second through hole 202 extending along the second direction D2 and connected to the second surface 22, along the second direction D2, the projection of the second through hole 202 falls into the area surrounded by the second sensing portion 32, at least one section of the second optical fiber 42 is accommodated in the second through hole 202 to transmit the second test optical signal to the second sensing portion 32 and receive the second feedback optical signal. Therefore, in practical applications, by inserting the optical fiber 4 into the corresponding through hole, it can be ensured that one end of the optical fiber 4 that transmits and receives the optical signal is aligned with the corresponding sensing portion 30. For example, the first optical fiber 41 is inserted into the first through hole 41 , and one end of the first optical fiber 41 that transmits the first test optical signal and receives the first feedback optical signal can be aligned with the first sensing unit 31 , thereby ensuring the accuracy of the acquired acceleration data.

[0058] Specifically, the first through hole 201 extends along the first direction D1, that is, the extending direction of the first through hole 201 is perpendicular to the first sensing portion 31 attached to the first surface 21. Therefore, the first through hole 201 can provide guidance for the first optical fiber 41 inserted therein, ensuring that the first optical fiber 41 is aligned with the first sensing portion 31.

[0059] Furthermore, along the first direction D1, the projection of the first through hole 201 falls into the area surrounded by the first sensing portion 31. Thus, it can be ensured that the first optical fiber 41 can be accurately aligned with the first sensing portion 31 and interact with each other.

[0060] In a preferred embodiment, along the first direction D1, the core of the first optical fiber 41 in the first through hole 201 is aligned with the geometric center of the first sensing portion 31. In other words, the first test optical signal emitted by the first optical fiber 41 is accurately directed to the geometric center of the first sensing portion 31. Thus, the accuracy of acceleration measurement can be ensured.

[0061] Similar to the first through hole 201, the second through hole 202 can ensure that the second test optical signal emitted by the second optical fiber 42 is accurately directed to the geometric center of the second sensing part 32. Thus, the accuracy of acceleration measurement can be ensured. The extension direction of the second through hole 202, the matching method with the second optical fiber 42, etc., can refer to the above description of the first through hole 201, which will not be repeated here.

[0062] In some embodiments, the multi-dimensional acceleration sensor 100 further includes: a first optical collimator 51, at least partially extending into the first through hole 201 and coupled with one end of the first optical fiber 41 toward the first sensing portion 31, and the first optical collimator 51 extends along the first direction D1; a second optical collimator 52, at least partially extending into the second through hole 202 and coupled with one end of the second optical fiber 42 toward the second sensing portion 32, and the second optical collimator 52 extends along the second direction D2. Thus, through the first optical collimator 51 and the second optical collimator 52, the transmission efficiency and measurement accuracy of the optical signal (first test optical signal, first feedback optical signal, second test optical signal, second feedback optical signal) in the multi-dimensional acceleration sensor 100 are effectively improved, which helps to ensure that the optical signal can be transmitted to the corresponding sensing portion 30 along the correct path. As a result, the multi-dimensional acceleration sensor 100 has higher accuracy and reliability when measuring the acceleration of the object to be measured.

[0063] Specifically, the first optical collimator 51 at least partially extends into the first through hole 201 of the support portion 2, and is coupled with one end of the first optical fiber 41 that faces the first sensing portion 31. This coupling ensures that the first test optical signal can be efficiently transmitted from the first optical fiber 41 to the first optical collimator 51, and then to the first sensing portion 31. Correspondingly, the first feedback optical signal can also be transmitted back to the first optical fiber 41 through the first optical collimator 51.

[0064] Similarly, the second optical collimator 52 at least partially extends into the first through hole 201 of the support portion 2, and is coupled with one end of the second optical fiber 42 toward the second sensing portion 32. This coupling ensures that the first test optical signal can be efficiently transmitted from the second optical fiber 42 to the second optical collimator 52, and then transmitted to the second sensing portion 32. Correspondingly, the first feedback optical signal can also be transmitted back to the second optical fiber 42 through the second optical collimator 52.

[0065] In some embodiments, continue to refer to Figures 2 to 4 The support part 2 also has a third surface 23, the first surface 21, the second surface 22 and the third surface 23 are perpendicular to each other, and the sensing part group 3 also includes: a third sensing part 33, attached to the third surface 23. The multiple optical fibers 4 also include: a third optical fiber 43, used to transmit a third test optical signal to the third sensing part 33 and receive a third feedback optical signal, and the third feedback optical signal is at least used to characterize the acceleration of the object to be measured in a third direction D3, and the third direction D3 is perpendicular to the third surface 23. Therefore, by introducing the third surface 23, the third sensing part 33 and the third optical fiber 43, the multi-dimensional acceleration sensor 100 can realize a comprehensive measurement of the acceleration of the object to be measured in three-dimensional space, thereby improving the accuracy and reliability of the measurement.

[0066] Specifically, the third surface 23 of the support portion 2 is perpendicular to the first surface 21 and the second surface 22. Thus, the support portion 2 forms a three-dimensional structure, providing three independent and two-two perpendicular attachment surfaces for the multiple sensing portions 30 in the sensing portion group 3, so that the acceleration of the object to be measured in three different directions can be measured.

[0067] Further, the third sensing unit 33 is similar to the first sensing unit 31 and the second sensing unit 32, and is used to sense the acceleration of the object to be tested in the third direction D3. In practical applications, the third optical fiber 43 is used to transmit a third test optical signal to the third sensing unit 33, and receive a third feedback optical signal from the third sensing unit 33. The change of the optical signal can reflect the acceleration information of the object to be tested in the third direction D3.

[0068] Furthermore, the multi-dimensional acceleration sensor 100 further includes: a third optical collimator 53, at least partially extending into the third through hole 203 and coupled with one end of the third optical fiber 43 toward the third sensing portion 33, and the third optical collimator 53 extends along the third direction D3. Thus, the acceleration of the object to be measured in the third direction D3 can be accurately obtained.

[0069] In some embodiments, the end face of each optical collimator among the first optical collimator 51, the second optical collimator 52 and the third optical collimator 53 may have an AR (Anti-Reflection) film to avoid the formation of an FP interference cavity in the gap between the optical collimator and the corresponding sensing unit 30, thereby avoiding adverse effects on signal demodulation.

[0070] In some embodiments, the types of optical collimators may include focusing lenses, fiber lenses, G-lens (Gradient-index lens) self-focusing gradient lens, C-lens (Conventional-lens) spherical lens, etc. In addition, for the cross section of the cut optical fiber 4, since the cut surface is perpendicular to the axial direction of the fiber core, a certain coupling effect can be achieved within a certain distance (the distance between the end face of the optical fiber cross section and the mass block 3023 is from 0 microns to 300 microns).

[0071] In some embodiments, the feedback light signal (i.e., the first feedback light signal) generated by the first sensing unit 31, the feedback light signal (i.e., the second feedback light signal) generated by the second sensing unit 32, and the third feedback light signal are used to jointly characterize the acceleration of the object to be measured in the first space, and the first space is jointly composed of the first plane and the third direction D3. Among them, the first plane is defined by the first direction D1 and the second direction D2. In other words, the first direction D1, the second direction D2, and the third direction D3 jointly define the first space. Therefore, by integrating the acceleration information of these three directions, the multi-dimensional acceleration sensor 100 can accurately characterize the motion state of the object to be measured in the three-dimensional space.

[0072] In a typical application scenario, the acceleration information in three directions (for example, the first direction D1, the second direction D2, and the third direction D3) can be regarded as a three-dimensional vector, whose components correspond to the acceleration in the first direction D1, the second direction D2, and the third direction D3. By calculating the magnitude and direction of this vector, the acceleration magnitude and direction of the object to be measured in the three-dimensional space can be obtained.

[0073] In some embodiments, the multi-dimensional acceleration sensor 100 may further include a plurality of positioning plates 300, which are respectively attached to the first surface 21, the second surface 22, and the third surface 23, and cover the corresponding first sensing portion 31, the second sensing portion 32, and the third sensing portion 33. Thus, the positioning plates 300 can prevent the first sensing portion 31, the second sensing portion 32, and the third sensing portion 33 from accidentally falling off.

[0074] In some embodiments, the multi-dimensional acceleration sensor 100 also includes a connector 6, which has a first end 61 and a second end 62 relative to each other along the extension direction, wherein the first end 61 is located in the accommodating cavity 11 and is optically connected to one end of the plurality of optical fibers 4 that is away from the corresponding sensing portion 30, and the second end 62 is suitable for pluggable connection with an optoelectronic device.

[0075] Specifically, refer to Figures 2 to 4 The connector 6 may further include a coupling member 601 and a plug connector 602 of plug-in connection, wherein the first end 61 is formed on the coupling member 601 , and the second end 62 is formed on the plug connector 602 .

[0076] In some embodiments, the optical fiber 4 is connected to the coupling member 601 to form the end of the first end 61. Further, the coupling member 601 can be a universal optical plug connector, such as MPO (Multi-fiber Push On) connector, FC (Ferrule Contactor, round threaded) / PC (Ferrule Contactor, close contact) connector, FC / APC (Angled Physical Contact, close contact at an angle) connector, LC (Lucent Connector, Lucent Connector), ST (Stab & Twist, card-type circular interface connector), SC (Square Connector, square connector), etc.

[0077] In a specific embodiment, Figures 2 to 4 As shown, the coupling member 601 uses an MPO connector. Furthermore, the number of cores of the MPO connector can be 8 cores, 12 cores, 16 cores, and 24 cores. In the embodiment of the present application, the coupling member 601 can bring together three optical fibers 4 (for example, the first optical fiber 41, the second optical fiber 42, and the third optical fiber 43), and the optical fibers 4 are arranged in a certain line sequence (for example, if a 12-core MPO is used, the optical fibers 4 are connected to the 1st, 4th, and 10th core holes respectively).

[0078] Furthermore, the connector 602 can be pluggably connected to a connector of the same model as the coupling component 601 of an optoelectronic device, thereby realizing optical coupling between the coupling component 601 and the optoelectronic device, so that the optical fiber 4 and the optical fiber of the corresponding optoelectronic device are optically coaxially aligned, thereby facilitating the reception and transmission of optical signals.

[0079] In some embodiments, the shell 1 includes a first wall 101 and a second wall 102 relative to each other, the support portion 2 is connected to the first wall 101, the second wall 102 has an opening connected to the accommodating cavity 11, and the second end 62 of the connecting member 6 extends out of the accommodating cavity 11 from the opening.

[0080] Specifically, combined Figure 2 and Figure 5 The shell 1 may further include a main body 12 and a shell seat 13, the first wall 101 is formed on the main body 12, the second wall 102 is formed on the shell seat 13, the opening is opened on the shell seat 13, and the main body 12 and the shell seat 13 jointly surround the accommodating cavity 11.

[0081] Furthermore, the second end 52 of the connector 6 can extend from the opening to be pluggably connected to the optoelectronic device. Thus, the connection between the multi-dimensional acceleration sensor 100 and the optoelectronic device is more convenient.

[0082] Further, refer to Figure 5 , the first wall 101 is provided with a mounting portion 103, the support portion 2 includes a matching portion 24, and the mounting portion 103 and the matching portion 24 cooperate to position the support portion 2 on the first wall 101. The mounting portion 103 can be, for example, a protrusion extending from the first wall 101 toward the second wall 102, and the matching portion 24 can be, for example, a receiving hole adapted to the shape of the protrusion. Thus, after the protrusion is inserted into the receiving hole, the support portion 2 can be stably connected to the first wall 101 of the housing 1, and keep a synchronous motion state with the housing 1 and the object to be measured, so as to accurately obtain the acceleration information of the object to be measured.

[0083] In some embodiments, reference Figure 3 and Figure 4 The support portion 2 includes a main body P0 and a first arm P1, a second arm P2 and a third arm P3 extending outward from different ends of the main body P0. The extending directions of the first arm P1, the second arm P2 and the third arm P3 are perpendicular to each other. Further, the first surface 21 is formed on the first arm P1, the second surface 22 is formed on the second arm P2, and the third surface 23 is formed on the third arm P3. Correspondingly, the first through hole 201 is opened on the first arm P1 and passes through the first surface 21 and the opposite surface, the second through hole 202 is opened on the second arm P2 and passes through the second surface 22 and the opposite surface, and the third through hole 203 is opened on the third arm P3 and passes through the third surface 23 and the opposite surface.

[0084] In some embodiments, the extension direction of the first arm P1 may be perpendicular to the first direction D1, the extension direction of the second arm P2 may be perpendicular to the second direction D2, and the extension direction of the third arm P3 may be perpendicular to the third direction D3.

[0085] In some embodiments, the support portion 2 can be roughly T-shaped, with the main body P0 located at the horizontal and vertical intersection of the T-shaped structure, and two of the first arm P1, the second arm P2 and the third arm P3 extending from the main body P0 in opposite directions to form a horizontal section of the T-shaped structure, and the other arm extending from the main body P0 in a direction perpendicular to the extending direction of the first arm P1 (or the second arm P2) to form a vertical section of the T-shaped structure.

[0086] For example, refer to Figure 3 and Figure 4 The extending directions of the first arm P1 and the second arm P2 (for example, the third direction D3 and the opposite direction thereof) are parallel to each other, and the extending direction of the third arm P3 (for example, the opposite direction of the second direction D2) is perpendicular to the extending directions of the first arm P1 and the second arm P2.

[0087] From the above, any two arms among the first arm P1, the second arm P2 and the third arm P3 will not interfere with each other to prevent the optical fiber 4 and the optical collimator (for example, the first optical collimator 51, the second optical collimator 52 or the third optical collimator 53) from being inserted into the corresponding through hole (for example, the first through hole 201, the second through hole 202 or the third through hole 203).

[0088] Furthermore, the connector 6 can be disposed on the body P0, that is, located at the horizontal and vertical intersection area of ​​the T-shaped structure. Thus, the optical fibers extending outward from the connector 6 can be coupled to the corresponding sensing parts 30 at a close distance.

[0089] In some embodiments, continue to refer to Figure 3 and Figure 4 The T-shaped support portion 2 is placed in the accommodating cavity 11 with the horizontal section extending up and down and the vertical section extending horizontally. In other words, the second sensing portion 32 is located between the first sensing portion 31 and the third sensing portion 33 along the second direction D2, and the third sensing portion 33 and the first sensing portion 31 are both located on the left side of the second sensing portion 32 along the third direction D3.

[0090] The first surface 21 may be located on the surface of the first arm P1 facing the first wall 101, and accordingly, the first optical collimator 51 extends from the surface opposite to the first surface 21 in a direction away from the first wall 101. Thus, the surface of the support portion 2 facing the first wall 101 is substantially flat, which is conducive to stably supporting the support portion 2 in the housing 1.

[0091] The second surface 22 can be located on the surface of the second arm P2 that is farther away from the third arm P3 among the two surfaces that are opposite along the second direction D2, and the third surface 23 can be located on the surface of the third arm P3 that is farther away from the second arm P2 among the two surfaces that are opposite along the third direction D2. Accordingly, the second collimator 52 and the third collimator 53 are respectively arranged close to the second arm P2 and the third arm P3. As a result, the entire T-shaped structure has no additional protruding structure, the overall size of the support part 2 is small, the volume of the accommodating cavity 11 is saved, and it is conducive to the miniaturized design of the multi-dimensional acceleration sensor 100. Furthermore, the optical fiber extending from the connector 6 can be extended to the corresponding optical collimator as far as possible with the shortest distance under the premise of as little bending as possible, thereby reducing costs.

[0092] Furthermore, in the T-shaped support portion 2 , the vertical section of the second arm P2 is closer to the first arm P1 than the third arm P3 , so as to reserve enough space for installing the second collimator 52 and the third collimator 53 in the area where the second arm P2 and the third arm P3 face each other.

[0093] In some embodiments, continue to refer to Figure 3 and Figure 4, the thickness of the first arm P1 along the first direction D1, the thickness of the second arm P2 along the second direction D2, and the thickness of the third arm P3 along the third direction D3 are all equal. Thus, it can be ensured that the lengths of the first through hole 201, the second through hole 202, and the third through hole 203 are all equal, and the first optical collimator 51, the second optical collimator 52, and the third optical collimator 53 can use optical collimation sensors of the same model (length), which is conducive to reducing production costs.

[0094] In a practical application scenario, the support portion 2 can be made by a cutting process or an injection molding process, thereby simplifying the manufacturing process.

[0095] In some embodiments, the support part 2 may be fixed to the first wall 101 by means of fixing members such as bolts, so as to prevent the support part 2 from accidentally shaking during use, thereby affecting the accuracy of the measurement result.

[0096] For example, Figure 3 and Figure 4 In the illustrated embodiment, the support portion 2 may be dispersedly provided with a plurality of (eg, three) fixing holes extending along the first direction, and the fixing members may pass through the fixing holes and be fixedly connected to the first wall 101 to stably fix the support portion 2 on the first wall 101 .

[0097] In some embodiments, the multi-dimensional acceleration sensor 100 may further include: a cover 7, which is detachably covered on the second wall 102 and closes the opening; a connecting flange 8, which has a third end 81 and a fourth end 82 opposite to each other along the extension direction, wherein the third end 81 is accommodated in the accommodating cavity 11, and the fourth end 82 extends from the accommodating cavity 11 to cooperate with the cover 7. Thus, when not in use, the cover 7 can be used to close the opening to achieve dust and moisture-proof functions, so as to prevent dust, water vapor, etc. in the environment from entering the accommodating cavity 11 and affecting the service life of the internal components.

[0098] In some embodiments, the connecting flange 8 further defines a fourth through hole 83 communicating with the accommodating cavity 11 , and the second end 62 of the connecting member 6 is exposed to the outside of the accommodating cavity 11 through the fourth through hole 83 .

[0099] In some embodiments, the portion of the connector 6 accommodated in the fourth through hole 83 and the inner wall of the connecting flange 8 forming the fourth through hole 83 are detachably connected via a connecting structure. The connecting structure may, for example, include a hook provided on one of the connector 6 and the connecting flange 8, and a slot provided on the other of the connector 6 and the connecting flange 8. Thus, through the coupling and decoupling of the hook and the slot, the connector 6 and the connecting flange 8 can be relatively easily inserted or removed.

[0100] In some embodiments, the housing seat 13 includes a through hollow portion for the connecting flange 8 to pass through. Further, the cross-sectional shape of the hollow portion and the cross-sectional shape of the connecting flange 8 can both be set to be non-circular. Thus, the hollow portion on the housing seat 13 can also limit the connecting flange 8 from rotating accidentally.

[0101] Furthermore, a sealing structure 200 may be provided between the main body 12 and the housing seat 13 of the housing 1 , and between the connecting flange 8 and the housing seat 13 , so as to seal the accommodating cavity 11 .

[0102] In some embodiments, the housing 2 may have a hollow portion for the fourth end 82 of the connecting flange 8 to pass through. Furthermore, at least a portion of the connector 602 is exposed to the outside of the accommodating cavity 11 through the fourth through hole 83 of the connecting flange 8 to facilitate plugging with the optoelectronic device.

[0103] Furthermore, a protruding ring structure 84 is also provided on the connecting flange 8 and is located on a side of the housing seat 13 facing the main body 12 .

[0104] Furthermore, the section of the connecting flange 8 extending out of the accommodating cavity 11 may be sleeved with a snap ring 14 , and the snap ring 14 cooperates with the protruding ring structure 84 to stably connect the connecting flange 8 to the housing seat 13 , thereby increasing the overall structural stability of the multi-dimensional acceleration sensor 100 .

[0105] In some embodiments, the cover 7 can be hung on the connecting flange 8 by a connecting belt 15 to prevent the cover 7 from being lost.

[0106] In some embodiments, reference Figure 6 The housing 1 is connected to the object to be measured through a connecting bracket 9, so that the multi-dimensional acceleration sensor 100 moves synchronously with the object to be measured. The connecting bracket 9 includes: a first connecting portion 91, which is used to connect to the housing 1; a second connecting portion 92, which is used to connect to the object to be measured; and a reinforcing rib 93, which is used to strengthen the connection strength between the first connecting portion 91 and the second connecting portion 92. Therefore, the connecting bracket 9 ensures that the multi-dimensional acceleration sensor 100 can be stably installed on the object to be measured and accurately measure its acceleration through the synergistic effect of the first connecting portion 91, the second connecting portion 92 and the reinforcing rib 93.

[0107] Specifically, the first connection part 91 can be fixedly connected to the housing 1 by a fixing member (such as a screw), and the second connection part 92 can also be fixedly connected to the object to be measured by a fixing member (such as a screw). In this way, it can be ensured that the multi-dimensional acceleration sensor 100 and the object to be measured always maintain the same motion state, avoiding interference and influence of environmental factors on the measurement and acquisition of acceleration.

[0108] Figure 7 yes Figure 2 A schematic cross-sectional structure diagram of a single sensing unit 30, Figure 8 yes Figure 7 Exploded view of the structure shown.

[0109] Next, we will combine Figure 7 and Figure 8 right Figure 2 The specific structure of each sensing unit 30 is described in detail.

[0110] refer to Figure 7 and Figure 8 For each sensing part 30 in the sensing part group 3, the sensing part 30 includes: an optical cavity layer 301, having a first surface 3011 and a second surface 3012 opposite to each other, the test light signal enters from the first surface 3011, and the second surface 3012 has a first reflection film; a resonance layer 302, having a third surface 3021 and a fourth surface 3022 opposite to each other, the third surface 3021 faces the second surface 3012, wherein the resonance layer 302 includes: a mass block 3023, the mass block 3023 can vibrate in a direction perpendicular to the third surface 3021, and the surface of the mass block 3023 facing the second surface 3012 has a second reflection film, so that a first optical resonance cavity is formed between the third surface 3021 and the surface of the mass block 3023 facing the second surface 3012; and the feedback light signal passing through the first optical resonance cavity carries the acceleration information of the object to be measured.

[0111] Thus, each sensing unit 30 can obtain the acceleration in the direction perpendicular to the third surface 3021. Figures 1 to 6 The configuration of the first sensing unit 31, the second sensing unit 32 and the third sensing unit 33 in the embodiment, combined with the principle of vector synthesis and decomposition, enables the multi-dimensional acceleration sensor 100 to obtain the acceleration of the object to be measured in any direction in the first space.

[0112] Specifically, a laser signal (eg, a test light signal) may enter from the first surface 3011 , wherein the second surface 3012 may have a first reflective film.

[0113] The third surface 3021 faces the second surface 3012 , wherein the resonance layer 302 may include: a mass block 3023 .

[0114] The mass block 3023 can vibrate in a direction perpendicular to the third surface 3021 , and a second reflective film may be provided on the surface of the mass block 3023 facing the second surface 3012 , so that a first optical resonant cavity is formed between the third surface 3021 and the surface of the mass block 3023 facing the second surface 3012 .

[0115] It can be understood that when a light wave (such as a laser signal) enters the first optical resonant cavity, the incident light wave and the reflected light wave interfere with each other, and after multiple reciprocating reflections on the cavity mirrors at both ends, the multiple light beams interfere to form a standing wave.

[0116] The cavity length of the first optical resonant cavity is the distance between two reflective mirrors (such as the first reflective film and the second reflective film).

[0117] It should be pointed out in particular that Figure 8 The cavity length of the first optical resonant cavity in is used to represent the absolute cavity length, that is, the cavity length of the first optical resonant cavity when the mass block 3023 is stationary, which can also be called the effective cavity length.

[0118] Further, the resonant layer 302 may include: a frame 3024; a plurality of elastic connecting components 3025, wherein the plurality of elastic connecting components 3025 are symmetrically connected to the two inner sides of the frame 3024; the mass block 3023 is suspended on the frame 3024 through the elastic connecting components 3025 and is surrounded by the frame 3024; wherein the mass block 3023 can vibrate in a direction perpendicular to the third surface 3021 under the drive of the elastic connecting components 3025.

[0119] In a specific implementation, by driving the mass block 3023 with the elastic connecting component 3025 to vibrate in a direction perpendicular to the third surface 3021 , the mass block 3023 can move back and forth in the optical cavity of the sensing unit 30 , thereby realizing the resonance function of the resonance device.

[0120] Furthermore, the plurality of elastic connection components 3025 include at least two groups of elastic connection components 3025 that are distributed in a mirror image; wherein the mirror image planes of the two groups of elastic connection components 3025 are parallel to the plane where the frame 3024 is located.

[0121] Specifically, the elastic connection component 3025 can also be called a resonance beam according to its function. The mass block 3023 and the resonance beam structure of the resonance layer 302 can be obtained by etching on a double-sided polished silicon wafer.

[0122] By making the mirror planes of the two sets of elastic connecting components 3025 parallel to the plane where the frame 3024 is located, it can be achieved that the resonant beam includes two layers, the upper beam pattern structure and the lower beam pattern structure are distributed in mirror symmetry.

[0123] In the embodiment of the present invention, by making the mirror planes of the two groups of elastic connecting parts 3025 parallel to the plane where the frame 3024 is located, a design of an upper and lower double-layer resonant beam can be obtained, which effectively reduces the sensitivity of the lateral displacement (such as the direction parallel to the surface of the mass block 3023) of the mass block 3023 in the acceleration sensor chip, and ensures that the mass block 3023 only performs reciprocating motion (also called piston motion) in the axial direction perpendicular to the surface of the mass block 3023 (that is, the vibration direction of the acceleration sensor chip).

[0124] It should be noted that the elastic connecting component 3025 may not adopt a two-layer structure, but a single-layer structure.

[0125] Furthermore, the elastic connecting component 3025 is curved or folded, and may include one or more of the following: the elastic connecting component 3025 is an I-shaped folded line; the elastic connecting component 3025 is a T-shaped folded line; the elastic connecting component 3025 is an S-shaped folded line; the elastic connecting component 3025 is a W-shaped folded line; the elastic connecting component 3025 is an L-shaped folded line; the elastic connecting component 3025 is an X-shaped folded line; the elastic connecting component 3025 is an M-shaped folded line; the elastic connecting component 3025 is a second structural block with a hollow structure.

[0126] Taking the elastic connection component 3025 as an S-shaped broken line as an example, the projection figure of each group of elastic connection components 3025 in the two groups of elastic connection components 3025 on the parallel surface of the third surface 3021 is "S"-shaped; each group of elastic connection components 3025 includes a plurality of first beams arranged in parallel, a second beam connecting adjacent first beams, and a third beam connecting the first beams and the inertial mass block 3023.

[0127] Taking the elastic connection component 3025 in the form of an I-shaped fold line as an example, the projection shape of each group of elastic connection components 3025 in the two groups of elastic connection components 3025 on the plane parallel to the third surface 3021 is a bar.

[0128] The shapes of various elastic connecting components 3025 including the "I" shape and "S" shape have better buffering effect in the horizontal direction, and have the characteristics of high sensitivity, high linearity, and strong resistance to lateral interference, thereby improving the sensitive structure's resistance to lateral vibration interference and impact damage; in addition, this shape of the elastic connecting component 3025 structure is more suitable for production using semiconductor process technology.

[0129] The high sensitivity means that under the action of a force perpendicular to the surface of the mass block 3023, the mass block 3023 is prone to displacement and deformation in the vertical direction perpendicular to the surface of the mass block 3023; the strong anti-lateral interference ability means that under the action of a force parallel to the surface of the mass block 3023, the mass block 3023 has a large rigidity and is not prone to displacement and deformation.

[0130] In other embodiments, the shape of the elastic connecting member 3025 may be more complex, for example, it may be a combination of multiple types of fold lines. In other words, the embodiment of the present invention is not limited to a single fold line shape.

[0131] In some embodiments, the frame 3024, the plurality of elastic connection components 3025, and the mass block 3023 are an integrally formed structure formed using a semiconductor manufacturing process.

[0132] In a specific embodiment, the fourth surface 3022 may have a second anti-reflection film (see Figure 8 ), wherein the transmittance of the second anti-reflection film may be greater than or equal to a second transmittance threshold.

[0133] In a specific implementation, the second transmittance threshold may be set to 50%, that is, the transmittance of the second anti-reflection film may be greater than or equal to 50%.

[0134] In some embodiments, the second surface 3012 may have a first recessed portion 30121, and the bottom surface of the first recessed portion 30121 is a plane; wherein the first reflective film may be located on the bottom surface of the recessed portion; and the projection of the mass block 3023 on the second surface 3012 is within the bottom surface of the first recessed portion 30121.

[0135] In some embodiments, the optical cavity layer 301 is formed based on a semiconductor substrate after double-side polishing.

[0136] Continue to combine Figure 7 and Figure 8 The sensing unit 30 also includes: a capping layer 303, having a fifth surface 3031 and a sixth surface 3032 relative to each other, the fifth surface 3031 facing the fourth surface 3022; wherein the surface roughness of the fifth surface 3031 is greater than or equal to a first roughness threshold; or, the fifth surface 3031 and the sixth surface 3032 are both coated with a third anti-reflection film, wherein the transmittance of the third anti-reflection film is greater than or equal to a third transmittance threshold.

[0137] In a specific embodiment, the first roughness threshold may be represented by the surface average roughness Ra and / or the surface root mean square roughness Rq.

[0138] For example, the surface roughness of the fifth surface 3031 may include one or more of the following: Ra≥1 nm, Rq≥1 nm.

[0139] Specifically, due to the greater surface roughness of the fifth surface 3031, more diffuse reflection can be achieved, effectively avoiding the generation of mirror reflection and the interference of return light signals, and effectively improving the problem of excessive noise inside the sensing unit 30.

[0140] In some embodiments, the fifth surface 3031 and the sixth surface 3032 are both coated with a third anti-reflection film, wherein the transmittance of the third anti-reflection film is greater than or equal to a third transmittance threshold, and the fifth surface 3031 is opposite to the sixth surface 3032 .

[0141] The third transmittance threshold may be selected from 50% to 95%, for example, 80%.

[0142] In a specific implementation, by coating the fifth surface 3031 and the sixth surface 3032 with a film with a high transmittance, more laser signals can penetrate the capping layer 303 instead of generating mirror reflection and returning light signal interference, thereby effectively improving the problem of excessive noise inside the sensing unit 30.

[0143] In some embodiments, the capping layer 303 is formed based on a semiconductor substrate that has been subjected to a single-side polishing process, and the fifth surface 3031 is a polished surface.

[0144] In some embodiments, the fifth surface 3031 has a second recessed portion 30311, and the bottom surface of the second recessed portion 30311 is a plane; wherein the surface roughness of the bottom surface of the second recessed portion 30311 is greater than or equal to the first roughness threshold; the projection of the mass block 3023 on the fifth surface 3031 is within the bottom surface of the second recessed portion 30311.

[0145] Specifically, a concave plane (ie, the second concave portion 30311) can be etched on the upper surface of the single-sided polished silicon wafer. The surface of the concave plane should be rough and should not produce mirror reflection.

[0146] Wherein, by forming the second recessed portion 30311, the lower half of the optical cavity can be formed.

[0147] In the embodiment of the present invention, a second recessed portion 30311 is formed on the fifth surface 3031, and the bottom surface of the second recessed portion 30311 is a plane. The second recessed portion 30311 can be used to allow the formed optical cavity to have a larger space, thereby satisfying the requirement of a larger displacement of the mass block 3023. Furthermore, the bottom surface of the second recessed portion 30311 is a plane, so that the lower half of the formed optical cavity can have better reflection controllability.

[0148] It should be particularly pointed out that in another implementation of the embodiment of the present invention, a frame 3024 structure can be formed between the capping layer 303 and the resonance layer 302, and then an optical cavity with a larger space is formed by bonding the resonance layer 302 and the frame 3024 structure respectively, and bonding the capping layer 303 and the frame 3024 structure respectively.

[0149] In some embodiments, the distance between the second surface 3012 and the third surface 3021 is greater than or equal to the maximum displacement amplitude of the mass block 3023 .

[0150] Specifically, the depth of the depression should be greater than the maximum displacement that the mass block 3023 can withstand during impact vibration. This maximum displacement is related to the maximum stress under the elastic deformation of the material, the mass of the mass block 3023, and the pattern and structure of the elastic connecting component 3025.

[0151] In the embodiment of the present invention, the optical cavity layer 301, the resonance layer 302 and the capping layer 303 are integrated in sequence by bonding to form a sensing unit 30, also called a sensor chip, for example, a silicon-based micro-optical mechanical temperature-acceleration (MicroOpto-Mechanical Accelerometer, MOMA) integrated sensor chip.

[0152] It should be pointed out that the sensing unit 30 obtained in the embodiment of the present invention is essentially a safe passive sensor chip, which can be used in extremely harsh environments. It has the characteristics of being completely immune to electromagnetics and resistant to extreme high and low temperatures.

[0153] In addition, because it uses semiconductor technology and is based on semiconductor substrates (such as single crystal silicon), the material properties of the chip (such as MOMA integrated sensor chip) are the same as those of electrical micro-electro-mechanical system (MEMS) chips, and the production process can be mass-produced, micro-nano-sized, and has good repeatability. Therefore, as an acceleration sensor, MOMA can be comparable to electrical sensors in the test parameters of the acceleration sensor mentioned above, or even better than them.

[0154] In some embodiments, the multi-dimensional acceleration sensor 100 includes one or more of the following: the optical cavity layer 301 and the resonance layer 302 are connected by bonding; the distance between the second surface 3012 and the third surface 3021 is greater than or equal to the maximum displacement of the mass block 3023; the resonance layer 302 and the capping layer 303 are connected by bonding; the optical cavity layer 301 is formed based on a semiconductor substrate after double-sided polishing; the resonance layer 302 is formed based on a semiconductor substrate after double-sided polishing; the capping layer 303 is formed based on a semiconductor substrate after single-sided polishing, and the fifth surface 3031 is a polished surface.

[0155] From the above, by adopting the technical solution of the present application, by attaching the sensing part group 3 on the mutually perpendicular first surface 21 and second surface 22 of the support part 2, and combining multiple optical fibers 4 to transmit test optical signals and receive feedback optical signals, the multi-dimensional acceleration sensor 100 can simultaneously measure the acceleration of the object to be measured in multiple directions, thereby improving the accuracy and comprehensiveness of the measurement. The multiple optical fibers 4 correspond one-to-one to the multiple sensing parts 30 in the sensing part group 3, and through precise alignment and coupling, it is ensured that the test optical signal can be accurately transmitted to the corresponding sensing part 30, and the corresponding feedback optical signal can be received, thereby improving the accuracy and reliability of the measurement.

[0156] Furthermore, the design of the connector 6 enables the optical fiber 4 to be pluggably connected to the optoelectronic device, thereby improving the flexibility and scalability of the multi-dimensional acceleration sensor 100 and facilitating the testing and maintenance of the multi-dimensional acceleration sensor 100.

[0157] Furthermore, each sensing portion 30 has an optical cavity layer 301 and a resonance layer 302, and the resonance layer 302 includes a mass block 3023 that can vibrate in a direction perpendicular to the third surface 3021 of the resonance layer 302, and a first optical resonance cavity can be formed between the second surface 3012 of the optical cavity layer 301 and the surface of the mass block 3023, so that a laser signal (for example, a test optical signal and a feedback optical signal) can be used to measure parameters (such as inertial force or displacement) of the mass block 3023, which helps to improve the anti-electromagnetic interference capability of the multi-dimensional acceleration sensor 100, and has application advantages in extreme environments, thereby effectively improving the precision of acceleration detection.

[0158] In the embodiment of the present application, the sensing unit 30 of the multi-dimensional acceleration sensor 100 uses Fabry-Perot cavity interferometry to obtain the acceleration of the object to be measured.

[0159] The following will combine Figure 7 The principle of acquiring acceleration by the sensing unit 30 in the embodiment of the present application is explained.

[0160] In a typical application scenario, refer to Figure 7 Two Fabry-Perot cavities (F-PCavity, Fabry-Pérot Cavity, also known as Fabry-Perot cavity) are formed in the sensing part 30, that is, the reflectivity is The first surface 3011 and the reflectivity The silicon-based interferometric cavity formed between the second surface 3012 The cavity length is , used to measure temperature changes; and The second surface 3012 and the reflectivity thereof are The gap between the third surface 3012 constitutes an air or vacuum interference cavity The cavity length is , used to measure changes in acceleration, i.e. vibration.

[0161] Furthermore, when a beam of light has an intensity of The light with a spectral range of 1520nm~1580nm (broadband light or wavelength continuously adjustable laser) is used as the carrier of the test optical signal. The first surface 3011 of the sensor 30 first passes through the silicon-based interferometer cavity. , and then through the air or vacuum interference chamber , the light is respectively in the silicon-based interferometer cavity and air or vacuum interference chamber Multiple round-trip reflections are formed inside, and each optical signal (such as feedback optical signal) with temperature information and acceleration information (vibration information) is transmitted through the reflectivity The first surface 3011 has a reflectivity of The second surface 3021 and the reflectivity are The third surface 3021 reflects the light back along the original path in the opposite direction, and the intensity of the reflected light is As shown in Formula 1. External optoelectronic equipment can capture the optical signal in which the temperature and acceleration information are superimposed on each other, and finally restore the real physical quantities, namely temperature and acceleration, through certain demodulation and decoupling algorithms.

[0162] …… (1) in, , and The reflectivity is The first surface 3011 has a reflectivity of The second surface 3012 has a reflectivity of The intensity of the reflected light from the third surface 3021. and Interference cavity and interferometer cavity The phase of can be expressed as, …… (2) …… (3) In formulas (2) and (3), is the speed of light, is the light frequency, and Interference cavity and The refractive index coefficient within the cavity length.

[0163] Therefore, when the sensing unit 30 moves along the optical axis, the mass block 3023 is displaced with the assistance of the elastic connecting component 3025, thereby causing the interference cavity Cavity length Changes in the interferometer cavity Cavity length Only with temperature changes with the changes of.

[0164] To simplify the model, when the mass block 3023 is in steady-state vibration, the following formula is available: …… (4) in, is the mass of the mass block, For time, is the temperature, For over time Changing acceleration values; For over time Variation of the interferometer cavity The displacement of is the elastic coefficient that varies with temperature, which is the interference cavity Any peak-to-peak distance within the frequency As shown in formula (5), by measuring different temperatures of , we can know the corresponding elastic coefficient .

[0165] …… (5) In addition, there is an interference cavity Any peak-to-peak distance within frequency Formula (6), where is room temperature, Room temperature The cavity length when the lower mass block 3023 is stationary.

[0166] …… (6) Combining formulas (4), (5) and (6), we finally get the acceleration As time The function is as follows, …… (7) In a typical application scenario, for the feedback optical signal fed back by the sensing unit 30 (for example, a dual FP interferometer temperature-acceleration integrated sensor chip), the superimposed acceleration signal and temperature signal can be separated and extracted by the following method.

[0167] Fig. 9 The reflection spectrum within the frequency of the dual FP interferometer temperature-acceleration integrated sensor chip is shown, namely , it can be seen that the temperature information and acceleration information are superimposed on each other. Since the optical frequency spectrum of a single FP interferometer cavity is perfectly periodic, that is, the peak-to-peak distances of any adjacent peaks are equal, therefore, for the reflection spectrum of the double FP interferometer cavity , the reflected light periodic spectrum of each FP interferometer cavity within the frequency can be separated and extracted by discrete Fourier transform (DFT).

[0168] In the right Fig. 9 The (reflected) frequency spectrum is obtained by DFT Fig.10 , Fig.10 It is an illustration of the number of frequency peaks / valleys in the periodic spectrum of the reflected light from the double FP interferometer cavity after DFT. Fig.10 Interference cavity shown The frequency peak number of the reflected light period spectrum is , interference cavity The frequency peak number of the reflected light period spectrum is .

[0169] In addition, through Fig. 9 The signal is bandpass filtered at the low and high periods respectively, where the low and high periods are relative to each other and are defined by Fig.10 The number of frequency peaks given and Therefore, Fig.11 Interference cavity The reflected light periodic spectrum has 4 frequency peaks in the same bandwidth, namely , peak-to-peak distance The number of , that is, 3, can be defined as a low period; similarly, Fig.10 and Fig.12 It can be seen that the interference cavity The reflected light period spectrum includes frequency peaks, peak-to-peak distance The number of , relatively defined as a high cycle.

[0170] Therefore, …… (8) …… (9) in, and Interference cavity The minimum and maximum values ​​of the frequency peaks in the reflected light periodic spectrum; similarly, and Interference cavity The minimum and maximum values ​​of the frequency peaks in the reflected light period spectrum. and Then, substitute it into formula (7) to calculate the real-time acceleration value.

[0171] It should be understood that the term "and / or" herein is merely an association relationship describing associated objects, indicating that three relationships may exist, for example, A and / or B, which may represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " herein indicates that the associated objects before and after are in an "or" relationship. As used herein, unless otherwise expressly stated, the term "or" covers all possible combinations unless it is not feasible. For example, if a component is stated to include A or B, then unless otherwise expressly stated or not feasible, the component may include A, or B, or A and B. As a second example, if a component is stated to include A, B, or C, then unless otherwise expressly stated or not feasible, the component may include A, or B, or C, or A and B, or A and C, or B and C, or A and B and C. The "multiple" appearing in the embodiments of the present application refers to two or more.

[0172] The relational terms appearing in the embodiments of the present application, such as first, second, etc., are only used to distinguish an entity or operation from another entity or operation, and do not require or imply any actual relationship or order between these entities or operations. In addition, the words "include", "have" and "comprise" and other similar forms are intended to be equivalent in meaning, and are open-ended, and one or more items behind any of these words are not meant to be an exhaustive list of such one or more items, or mean to be limited to one or more items listed. In the accompanying drawings and the specification, exemplary embodiments have been disclosed. However, many changes and modifications can be made to these embodiments. Therefore, although specific terms have been adopted, they are only used in a general and descriptive sense, not for the purpose of limitation.

[0173] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A multidimensional acceleration sensor, characterized in that: include: A housing defines a receiving cavity, the housing is connected to an object to be measured and moves synchronously with the object to be measured; A support portion, accommodated in the accommodating cavity, wherein the support portion has at least a first surface and a second surface that are perpendicular to each other; A sensing portion group, comprising a first sensing portion attached to the first surface and a second sensing portion attached to the second surface; A plurality of optical fibers correspond one-to-one to the sensing parts in the sensing part group, and the optical fibers are used to transmit test light signals to the corresponding sensing parts and receive feedback light signals, and the feedback light signals are at least used to characterize the acceleration of the object to be tested in a first plane, and the first plane, the first surface and the second surface are perpendicular to each other.

2. The multi-dimensional acceleration sensor according to claim 1, characterized in that: The plurality of optical fibers include: a first optical fiber, used for transmitting a first test optical signal to the first sensing unit and receiving a first feedback optical signal, wherein the first feedback optical signal is at least used for representing the acceleration of the object to be tested in a first direction, wherein the first direction is perpendicular to the first surface; The second optical fiber is used to transmit a second test optical signal to the second sensing part and receive a second feedback optical signal, wherein the second feedback optical signal is at least used to characterize the acceleration of the object to be tested in a second direction, and the second direction is perpendicular to the second surface.

3. The multi-dimensional acceleration sensor according to claim 2, characterized in that: The support portion comprises: a first through hole extending along the first direction and connected to the first surface, wherein a projection of the first through hole along the first direction falls within an area surrounded by the first sensing portion, and at least one section of the first optical fiber is accommodated in the first through hole to transmit the first test optical signal to the first sensing portion and receive the first feedback optical signal; A second through hole extends along the second direction and connects to the second surface. Along the second direction, the projection of the second through hole falls into the area surrounded by the second sensing part. At least a section of the second optical fiber is accommodated in the second through hole to transmit the second test optical signal to the second sensing part and receive the second feedback optical signal.

4. The multi-dimensional acceleration sensor according to claim 3, characterized in that: Also includes: A first optical collimator, at least partially extending into the first through hole and coupled to an end of the first optical fiber facing the first sensing portion, the first optical collimator extending along the first direction; A second optical collimator at least partially extends into the second through hole and is coupled to an end of the second optical fiber facing the second sensing portion, and the second optical collimator extends along the second direction.

5. The multi-dimensional acceleration sensor according to claim 1, characterized in that: The support portion further has a third surface, the first surface, the second surface and the third surface are perpendicular to each other, and the sensing portion group further includes: The third sensing part, attached to the third surface, the plurality of optical fibers further comprises: The third optical fiber is used to transmit a third test optical signal to the third sensing unit and receive a third feedback optical signal, wherein the third feedback optical signal is at least used to characterize the acceleration of the object to be tested in a third direction, and the third direction is perpendicular to the third surface.

6. The multi-dimensional acceleration sensor according to claim 5, characterized in that: The feedback light signal generated by the first sensing unit, the feedback light signal generated by the second sensing unit, and the third feedback light signal are used to jointly characterize the acceleration of the object to be measured in a first space, and the first space is jointly composed of the first plane and the third direction.

7. The multi-dimensional acceleration sensor according to claim 1, characterized in that: For each sensing unit in the sensing unit group, the sensing unit comprises: The optical cavity layer has a first surface and a second surface opposite to each other, the test light signal enters from the first surface, and the second surface has a first reflective film; A resonance layer having a third surface and a fourth surface opposite to each other, wherein the third surface faces the second surface, wherein the resonance layer comprises: A mass block, wherein the mass block can vibrate in a direction perpendicular to the third surface, and a second reflective film is provided on a surface of the mass block facing the second surface, so that a first optical resonant cavity is formed between the third surface and a surface of the mass block facing the second surface; The feedback light signal passing through the first optical resonant cavity carries the acceleration information of the object to be measured.

8. The multi-dimensional acceleration sensor according to claim 7, characterized in that: The first surface has a first anti-reflection film; The transmittance of the first anti-reflection film is greater than or equal to a first transmittance threshold.

9. The multi-dimensional acceleration sensor according to claim 8, characterized in that: The resonance layer comprises: frame; A plurality of elastic connection components, wherein the plurality of elastic connection components are symmetrically connected to two inner sides of the frame; The mass block is suspended on the frame through the elastic connecting component and is surrounded by the frame; Wherein, the mass block can vibrate in a direction perpendicular to the third surface under the drive of the elastic connecting component.

10. The multi-dimensional acceleration sensor according to claim 9, characterized in that: The plurality of elastic connecting components include at least two groups of elastic connecting components distributed in a mirror image; The mirror planes of the two groups of elastic connecting components are parallel to the plane where the frame is located.

11. The multi-dimensional acceleration sensor according to claim 9, characterized in that: The elastic connecting component is in a curved or folded line shape and includes one or more of the following: The elastic connecting component is an I-shaped fold line; The elastic connecting component is in the form of a T-shaped fold line; The elastic connecting component is an S-shaped fold line; The elastic connecting component is a W-shaped fold line; The elastic connecting component is an L-shaped fold line; The elastic connecting component is an X-shaped fold line; The elastic connecting component is an M-shaped fold line; The elastic connecting component is a second structural block with a hollow structure.

12. The multi-dimensional acceleration sensor according to claim 9, characterized in that: The frame, the plurality of elastic connection components and the mass block are an integrally formed structure formed by a semiconductor manufacturing process.

13. The multi-dimensional acceleration sensor according to claim 8, characterized in that: The fourth surface has a second anti-reflection film; Wherein, the transmittance of the second anti-reflection film is greater than or equal to a second transmittance threshold.

14. The multi-dimensional acceleration sensor according to claim 8, characterized in that: The second surface has a first recessed portion, and the bottom surface of the first recessed portion is a plane; Wherein, the first reflective film is located on the bottom surface of the recessed portion; A projection of the mass block on the second surface is within a bottom surface of the first recessed portion.

15. The multi-dimensional acceleration sensor according to claim 8, characterized in that: The multi-dimensional acceleration sensor also includes: A capping layer having a fifth surface and a sixth surface opposite to each other, wherein the fifth surface faces the fourth surface; Wherein, the surface roughness of the fifth surface is greater than or equal to a first roughness threshold; or, The fifth surface and the sixth surface are both coated with a third anti-reflection film, wherein the transmittance of the third anti-reflection film is greater than or equal to a third transmittance threshold.

16. The multi-dimensional acceleration sensor according to claim 15, characterized in that: The fifth surface has a second recessed portion, and the bottom surface of the second recessed portion is a plane; Wherein, the surface roughness of the bottom surface of the second recessed portion is greater than or equal to the first roughness threshold; The projection of the mass on the fifth surface is within the bottom surface of the second recessed portion.

17. The multi-dimensional acceleration sensor according to claim 15, characterized in that: The multi-dimensional acceleration sensor includes one or more of the following: The optical cavity layer and the resonance layer are connected by bonding; The distance between the second surface and the third surface is greater than or equal to the maximum displacement of the mass block; The resonance layer and the cover layer are connected by bonding; The optical cavity layer is formed based on a semiconductor substrate after double-sided polishing; The resonance layer is formed based on a semiconductor substrate after double-sided polishing; The capping layer is formed based on a semiconductor substrate that has been subjected to a single-side polishing process, and the fifth surface is a polished surface.

18. The multi-dimensional acceleration sensor according to any one of claims 1 to 17, characterized in that: The housing further comprises: A connector having a first end and a second end opposite to each other along the extension direction, wherein the first end is located in the accommodating cavity and is optically connected to an end of each sensing part in the sensing part group away from the multiple optical fibers, and the second end is suitable for pluggable connection with an optoelectronic device.

19. The multi-dimensional acceleration sensor according to claim 18, characterized in that: The shell includes a first wall and a second wall opposite to each other. The support portion is connected to the first wall. The second wall is provided with an opening communicating with the accommodating cavity. The second end of the connecting member extends out of the accommodating cavity from the opening.

20. The multi-dimensional acceleration sensor according to claim 19, characterized in that: The first wall is provided with a mounting portion, and the support portion includes a matching portion, and the mounting portion and the matching portion cooperate to position the support portion on the first wall.

21. The multi-dimensional acceleration sensor according to claim 19, characterized in that: Also includes: A cover portion, detachably covered on the second wall and closing the opening; The coupling portion has a third end and a fourth end relatively to each other along the extension direction, the third end is accommodated in the accommodating cavity, the fourth end extends from the accommodating cavity to cooperate with the cover portion, and the coupling portion is also provided with a fourth through hole connected to the accommodating cavity, and the second end of the connecting member is exposed outside the accommodating cavity from the fourth through hole.

22. The multi-dimensional acceleration sensor according to claim 1, characterized in that: The housing is connected to the object to be measured via a connecting bracket so that the multi-dimensional acceleration sensor and the object to be measured move synchronously, and the connecting bracket includes: A first connecting portion, used to connect to the housing; A second connecting portion, used to connect to the object to be tested; The reinforcing rib is used to strengthen the connection strength between the first connecting part and the second connecting part.

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