A MEMS inertial sensor structure and its attitude measurement method

Abstract

This invention belongs to the field of inertial sensor technology, specifically relating to a MEMS inertial sensor structure and its attitude measurement method. It includes a laser layer, an upper grating structure layer, a nanograting inertial component structure layer, and a detector layer. The upper grating structure layer is disposed below the laser layer, the nanograting inertial component structure layer is disposed below the upper grating structure layer, and the detector layer is disposed below the nanograting inertial component structure layer. The nanograting inertial component of this invention consists of an X, Y, and Z-axis gyroscope and a three-axis accelerometer. Its main working principle is that a beam is perpendicularly incident on the grating gyroscope and accelerometer. Due to the Coriolis force and inertial force, the double-layer grating structure undergoes relative motion, resulting in a change in the intensity of the diffracted light behind the double-layer grating. By detecting the change in light intensity, angular rate and acceleration are measured.

Description

Technical Field

[0001] This invention belongs to the field of inertial sensor technology, specifically relating to a MEMS inertial sensor structure and its attitude measurement method. Background Technology

[0002] Attitude calculation is fundamental to achieving high-precision inertial navigation. MEMS gyroscopes and MEMS accelerometers, as core components in attitude calculation, determine its accuracy, thus significantly impacting the success or failure of navigation missions. Therefore, the enormous military and civilian demands urgently require high-precision MEMS gyroscopes and accelerometers for attitude calculation. Attitude calculation involves determining the carrier's attitude angles and position information based on data from inertial measurement units (gyroscopes, accelerometers, etc.). Conventional capacitive inertial components are bulky, have low accuracy, and are susceptible to pull-down effects and parasitic capacitance, especially pronounced in three-axis integration, limiting further improvements in navigation accuracy. Compared to capacitive detection methods, optical detection methods offer advantages such as strong anti-interference electromagnetic capabilities, high precision, and high sensitivity, and are widely used in MEMS inertial devices. Attitude angle detection based on nanograting inertial measurement units is a method with anti-interference and high precision. Ideally, a MEMS gyroscope can be used to measure the attitude angle of a strapdown three-axis system. However, MEMS gyroscopes have integration errors during the measurement process, making it difficult to achieve high accuracy in the calculated attitude angle. Therefore, a MEMS accelerometer is needed to achieve high-precision measurement of the attitude angle. Summary of the Invention

[0003] To address the technical problem that MEMS gyroscopes have integral errors during measurement, making it difficult to achieve high accuracy in the calculated attitude angles, this invention provides a MEMS inertial sensor structure and its attitude measurement method. It uses a nanograting gyroscope and an accelerometer to detect the angular rate and acceleration of the carrier, and combines a quaternion extended Kalman filter algorithm to calculate the attitude angles, thus completing the fusion of multi-sensor information of the inertial component.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0005] A MEMS inertial sensor structure includes a laser layer, an upper grating structure layer, a nanograting inertial component structure layer, and a detector layer. The upper grating structure layer is disposed below the laser layer, the nanograting inertial component structure layer is disposed below the upper grating structure layer, and the detector layer is disposed below the nanograting inertial component structure layer. Light emitted from the laser layer passes through the upper grating structure layer, is incident on the nanograting inertial component structure layer, and finally converges to the detector layer.

[0006] The laser layer includes a first laser diode, a second laser diode, a third laser diode, a fourth laser diode, a fifth laser diode, and a sixth laser diode. The first laser diode, the second laser diode, and the third laser diode are arranged in parallel, and the fourth laser diode, the fifth laser diode, and the sixth laser diode are arranged in parallel.

[0007] The upper grating structure layer includes a first upper grating, a second upper grating, a third upper grating, a fourth upper grating, a fifth upper grating, and a sixth upper grating. The first, second, third, fourth, fifth, and sixth upper gratings are fixedly connected. The first upper grating is positioned in the optical path direction of the first laser diode, the second upper grating is positioned in the optical path direction of the second laser diode, the third upper grating is positioned in the optical path direction of the third laser diode, the fourth upper grating is positioned in the optical path direction of the fourth laser diode, the fifth upper grating is positioned in the optical path direction of the fifth laser diode, and the sixth upper grating is positioned in the optical path direction of the sixth laser diode.

[0008] The nanograting inertial component structure layer includes a first frame and a second frame, which are arranged side by side.

[0009] The first frame includes three square regions. The four corners of the first square region of the first frame are respectively vertically fixed with a first drive beam, a second drive beam, a third drive beam, and a fourth drive beam. The four corners of the second square region of the first frame are respectively vertically fixed with a fifth drive beam, a sixth drive beam, a seventh drive beam, and an eighth drive beam. The four corners of the third square region of the first frame are respectively vertically fixed with a ninth drive beam, a tenth drive beam, an eleventh drive beam, and a twelfth drive beam.

[0010] The first frame has a first mass block, a second mass block, and a third mass block respectively set in the three square areas. The first mass block has a first detection beam, a second detection beam, a third detection beam, and a fourth detection beam fixed at its four corners. The second mass block has a fifth detection beam, a sixth detection beam, a seventh detection beam, and an eighth detection beam fixed at its four corners. The third mass block has a ninth detection beam, a tenth detection beam, an eleventh detection beam, and a twelfth detection beam fixed at its four corners.

[0011] The second frame includes three square regions. The first square region of the second frame is connected to a fourth mass block via a first, second, third, and fourth folded resonant beam. The second square region of the second frame is connected to a fifth mass block via a fifth, sixth, seventh, and eighth folded resonant beam. The four corners of the third square region of the second frame are connected to a sixth mass block via a ninth, tenth, eleventh, and twelfth folded resonant beam.

[0012] A first grating is provided on the first mass block, a second grating is provided on the second mass block, a third grating is provided on the third mass block, a fourth grating is provided on the fourth mass block, a fifth grating is provided on the fifth mass block, and a sixth grating is provided on the sixth mass block.

[0013] The detector layer includes a first laser detector, a second laser detector, a third laser detector, a fourth laser detector, a fifth laser detector, and a sixth laser detector. The first laser detector is arranged in the optical path direction of the first grating, the second laser detector is arranged in the optical path direction of the second grating, the third laser detector is arranged in the optical path direction of the third grating, the fourth laser detector is arranged in the optical path direction of the fourth grating, the fifth laser detector is arranged in the optical path direction of the fifth grating, and the sixth laser detector is arranged in the optical path direction of the sixth grating.

[0014] An attitude measurement method for a MEMS inertial sensor structure includes the following steps:

[0015] S1. Based on the data output by the gyroscope, the three attitude angles of the carrier are directly measured, and the relationship between the measured values ​​and the Euler angles satisfies:

[0016]

[0017] The ω x ω y ω z These represent the angular velocity samples of the gyroscope along three axes within a specified period, namely γ, θ, and θ. These represent the roll angle, pitch angle, and yaw angle, respectively.

[0018] Then the angular rate is converted into the attitude angle magnitude represented by a quaternion;

[0019] S2. When the accelerometer is stationary, its Z-axis is only affected by its own gravity, while the acceleration components of the other two axes are zero. During the motion of the carrier, the Z-axis component changes. Let the accelerations of the carrier along the three axes during motion be a...x a y a z Combining the attitude matrix, we get:

[0020]

[0021] S3. The attitude rotation matrix is ​​the product of the transformation matrices of the carrier during its spatial rotation. The motion state of the carrier is solved by establishing the attitude transformation matrix. The orientation of the carrier in space follows the Z-axis. n Rotating in the order of X1-Y2, and then expressing the transformation matrix between any two coordinates using Euler angles and simplifying it, we get:

[0022]

[0023] Euler angles are represented as follows:

[0024]

[0025] θ=sin -1 (-T 31 )

[0026]

[0027] The γ, θ, These represent the roll angle, pitch angle, and yaw angle output by the accelerometer, respectively.

[0028] S4. Combining the extended Kalman filter algorithm, the model equations are as follows:

[0029]

[0030]

[0031]

[0032]

[0033] In each sampling period, angular velocity and acceleration are variables. The sampled values ​​and the initial values ​​of the quaternions are substituted into the above formula to continuously update the quaternions. The quaternions are converted into Euler angles to represent the attitude angles. The quaternions q0, q1, q2, and q3 are processed through a matrix to convert the quaternion variables into a cosine matrix so that the attitude angles can be solved.

[0034] S5. Attitude calculation equations based on the output data from gyroscope and accelerometer measurements.

[0035]

[0036] From this direction cosine matrix, we obtain the attitude angle equations represented by the four variables in the quaternion:

[0037]

[0038] θ = arcsin(-2(q0q2+q1q3))

[0039]

[0040] The γ, θ, These represent the roll angle, pitch angle, and yaw angle output by the accelerometer, respectively.

[0041] Compared with the prior art, the beneficial effects of this invention are:

[0042] The nano-grating inertial component of this invention consists of an X, Y, and Z-axis gyroscope and a three-axis accelerometer structure. Its main working principle is that a beam of light is incident perpendicularly on the grating gyroscope and accelerometer. Due to the Coriolis force and inertial force, the double-layer grating structure undergoes relative motion, causing a change in the intensity of the diffracted light behind the double-layer grating. By detecting this change in light intensity, angular rate and acceleration are measured. Real-time angular rate and acceleration information provides data for the quaternion algorithm to calculate the attitude angle. The quaternion algorithm effectively solves the singularity problem in the calculation process. An extended Kalman filter algorithm is used to reduce the accumulation of gyroscope integral drift. A complementary filtering algorithm is used to dynamically compensate for high and low frequency errors during inertial sensor operation and to fuse data, further reducing gyroscope integral drift accumulation and suppressing accelerometer vibration errors, thus achieving attitude calculation through multi-sensor data fusion. Attached Figure Description

[0043] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0044] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0045] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0046] Figure 2 This is a diagram showing the integrated arrangement of laser diodes in this invention.

[0047] Figure 3 This is a diagram of the upper grating structure of the present invention;

[0048] Figure 4 This is a schematic diagram of the layer structure of the nanograting inertial component of the present invention;

[0049] Figure 5 This is another structural schematic diagram of the nanograting inertial component structure layer of the present invention;

[0050] Figure 6 This is a diagram showing the arrangement of the detectors in this invention.

[0051] Wherein: 1 is the laser layer, 2 is the upper grating structure layer, 3 is the nano-grating inertial component structure layer, 4 is the detector layer, 5 is the first laser diode, 6 is the second laser diode, 7 is the third laser diode, 8 is the fourth laser diode, 9 is the fifth laser diode, 10 is the sixth laser diode, 11 is the first upper grating, 12 is the second upper grating, 13 is the third upper grating, 14 is the fourth upper grating, 15 is the fifth upper grating, 16 is the sixth upper grating, 17 is the first frame, 18 is... First drive beam, 19 is the second drive beam, 20 is the third drive beam, 21 is the fourth drive beam, 22 is the fifth drive beam, 23 is the sixth drive beam, 24 is the seventh drive beam, 25 is the eighth drive beam, 26 is the ninth drive beam, 27 is the tenth drive beam, 28 is the eleventh drive beam, 29 is the twelfth drive beam, 30 is the first detection beam, 31 is the second detection beam, 32 is the third detection beam, 33 is the fourth detection beam, 34 is the fifth detection beam, 35 is the sixth detection beam, 36 is the seventh detection beam, 37 is the eighth detection beam, 3 8 is the ninth detection beam, 39 is the tenth detection beam, 40 is the eleventh detection beam, 41 is the twelfth detection beam, 42 is the first mass block, 43 is the second mass block, 44 is the third mass block, 45 is the first grating, 46 is the second grating, 47 is the third grating, 48 is the second frame, 49 is the first folded resonant beam, 50 is the second folded resonant beam, 51 is the third folded resonant beam, 52 is the fourth folded resonant beam, 53 is the fifth folded resonant beam, 54 is the sixth folded resonant beam, and 55 is the seventh folded resonant beam. 56 is the eighth folded resonant beam, 57 is the ninth folded resonant beam, 58 is the tenth folded resonant beam, 59 is the eleventh folded resonant beam, 60 is the twelfth folded resonant beam, 61 is the fourth mass block, 62 is the fifth mass block, 63 is the sixth mass block, 64 is the fourth grating, 65 is the fifth grating, 66 is the sixth grating, 67 is the first laser detector, 68 is the second laser detector, 69 is the third laser detector, 70 is the fourth laser detector, 71 is the fifth laser detector, and 72 is the sixth laser detector. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. These descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the claims of the present invention. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0053] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0054] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0055] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0056] In this embodiment, as Figure 1 As shown, the light emitted from the laser layer 1 passes through the upper grating structure layer 2 and is incident on the nanograting inertial component structure layer 3, and finally the laser is focused onto the detector layer 4.

[0057] Furthermore, such as Figure 2 As shown, the first laser diode 5, the second laser diode 6, and the third laser diode 7 are arranged in parallel, and the fourth laser diode 8, the fifth laser diode 9, and the sixth laser diode 10 are arranged in parallel.

[0058] Furthermore, such as Figure 3As shown, the first upper grating 11, the second upper grating 12, the third upper grating 13, the fourth upper grating 14, the fifth upper grating 15, and the sixth upper grating 16 are fixedly connected. The first upper grating 11 is set in the optical path direction of the first laser diode 5, the second upper grating 12 is set in the optical path direction of the second laser diode 6, the third upper grating 13 is set in the optical path direction of the third laser diode 7, the fourth upper grating 14 is set in the optical path direction of the fourth laser diode 8, the fifth upper grating 15 is set in the optical path direction of the fifth laser diode 9, and the sixth upper grating 16 is set in the optical path direction of the sixth laser diode 10.

[0059] Furthermore, such as Figure 4 As shown, the first drive beam 18, the second drive beam 19, the third drive beam 20 and the fourth drive beam 21 are vertically fixed at the four corners of the first square area of ​​the first frame 17, the fifth drive beam 22, the sixth drive beam 23, the seventh drive beam 24 and the eighth drive beam 25 are vertically fixed at the four corners of the second square area of ​​the first frame 17, and the ninth drive beam 26, the tenth drive beam 27, the eleventh drive beam 28 and the twelfth drive beam 29 are vertically fixed at the four corners of the third square area of ​​the first frame 17. The first frame 17 has three square areas where a first mass block 42, a second mass block 43, and a third mass block 44 are respectively set. The first mass block 42 has a first detection beam 30, a second detection beam 31, a third detection beam 32, and a fourth detection beam 33 fixed at its four corners. The second mass block 43 has a fifth detection beam 34, a sixth detection beam 35, a seventh detection beam 36, and an eighth detection beam 37 fixed at its four corners. The third mass block 44 has a ninth detection beam 38, a tenth detection beam 39, an eleventh detection beam 40, and a twelfth detection beam 41 fixed at its four corners.

[0060] Furthermore, such as Figure 5 As shown, the first square region of the second frame 48 is connected to the fourth mass block 61 through the first folded resonant beam 49, the second folded resonant beam 50, the third folded resonant beam 51 and the fourth folded resonant beam 52. The second square region of the second frame 48 is connected to the fifth mass block 62 through the fifth folded resonant beam 53, the sixth folded resonant beam 54, the seventh folded resonant beam 55 and the eighth folded resonant beam 56. The four corners of the third square region of the second frame 48 are connected to the sixth mass block 63 through the ninth folded resonant beam 57, the tenth folded resonant beam 58, the eleventh folded resonant beam 59 and the twelfth folded resonant beam 60.

[0061] Furthermore, a first grating 45 is provided on the first mass block 42, a second grating 46 is provided on the second mass block 43, a third grating 47 is provided on the third mass block 44, a fourth grating 64 is provided on the fourth mass block 61, a fifth grating 65 is provided on the fifth mass block 62, and a sixth grating 66 is provided on the sixth mass block 63.

[0062] Furthermore, such as Figure 6 As shown, a first laser detector 67 is arranged in the optical path direction of the first grating 45, a second laser detector 68 is arranged in the optical path direction of the second grating 46, a third laser detector 69 is arranged in the optical path direction of the third grating 47, a fourth laser detector 70 is arranged in the optical path direction of the fourth grating 64, a fifth laser detector 71 is arranged in the optical path direction of the fifth grating 65, and a sixth laser detector 72 is arranged in the optical path direction of the sixth grating 66.

[0063] In this embodiment, the attitude measurement method for a MEMS inertial sensor structure includes the following steps:

[0064] Gyroscope attitude detection model

[0065] A gyroscope is a device that can detect changes in the angular rate of a carrier. Based on the data output by the gyroscope, the carrier's three attitude angles are directly measured, and the relationship between the measured values ​​and Euler angles satisfies:

[0066]

[0067] ω x ω y ω z This represents the angular velocity sampling of the gyroscope along three axes within a specified period. γ, θ, They represent the roll angle, pitch angle and yaw angle respectively. Equation (1) is the attitude detection model between the angular rate of the gyroscope in the three directions and the Euler angle. According to the calculation method of quaternions, the angular rate can be converted into the attitude angle represented by quaternions.

[0068] Accelerometer Attitude Measurement Model

[0069] When the accelerometer is stationary, its Z-axis acceleration is only affected by its own gravity, while the acceleration components of the other two axes are zero. During the movement of the vehicle, the Z-axis component changes, and acceleration can also be detected along the other two axes (the same applies to the X and Y axes). Let the accelerations of the vehicle along the three axes during motion be a... x a y a z Combining the attitude matrix, we can obtain:

[0070]

[0071] The attitude rotation matrix is ​​the product of the transformation matrices of the carrier during its spatial rotation. The motion state of the carrier can be solved by establishing the attitude transformation matrix. The orientation of the carrier in space follows the Z-axis. n The rotation follows the order X1-Y2. The transformation matrix between any two coordinate systems can be represented using Euler angles and then simplified.

[0072]

[0073] Euler angles (attitude angles) can be expressed as:

[0074]

[0075] θ=sin -1 (-T 31 )#(5)

[0076]

[0077] γ, θ, Let represent the roll angle, pitch angle, and yaw angle output by the accelerometer, respectively. Equations (6), (7), and (8) represent the attitude detection model between the acceleration in the three directions of the accelerometer and the Euler angles. Combining the extended Kalman filter algorithm, the model equations are as follows:

[0078]

[0079]

[0080]

[0081]

[0082] In each sampling period, angular velocity and acceleration are variables. By substituting the sampled values ​​and the initial values ​​of the quaternions into the above equation, the quaternions can be continuously updated. The quaternions are then converted into Euler angles to represent the attitude angles. The quaternions q0, q1, q2, and q3 need to be processed through a matrix to convert the quaternion variables into a cosine matrix before the attitude angles can be calculated. Equation (13) is the attitude calculation equation that combines the output data of the gyroscope and accelerometer measurements.

[0083]

[0084] From this direction cosine matrix, we can obtain the attitude angle equations represented by the four variables in the quaternion:

[0085]

[0086] θ=arcsin(-2(q0q2+q1q3))#(13)

[0087]

[0088] The above description only illustrates the preferred embodiments of the present invention. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention, and all such changes should be included within the protection scope of the present invention.

Claims

1. A MEMS inertial measurement unit sensor structure, characterized by: The application relates to a laser device, which comprises a laser layer (1), an upper grating structure layer (2), a nano grating inertia component structure layer (3) and a detector layer (4), wherein the laser layer (1) is provided below the upper grating structure layer (2), the upper grating structure layer (2) is provided below the nano grating inertia component structure layer (3), and the nano grating inertia component structure layer (3) is provided below the detector layer (4); the light emitted by the laser layer (1) transmits through the upper grating structure layer (2), is incident to the nano grating inertia component structure layer (3), and finally converges to the detector layer (4); the laser layer (1) comprises a first laser diode (5), a second laser diode (6), a third laser diode (7), a fourth laser diode (8), a fifth laser diode (9) and a sixth laser diode (10), the first laser diode (5), the second laser diode (6) and the third laser diode (7) are arranged side by side, and the fourth laser diode (8), the fifth laser diode (9) and the sixth laser diode (10) are arranged side by side; the upper grating structure layer (2) comprises a first upper grating (11), a second upper grating (12), a third upper grating (13), a fourth upper grating (14), a fifth upper grating (15) and a sixth upper grating (16), the first upper grating (11), the second upper grating (12), the third upper grating (13), the fourth upper grating (14), the fifth upper grating (15) and the sixth upper grating (16) are fixedly connected, the first upper grating (11) is arranged in the light path direction of the first laser diode (5), the second upper grating (12) is arranged in the light path direction of the second laser diode (6), the third upper grating (13) is arranged in the light path direction of the third laser diode (7), the fourth upper grating (14) is arranged in the light path direction of the fourth laser diode (8), the fifth upper grating (15) is arranged in the light path direction of the fifth laser diode (9), and the sixth upper grating (16) is arranged in the light path direction of the sixth laser diode (10); the nano grating inertia component structure layer (3) comprises a first frame (17) and a second frame (48), and the first frame (17) and the second frame (48) are arranged side by side; the first frame (17) comprises three square areas, four corners of a first square area of the first frame (17) are vertically fixed with a first driving beam (18), a second driving beam (19), a third driving beam (20) and a fourth driving beam (21) respectively, four corners of a second square area of the first frame (17) are vertically fixed with a fifth driving beam (22), a sixth driving beam (23), a seventh driving beam (24) and an eighth driving beam (25) respectively, and four corners of a third square area of the first frame (17) are vertically fixed with a ninth driving beam (26), a tenth driving beam (27), an eleventh driving beam (28) and a twelfth driving beam (29) respectively.

2. The MEMS inertial measurement unit sensor structure of claim 1, wherein: The first frame (17) is provided with a first mass block (42), a second mass block (43) and a third mass block (44) in three square regions respectively, four corners of the first mass block (42) are fixed with a first detection beam (30), a second detection beam (31), a third detection beam (32) and a fourth detection beam (33) respectively, four corners of the second mass block (43) are fixed with a fifth detection beam (34), a sixth detection beam (35), a seventh detection beam (36) and an eighth detection beam (37) respectively, four corners of the third mass block (44) are fixed with a ninth detection beam (38), a tenth detection beam (39), an eleventh detection beam (40) and a twelfth detection beam (41) respectively.

3. The MEMS inertial measurement unit sensor structure of claim 2, wherein: The second frame (48) includes three square regions, a fourth mass block (61) is connected to the first square region of the second frame (48) through a first folded resonant beam (49), a second folded resonant beam (50), a third folded resonant beam (51) and a fourth folded resonant beam (52), a fifth mass block (62) is connected to the second square region of the second frame (48) through a fifth folded resonant beam (53), a sixth folded resonant beam (54), a seventh folded resonant beam (55) and an eighth folded resonant beam (56), four corners of the third square region of the second frame (48) are connected to a sixth mass block (63) through a ninth folded resonant beam (57), a tenth folded resonant beam (58), an eleventh folded resonant beam (59) and a twelfth folded resonant beam (60).

4. The MEMS inertial measurement unit sensor structure of claim 3, wherein: The first mass block (42) is provided with a first grating (45), the second mass block (43) is provided with a second grating (46), the third mass block (44) is provided with a third grating (47), the fourth mass block (61) is provided with a fourth grating (64), the fifth mass block (62) is provided with a fifth grating (65), and the sixth mass block (63) is provided with a sixth grating (66).

5. The MEMS inertial measurement unit sensor structure of claim 4, wherein: The detector layer (4) includes a first laser detector (67), a second laser detector (68), a third laser detector (69), a fourth laser detector (70), a fifth laser detector (71) and a sixth laser detector (72), the first laser detector (67) is arranged in the light path direction of the first grating (45), the second laser detector (68) is arranged in the light path direction of the second grating (46), the third laser detector (69) is arranged in the light path direction of the third grating (47), the fourth laser detector (70) is arranged in the light path direction of the fourth grating (64), the fifth laser detector (71) is arranged in the light path direction of the fifth grating (65), and the sixth laser detector (72) is arranged in the light path direction of the sixth grating (66).

6. A method of attitude measurement of a MEMS inertial measurement unit sensor structure according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: S1, directly measuring three attitude angles of the carrier according to the data output by the gyroscope, and the relationship between the measured values and the Euler angles satisfies: The respectively represent the angular velocity samples of the three axes of the gyroscope in a specified period, and the , respectively represent the roll angle, the pitch angle and the heading angle. Then the angular rate is converted into the attitude angle size represented by the quaternion; S2, the Z axis of the accelerometer is only affected by its own gravity in the case of being stationary, the rest of the two axis acceleration components are zero, the Z axis component changes in the process of the carrier moving, assuming that the three axis accelerations of the carrier in the moving case are , combining the attitude matrix: ； S3, the attitude rotation matrix is the transformation matrix multiplication of the carrier in the space rotation process, the motion state of the carrier is solved by establishing the attitude transformation matrix, the direction of the carrier in the space is rotated according to The conversion matrix between any two coordinates is expressed by Euler angles and then simplified as follows: Where the Euler angle is expressed as: The , respectively represent the roll angle, the pitch angle and the heading angle of the accelerometer output. S4, combined with the extended Kalman filter algorithm, the model equation is as follows: In each sampling cycle, the angular velocity and acceleration are variables, the sampling values and the initial values of the quaternion are brought into the above formula to realize the continuous updating of the quaternion; the quaternion is converted into Euler angles to represent the attitude angle, and the quaternion The quaternion variable is converted into the cosine matrix through the matrix, and the attitude angle can be calculated. S5, combined with the output data of the attitude solution equation of the gyroscope and accelerometer measurement value, The attitude angle equation expressed by the four variables in the quaternion is obtained from the direction cosine matrix: The , respectively represent the roll angle, the pitch angle and the heading angle of the accelerometer output.

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