Gyro device applied to two-dimensional angular velocity measurement and working method

Abstract

The invention relates to the technical field of gyro angular velocity measurement, in particular to a gyro device applied to two-dimensional angular velocity measurement and a working method, and the gyro device is composed of a fixed grating layer, a movable grating layer and a detector layer. The fixed grating layer is located below an external laser light source, and a two-dimensional grating structure is adopted to achieve double-axis angular velocity synchronous detection. The movable grating layer is arranged below the fixed grating layer, has a two-dimensional grating structure with the same grating period as the fixed grating layer, and can adjust displacement and generate phase shift according to the biaxial angular velocity; and the detector layer is positioned below the movable grating layer, comprises a plurality of detection areas corresponding to the fixed grating layer, and is used for realizing the measurement of the biaxial angular velocity. The device realizes high-precision two-dimensional angular velocity synchronous detection through cooperative work of three layers of structures, is suitable for the fields of inertial navigation, attitude control and the like, and has the characteristics of compact structure and accurate measurement.

Description

Technical Field

[0001] This invention relates to the field of gyroscope angular velocity measurement technology, specifically to a gyroscope device and its working method for two-dimensional angular velocity measurement. Background Technology

[0002] As a core component of inertial technology for measuring angular rate, gyroscopes are widely used in modern industrial control, aerospace and other fields. Grating displacement sensing technology, due to its advantages such as high resolution and strong resistance to electromagnetic interference, is suitable for high-precision MEMS sensors. Its development began with the discovery of diffraction effect in the late 18th century. After continuous research since the 1950s, it has attracted attention in the field of ultra-high precision displacement detection.

[0003] Existing detection methods for micromechanical gyroscopes generally have shortcomings, such as limited accuracy, poor stability, complex manufacturing processes, or difficulty in integration, making it difficult to simultaneously meet the requirements of high precision, high stability, and high integration.

[0004] Currently, there are various detection schemes for micromechanical gyroscopes, with piezoresistive, piezoelectric, and capacitive types being the most commonly used. Among them, capacitive displacement has high resolution and is compatible with MEMS technology, while grating type is suitable for high-precision scenarios due to its high resolution and other advantages. Grating reflection interferometry has high resolution. Meanwhile, in order to improve the accuracy of dual-axis micro-displacement measurement, a scheme using differential output in conjunction with a four-quadrant detector has emerged.

[0005] Existing solutions still have shortcomings: piezoresistive methods have low sensitivity, piezoelectric methods have severe temperature effects, capacitive methods have small dynamic range and are difficult to resist electromagnetic interference, electronic tunneling methods have complex processes, and fiber optic methods have high costs and are difficult to miniaturize; grating reflection interference methods have complex optical paths and are difficult to integrate, differential output schemes have complex signal calculations, and the reduction of grating width / pitch under high precision requirements increases the difficulty of manufacturing processes, and the off-plane driving of in-plane dual-axis detection also needs to be overcome. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a gyroscope device and its working method for two-dimensional angular velocity measurement, which addresses the shortcomings of the prior art and solves the technical problems of low sensitivity of piezoresistive gyroscopes, severe temperature effects of piezoelectric gyroscopes, and small dynamic range and difficulty in resisting electromagnetic interference of capacitive gyroscopes.

[0007] The objective of this invention is achieved through the following technical solutions: In a first aspect, the present invention provides a gyroscope device for two-dimensional angular velocity measurement, comprising, in sequence, a fixed grating layer, a movable grating layer, and a detector layer; The fixed grating layer is disposed below the external laser source and includes a two-dimensional grating structure, used to realize synchronous detection of dual-axis angular velocity; The movable grating layer is disposed below the fixed grating layer and includes a two-dimensional grating structure. The two-dimensional grating structure has the same grating period as the fixed grating layer and is used to adjust the displacement of the two-dimensional grating structure according to the dual-axis angular velocity, thereby generating a phase shift. The detector layer is disposed below the movable grating layer and includes several detection areas corresponding to the fixed grating layer. These detection areas are used to measure dual-axis angular velocity. As a further improvement of the present invention, the fixed grating layer includes a glass substrate and a metal grating disposed on the glass substrate; the metal grating is divided into four grating regions; the grating distribution periods along the X and Y axes of the four grating regions are the same.

[0008] As a further improvement of the present invention, the movable grating layer includes a MEMS structure, the MEMS structure including an outer support frame, a movable mass block and a central sensitive mass block; The movable mass block is connected to the support frame via a drive beam; the central sensitive mass block is connected to the movable mass block via a detection support beam; the Z-axis thickness of the drive beam is less than the X / Y-axis thickness, driving the movable mass block to vibrate along the Z-axis.

[0009] As a further improvement of the present invention, the detection support beam includes an X-direction support beam and a Y-direction support beam; The thickness of the X-direction support beam in the Y direction is greater than its thickness in the X direction, which drives the central sensitive mass block to generate an X-direction displacement. The thickness of the Y-direction support beam in the X direction is greater than its thickness in the Y direction, which drives the central sensitive mass block to generate a Y-direction displacement.

[0010] As a further improvement of the present invention, the movable grating layer includes a movable grating disposed on the sensitive mass block at the center of the MEMS structure and a driving coil surrounding the movable mass block in the MEMS structure; when there is an X-direction Coriolis force, the X-direction support beam bends and causes the movable grating to displace along the X-direction; when there is a Y-direction Coriolis force, the Y-direction support beam bends and causes the movable grating to displace along the Y-direction.

[0011] As a further improvement of the present invention, the detector layer includes a substrate, four-quadrant detection regions disposed on the substrate, and a permanent magnet for providing a magnetic field for the drive coil; the light intensity signals received by the four detection regions of the detector layer are output differentially to calculate the angular velocities of the X-axis and Y-axis; the permanent magnet provides a magnetic field perpendicular to the plane of the drive coil, so that the drive mass block is subjected to a Lorentz force in the Z direction when current is applied.

[0012] As a further improvement of the present invention, the light field distribution of the four quadrant detection regions is expressed as follows:

[0013] In the formula, This is the total transmittance function of the first detection region in the four-quadrant detection region superimposed with the movable grating. This is the total transmittance function of the second detection region in the four-quadrant detection region superimposed with the movable grating. This is the total transmittance function after the third detection region in the four-quadrant detection region is superimposed with the movable grating. This is the total transmittance function of the fourth detection region in the four-quadrant detection region superimposed with the movable grating. To fix the coordinates within the grating plane, To fix the grating in The cycle of direction, To fix the grating in The cycle of direction, For the movable grating relative to the fixed grating in Micro-displacement in direction, For the movable grating relative to the fixed grating in Micro displacement in direction As a further improvement of the present invention, the light intensities received by the four-quadrant detection regions are as follows:

[0014] In the formula, This represents the light intensity of the first detection region within the four-quadrant detection area. This represents the light intensity of the second detection region within the four-quadrant detection area. This represents the light intensity of the third detection region within the four-quadrant detection area. The light intensity is the light intensity of the fourth detection area in the four-quadrant detection region.

[0015] As a further improvement of the present invention, the external laser source is a monochromatic plane wave laser source, used to provide an incident light field that satisfies the Talbot effect.

[0016] Secondly, the present invention provides a method for operating a gyroscope device corresponding to the above-mentioned application in two-dimensional angular velocity measurement, comprising: When an alternating current is applied to the drive coil, the drive mass block, under the influence of the magnetic field of the permanent magnet, causes the central sensitive mass block to resonate along the Z-axis. When there is an input X-axis angular velocity, the Coriolis force causes the sensitive mass block to produce a Y-axis displacement; when there is an input Y-axis angular velocity, the Coriolis force causes the sensitive mass block to produce an X-axis displacement. The light intensity signal is detected by a four-quadrant detector, and the displacement of the movable grating relative to the fixed grating is decoupled by differential operation, and then the dual-axis angular rate is calculated.

[0017] The beneficial effects of this invention are as follows: This invention provides a gyroscope device for two-dimensional angular velocity measurement. It consists of a fixed grating layer, a movable grating layer, and a detector layer arranged sequentially. The fixed grating layer is located below an external laser source and has a two-dimensional grating structure used for synchronous detection of dual-axis angular velocities. The movable grating layer is located below the fixed grating layer, and its two-dimensional grating structure has the same grating period as the fixed grating layer. It can adjust the displacement of its own two-dimensional grating structure according to the dual-axis angular velocity to generate a phase shift. The detector layer is located below the movable grating layer and has several detection areas corresponding to the fixed grating layer. These detection areas are used to measure the dual-axis angular velocity. Based on this sequentially arranged three-layer structure, the two-dimensional grating structure of the fixed grating layer first lays the foundation for synchronous detection of dual-axis angular velocities. Then, the movable grating layer adjusts its displacement according to the dual-axis angular velocity to generate a phase shift, reflecting the change in angular velocity. Finally, the corresponding detection areas of the detector layer acquire the angular velocity information associated with this phase shift, thereby achieving dual-axis angular velocity measurement and producing a stable technical effect for synchronous detection and measurement of dual-axis angular velocities. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the gyroscope device used for two-dimensional angular velocity measurement in an embodiment of the present invention; Figure 2 This is a top view of the fixed grating layer in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the movable grating layer in an embodiment of the present invention; Figure 4 This is a top view of the movable grating layer in an embodiment of the present invention; Figure 5 This is a top view of the detector structure layer in an embodiment of the present invention; Figure 6 This is a simulation result of MATLAB modeling this process in an embodiment of the present invention; Figure 7 This is the mode shape of the sensitive mass block subjected to the X-direction Coriolis force in an embodiment of the present invention; Figure 8 This is the mode shape of the sensitive mass block subjected to a Y-direction Coriolis force in an embodiment of the present invention; Figure 9 This is a graph showing the relationship between the detected mass block and the input angular velocity in an embodiment of the present invention; In the figure, 1. Light source; 2. First metal grating; 3. Glass substrate; 4. Second metal grating; 5. Driving coil; 6. MEMS structure; 7. Driving support beam; 8. First detection support beam; 9. Second detection support beam; 10. Substrate; 11. Permanent magnet; 12. Detection area; 2a. First grating region; 2b. Second grating region; 2c. Third grating region; 2d. Fourth grating region; 4a. Fifth grating region; 4b. Sixth grating region; 4c. Seventh grating region; 4d. Eighth grating region; 7a. First drive support beam; 7b. Second drive support beam; 7c. Third drive support beam; 7d. Fourth drive support beam; 8a. First detection support beam; 8b. Second detection support beam; 8c. Third detection support beam; 8d. Fourth detection support beam; 9a. Fifth detection support beam; 9b. Sixth detection support beam; 9c. Seventh detection support beam; 9d. Eighth detection support beam; 12a. First detection region; 12b. Second detection region; 12c. Third detection region; 12d. Fourth detection region. Detailed Implementation

[0020] To make the objectives and technical solutions of this invention clearer and easier to understand, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. The described embodiments are only some embodiments of the present invention, and not all embodiments.

[0022] Example 1 This embodiment provides a gyroscope device for two-dimensional angular velocity measurement, which includes a fixed grating layer, a movable grating layer, and a detector layer.

[0023] A fixed grating layer, positioned below the external laser source 1, comprises a two-dimensional grating structure for synchronous detection of dual-axis angular velocity. The fixed grating layer includes a glass substrate 3 and a first metal grating 2 disposed on the glass substrate 3. The first metal grating 2 is divided into four grating regions; the grating distribution periods along the X and Y axes are identical for all four grating regions. The glass substrate 3 provides a stable mounting support for the first metal grating 2. The four grating regions divided by the first metal grating 2 meet the requirements of dual-axis angular velocity detection for different grating regions. Maintaining the same grating distribution period along both the X and Y axes ensures consistent grating structural characteristics in each region along the corresponding axis, avoiding signal deviations caused by differences in grating periods between different regions. This provides a structurally stable and consistent grating foundation for dual-axis angular velocity detection, resulting in the technical effect of ensuring the stability and consistency of the grating signal during dual-axis angular velocity detection and improving the reliability of dual-axis angular velocity detection.

[0024] Among them, the external laser source 1 is a monochromatic plane wave laser source 1, which is used to provide an incident light field that satisfies the Talbot effect.

[0025] A movable grating layer is disposed below the fixed grating layer and includes a two-dimensional grating structure. The two-dimensional grating structure has the same grating period as the fixed grating layer and is used to adjust the displacement of the two-dimensional grating structure according to the dual-axis angular velocity, thereby generating a phase shift.

[0026] The movable grating layer includes a MEMS structure 6, which includes an outer support frame, a movable mass block, and a central sensitive mass block. The movable mass block is connected to the support frame via a drive beam. The central sensitive mass block is connected to the movable mass block via a first detection support beam 8 and a second detection support beam 9. The drive beam drives the support beam 7 to have a Z-axis thickness that is less than its X / Y-axis thickness, thereby driving the movable mass block to vibrate along the Z-axis. The outer support frame provides the installation support foundation for the MEMS structure 6. The drive support beam 7 utilizes the structural characteristic that the thickness in the Z direction is less than that in the X / Y directions to drive the vibration of the movable mass block along the Z-axis. The movable mass block drives the central sensitive mass block to move synchronously through the first detection support beam 8 and the second detection support beam 9. At the same time, the two-dimensional grating structure, relying on the same grating period as the fixed grating layer, adjusts its own displacement according to the movement of the MEMS structure 6 under the action of dual-axis angular velocity to generate phase shift. Thus, through the synergistic effect of the various components of the MEMS structure 6 and the specific thickness design of the drive beam, the stability and controllability of the movable mass block's vibration along the Z-axis are ensured. Combined with the precise adjustment of displacement by the two-dimensional grating structure with the same grating period, the accuracy of phase shift generation is guaranteed, providing a reliable phase shift signal for dual-axis angular velocity detection.

[0027] The first detection support beam 8 includes X-direction support beams 8a, 8c, 9b, and 9d, and the second detection support beam 9 includes Y-direction support beams 8b, 8d, 9a, and 9c. The Y-direction thickness of the X-direction support beams 8a, 8c, 9b, and 9d is greater than the X-direction thickness, which drives the central sensitive mass block to generate X-direction displacement. The X-direction thickness of the Y-direction support beams 8b, 8d, 9a, and 9c is greater than the Y-direction thickness, which drives the central sensitive mass block to generate Y-direction displacement.

[0028] The movable grating layer includes a movable grating disposed on the sensitive mass block at the center of the MEMS structure 6 and a drive coil 5 surrounding the movable mass block in the MEMS structure 6; when there is an X-direction Coriolis force, the X-direction support beams 8a, 8c, 9b, and 9d bend and drive the movable grating to move along the X-direction; when there is a Y-direction Coriolis force, the Y-direction support beams 8b, 8d, 9a, and 9c bend and drive the movable grating to move along the Y-direction.

[0029] The drive coil 5 surrounding the movable mass block in the MEMS structure 6 provides the basic operating conditions for the movement of the movable grating layer. When an external force generates an X-axis Coriolis force, the X-axis support beams 8a, 8c, 9b, and 9d will bend and deform. This bending deformation can directly drive the movable grating connected to the central sensitive mass block of the MEMS structure 6 to move along the X-axis. Similarly, when there is a Y-axis Coriolis force, the bending of the Y-axis support beams 8b, 8d, 9a, and 9c can drive the movable grating to move along the Y-axis, realizing the directional displacement adjustment of the movable grating according to the Coriolis force in different directions. This results in the precise control of the movable grating's displacement along the X or Y direction by relying on the linkage between the Coriolis force and the bending of the corresponding support beams 8 and 9. This provides accurate displacement support for the movable grating layer to generate phase shift according to the dual-axis angular velocity, ensuring the accuracy of the phase shift signal during the dual-axis angular velocity detection process.

[0030] The detector layer is located below the movable grating layer and includes several detection areas 12 corresponding to the fixed grating layer. The several detection areas 12 are used to realize the measurement of dual-axis angular velocity.

[0031] The detector layer includes a substrate 10, four-quadrant detection regions 12 disposed on the substrate 10, and a permanent magnet 11 for providing a magnetic field for the drive coil 5; the light intensity signals received by the four detection regions 12 of the detector layer are output differentially to calculate the angular velocities of the X-axis and Y-axis; the permanent magnet 11 provides a magnetic field perpendicular to the plane of the drive coil 5, so that the drive mass block is subjected to a Z-direction Ampere force when current is applied. The substrate 10 provides a stable mounting support for the four-quadrant detection area 12 and the permanent magnet 11. The permanent magnet 11 provides a magnetic field perpendicular to the plane of the drive coil 5. When current is applied to the drive coil 5, the interaction between the magnetic field and the current causes the drive mass to obtain a Lorentz force in the Z direction to achieve drive. The four-quadrant detection area 12 receives the light intensity signal and transmits the signal in a differential output manner, and then completes the calculation of the X-axis and Y-axis angular rates based on the differential signal. This results in the technical effect of relying on the substrate 10 to ensure structural stability, providing a reliable Z-axis driving force for the drive mass through the cooperation of the permanent magnet 11 and the current, and realizing accurate calculation of the X-axis and Y-axis angular rates by utilizing the differential output of the four-quadrant detection area 12. This provides stable support, reliable drive and accurate angular rate data for dual-axis angular velocity detection.

[0032] The light field distributions of the four quadrant detection regions are respectively represented as follows:

[0033] In the formula, This is the total transmittance function of the first detection region in the four-quadrant detection region superimposed with the movable grating. This is the total transmittance function of the second detection region in the four-quadrant detection region superimposed with the movable grating. This is the total transmittance function after the third detection region in the four-quadrant detection region is superimposed with the movable grating. This is the total transmittance function of the fourth detection region in the four-quadrant detection region superimposed with the movable grating. To fix the coordinates within the grating plane, To fix the grating in The cycle of direction, To fix the grating in The cycle of direction, For the movable grating relative to the fixed grating in Micro-displacement in direction, For the movable grating relative to the fixed grating in Micro-displacement in direction.

[0034] The light intensities received by the four quadrant detection regions are as follows:

[0035] In the formula, This represents the light intensity of the first detection region within the four-quadrant detection area. This represents the light intensity of the second detection region within the four-quadrant detection area. This represents the light intensity of the third detection region within the four-quadrant detection area. The light intensity is the light intensity of the fourth detection area in the four-quadrant detection region.

[0036] In this embodiment, the fixed grating layer receives an external laser source through its two-dimensional grating structure and realizes synchronous detection of dual-axis angular velocity. At the same time, the movable grating layer is relative to the fixed grating layer based on the same two-dimensional grating structure to generate a phase shift. Then, the detector layer uses the detection area to detect the phase shift and realize the measurement of dual-axis angular velocity, thereby effectively realizing high-precision synchronous detection of dual-axis angular velocity.

[0037] Example 2 This embodiment provides a specific implementation of a gyroscope device applied to two-dimensional angular velocity measurement. A principle block diagram is shown below. Figure 1 As shown, the two-dimensional grating device for angular rate measurement includes a laser source, a fixed grating layer, a movable grating layer, a detector layer, etc. The functions and working processes of each component are described below.

[0038] In the fixed grating layer, when a plane wave is incident perpendicularly onto the grating plane, an image of the grating will appear in the optical self-imaging diffraction field below the grating. By designing grating distributions with different periods along the X and Y directions, and introducing half-period misalignment in the four regions, a specific distribution of light field is formed below the fixed grating layer after the light passes through it.

[0039] Top view of fixed raster layer as shown Figure 2 As shown, the fixed grating layer consists of a metal grating 2 and a glass substrate 3. Four grating regions, 2a, 2b, 2c, and 2d, are implemented, with the same grating distribution periods along the X and Y axes, respectively, being Dx and Dy. Specifically, the grating distribution in region 2b is the same as that in region 2a along the Y axis, but the grating along the X axis is offset by half a period, Dx / 2; the grating in region 2c is offset from that in region 2a by half a period, Dx / 2 and Dy / 2, along both the X and Y axes; and the grating distribution in region 2d is the same as that in region 2a along the X axis, but the grating along the Y axis is offset by half a period, Dy / 2.

[0040] In the movable grating layer, the fixed grating layer has the same grating period in both the X and Y directions, but there is no misalignment. After light passes through, it reaches the detector layer, enabling the detection of transmitted light intensity. When the movable grating layer is displaced by the Coriolis force generated by the angular rate input, the signal change detected in the corresponding area will produce a 180° phase shift.

[0041] Movable grating layer such as Figure 3As shown, the structure mainly includes a movable grating 4, a MEMS structure 6, and a drive coil 5. The movable mass in the MEMS structure is connected to the edge fixed frame via drive support beams 7 (including the first to fourth drive support beams 7a, 7b, 7c, and 7d). The drive support beams 7 are designed to be thinner in the Z-direction. When the drive coil 5 generates a driving force under the combined action of a magnetic field and current, the drive support beam 7 will bend in the Z-direction, causing the movable mass to vibrate in the Z-direction. The drive coil 5 surrounds the movable mass and is led out to electrodes on the fixed frame via the drive support beams 7. A top view of the movable grating layer is shown below. Figure 4 As shown, the movable grating 4 and the grating structure 1 on the fixed grating have the same Dx and Dy, but there is no misalignment. The movable grating 4 is placed on the central sensitive mass block and is connected to the driving mass block through the detection support beams 8 (including 8a, 8b, 8c, 8d) and support beams 9 (including 9a, 9b, 9c, 9d). The support beams 8a, 8c, 9b, and 9d are designed to be thinner in the X direction. When an X-direction Coriolis force is generated, the sensitive mass block will drive the movable grating 4 to move in the X direction. The support beams 8b, 8d, 9a, and 9c are designed to be thinner in the Y direction. When a Y-direction Coriolis force is generated, the sensitive mass block will drive the movable grating 4 to move in the Y direction. The driving mass block is connected to the outer support frame through the driving support beams 7a, 7b, 7c, and 7d. A driving wire 5 is placed on the driving mass block. By energizing it, it is subjected to a force in the magnetic field, providing driving force for the structure.

[0042] The detector layer is used to detect the intensity of transmitted light and convert the optical signal into an electrical signal. A top view of the detector structure layer is shown below. Figure 5 As shown, corresponding to the four regions 2a, 2b, 2c, and 2d of the grating layer, four detection regions 12a, 12b, 12c, and 12d are designed. A permanent magnet 11 is placed on the substrate 10 to provide a magnetic field for the drive coil 5 on the MEMS structure 6. The four detection regions 12a, 12b, 12c, and 12d are coaxial with the center of the light source and the fixed grating layer. A permanent magnet 11 is also placed there to provide a magnetic field for the drive coil 5.

[0043] When a laser beam is incident perpendicularly onto the plane of a fixed grating, a specific light field is formed below the fixed grating layer by designing a grating distribution with different periods along the X and Y directions. After passing through the fixed grating, the laser beam reaches the movable grating layer. As the movable grating shifts, the light signal passing through it also changes accordingly. Due to the specific misalignment of the grating on the fixed grating, the light intensity signals received by the four detection areas of the detection layer will differ during the displacement of the movable grating, resulting in a corresponding phase shift in the generated electrical signals. Denoising, amplification, and readout of the X and Y axis signals are achieved through differential signal output.

[0044] The Talbot effect refers to the phenomenon where, when a monochromatic plane wave is incident perpendicularly on a periodic object, an image of the object appears at periodic distances behind it. Assume the complex amplitude (wavefront) of the incident light is... The transmittance function of the grating is The complex amplitude function of the light wave distribution immediately behind the grating is equal to the product of the transmittance function and the complex amplitude of the input light.

[0045] In this invention, after a plane wave passes through a fixed grating layer, it forms a periodic image behind it. The movable grating layer is placed at its Tuber distance z1, i.e. The diffraction transfer function to the surface of the movable grating can then be expressed as:

[0046] Therefore, at the Tuber distance, the transfer function is 1, resulting in an image that repeats the fixed grating. The light field distribution at this location is the same as the transmittance function of the fixed grating. The transmittance function of the movable grating is... Similarly, if a detector layer is placed at the Talbot distance behind the movable grating, the expression for the light field distribution on the detector surface can be written as:

[0047] The transmission function of a two-dimensional grating can be written as the product of the transmission functions of two one-dimensional gratings. The principle is explained using sign and sine functions to represent the projection function. The transmission function of a fixed grating can be written in sign function form. The distribution of the transmission function in the four quadrants with misalignment can be represented as follows:

[0048] Similarly, when the movable grating undergoes relative displacement with the fixed grating under the action of the Coriolis force, and the coordinates are unified, its transmission function can be written as:

[0049] According to the Talbot effect, the light field distribution in the four quadrants reaching the detector surface can be expressed as:

[0050] In the formula, This is the total transmittance function of the first detection region in the four-quadrant detection region superimposed with the movable grating. This is the total transmittance function of the second detection region in the four-quadrant detection region superimposed with the movable grating. This is the total transmittance function after the third detection region in the four-quadrant detection region is superimposed with the movable grating. This is the total transmittance function of the fourth detection region in the four-quadrant detection region superimposed with the movable grating. To fix the coordinates within the grating plane, To fix the grating in The cycle of direction, To fix the grating in The cycle of direction, For the movable grating relative to the fixed grating in Micro-displacement in direction, For the movable grating relative to the fixed grating in Micro-displacement in direction.

[0051] Based on the distribution expression, the light intensity received by the four-quadrant detector can be expressed as:

[0052] In the formula, This represents the light intensity of the first detection region within the four-quadrant detection area. This represents the light intensity of the second detection region within the four-quadrant detection area. This represents the light intensity of the third detection region within the four-quadrant detection area. This represents the light intensity of the fourth detection region within the four-quadrant detection area. Further calculations are performed:

[0053] Since the size of the detector integration region is fixed and the areas in all four quadrants are the same, containing multiple grating periods, the following factors in the formula are affected by... and The effect is very small and can be considered a constant:

[0054] Furthermore, we can obtain:

[0055] It can be seen that by differentially superimposing the signals obtained from 12a, 12b, 12c, and 12d, the decoupling and separation of dual-axis micro-displacement can be achieved. By finally solving the output signal, the displacement components of the X-axis and Y-axis can be obtained respectively, and finally the magnitude of the input angular rate of each axis can be calculated, thereby realizing the simultaneous measurement of dual-axis angular rate.

[0056] A model is built in COMSOL. By applying a voltage to the driving wire, a force is generated in the magnetic field, providing the driving force for the structure. The driving mode shape of the structure is as follows: Figure 6 As shown. Figure 7 , Figure 8The mode shapes of the sensitive mass block under X-axis and Y-axis Coriolis forces are shown respectively. When the MEMS gyroscope is working, the driving mass block drives the detection mass block to resonate in the Z-axis direction under the action of the driving wire and magnetic field. When there is a Y-axis angular velocity input, based on the Coriolis principle, the detection mass block and the movable grating 4 undergo relative displacement in the X-axis with the upper light source 1, the fixed grating 3 and the lower detector 12, and the detection support beams 8a, 8c, 9b and 9d bend. When there is an X-axis angular velocity input, based on the Coriolis principle, the detection mass block and the movable grating 4 undergo relative displacement in the Y-axis with the upper light source 1, the fixed grating 3 and the lower detector 12, and the detection support beams 8b, 8d, 9a and 9c bend.

[0057] A fixed voltage is applied to the driving wire in the model, and multiphysics simulation is performed under the action of a magnetic field. The input angular velocities along the X and Y axes are scanned to obtain the relationship between the detected mass block and the input angular velocity, as shown below. Figure 9 As shown, due to the high symmetry of the designed structure, its structural sensitivity in both directions is similar and linearly related to the input angular rate, which is consistent with the theory. Through the preceding grating design, the displacement of the detection mass block caused by the Coriolis force can be decoupled and calculated, ultimately realizing the measurement of the input angular rate of each axis and achieving the sensor function.

[0058] This embodiment designs a staggered grating array with a fixed grating layer to form a specific light field distribution below it. When the movable grating is displaced, the changes in transmitted light intensity detected in the four detector regions have a corresponding phase shift. By differentially analyzing the signals in the corresponding regions, the corresponding components of the X-axis and Y-axis can be calculated.

[0059] Example 3 Based on the gyroscope device used for two-dimensional angular velocity measurement in Embodiments 1 and 2, this embodiment provides a method for operating the gyroscope device, which specifically includes the following steps: When an alternating current is applied to the drive coil, the drive mass block, under the influence of the magnetic field of the permanent magnet, causes the central sensitive mass block to resonate along the Z-axis. When an input angular velocity is present, the Coriolis force causes the sensitive mass block to produce a Y-direction displacement; when an input angular velocity is present, the Coriolis force causes the sensitive mass block to produce an X-direction displacement. The light intensity signal is detected by a four-quadrant detector, and the displacement of the movable grating relative to the fixed grating is decoupled by differential operation, and then the dual-axis angular rate is calculated.

Claims

1. A gyro device applied to two-dimensional angular velocity measurement, characterized by, The fixed grating layer, the movable grating layer and the detector layer are sequentially arranged; The fixed grating layer is arranged below the external laser light source and comprises a two-dimensional grating structure for realizing synchronous detection of double-axis angular velocity. The movable grating layer is arranged below the fixed grating layer and comprises a two-dimensional grating structure, which has the same grating period as the fixed grating layer, for adjusting the displacement of the two-dimensional grating structure according to the double-axis angular velocity and further generating phase shift. The detector layer is arranged below the movable grating layer and comprises a plurality of detection regions corresponding to the fixed grating layer, and the plurality of detection regions are used for realizing measurement of the double-axis angular velocity.

2. A gyroscopic device for two-dimensional angular velocity measurement according to claim 1, characterized in that The fixed grating layer comprises a glass substrate and a first metal grating arranged on the glass substrate; the first metal grating is divided into four grating regions; the X-axis and Y-axis grating distribution periods of the four grating regions are the same.

3. The gyroscopic device for two-dimensional angular velocity measurement according to claim 1, characterized in that The movable grating layer comprises a MEMS structure, and the MEMS structure comprises a peripheral support frame, a movable mass and a central sensitive mass. The movable mass is connected with the support frame through a driving beam; the central sensitive mass is connected with the movable mass through a detection support beam; the Z-direction thickness of the driving beam is smaller than the X / Y-direction thickness, and the driving beam drives the movable mass to vibrate along the Z axis.

4. A gyroscopic device for two-dimensional angular velocity measurement according to claim 3, characterized in that The detection support beam comprises an X-direction support beam and a Y-direction support beam. The Y-direction thickness of the X-direction support beam is greater than the X-direction thickness, and the X-direction support beam drives the central sensitive mass to generate X-direction displacement. The X-direction thickness of the Y-direction support beam is greater than the Y-direction thickness, and the Y-direction support beam drives the central sensitive mass to generate Y-direction displacement.

5. A gyroscopic device for two-dimensional angular velocity measurement according to claim 4, characterized in that The movable grating layer comprises a movable grating arranged on the central sensitive mass of the MEMS structure and a driving coil surrounding the movable mass of the MEMS structure; when the X-direction Coriolis force exists, the X-direction support beam bends to drive the movable grating to displace along the X direction; when the Y-direction Coriolis force exists, the Y-direction support beam bends to drive the movable grating to displace along the Y direction.

6. A gyroscopic device for two-dimensional angular velocity measurement according to claim 5, characterized in that The detector layer comprises a substrate, four-quadrant detection regions arranged on the substrate, and a permanent magnet for providing a magnetic field for the driving coil; the light intensity signals received by the four detection regions of the detector layer are output through difference, and are used for calculating the X-axis and Y-axis angular rates; the permanent magnet provides a magnetic field perpendicular to the plane of the driving coil, so that the driving mass is subjected to Z-direction Ampere force when current is passed.

7. A gyroscopic device for two-dimensional angular velocity measurement according to claim 6, characterized in that The light field distribution of the four-quadrant detection regions is respectively represented as: wherein Ttot(1) is the total transmittance function of the first quadrant of the detection area superimposed with the movable grating, Ttot(2) is the total transmittance function of the second quadrant of the detection area superimposed with the movable grating, Ttot(3) is the total transmittance function of the third quadrant of the detection area superimposed with the movable grating, Ttot(4) is the total transmittance function of the fourth quadrant of the detection area superimposed with the movable grating, x is the coordinate in the plane of the fixed grating, T is the period of the fixed grating in the direction, T is the period of the fixed grating in the direction, dx is the micro-displacement of the movable grating relative to the fixed grating in the direction, dx is the micro-displacement of the movable grating relative to the fixed grating in the direction.

8. A gyroscopic device for two-dimensional angular velocity measurement according to claim 7, characterized in that The light intensity received by the four-quadrant detection regions is respectively: wherein is the light intensity in the first detection region of the four-quadrant detection region, is the light intensity in the second detection region of the four-quadrant detection region, is the light intensity in the third detection region of the four-quadrant detection region, is the light intensity in the fourth detection region of the four-quadrant detection region.

9. The gyroscopic device for two-dimensional angular velocity measurement according to claim 1, characterized in that, The external laser light source is a monochromatic plane wave laser light source for providing incident light field satisfying the Talbot effect.

10. A method of operating a gyroscopic device for two-dimensional angular velocity measurement according to any one of claims 1 to 9, characterized in that The method comprises the following steps: Passing an alternating current to the driving coil, under the action of the magnetic field of the permanent magnet, the driving mass drives the central sensitive mass to resonate along the Z axis; When the input X-axis angular rate exists, the Coriolis force makes the sensitive mass displace along the Y direction; when the input Y-axis angular rate exists, the Coriolis force makes the sensitive mass displace along the X direction; The light intensity signals are detected by the four-quadrant detector, and the displacement of the movable grating relative to the fixed grating is decoupled through difference operation, and the double-axis angular rate is calculated.

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