Spherical multi-dimensional rotation angular displacement sensor and concentricity detection and adjustment method thereof

Abstract

The invention discloses a spherical multi-dimensional rotation angular displacement sensor and a base body concentricity detection and adjustment method thereof, the sensor comprises a stator base body and a rotor base body, the stator base body is in a spherical shell shape, the rotor base body is in a spherical shape and is located in the stator base body, and a gap is formed between the outer surface of the rotor base body and the inner surface of the stator base body; an excitation unit is arranged on the outer surface of the rotor base body; three groups of induction units which are symmetrically arranged in three directions of a three-dimensional coordinate system of the stator base body at intervals are arranged on the inner surface of the stator base body, each group of induction units comprises at least one pair of induction electrodes, the shapes and the sizes of the induction electrodes are completely the same, and the distances from the centers of the induction electrodes to the sphere center of the stator base body are equal. When concentricity detection is carried out on the stator base body and the rotor base body, differential voltage signals of the induction electrodes on the stator base body in the preset direction are collected; and the spatial position of the rotor base body is adjusted in real time according to the polarity and amplitude of the differential voltage signal.

Description

Technical Field

[0001] This invention relates to the field of sensor calibration, specifically to a spherical multidimensional rotational angular displacement sensor and its concentricity detection and adjustment method. Background Technology

[0002] Currently, spherical multidimensional rotation angle measurement sensors have shown broad application prospects and have been widely used in fields such as robotics and aerospace due to their unique spatial attitude perception capabilities.

[0003] Existing spherical sensors mainly consist of a stator base and a rotor base. An excitation unit is mounted on the stator base, and a sensing unit is mounted on the rotor base. The stator base is spherical, and the rotor base is spherical and located within the stator base's spherical shell. A gap exists between the surface of the rotor base and the inner surface of the stator base, allowing the rotor base to be suspended and concentric with the stator base. Based on the structure of existing spherical sensors, the measurement accuracy for precisely detecting the multidimensional rotational motion of an object fundamentally depends on the precise coaxial mounting, i.e., concentricity, between the stator base and the rotor base.

[0004] However, existing spherical sensors generally suffer from a key limitation: their structural design typically lacks a built-in concentricity monitoring function that allows direct determination or feedback of whether the stator and rotor base concentricity meets requirements through internally generated electrical signals. Specifically, to ensure concentricity, current methods generally rely on external auxiliary measurement devices such as high-precision laser interferometers or other independent displacement sensors. This auxiliary measurement method not only significantly increases the complexity of system integration and operational procedures but also results in high overall implementation costs due to the need for precision specialized measuring instruments. Summary of the Invention

[0005] To address the aforementioned shortcomings of existing technologies, the present invention aims to provide a spherical multidimensional rotational angular displacement sensor and a method for detecting and adjusting the concentricity of its substrate, thereby solving the problem that existing spherical sensors cannot directly and cost-effectively detect the concentricity between the stator substrate and the rotor substrate.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A spherical multidimensional rotational angular displacement sensor includes a stator base and a rotor base. The stator base is spherical, and the rotor base is spherical and located within the spherical shell of the stator base; the two are concentrically arranged. A radial gap exists between the surface of the rotor base and the inner surface of the stator base, allowing the rotor base to be suspended. An excitation unit is provided on the outer surface of the rotor base, which is a layer of spherical excitation electrodes covering the outer surface of the rotor base. Three sets of sensing units are provided on the inner surface of the stator base, symmetrically arranged at intervals in three directions of the three-dimensional coordinate system of the stator base. Each set of sensing units includes at least one pair of sensing electrodes. All sensing electrodes have the same shape and size, and the distance from the center of each sensing electrode to the center of the stator base sphere is equal. In this way, the excitation unit is located on the outer surface of the rotor substrate, and the excitation unit consists of an excitation electrode that completely covers the rotor substrate. Compared with existing sensor structures, this setup requires fewer excitation electrodes but covers a larger area. After applying a low-frequency electrical excitation signal to the excitation electrode, the generated electric field can fill the space between the stator substrate and the rotor substrate. Multiple induction signals can be formed through electric field coupling without a one-to-one correspondence between the induction units within the stator substrate, making product installation simpler and faster. Furthermore, the induction units located on the inner surface of the stator substrate are divided into three groups, each corresponding to one of the three directions of the three-dimensional coordinate system. Since the induction electrodes of each group are symmetrically arranged and have the same shape and size, with the same distance from their center to the center of the stator substrate sphere, if the stator substrate and the rotor substrate are concentric, each pair of induction electrodes in the same direction will receive the same amplitude. If the amplitudes are different, it indicates that the stator substrate and the rotor substrate are not concentric. That is, the above sensor structure can acquire the differential electrodes corresponding to each set of sensing signals in three directions in the three-dimensional coordinate system, and then calculate the relative displacement deviation of the center of the rotor base relative to the center of the stator base. This deviation directly characterizes the radial installation concentricity error of the sensor in this direction, and can provide the adjustment direction and adjustment distance for the subsequent adjustment of the rotor base position.

[0008] Furthermore, the excitation electrode is a conductive metal electrode sheet that is tightly attached to the outer surface of the rotor substrate, and its inner diameter is equal to the outer diameter of the rotor substrate; it is a spherical quadrilateral, a spherical circle, or a spherical annulus with a hollow center, and the hollow center portion can be circular, triangular, or polygonal.

[0009] Furthermore, the sensing electrode is provided with 6 electrodes, each occupying an angle of [missing information]. Two induction electrodes are provided on the same coordinate direction inside the stator matrix, and the two induction electrodes are symmetrically distributed.

[0010] Furthermore, the system includes 12 sensing electrodes, each in the shape of a spherical rectangle. Each sensing unit has four sensing electrodes, symmetrically distributed in pairs. This ensures that each stator substrate has four sensing electrodes along the same coordinate direction. The more sensing electrodes there are, the more spatial position information is acquired, resulting in more accurate concentricity detection of the rotor substrate installation.

[0011] A method for detecting and adjusting the concentricity of a spherical multidimensional rotational angular displacement sensor substrate, the method being used to detect and adjust the concentricity of the stator substrate and rotor substrate of the aforementioned spherical multidimensional rotational angular displacement sensor, comprising the following steps: S1, applying a low-frequency sinusoidal electric excitation signal with preset characteristics to the excitation electrodes arranged on the rotor substrate, forming an electric field between the stator substrate and the rotor substrate, and forming a multi-path coupling capacitor between the excitation electrodes on the upper surface of the rotor substrate and the sensing electrodes on the inner surface of the stator substrate; S2, taking the coordinate axis direction where one set of sensing electrodes is located as the first measurement direction, acquiring the differential voltage signal generated by one or two pairs of sensing electrodes symmetrically distributed in a set of sensing units in the corresponding coordinate direction; S3, based on the magnitude and polarity of the differential voltage of the sensing electrodes acquired in S2, determining the current rotational angular displacement in the corresponding coordinate direction. The relative displacement deviation and radial offset direction of the center of the rotor base relative to the dot of the stator base, or the relative displacement deviation and radial offset direction of the dot of the current stator base relative to the dot of the rotor base; S4, according to the relative displacement deviation of the rotor base or stator base in the coordinate direction in S3, adjust the displacement of the rotor base or stator base in the corresponding direction; S5, take the direction orthogonal to the first measurement direction as the second measurement direction, and the direction orthogonal to the second measurement direction as the third measurement direction, and repeat the detection, judgment and adjustment process of S1-S4; S6, repeat the detection, judgment and adjustment process of S1-S5 until the differential voltage signals in the three coordinate directions independently reach and stabilize within their respective preset zero threshold ranges, then it is determined that the theoretical rotation center point of the rotor base has achieved a high degree of coincidence with the preset geometric center point of the stator base in three-dimensional space. In this way, differential voltage signals are first acquired from the corresponding sensing electrodes in each coordinate direction to obtain the magnitude and polarity of the differential voltage. This allows the determination of the relative offset and direction between the stator and rotor bases. Finally, the position of the rotor or stator base is adjusted based on the relative displacement deviation and radial offset direction. By adjusting the three coordinate directions separately using this method, and then repeating the detection and adjustment, the phenomenon of incomplete adjustment due to adjustment deviation after a single adjustment can be avoided. In other words, this method results in higher concentricity accuracy of the adjusted sensors.

[0012] Furthermore, in S1, the amplitude Am of the low-frequency sinusoidal excitation signal is 12V, the frequency f is 40kHz, and the angular frequency ω = 2πf = 8 * 10 4*πrad / s. Thus, using the above frequency and amplitude can meet the signal acquisition conditions and requirements of the sensing unit.

[0013] Furthermore, before testing, a spherical multidimensional rotational angular displacement sensor is assembled on a testing platform. The testing platform is L-shaped or inverted T-shaped, consisting of a horizontal plate and a vertical plate. A base positioning mechanism and a base adjustment mechanism are respectively provided on the vertical and horizontal plates. The base positioning mechanism includes a positioning rod with one end fixedly connected to the vertical plate and the other end fixedly connected to the outer end face of the rotor or stator base. The base adjustment mechanism includes a sliding platform, a lifting motor, and an adjusting rod. The sliding platform has a drive motor connected to each of its two sides (i.e., a drive motor is provided in both the X-axis and Z-axis directions) to achieve left-right and forward-backward movement for positioning. The lifting motor is fixedly mounted on the sliding platform; the lifting motor is a linear motor. The lower end of the adjusting rod is fixedly connected to the end of the push rod of the lifting motor, and the upper end is fixedly connected to the stator or rotor base. When displacement adjustment of the rotor or stator base is required, the corresponding drive motor or lifting motor is activated according to the desired coordinate direction, driving the sliding platform to move or the adjusting rod to rise or fall, thus achieving displacement adjustment. In this way, during adjustment, one of the stator base or rotor base is kept stationary. The offset and direction between the two are detected, and then the displacement of the stator base is adjusted based on the offset and direction of the offset of one base relative to the other. During adjustment, the drive motor can drive the sliding platform to move horizontally in the X and Y directions for positioning, while the lifting motor can drive the adjusting rod to move up and down in the Z direction to achieve adjustment. When using motor adjustment, drive commands can be issued to the corresponding motors according to the offset and direction, achieving precise adjustment with high accuracy.

[0014] Furthermore, the horizontal plate is also provided with a first guide groove and a second guide groove for guiding the sliding platform, and the first guide groove and the second guide groove are arranged vertically. In this way, the guide grooves can guide the sliding platform and make its movement more stable. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural diagram of the spherical multidimensional rotational angular displacement sensor in Example 1;

[0016] Figure 2 This is a schematic cross-sectional view of the spherical multidimensional rotational angular displacement sensor in Example 1;

[0017] Figure 3 This is a schematic diagram showing the relative positional relationship of the induction electrodes on the stator substrate in Example 1;

[0018] Figure 4 This is a schematic diagram showing the relative positional relationship of the excitation electrodes on the rotor base in Example 1;

[0019] Figure 5 This is a schematic diagram of the three-dimensional structure of the stator substrate in Example 1;

[0020] Figure 6 This is a schematic diagram showing the angle occupied by a single induction electrode in the stator substrate in Example 1;

[0021] Figure 7 This is a schematic diagram of the differential voltage signals of the stator substrate in the first, second, and third measurement directions in Example 1;

[0022] Figure 8 This is a schematic diagram of the shape of the induction electrode in the stator substrate in Example 2;

[0023] Figure 9 This is a schematic diagram of the shape of the induction electrode in the stator substrate in Example 3;

[0024] Figure 10 This is a schematic diagram of the shape of the induction electrode in the stator substrate in Example 4;

[0025] Figure 11 This is a schematic diagram of the installation structure in the sensor detection state in Example 1. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0027] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship commonly used when the product is in use. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance. In addition, the terms "horizontal," "vertical," etc., do not indicate that the component is required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" 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 of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0028] like Figures 1-6As shown, this embodiment provides a spherical multidimensional rotational angular displacement sensor, including a stator base 1 and a rotor base 2. The stator base 1 is spherical, and the rotor base 2 is spherical and located inside the spherical shell of the stator base 1. There is a gap between the surface of the rotor base 2 and the inner surface of the stator base 1, so that the rotor base 2 is suspended and concentric with the stator base 1. An excitation unit is provided on the outer surface of the rotor base 2. The excitation unit is a layer of spherical excitation electrodes covering the outer surface of the rotor base 2. Three sets of sensing units are provided on the inner surface of the stator base 1, which are symmetrically arranged at intervals in three directions (x, y, z) of the three-dimensional coordinate system of the stator base 1. Each set of sensing units includes a pair of sensing electrodes. The shape and size of each sensing electrode are the same, and the distance from the center of each sensing electrode to the center of the sphere of the stator base 1 is equal. In this way, the excitation unit is located on the outer surface of the rotor base 2, and the excitation unit consists of only one excitation electrode that completely covers the rotor base 2. Compared with existing sensor structures, this setup requires fewer excitation electrodes and covers a larger area. After applying a low-frequency electrical excitation signal to the excitation electrode, the generated electric field can fill the space between the stator base 1 and the rotor base 2. Multiple induction signals can be formed through electric field coupling without a one-to-one correspondence with the sensing units within the stator base 1, making product installation simpler and faster. Furthermore, the sensing units located on the inner surface of the stator base 1 are divided into three groups, each corresponding to one of the three directions of the three-dimensional coordinate system. Since the sensing electrodes of each group are symmetrically arranged and have the same shape and size, and the distance from their centers to the center of the stator base 1 is also the same, if the stator base 1 and the rotor base 2 are concentric, the amplitude received by each pair of sensing electrodes in the same direction will be equal. If the amplitudes are different, the stator base 1 and the rotor base 2 are not concentric and their positions need to be adjusted. That is, the above-mentioned sensor structure can acquire the differential electrodes corresponding to each set of sensing signals in three directions in the three-dimensional coordinate system, and then calculate the relative displacement deviation of the origin of the current sensor rotor base 2 relative to the origin of the stator base 1. This deviation directly characterizes the radial installation concentricity error of the sensor in this direction, and can provide the adjustment direction and adjustment distance for the subsequent adjustment of the position of the rotor base 2.

[0029] like Figures 5-6As shown, the excitation electrode is a conductive metal electrode sheet tightly attached to the outer surface of the rotor base 2, with its inner diameter equal to the outer diameter of the rotor base 2. There are six sensing electrodes: A, B, C, D, E, and F (i.e., the sensing electrodes are located on the coordinate axes X+, X-, Y+, Y-, Z+, and Z-, respectively, with all six sensing units equidistant from the origin O; specifically, sensing electrodes B and D are symmetrically positioned along the X-axis, A and C are symmetrically positioned along the Y-axis, and E and F are symmetrically positioned along the Z-axis). Each sensing electrode is tightly attached to the inner surface of the stator base 1, and each electrode is a spherical quadrilateral with a central hollowed-out section. The hollowed-out section has a radius of 40mm. This ensures that the excitation electrode is tightly attached to the rotor base 2, guaranteeing concentricity after installation, thus allowing the detection and determination of whether the stator base 1 and rotor base 2 are concentric based on the sensing signal. Two induction electrodes are provided on the same coordinate direction inside the stator base 1, and the two induction electrodes are symmetrically distributed.

[0030] In this embodiment, the distance d between the rotor base 2 and the stator base 1 is 26mm, the radius of the rotor base 2 is set to r´R=50mm, and the thickness of the excitation electrode on the outer surface of the rotor base 2 is dR=2mm. The thickness of the stator base 1 is d'S=10mm, the inner radius of the stator base 1 is r´S=76mm, the outer radius of the stator base 1 is rS=86mm, and the thickness of the induction electrode on the inner surface of the stator base 1 is dS=2mm. Therefore, the angle occupied by a single induction electrode is... .

[0031] In this embodiment, the stator base 1 is rotatably connected to the stator drive turntable via a stator support shaft, and the rotor base 2 is rotatably connected to the rotor drive turntable via a rotor support shaft, with the rotor base suspended within the stator base. The induction electrode is connected to an external excitation source, and the excitation electrode is led out from within the stator base 1 via the stator support shaft. The rotor support shaft and the stator support shaft are perpendicular to each other. This mounting structure is an existing structure and will not be described in detail here.

[0032] This embodiment describes a method for detecting and adjusting the concentricity of the base of a spherical multidimensional rotational angular displacement sensor. This method is used to detect and adjust the concentricity of the stator base 1 and rotor base 2 of the aforementioned spherical multidimensional rotational angular displacement sensor. The method includes the following steps: S1, applying a low-frequency sinusoidal electric excitation signal with preset characteristics to the excitation electrodes arranged on the rotor base 2, forming an electric field between the stator base 1 and the rotor base 2, and forming a multi-path coupling capacitor between the excitation electrodes on the upper surface of the rotor base 2 and the sensing electrodes on the inner surface of the stator base 1; S2, detecting the differential voltage signal, taking the coordinate axis direction where one set of sensing electrodes is located as the first measurement direction (specifically, the X-axis direction is selected as the first measurement direction), and acquiring the differential voltage signal generated by one or two pairs of symmetrically distributed sensing electrodes in a corresponding set of sensing units along this coordinate direction. Ux; S3, based on the magnitude and polarity of the differential voltage of the induction electrode obtained in S2, determine the relative displacement deviation and radial offset direction of the center of the rotor base 2 relative to the dot of the stator base 1 in the corresponding coordinate direction, or the relative displacement deviation and radial offset direction of the dot of the stator base 1 relative to the dot of the rotor base 2; S4, based on the relative displacement deviation of the rotor base 2 or the stator base 1 in the coordinate direction in S3, adjust the displacement of the rotor base 2 or the stator base 1 in the corresponding direction; S5, with the first The direction orthogonal to the measurement direction is taken as the second measurement direction (i.e., the Y-axis direction), and the direction orthogonal to the second measurement direction is taken as the third measurement direction (i.e., the Z-axis direction). The detection, judgment, and adjustment process of S1-S4 is repeated to obtain the result. In S6, the detection, judgment, and adjustment process of S1-S5 is repeated until the differential voltage signals in the three coordinate directions independently reach and stabilize within their respective preset zero threshold ranges. Then, it is determined that the theoretical rotation center point of the rotor base 2 has achieved high overlap with the preset geometric center point of the stator base 1 in three-dimensional space. In this way, differential voltage signals are first collected from the corresponding sensing electrodes in each coordinate direction to obtain the magnitude and model of the differential voltage, and then the relative displacement deviation and radial offset direction of the rotor base 2 are determined. Finally, the position of the rotor base 2 is adjusted according to the relative displacement deviation and radial offset direction. By adjusting the three coordinate directions separately according to the above method and then repeating the detection and adjustment, the phenomenon of incomplete adjustment due to adjustment deviation after a one-time adjustment can be avoided. That is, the concentricity accuracy of the adjusted sensor is higher after adopting this method.

[0033] To facilitate adjustment, one sensor needs to be fixed while the other undergoes three-dimensional displacement adjustment. Therefore, before testing, a spherical multidimensional rotational angular displacement sensor is first assembled on a testing platform 3. The testing platform 3 is L-shaped (in specific implementations, it can also be designed as an inverted T-shape), consisting of a horizontal plate 31 and a vertical plate 32. A base positioning mechanism and a base adjustment mechanism are respectively provided on the vertical plate 32 and the horizontal plate 31. The base positioning mechanism includes a positioning rod 4, one end of which is fixedly connected to the vertical plate, and the other end of which is fixedly connected to the outer end face of the rotor base or stator base. The base adjustment mechanism includes a sliding platform 5, a lifting motor 7, and an adjusting rod 8. The sliding platform 5 has a drive motor 6 connected to each of its two sides (i.e., a drive motor is provided in both the X-axis and Z-axis directions) to achieve left-right and forward-backward movement for positioning. The lifting motor 7 is fixedly installed on the sliding platform; the lifting motor is a linear motor. The lower end of the adjusting rod is fixedly connected to the end of the push rod of the lifting motor, and the upper end is fixedly connected to the stator base or rotor base.

[0034] In this embodiment, the rotor base 2 is fixed in place, and the stator base 1 is used as the main adjustment body. During installation, the positioning rod passes through the hollow part on one side of the stator base 1 and its end is fixedly connected to the rotor base 2 (the fixed connection part avoids the induction electrode plate on the stator base 1). The connection point between the adjusting rod and the stator base 1 is set away from the induction electrode. The adjusting rod and the positioning rod are made of non-conductive materials to avoid affecting the change of the electric field around the induction electrode. During adjustment, the positioning rod passes through the hollow part on one side of the stator base 1 and its end is fixedly connected to the rotor base 2. The adjusting rod is fixedly connected to the stator base 1. Based on the relative displacement deviation and radial offset direction of the point of the stator base 1 relative to the point of the rotor base 2 determined after detection in the first measurement direction, the corresponding displacement offset command and offset direction command are sent to the corresponding drive motor. After receiving the corresponding command, the drive motor drives the sliding platform to move, and then drives the adjusting rod to move together. After that, a second detection and adjustment are performed until the differential voltage signals in the three coordinate directions independently reach and stabilize within their respective preset zero threshold ranges.

[0035] When the excitation electrode is introduced into the rotor base 2, the potential distribution of the rotor base 2 can be expanded through spherical harmonics. Based on the symmetrical arrangement of the induction electrodes on the stator base 1 in this embodiment (the distance from the center of each induction electrode to the center of the stator base 1 is equal, and the shape and size of each induction electrode are the same), we take movement in one direction as the basis for analysis:

[0036] (1)

[0037] In the formula, This represents the spherical coordinate position of a point on the sphere. Indicates the polar angle. It is the azimuth angle. For radius, It is a spherical harmonic function. The canonical components characterizing the potential field are related to the external driving field or boundary conditions. The singular components characterizing the potential field are directly related to the distribution of internal physical sources. Let m be the order of the spherical harmonic function, and m be the orientation quantum number of the spherical harmonic function.

[0038] Since the analysis is performed along the z-axis, m = 0, and the general solution is:

[0039] (2)

[0040] For the related Legendre polynomial; Indicating induced charge First-order feedback coefficient, Representing the excitation charge Source coefficients;

[0041] Boundary conditions:

[0042] a) At r = r'S, since the outer spherical shell is suspended, its total charge is 0, therefore:

[0043] (Constant) (3)

[0044] Expanding the above expression in its second order and matching the corresponding coefficients, we can obtain:

[0045] (4)

[0046] (5)

[0047]

[0048] For the physical model structure discussed in this paper, since the inductive electrodes in other directions are grounded, providing a potential reference for the system, the constants can be used in this physical model. Take 0.

[0049] At r = r´R, the rotor base 2 is an equipotential body, and the excitation voltage amplitude is... When the rotor base 2 is displaced Δd along the z-direction, its surface position is: The boundary conditions can be obtained as follows:

[0050] (6)

[0051] The eccentricity distance along the z-axis is... An angle factor for converting the z-axis of a rectangular coordinate system to a spherical coordinate system.

[0052] Expanding the Taylor formula to the first order, we get:

[0053]

[0054] (7)

[0055] Constant term:

[0056]

[0057] Term coefficient:

[0058]

[0059] Term coefficient:

[0060]

[0061] For the above formula, matching the corresponding coefficients, we can obtain:

[0062] (8)

[0063] (9)

[0064] Charge density on the surface of stator substrate 1:

[0065] Substituting into the potential expression, and retaining only the first-order terms, the first-order terms represent the charge density shift caused by the eccentricity:

[0066] (10)

[0067] In the formula, The charge density of the outer spherical shell when concentric. This represents the charge density of the outer spherical shell disturbance caused by eccentricity.

[0068] Calculate charge

[0069] Utilizing the spherical symmetry of the structure, there exists a mathematical equivalence in the calculation of eccentric charges along the x and y directions. Therefore, the complete solution can be obtained through unidirectional analysis: (11)

[0070] In the formula, This represents the area of ​​a single induction electrode.

[0071] Calculate voltage value

[0072] Based on the structural design and parameters, the capacitance value when concentric is obtained:

[0073] (12)

[0074] According to the basic formula for capacitor voltage: U=Q / C, by combining equations (4)-(5) and (8)-(12), we can obtain:

[0075] (13)

[0076] In the formula: .

[0077] then, The differential voltage values ​​of the electrodes in the positive and negative directions of the z-axis are collected. At this time, the rotor is biased in the positive direction of the z-axis and needs to be adjusted in the negative direction of the z-axis. The specific offset is related to k.

[0078] After assembly, when it is necessary to adjust the displacement of the rotor base or stator base, the corresponding drive motor or lifting motor is started according to the coordinate direction to be adjusted, so as to drive the sliding platform to move or the adjusting rod to rise and fall, thereby realizing the displacement adjustment.

[0079] The differential voltage signal obtained according to the method of the present invention determines the eccentric displacement. The host computer program can send instructions in real time for adjustment, and drive the platform to realize the independent movement of a single motion axis or the coordinated movement of multiple motion axes in the X, Y and Z axes, thereby adjusting the relative spatial position between the rotor base 2 and the stator base 1 connected thereto.

[0080] Specifically, the aforementioned concentricity detection and adjustment methods can also be applied to scenarios including the alignment of stator and rotor assembly in aero-engines, dynamic adjustment of high-speed motor rotors, and real-time monitoring of axial or radial clearance in magnetic levitation bearing systems. They are also suitable for laboratory-level calibration of precision mechanical structures such as spherical sensors, spherical motors, and spherical hinges.

[0081] like Figure 5 , Figure 7 As shown, induction electrodes A, B, C, D, E, and F generate six induced signals U through electric field coupling. A U B U C U D U E U F The differential voltage signal along the X-axis is obtained by subtracting the UB and UD induced signals. Ux; will U A U C The difference between the induced signals is obtained by subtracting the difference from the input signals to obtain the differential voltage signal along the Y-axis. Uy; will UE U F The induced signal is subtracted by a subtractor to obtain the differential voltage signal along the Z-axis. Uz. According to Ux, Uy、 The magnitude and polarity of Uz are determined by the relative displacement deviation of the origin of the current sensor rotor base 2 relative to the origin of the stator base 1 in the X, Y, and Z directions, respectively. This deviation directly characterizes the radial mounting concentricity error of the sensor in this direction.

[0082] In S1, the amplitude Am of the low-frequency sinusoidal excitation signal is 12V, the frequency f is 40kHz, and the angular frequency ω = 2πf = 8 * 10⁻⁶. 4 *πrad / srad / s. Thus, using the above frequency and amplitude can meet the signal acquisition conditions and requirements of the sensing unit.

[0083] Example 2

[0084] like Figure 8 As shown, the concentricity measurement and detection principle structure and most of the structure of the spherical multidimensional rotational angular displacement sensor in this embodiment are the same as those in Embodiment 1. The only difference is the shape of each sensing electrode. In this embodiment, the sensing electrode is a spherical quadrilateral with a hollow center, and the hollow part is also a spherical quadrilateral.

[0085] Example 3

[0086] like Figure 9 As shown, the concentricity measurement and detection principle structure and most of the structure of the spherical multidimensional rotational angular displacement sensor in this embodiment are the same as those in Embodiment 1. The only difference is the shape of each sensing electrode; in this embodiment, the sensing electrode is a spherical ring.

[0087] Example 4

[0088] like Figure 10 As shown, the concentricity measurement and detection principle and most of the structure of the spherical multidimensional rotational angular displacement sensor in this embodiment are the same as those in Embodiment 1. The only difference is the shape and number of each sensing electrode. In this embodiment, the sensing electrodes are spherical rectangles, and there are 12 sensing electrodes, including sensing electrodes A, B, C, D, E, F, G, H, I, J, and K. Each sensing electrode is spherical rectangle, and each sensing unit has four sensing electrodes, which are symmetrically distributed in pairs. When acquiring the differential electrode signal of the sensing electrodes, the differential electrode signal of the four sensing electrodes in the same axial direction is acquired. Each stator base 1 has four sensing electrodes in the same coordinate direction. The more sensing electrodes there are, the more spatial information is acquired, and the more accurate the concentricity detection result of the rotor base 2 installation is.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the technical solutions. Those skilled in the art should understand that any modifications or equivalent substitutions to the technical solutions of the present invention without departing from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A spherical multi-dimensional rotary angle displacement sensor comprising a stator base and a rotor base, the stator base being in the shape of a spherical shell, the rotor base being in the shape of a sphere and located within the stator base spherical shell, a gap being present between the outer surface of the rotor base and the inner surface of the stator base such that the rotor base is suspended and concentric with the stator base; characterized in that, The excitation unit is a spherical shell-shaped excitation electrode covering the outer surface of the rotor base; the stator base inner surface is provided with three groups of induction units symmetrically arranged in three directions of the stator base three-dimensional coordinate system, each group of induction units comprises at least one pair of induction electrodes, each induction electrode has the same shape and size, and the center of each induction electrode is equidistant from the stator base spherical center.

2. The spherical multi-dimensional rotation angle displacement sensor according to claim 1, characterized by The excitation electrode is a metal electrode piece made of conductive material, which is tightly attached to the outer surface of the rotor base, and the inner diameter is equal to the outer diameter of the rotor base.

3. The spherical multi-dimensional rotation angle displacement sensor according to claim 1 or 2, characterized by The induction electrode is tightly attached to the inner surface of the stator base, and is a spherical quadrilateral, spherical circle or spherical circular ring with a central hollow part, which can be circular, triangular or polygonal.

4. The spherical multi-dimensional rotation angle displacement sensor according to claim 3, characterized by The inductive electrodes are provided with 6, each inductive electrode occupies the angle size .

5. The spherical multi-dimensional rotation angle displacement sensor according to claim 3, characterized by The induction electrode is provided with 12 induction electrodes, each induction electrode is a spherical rectangle, and each group of induction electrodes is provided with four induction electrodes.

6. A method for detecting and adjusting the concentricity of a base body of a spherical multidimensional rotary angle displacement sensor, characterized in that The concentricity detection and adjustment method is used for detecting and adjusting the concentricity of the stator base and the rotor base of the spherical multi-dimensional rotary angle displacement sensor, and comprises the following steps: S1, a preset characteristic sine electric excitation signal is applied to the excitation electrode arranged on the rotor base, an electric field is formed between the stator base and the rotor base, and a plurality of coupling capacitances are formed between the excitation electrode on the upper surface of the rotor base and the induction electrode on the inner surface of the stator base; S2, taking the coordinate axis direction of one group of induction electrodes as the first measurement direction, the differential voltage signals generated by one or two pairs of symmetrically distributed induction electrodes in the corresponding group of induction units in the coordinate direction are collected; S3, according to the amplitude and polarity of the differential voltage of the induction electrode obtained in S2, the relative displacement deviation amount and radial deviation direction of the spherical center of the rotor base relative to the spherical center of the stator base in the corresponding coordinate direction, or the relative displacement deviation amount and radial deviation direction of the spherical center of the stator base relative to the spherical center of the rotor base are judged; S4, according to the relative displacement deviation amount of the rotor base or the stator base in the coordinate direction in S3, the displacement of the rotor base or the stator base in the corresponding direction is adjusted; S5, taking the direction orthogonal to the first measurement direction as the second measurement direction, and taking the direction orthogonal to the second measurement direction as the third measurement direction, repeating the detection, judgment and adjustment process of S1-S4; S6, repeating the detection, judgment and adjustment process of S1-S5 until the differential voltage signals in the three coordinate directions independently reach and stabilize in the respective preset zero value threshold range, then it is determined that the theoretical rotary center point of the rotor base has been highly overlapped with the preset geometric center point of the stator base in the three-dimensional space.

7. The method for detecting and adjusting the concentricity of the base of the spherical multi-dimensional rotation angle displacement sensor according to claim 6, characterized in that, In S1, the amplitude Am of the low-frequency sine excitation signal is 10-14V, and the frequency f is 10-50kHz.

8. The method for detecting and adjusting the concentricity of the base of the spherical multi-dimensional rotation angle displacement sensor according to claim 6 or 7, characterized in that, Before detection, spherical multi-dimensional rotary angle displacement sensor is assembled on a detection table, the detection table is L-shaped or inverted T-shaped, and is composed of a horizontal plate and a vertical plate; a base positioning mechanism and a base adjusting mechanism are respectively arranged on the vertical plate and the horizontal plate, the base positioning mechanism comprises a positioning rod with one end fixedly connected with the vertical plate and the other end fixedly connected with an outer end surface of a rotor base or a stator base, the base adjusting mechanism comprises a sliding platform, a lifting motor and an adjusting rod, after two sides of the sliding platform are connected with two linear driving motors, left and right movement and front and back movement are realized, the lifting motor is fixedly installed on the sliding platform, the lifting motor is a linear motor, and the lower end of the adjusting rod is fixedly connected with the tail end of a push rod of the lifting motor, and the upper end is fixedly connected with the stator base or the rotor base; when displacement adjustment of the rotor base or the stator base is needed, according to the coordinate direction needed to be adjusted, the corresponding driving motor or the lifting motor is started, the sliding platform is moved or the adjusting rod is lifted, and displacement adjustment is realized.

9. The method for detecting and adjusting the concentricity of the base of the spherical multi-dimensional rotation angle displacement sensor according to claim 8, characterized in that, First and second guide grooves for guiding the sliding platform are further arranged on the horizontal plate, and the first and second guide grooves are vertically arranged.

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