A spherical multi-dimensional rotation angle measurement time grating sensor and its installation structure

Abstract

The present invention discloses a spherical multi-dimensional rotation angle measurement time-grating sensor and its installation structure. The time-grating sensor includes a stator base and a rotor base. The stator base is in the shape of a spherical shell, and the rotor base is in the shape of a spherical shell and is located within the stator base spherical shell. A gap is left between the surface of the rotor base and the inner surface of the stator base so that the rotor base is suspended and concentric with the stator base. Six excitation units of identical shape and size are evenly distributed on the inner surface of the stator base. The centers of the six excitation units are located at the centers of the six faces of a cube tangent to the inner surface of the stator base. Eight sensing units of identical shape and size are evenly distributed on the surface of the rotor base. The eight sensing units are symmetrically distributed in the eight quadrants of a spatial rectangular coordinate system with the center of the rotor base as the origin. The present invention can achieve high-precision multi-dimensional rotation angle measurement in spherical space, and has a simple structure, complete decoupling, and strong anti-interference ability.

Description

Technical Field

[0001] The present invention relates to a time-grating sensing technology, in particular to a spherical multi-dimensional rotation angle measurement time-grating sensor and a mounting structure thereof, and belongs to the field of precision angular displacement measurement. Background Art

[0002] Currently, the level of multi-dimensional, multi-parameter measurement technology has become a crucial factor in measuring the international competitiveness of my country's manufacturing industry, and its importance will become increasingly prominent in the new round of global high-end manufacturing competition. The current practice of simply combining multiple independent sensors to measure parameters is no longer able to meet the emerging demands of intelligent manufacturing. A single sensor unit capable of multi-dimensional, multi-parameter measurement has become a growing trend in precision testing technology. Spatial multi-dimensional rotational angular displacement measurement involves rotating about a constant center in multiple degrees of freedom. When using a ball joint as a carrier, this can be transformed into measuring the multi-degree-of-freedom rotation of a spherical rotor around its center within a constrained socket. For traditional industrial robot joints, if high-precision measurement of the spatial rotation angle of a ball joint can be achieved, the ball joint can be used to replace traditional single-degree-of-freedom rotational joints, effectively reducing the number of joints, simplifying the system architecture, and improving tracking accuracy and dynamic performance. However, conventional measuring instruments and equipment cannot achieve high-precision measurement of the multi-dimensional rotation angle of a ball joint, especially in applications with limited structural dimensions.

[0003] In recent years, a type of angular displacement time-grating sensor (publication number CN102425987B) has been developed in China that uses clock pulses as a displacement measurement reference. This sensor uses a high-frequency clock pulse as a measurement reference and employs an alternating electric field created by a flat-plate capacitor to directly couple the electrical traveling wave signal required for measurement. The high-frequency clock pulse is then used to perform phase interpolation processing on the induced signal to obtain the angular displacement value, enabling high-precision angular displacement measurement. However, current electric-field angular displacement time-grating sensors can only measure angular displacement in a single dimension and are unable to achieve multi-dimensional angular displacement measurement in spherical space. Summary of the Invention

[0004] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a spherical multi-dimensional rotation angle measurement time grating sensor and its installation structure. The present invention can achieve high-precision spherical space multi-dimensional rotation angle measurement, and has a simple structure, complete decoupling, and strong anti-interference ability.

[0005] The technical solution of the present invention is achieved as follows:

[0006] A spherical multi-dimensional rotation angle measurement time-grid sensor comprises a stator base and a rotor base, wherein an excitation unit is provided on the stator base, and a sensing unit is provided on the rotor base. The stator base is spherical, and the rotor base is spherical and located within the stator base spherical shell. A gap is left between the surface of the rotor base and the inner surface of the stator base, so that the rotor base is suspended and concentric with the stator base. The excitation units are six in shape and size and are evenly spaced on the inner surface of the stator base. The centers of the six excitation units are located at the centers of the six faces of a cube circumscribed to the inner surface of the stator base.

[0007] There are eight sensing units with exactly the same shape and size and evenly spaced apart on the surface of the rotor base; the eight sensing units are symmetrically distributed on eight quadrants of a spatial rectangular coordinate system with the center of the rotor base as the origin.

[0008] Furthermore, each excitation unit is composed of a metal pole piece made of a conductive material. The six metal pole pieces corresponding to the six excitation units are tightly attached to the inner surface of the stator matrix. The outer surface radius of each excitation unit is equal to the inner surface radius of the stator matrix.

[0009] Each sensing unit is composed of a metal pole piece made of conductive material. The eight metal pole pieces corresponding to the eight sensing units are tightly attached to the outer surface of the rotor base. The inner surface radius of each sensing unit is equal to the outer surface radius of the rotor base.

[0010] Furthermore, the angle occupied by each excitation unit is θ S The angle between two adjacent excitation units is δ S =π / 2-θ S ;

[0011] The angle occupied by each sensing unit is θ R , the angle between two adjacent sensing units is δ R =π / 2-θ R .

[0012] Furthermore, the center of the rotor base is hollowed out, and the hollowed part is spherical.

[0013] Furthermore, the outer contour of the excitation unit is a spherical quadrilateral or a spherical circle, a spherical quadrilateral with a hollow center, or a spherical circle with a hollow center; the outer contour of the sensing unit is a spherical triangle or a spherical circle, a spherical triangle with a hollow center, or a spherical circle.

[0014] Furthermore, the centers of all the excitation units are hollowed out; a mounting hole that penetrates inside and outside is provided on the stator base, and the mounting hole is opposite to the hollow part of one of the excitation units, so that the surface of the rotor base is connected to the outside through the mounting hole and the corresponding hollow part.

[0015] The present invention also provides a spherical multi-dimensional rotation angle measurement time grating sensor installation structure, the spherical multi-dimensional rotation angle measurement time grating sensor is the aforementioned spherical multi-dimensional rotation angle measurement time grating sensor, the stator base is rotatably connected to the stator drive turntable via a stator support shaft, the excitation electrode is connected to an external excitation source via a signal line passing through the stator base shell; the rotor base is rotatably connected to the rotor drive turntable via a rotor support shaft and the rotor base is suspended in the stator base; the signal line of the induction electrode is led out from the stator base through the rotor support shaft; the rotor support shaft and the stator support shaft are perpendicular to each other.

[0016] Furthermore, one end of the rotor support shaft is integrally formed with the surface of the rotor base and avoids the area where the induction unit is located, and the other end of the rotor support shaft passes through the mounting hole on the surface of the stator base and the hollow part corresponding to the mounting hole and is connected to the rotor drive turntable.

[0017] Furthermore, all the induction units are hollowed out in the center, and one end of the rotor support shaft is formed integrally with the surface of the rotor base through the hollow area of ​​one of the induction units, thereby avoiding the area where the induction unit is located.

[0018] Furthermore, one end of the stator support shaft is integrally formed with the outer surface of the stator base, and the other end of the stator support shaft is connected to the stator drive turntable; there is a rotation gap between the rotor support shaft and the mounting hole on the surface of the stator base and the hollow part corresponding to the mounting hole, and the rotation angle of the stator support shaft is limited by the rotation gap.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention uses a staggered arrangement of six excitation units to achieve simultaneous encoding in the X and Z orthogonal directions in spherical space. The sensing units are arranged in a pairwise differential structure to pick up signals. An adder is used to sum the output signals of two adjacent sensing units to filter out coupled signals in non-measurement directions. A subtractor is used to subtract the differential signals to eliminate common-mode interference, thereby further improving the signal decoupling capability, achieving thorough decoupling and strong anti-interference capability, and realizing high-precision spherical multi-dimensional rotational angular displacement measurement. The structure is simple and easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a diagram showing the relative relationship between the stator base and the rotor base in Example 1.

[0022] Figure 2 Schematic diagram of the stator matrix structure in Example 1.

[0023] Figure 3 Schematic diagram of the rotor base structure in Example 1.

[0024] Figure 4 Schematic diagram of angular displacement solution in Example 1.

[0025] Figure 5 Schematic diagram of the relative position relationship of the stator base excitation unit in Example 1.

[0026] Figure 6 This is a schematic diagram of signal processing in Example 1.

[0027] Figure 7 Schematic diagram of the shape of the stator base excitation unit in Example 2.

[0028] Figure 8 Schematic diagram of the shape of the stator matrix excitation unit in Example 3.

[0029] Figure 9 Schematic diagram of the shape of the stator base excitation unit in Example 4.

[0030] Figure 10 This is a schematic diagram of the shape of the rotor base induction unit in Example 5.

[0031] Figure 11 This is a schematic diagram of the shape of the rotor base induction unit in Example 6.

[0032] Figure 12 This is a schematic diagram of the shape of the rotor base induction unit in Example 7.

[0033] Figure 13 This is a schematic diagram of the installation structure of the grating sensor for measuring the spherical multi-dimensional rotation angle of the present invention. DETAILED DESCRIPTION

[0034] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] The present invention discloses a spherical multi-dimensional rotation angle measurement time-grating sensor, comprising a stator base and a rotor base. The stator base is provided with an excitation unit, and the rotor base is provided with a sensing unit. The stator base is spherical, and the rotor base is spherical and located within the stator base spherical shell. A gap is left 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.

[0036] The excitation units are 6 in shape and size, evenly spaced and not in contact with each other, and are respectively named A, B, C, D, E, and F. The centers of the 6 excitation units are located at the centers of the six faces of a cube tangent to the inner surface of the stator base. The 6 excitation units of the present invention are symmetrical with respect to the XOY plane, the XOZ plane, and the YOZ plane, that is, the 6 excitation units are respectively located on the coordinate axes X+, X-, Y+, Y-, Z+, and Z-, and the 6 excitation units are equidistant from the coordinate origin O. Among the 6 excitation units, it can be considered that 4 excitation units A, B, C, and D rotate around the Z axis, and 4 excitation units A, E, C, and F rotate around the X axis, among which excitation unit A and excitation unit C are excitation units shared by the rotation directions around the Z axis and around the X axis. Of course, because they are arranged symmetrically in the X, Y, and Z directions, other interpretations are also possible, such as four excitation units rotating in the Z-axis direction and four rotating in the Y-axis direction, where two excitation units are shared by the Z-axis and Y-axis directions; or four excitation units rotating in the X-axis direction and four rotating in the Y-axis direction, where two excitation units are shared by the X-axis and Y-axis directions.

[0037] The eight sensing units are identical in shape and size, evenly spaced and non-contacting on the surface of the rotor base. The eight sensing units are symmetrically distributed in the eight quadrants of a rectangular coordinate system with the center of the rotor base as the origin. The eight sensing units are equidistant from the coordinate origin and are spherically symmetrical about the center of the sphere. The eight sensing units are located within the sphere formed by the six excitation units, i.e., the outer radius of the sensing units is smaller than the inner radius of the excitation units.

[0038] Each excitation unit in the present invention is composed of a conductive metal pole piece. The six metal pole pieces corresponding to the six excitation units are tightly attached to the inner surface of the stator base, meaning the outer radius of the excitation unit is equal to the inner radius of the stator base. Similarly, each induction unit is composed of a conductive metal pole piece. The eight metal pole pieces corresponding to the eight induction units are tightly attached to the outer surface of the rotor base, meaning the inner radius of each induction unit is equal to the outer radius of the rotor base.

[0039] Set the outer surface radius of sub-substrate 1 to r S , the stator matrix thickness is d S , then the inner surface radius of the stator base is r' S =r S -d S The thickness of each excitation unit is d' S , then the inner surface radius of the excitation unit is r" S＝ r' S -d' S Assume that the angle occupied by each excitation unit is θ S, then the arc length of the excitation unit is w S =θ S ×r S / 2. Since the centers of two adjacent excitation units are 90° apart, the angle between the closest points of the two adjacent excitation units is δ S =π / 2-θ S ; Assume that the angle occupied by each sensing unit is θ R , then the angle between the closest two adjacent sensing units is δ R =π / 2-θ R .

[0040] The rotor base 2 is a standard sphere with a hollow center, and the hollow part is also a standard sphere. The radius of the hollow part, that is, the radius of the inner surface of the rotor base, is r" R , the rotor base thickness is d' R , then the radius of the outer surface of the rotor base is r' R =r” R +d' R The thickness of each sensing unit is d R , then the outer surface radius is r R =r' R +d R The arc length of each sensing unit is w R =θ R ×r R / 2.

[0041] The outer contour shape of the excitation unit is preferably a spherical quadrilateral or a spherical circle, or a spherical ring structure formed by a corresponding quadrilateral hole or circular hole in the center of the spherical quadrilateral or spherical circle; the outer contour shape of the sensing unit is a spherical triangle or a spherical circle, or a spherical ring structure formed by a circular hole in the center of the spherical triangle or spherical circle.

[0042] For the structure with a hollow setting in the center of the excitation unit (that is, a spherical ring structure formed by a corresponding quadrilateral hole or circular hole in the center), a mounting hole that passes through the inside and outside is provided on the stator base. The mounting hole is directly opposite to the hollow part of one of the excitation units, so that the surface of the rotor base is connected to the outside through the mounting hole and the corresponding hollow part, thereby facilitating the connection between the rotor and the external rotor drive turntable.

[0043] Example 1: Figures 1 to 6 As shown, in this embodiment, the spherical multi-dimensional rotation angle measurement time-grid displacement sensor based on the alternating electric field is used. The stator base 1 and the rotor base 2 are installed concentrically with a spacing of d=26 mm. The thickness of the stator base is d S =10mm, stator base inner radius r' S =76mm, the thickness of the excitation unit set on the inner surface of the stator base d' S=2mm. Rotor base thickness d' R =40mm, rotor base outer radius r' R =50mm, the thickness of the induction unit set on the outer surface of the rotor base is d R =2mm.

[0044] like Figure 2 and Figure 5 As shown, the inner surface of the stator base 1 is provided with 6 excitation units A, B, C, D, E, and F with the same shape and size. The angle occupied by a single excitation unit is θ S =π / 3, the gap between adjacent excitation units δ S =π / 2-θ S =π / 6, 6 excitation units are installed concentrically.

[0045] The six excitation units are arranged at equal spatial angles around the Z axis and the X axis respectively. The four excitation units arranged in the rotation direction of the Z axis are fed with different sinusoidal excitation signals, and the four excitation units arranged in the rotation direction of the X axis are fed with different sinusoidal excitation signals. The specific implementation method is as follows: the four excitation units A, B, C, and D arranged in the Z axis direction are fed with sinusoidal excitation signals Am*sin(ωt), Am*sin(ωt+π / 2), Am*sin(ωt+π), and Am*sin(ωt+3π / 2) respectively. The four excitation units A, E, C, and F arranged in the X axis direction are fed with four sinusoidal excitation signals Am*sin(ωt), Am*sin(ωt+π / 2), Am*sin(ωt+π), and Am*sin(ωt+3π / 2) respectively. The four excitation units arranged in the Z axis and the four excitation units arranged in the X axis share excitation unit A and excitation unit C. The four excitation units arranged around the Z axis are respectively fed with four sinusoidal excitation signals of equal amplitude and same frequency with a phase difference of 90°, forming an alternating electric field in space; the four excitation units arranged around the X axis are respectively fed with four sinusoidal excitation signals of equal amplitude and same frequency with a phase difference of 90°, forming an alternating electric field in space.

[0046] like Figure 3 As shown, the outer surface of the rotor base 2 is provided with 8 sensing units a, b, c, d, e, f, g, h of identical shape and size. The shape of a single sensing unit is a spherical triangle, and the angle occupied by a single sensing unit is θ R =5π / 12. The 8 sensing units are located in the 8 quadrants of the spatial rectangular coordinate system. The distance between the 8 sensing units and the coordinate origin is equal to the outer radius r' of the rotor base R =50mm, 8 sensing units are located on the same sphere and do not touch each other, and the gap between adjacent sensing units is δ R =π / 2-θ R =π / 12.

[0047] The 8 induction units on the upper surface of the rotor base 2 and the 6 excitation units on the inner surface of the stator base 1 form a coupling capacitor. During measurement, four sinusoidal excitation signals of the same frequency and amplitude with a phase difference of π / 2 are applied to the 6 excitation units in sequence. U A Phase sinusoidal excitation signal, U A =Am*sin(ωt), U is applied to the excitation units B and E B Phase sinusoidal excitation signal, U B =Am*sin(ωt+π / 2), U is applied to the excitation unit C C Phase sinusoidal excitation signal, U C =Am*sin(ωt+π), U is applied to the excitation units D and F D Phase sinusoidal excitation signal, U D =Am*sin(ωt+3π / 2). Wherein the excitation signal amplitude A=12V, frequency f=40kHz, angular frequency ω=2πf=8*10 4 πrad / s. When the rotor base 2 rotates relative to the stator base 1, the induction units a, b, c, d, e, f, g, and h generate eight sinusoidal induction signals of the same frequency and amplitude, Ua, Ub, Uc, Ud, Ue, Uf, Ug, and Uh, respectively, through electric field coupling.

[0048] Signal processing methods such as Figure 4 and Figure 6 As shown, Ua, Ud, Ue, Uh and Ub, Uc, Uf, and Ug are summed up through adders to obtain sinusoidal traveling wave signals Uz+ and Uz- containing only angular displacements around the Z axis; Ua, Ub, Uc, Ud and Ue, Uf, Ug, and Uh are summed up through adders to obtain angular displacement signals Ux+ and Ux- containing only angular displacements around the X axis. Uz+ and Uz- are subtracted through a subtractor to obtain a sinusoidal traveling wave signal Uz containing only angular displacements around the Z axis; Ux+ and Ux- are subtracted through a subtractor to obtain a sinusoidal traveling wave signal Ux containing only angular displacements around the X axis. The expressions for traveling wave signals Uz and Ux are as follows:

[0049]

[0050] The traveling wave signal Uz containing only the angular displacement around the Z axis and the traveling wave signal Ux containing only the angular displacement around the X axis are transformed into square waves by the shaping circuit and sent to the FPGA for phase detection processing at the same time. ref The phase difference is represented by the number of interpolated high-frequency clock pulses. After conversion, the rotational angular displacement α of the rotor base 2 relative to the stator base 1 in the Z-axis direction is obtained. z and the rotational angular displacement α around the X axis x .

[0051] Example 2: The spherical multi-dimensional rotation angle measurement time-grating displacement sensor based on alternating electric field in this embodiment has the same measurement principle and most of the structure as that of Example 1, except that: Figure 7 As shown, the shape of the excitation unit is a spherical quadrilateral.

[0052] Example 3: The spherical multi-dimensional rotation angle measurement time-grating displacement sensor based on alternating electric field in this embodiment has the same measurement principle and most of the structure as that of Example 1, except that: Figure 8 As shown, the shape of the excitation unit is a spherical quadrilateral with a hollow center, and the shape of the hollow part is a spherical quadrilateral.

[0053] Example 4: The spherical multi-dimensional rotation angle measurement time-grating displacement sensor based on alternating electric field in this embodiment has the same measurement principle and most of the structure as that of Example 3, except that: Figure 9 As shown, the shape of the excitation unit is a spherical quadrilateral with a hollow center, and the shape of the hollow part is a spherical circle. Each excitation unit is composed of four metal pole pieces, and the electric field formed is more uniform. That is, the metal pole pieces Wa1, Wa2, Wa3, and Wa4 are connected by excitation signal leads to form an excitation unit A; the metal pole pieces Wb1, Wb2, Wb3, and Wb4 are connected by excitation signal leads to form an excitation unit B; the metal pole pieces Wc1, Wc2, Wc3, and Wc4 are connected by excitation signal leads to form an excitation unit C; the metal pole pieces Wd1, Wd2, Wd3, and Wd4 are connected by excitation signal leads to form an excitation unit D; the metal pole pieces We1, We2, We3, and We4 are connected by excitation signal leads to form an excitation unit E; and the metal pole pieces Wf1, Wf2, Wf3, and Wf4 are connected by excitation signal leads to form an excitation unit F. In the same excitation unit, the gap between two adjacent metal pole pieces is δ' S =1°.

[0054] Example 5: The spherical multi-dimensional rotation angle measurement time-grating displacement sensor based on alternating electric field in this embodiment has the same measurement principle and most of the structure as that of Example 1, except that: Figure 10 As shown, each sensing unit consists of 6 metal pole pieces. Taking sensing unit a as an example, it consists of metal pole pieces a1, a2, a3, a4, a5, and a6. The 6 metal pole pieces of each sensing unit are connected together by wires. In the same sensing unit, the gap between two adjacent metal pole pieces is δ' R =1°.

[0055] Example 6: The spherical multi-dimensional rotation angle measurement time-grating displacement sensor based on alternating electric field in this embodiment has the same measurement principle and most of the structure as that of Example 1, except that: Figure 11As shown, each sensing unit is spherical and the angle occupied by each sensing unit is θ R =5π / 12.

[0056] Example 7: The spherical multi-dimensional rotation angle measurement time-grating displacement sensor based on alternating electric field in this embodiment has the same measurement principle and most of the structure as that of Example 1, except that: Figure 12 As shown, each sensing unit is shaped like a spherical triangle with a hollow center, and the hollowed portion is a spherical circle.

[0057] See also Figure 13 The present invention also provides a spherical multi-dimensional rotation angle measurement time-grating sensor mounting structure, wherein the center of all excitation units of the spherical multi-dimensional rotation angle measurement time-grating sensor is hollowed out. A circular mounting hole 3 is provided on the stator base 1, extending from the inside to the outside. This mounting hole is aligned with the hollowed-out portion of one of the excitation units, so that the surface of the rotor base communicates with the outside through the mounting hole and the corresponding hollowed-out portion. The stator base 1 is rotatably connected to the stator drive turntable via a stator support shaft 4, and the excitation electrode is connected to the external excitation source via a signal line that passes through the stator base housing. The rotor base 2 is rotatably connected to the rotor drive turntable via a rotor support shaft 5, and the rotor base is suspended within the stator base. The signal line of the sensing electrode is led out of the stator base via the rotor support shaft. The rotor support shaft 5 and the stator support shaft 4 are perpendicular to each other.

[0058] During actual installation, one end of the rotor support shaft is integrally formed with the surface of the rotor base and avoids the area where the induction unit is located. The other end of the rotor support shaft passes through the mounting hole on the surface of the stator base and the hollow part corresponding to the mounting hole and is connected to the rotor drive turntable.

[0059] To facilitate the rotor support shaft's avoidance of the sensing unit area, the centers of all sensing units are hollowed out in this embodiment of the present invention. One end of the rotor support shaft is integrally formed with the rotor base surface, passing through the hollowed-out area of ​​one of the sensing units, thus avoiding the sensing unit area. Of course, the rotor support shaft can also be connected to the rotor base in the gaps left between the four sensing units.

[0060] One end of the stator support shaft is integrally formed with the outer surface of the stator base, and the other end is connected to the stator drive turntable. While the rotor support shaft can rotate 360°, the stator support shaft cannot. A rotational clearance exists between the rotor support shaft and the mounting hole on the stator base surface and the corresponding hollow portion. The rotational angle of the stator support shaft is limited by this rotational clearance.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the applicant has described the present invention in detail with reference to the preferred embodiments, those skilled in the art should understand that modifications or equivalent replacements of the technical solutions of the present invention without departing from the purpose and scope of the technical solutions should be included in the scope of the claims of the present invention.

Claims

1. A spherical multi-dimensional rotation angle measurement time-grid sensor, comprising a stator base and a rotor base, wherein the stator base is provided with an excitation unit and the rotor base is provided with a sensing unit; characterized in that: The stator base is spherical, the rotor base is spherical and located within the stator base spherical shell, and a gap is left between the surface of the rotor base and the inner surface of the stator base so that the rotor base is suspended and concentric with the stator base. The six excitation units are identical in shape and size and are evenly spaced on the inner surface of the stator base. The centers of the six excitation units are located at the centers of the six faces of a cube circumscribed to the inner surface of the stator base. The eight sensing units are identical in shape and size and are evenly spaced on the surface of the rotor base; the eight sensing units are symmetrically distributed in the eight quadrants of a spatial rectangular coordinate system with the center of the rotor base as the origin; Each excitation unit is composed of a metal pole piece made of conductive material. The six metal pole pieces corresponding to the six excitation units are tightly fitted to the inner surface of the stator matrix. The outer surface radius of each excitation unit is equal to the inner surface radius of the stator matrix. Each sensing unit is composed of a conductive metal pole piece. The eight metal pole pieces corresponding to the eight sensing units are tightly attached to the outer surface of the rotor base. The inner surface radius of each sensing unit is equal to the outer surface radius of the rotor base. The angle occupied by each excitation unit is θ S , the angle between two adjacent excitation units is δ S = π / 2- θ S ; The angle occupied by each sensing unit is θ R , the angle between two adjacent sensing units is δ R =π / 2-θ R .

2. The spherical multi-dimensional rotation angle measurement time grating sensor according to claim 1, characterized in that: The center of the rotor base is hollowed out, and the hollowed-out part is spherical.

3. The spherical multi-dimensional rotation angle measurement time grating sensor according to claim 1, characterized in that: The outer contour of the excitation unit is a spherical quadrilateral or a spherical circle, a spherical quadrilateral with a hollow center, or a spherical circle with a hollow center; the outer contour of the sensing unit is a spherical triangle or a spherical circle, a spherical triangle with a hollow center, or a spherical circle.

4. The spherical multi-dimensional rotation angle measurement time grating sensor according to claim 1, characterized in that: The centers of all the excitation units are hollowed out; a mounting hole that penetrates inside and outside is provided on the stator base, and the mounting hole is directly opposite to the hollow part of one of the excitation units, so that the surface of the rotor base is connected to the outside through the mounting hole and the corresponding hollow part.

5. A spherical multi-dimensional rotation angle measurement time grid sensor installation structure, characterized by: The spherical multi-dimensional rotation angle measurement time-grating sensor is the spherical multi-dimensional rotation angle measurement time-grating sensor according to claim 4, wherein the stator base is rotatably connected to the stator drive turntable through a stator support shaft, and the metal pole piece of the excitation unit is connected to the external excitation source through a signal line passing through the stator base shell; the rotor base is rotatably connected to the rotor drive turntable through the rotor support shaft and the rotor base is suspended in the stator base; the signal line of the metal pole piece of the sensing unit is led out from the stator base through the rotor support shaft; the rotor support shaft and the stator support shaft are perpendicular to each other.

6. The spherical multi-dimensional rotation angle measurement time grating sensor installation structure according to claim 5, characterized in that: One end of the rotor support shaft is integrally formed with the surface of the rotor base and avoids the area where the induction unit is located. The other end of the rotor support shaft passes through the mounting hole on the surface of the stator base and the hollow part corresponding to the mounting hole and is connected to the rotor drive turntable.

7. The spherical multi-dimensional rotation angle measurement time grating sensor installation structure according to claim 6, characterized in that: All the induction units are hollowed out in the center, and one end of the rotor support shaft is formed integrally with the surface of the rotor base through the hollow area of ​​one of the induction units, thereby avoiding the area where the induction unit is located.

8. The spherical multi-dimensional rotation angle measurement time grating sensor installation structure according to claim 6 or 7, characterized in that: One end of the stator support shaft is integrally formed with the outer surface of the stator base, and the other end of the stator support shaft is connected to the stator drive turntable; There is a rotation gap between the rotor support shaft and the mounting hole on the surface of the stator base body and the hollow portion corresponding to the mounting hole. The rotation angle of the stator support shaft is limited by the rotation gap.

Images