Absolute displacement sensor for combined measurement of angular displacement and linear displacement by means of magnetic field

Abstract

The application discloses a kind of absolute displacement sensors of magnetic field type angular displacement and linear displacement compound measurement, including stator and rotor, rotor coaxial sleeve is set in stator outside and has gap, stator includes stator matrix and is arranged on the outer cylindrical surface of stator matrix excitation unit, rotor includes rotor matrix and is arranged on the inner cylindrical surface of rotor matrix induction unit.When rotor moves relative to stator, angular displacement and linear displacement induction signal pickup array output traveling wave signal, and, and, processing and resolving to traveling wave signal, obtain the absolute angular displacement of circumferential and the absolute linear displacement of axial.The application has the advantages of simple structure, absolute positioning, easy batch manufacturing, low cost and the like.

Description

Technical Field

[0001] This invention belongs to the field of precision angular displacement measurement sensor technology, specifically relating to an absolute displacement sensor that combines magnetic field-type angular displacement and linear displacement measurement. Background Technology

[0002] With the ongoing upgrading and transformation of industrial manufacturing worldwide, traditional single-function sensors are no longer sufficient to meet increasingly complex measurement needs, making the market demand for multifunctional integrated measurement sensors increasingly urgent. For example, in equipment such as CNC positioning stages, microscope stages, and robotic arms, high-precision angular and linear displacement information is often required simultaneously when performing position adjustments. Traditional measurement methods typically use two independent systems: a linear displacement sensor and an angular displacement sensor. However, this approach suffers from several problems: complex system structure, high cost, weak anti-interference capability, susceptibility to environmental influences, introduction of Abbe and multi-axis cumulative errors, and difficulty in deploying two sensors in scenarios with limited installation space. Therefore, the development of a displacement sensor that combines multifunctionality, high precision, and a compact structure is urgently needed.

[0003] In recent years, a time-grating linear displacement sensor using clock pulses as the displacement measurement reference has been developed domestically, effectively improving the accuracy and resolution of displacement measurements. Currently, angular and linear displacement sensor technologies based on the time-grating principle are maturing, and related products are gradually entering the market. However, sensors capable of simultaneously measuring absolute angular and absolute linear displacement remain a research gap. Therefore, there is an urgent need to develop a new type of sensor with a simple structure, high accuracy, and the ability to simultaneously measure absolute angular and linear displacement. Summary of the Invention

[0004] The purpose of this invention is to provide an absolute displacement sensor that combines magnetic field-based angular and linear displacement measurement, so as to achieve high-precision measurement of absolute angular and linear displacement, while simplifying the structure and providing a long-term stable and reliable position reference for CNC equipment.

[0005] The absolute displacement sensor for combined measurement of magnetic field angular displacement and linear displacement of the present invention includes a stator and a mover. The mover is coaxially sleeved outside the stator with a gap. The stator includes a stator base and an excitation unit disposed on the outer cylindrical surface of the stator base. The mover includes a mover base and a sensing unit disposed on the inner cylindrical surface of the mover base.

[0006] The excitation unit includes an axial coarse measurement excitation coil array, a circumferential coarse measurement excitation coil array, an axial fine measurement excitation coil array, and a circumferential fine measurement excitation coil array, all located on different layers and insulated from each other. The induction unit includes a first induction coil, a second induction coil, a third induction coil, and a fourth induction coil; the first induction coil is directly coupled to the axial coarse measurement excitation coil array, the second induction coil is directly coupled to the circumferential coarse measurement excitation coil array, the third induction coil is directly coupled to the axial fine measurement excitation coil array, and the fourth induction coil is directly coupled to the circumferential fine measurement excitation coil array.

[0007] When the moving part moves linearly and / or rotates relative to the stator, an excitation signal is first applied to the axial coarse excitation coil array and / or the circumferential coarse excitation coil array, the remaining excitation coil array is grounded, and the first induction coil and / or the second induction coil outputs a traveling wave signal. and / or And store; then, quickly switch the excitation signal to the axial precision measurement excitation coil array and / or the circumferential precision measurement excitation coil array, ground the remaining excitation coil array, and output traveling wave signals from the third induction coil and / or the fourth induction coil. and / or For traveling wave signals and / or After processing, the coarse linear displacement is obtained. and / or coarse angular displacement For traveling wave signals and / or The process is performed to obtain the precise linear displacement. and / or precise measurement of angular displacement ,right , and / or , Perform absolute displacement calculations to obtain the absolute linear displacement values. and / or absolute angular displacement value .

[0008] The excitation unit is layered with four independent coil arrays for axial coarse measurement, circumferential coarse measurement, axial fine measurement, and circumferential fine measurement. Each layer of coils is mutually insulated, achieving complete electrical decoupling between the coarse and fine measurement channels. This avoids interference between coarse and fine measurement signals, preventing measurement distortion and improving signal purity. The mover side is equipped with four independent induction coils magnetically coupled to four excitation arrays, one-to-one. The physical paths of the axial, circumferential, coarse, and fine measurement channels are independently distinguished, allowing for the acquisition of linear or angular displacement signals individually or simultaneously. This adapts to various working mechanisms, including single linear motion, single rotational motion, and linear + rotational composite linkage. The coarse measurement excitation coil array is first excited and the traveling wave signal is stored. Then, the system quickly switches to the fine measurement excitation coil array to acquire the traveling wave signal for fine measurement. All other non-working excitation coil arrays are uniformly grounded and shielded. This time-division acquisition avoids magnetic field superposition interference caused by multi-channel synchronous excitation, and the grounding further absorbs stray electromagnetic signals, reducing measurement noise.

[0009] The axial coarse measurement excitation coil array consists of 4M1 identical first coils evenly spaced along the axial direction. The arrangement consists of a first coil that, when unfolded circumferentially, forms a rectangle. The central angle subtended by the length of the first coil is... Width is ;No. The first coil is wound forward, the second... The first coil is reverse-wound, and the second... The first coil and the first The first coils connected in series form the first excitation group for axial coarse measurement; the first... The first coil is wound forward, the second... The first coil is reverse-wound, and the second... The first coil and the first The first coils are connected in series to form the second excitation group for axial coarse measurement; among them... Take all integers from 0 to M1-1 in sequence. M1 represents the gap angle between the two short sides of the first coil, and M1 represents the number of pole pairs of the axial coarse excitation coil array.

[0010] The circumferential coarse measurement excitation coil array consists of 4M2 identical second coils evenly spaced circumferentially. The arrangement consists of a second coil that unfolds into a rectangle along its circumference. The length of the second coil is L1, and the central angle subtended by its width is... ;No. The second coil is wound forward, the first... The second coil is reverse-wound, and the first... The second coil and the first The second coils connected in series form the first excitation group for circumferential coarse measurement; the... The second coil is wound forward, the first... The second coil is reverse-wound, and the first... The second coil and the first The second coils are connected in series to form the second excitation group for circumferential coarse measurement; among them... Take all integers from 0 to M2-1 in sequence. M2 represents the number of pole pairs of the circumferential coarse excitation coil array.

[0011] The axial precision excitation coil array and the axial coarse excitation coil array have the same starting position in the axial direction.

[0012] The axial precision excitation coil array consists of 4N1 identical third coils evenly spaced along the axial direction. The arrangement is such that the third coil, when unfolded circumferentially, forms a rectangle, and the central angle subtended by the length of the third coil is... Width is ;4th +1 third coil is wound forward, 4th... +3 third coils reverse-wound, and the first The third coil and the first The third coil connected in series forms the first excitation group for axial precision measurement; the fourth... +2 third coils are wound forward, the 4th... +4 third coils reverse-wound, and the first The third coil and the first A third coil connected in series constitutes the second excitation group for axial precision measurement; among which... Take all integers from 0 to N1-1 in sequence. The gap angle between the two short sides of the third coil is represented by N1, which represents the number of pole pairs in the axial precision excitation coil array. N1 and M1 are coprime. .

[0013] The circumferential precision excitation coil array and the circumferential coarse excitation coil array have the same starting position.

[0014] The circumferential precision excitation coil array consists of 4N2 identical fourth coils evenly spaced circumferentially. The arrangement consists of four coils. The fourth coil, when unfolded circumferentially, forms a rectangle. The length of the fourth coil is L2, and the central angle subtended by its width is... ;No. The fourth coil is wound, the... The fourth coil is reverse-wound, and the... The fourth coil and the first The fourth coil connected in series constitutes the first excitation group for circumferential precision measurement; the... The fourth coil is wound, the... The fourth coil is reverse-wound, and the... The fourth coil and the first The fourth coil is connected in series to form the second excitation group for circumferential precision measurement; among them... Take all integers from 0 to N²-1 in sequence. N2 represents the number of pole pairs of the circumferential precision excitation coil array, and N2 and M2 are coprime.

[0015] Both the coarse and fine measurement excitation coil arrays employ a winding structure of four coils per group, with paired and connected in opposite directions. Within each group, the magnetic fields of the positive and negative coils cancel each other out common-mode interference, significantly suppressing noise from external stray magnetic fields and leakage magnetic fields at the coil ends, resulting in a higher sinusoidal output traveling wave signal. The axial starting positions of the coarse and fine measurement excitation coil arrays are aligned, as are the circumferential starting positions of the coarse and fine measurement excitation coil arrays. This unifies the spatial phase reference of the coarse and fine measurement signals, eliminating the need for additional phase compensation in subsequent coarse and fine displacement fusion calculations and reducing the complexity of the back-end algorithm.

[0016] The first induction coil consists of two axially coarse-measured first and second axially coarse-measured conductor segments that, when unfolded circumferentially, exhibit a sinusoidal waveform. The starting ends of the axially coarse-measured first and second axially coarse-measured conductor segments are connected via vias, and their ending ends serve as traveling wave signals. At the output end, the winding curve of the first conductor segment is roughly measured axially. The axial rough measurement of the winding curve of the second conductor segment is as follows: ;in, , , Indicates the winding curve The radius of curvature, Indicates the winding curve The radius of curvature, This indicates the pole pitch of the axial coarse measurement excitation coil array. The axial height of the first induction coil is... Its width is exactly equal to the total width occupied by the four first coils arranged sequentially along the axial direction, which can avoid introducing unnecessary high-order harmonic errors into the induction signal obtained from the axial coarse measurement channel, making the decoupling of the axial coarse measurement induction signal purer. The first induction coil is formed by combining a pair of symmetrical sinusoidal wire segments. The Z-axis coordinate of the two wire segments synchronously follows the linear extension of the axial coarse measurement excitation coil array, completely matching the axial period of the axial coarse measurement excitation coil array, and can achieve full-domain synchronous magnetic coupling with the axial coarse measurement excitation magnetic field, ensuring the stability of the induction signal amplitude throughout the entire stroke. The X and Y coordinates of the two wire segments are symmetrically distributed with positive and negative sinusoids. The common-mode stray interference magnetic fields induced by the two cancel each other out, effectively suppressing the noise caused by stator end leakage magnetic field and external power frequency magnetic field, and improving the output traveling wave signal. The sine fidelity.

[0017] The second induction coil consists of two circumferential coarse-measurement first and second circumferential coarse-measurement conductor segments that, when unfolded circumferentially, form a sinusoidal waveform. The starting ends of the first and second circumferential coarse-measurement conductor segments are connected by vias, and their ending ends serve as traveling wave signals. At the output end, the winding curve of the first conductor segment is roughly measured in the circumferential direction. The circumferential rough measurement of the winding curve of the second conductor segment (222) is as follows: ;in, , , Indicates the winding curve The radius of curvature, Indicates the winding curve The radius of curvature, This represents the central angle subtended by the pole pitch of the circumferential coarse measurement excitation coil array. , This indicates the amplitude of the first conductor segment measured roughly in the circumferential direction. The angle of the second induction coil along the circumferential direction is... This coincides with an integer cycle of the circumferential coarse measurement excitation coil array, thereby enhancing the amplitude of the induced signal obtained from the circumferential coarse measurement channel and improving the decoupling signal-to-noise ratio of the circumferential coarse measurement induced signal. The second induction coil is composed of two sinusoidally symmetrical conductor segments paired together. The amplitudes of their Z-axis sine curves are equal, but their phases are opposite. The induced voltages generated by external stray magnetic fields and coil common-mode interference can cancel each other out, effectively suppressing measurement noise and improving the output traveling wave signal. The waveform purity is high. The circumferential sinusoidal distribution conductor can completely cover the periodic changes of the circumferential coarse measurement excitation magnetic field. The moving part can stably couple and modulate the magnetic field throughout the entire rotation of the moving part, outputting a traveling wave signal with excellent sinusoidal properties, ensuring the linearity of the angular displacement coarse measurement solution and the stability of the position recognition.

[0018] The third induction coil consists of two axial precision measurement first and second conductor segments that unfold circumferentially to form a sinusoidal waveform. The starting ends of the axial precision measurement first and second conductor segments are connected by vias, and their ending ends serve as traveling wave signals. At the output end, the winding curve of the first conductor segment is accurately measured axially. The winding curve of the second conductor segment was measured axially. ;in, , , winding curve The radius of curvature is also and winding curve The radius of curvature is also , This indicates the pole pitch of the axial precision excitation coil array. The axial height of the third induction coil is... Its width is exactly equal to the total width occupied by the four third coils arranged sequentially along the axial direction, which avoids introducing unnecessary high-order harmonic errors into the induction signal obtained from the axial precision measurement channel, making the decoupling of the induction signal in the axial direction precision measurement purer. The third induction coil is formed by combining a pair of symmetrical sinusoidal wire segments. The Z-axis coordinate of the two wire segments synchronously follows the linear extension of the axial precision measurement excitation coil array, completely matching the axial period of the axial precision measurement excitation coil array. It can achieve full-domain synchronous magnetic coupling with the axial precision measurement excitation magnetic field, ensuring the stability of the induction signal amplitude throughout the entire stroke. The X and Y coordinates of the two wire segments are symmetrically distributed with positive and negative sinusoids. The common-mode stray interference magnetic fields induced by the two cancel each other out, effectively suppressing the noise caused by stator end leakage magnetic field and external power frequency magnetic field, and improving the output traveling wave signal. The sine fidelity.

[0019] The fourth induction coil consists of two circumferentially measured first and second circumferentially measured conductor segments that unfold into a sinusoidal waveform. The starting ends of the circumferentially measured first and second circumferentially measured conductor segments are connected by vias, and their ending ends serve as traveling wave signals. At the output end, the winding curve of the first conductor segment is determined by circumferential precision measurement. The winding curve of the second conductor segment, measured circumferentially, is as follows: ;in, , , winding curve The radius of curvature is also , winding curve The radius of curvature is also , This indicates the amplitude of the first traverse segment measured circumferentially. This represents the central angle subtended by the pole pitch of the circumferential precision measuring excitation coil array. , The angle of the four induction coils along the circumference is... This coincides with an integer cycle of the circumferential precision measurement excitation coil array, thereby enhancing the amplitude of the induced signal obtained from the circumferential precision measurement channel and improving the decoupling signal-to-noise ratio of the circumferential precision measurement induced signal. The fourth induction coil is composed of two sinusoidally symmetrical conductor segments paired together. The amplitudes of their Z-axis sine curves are equal, but their phases are opposite. The induced voltages generated by external stray magnetic fields and coil common-mode interference can cancel each other out, effectively suppressing measurement noise and improving the output traveling wave signal. The waveform purity is excellent. The circumferential sinusoidal distribution conductor can completely cover the periodic changes of the circumferential precision measurement excitation magnetic field. The moving part can stably couple and modulate the magnetic field throughout its rotation, outputting a traveling wave signal with excellent sinusoidal properties, ensuring the linearity of angular displacement measurement and the stability of position recognition.

[0020] The first axial coarse measuring conductor segment of the first induction coil and the first axial fine measuring conductor segment of the third induction coil are distributed in the same layer; the second axial coarse measuring conductor segment of the first induction coil and the second axial fine measuring conductor segment of the third induction coil are also distributed in the same layer; the starting ends of the first induction coil and the starting ends of the third induction coil are aligned axially and spaced apart circumferentially. ;in, , This represents the minimum angle between the first and third induction coils in the circumferential direction. Arranging the corresponding conductor segments for axial coarse and fine measurements in the same layer reduces the number of induction coil layers on the mover, simplifies the mover substrate's stacked structure, reduces parasitic inductance and interlayer electromagnetic crosstalk caused by multi-layer wiring, and simultaneously reduces the overall axial size of the sensor, resulting in a more compact structure. With the axial starting positions of the coarse and fine induction coils aligned, their axial spatial references are unified, and there is no inherent axial phase difference between the coarse and fine displacement signals. This eliminates the need for additional axial phase correction logic during backend fusion calculation, reducing algorithm complexity and controller computational power consumption.

[0021] The first circumferential coarse measuring conductor segment of the second induction coil and the first circumferential fine measuring conductor segment of the fourth induction coil are distributed in the same layer; the second circumferential coarse measuring conductor segment of the second induction coil and the second circumferential fine measuring conductor segment of the fourth induction coil are distributed in the same layer; the starting ends of the second induction coil and the starting ends of the fourth induction coil are aligned circumferentially and spaced apart axially. ,in, , This represents the minimum distance between the second and fourth induction coils along the axial direction. Arranging the corresponding conductor segments for circumferential coarse and fine measurements in the same layer reduces the number of induction coil layers on the mover, simplifies the mover substrate's stacked structure, reduces parasitic inductance and interlayer electromagnetic crosstalk caused by multi-layer wiring, and simultaneously reduces the overall axial size of the sensor, resulting in a more compact structure. With the circumferential starting positions of the coarse and fine induction coils aligned, their circumferential spatial references are unified, and there is no inherent axial phase difference between the coarse and fine displacement signals. This eliminates the need for additional axial phase correction logic during backend fusion calculation, reducing algorithm complexity and controller computational power consumption.

[0022] The absolute displacement sensor has three working modes: independent linear displacement measurement mode, independent angular displacement measurement mode, and combined linear and angular displacement measurement mode.

[0023] When using the independent linear displacement measurement mode, the mover moves linearly relative to the stator along the axial direction. First, two sinusoidal current excitation signals of the same frequency and amplitude are applied to the first and second coarse axial measurement excitation groups, respectively. , The circumferential coarse measurement excitation coil array, the axial fine measurement excitation coil array, and the circumferential fine measurement excitation coil array are all grounded, and the first induction coil outputs a traveling wave signal. And store; then, quickly transfer the sine and cosine current excitation signals. , Switching to the first and second excitation groups for axial precision measurement, the axial coarse measurement excitation coil array, the circumferential coarse measurement excitation coil array, and the circumferential precision measurement excitation coil array are all grounded, and the third induction coil outputs a traveling wave signal. For traveling wave signals Modulation and high-frequency clock interpolation are performed to obtain the coarse linear displacement. For traveling wave signals Modulation and high-frequency clock interpolation are performed to obtain the precise linear displacement. ;right , Perform absolute displacement calculations to obtain the absolute linear displacement values. In the independent linear displacement measurement mode, orthogonal sine and cosine excitations are applied only to the coarse and fine axial excitation components. The remaining excitation coil arrays are uniformly grounded and shielded, completely isolating magnetic field coupling interference from the circumferential channel and the other precision axial channel. This eliminates signal crosstalk caused by rotational motion and improves the signal-to-noise ratio of linear displacement measurement. A time-division excitation sequence is adopted, first acquiring and buffering the coarse traveling wave signal, then quickly switching to the fine measurement channel to acquire the high-precision signal. The hardware requires only one set of orthogonal excitation generation circuits, simplifying the back-end drive circuit design. The coarse and fine measurement signals are fused to calculate the absolute linear displacement, eliminating the need for zero-reset upon power-up, while simultaneously achieving both large-range positioning and high-resolution measurement accuracy.

[0024] When using the independent angular displacement measurement mode, the mover rotates relative to the stator in the circumferential direction. First, two sinusoidal current excitation signals of the same frequency and amplitude are applied to the first and second excitation groups of the circumferential coarse measurement. , The axial coarse measurement excitation coil array, the axial fine measurement excitation coil array, and the circumferential fine measurement excitation coil array are all grounded, and the second induction coil outputs a traveling wave signal. And store; then, quickly transfer the sine and cosine current excitation signals. , Switching to the first and second excitation groups for circumferential precision measurement, the axial coarse measurement excitation coil array, the circumferential coarse measurement excitation coil array, and the axial precision measurement excitation coil array are all grounded, and the fourth induction coil outputs a traveling wave signal. For traveling wave signals Modulation and high-frequency clock interpolation are performed to obtain the coarse angular displacement. For traveling wave signals Modulation and high-frequency clock interpolation are performed to obtain the precise angular displacement. ;right , Perform absolute displacement calculations to obtain absolute angular displacement values. In the independent angular displacement measurement mode, orthogonal sine and cosine excitations are applied only to the coarse and fine circumferential excitation components, while the remaining excitation coil arrays are uniformly grounded and shielded. This completely isolates the magnetic field coupling interference from the axial channel and the other precision circumferential channel, eliminating signal crosstalk caused by rotational motion and improving the signal-to-noise ratio of angular displacement measurement. A time-division excitation sequence is adopted, first acquiring and buffering the traveling wave signal from the coarse measurement, then quickly switching to the fine measurement channel to acquire the high-precision signal. The hardware requires only one set of orthogonal excitation generation circuits, simplifying the design of the back-end drive circuit. The coarse and fine measurement signals are fused to calculate the absolute angular displacement, eliminating the need for zero-reset upon power-up, while simultaneously achieving both large-range positioning and high-resolution measurement accuracy.

[0025] When using the combined linear and angular displacement measurement mode, the mover moves linearly and rotates relative to the stator simultaneously. First, two sinusoidal current excitation signals of the same frequency and amplitude are applied to the first and second axial coarse measurement excitation groups, respectively. , Two sinusoidal current excitation signals of the same frequency and equal amplitude are applied to the first excitation group and the second excitation group of the circumferential coarse measurement, respectively. , The axial precision measurement excitation coil array and the circumferential precision measurement excitation coil array are grounded, and the first induction coil outputs a traveling wave signal. The signal is stored, and the second induction coil outputs a traveling wave signal. And store; then, quickly transfer the sine and cosine current excitation signals. , Switching to the first and second excitation groups of axial precision measurement, the sine and cosine current excitation signals are applied. , Switching to the first and second excitation groups for circumferential precision measurement, the axial coarse measurement excitation coil array and the circumferential coarse measurement excitation coil array are grounded, and the third induction coil outputs a traveling wave signal. The fourth induction coil outputs a traveling wave signal. For traveling wave signals Modulation and high-frequency clock interpolation are performed to obtain the coarse linear displacement. For traveling wave signals Modulation and high-frequency clock interpolation are performed to obtain the coarse angular displacement. For traveling wave signals Modulation and high-frequency clock interpolation are performed to obtain the precise linear displacement. For traveling wave signals Modulation and high-frequency clock interpolation are performed to obtain the precise angular displacement. ;right , Perform absolute displacement calculations to obtain the absolute linear displacement values. ,right , Perform absolute displacement calculations to obtain absolute angular displacement values. The composite measurement mode simultaneously applies two independent orthogonal excitations to the axial and circumferential coarse measurement excitation groups, while the idle axial and circumferential fine measurement excitation coil arrays are grounded and shielded. It can simultaneously acquire and buffer linear and angular coarse measurement signals, obtaining two types of displacement coarse positioning information at once, adapting to linear + rotational linkage conditions of the mover. Time-division switching of excitation to the axial and circumferential fine measurement excitation groups, with synchronous grounding and isolation of the axial and circumferential coarse measurement excitation coil arrays, and the time-division acquisition mechanism avoids crosstalk from the superposition of magnetic fields in the coarse and fine channels, ensuring the purity of the four traveling wave signal waveforms and preventing interference between linear and angular measurements.

[0026] right , Perform absolute displacement calculations to obtain the absolute linear displacement values. The method is as follows:

[0027] First use and Perform axial pole alignment to determine the number of axial poles traversed by the mover. .

[0028] Reuse formula: Calculate the absolute linear displacement value Where, 0≤ ≤N1-1.

[0029] right , Perform absolute displacement calculations to obtain absolute angular displacement values. The method is as follows:

[0030] First use and Perform circumferential pole positioning to determine the number of circumferential pole pairs traversed by the mover. .

[0031] Reuse formula: Calculate the absolute angular displacement value Where, 0≤ ≤N2-1.

[0032] This invention achieves integrated absolute measurement of angular and linear displacements, offering advantages such as natural decoupling and non-interference between angular and linear displacement measurements, elimination of Abbe error, no need for manual zeroing upon power-up, and automatic data retention after power-off. These advantages significantly improve ease of use and measurement reliability. The time-division excitation mechanism for coarse and fine measurements not only effectively reduces the overall power consumption of the sensor but also facilitates electrical decoupling of circumferential and axial sensing signals, making the calculation of angular and linear displacements more convenient and efficient. Both the excitation and sensing units are manufactured using FPC technology, eliminating the need for ultra-precision engraving processes and effectively reducing production costs. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the absolute displacement sensor used in the embodiment for combined measurement of magnetic field angular displacement and linear displacement.

[0034] Figure 2 This is a top-view cross-sectional view of the sensor in the embodiment.

[0035] Figure 3 The images show the front view, top view, and partial schematic diagram of the axial coarse measurement excitation coil array in the embodiment.

[0036] Figure 4 The images show front view, top view, and partial schematic diagram of the circumferential coarse measurement excitation coil array in the embodiment.

[0037] Figure 5 The images show the front view, top view, and partial schematic diagram of the axial precision measurement excitation coil array in the embodiment.

[0038] Figure 6 The images show the front view, top view, and partial schematic diagram of the circumferential precision measurement excitation coil array in the embodiment.

[0039] Figure 7 This is a diagram showing the positional relationship between the first and third induction coils after they are unfolded circumferentially in the embodiment.

[0040] Figure 8 This is a diagram showing the positional relationship between the second and fourth induction coils after they are unfolded circumferentially in the embodiment.

[0041] Figure 9 This is a block diagram illustrating the signal processing principle of the combined linear and angular displacement measurement in this embodiment. Detailed Implementation

[0042] like Figures 1 to 8 As shown, the absolute displacement sensor for combined magnetic field angular displacement and linear displacement measurement in this embodiment includes a stator and a mover. The mover is coaxially sleeved outside the stator with a 0.5mm gap (i.e., Figure 2 In The stator includes a stator base 1 and an excitation unit 10 disposed on the outer cylindrical surface of the stator base 1. The outer diameter of the stator base 1 is [missing information]. The mover includes a mover base 2 and a sensing unit 20 disposed on the inner cylindrical surface of the mover base 2. The inner diameter of the mover base 2 is... Let the circumferential direction (i.e., the direction of a circle) be designated as the X-axis, and the axial direction (i.e., the direction of the axis) as the Y-axis. As an example, , .

[0043] like Figures 2 to 6 As shown, the excitation unit 10 includes an axial coarse measurement excitation coil array 11, a circumferential coarse measurement excitation coil array 12, an axial fine measurement excitation coil array 13, and a circumferential fine measurement excitation coil array 14, which are located on different layers and are insulated from each other.

[0044] like Figure 3 As shown, in some embodiments, the axial coarse measurement excitation coil array 11 consists of 4M1 identical first coils evenly spaced along the axial direction. The arrangement consists of a first coil that unfolds circumferentially into a rectangle. The long side of the first coil is curled circumferentially and fixed to the outer surface of the stator base 1, with a curling radius of [missing information]. The gap angle between the two short sides after curling is The central angle subtended by the length of the first coil is Therefore, the length of the first coil is Width is In the axial direction, the first The first coil is wound forward, the second... The first coil is reverse-wound, and the second... The first coil and the first The first coils are connected in series to form the first excitation group 111 for axial coarse measurement; in the axial direction, the first... The first coil is wound forward, the second... The first coil is reverse-wound, and the second... The first coil and the first The first coils are connected in series to form the second excitation group 112 for axial coarse measurement. Among them, Take all integers from 0 to M1-1 in sequence, where M1 represents the number of pole pairs of the axial coarse measurement excitation coil array 11. This indicates the pole pitch of the axial coarse measurement excitation coil array 11. .

[0045] As an example, M1=5, , , , , , .

[0046] like Figure 4 As shown, in some embodiments, the circumferential coarse measurement excitation coil array 12 consists of 4M2 identical second coils evenly spaced circumferentially. The arrangement consists of a second coil that unfolds circumferentially into a rectangle. The short side of the second coil is curled circumferentially and coaxially fixed to the outer surface of the axial coarse-measured excitation coil array 11, with a curling radius of [missing information]. The central angle subtended by the width of the second coil is Therefore, the width of the second coil is The length is L1; in the circumferential direction (i.e., the circumferential direction), the first... The second coil is wound forward, the first... The second coil is reverse-wound, and the first... The second coil and the first The second coils are connected in series to form the first excitation group 121 for circumferential coarse measurement; in the circumferential direction (i.e., the circular direction), the first... The second coil is wound forward, the first... The second coil is reverse-wound, and the first... The second coil and the first The second coils are connected in series to form the second excitation group 122 for circumferential coarse measurement. Among them, Take all integers from 0 to M2-1 in sequence. M2 represents the number of pole pairs in the circumferential coarse excitation coil array 12. This represents the central angle subtended by the pole pitch of the circumferential coarse measurement excitation coil array 12. .

[0047] As an example, M2=5, , , , , L1 = 64 mm.

[0048] like Figure 5 As shown, in some embodiments, the axial precision excitation coil array 13 and the axial coarse excitation coil array 11 have the same starting position in the axial direction. The axial precision excitation coil array 13 consists of 4N1 identical third coils evenly spaced along the axial direction. The arrangement consists of a third coil that unfolds circumferentially into a rectangle. The long side of the third coil is curled circumferentially and coaxially fixed to the outer surface of the circumferential coarse-measuring excitation coil array 12, with a curling radius of [missing information]. The gap angle between the two short sides after curling is The central angle subtended by the length of the third coil is Therefore, the length of the third coil is Width is ; In the axial direction, the 4th +1 third coil is wound forward, 4th... +3 third coils reverse-wound, and the first The third coil and the first The third coil is connected in series to form the first excitation group 131 for axial precision measurement; in the axial direction, the fourth... +2 third coils are wound forward, the 4th... +4 third coils reverse-wound, and the first The third coil and the first The third coil is connected in series to form the second excitation group 132 for axial precision measurement. Among them, Take all integers from 0 to N1-1 in sequence. The gap angle between the two short sides of the third coil is represented by N1, which represents the number of pole pairs in the axial precision excitation coil array 13. N1 and M1 are coprime. , This indicates the pole pitch of the axial precision measuring excitation coil array 13. .

[0049] As an example, N1=8, , , , ,, , .

[0050] like Figure 6 As shown, in some embodiments, the circumferential precision excitation coil array 14 and the circumferential coarse excitation coil array 12 have the same starting position. The circumferential precision excitation coil array 14 consists of 4N2 identical fourth coils evenly spaced circumferentially. The arrangement consists of a fourth coil that unfolds circumferentially into a rectangle. The short side of the fourth coil is curled circumferentially and coaxially fixed on the outer surface of the axial precision excitation coil array 13, with a curling radius of [missing information]. The central angle subtended by the width of the fourth coil is Therefore, the width of the fourth coil is The length is L2; ​​in the circumferential direction, the first... The fourth coil is wound, the... The fourth coil is reverse-wound, and the... The fourth coil and the first The fourth coil is connected in series to form the first excitation group 141 for circumferential precision measurement; in the circumferential direction, the fourth coil... The fourth coil is wound, the... The fourth coil is reverse-wound, and the... The fourth coil and the first The fourth coil is connected in series to form the second excitation group 142 for circumferential precision measurement; among which... Take all integers from 0 to N²-1 in sequence. N2 represents the number of pole pairs of the circumferential precision excitation coil array 14, and N2 and M2 are coprime. This represents the central angle subtended by the pole pitch of the circumferential precision measuring excitation coil array 14. .

[0051] As an example, N2=8, , , , , L2 = 64mm.

[0052] Sensor circumferential total range Total axial range of the sensor The total range of the sensor is 360° × 64mm. The first coil in the axial coarse measurement excitation coil array 11 has a total axial length (including gaps) of 64mm, which covers the sensor's axial coarse measurement range. The second coil in the circumferential coarse measurement excitation coil array 12 rotates 360° circumferentially, covering the sensor's circumferential coarse measurement range. The third coil in the axial fine measurement excitation coil array 13 has a total axial length (including gaps) of 64mm, covering the sensor's axial fine measurement range. The fourth coil in the circumferential fine measurement excitation coil array 14 rotates 360° circumferentially, covering the sensor's circumferential fine measurement range.

[0053] like Figure 7 , Figure 8 As shown, the sensing unit 20 includes a first induction coil 21, a second induction coil 22, a third induction coil 23, and a fourth induction coil 24. The first induction coil 21 is directly coupled to the axial coarse measurement excitation coil array 11, the second induction coil 22 is directly coupled to the circumferential coarse measurement excitation coil array 12, the third induction coil 23 is directly coupled to the axial fine measurement excitation coil array 13, and the fourth induction coil 24 is directly coupled to the circumferential fine measurement excitation coil array 14.

[0054] like Figure 7 As shown, in some embodiments, the first induction coil 21 is composed of two axially coarse-measured first conductor segment 211 and axially coarse-measured second conductor segment 212, which form a sinusoidal waveform when unfolded circumferentially. The starting ends of the axially coarse-measured first conductor segment 211 and the axially coarse-measured second conductor segment 212 are connected by vias, and the ending ends serve as traveling wave signals. At the output end, the winding curve of the first conductor segment 211, measured axially, is as follows: The axial rough measurement of the winding curve of the second conductor segment 212 is as follows: .in, , , Indicates the winding curve The radius of curvature, Indicates the winding curve The radius of curvature. As an example. , .

[0055] like Figure 8 As shown, in some embodiments, the second induction coil 22 is composed of two circumferential coarse measuring first wire segment 221 and circumferential coarse measuring second wire segment 222, which form a sinusoidal waveform when unfolded circumferentially. The starting ends of the circumferential coarse measuring first wire segment 221 and circumferential coarse measuring second wire segment 222 are connected by vias, and the ending ends serve as traveling wave signals. At the output end, the first conductor segment 221, after being unfolded circumferentially, has M2 peaks and M2 troughs, and the second conductor segment 222, after being unfolded circumferentially, has M2 troughs and M2 peaks. The winding curve of the first conductor segment 221 is as follows: The circumferential rough measurement of the winding curve of the second conductor segment 222 is as follows: .in, , , Indicates the winding curve The radius of curvature, Indicates the winding curve The radius of curvature, This indicates the amplitude of the circumferential coarse measurement of the first conductor segment 221. As an example, , , The first traverse segment 221, when roughly measured circumferentially, has 5 peaks and 5 troughs when unfolded circumferentially. The second traverse segment 222, when roughly measured circumferentially, has 5 troughs and 5 peaks when unfolded circumferentially.

[0056] As an example, the axial coarse-measuring first conductor segment 211 of the first induction coil 21 and the axial fine-measuring first conductor segment 231 of the third induction coil 23 are distributed in the same layer, and the axial coarse-measuring second conductor segment 212 of the first induction coil 21 and the axial fine-measuring second conductor segment 232 of the third induction coil 23 are distributed in the same layer. The starting ends of the first induction coil 21 and the starting ends of the third induction coil 23 are aligned axially and spaced apart circumferentially. ;in, , representing the minimum angle between the first induction coil 21 and the third induction coil 23 in the circumferential direction (i.e., the angle between the trough of the axial coarse measurement of the first conductor segment 211 and the crest of the axial fine measurement of the first conductor segment 231 in the circumferential direction). As an example, .

[0057] like Figure 7As shown, in some embodiments, the third induction coil 23 is composed of two axial precision measurement first conductor segment 231 and axial precision measurement second conductor segment 232, which form a sinusoidal waveform when unfolded circumferentially. The starting ends of the axial precision measurement first conductor segment 231 and the axial precision measurement second conductor segment 232 are connected by vias, and the ending ends serve as traveling wave signals. At the output end, the winding curve of the first conductor segment 231, measured axially, is as follows: The winding curve of the second conductor segment 232, measured axially, is as follows: .in, , , winding curve The radius of curvature is also and winding curve The radius of curvature is also .

[0058] like Figure 8 As shown, in some embodiments, the fourth induction coil 24 is composed of two circumferentially precise measurement first conductor segment 241 and circumferentially precise measurement second conductor segment 242, which unfold in the circumferential direction and form a sinusoidal waveform. The starting ends of the circumferentially precise measurement first conductor segment 241 and circumferentially precise measurement second conductor segment 242 are connected by vias, and the ending ends serve as traveling wave signals. At the output end, the first circumferentially measured conductor segment 241, after being unfolded circumferentially, has N2 peaks and N2 troughs, and the second circumferentially measured conductor segment 242, after being unfolded circumferentially, has N2 troughs and N2 peaks. The winding curve of the first circumferentially measured conductor segment 241 is as follows: The winding curve of the second conductor segment 242, measured circumferentially, is as follows: .in, , , winding curve The radius of curvature is also , winding curve The radius of curvature is also , This indicates the amplitude of the circumferentially measured first traverse segment 241. As an example, The first traverse segment 241 of the circumferential precision survey has 8 peaks and 8 valleys when unfolded circumferentially, and the second traverse segment 242 of the circumferential precision survey has 8 valleys and 8 peaks when unfolded circumferentially.

[0059] In some embodiments, the circumferential coarse measuring first conductor segment 221 of the second induction coil 22 and the circumferential fine measuring first conductor segment 241 of the fourth induction coil 24 are distributed in the same layer, and the circumferential coarse measuring second conductor segment 222 of the second induction coil 22 and the circumferential fine measuring second conductor segment 242 of the fourth induction coil 24 are distributed in the same layer; the starting ends of the second induction coil 22 and the starting ends of the fourth induction coil 24 are aligned circumferentially and spaced apart axially. .in, , This represents the minimum distance between the second and fourth induction coils along the axial direction (i.e., the distance between the trough of the circumferentially coarsely measured first conductor segment 221 and the crest of the circumferentially finely measured first conductor segment 241). As an example, .

[0060] The aforementioned absolute displacement sensor has independent linear displacement measurement mode, independent angular displacement measurement mode, and combined linear and angular displacement measurement mode.

[0061] When using the independent linear displacement measurement mode, the mover moves linearly relative to the stator along the axial direction. First, two sinusoidal current excitation signals of the same frequency and amplitude are applied to the first excitation group 111 and the second excitation group 112 of the axial coarse measurement. , At this time, the circumferential coarse measurement excitation coil array 12, the axial fine measurement excitation coil array 13, and the circumferential fine measurement excitation coil array 14 are all grounded, and the first induction coil 21 outputs a traveling wave signal. And store it; then, quickly (e.g., within 100 ns) apply the sine and cosine current excitation signals. , Switching to the first excitation group 131 for axial precision measurement and the second excitation group 132 for axial precision measurement, at this time, the axial coarse measurement excitation coil array 11, the circumferential coarse measurement excitation coil array 12, and the circumferential precision measurement excitation coil array 14 are all grounded, and the third induction coil 23 outputs a traveling wave signal. For traveling wave signals Modulation and high-frequency clock interpolation are performed to obtain the coarse linear displacement. For traveling wave signals Modulation and high-frequency clock interpolation are performed to obtain the precise linear displacement. ;right , Perform absolute displacement calculations to obtain the absolute linear displacement values. .

[0062] When using the independent angular displacement measurement mode, the mover rotates relative to the stator in the circumferential direction. First, two sinusoidal current excitation signals of the same frequency and amplitude are applied to the first excitation group 121 and the second excitation group 122 of the circumferential coarse measurement. , At this time, the axial coarse measurement excitation coil array 11, the axial fine measurement excitation coil array 13, and the circumferential fine measurement excitation coil array 14 are all grounded, and the second induction coil 22 outputs a traveling wave signal. And store it; then, quickly (e.g., within 100 ns) apply the sine and cosine current excitation signals. , Switching to the first excitation group 141 and the second excitation group 142 for circumferential precision measurement, at this time, the axial coarse measurement excitation coil array 11, the circumferential coarse measurement excitation coil array 12, and the axial precision measurement excitation coil array 13 are all grounded, and the fourth induction coil 24 outputs a traveling wave signal. For traveling wave signals Modulation and high-frequency clock interpolation are performed to obtain the coarse angular displacement. For traveling wave signals Modulation and high-frequency clock interpolation are performed to obtain the precise angular displacement. ;right , Perform absolute displacement calculations to obtain absolute angular displacement values. .

[0063] like Figure 9 As shown, when using the combined linear and angular displacement measurement mode, the mover moves linearly and rotates relative to the stator simultaneously. First, two sinusoidal current excitation signals of the same frequency and amplitude are applied to the first excitation group 111 of axial coarse measurement and the second excitation group 112 of axial coarse measurement, respectively. , Two sinusoidal current excitation signals of the same frequency and equal amplitude are applied to the first excitation group 121 and the second excitation group 122 of the circumferential coarse measurement, respectively. , ;in, This represents the amplitude of the excitation signal and the angular frequency of the excitation signal. At this time, the axial precision measurement excitation coil array 13 and the circumferential precision measurement excitation coil array 14 are grounded (i.e., the axial precision measurement excitation coil array 13 and the circumferential precision measurement excitation coil array 14 are not working), and the first induction coil 21 outputs a traveling wave signal. And store, the second induction coil 22 outputs a traveling wave signal. And store. Among them, , , , It is a constant. , The initial phase of the fundamental component. This indicates a rough measurement of linear displacement. This indicates a coarse measurement of angular displacement.

[0064] Then, the sine and cosine current excitation signals are rapidly (e.g., within 100 ns). , Switch to the first excitation group 131 and the second excitation group 132 of axial precision measurement, and apply the sine and cosine current excitation signals. , Switch to the first excitation group 141 and the second excitation group 142 for circumferential precision measurement; at this time, the axial coarse measurement excitation coil array 11 and the circumferential coarse measurement excitation coil array 12 are grounded (i.e., the axial coarse measurement excitation coil array 11 and the circumferential coarse measurement excitation coil array 12 are not working), and the third induction coil 23 outputs a traveling wave signal. The fourth induction coil 24 outputs a traveling wave signal. .in, , , , It is a constant. , The initial phase of the fundamental component. Indicates precise linear displacement. This indicates the precise measurement of angular displacement.

[0065] For traveling wave signals Modulation is performed (the modulated signal loses only amplitude information unrelated to the coarse linear displacement, while phase information related to the coarse linear displacement is retained) to obtain a square wave signal, which is then compared with the traveling wave signal. Modulation is performed (the modulated signal loses only amplitude information unrelated to the coarse angular displacement, while phase information related to the coarse angular displacement is retained) to obtain a square wave signal, which is then compared with the traveling wave signal. Modulation is performed (the modulated signal loses only amplitude information unrelated to the precise linear displacement, while the phase information related to the precise linear displacement is retained) to obtain a square wave signal, which is then compared with the traveling wave signal. Modulation is performed (the modulated signal loses only the amplitude information that is irrelevant to the precise angular displacement, while the phase information that is relevant to the precise angular displacement is retained) to obtain a square wave signal.

[0066] The four square wave signals are then compared with a reference signal of the same frequency. The phase difference is interpolated using a high-frequency clock pulse to calculate the coarse phase within the pole pair of the axial measurement. Circumferential coarse measurement of the inner phase of the pole Axial precision measurement of the inner phase of the pole and circumferential precision measurement of the inner phase of the pole .in, , , , .

[0067] Ultimately, , , and The data is transmitted to the host computer via serial port, where a preliminary calculation is performed to obtain the coarse linear displacement. Coarse measurement of angular displacement Precise measurement of linear displacement Precise measurement of angular displacement .

[0068] In some embodiments, first utilize and Perform axial pole alignment (a prior art technique) to determine the number of axial poles traversed by the mover. Reusing the formula: The absolute linear displacement value was calculated. Where, 0≤ ≤N1-1.

[0069] In some embodiments, first utilize and Perform circumferential pole positioning (a prior art technique) to determine the number of circumferential poles traversed by the mover. Reusing the formula: The absolute angular displacement value was calculated. Where, 0≤ ≤N2-1.

Claims

1. An absolute displacement sensor for combined magnetic field angular and linear displacement measurement, comprising a stator and a mover, the mover being coaxially sleeved outside the stator with a gap, the stator comprising a stator base (1) and an excitation unit (10) disposed on the outer cylindrical surface of the stator base (1), the mover comprising a mover base (2) and a sensing unit (20) disposed on the inner cylindrical surface of the mover base (2); characterized in that: The excitation unit (10) includes an axial coarse measurement excitation coil array (11), a circumferential coarse measurement excitation coil array (12), an axial fine measurement excitation coil array (13), and a circumferential fine measurement excitation coil array (14) located in different layers and insulated from each other. The sensing unit (20) includes a first sensing coil (21), a second sensing coil (22), a third sensing coil (23), and a fourth sensing coil (24); the first sensing coil (21) is directly coupled to the axial coarse measurement excitation coil array (11), the second sensing coil (22) is directly coupled to the circumferential coarse measurement excitation coil array (12), the third sensing coil (23) is directly coupled to the axial fine measurement excitation coil array (13), and the fourth sensing coil (24) is directly coupled to the circumferential fine measurement excitation coil array (14). When the mover moves linearly and / or rotates relative to the stator, an excitation signal is first applied to the axial coarse measurement excitation coil array (11) and / or the circumferential coarse measurement excitation coil array (12), the remaining excitation coil array is grounded, and the first induction coil (21) and / or the second induction coil (22) output a traveling wave signal. and / or And store; then, quickly switch the excitation signal to the axial precision excitation coil array (13) and / or the circumferential precision excitation coil array (14), the remaining excitation coil array is grounded, and the third induction coil (23) and / or the fourth induction coil (24) output traveling wave signals. and / or For traveling wave signals and / or After processing, the coarse linear displacement is obtained. and / or coarse angular displacement For traveling wave signals and / or The process is performed to obtain the precise linear displacement. and / or precise measurement of angular displacement ,right , and / or , Perform absolute displacement calculations to obtain the absolute linear displacement values. and / or absolute angular displacement value .

2. The absolute displacement sensor for combined measurement of magnetic field angular displacement and linear displacement according to claim 1, characterized in that: The axial coarse excitation coil array (11) consists of 4M1 identical first coils evenly spaced along the axial direction. The arrangement consists of a first coil that, when unfolded circumferentially, forms a rectangle. The central angle subtended by the length of the first coil is... Width is ;No. The first coil is wound forward, the second... The first coil is reverse-wound and connected in series to form the first excitation group (111) for axial coarse measurement; The first coil is wound forward, the second... The first coil is reverse-wound and connected in series to form the second excitation group (112) for axial coarse measurement; wherein, Take all integers from 0 to M1-1 in sequence. M1 represents the gap angle between the two short sides of the first coil, and M1 represents the number of poles of the axial coarse excitation coil array (11). The circumferential coarse excitation coil array (12) consists of 4M2 identical second coils evenly spaced circumferentially. The arrangement consists of a second coil that unfolds into a rectangle along its circumference. The length of the second coil is L1, and the central angle subtended by its width is... ;No. The second coil is wound forward, the first... The second coil is reverse-wound and connected in series to form the first excitation group (121) for circumferential coarse measurement; The second coil is wound forward, the first... The second coil is reverse-wound and connected in series to form the second excitation group (122) for circumferential coarse measurement; among which, Take all integers from 0 to M2-1 in sequence. M2 represents the number of pole pairs of the circumferential coarse excitation coil array (12); The axial precision excitation coil array (13) and the axial coarse excitation coil array (11) have the same starting position in the axial direction; The axial precision excitation coil array (13) consists of 4N1 identical third coils evenly spaced along the axial direction. The arrangement is such that the third coil, when unfolded circumferentially, forms a rectangle, and the central angle subtended by the length of the third coil is... Width is ;4th +1 third coil is wound forward, 4th... +3 third coils are reverse-wound and connected in series to form the first excitation group (131) for axial precision measurement; the 4th +2 third coils are wound forward, the 4th... +4 third coils are reverse-wound and connected in series to form the second excitation group (132) for axial precision measurement; among them, Take all integers from 0 to N1-1 in sequence. The gap angle between the two short sides of the third coil is represented by N1, which represents the number of pole pairs of the axial precision excitation coil array (13). N1 and M1 are coprime, and ; The circumferential precision excitation coil array (14) and the circumferential coarse excitation coil array (12) have the same starting position. The circumferential precision excitation coil array (14) consists of 4N2 identical fourth coils evenly spaced circumferentially. The arrangement consists of four coils. The fourth coil, when unfolded circumferentially, forms a rectangle. The length of the fourth coil is L2, and the central angle subtended by its width is... ;No. The fourth coil is wound, the... The fourth coil is reverse-wound and connected in series to form the first excitation group (141) for circumferential precision measurement; The fourth coil is wound, the... The fourth coil is reverse-wound and connected in series to form the second excitation group (142) for circumferential precision measurement; among which, Take all integers from 0 to N²-1 in sequence. N2 represents the number of poles of the circumferential precision excitation coil array (14), and N2 and M2 are coprime.

3. The absolute displacement sensor for combined measurement of magnetic field angular displacement and linear displacement according to claim 2, characterized in that: The first induction coil (21) is composed of two axial coarse-measured first conductor segment (211) and axial coarse-measured second conductor segment (212) that unfold in the circumferential direction and form a sinusoidal waveform. The starting ends of the axial coarse-measured first conductor segment (211) and the axial coarse-measured second conductor segment (212) are connected by vias, and the ending ends serve as traveling wave signals. At the output end, the winding curve of the first conductor segment (211) is roughly measured axially as follows: The axial rough measurement of the winding curve of the second conductor segment (212) is as follows: ;in, , , Indicates the winding curve The radius of curvature, Indicates the winding curve The radius of curvature, This indicates the pole pitch of the axial coarse measurement excitation coil array (11). ; The second induction coil (22) consists of two circumferential coarse measurement first conductor segment (221) and circumferential coarse measurement second conductor segment (222), which unfold into a sinusoidal waveform along the circumference. The starting ends of the circumferential coarse measurement first conductor segment (221) and the circumferential coarse measurement second conductor segment (222) are connected by vias, and the ending ends serve as traveling wave signals. At the output end, the winding curve of the first conductor segment (221) is roughly measured in the circumferential direction as follows: The circumferential rough measurement of the winding curve of the second conductor segment (222) is as follows: ;in, , , Indicates the winding curve The radius of curvature, Indicates the winding curve The radius of curvature, This represents the central angle subtended by the pole pitch of the circumferential coarse excitation coil array (12). , This indicates the amplitude of the circumferential coarse measurement of the first traverse segment (221). ; The third induction coil (23) is composed of two axial precision measurement first conductor segment (231) and axial precision measurement second conductor segment (232) that unfold in the circumferential direction and form a sinusoidal waveform. The starting ends of the axial precision measurement first conductor segment (231) and the axial precision measurement second conductor segment (232) are connected by through holes, and the ending ends serve as traveling wave signals. At the output end, the winding curve of the first conductor segment (231) is accurately measured axially. The winding curve of the second conductor segment (232) is determined by axial precision measurement. ;in, , , This indicates the pole pitch of the axial precision excitation coil array (13). ; The fourth induction coil (24) is composed of two circumferential precision measurement first conductor segment (241) and circumferential precision measurement second conductor segment (242) that unfold in the circumferential direction and form a sinusoidal waveform. The starting ends of the circumferential precision measurement first conductor segment (241) and the circumferential precision measurement second conductor segment (242) are connected by vias, and the ending ends serve as traveling wave signals. At the output end, the winding curve of the first conductor segment (241) in the circumferential precision measurement is as follows: The winding curve of the second conductor segment (242) is determined by circumferential precision measurement. ;in, , , This represents the amplitude of the first traverse segment (241) measured circumferentially. This represents the central angle subtended by the pole pitch of the circumferential precision excitation coil array (14). , .

4. The absolute displacement sensor for combined measurement of magnetic field angular displacement and linear displacement according to claim 3, characterized in that: The first axial coarse measurement guide segment (211) and the first axial fine measurement guide segment (231) are distributed on the same layer, and the second axial coarse measurement guide segment (212) and the second axial fine measurement guide segment (232) are distributed on the same layer; the starting end of the first induction coil (21) and the starting end of the third induction coil (23) are aligned axially and spaced apart circumferentially. ;in, ; The first circumferential coarse measurement guide segment (221) and the first circumferential fine measurement guide segment (241) are distributed in the same layer, and the second circumferential coarse measurement guide segment (222) and the second circumferential fine measurement guide segment (242) are distributed in the same layer; the starting end of the second induction coil (22) and the starting end of the fourth induction coil (24) are aligned in the circumferential direction and spaced apart in the axial direction. ;in, .

5. The absolute displacement sensor for combined measurement of magnetic field angular displacement and linear displacement according to any one of claims 2 to 4, characterized in that: The absolute displacement sensor has an independent linear displacement measurement mode and an independent angular displacement measurement mode; When using the linear displacement independent measurement mode, the mover moves linearly relative to the stator along the axial direction. First, two sinusoidal current excitation signals of the same frequency and amplitude are applied to the first excitation group (111) and the second excitation group (112) of the axial coarse measurement. , The circumferential coarse measurement excitation coil array (12), the axial fine measurement excitation coil array (13), and the circumferential fine measurement excitation coil array (14) are all grounded, and the first induction coil (21) outputs a traveling wave signal. And store; then, quickly transfer the sine and cosine current excitation signals. , Switch to the first excitation group (131) and the second excitation group (132) for axial precision measurement. The axial coarse measurement excitation coil array (11), the circumferential coarse measurement excitation coil array (12), and the circumferential precision measurement excitation coil array (14) are all grounded. The third induction coil (23) outputs a traveling wave signal. For traveling wave signals Modulation and high-frequency clock interpolation are performed to obtain the coarse linear displacement. For traveling wave signals Modulation and high-frequency clock interpolation are performed to obtain the precise linear displacement. ;right , Perform absolute displacement calculations to obtain the absolute linear displacement values. ; When using the independent angular displacement measurement mode, the mover rotates relative to the stator in the circumferential direction. First, two sinusoidal current excitation signals of the same frequency and amplitude are applied to the first excitation group (121) and the second excitation group (122) of the circumferential coarse measurement. , The axial coarse measurement excitation coil array (11), the axial fine measurement excitation coil array (13), and the circumferential fine measurement excitation coil array (14) are all grounded, and the second induction coil (22) outputs a traveling wave signal. And store; then, quickly transfer the sine and cosine current excitation signals. , Switching to the first excitation group (141) and the second excitation group (142) of circumferential precision measurement, the axial coarse measurement excitation coil array (11), the circumferential coarse measurement excitation coil array (12), and the axial precision measurement excitation coil array (13) are all grounded, and the fourth induction coil (24) outputs a traveling wave signal. For traveling wave signals Modulation and high-frequency clock interpolation are performed to obtain the coarse angular displacement. For traveling wave signals Modulation and high-frequency clock interpolation are performed to obtain the precise angular displacement. ;right , Perform absolute displacement calculations to obtain absolute angular displacement values. .

6. The absolute displacement sensor for combined measurement of magnetic field angular displacement and linear displacement according to any one of claims 2 to 4, characterized in that: The absolute displacement sensor also has a combined linear and angular displacement measurement mode; When using the combined linear and angular displacement measurement mode, the mover moves linearly and rotates relative to the stator simultaneously. First, two sinusoidal current excitation signals of the same frequency and amplitude are applied to the first axial coarse measurement excitation group (111) and the second axial coarse measurement excitation group (112). , Two sinusoidal current excitation signals of the same frequency and equal amplitude are applied to the first excitation group (121) and the second excitation group (122) of the circumferential coarse measurement, respectively. , The axial precision excitation coil array (13) and the circumferential precision excitation coil array (14) are grounded, and the first induction coil (21) outputs a traveling wave signal. And store, the second induction coil (22) outputs a traveling wave signal. And store; then, quickly transfer the sine and cosine current excitation signals. , Switching to the first excitation group (131) and the second excitation group (132) for axial precision measurement, the sinusoidal and cosine current excitation signals are applied. , Switching to the first excitation group (141) and the second excitation group (142) of circumferential precision measurement, the axial coarse measurement excitation coil array (11) and the circumferential coarse measurement excitation coil array (12) are grounded, and the third induction coil (23) outputs a traveling wave signal. The fourth induction coil (24) outputs a traveling wave signal. For traveling wave signals Modulation and high-frequency clock interpolation are performed to obtain the coarse linear displacement. For traveling wave signals Modulation and high-frequency clock interpolation are performed to obtain the coarse angular displacement. For traveling wave signals Modulation and high-frequency clock interpolation are performed to obtain the precise linear displacement. For traveling wave signals Modulation and high-frequency clock interpolation are performed to obtain the precise angular displacement. ;right , Perform absolute displacement calculations to obtain the absolute linear displacement values. ,right , Perform absolute displacement calculations to obtain absolute angular displacement values. .

7. The absolute displacement sensor for combined measurement of magnetic field angular displacement and linear displacement according to any one of claims 1 to 4, characterized in that: right , Perform absolute displacement calculations to obtain the absolute linear displacement values. The method is as follows: First use and Perform axial pole alignment to determine the number of axial poles traversed by the mover. ; Reuse formula: Calculate the absolute linear displacement value Where, 0≤ ≤N1-1; right , Perform absolute displacement calculations to obtain absolute angular displacement values. The method is as follows: First use and Perform circumferential pole positioning to determine the number of circumferential pole pairs traversed by the mover. ; Reuse formula: Calculate the absolute angular displacement value Where, 0≤ ≤N2-1.

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