Layer-based absolute time-grid angular displacement sensor

Abstract

This invention relates to the field of precision angular displacement sensor technology, and provides an absolute time-grid angular displacement sensor based on a layered structure. The sensor includes an excitation electrode layer distributed on the surface of a first stator substrate, a sensing electrode layer and a reflective electrode layer distributed on the surface of a rotor substrate, and a receiving electrode layer distributed on the surface of a second stator substrate. In operation, this improves the signal-to-noise ratio, increases signal strength, and reduces signal transmission interference, thereby enhancing the measurement accuracy and reliability of the angular displacement sensor. The introduction of the multi-layered structure increases the sensing area on each substrate, further improving the quality of the angular displacement sensor's output. The differential structure of the receiving electrodes improves measurement stability, suppresses common-mode interference, enhances signal amplitude, and strengthens industrial adaptability. Furthermore, the special shape of the receiving electrodes improves the linearity of the output, resulting in higher accuracy for the angular displacement sensor under this modulation principle.

Description

Technical Field

[0001] This invention relates to the field of precision angular displacement sensor technology, and in particular to an absolute time-grid angular displacement sensor based on a layer structure. Background Technology

[0002] Angular displacement sensors are divided into incremental and absolute types. Compared with incremental sensors, absolute angular displacement sensors have advantages such as no need for reset upon power-on, immediate acquisition of absolute angle information, and no cumulative error, improving working efficiency and reliability, and thus gradually becoming the development trend of angular displacement sensors. Currently, the most widely used type is the absolute photoelectric encoder, which mainly achieves absolute positioning through encoding, but the encoding and decoding process is complex. Furthermore, precise markings are needed as a spatial reference for precise measurement, but the accuracy of the markings is limited by the processing equipment and technology. In recent years, domestically developed time-grating displacement sensors have adopted a time-to-space measurement method, eliminating the need for precise markings and achieving precise measurement, but the following problems still exist:

[0003] (1) The incremental counting method has a cumulative error;

[0004] (2) The excitation signal is input from the excitation electrode on the stator base of the sensor, and the induction signal is output from the rotor electrode on the rotor base. The rotor base needs to lead the signal output line, which cannot be used in some situations, resulting in a narrow application range. Furthermore, the installation of the signal output line is relatively troublesome. In industrial applications, under long-term high-speed operation, the signal output line wears out severely, which leads to a decrease in the reliability of the sensor. Summary of the Invention

[0005] This invention provides an absolute time-grid angular displacement sensor based on a layer structure to overcome the deficiencies in the prior art.

[0006] This invention provides an absolute time-grid angular displacement sensor based on a layer structure, comprising: a first stator base, a rotor base, and a second stator base that are coaxially and sequentially mounted;

[0007] An excitation electrode layer is distributed on the first surface of the first stator substrate facing the rotor substrate; an induction electrode layer is distributed on the second surface of the rotor substrate facing the first stator substrate; a reflection electrode layer is distributed on the third surface of the rotor substrate facing the second stator substrate; and a receiving electrode layer is distributed on the fourth surface of the second stator substrate facing the rotor substrate.

[0008] The excitation electrode on the excitation electrode layer, the induction electrode on the induction electrode layer, the reflection electrode on the reflection electrode layer, and the receiving electrode on the receiving electrode layer correspond one-to-one. The receiving electrode is a differential structure. The shape of the receiving electrode is a fully enclosed figure formed by two identical cosine polar coordinate curve segments in the interval [-π, 0] intersecting with concentric inner and outer circular arcs at the starting and ending points.

[0009] According to the present invention, an absolute time-grid angular displacement sensor based on a layer structure is provided, wherein the excitation electrode includes a first excitation electrode and a second excitation electrode, the sensing electrode includes a first sensing electrode and a second sensing electrode, the reflective electrode includes a first reflective electrode and a second reflective electrode, and the receiving electrode includes a first receiving electrode and a second receiving electrode, wherein the first excitation electrode, the first sensing electrode, the first reflective electrode and the first receiving electrode correspond to each other, and the second excitation electrode, the second sensing electrode, the second reflective electrode and the second receiving electrode correspond to each other.

[0010] Both the first excitation electrode and the second excitation electrode are used to receive the excitation signal of the target number of channels;

[0011] The first sensing electrode and the second sensing electrode are respectively used to couple with the first excitation electrode and the second excitation electrode, and respectively obtain the initial traveling wave signal of the target number of paths, and respectively transmit the initial traveling wave signal to the first reflecting electrode and the second reflecting electrode;

[0012] The first reflective electrode and the second reflective electrode are used to couple the initial traveling wave signal to the first receiving electrode and the second receiving electrode, respectively;

[0013] The first receiving electrode and the second receiving electrode are used to output two channels of first target traveling wave signal and second target traveling wave signal, respectively.

[0014] According to the present invention, an absolute time-grid angular displacement sensor based on a layer structure further includes a signal processing module, which is connected to the first receiving electrode and the second receiving electrode respectively.

[0015] The signal processing module is used to receive the first target traveling wave signal and the second target traveling wave signal, determine the first differential traveling wave signal corresponding to the first target traveling wave signal and the second differential traveling wave signal corresponding to the second target traveling wave signal, and determine and output the absolute angular displacement value based on the first differential traveling wave signal and the second differential traveling wave signal.

[0016] According to the present invention, an absolute time-grid angular displacement sensor based on a layer structure is provided, wherein the first excitation electrode has a first number of first excitation electrode groups, and the second excitation electrode has the first number of second excitation electrode groups;

[0017] The first excitation electrode is composed of a first excitation electrode piece arranged in a circle at equal intervals along the circumference, which is the product of the first number and the number of pole pairs of the first excitation electrode. Each adjacent first number of first excitation electrode pieces forms a first excitation pole pair. The first excitation electrode pieces at the same position in each first excitation pole pair are connected in series to form a first excitation electrode group.

[0018] The second excitation electrode is composed of a circle of second excitation electrode pieces arranged at equal intervals along the circumference, which is the product of the first number and the second number of pole pairs of the second excitation electrode. Each adjacent first number of second excitation electrode pieces forms a second excitation pole pair. The second excitation electrode pieces at the same position in each second excitation pole pair are connected in series to form a second excitation electrode group.

[0019] The first sensing electrode is composed of a circle of first sensing electrode pieces arranged at equal intervals along the circumference, which is the product of the first number and the third number of the first sensing electrode pairs. Each adjacent first number of first sensing electrode pieces forms a first sensing pair. The first sensing electrode pieces at the same position in each first sensing pair are connected in series to form a first sensing electrode group.

[0020] The second sensing electrode is composed of a circle of second sensing electrode pieces arranged at equal intervals along the circumference, which is the product of the first number and the fourth number of the second sensing electrode pairs. Each adjacent first number of second sensing electrode pieces forms a second sensing electrode pair. The second sensing electrode pieces at the same position in each second sensing electrode pair are connected in series to form a second sensing electrode group.

[0021] According to the present invention, an absolute time-grid angular displacement sensor based on a layer structure is provided, wherein the first reflective electrode is composed of a first number of first reflective electrodes arranged in a circle at equal intervals along the circumference, and each adjacent first number of first reflective electrodes forms a first reflective pair; the first reflective electrodes at the same position in each first reflective pair are connected in series to form a first reflective electrode group; the first reflective electrode group is connected to the first sensing electrode group in a one-to-one correspondence.

[0022] The second reflective electrode is composed of a second multiple of the first number of second reflective electrodes arranged in a circle at equal intervals along the circumference, and each adjacent first number of second reflective electrodes forms a second reflective pair; the second reflective electrodes at the same position in each second reflective pair are connected in series to form a second reflective electrode group; the second reflective electrode group is connected to the second sensing electrode group in a one-to-one correspondence.

[0023] According to the present invention, an absolute time-grid angular displacement sensor based on a layer structure is provided, wherein the first receiving electrode is composed of a second number of first receiving electrodes arranged in a circle with equal spacing along the circumference, and the second receiving electrode is composed of a third number of second receiving electrodes arranged in a circle with equal spacing along the circumference.

[0024] According to the present invention, an absolute time-grid angular displacement sensor based on a layer structure is provided, wherein the odd-numbered first receiving electrodes in the first receiving electrode are connected together as a group to serve as the output electrode of one first target traveling wave signal, and the even-numbered first receiving electrodes in the first receiving electrode are connected together as the output electrode of another first target traveling wave signal.

[0025] The odd-numbered second receiving electrodes in the second receiving electrode are connected together to form a group, serving as the output electrode of one second target traveling wave signal, and the even-numbered second receiving electrodes in the second receiving electrode are connected together to form a group, serving as the output electrode of another second target traveling wave signal.

[0026] According to the present invention, an absolute time-grid angular displacement sensor based on a layer structure is provided, wherein a first gap is provided between the first surface and the second surface, and a second gap is provided between the second surface and the fourth surface.

[0027] According to the present invention, an absolute time-grid angular displacement sensor based on a layer structure is provided, wherein the central angle between the starting points of the two identical cosine polar coordinate curve segments is less than the ratio of 180° to the number of poles of the receiving electrode.

[0028] The present invention provides an absolute time-grid angular displacement sensor based on a layered structure, comprising an excitation electrode layer distributed on the surface of a first stator substrate, a sensing electrode layer and a reflective electrode layer distributed on the surface of a rotor substrate, and a receiving electrode layer distributed on the surface of a second stator substrate. In operation, this improves the signal-to-noise ratio, increases signal strength, and reduces signal transmission interference, thereby enhancing the measurement accuracy and reliability of the angular displacement sensor. Furthermore, the introduction of the multi-layered structure increases the sensing area on each substrate, further improving the quality of the angular displacement sensor's output. The differential structure of the receiving electrodes improves measurement stability, suppresses common-mode interference, enhances signal amplitude, and strengthens industrial adaptability. In addition, the special shape of the receiving electrodes improves the linearity of the output, resulting in higher accuracy of the angular displacement sensor's output under this modulation principle. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on the drawings described below without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of the absolute time-grid angular displacement sensor based on a layer structure provided by the present invention;

[0031] Figure 2 This is a schematic diagram of the fourth surface of the second stator substrate in the absolute time-grid angular displacement sensor based on a layer structure provided by the present invention;

[0032] Figure 3 This is a schematic diagram of the first surface of the first stator substrate in the absolute time-grid angular displacement sensor based on a layer structure provided by the present invention;

[0033] Figure 4 This is a schematic diagram of the second surface of the rotor substrate in the absolute time-grid angular displacement sensor based on a layered structure provided by the present invention;

[0034] Figure 5 This is a schematic diagram of the third surface of the rotor substrate in the absolute time-grid angular displacement sensor based on a layered structure provided by the present invention;

[0035] Figure 6 This is a schematic diagram of the signal processing module in the layered absolute time-grid angular displacement sensor provided by the present invention;

[0036] Figure 7 This is a schematic diagram of the structure of the first sensing electrode group and the second sensing electrode group in the absolute time-grid angular displacement sensor based on a layer structure provided by the present invention;

[0037] Figure 8 This is a schematic diagram of the structure of the first reflective electrode group and the second reflective electrode group in the absolute time-grid angular displacement sensor based on a layer structure provided by the present invention. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0039] Because existing angular displacement sensors suffer from cumulative errors, or the installation of signal output lines is cumbersome, the signal output lines suffer severe wear under prolonged high-speed operation in industrial applications, leading to reduced sensor reliability. Therefore, this invention provides an absolute time-grid angular displacement sensor based on a layered structure.

[0040] Figure 1 This is a schematic diagram of the structure of an absolute time-grid angular displacement sensor based on a layer structure provided in an embodiment of the present invention, as shown below. Figure 1 As shown, the absolute time-grid angular displacement sensor includes: a first stator base 1, a rotor base 2, and a second stator base 3, which are coaxially and sequentially mounted.

[0041] An excitation electrode layer is distributed on the first surface of the first stator substrate 1 facing the rotor substrate 2, an induction electrode layer is distributed on the second surface of the rotor substrate 2 facing the first stator substrate 1, a reflection electrode layer is distributed on the third surface of the rotor substrate 2 facing the second stator substrate 3, and a receiving electrode layer is distributed on the fourth surface of the second stator substrate 3 facing the rotor substrate 2.

[0042] The excitation electrode on the excitation electrode layer, the induction electrode on the induction electrode layer, the reflection electrode on the reflection electrode layer, and the receiving electrode on the receiving electrode layer correspond one-to-one. The receiving electrode is a differential structure. The shape of the receiving electrode is a fully enclosed figure formed by two identical cosine polar coordinate curve segments in the interval [-π, 0] intersecting with concentric inner and outer circular arcs at the starting and ending points.

[0043] Specifically, in the layered absolute time-grid angular displacement sensor provided in this embodiment of the invention, the first stator base 1, the rotor base 2, and the second stator base 3 are coaxially and sequentially installed, and there is a certain gap between the first stator base 1, the rotor base 2, and the second stator base 3 to ensure that the rotor base 2 can rotate normally.

[0044] An excitation electrode layer is distributed on the first surface of the first stator substrate 1 facing the rotor substrate 2. The excitation electrode layer may include one or more excitation electrodes, and each excitation electrode may be provided with one or more excitation electrode plates. Figure 1 In this context, the first surface is the lower surface of the first stator substrate 1.

[0045] A sensing electrode layer is distributed on the second surface of the rotor base 2 facing the first stator base 1. The sensing electrode layer may include one or more sensing electrodes, and each sensing electrode may be provided with one or more sensing electrode sheets. Figure 1 In the middle, the second surface is the upper surface of the rotor base 2.

[0046] A reflective electrode layer is distributed on the third surface of the rotor base 2 facing the second stator base 3. The reflective electrode layer may include one or more reflective electrodes, and each reflective electrode may be provided with one or more reflective electrode sheets. Figure 1 In the middle, the third surface is the lower surface of the rotor base 2.

[0047] A receiving electrode layer is distributed on the fourth surface of the second stator substrate 3 facing the rotor substrate 2. The receiving electrode layer may include one or more receiving electrodes, and each receiving electrode may be provided with one or more receiving electrode plates. Figure 1 In the middle, the fourth surface is the upper surface of the second stator substrate 3.

[0048] The excitation electrode on the excitation electrode layer, the induction electrode on the induction electrode layer, the reflection electrode on the reflection electrode layer, and the receiving electrode on the receiving electrode layer correspond one-to-one.

[0049] like Figure 2 As shown, the receiving electrode on the fourth surface of the second stator substrate 3 is a differential structure. The receiving electrode may include a first receiving electrode 31 and a second receiving electrode 32. The shape of the receiving electrode can be a fully enclosed figure formed by the intersection of two identical cosine polar coordinate curve segments in the interval [-π, 0] with concentric inner and outer circular arcs at their starting and ending points. That is, the shape of the receiving electrode can be fan-shaped, and all receiving electrodes are identical. The receiving electrodes can be formed by arranging the receiving electrodes with equal arc lengths along the circumferential direction. The central angle between the starting points of the two identical cosine polar coordinate curve segments can be set as needed, for example, it can be set to 44.56°, 59.12°, etc., without specific limitation here. Figure 2 Each receiving electrode contains two receiving plates.

[0050] In this embodiment of the invention, the excitation electrode, sensing electrode, reflecting electrode, and receiving electrode can all operate simultaneously (i.e., all excitation electrodes, all sensing electrodes, all reflecting electrodes, and all receiving electrodes operate at the same time), or they can be selected to operate separately; no specific limitation is made here. Here, the excitation electrode is used to receive the excitation signal of the target number of paths; the sensing electrode is used to couple with the excitation electrode to obtain the initial traveling wave signal of the target number of paths, and transmits the initial traveling wave signal to the reflecting electrode; the reflecting electrode is used to couple the initial traveling wave signal to the receiving electrode; and the receiving electrode is used to output the target traveling wave signal. Subsequently, the target traveling wave signal can be processed by other modules included in the absolute time-grid angular displacement sensor to obtain and output the measurement result of the absolute time-grid angular displacement sensor, i.e., the absolute angular displacement value.

[0051] The absolute time-grid angular displacement sensor based on a layered structure provided in this embodiment of the invention includes an excitation electrode layer distributed on the surface of a first stator substrate, a sensing electrode layer and a reflective electrode layer distributed on the surface of a rotor substrate, and a receiving electrode layer distributed on the surface of a second stator substrate. In operation, this improves the signal-to-noise ratio, increases signal strength, and reduces signal transmission interference, thereby enhancing the measurement accuracy and reliability of the angular displacement sensor. Furthermore, the introduction of the multi-layered structure increases the sensing area on each substrate, further improving the quality of the angular displacement sensor's output. The differential structure of the receiving electrodes improves measurement stability, suppresses common-mode interference, enhances signal amplitude, and strengthens industrial adaptability. In addition, the special shape of the receiving electrodes improves the linearity of the output, resulting in higher accuracy of the angular displacement sensor's output under this modulation principle.

[0052] Based on the above embodiments, the absolute time-grid angular displacement sensor based on a layer structure provided in this embodiment of the invention includes an excitation electrode comprising a first excitation electrode and a second excitation electrode, a sensing electrode comprising a first sensing electrode and a second sensing electrode, a reflection electrode comprising a first reflection electrode and a second reflection electrode, and a receiving electrode comprising a first receiving electrode and a second receiving electrode. The first excitation electrode, the first sensing electrode, the first reflection electrode, and the first receiving electrode correspond to each other, as do the second excitation electrode, the second sensing electrode, the second reflection electrode, and the second receiving electrode.

[0053] Both the first excitation electrode and the second excitation electrode are used to receive the excitation signal of the target number of channels;

[0054] The first sensing electrode and the second sensing electrode are respectively used to couple with the first excitation electrode and the second excitation electrode, and respectively obtain the initial traveling wave signal of the target number of paths, and respectively transmit the initial traveling wave signal to the first reflecting electrode and the second reflecting electrode;

[0055] The first reflective electrode and the second reflective electrode are used to couple the initial traveling wave signal to the first receiving electrode and the second receiving electrode, respectively;

[0056] The first receiving electrode and the second receiving electrode are used to output two channels of first target traveling wave signal and second target traveling wave signal, respectively.

[0057] Specifically, in the embodiments of the present invention, such as Figure 3 As shown, the excitation electrodes on the first surface of the first stator substrate 1 may include two electrodes, namely a first excitation electrode 11 and a second excitation electrode 12; correspondingly, as Figure 4As shown, the second surface of the rotor base 2 also includes two sensing electrodes, namely a first sensing electrode 21 and a second sensing electrode 22; as Figure 5 As shown, the third surface of the rotor base 2 also includes two reflective electrodes, namely a first reflective electrode 23 and a second reflective electrode 24. Figure 2 As shown, the receiving electrode on the fourth surface of the second stator substrate 3 also includes two electrodes, namely the first receiving electrode 31 and the second receiving electrode 32.

[0058] The first excitation electrode 11, the first sensing electrode 21, the first reflecting electrode 23, and the first receiving electrode 31 are corresponding to each other, i.e., directly opposite each other, and are all located in the outer annular region of the corresponding substrate surface. The corresponding first excitation electrode 11, first sensing electrode 21, first reflecting electrode 23, and first receiving electrode 31 can form a first working unit.

[0059] The second excitation electrode 12, the second sensing electrode 22, the second reflecting electrode 24, and the second receiving electrode 32 are corresponding to each other, i.e., directly opposite each other, and are all located in the inner annular region of the corresponding substrate surface. The corresponding second excitation electrode 12, second sensing electrode 22, second reflecting electrode 24, and second receiving electrode 32 can form a second working unit. Here, the first working unit and the second working unit are independent of each other; they can operate simultaneously or at different times.

[0060] Both the first excitation electrode 11 and the second excitation electrode 12 can receive the target number of excitation signals. The target number of signals can be equal to the number of excitation electrode groups on the first excitation electrode 11 and the second excitation electrode 12. Here, the number of excitation electrode groups is the number of wires that can be connected to each excitation electrode on the first excitation electrode 11 and the second excitation electrode 12.

[0061] The excitation signal can be a sinusoidal excitation signal, and each excitation signal can have the same frequency and amplitude, and can be sequentially separated by a preset phase. For example, if the target number of channels is 4, the preset phase can be 90°.

[0062] The first sensing electrode 21 is coupled to the first excitation electrode 11 to obtain a first initial traveling wave signal for the target number of paths, and the obtained first initial traveling wave signal is transmitted to the first reflecting electrode 23. The second sensing electrode 22 is coupled to the second excitation electrode 12 to obtain a second initial traveling wave signal for the target number of paths, and the obtained second initial traveling wave signal is transmitted to the second reflecting electrode 24.

[0063] Here, the first initial traveling wave signal and the second initial traveling wave signal are different because the first sensing electrode 21 and the second sensing electrode 22 are located on the sensing electrode layer.

[0064] The first reflecting electrode 23 couples the first initial traveling wave signal to the first receiving electrode 31, which then outputs two channels of the first target traveling wave signal. The phase difference between the two channels of the first target traveling wave signal can be 180°. Similarly, the second reflecting electrode 24 couples the second initial traveling wave signal to the second receiving electrode 32, which then outputs two channels of the second target traveling wave signal. The phase difference between the two channels of the second target traveling wave signal can also be 180°.

[0065] In this embodiment of the invention, by having two independent working units work simultaneously with the second working unit, and synchronously outputting two target traveling wave signals, the time difference between the output of the first target traveling wave signal and the second target traveling wave signal can be reduced, which is beneficial to improving the accuracy and precision of the measurement results of the subsequently determined absolute time-grid angular displacement sensor.

[0066] Based on the above embodiments, the absolute time-grid angular displacement sensor based on a layer structure provided in this embodiment of the invention further includes a signal processing module, which is connected to the first receiving electrode and the second receiving electrode respectively.

[0067] The signal processing module is used to receive the first target traveling wave signal and the second target traveling wave signal, determine the first differential traveling wave signal corresponding to the first target traveling wave signal and the second differential traveling wave signal corresponding to the second target traveling wave signal, and determine and output the absolute angular displacement value based on the first differential traveling wave signal and the second differential traveling wave signal.

[0068] Specifically, in this embodiment of the invention, the signal processing module can be connected to the first receiving electrode 31 and the second receiving electrode 32, respectively. For example... Figure 6 As shown, the signal processing module may include a first subtraction circuit, a second subtraction circuit, a shaping circuit, and a signal processing unit. The first subtraction circuit is connected to the first receiving electrode, the second subtraction circuit is connected to the second receiving electrode, and both the first and second subtraction circuits are connected to the shaping circuit, which is connected to the signal processing unit.

[0069] The first subtraction circuit can be used to receive two first target traveling wave signals and perform subtraction on the first target traveling wave signals to obtain the first differential traveling wave signal U. 01 Among them, U 01 =K e U m *sin[ωt+15θ],K e U is the electric field coupling coefficient. m The amplitude of the excitation signal can be taken as 5V, ω is the angular frequency of the excitation signal, ω=2πf, f is the frequency of the excitation signal, which can be taken as 40KHz, and thus the angular frequency ω=8×104 π. θ is the precisely measured angular displacement value.

[0070] The second subtraction circuit can have the same structure as the first subtraction circuit. It can be used to receive two second target traveling wave signals and perform subtraction on the second target traveling wave signals to obtain the second differential traveling wave signal U. 02 Among them, U 02 =K e U m *sin[ωt+16θ].

[0071] Both the first and second differential traveling wave signals are sine waves. When the signal processing module determines and outputs the absolute angular displacement value based on the first and second differential traveling wave signals, it can use a shaping circuit to shape the first and second differential traveling wave signals from sine waves into square waves, and then input both the square wave first and second differential traveling wave signals to the signal processing unit.

[0072] The signal processing unit can perform precision measurement using the first differential traveling wave signal of a square wave, that is, it can combine the first differential traveling wave signal of the square wave with a reference signal U shaped into a square wave with a fixed phase. r A phase comparison is performed, and the phase difference after the comparison is represented by the number of interpolated high-frequency clock pulses. After transformation, the precise angular displacement value is obtained.

[0073] On the other hand, the signal processing unit can achieve the coarse measurement part through the second differential traveling wave signal of the square wave, that is, it can compare the second differential traveling wave signal of the square wave with the reference signal U at the same frequency. r A phase comparison is performed, and the phase difference after the comparison is represented by the number of interpolated high-frequency clock pulses. After transformation, the coarse measurement pole position value is obtained.

[0074] By combining the phase relationship between the first differential traveling wave signal and the second differential traveling wave signal of the sine wave, the absolute angular displacement value can be obtained, which is the output result of the absolute grating angular displacement sensor.

[0075] It is understandable that a sinusoidal reference signal U can be used. r The square wave reference signal U is obtained by shaping through a shaping circuit. r This signal is then input to the signal processing unit to compare its phase with the first differential traveling wave signal and the second differential traveling wave signal of the square wave. The signal processing unit can be a Field Programmable Gate Array (FPGA) chip signal processing system.

[0076] In this embodiment of the invention, both the coarse measurement of the polar position value and the fine measurement of the angular displacement value are achieved using the first differential traveling wave signal and the second differential traveling wave signal. The signal differences are small, which realizes both absolute measurement and ensures measurement accuracy.

[0077] Based on the above embodiments, the absolute time-grid angular displacement sensor based on a layer structure provided in the embodiments of the present invention has a first excitation electrode having a first number of first excitation electrode groups and a second excitation electrode having a first number of second excitation electrode groups.

[0078] The first excitation electrode is composed of a first excitation electrode piece arranged in a circle at equal intervals along the circumference, which is the product of the first number and the number of pole pairs of the first excitation electrode. Each adjacent first number of first excitation electrode pieces forms a first excitation pole pair. The first excitation electrode pieces at the same position in each first excitation pole pair are connected in series to form a first excitation electrode group.

[0079] The second excitation electrode is composed of a circle of second excitation electrode pieces arranged at equal intervals along the circumference, which is the product of the first number and the second number of pole pairs of the second excitation electrode. Each adjacent first number of second excitation electrode pieces forms a second excitation pole pair. The second excitation electrode pieces at the same position in each second excitation pole pair are connected in series to form a second excitation electrode group.

[0080] The first sensing electrode is composed of a circle of first sensing electrode pieces arranged at equal intervals along the circumference, which is the product of the first number and the third number of the first sensing electrode pairs. Each adjacent first number of first sensing electrode pieces forms a first sensing pair. The first sensing electrode pieces at the same position in each first sensing pair are connected in series to form a first sensing electrode group.

[0081] The second sensing electrode is composed of a circle of second sensing electrode pieces arranged at equal intervals along the circumference, which is the product of the first number and the fourth number of the second sensing electrode pairs. Each adjacent first number of second sensing electrode pieces forms a second sensing electrode pair. The second sensing electrode pieces at the same position in each second sensing electrode pair are connected in series to form a second sensing electrode group.

[0082] Specifically, in this embodiment of the invention, the first excitation electrode 11 has a first number A first excitation electrode groups, and the second excitation electrode 12 has a first number A second excitation electrode groups. A can be set as needed, for example, it can be set to 4.

[0083] The first excitation electrode 11 consists of A*M1 identical first excitation electrode pieces arranged in a circumferentially at equal intervals. Each first excitation electrode piece can be a fan-shaped annular electrode piece with an inner radius of 33 mm, a radial height of 9 mm, and a central angle of 2.8125°. The central angle corresponding to the interval between two adjacent first excitation electrodes is 2.8125°.

[0084] Each pair of adjacent A first excitation electrodes forms a first excitation pair, and M1 is the number of first excitation pairs. M1 can be 16, or it can be set as needed.

[0085] In each first excitation electrode pair, the first excitation electrodes at the same position are connected in series to form a first excitation electrode group, and the number of first excitation electrode groups is A. The excitation signal connection lines used to form the first excitation electrode groups are all loop conductors located on the same wiring layer. Here, each first excitation electrode has a wire hole for the excitation signal connection line to pass through and achieve series connection. The positions of the wire holes on the first excitation electrodes in each first excitation electrode pair are different to ensure that the excitation signal connection lines of different first excitation electrode groups do not interfere with each other.

[0086] For example, if A = 4 and M1 = 16, then the 4n1+1th first excitation electrode is connected to a group via the first excitation signal connection line, forming the first excitation electrode group G11; the 4n1+2th first excitation electrode is connected to a group via the second excitation signal connection line, forming the first excitation electrode group G12; the 4n1+3th first excitation electrode is connected to a group via the third excitation signal connection line, forming the first excitation electrode group G13; and the 4n1+4th first excitation electrode is connected to a group via the fourth excitation signal connection line, forming the first excitation electrode group G14. The first, second, third, and fourth excitation signal connection lines are all loop conductors located on the same wiring layer, and n1 takes all integer values ​​from 0 to M1-1.

[0087] The second excitation electrode 12 consists of A*M2 identical second excitation electrode pieces arranged in a circumferentially at equal intervals. Each second excitation electrode piece can be a fan-shaped annular electrode piece with an inner radius of 21 mm, a radial height of 9 mm, and a central angle of 3°. The central angle between two adjacent second excitation electrode pieces is 3°. Here, M2 and M1 are coprime numbers.

[0088] Each pair of adjacent A second excitation electrodes forms a second excitation pair, and M2 is the number of second excitation pairs. M2 can be 15, or it can be set as needed.

[0089] In each second excitation electrode pair, the second excitation electrodes at the same position are connected in series to form a second excitation electrode group. The number of second excitation electrode groups is also A. All excitation signal connection lines used to form the second excitation electrode groups are loop conductors located on the same wiring layer. Here, each second excitation electrode has a wire hole for the excitation signal connection line to pass through and achieve series connection. The positions of the wire holes on the second excitation electrodes in each second excitation electrode pair are different to ensure that the excitation signal connection lines of different second excitation electrode groups do not interfere with each other.

[0090] For example, if A = 4 and M2 = 15, then the 4n2+1th second excitation electrode is connected to a group via the fifth excitation signal connection line, forming the second excitation electrode group G15; the 4n2+2th second excitation electrode is connected to a group via the sixth excitation signal connection line, forming the second excitation electrode group G16; the 4n2+3th second excitation electrode is connected to a group via the seventh excitation signal connection line, forming the second excitation electrode group G17; and the 4n2+4th second excitation electrode is connected to a group via the eighth excitation signal connection line, forming the second excitation electrode group G18. The fifth, sixth, seventh, and eighth excitation signal connection lines are all loop conductors located on the same wiring layer. n2 takes all integers from 0 to M2-1.

[0091] The first sensing electrode 21 and the second sensing electrode 22 also each have a first number A probes. The first sensing electrode 21 is composed of A*M3 first sensing electrode pieces arranged in a circle at equal intervals along the circumference. Each adjacent A first sensing electrode pieces form a first sensing pair, and M3 is the number of first sensing pairs, that is, the number of pairs of the first sensing electrode.

[0092] The shapes of the first sensing electrodes are all in polar coordinates. range or A closed figure I, or oblique cosine shape, is formed by the intersection of two identical half-period cosine curves at their starting and ending points on concentric inner and outer circular arcs. The central angle between the starting points of the two identical half-period cosine curve segments, i.e., the central angle subtended by the inner circular arc, is... For example, when M3 = 16, The central angle subtended by the inner arc is 2.8125°, the radius of the inner arc is 33.5 mm, the radius of the outer arc is 41.5 mm, and the radial height of each first induction electrode is 8 mm.

[0093] In each first sensing electrode pair, the first sensing electrodes at the same position are connected in series to form a first sensing electrode group, and the number of first sensing electrode groups is A. The sensing signal connection lines used to form the first sensing electrode groups are all loop conductors located on the same wiring layer. Here, each first sensing electrode has a wire hole for the sensing signal connection line to pass through and achieve series connection. The positions of the wire holes on the first sensing electrodes in each first sensing electrode pair are different to ensure that the sensing signal connection lines of different first sensing electrode groups do not interfere with each other.

[0094] like Figure 7 As shown, A = 4, M3 = 16. The 4n3+1th first sensing electrode is connected to a group via the first sensing signal connection line, forming the first sensing electrode group G21. The 4n3+2th first sensing electrode is connected to a group via the second sensing signal connection line, forming the first sensing electrode group G22. The 4n3+3th first sensing electrode is connected to a group via the third sensing signal connection line, forming the first sensing electrode group G23. The 4n3+4th first sensing electrode is connected to a group via the fourth sensing signal connection line, forming the first sensing electrode group G24. The first, second, third, and fourth sensing signal connection lines are all loop conductors located on the same wiring layer. Here, n3 takes all integers from 0 to M3-1.

[0095] The second sensing electrode 22 consists of A*M four second sensing electrode pieces arranged in a circle at equal intervals along the circumference. The shape of the second sensing electrode pieces is as shown in polar coordinates. range or The closed figure II, i.e., the oblique cosine shape, is formed by the intersection of two identical half-period cosine curves at their starting and ending points with concentric inner and outer circular arcs. The central angle corresponding to the interval between two adjacent second induction electrodes, i.e., the central angle subtended by the inner circular arc, is... For example, if A = 4 and M4 = 15, then The central angle subtended by the inner arc is 3°, the radius of the inner arc is 21.5 mm, the radius of the outer arc is 29.5 mm, and the radial height of each second induction electrode is 8 mm.

[0096] Each pair of A adjacent second sensing electrodes forms a second sensing pair, and the number of second sensing pairs, i.e., the number of pairs of second sensing electrodes, is M4. Second sensing electrodes at the same position within each second sensing pair are connected in series to form a second sensing electrode group, and the number of second sensing electrode groups is A. All sensing signal connection lines used to form the second sensing electrode groups are loop conductors located on the same wiring layer. Each second sensing electrode has a wire hole for the sensing signal connection line to pass through and achieve series connection. The positions of the wire holes on the second sensing electrodes within each second sensing pair are different to ensure that the sensing signal connection lines of different second sensing electrode groups do not interfere with each other.

[0097] The 4n4+1th second sensing electrodes are connected in a clockwise direction along the circumference to form a group of second sensing electrodes G25 via the fifth sensing signal connection line; the 4n4+2nd second sensing electrodes are connected to form a group of second sensing electrodes G26 via the sixth sensing signal connection line; the 4n4+3rd second sensing electrodes are connected to form a group of second sensing electrodes G27 via the seventh sensing signal connection line; and the 4n4+4th second sensing electrodes are connected to form a group of second sensing electrodes G28 via the eighth sensing signal connection line. The fifth, sixth, seventh, and eighth sensing signal connection lines are all loop conductors located on the same wiring layer. Here, n4 takes all integers from 0 to M4-1.

[0098] Based on the above embodiments, the absolute time-grid angular displacement sensor based on a layer structure provided in this embodiment of the invention comprises a first reflective electrode consisting of a first multiple of the first number of first reflective electrodes arranged in a circle at equal intervals along the circumference, with each adjacent first number of first reflective electrodes forming a first reflective pair; the first reflective electrodes at the same position in each first reflective pair are connected in series to form a first reflective electrode group; the first reflective electrode group is connected one-to-one with the first sensing electrode group.

[0099] The second reflective electrode is composed of a second multiple of the first number of second reflective electrodes arranged in a circle at equal intervals along the circumference, and each adjacent first number of second reflective electrodes forms a second reflective pair; the second reflective electrodes at the same position in each second reflective pair are connected in series to form a second reflective electrode group; the second reflective electrode group is connected to the second sensing electrode group in a one-to-one correspondence.

[0100] Specifically, in this embodiment of the invention, the first reflective electrode 23 is composed of A*K1 first reflective electrodes arranged in a circle at equal intervals along the circumference. The shape of the first reflective electrodes can be a fan-shaped annular electrode with an inner radius of 27mm, a radial height of 9mm, and a central angle of 75°. The central angle corresponding to the interval between two adjacent first reflective electrodes is 15°. Each pair of A adjacent first reflective electrodes forms a first reflective pair, and K1 is a first multiple.

[0101] The first reflective electrodes at the same position in each first reflective electrode pair are connected in series to form a first reflective electrode group. That is, the A*K1+1th first reflective electrode will be connected in series through the reflective signal connection line to form a first reflective electrode group.

[0102] For example, such as Figure 8 As shown, with A=4 and K1=1, a total of one first reflective electrode group can be formed, namely G31, G32, G33, and G34. The first reflective electrode group is connected to the first inductive electrode group in a one-to-one correspondence, that is, G31 is connected to G21, G32 is connected to G22, G33 is connected to G23, and G34 is connected to G24.

[0103] The second reflective electrode 24 consists of A*K2 second reflective electrodes arranged in a circumferentially at equal intervals. The shape of the second reflective electrodes can be a fan-shaped annular electrode with an inner radius of 17mm, a radial height of 9mm, and a central angle of 3°. The central angle corresponding to the interval between two adjacent second reflective electrodes is 3°. Each pair of adjacent A second reflective electrodes forms a second reflective electrode pair, and K2 is a multiple of the second reflective electrode.

[0104] The second reflective electrodes at the same position in each second reflective electrode pair are connected in series to form a second reflective electrode group. That is, the A*K2+1th second reflective electrode will be connected in series through the reflective signal connection line to form a second reflective electrode group.

[0105] For example, if A = 4 and K2 = 1, then four second reflective electrode groups can be formed, namely G35, G36, G37, and G38. The second reflective electrode groups are connected to the second inductive electrode groups in a one-to-one correspondence, that is, G35 is connected to G25, G36 is connected to G26, G37 is connected to G27, and G38 is connected to G28.

[0106] When the absolute time-grid angular displacement sensor performs measurement, the rotor base 2 rotates parallel to the first stator base 1 and the second stator base 3. Four sinusoidal excitation signals with the same frequency and amplitude, with a phase difference of 90°, are simultaneously applied to the first excitation electrode group G11, G12, G13, G14 and the second excitation electrode group G15, G16, G17, G18. The initial traveling wave signals coupled to the first and second induction electrodes are transmitted to the first and second reflection electrodes, respectively. Then, through the coupled electric field between the first reflection electrode and the first receiving electrode and the coupled electric field between the second reflection electrode and the second receiving electrode, two first target traveling wave signals with the same frequency and amplitude, with a phase difference of 180°, are output on the first receiving electrode, and two second target traveling wave signals with the same frequency and amplitude, with a phase difference of 180°, are output on the second receiving electrode.

[0107] Based on the above embodiments, the absolute time-grid angular displacement sensor based on a layer structure provided in this embodiment of the invention comprises a first receiving electrode consisting of a second number of first receiving electrodes arranged in a circle with equal spacing along the circumference, and a second receiving electrode consisting of a third number of second receiving electrodes arranged in a circle with equal spacing along the circumference.

[0108] Specifically, in this embodiment of the invention, the first receiving electrode 31 is composed of a second number of first receiving electrodes arranged in a circle at equal intervals along the circumference, and the second receiving electrode 32 is composed of a third number of second receiving electrodes arranged in a circle at equal intervals along the circumference. Both the second and third numbers can be set as needed, for example, they can be set to even numbers such as 2, 4, or 6; no specific limitation is made here. Figure 2 The example only provides the case where both the second and third quantities are 2.

[0109] Based on the above embodiments, the absolute time-grid angle displacement sensor based on layer structure provided in this embodiment of the invention has the odd-numbered first receiving electrodes in the first receiving electrode connected together as a group, serving as the output electrode of one first target traveling wave signal, and the even-numbered first receiving electrodes in the first receiving electrode connected together as the output electrode of another first target traveling wave signal.

[0110] The odd-numbered second receiving electrodes in the second receiving electrode are connected together to form a group, serving as the output electrode of one second target traveling wave signal, and the even-numbered second receiving electrodes in the second receiving electrode are connected together to form a group, serving as the output electrode of another second target traveling wave signal.

[0111] Specifically, in this embodiment of the invention, the 2n5+1th first receiving electrode in the first receiving electrode is connected as a group to serve as the output electrode of one first target traveling wave signal, and the 2n5+2th first receiving electrode in the first receiving electrode is connected as a group to serve as the output electrode of another first target traveling wave signal. n5 takes all integers from 0 to M5-1 in sequence, and M5 represents the number of poles of the first receiving electrode, which can be 1.

[0112] The 2n6+1th second receiving electrode in the second receiving electrode is connected as a group, serving as the output electrode of one second target traveling wave signal. The 2n6+2th second receiving electrode in the second receiving electrode is connected as a group, serving as the output electrode of another second target traveling wave signal. n6 takes all integers from 0 to M6-1 in sequence, and M6 represents the number of pairs of the second receiving electrode.

[0113] Based on the above embodiments, the absolute time-grid angular displacement sensor based on a layer structure provided in this embodiment of the invention has a first gap between the first surface and the second surface, and a second gap between the second surface and the fourth surface.

[0114] Specifically, in this embodiment of the invention, both the first gap and the second gap can be 0.5mm, which ensures that the rotor base rotates relative to the first stator base and the second stator base.

[0115] Based on the above embodiments, the absolute time-grid angular displacement sensor based on a layer structure provided in this embodiment of the invention has a central angle between the starting points of the two identical cosine polar coordinate curve segments that is less than the ratio of 180° to the number of poles of the receiving electrode.

[0116] Specifically, in this embodiment of the invention, the central angle α between the starting points of the two identical cosine polar coordinate curve segments of the first receiving electrode is less than 180 / M5, where M5 is the number of poles of the first receiving electrode. The central angle β between the starting points of the two identical cosine polar coordinate curve segments of the second receiving electrode is less than 180 / M6, where M6 is the number of poles of the second receiving electrode. Here, it is sufficient that α is slightly less than 180 / M5 and β is slightly less than 180 / M6.

[0117] Based on the above embodiments, the absolute time-grid angular displacement sensor based on a layer structure provided in this embodiment of the invention uses ceramic materials for the first stator substrate, the rotor substrate, and the second stator substrate, and uses iron-nickel alloy materials for the electrode plates of the excitation electrode, the sensing electrode, the reflecting electrode, and the receiving electrode.

[0118] In summary, the absolute time-grid angular displacement sensor based on a layered structure provided in this embodiment of the invention has the following advantages:

[0119] (1) By setting the excitation electrode layer and the receiving electrode layer on the first surface of the first stator substrate and the fourth surface of the second stator substrate, respectively, the interference of the excitation signal on the output displacement signal is reduced in the working state of the absolute grid angle displacement sensor, thereby improving the quality and reliability of the output displacement signal.

[0120] (2) The multi-layer structure increases the sensing area on each substrate surface, thereby improving the quality of the output results of the absolute time grating displacement sensor.

[0121] (3) The four traveling wave signals sensed by the first sensing electrode and the second sensing electrode are used as the excitation signals for secondary coupling modulation. The excitation signals for secondary coupling modulation are modulated by the reflective electrode and the receiving electrode. The rotor base does not need to lead a signal output line, which improves the reliability of the sensor and has a wider range of applications.

[0122] (4) The first receiving electrode and the second receiving electrode simultaneously output two channels of first target traveling wave signal and second target traveling wave signal, which reduces signal output error and improves measurement accuracy.

[0123] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0124] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0125] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An absolute time-grid angular displacement sensor based on a layered structure, characterized in that, include: The first stator base, the rotor base, and the second stator base are coaxially and sequentially installed. An excitation electrode layer is distributed on the first surface of the first stator substrate facing the rotor substrate; an induction electrode layer is distributed on the second surface of the rotor substrate facing the first stator substrate; a reflection electrode layer is distributed on the third surface of the rotor substrate facing the second stator substrate; and a receiving electrode layer is distributed on the fourth surface of the second stator substrate facing the rotor substrate. The excitation electrode on the excitation electrode layer, the induction electrode on the induction electrode layer, the reflection electrode on the reflection electrode layer, and the receiving electrode on the receiving electrode layer correspond one-to-one. The receiving electrode is a differential structure. The shape of the receiving electrode is a fully enclosed figure formed by two identical cosine polar coordinate curve segments in the interval [-π, 0] intersecting with concentric inner and outer circular arcs at the starting and ending points. The excitation electrode includes a first excitation electrode and a second excitation electrode; the sensing electrode includes a first sensing electrode and a second sensing electrode; the reflection electrode includes a first reflection electrode and a second reflection electrode; and the receiving electrode includes a first receiving electrode and a second receiving electrode. The first excitation electrode, the first sensing electrode, the first reflection electrode, and the first receiving electrode correspond to each other, and the second excitation electrode, the second sensing electrode, the second reflection electrode, and the second receiving electrode correspond to each other. Both the first excitation electrode and the second excitation electrode are used to receive the excitation signal of the target number of channels; The first sensing electrode and the second sensing electrode are respectively used to couple with the first excitation electrode and the second excitation electrode, and respectively obtain the initial traveling wave signal of the target number of paths, and respectively transmit the initial traveling wave signal to the first reflecting electrode and the second reflecting electrode; The first reflective electrode and the second reflective electrode are used to couple the initial traveling wave signal to the first receiving electrode and the second receiving electrode, respectively; The first receiving electrode and the second receiving electrode are used to output two channels of first target traveling wave signal and second target traveling wave signal, respectively.

2. The absolute time-grid angular displacement sensor based on a layered structure according to claim 1, characterized in that, It also includes a signal processing module, which is connected to the first receiving electrode and the second receiving electrode respectively; The signal processing module is used to receive the first target traveling wave signal and the second target traveling wave signal, determine the first differential traveling wave signal corresponding to the first target traveling wave signal and the second differential traveling wave signal corresponding to the second target traveling wave signal, and determine and output the absolute angular displacement value based on the first differential traveling wave signal and the second differential traveling wave signal.

3. The absolute time-grid angular displacement sensor based on a layered structure according to claim 1, characterized in that, The first excitation electrode has a first number of first excitation electrode groups, and the second excitation electrode has the first number of second excitation electrode groups; The first excitation electrode is composed of a first excitation electrode piece arranged in a circle at equal intervals along the circumference, which is the product of the first number and the number of pole pairs of the first excitation electrode. Each adjacent first number of first excitation electrode pieces forms a first excitation pole pair. The first excitation electrode pieces at the same position in each first excitation pole pair are connected in series to form a first excitation electrode group. The second excitation electrode is composed of a circle of second excitation electrode pieces arranged at equal intervals along the circumference, which is the product of the first number and the second number of pole pairs of the second excitation electrode. Each adjacent first number of second excitation electrode pieces forms a second excitation pole pair. The second excitation electrode pieces at the same position in each second excitation pole pair are connected in series to form a second excitation electrode group. The first sensing electrode is composed of a circle of first sensing electrode pieces arranged at equal intervals along the circumference, which is the product of the first number and the third number of the first sensing electrode pairs. Each adjacent first number of first sensing electrode pieces forms a first sensing pair. The first sensing electrode pieces at the same position in each first sensing pair are connected in series to form a first sensing electrode group. The second sensing electrode is composed of a circle of second sensing electrode pieces arranged at equal intervals along the circumference, which is the product of the first number and the fourth number of the second sensing electrode pairs. Each adjacent first number of second sensing electrode pieces forms a second sensing electrode pair. The second sensing electrode pieces at the same position in each second sensing electrode pair are connected in series to form a second sensing electrode group.

4. The absolute time-grid angular displacement sensor based on a layered structure according to claim 3, characterized in that, The first reflective electrode is composed of a first number of first reflective electrodes arranged in a circle at equal intervals along the circumference, and each adjacent first number of first reflective electrodes forms a first reflective pair; the first reflective electrodes at the same position in each first reflective pair are connected in series to form a first reflective electrode group; the first reflective electrode group is connected to the first sensing electrode group in a one-to-one correspondence. The second reflective electrode is composed of a second multiple of the first number of second reflective electrodes arranged in a circle at equal intervals along the circumference, and each adjacent first number of second reflective electrodes forms a second reflective pair; the second reflective electrodes at the same position in each second reflective pair are connected in series to form a second reflective electrode group; the second reflective electrode group is connected to the second sensing electrode group in a one-to-one correspondence.

5. The absolute time-grid angular displacement sensor based on a layered structure according to claim 1, characterized in that, The first receiving electrode is composed of a second number of first receiving electrodes arranged in a circle with equal spacing along the circumference, and the second receiving electrode is composed of a third number of second receiving electrodes arranged in a circle with equal spacing along the circumference.

6. The absolute time-grid angular displacement sensor based on a layered structure according to claim 5, characterized in that, The odd-numbered first receiving electrodes in the first receiving electrode are connected together as a group to serve as the output electrode of one first target traveling wave signal, and the even-numbered first receiving electrodes in the first receiving electrode are connected together as the output electrode of another first target traveling wave signal. The odd-numbered second receiving electrodes in the second receiving electrode are connected together to form a group, serving as the output electrode of one second target traveling wave signal, and the even-numbered second receiving electrodes in the second receiving electrode are connected together to form a group, serving as the output electrode of another second target traveling wave signal.

7. The absolute time-grid angular displacement sensor based on a layered structure according to any one of claims 1-6, characterized in that, There is a first gap between the first surface and the second surface, and a second gap between the second surface and the fourth surface.

8. The absolute time-grid angular displacement sensor based on a layered structure according to any one of claims 1-6, characterized in that, The ratio of the central angle between the starting points of the two identical cosine polar coordinate curve segments to the number of opposite poles of the receiving electrode is less than 180°.

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