Absolute time grating angular displacement sensor based on combined modulation

Abstract

The application relates to the technical field of precise angular displacement sensors, and provides an absolute time grating angular displacement sensor based on combined modulation, which can improve the signal-to-noise ratio, increase signal strength, reduce signal transmission interference, improve the measurement accuracy and reliability of the angular displacement sensor in a working state. The introduction of the multilayer structure increases the sensing area on each base body, and improves the quality of the output result of the angular displacement sensor. The second receiving electrode is in a differential structure, can improve the measurement stability, suppress common-mode interference, enhance the signal amplitude, and has stronger industrial adaptability. Due to the special shape of the first receiving electrode and the second receiving electrode, the linearity of the output result can be improved, the output result accuracy of the angular displacement sensor determined by the first target traveling wave signal and the second target traveling wave signal obtained under respective modulation principles is higher.

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 combined modulation. 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 combined modulation to overcome the deficiencies in the prior art.

[0006] The present invention provides an absolute time-grid angular displacement sensor based on combined modulation, comprising: a first stator base, a rotor base, and a second stator base 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 layer includes a first excitation electrode and a second excitation electrode; the sensing electrode layer includes a first sensing electrode and a second sensing electrode; the reflective electrode layer includes a first reflective electrode and a second reflective electrode; and the receiving electrode layer includes a first receiving electrode and a second receiving electrode. The second receiving electrode has a differential structure. The first excitation electrode, the first sensing electrode, the first reflective electrode, and the first receiving electrode correspond to each other, as do the second excitation electrode, the second sensing electrode, the second reflective electrode, and the second receiving electrode.

[0009] The first receiving electrode includes a first receiving electrode plate, and the second receiving electrode includes a second receiving electrode plate. The first receiving electrode plate is circular in shape, and the second receiving electrode is a fully enclosed shape formed by two identical cosine polar coordinate curve segments in the interval [-π, 0] intersecting with concentric inner and outer circular arcs at their starting and ending points.

[0010] According to the present invention, an absolute time-grid angle displacement sensor based on combined modulation is provided, wherein both the first excitation electrode and the second excitation electrode are used to receive excitation signals of a target number of paths;

[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 the first target traveling wave signal and the second target traveling wave signal, respectively.

[0014] According to the present invention, an absolute time-grid angular displacement sensor based on combined modulation 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 includes a storage module, which is used to receive and store the second target traveling wave signal when the second excitation electrode is working.

[0016] The signal processing module is used to receive the first target traveling wave signal when the first excitation electrode is working, and to determine the four first traveling wave signals corresponding to the first target traveling wave signal and the two second traveling wave signals corresponding to the second target traveling wave signal respectively. Based on the four first traveling wave signals and the two second traveling wave signals, the absolute angular displacement value is determined and output through data fusion and signal processing.

[0017] According to the present invention, an absolute time-grid angular displacement sensor based on combined modulation is provided, wherein the first receiving electrode is composed of a first number of first receiving electrodes arranged in a circle at equal intervals along the circumference, and the second receiving electrode is composed of a second number of second receiving electrodes arranged at equal intervals along the radial direction.

[0018] According to the present invention, an absolute time-grid angular displacement sensor based on combined modulation is provided, wherein each first receiving electrode in the first receiving electrode serves as an output electrode for a first target traveling wave signal.

[0019] 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.

[0020] According to the present invention, an absolute time-grid angular displacement sensor based on combined modulation is provided, wherein the first excitation electrode has a third number of first excitation electrode groups, the second excitation electrode has the third number of second excitation electrode groups, the first sensing electrode has a fourth number of probes, and the second sensing electrode has a fifth number of probes.

[0021] The first excitation electrode is composed of a circle of first excitation electrode pieces arranged at equal intervals along the circumference, which is the product of the third number and the number of pole pairs of the first excitation electrode. Each adjacent third 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.

[0022] 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 third number and the number of pole pairs of the second excitation electrode. Each adjacent third 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.

[0023] 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 fourth number and the third number of the first sensing electrode pairs. Each adjacent fourth 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.

[0024] 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 fifth number and the fourth number of the second sensing electrode pairs. Each adjacent fifth number of second sensing electrode pieces forms a second sensing pair. The second sensing electrode pieces at the same position in each second sensing pair are connected in series to form a second sensing electrode group.

[0025] According to the present invention, an absolute time-grid angular displacement sensor based on combined modulation is provided, wherein the first reflective electrode is formed by the fourth number of first reflective plates arranged radially at equal intervals, and the first reflective plates are connected one-to-one with the first sensing electrode group.

[0026] The second reflective electrode is composed of a fifth number of second reflective electrodes arranged in a circle at equal intervals along the circumference, and the second reflective electrodes are connected one-to-one with the second inductive electrode group.

[0027] According to the present invention, an absolute time-grid angular displacement sensor based on combined modulation 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.

[0028] According to the present invention, an absolute time-grid angular displacement sensor based on combined modulation 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 opposite poles of the receiving electrode.

[0029] The absolute time-grating angular displacement sensor based on combined modulation provided by this invention can improve the signal-to-noise ratio, increase signal strength, and reduce signal transmission interference during operation, thereby improving the measurement accuracy and reliability of the angular displacement sensor. Furthermore, the introduction of a multi-layer structure increases the sensing area on each substrate, further improving the quality of the angular displacement sensor's output. The second receiving electrode has a differential structure, which can improve measurement stability, suppress common-mode interference, enhance signal amplitude, and enhance industrial adaptability. In addition, due to the special shapes of the first and second receiving electrodes, not only can the linearity of the output be improved, but the accuracy of the angular displacement sensor output determined by the first and second target traveling wave signals obtained through their respective modulation principles can also be higher. Attached Figure Description

[0030] 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.

[0031] Figure 1 This is a schematic diagram of the structure of the absolute time-grid angular displacement sensor based on combined modulation provided by the present invention;

[0032] Figure 2 This is a schematic diagram of the first surface of the first stator substrate in the absolute time-grid angular displacement sensor based on combined modulation provided by the present invention.

[0033] Figure 3 This is a schematic diagram of the second surface of the rotor substrate in the absolute time-grid angular displacement sensor based on combined modulation provided by the present invention;

[0034] Figure 4 This is a schematic diagram of the third surface of the rotor substrate in the absolute time-grid angular displacement sensor based on combined modulation provided by the present invention;

[0035] Figure 5 This is a schematic diagram of the fourth surface of the second stator substrate in the absolute time-grid angular displacement sensor based on combined modulation provided by the present invention;

[0036] Figure 6 This is a schematic diagram of the signal processing module in the absolute time-grid angular displacement sensor based on combined modulation provided by the present invention. Detailed Implementation

[0037] 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.

[0038] 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 combined modulation.

[0039] like 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.

[0040] 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.

[0041] like Figure 2 As shown, the excitation electrode layer includes a first excitation electrode 11 and a second excitation electrode 12, as follows: Figure 3 As shown, the sensing electrode layer includes a first sensing electrode 21 and a second sensing electrode 22, as... Figure 4 As shown, the reflective electrode layer includes a first reflective electrode 23 and a second reflective electrode 24, as... Figure 5 As shown, the receiving electrode layer includes a first receiving electrode 31 and a second receiving electrode 32.

[0042] The second receiving electrode 32 is a differential structure, with the first excitation electrode 11, the first sensing electrode 21, the first reflection electrode 23 and the first receiving electrode 31 corresponding to each other, and the second excitation electrode 21, the second sensing electrode 22, the second reflection electrode 24 and the second receiving electrode 32 corresponding to each other.

[0043] The first receiving electrode 31 includes a first receiving electrode plate, and the second receiving electrode 32 includes a second receiving electrode plate. The first receiving electrode plate is circular in shape, and the second receiving electrode plate is a fully enclosed shape formed by two identical cosine polar coordinate curve segments in the interval [-π, 0] intersecting with concentric inner and outer circular arcs at their starting and ending points.

[0044] Specifically, in the embodiment of the present invention, the absolute time-grid angular displacement sensor based on combined modulation has a first stator base 1, a rotor base 2, and a second stator base 3 installed coaxially and sequentially, with 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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 not, without specific limitations.

[0051] The first reflective electrode 23 includes a first reflective electrode plate, and the second reflective electrode 24 includes a second reflective electrode plate. The number of the first and second reflective electrodes plates can be set as needed, and no specific limitation is made here. The first reflective electrode plate is circular in shape, and the second reflective electrode 24 is fan-shaped.

[0052] The first receiving electrode 31 includes a first receiving electrode plate, and the second receiving electrode 32 includes a second receiving electrode plate. The number of the first receiving electrode plate and the number of the second receiving electrode plate can be set as needed, and no specific limitation is made here.

[0053] Each first receiving electrode is annular in shape, and each second receiving electrode is a fully enclosed shape 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. In other words, the shape of the second receiving electrode can be fan-shaped. The second receiving electrodes can be formed by arranging the second receiving electrodes at equal intervals along the circumference. The central angle between the starting points of the two identical cosine polar coordinate curve segments can be set as needed, for example, to 44.56°, 59.12°, etc., without specific limitations here.

[0054] Here, both the first and second excitation electrodes are used to receive the excitation signals of the target channel; both the first and second sensing electrodes are used to couple with the corresponding excitation electrodes to obtain the initial traveling wave signals of the target channel, and transmit the initial traveling wave signals to the reflecting electrodes respectively; both the first and second reflecting electrodes are used to couple the corresponding initial traveling wave signals to the corresponding receiving electrodes; the first receiving electrode is used to output the first target traveling wave signal, and the second receiving electrode is used to output the second target traveling wave signal. Subsequently, the first and second target traveling wave signals can be processed by other modules included in the absolute time-grid angular displacement sensor to obtain and output the measurement results of the absolute time-grid angular displacement sensor, i.e., the absolute angular displacement value.

[0055] The absolute time-grid angular displacement sensor based on combined modulation 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, it can improve the signal-to-noise ratio, increase signal strength, and reduce signal transmission interference, thereby improving the measurement accuracy and reliability of the angular displacement sensor. Furthermore, the introduction of the multi-layer structure increases the sensing area on each substrate, further improving the quality of the angular displacement sensor's output. The second receiving electrode has a differential structure, which can improve measurement stability, suppress common-mode interference, enhance signal amplitude, and enhance industrial adaptability. In addition, due to the special shapes of the first and second receiving electrodes, not only can the linearity of the output result be improved, but the accuracy of the angular displacement sensor output result determined by the first target traveling wave signal and the second target traveling wave signal obtained through their respective modulation principles can also be higher.

[0056] Based on the above embodiments, the absolute time-grid angle displacement sensor based on combined modulation provided in the embodiments of the present invention is provided in which both the first excitation electrode and the second excitation electrode are used to receive the excitation signal of the target number of paths.

[0057] 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;

[0058] 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;

[0059] The first receiving electrode and the second receiving electrode are used to output the first target traveling wave signal and the second target traveling wave signal, respectively.

[0060] Specifically, in this embodiment of the invention, both the first excitation electrode 11 and the second excitation electrode 12 can receive a 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, for example, it can be any number greater than 2. Here, the first excitation electrode group on the first excitation electrode 11 is the number of wires that can be connected to each excitation electrode on the first excitation electrode 11, and the second excitation electrode group on the second excitation electrode 12 is the number of wires that can be connected to each excitation electrode on 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 four first target traveling wave signals. The phase difference between the four first target traveling wave signals can be 90°. Similarly, the second reflecting electrode 24 couples the second initial traveling wave signal to the second receiving electrode 32, which then outputs two second target traveling wave signals. The phase difference between the two second target traveling wave signals can be 180°.

[0065] Based on the above embodiments, the absolute time-grid angular displacement sensor based on combined modulation 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.

[0066] The signal processing module includes a storage module, which is used to receive and store the second target traveling wave signal when the second excitation electrode is working.

[0067] The signal processing module is used to receive the first target traveling wave signal when the first excitation electrode is working, and to determine the four first traveling wave signals corresponding to the first target traveling wave signal and the two second traveling wave signals corresponding to the second target traveling wave signal respectively. Based on the four first traveling wave signals and the two second traveling wave signals, the absolute angular displacement value is determined and output through data fusion and signal processing.

[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 hardware circuits, shaping circuits, and a signal processing unit. The hardware circuits are connected to the receiving electrodes and the shaping circuits, and the shaping circuits are connected to the signal processing unit.

[0069] The hardware circuit can be used to receive two second target traveling wave signals when the first excitation electrode is not working and the second excitation electrode is working, and to perform subtraction processing on the second target traveling wave signals to obtain the second traveling wave signal U. 02 Among them, U 02 =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=8×10 4 π. θ is the precisely measured angular displacement value.

[0070] The second traveling wave signal is a sine wave. After receiving the second traveling wave signal, the signal processing module can use a shaping circuit to shape it from a sine wave into a square wave, i.e., the shaped second traveling wave signal is a square wave. Afterward, the square wave second traveling wave signal can be sent to the signal processing unit for storage.

[0071] The hardware circuit can be used to receive signals when the first excitation electrode is working and the second excitation electrode is not working. The number of receiving channels is the same as the number of first receiving electrodes of the first receiving electrode and the number of probes of the first reflecting electrode. It also performs signal processing on the first target traveling wave signal to obtain the first traveling wave signal U. 01 Among them, U 01 =K e U m *sin[ωt+16θ].

[0072] The first traveling wave signal is also a sine wave. After receiving the first traveling wave signal, the signal processing module can use a shaping circuit to shape the first traveling wave signal from a sine wave into a square wave, that is, the shaped first traveling wave signal is a square wave. After that, the square wave first traveling wave signal can be input to the signal processing unit.

[0073] The signal processing unit can perform precision measurement using the first traveling wave signal of the square wave, which can be combined 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.

[0074] On the other hand, the signal processing unit can realize the coarse measurement part through the first traveling wave signal and the second traveling wave signal of the square wave. That is, it can perform pole positioning processing on the first traveling wave signal and the second traveling wave signal of the square wave to obtain the coarse pole position value.

[0075] By combining the precise angular displacement value and the coarse pole position value, the absolute angular displacement value can be obtained, which is the output result of the absolute angular displacement sensor.

[0076] 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 for phase comparison with the first and second traveling wave signals of the square wave. The signal processing unit can be a Field Programmable Gate Array (FPGA) chip signal processing system.

[0077] In this embodiment of the invention, both the coarse measurement of the polar position value and the fine measurement of the angular displacement value use the first traveling wave signal and the second traveling wave signal. The signal difference is small, which realizes both absolute measurement and ensures measurement accuracy.

[0078] Based on the above embodiments, the absolute time-grid angular displacement sensor based on combined modulation provided in the embodiments of the present invention has the following characteristics: the first receiving electrode is composed of a first number of first receiving electrodes arranged in a circle with equal spacing along the circumference, and the second receiving electrode is composed of a second number of second receiving electrodes arranged with equal spacing along the radial direction.

[0079] Specifically, in this embodiment of the invention, the first receiving electrode 31 is composed of a first 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 second number of second receiving electrodes arranged in a circle at equal intervals along the circumference. The first number and the second number can be set as needed, for example, they can be set to even numbers such as 2, 4, or 6, and are not specifically limited here. Figure 5 The example only provides the case where the first quantity is 4 and the second quantity is 2.

[0080] Based on the above embodiments, the absolute time-grid angle displacement sensor based on combined modulation provided in the embodiments of the present invention, wherein each first receiving electrode in the first receiving electrode serves as an output electrode for a first target traveling wave signal;

[0081] 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.

[0082] Specifically, in this embodiment of the invention, each first receiving electrode in the first receiving electrode serves as an output electrode for one first target traveling wave signal. For example, if the first receiving electrode has m first receiving electrodes, then there are m channels of the first target traveling wave signal.

[0083] The 2n1+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 2n1+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. n1 takes all integers from 0 to M1-1 in sequence, and M1 represents the number of pairs of the second receiving electrode.

[0084] Based on the above embodiments, the absolute time-grid angular displacement sensor based on combined modulation provided in the embodiments of the present invention has the following characteristics: the first excitation electrode has a third number of first excitation electrode groups, the second excitation electrode has the third number of second excitation electrode groups, the first sensing electrode has a fourth number of probes, and the second sensing electrode has a fifth number of probes.

[0085] The first excitation electrode is composed of a circle of first excitation electrode pieces arranged at equal intervals along the circumference, which is the product of the third number and the number of pole pairs of the first excitation electrode. Each adjacent third 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.

[0086] 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 third number and the number of pole pairs of the second excitation electrode. Each adjacent third 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.

[0087] 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 fourth number and the third number of the first sensing electrode pairs. Each adjacent fourth 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.

[0088] 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 fifth number and the fourth number of the second sensing electrode pairs. Each adjacent fifth number of second sensing electrode pieces forms a second sensing pair. The second sensing electrode pieces at the same position in each second sensing pair are connected in series to form a second sensing electrode group.

[0089] Specifically, the first excitation electrode 11 has a third number of A first excitation electrode groups, the second excitation electrode also has a third number of A second excitation electrode groups, the first sensing electrode 21 has a fourth number of B probes, and the second sensing electrode 22 has a fifth number of C probes. A, B, and C can all be set as needed; for example, A, B, and C can all be set to any number greater than 2.

[0090] The first excitation electrode 11 is composed of A*M2 first excitation electrode pieces arranged in a circle at equal intervals along the circumference. The first excitation electrode pieces can be fan-shaped annular electrode pieces 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 each two adjacent first excitation electrode pieces is 2.8125°.

[0091] Each pair of adjacent A first excitation electrodes forms a first excitation pair, and M2 is the number of first excitation pairs. M2 can be 16, or it can be set as needed.

[0092] 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.

[0093] For example, if A = 4 and M2 = 16, then the 4n2+1th first excitation electrode is connected to a group via the first excitation signal connection line, forming the first excitation electrode group G11; the 4n2+2th first excitation electrode is connected to a group via the second excitation signal connection line, forming the first excitation electrode group G12; the 4n2+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 4n2+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. n2 takes all integers from 0 to M2-1.

[0094] The second excitation electrode 12 consists of three identical second excitation electrode pieces, A*M3 (the product of A and the number of poles M3 of the second excitation electrode), 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 2.8125°. The central angle corresponding to the interval between two adjacent second excitation electrode pieces is 2.8125°.

[0095] Each pair of adjacent A second excitation electrodes forms a second excitation pair, and M3 is the number of second excitation pairs. M3 can be 16, or it can be set as needed.

[0096] 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, and the number of second excitation electrode groups is also A. The excitation signal connection lines used to form the second excitation electrode groups are all 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.

[0097] For example, if A = 4 and M3 = 16, then the 4n3+1th second excitation electrode is connected to a group via the fifth excitation signal connection line, forming the second excitation electrode group G15; the 4n3+2th second excitation electrode is connected to a group via the sixth excitation signal connection line, forming the second excitation electrode group G16; the 4n3+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 4n3+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. n3 takes all integers from 0 to M3-1.

[0098] The first sensing electrode 21 consists of B*M4 first sensing electrode pieces arranged in a circle at equal intervals along the circumference. Each adjacent B first sensing electrode pieces form a first sensing pair, and the number of first excitation pairs is M4.

[0099] 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 M4=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.

[0100] 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 B. 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.

[0101] If B = 4 and M4 = 16, then the 4n4+1th first sensing electrode is connected to form a group G21 through the first sensing signal connection line; the 4n4+2th first sensing electrode is connected to form a group G22 through the second sensing signal connection line; the 4n4+3th first sensing electrode is connected to form a group G23 through the third sensing signal connection line; and the 4n4+4th first sensing electrode is connected to form a group G24 through the fourth sensing signal connection line. The first, second, third, and fourth sensing signal connection lines are all loop conductors located on the same wiring layer.

[0102] The second sensing electrode 22 consists of C*M5 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 C = 4 and M5 = 16, 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.

[0103] Each pair of C adjacent second sensing electrodes forms a second sensing pair, and the number of first excitation electrodes is M5. 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 C. 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.

[0104] The 4n5+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 4n5+2nd second sensing electrodes are connected in a group via the sixth sensing signal connection line to form a group of second sensing electrodes G26. The 4n5+3rd second sensing electrodes are connected in a group via the seventh sensing signal connection line to form a group of second sensing electrodes G27. The 4n5+4th second sensing electrodes are connected in a group via the eighth sensing signal connection line to form a group of second sensing electrodes G28. The fifth, sixth, seventh, and eighth sensing signal connection lines are all loop conductors and are located on the same wiring layer.

[0105] Based on the above embodiments, the absolute time-grid angle displacement sensor based on combined modulation provided in the embodiments of the present invention has a first reflective electrode formed by the fourth number of first reflective plates arranged radially at equal intervals, and the first reflective plates are connected one-to-one with the first sensing electrode group.

[0106] The second reflective electrode is composed of a fifth number of second reflective electrodes arranged in a circle at equal intervals along the circumference, and the second reflective electrodes are connected one-to-one with the second inductive electrode group.

[0107] Specifically, in this embodiment of the invention, the first reflective electrode 23 is composed of B first reflective electrodes arranged at equal intervals along the radial direction, and the first reflective electrodes are connected to the first sensing electrode group one-to-one. The second reflective electrode 24 is composed of a fifth number of C second reflective electrodes arranged at equal intervals along the circumference, and the second reflective electrodes are connected to the second sensing electrode group one-to-one.

[0108] When the absolute time-grid angular displacement sensor performs measurements, the rotor base 2 rotates parallel to the first stator base 1 and the second stator base 3. First, four sinusoidal excitation signals of the same frequency and amplitude, with a phase difference of 90°, are applied to the second excitation electrode. At this time, the first excitation electrode is not working. The initial traveling wave signal coupled to the second sensing electrode is transmitted to the second reflecting electrode. Then, through the coupled electric field between the second reflecting electrode and the second receiving electrode, two second target traveling wave signals of the same frequency and amplitude, with a phase difference of 180°, are output on the second receiving electrode.

[0109] Within 1 ms, four sinusoidal excitation signals of the same frequency and amplitude, with phase differences of 90°, are switched to the first excitation electrode. During this time, the second excitation electrode remains inactive. The initial traveling wave signal coupled to the first induction electrode is transmitted to the first reflection electrode. Then, through the coupled electric field between the first reflection electrode and the first receiving electrode, a signal with equal amplitude, the same frequency, and sequentially different phase differences is output on the first receiving electrode. The first target traveling wave signal of the C-path.

[0110] Based on the above embodiments, the absolute time-grid angular displacement sensor based on combined modulation 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.

[0111] 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.

[0112] Based on the above embodiments, the absolute time-grid angular displacement sensor based on combined modulation 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.

[0113] 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 / M6, where M6 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 / M7, where M7 is the number of poles of the second receiving electrode. Here, it is sufficient that α is slightly less than 180 / M6 and β is slightly less than 180 / M7.

[0114] In summary, the absolute time-grating angular displacement sensor based on combined modulation provided in this embodiment of the invention has the following effects:

[0115] (1) The three-layer structure layout increases the available area on each substrate, resulting in a larger contact area and stronger signal quality. By placing the first excitation electrode and the second excitation electrode on the first surface of the first stator substrate and the first receiving electrode and the second receiving electrode on the fourth surface of the second stator substrate, the interference of the excitation signal on the output displacement signal is reduced during operation, thereby improving the quality and reliability of the output displacement signal.

[0116] (2) 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 first reflecting electrode, the second reflecting electrode, the first receiving electrode and the second receiving electrode. The rotor base does not need to lead a signal output line, which improves the reliability of the sensor and its application range is wider.

[0117] (3) The second traveling wave signal is processed to obtain the precise angular displacement value. The phase relationship between the first and second traveling wave signals is processed to obtain the coarse pole position value. Both the coarse pole position value and the precise angular displacement value use the first and second traveling wave signals. The signal difference is small, which realizes absolute measurement and ensures measurement accuracy.

[0118] 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.

[0119] 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.

[0120] 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 combined modulation, 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 layer includes a first excitation electrode and a second excitation electrode; the sensing electrode layer includes a first sensing electrode and a second sensing electrode; the reflective electrode layer includes a first reflective electrode and a second reflective electrode; and the receiving electrode layer includes a first receiving electrode and a second receiving electrode. The second receiving electrode has a differential structure. The first excitation electrode, the first sensing electrode, the first reflective electrode, and the first receiving electrode correspond to each other, as do the second excitation electrode, the second sensing electrode, the second reflective electrode, and the second receiving electrode. The first receiving electrode includes a first receiving electrode plate, and the second receiving electrode includes a second receiving electrode plate. The first receiving electrode plate is in the shape of a ring, and the second receiving electrode is in the shape of 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 their starting and ending points. The first receiving electrode is composed of a first number of first receiving electrodes arranged in a circle at equal intervals along the radial direction, and the second receiving electrode is composed of a second number of second receiving electrodes arranged at equal intervals along the circumferential direction. Each of the first receiving electrodes in the first receiving electrode serves as an output electrode for one 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.

2. The absolute time-grid angular displacement sensor based on combined modulation according to claim 1, characterized in that, 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 the first target traveling wave signal and the second target traveling wave signal, respectively.

3. The absolute time-grid angular displacement sensor based on combined modulation according to claim 2, 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 includes a storage module, which is used to receive and store the second target traveling wave signal when the second excitation electrode is working. The signal processing module is used to receive the first target traveling wave signal when the first excitation electrode is working, and to determine the four first traveling wave signals corresponding to the first target traveling wave signal and the two second traveling wave signals corresponding to the second target traveling wave signal respectively. Based on the four first traveling wave signals and the two second traveling wave signals, the absolute angular displacement value is determined and output through data fusion and signal processing.

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

5. The absolute time-grid angular displacement sensor based on combined modulation according to claim 4, characterized in that, The first reflective electrode is formed by a fourth number of first reflective plates arranged at equal intervals along the radial direction, and the first reflective plates are connected one-to-one with the first sensing electrode group; The second reflective electrode is composed of a fifth number of second reflective electrodes arranged in a circle at equal intervals along the circumference, and the second reflective electrodes are connected one-to-one with the second inductive electrode group.

6. The absolute time-grid angular displacement sensor based on combined modulation according to any one of claims 1-5, 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.

7. The absolute time-grid angular displacement sensor based on combined modulation according to any one of claims 1-5, 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 second receiving electrode is less than 180°.

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