Angular displacement sensor, angle measuring method and motor

Abstract

The invention relates to an angular displacement sensor, an angle measurement method and a motor. The angular displacement sensor comprises a circuit board which is provided with a processing circuit and an excitation circuit; the accurate measurement module comprises a rotor and a stator which are oppositely arranged, and the rotor is located between the stator and the circuit board; the side, facing the stator, of the rotor is provided with a collecting electrode and an exciting electrode, the side, facing the rotor, of the stator is provided with a coupling electrode and a sensitive electrode electrically connected with the coupling electrode, and the exciting electrode is excited by an electric signal from an exciting circuit and coupled with the coupling electrode to enable the sensitive electrode to generate an electric signal. A capacitor is formed between the acquisition electrode and the sensitive electrode; the rough measurement module comprises a photosensitive element and a light source, one of the photosensitive element and the light source is arranged on the circuit board, the other is arranged on the stator, and the rotor and the circuit board are respectively provided with light through holes; and the processing circuit is used for acquiring the absolute rotation angle of the rotor according to the light intensity pulse times detected by the photosensitive element and the capacitance value of the capacitor formed by the acquisition electrode and the sensitive electrode.

Description

Technical Field

[0001] The present disclosure relates to the field of electromechanical technology, and in particular to an angular displacement sensor, an angle measurement method and a motor. Background Art

[0002] Angular displacement sensors are widely used and have a wide range of precision requirements. From low-end civilian gimbals, mid-range industrial robots, to more demanding shipborne weapons, various mechanical systems have put forward higher and higher requirements for angular displacement sensors. The demand for small-sized, low-power angular displacement sensors is also increasing. Summary of the invention

[0003] The present disclosure provides an angular displacement sensor, an angle measurement method and a motor to solve the deficiencies in the related art.

[0004] According to a first aspect of an embodiment of the present disclosure, there is provided an angular displacement sensor, comprising:

[0005] A circuit board, wherein the circuit board is provided with a processing circuit and an excitation circuit;

[0006] A precision measurement module, the precision measurement module comprises a rotor and a stator arranged opposite to each other, the rotor is located between the stator and the circuit board; a collection electrode and an excitation electrode are provided on the side of the rotor facing the stator, a coupling electrode and a sensitive electrode electrically connected to the coupling electrode are provided on the side of the stator facing the rotor, the excitation electrode is excited by an electrical signal from the excitation circuit, and is coupled with the coupling electrode so that the sensitive electrode generates an electrical signal, and a capacitor is formed between the collection electrode and the sensitive electrode;

[0007] A rough measurement module, the rough measurement module comprising a photosensitive element and a light source, one of the photosensitive element and the light source is arranged on the circuit board, and the other is arranged on the stator, and the rotor and the circuit board are respectively provided with light holes;

[0008] The processing circuit is used to obtain the absolute rotation angle of the rotor according to the number of light intensity pulses detected by the photosensitive element and the capacitance value of the capacitor formed by the collection electrode and the sensitive electrode.

[0009] Optionally, the rotor and the stator are coaxially arranged annular structures; when the angular displacement sensor is in an initial position, the photosensitive element, the light source and the light through hole are arranged along the axial direction of the rotor.

[0010] Optionally, in the radial direction of the rotor, the light-through hole provided on the rotor is located outside the collection electrode and the excitation electrode.

[0011] Optionally, the light-through hole is an arc hole coaxially arranged with the rotor;

[0012] In the radial direction of the rotor, the radial width of the arc hole is 1 / 6-1 / 4 of the radial width of the collecting electrode.

[0013] Optionally, the plurality of collecting electrodes are arranged along the circumference of the rotor and are divided into N periods, each period includes M collecting electrodes, and in the clockwise direction, the collecting electrodes of the same order in the N periods are electrically connected as a group; the M collecting electrodes of any period are electrically connected to the output port of the rotor, and the output port is electrically connected to the processing circuit.

[0014] Optionally, the rotor comprises:

[0015] An electrode layer, wherein the electrode layer includes the collection electrode and the excitation electrode;

[0016] First shielding layer;

[0017] Second shielding layer;

[0018] A signal interconnection layer, the signal interconnection layer is located between the first shielding layer and the second shielding layer, the first shielding layer is located between the signal interconnection layer and the electrode layer, the signal interconnection layer includes M wires, and the M wires are electrically connected to the M collection electrodes of each period in a one-to-one correspondence;

[0019] Wherein, a ceramic substrate is arranged between two adjacent layers among the electrode layer, the first shielding layer, the signal interconnection layer and the second shielding layer.

[0020] Optionally, each of the collection electrodes includes a collection area and an interconnection area electrically connected to the collection area, the interconnection area extends radially inward relative to the collection area along the rotor, and in the circumferential direction of the rotor, the width of the interconnection area is smaller than the width of the collection area, and the M interconnection areas in each period are electrically connected to the M wires in a one-to-one correspondence.

[0021] Optionally, the sensitive electrode includes a plurality of electrode sheets arranged along the circumference of the stator, adjacent electrode sheets are electrically connected, and each electrode sheet includes a symmetrically arranged radial outer edge and a radial inner edge, and the radial outer edge is arranged in the shape of the first half period of a sine curve;

[0022] At the initial position of the angular displacement sensor, each electrode sheet is arranged opposite to M collection electrodes of the same period, and the number of the electrode sheets is equal to the number of periods of the collection electrodes.

[0023] According to a second aspect of an embodiment of the present disclosure, there is provided an angle measurement method, which is applied to any one of the above-mentioned angular displacement sensors, and the measurement method comprises:

[0024] Obtaining the capacitance value of the capacitor formed between the collection electrode and the sensitive electrode;

[0025] Obtaining the number of times the photosensitive element collects light intensity pulses;

[0026] The rotation angle of the rotor relative to the stator is calculated according to the capacitance value and the number of light intensity pulses.

[0027] According to a third aspect of an embodiment of the present disclosure, there is provided a motor, comprising an angular displacement sensor as described in any one of the above.

[0028] The technical solution provided by the embodiments of the present disclosure may have the following beneficial effects:

[0029] It can be seen from the above embodiments that the processing circuit and the excitation circuit in the present disclosure are designed on the same board, which is conducive to the miniaturization of the angular displacement sensor. The coarse measurement module adopts a light source and a photosensitive element to reduce the power consumption of the angular displacement sensor and realize a miniaturized and low-power angular displacement sensor.

[0030] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0032] Figure 1 is a schematic cross-sectional view of an angular displacement sensor according to an exemplary embodiment.

[0033] Figure 2 The figure is a schematic diagram showing a side of a rotor facing a stator according to an exemplary embodiment.

[0034] Figure 3 The figure is a schematic diagram showing a side of a stator facing a rotor according to an exemplary embodiment.

[0035] Figure 4 It is a measurement principle diagram of an angular displacement sensor according to an exemplary embodiment.

[0036] Figure 5 is a schematic cross-sectional view of a rotor according to an exemplary embodiment.

[0037] Figure 6 The figure is a schematic diagram showing electrical connection between a collection electrode and a signal interconnection layer according to an exemplary embodiment.

[0038] Figure 7 The figure is a flow chart of an angle measurement method according to an exemplary embodiment. DETAILED DESCRIPTION

[0039] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0040] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. The singular forms of "a", "said" and "the" used in this disclosure and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0041] It should be understood that although the terms first, second, third, etc. may be used in the present disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present disclosure, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0042] Figure 1 FIG. 1 is a cross-sectional schematic diagram of an angular displacement sensor according to an exemplary embodiment. Figure 1 As shown, the angular displacement sensor includes a circuit board 1, a precision measurement module 2 and a rough measurement module 3. The circuit board 1 may include a board body 11, a processing circuit 12 and an excitation circuit 13. The processing circuit 12 and the excitation circuit 13 are both arranged on the same board body 11, that is, they can be integrated on the circuit board 1 for a common board design, which can greatly reduce the volume of the angular displacement sensor, is conducive to the miniaturization of the angular displacement sensor, and makes room for layout for other components of the electronic equipment configured with the angular displacement sensor, such as a small electromechanical rotating system. The precision measurement module 2 includes a relatively arranged rotor 21 and a stator 22. The rotor 21 and the stator 22 can both be arranged in a circular plate-shaped structure, and the rotor 21 and the stator 22 are coaxially arranged, and the rotor 21 is located between the stator 22 and the circuit board 1. In this way, the inner cavity of the rotor 21 and the stator 22 can be used to install other mechanical parts or electronic devices of the equipment to which the angular displacement sensor belongs. For example, the angular displacement sensor can be applied to a motor system, and the inner cavity of the rotor 21 and the stator 22 can be used to assemble related parts of the motor system, such as a conductive slip ring of the motor system.

[0043] like Figure 2 As shown, in order to realize signal collection and signal transmission, the rotor 21 is provided with a collection electrode 211 and an excitation electrode 212 on the side facing the stator 22, as shown in FIG. Figure 3 As shown, a coupling electrode 221 and a sensitive electrode 222 are provided on the side of the stator 22 facing the rotor 21. The sensitive electrode 222 and the coupling electrode 221 are electrically connected. The excitation electrode 212 is excited by the electrical signal from the excitation circuit 13 and coupled with the coupling electrode 221 so that the sensitive electrode 222 generates an electrical signal. A capacitor is formed between the collection electrode 211 and the sensitive electrode 222.

[0044] The rough measurement module 3 includes a photosensitive element 31 and a light source 32. The photosensitive element 31 is arranged on the circuit board 1, that is, the photosensitive element 31 is electrically connected to the board body 11 of the circuit board 1. The light source 32 is fixedly arranged on the stator 22, and the rotor 21 and the stator 22 are respectively provided with light holes 4, so that when the angular displacement sensor is in the initial position, when the light source 32, the light hole 4 and the photosensitive element 31 are aligned in the axial direction of the rotor 21, the photosensitive element 31 can detect the light emitted by the light source 32. It can be understood that the photosensitive element 31 and the light hole 4 both rotate with the rotor 21, the light source 32 is fixed relative to the stator 22, and the photosensitive element 31 can detect the light emitted by the light source 32 once for each rotation of the rotor 21 relative to the stator 22, forming a light intensity pulse related to the angle, and thus it can be determined whether the rotor 21 has returned to the initial position. Therefore, the number of rotations of the rotor 21 relative to the stator 22 can be determined by the number of light intensity pulses detected by the photosensitive element 31. In some other embodiments, the light source 32 may be disposed on the circuit board 1, that is, the light source 32 is electrically connected to the board body 11 of the circuit board 1, and the photosensitive element 31 is fixedly disposed on the stator 22, and the present disclosure does not limit this. Of course, in order to simplify the angle calculation, the angular displacement sensor can be reset to the initial position after each angle measurement is completed, that is, the same initial position is used as the zero point of the absolute rotation angle each time.

[0045] The processing circuit 12 can be used to obtain the absolute rotation angle of the rotor 21 relative to the stator 22 according to the number of light intensity pulses detected by the photosensitive element 31 and the capacitance value of the capacitor formed between the acquisition electrode 211 and the sensitive electrode 222. The processing circuit 12 may include an angle acquisition module and a coarse-fine coupling angle solution module, which collects the capacitance value and the number of light intensity pulses through the angle acquisition module, and calculates the absolute rotation angle through the coarse-fine coupling angle settlement module, thereby improving the angle measurement resolution and angle measurement accuracy. Moreover, the coarse measurement module adopts a low-power photosensitive element and a low-power visible light source, and adopts a low-power circuit design, which helps to reduce system power consumption. The light intensity-based angle rough measurement and capacitive angle precision measurement scheme, based on the coarse-fine coupling solution to obtain the initial angle and the angle increment obtained by the angle precision measurement module, accumulate the output to obtain the absolute angle measurement value in real time, thereby improving the angle measurement resolution and angle measurement accuracy.

[0046] The light source may include an LED light source to further reduce the power consumption of the angular displacement sensor. The photosensitive element 31 uses a low-power visible light sensitive dedicated chip. The height of the entire angular displacement sensor system is less than or equal to 1.3 mm (including the height of the stator 22, the rotor 21, the height of the sensitive element 31 and the coupling air gap height), and the inner diameter and outer diameter can be determined according to the requirements of the device to which it belongs.

[0047] In some embodiments, in the radial direction of the rotor 21, the light-through hole provided on the rotor 21 is located outside the collection electrode 211 and the excitation electrode 212, so as to avoid the setting of the light-through hole affecting the area requirements of the collection electrode 211 and the excitation electrode 212. The excitation electrode 212 can be located inside the collection electrode 211, the collection electrode 211 can be a circular ring structure, and the excitation electrode 212 can be a circular plate structure or a circular ring structure.

[0048] In some embodiments, the light-through hole 4 of the rotor 21 is an arc hole coaxially arranged with the rotor 21, and in the radial direction of the rotor 21, the radial width of the arc hole is 1 / 6-1 / 4 of the radial width of the collection electrode 211. For example, the radial width of the arc hole is 1 / 5 of the radial width of the collection electrode 211, and the volume occupied is very small, so that when the diameter of the rotor 21 is constant, more space can be saved for the collection electrode 211 and the excitation electrode 212.

[0049] In the above-mentioned embodiments, the multiple collecting electrodes 211 of the rotor 21 are arranged along the circumference of the rotor 21 and can be divided into N periods, each period includes M collecting electrodes, and in the clockwise direction, the collecting electrodes with the same sequence in the N periods are electrically connected as a group, and the M collecting electrodes 211 of any period are electrically connected to the output port of the rotor 21, and the output port is electrically connected to the processing circuit 12. For example, the rotor 21 is provided with 64 collecting electrodes, which are subdivided into 16 periods, each period includes 4 collecting electrodes, and in the clockwise direction, the first collecting electrodes 211 of each period are interconnected, the second collecting electrodes 211 of each period are interconnected, the third collecting electrodes 211 of each period are interconnected, and the fourth collecting electrodes 211 of each period are interconnected, and finally four output capacitors are obtained.

[0050] For example, Figure 4 As shown, the four-way output capacitor includes a precise measurement sin+ signal, a precise measurement sin- signal, a precise measurement cos+ signal and a precise measurement cos- signal. According to the capacitive coupling principle, the size of the capacitance formed between the collection electrode 211 and the sensitive electrode 222 is proportional to the collection voltage of the collection electrode 211. Therefore, the precise measurement sin+ signal, the precise measurement sin- signal, the precise measurement cos+ signal and the precise measurement cos- signal can be capacitor-demodulated by their respective corresponding modulation circuits C / V, thereby outputting four output voltages. The four output voltages are converted by R / D to obtain a precise measurement angle, which can be input into a coarse-precision coupling angle solving module to obtain the absolute rotation angle of the rotor 21 in combination with the coarse measurement result of the coarse measurement module.

[0051] Among them, the coupling electrode 221 includes a plurality of electrode sheets, the number of electrode sheets of the coupling electrode 221 is equal to the number of cycles formed by the collection electrode 211, and the number of electrode sheets can be defined as the pole pair number of the precision measurement module. The higher the pole pair number within a certain size range, the better the averaging effect of the circumferential angle measurement error, and the higher the angle detection accuracy. The pole pair number of the precision measurement module can be determined by comprehensively considering the accuracy, resolution and manufacturing error factors. Within a limited size range, the maximum design of the stator and rotor coupling area of ​​the precision measurement module helps to improve the sensitivity of angle detection.

[0052] The rotor 21 of the precision measurement module 2 can be manufactured based on a printed circuit board process, such as Figure 5As shown, the rotor 21 includes an electrode layer 213, a first shielding layer 214, a signal interconnection layer 215, and a second shielding layer 216. The electrode layer 213 includes a collection electrode 211 and an excitation electrode 212, the signal interconnection layer 215 is located between the first shielding layer 214 and the second shielding layer 216, and the first shielding layer 214 is located between the signal interconnection layer 215 and the electrode layer 213. That is, the electrode layer 213, the first shielding layer 214, the signal interconnection layer 215 and the second shielding layer 216 are stacked in sequence in the direction of the rotor 21 away from the stator 22. The signal interconnection layer 215 includes M wires 217, and the M wires 217 are electrically connected to the M collection electrodes 211 of each cycle in a one-to-one correspondence, so as to realize a scheme in which the collection electrodes with the same sequence in N cycles are electrically connected as a group.

[0053] Among them, a ceramic substrate is arranged between two adjacent layers of the electrode layer 213, the first shielding layer 214, the signal interconnection layer 215 and the second shielding layer 216. Compared with conventional dielectric substrates, the use of ceramic substrates has higher processing accuracy, so it is beneficial to improve the angle measurement accuracy of the precision measurement module 2 equipped with the ceramic substrate. The first layer and the third layer of the rotor 21 in the direction pointing to the stator 22 are shielding layers, which can reduce the influence of signal coupling and changes in the external electromagnetic environment on the detection output. The stator 22 can also be manufactured by a circuit board process. The coupling electrode 221 and the sensitive electrode 222 of the stator 22, as well as the collection electrode 211 and the excitation electrode 212 of the rotor 21 are all made by the process of surface gold deposition after via filling. No other surface treatment is performed on the electrode surface, which reduces the capacitance output change caused by the change in the medium distribution on the stator and rotor coupling surfaces, and improves the angle measurement accuracy.

[0054] like Figure 6 As shown, each collection electrode 211 includes a collection area 2111 and an interconnection area 2112 electrically connected to the collection area 2111. The interconnection area 2112 extends radially inward relative to the collection area 2111 along the rotor 21. In the circumferential direction of the rotor 21, the width of the interconnection area 2112 is smaller than the width of the collection area 2111. The M interconnection areas 2112 in each cycle are electrically connected to the M wires in a one-to-one correspondence. Based on this, compared with the solution in which the collection area 2111 covers the M wires 217, due to the reduction in the width of the interconnection area 2112, in the axial direction of the rotor 21, the overlap area between the collection electrode 211 and the M wires is reduced, the signal coupling between different paths is reduced, the parasitic capacitance between the wire and the collection electrode 211 can be reduced, and the accuracy of angle precision measurement can be improved.

[0055] In some embodiments, the sensitive electrode 222 includes a plurality of electrode sheets arranged along the circumference of the stator 22, adjacent electrode sheets are electrically connected, and each electrode sheet includes a symmetrically arranged radial outer edge 2221 and a radial inner edge 2222, and the radial outer edge 2221 is arranged in the shape of the first half period of a sine curve, such as Figure 3 As shown; in the initial position of the angular displacement sensor, each electrode piece is arranged opposite to the M collection electrodes 211 of the same period, and the number of coupling electrodes is equal to the number of periods of the collection electrodes 211. Figure 6 The black dot in the middle represents the location where the interconnection area 2112 is electrically connected to the corresponding conductive wire through the metallized hole.

[0056] Based on the technical solution disclosed in this disclosure, Figure 7 As shown, the present disclosure also provides an angle measurement method, which is applied to the angular displacement sensor described in any of the above embodiments. The measurement method includes the following steps:

[0057] In step 701 , the capacitance value of the capacitor formed between the collection electrode 211 and the sensitive electrode 222 is obtained.

[0058] In step 702, the number of times the light intensity pulses are collected by the photosensitive element 31 is obtained.

[0059] In step 703, the rotation angle of the rotor relative to the stator is calculated according to the capacitance value and the number of light intensity pulses.

[0060] In this embodiment, a sinusoidal voltage with stable frequency and amplitude can be applied to the excitation electrode 212 of the rotor 21 of the precision measurement module 2. Through capacitive coupling, a voltage of the same frequency acts on the coupling electrode 221 of the stator 22. The coupling electrode 221 is connected to the sensitive electrode 222. The sensitive electrode 221 in the form of sinusoidal petals forms a sensitive capacitor with the four-way collection electrode 211 on the rotor 21. When the rotor 21 of the precision measurement module 2 has an angle change relative to the stator 22, the four-way capacitance value changes at the same time, and the capacitor demodulation output voltage is realized by the demodulation circuit, and then the relative angle information of the stator and rotor is obtained by R / D conversion. When the stator and rotor of the precision measurement module rotate relative to each other until the light source 32 is directly above the light hole, the visible light is sensed by the photosensitive element 31, and a light intensity pulse related to the angle is formed. When the stator 22 and the rotor 21 rotate relative to each other, the processing circuit 12 simultaneously reads the light intensity and the relative angle information of the stator 22 and the rotor 21, and performs a coarse-fine coupling solution in combination with the angle range covered by the peak light intensity to obtain the initial angle. Based on the initial angle and whether the precise relative angle crosses the initial angular position, the relative angle output of the stator 22 and the rotor 21 is continuously judged and accumulated on the basis of the initial angle to obtain the absolute angle.

[0061] Based on the technical solution of the present disclosure, a motor is also provided, which includes the angular displacement sensor described in any of the aforementioned embodiments. The miniaturization of the angular displacement sensor is beneficial to the compactness of the internal structure of the motor, and the inner cavity of the rotor 21 and the inner cavity of the stator 22 of the angular displacement sensor can also be used to accommodate relevant parts of the motor, which is beneficial to the miniaturization of the motor.

[0062] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the disclosure disclosed herein. The present disclosure is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The description and examples are to be considered exemplary only, and the true scope and spirit of the present disclosure are indicated by the following claims.

[0063] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. An angular displacement sensor, characterized in that: include: A circuit board, wherein the circuit board is provided with a processing circuit and an excitation circuit; A precision measurement module, the precision measurement module comprises a rotor and a stator arranged opposite to each other, the rotor is located between the stator and the circuit board; a collection electrode and an excitation electrode are provided on the side of the rotor facing the stator, a coupling electrode and a sensitive electrode electrically connected to the coupling electrode are provided on the side of the stator facing the rotor, the excitation electrode is excited by an electrical signal from the excitation circuit, and is coupled with the coupling electrode so that the sensitive electrode generates an electrical signal, and a capacitor is formed between the collection electrode and the sensitive electrode; A rough measurement module, the rough measurement module comprising a photosensitive element and a light source, one of the photosensitive element and the light source is arranged on the circuit board, and the other is arranged on the stator, and the rotor and the circuit board are respectively provided with light holes; The processing circuit is used to obtain the absolute rotation angle of the rotor according to the number of light intensity pulses detected by the photosensitive element and the capacitance value of the capacitor formed by the collection electrode and the sensitive electrode.

2. The angular displacement sensor according to claim 1, characterized in that: The rotor and the stator are coaxially arranged annular structures; when the angular displacement sensor is in an initial position, the photosensitive element, the light source and the light-through hole are arranged along the axial direction of the rotor.

3. The angular displacement sensor according to claim 1, characterized in that: In the radial direction of the rotor, the light-through hole provided in the rotor is located outside the collection electrode and the excitation electrode.

4. The angular displacement sensor according to claim 1, characterized in that: The light-through hole arranged on the rotor is a circular arc hole arranged coaxially with the rotor; In the radial direction of the rotor, the radial width of the arc hole is 1 / 6-1 / 4 of the radial width of the collecting electrode.

5. The angular displacement sensor according to claim 1, characterized in that: The plurality of collecting electrodes are arranged along the circumference of the rotor and are divided into N periods, each period includes M collecting electrodes, and in the clockwise direction, the collecting electrodes of the same order in the N periods are electrically connected as a group; the M collecting electrodes of any period are electrically connected to the output port of the rotor, and the output port is electrically connected to the processing circuit.

6. The angular displacement sensor according to claim 5, characterized in that: The rotor comprises: An electrode layer, wherein the electrode layer includes the collection electrode and the excitation electrode; First shielding layer; Second shielding layer; A signal interconnection layer, the signal interconnection layer is located between the first shielding layer and the second shielding layer, the first shielding layer is located between the signal interconnection layer and the electrode layer, the signal interconnection layer includes M wires, and the M wires are electrically connected to the M collection electrodes of each period in a one-to-one correspondence; Wherein, a ceramic substrate is arranged between two adjacent layers among the electrode layer, the first shielding layer, the signal interconnection layer and the second shielding layer.

7. The angular displacement sensor according to claim 6, characterized in that: Each of the collection electrodes comprises a collection area and an interconnection area electrically connected to the collection area. The interconnection area extends radially inwardly of the rotor relative to the collection area. In the circumferential direction of the rotor, the width of the interconnection area is smaller than the width of the collection area. The M interconnection areas in each period are electrically connected to the M wires in a one-to-one correspondence.

8. The angular displacement sensor according to claim 7, characterized in that: The sensitive electrode comprises a plurality of electrode sheets arranged along the circumference of the stator, adjacent electrode sheets are electrically connected, each electrode sheet comprises a symmetrically arranged radial outer edge and a radial inner edge, and the radial outer edge is arranged in the shape of the first half period of a sine curve; At the initial position of the angular displacement sensor, each electrode sheet is arranged opposite to M collection electrodes of the same period, and the number of the electrode sheets is equal to the number of periods of the collection electrodes.

9. An angle measurement method, characterized in that: The angular displacement sensor applied to any one of claims 1 to 8, wherein the measuring method comprises: Obtaining the capacitance value of the capacitor formed between the collection electrode and the sensitive electrode; Obtaining the number of times the photosensitive element collects light intensity pulses; The rotation angle of the rotor relative to the stator is calculated according to the capacitance value and the number of light intensity pulses.

10. A motor, characterized in that: Comprising the angular displacement sensor as claimed in any one of claims 1-8.

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