Angle measurement device and angle measurement method

Abstract

An angle measurement device and an angle measurement method. The angle measurement device comprises: a stator (210), wherein a first surface of the stator (210) is provided with a first electrode plate (211) and a plurality of second electrode plates (212) spaced apart from the first electrode plate (211), the plurality of second electrode plates (212) are arranged around the periphery of the first electrode plate (211), and the first electrode plate (211) and the second electrode plates (212) are connected to a detection circuit; and a rotor (220), wherein a second surface of the rotor (220) is provided with a first floating electrode plate (221) and a second floating electrode plate (222) connected to each other, the first floating electrode plate (221) is arranged directly facing the first electrode plate (211) to form a first capacitor, and the second floating electrode plate (222) is arranged directly facing the second electrode plates (212) to form second capacitors. The angle measurement device and the angle measurement method are conducive to improving the accuracy and stability of rotation angle measurement.

Description

Angle detection device and angle detection method Cross-reference to related applications

[0001] The present disclosure claims priority to Chinese Patent Application No. 202410994493.9, filed on July 23, 2024, entitled “Angle detection device and angle detection method”, which is incorporated by reference in its entirety. TECHNICAL FIELD

[0002] Embodiments of the present application relate to the technical field of angle measurement devices, and in particular to an angle detection device and an angle detection method. BACKGROUND

[0003] Measuring the rotation angle of a shaft is of great significance in applications such as potentiometers, trigger keys, foldable devices, and servo motors. A common technical means for measuring the rotation angle of a shaft is to use a magnet and a Hall chip detection structure to measure the rotation angle of the shaft. Changes in direction and angle will change the distance between the magnet and the Hall chip, so the change in the analog signal output by the Hall chip can reflect the rotation angle of the shaft.

[0004] However, on the one hand, external magnetic fields and the like will interfere with the detection of the rotation angle of the shaft using this technical means. On the other hand, thermal expansion and contraction of components with temperature changes and aging of related components can cause changes in the distance between the magnet and the Hall chip. The above factors can further cause deviations in the precision of the Hall chip signal, ultimately compromising the accuracy of the detection of the rotation angle of the shaft. SUMMARY

[0005] Embodiments of the present application provide an angle detection device and an angle detection method, which at least facilitate improving the accuracy and stability of rotation angle detection.

[0006] According to some embodiments of the present application, the present application provides an angle detection device, comprising: a stator, the first surface of the stator having a first pole plate and a plurality of second pole plates arranged at intervals, the plurality of second pole plates surrounding the first pole plate, the first pole plate and the second pole plates being connected to a detection circuit; a rotor, the second surface of the rotor having a first floating pole plate and a second floating pole plate connected, the first floating pole plate being opposite the first pole plate to form a first capacitor, the second floating pole plate being opposite the second pole plate to form a second capacitor.

[0007] In some embodiments, the orthographic projection of the first floating pole plate on the first surface is located within the orthographic projection of the first pole plate on the first surface.

[0008] In some embodiments, the orthographic projection of the second pole plate on the first surface is located within the orthographic projection of the second floating pole plate on the first surface.

[0009] In some embodiments, the number of the second electrode plates is greater than or equal to 3.

[0010] In some embodiments, the number of the second electrode plates is N, the length of the second floating electrode plate is greater than the length of one second electrode plate and less than the total length of N-1 second electrode plates in the circumferential direction of the first electrode plate.

[0011] In some embodiments, the first electrode plate is circular and the second electrode plate is fan-shaped; the first floating electrode plate is circular and the second floating electrode plate is fan-shaped.

[0012] In some embodiments, a ground wire is further arranged on the first surface, the ground wire is connected with the detection circuit, the ground wire surrounds the periphery of the first electrode plate and is located between the first electrode plate and the second electrode plate.

[0013] In some embodiments, the number of the second floating electrode plates can be 2, the two second floating electrode plates are symmetrically arranged about the center point of the first floating electrode plate, and the number of the second electrode plates is even.

[0014] In some embodiments, an insulating layer is arranged between adjacent second electrode plates.

[0015] According to some embodiments of the present application, another aspect of the embodiments of the present application further provides an angle detection method, which is performed by using the angle detection device of any one of the above embodiments, and includes: rotating the rotor relative to the stator by 360° along the rotation axis from an initial state, and obtaining a capacitance-area relationship formula corresponding to each second electrode plate and an area-angle relationship formula, the capacitance in the capacitance-area relationship formula is the capacitance between the first electrode plate and any second electrode plate, the area in the capacitance-area relationship formula and the area-angle relationship formula is the effective area directly opposite between any second electrode plate and the second floating electrode plate, and the angle in the area-angle relationship formula is the angle of rotation of the rotor relative to the initial state; obtaining a capacitance-angle relationship formula corresponding to each second electrode plate according to the capacitance-area relationship formula and the area-angle relationship formula, the capacitance in the capacitance-angle relationship formula is the capacitance between the first electrode plate and any second electrode plate, and the angle in the capacitance-angle relationship formula is the angle of rotation of the rotor relative to the initial state; obtaining a real-time capacitance between the second electrode plate and the second floating electrode plate; and obtaining a real-time rotation angle of the rotor relative to the stator along the rotation axis from the initial state by bringing the real-time capacitance into the corresponding capacitance-angle relationship formula.

[0016] The technical scheme provided by the embodiments of the present application has at least the following advantages:

[0017] The angle detection device provided by the embodiment of the present application comprises a stator and a rotor, the rotor can rotate relative to the stator around a rotation axis. The first surface of the stator has a first pole plate and a second pole plate, the second surface of the rotor has a first floating pole plate and a second floating pole plate connected to each other, the first floating pole plate and the first pole plate form a first capacitor, and the second floating pole plate and the second pole plate form a second capacitor. When the rotor rotates relative to the stator, the facing area between the first pole plate and the first floating pole plate does not change, the second floating pole plate forms different second capacitors with different second pole plates, the first pole plate and the second pole plate are connected to a detection circuit, the first capacitor and the second capacitor are connected in series to the detection circuit, the capacitance value of the first capacitor is known, and the capacitance value of the second capacitor changes. Based on the calculation formula of the series capacitors and the measured capacitance between the first pole plate and the second pole plate, the second capacitor can be calculated; the dielectric constant and the pole plate area of the second capacitor do not change, and the facing area of the second floating pole plate and the corresponding second pole plate can be calculated according to the capacitance value of the second capacitor; and the relative positions of the second floating pole plate and different second pole plates, i.e., the rotation angle of the rotor relative to the stator, can be calculated according to the facing area of the second floating pole plate and the second pole plate. Since the stator does not need to rotate, the positions of the first pole plate and the second pole plate do not change, the first pole plate and the second pole plate can be more stably connected to the detection circuit, and the rotor does not need to be connected to the detection circuit through a contact point. In this way, the stability and accuracy of the angle detection device during the rotation of the rotor relative to the stator are higher. BRIEF DESCRIPTION OF DRAWINGS

[0018] One or more embodiments are illustrated by way of example in the figures that form a part of this disclosure and which are illustrative of various embodiments of devices and methods. These examples in which the principles of the present application can be utilized, and specific embodiments thereof are shown and described herein, it being understood that the application is not intended to be limited to the particular embodiments described. Embodiments of the application can be used in conjunction with other embodiments and each of the examples provided is used as a representative of exemplary constructions for purposes of this disclosure. In the drawings, like numbers refer to like elements throughout.

[0019] FIG. 1 is a structural schematic diagram of an angle detection device according to an embodiment of the present application;

[0020] FIG. 2 is a structural schematic diagram of another angle detection device according to an embodiment of the present application;

[0021] FIG. 3 is a diagram of the relationship between the effective area of each second pole plate corresponding to different rotation angles of a second floating pole plate and the rotation angle according to an embodiment of the present application. DETAILED DESCRIPTION

[0022] As known from the background, the accuracy of shaft rotation angle detection needs to be improved.

[0023] In the related technology, the angle detection device includes a rotor and a stator, the rotor is provided with a first pole plate, the stator is provided with a second pole plate, when the rotor rotates relative to the stator, the relative area between the first pole plate and the second pole plate changes, and the facing area between the first pole plate and the second pole plate can be calculated according to the capacitance change value between the first pole plate and the second pole plate, and then the deflection angle between the first pole plate and the second pole plate, that is, the angle of rotation of the rotor relative to the stator, can be calculated.

[0024] However, the first pole plate and the second pole plate need to be connected to the corresponding detection circuit respectively, when the rotor rotates, the relative position of the first pole plate changes constantly, the first pole plate needs to be connected to the detection circuit through a contact, and the rotation of the rotor causes the contact to wear, and then the detection circuit and the first pole plate are prone to disconnection, causing the angle detection device to fail.

[0025] The embodiments of the present application provide an angle detection device and an angle detection method, which at least have the advantages of improving the accuracy and stability of the rotation angle detection.

[0026] In the description of the embodiments of the present application, the technical terms "first", "second" and the like are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0027] In this document, referring to "embodiments" means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, nor is it independent or alternative to other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0028] In the description of the embodiments of the present application, the technical terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0029] In the description of the embodiments of the present application, unless specifically defined and limited otherwise, the terms "mount", "connected", "connection", "fixed", and the like should be understood broadly, for example, can be fixed connection, can also be detachable connection, or integral; can be mechanical connection, can also be electrical connection; can be direct connection, can also be indirect connection through an intermediate medium, can be internal communication of two elements or interaction relationship between two elements. For those skilled in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0030] In the description of the embodiments of the present application, when a certain component "includes" another component, unless otherwise specified, other components are not excluded, and other components can also be further included.

[0031] The terms used in the description of various described embodiments herein are only used to describe specific embodiments, and are not intended to be limiting. As used in the description of various embodiments and the appended claims, "component" is also intended to include the plural form, unless the context clearly indicates otherwise.

[0032] The embodiments of the present application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art can understand that in the embodiments of the present application, many technical details are proposed in order to make the reader better understand the present application. However, the technical solutions claimed by the present application can be realized even without these technical details and various changes and modifications based on the following embodiments.

[0033] FIG. 1 is a structural schematic diagram of an angle detection device according to an embodiment of the present application.

[0034] Referring to FIG. 1, according to some embodiments of the present application, an angle detection device is provided, which comprises a stator 210 and a rotor 220, the rotor 220 can rotate relative to the stator 210 around a rotation axis L, the stator 210 has a first surface 231, the first surface 231 has a first pole plate 211 and a plurality of second pole plates 212 arranged at intervals, the plurality of second pole plates 212 are arranged around the first pole plate 211, and the first pole plate 211 and the second pole plates 212 are respectively connected with a detection circuit (not shown in the figure); the rotor 220 has a second surface 232, the second surface 232 has a first floating pole plate 221 and a second floating pole plate 222 connected with each other, the first floating pole plate 221 is opposite to the first pole plate 211 to form a first capacitor, and the second floating pole plate 222 is opposite to the second pole plate 212 to form a second capacitor.

[0035] The angle detection device provided by the embodiments of the present application comprises a stator 210 and a rotor 220, the rotor 220 can rotate relative to the stator 210 around a rotation axis L. The first surface 231 of the stator 210 has a first pole plate 211 and a second pole plate 212, the second surface 232 of the rotor 220 has a first floating pole plate 221 and a second floating pole plate 222 connected to each other, the first floating pole plate 221 and the first pole plate 211 form a first capacitor, and the second floating pole plate 222 and the second pole plate 212 form a second capacitor. When the rotor 220 rotates relative to the stator 210, the facing area between the first pole plate 211 and the first floating pole plate 221 does not change, the second floating pole plate 222 forms different second capacitors with different second pole plates 212, the first pole plate 211 and the second pole plate 212 are connected to a detection circuit, the first capacitor and the second capacitor are connected in series to the detection circuit, the capacitance value of the first capacitor is known, and the capacitance value of the second capacitor changes. Based on the calculation formula of the series capacitors and the measured capacitance between the first pole plate 211 and the second pole plate 212, the second capacitor can be calculated; the dielectric constant and the pole plate area of the second capacitor do not change, and the facing area of the second floating pole plate 222 and the corresponding second pole plate 212 can be calculated according to the capacitance value of the second capacitor; and the relative positions of the second floating pole plate 222 and the different second pole plates 212, i.e., the rotation angle of the rotor 220 relative to the stator 210, can be calculated according to the facing area of the second floating pole plate 222 and the second pole plate 212. Since the stator 210 does not need to rotate, the positions of the first pole plate 211 and the second pole plate 212 do not change, the first pole plate 211 and the second pole plate 212 can be more stably connected to the detection circuit, and the rotor 220 does not need to be connected to the detection circuit through a contact point, so that the stability and the accuracy of the angle detection device are higher during the rotation of the rotor 220 relative to the stator 210.

[0036] FIG. 2 is a structural diagram of another angle detection device provided by an embodiment of the present application.

[0037] In some embodiments, the orthographic projection of the first floating pole plate 221 on the first surface 231 is located in the orthographic projection of the first pole plate 211 on the first surface 231.

[0038] For example, referring to FIG. 1, the orthographic projection area of the first floating pole plate 221 can be equal to the orthographic projection area of the first pole plate 211, and the effective area of the first capacitor is the area of the first floating pole plate 221 or the area of the first pole plate 211. When the areas of the first pole plate 211 and the first floating pole plate 221 are equal, the shapes of the first pole plate 211 and the first floating pole plate 221 are the same.

[0039] Alternatively, referring to FIG. 2, the first floating plate 221 can have a smaller area than the first plate 211, and the effective area of the first capacitor can be the area of the first floating plate 221. When the area of the first plate 211 is larger than the area of the first floating plate 221, the shape of the first floating plate 221 can be different from the shape of the first plate 211.

[0040] The effective area refers to the actual area between the two plates that can store charges.

[0041] In some embodiments, the first plate can have a smaller area than the first floating plate, and the effective area of the first capacitor can be the area of the first plate. It can be understood that the first plate is spaced apart from the second plate, and when the area of the first plate is larger than the area of the first floating plate, the projection of the first floating plate does not overlap the second plate, so that the first floating plate and the second plate do not form a capacitor, and the calculation of the second capacitor is not affected.

[0042] In some embodiments, the projection of the second plate 212 on the first surface 231 is located within the projection of the second floating plate 222 on the first surface 231. That is, the area of the second plate 212 is smaller than or equal to the area of the second floating plate 222. In this way, when the second floating plate 222 is completely opposite to any second plate 212, the effective area of the second capacitor formed by the second plate 212 and the second floating plate 222 is the area of the second plate 212.

[0043] In one example, when the area of the second plate 212 is equal to the area of the second floating plate 222, the length of the second floating plate 222 is equal to the length of the second plate 212 in the circumferential direction of the first plate 211, and the width of the second floating plate 222 is equal to the width of the second plate 212 in the direction spreading from the center of the first plate 211 to the periphery, that is, the shape of the second plate 212 is the same as the shape of the second floating plate 222.

[0044] In one example, when the area of the second plate 212 is smaller than the area of the second floating plate 222, the length of the second floating plate 222 can be greater than the length of the second plate 212 in the circumferential direction of the first plate 211, and the width of the second floating plate 222 is equal to the width of the second plate 212 in the direction spreading from the center of the first plate 211 to the periphery.

[0045] In one example, when the area of the second electrode plate 212 is smaller than the area of the second floating electrode plate 222, the width of the second floating electrode plate 222 can be greater than the width of the second electrode plate 212 in a direction spreading from the center point of the first electrode plate 211 to the periphery, and the length of the second floating electrode plate 222 is equal to the length of the second electrode plate 212 in a circumferential direction of the first electrode plate 211.

[0046] In one example, when the area of the second electrode plate 212 is smaller than the area of the second floating electrode plate 222, the length of the second floating electrode plate 222 can be greater than the length of the second electrode plate 212 in the circumferential direction of the first electrode plate 211, and the width of the second floating electrode plate 222 is greater than the width of the second electrode plate 212 in the direction spreading from the center point of the first electrode plate 211 to the periphery.

[0047] When the area of the second electrode plate 212 is smaller than the area of the second floating electrode plate 222, it can be beneficial to avoid the problem of the test accuracy being reduced due to the dead zone caused by the second floating electrode plate 222 being directly opposite the second electrode plate 212. For example, when the number of second electrode plates is two and the sizes of the two second electrode plates are equal, if the area of the second floating electrode plate is equal to the area of the second electrode plate, when the second floating electrode plate is opposite any second electrode plate, whether the second floating electrode plate rotates in the clockwise direction or the counterclockwise direction, the second capacitance formed between the other second electrode plate and the second floating electrode plate will increase, and it is not possible to determine whether the rotor is rotating clockwise or counterclockwise.

[0048] In some embodiments, the number of second electrode plates 212 is greater than or equal to 3. When the number of second electrode plates 212 is at least 3, whether the second floating electrode plate 222 rotates in the clockwise direction or the counterclockwise direction, the rotation direction of the rotor 220 can be determined by the change trend of the second capacitance formed between the second floating electrode plate 222 and the corresponding second electrode plate 212. For example, when the second floating electrode plate 222 is opposite any second electrode plate 212, if the second floating electrode plate 222 rotates in the clockwise direction, the second capacitance formed between the other second electrode plate 212 located on the side of the second electrode plate 212 in the clockwise direction and the second floating electrode plate 222 increases; if the second floating electrode plate 222 rotates in the counterclockwise direction, the second capacitance formed between the other second electrode plate 212 located on the side of the second electrode plate 212 in the counterclockwise direction and the second floating electrode plate 222 increases. In addition, since there is a certain fluctuation in the distance between the second electrode plate 212 and the second floating electrode plate 222 during the rotation of the rotor 220 relative to the stator 210, setting multiple second electrode plates 212 can be beneficial to reduce the influence of distance fluctuation and improve the accuracy of the angle detection device.

[0049] In some embodiments, when the number of the second electrode plates 212 is N, the length of the second floating electrode plate 222 is greater than the length of one second electrode plate 212 and less than the total length of N-1 second electrode plates 212 in the circumferential direction of the first electrode plate 211. It can be understood that the problem of dead zone can be avoided when the length of the second floating electrode plate 222 is greater than one second electrode plate 212, and the length of the second floating electrode plate 222 also needs to be less than the total length of N-1 second electrode plates 212, that is, the second floating electrode plate 222 is not opposite to at least one second electrode plate 212 at any position, so that the position of the second floating electrode plate 222 can be determined according to at least one second electrode plate 212 that is not opposite to the second floating electrode plate 222.

[0050] In FIG. 1, the first electrode plate 211 is circular, the second electrode plate 212 is fan-shaped, the first floating electrode plate 221 is circular, and the second floating electrode plate 222 is fan-shaped. This does not constitute a limitation on the shape of the first electrode plate 211, the shape of the second electrode plate 212, the shape of the first floating electrode plate 221, and the shape of the second floating electrode plate 222. In some embodiments, the shapes of the first electrode plate and the second electrode plate can be triangular, quadrangular, or polygonal, and the shapes of the corresponding first floating electrode plate and the second floating electrode plate can be adjusted according to the shapes of the first electrode plate and the second electrode plate to meet the requirements that the first electrode plate and the first floating electrode plate can form a first capacitor, the second electrode plate and the second floating electrode plate can form a second capacitor, and the relative position of the rotor relative to the stator can be calculated according to the first capacitor and the second capacitor when the rotor rotates relative to the stator.

[0051] Referring to FIGS. 1 and 2, in some embodiments, the first surface 231 can also be provided with a ground wire 213 connected with a detection circuit (not shown in the figure), the ground wire 213 surrounds the periphery of the first electrode plate 211 and is located between the first electrode plate 211 and the second electrode plate 212. The ground wire 213 can protect the first electrode plate 211 and the second electrode plate 212, avoid the problem that a large amount of electric charge is generated in the process of static electricity discharge, and cause damage to the first electrode plate 211, the second electrode plate 212, or the detection circuit, and improve the use stability of the angle detection device.

[0052] In some embodiments, an insulating layer (not shown in the figure) can be provided between adjacent second electrode plates 212. The insulating layer can avoid the problem of electric leakage between adjacent second electrode plates 212, thereby avoiding affecting the capacitance value of the second capacitor and improving the accuracy of the angle detection device.

[0053] In the provided drawings of the present embodiment, the number of the second floating electrode plates 222 is taken as an example of 1. In some embodiments, the number of the second floating electrode plates can be 2, and the two second floating electrode plates are symmetrically arranged along the center point of the first floating electrode plate. The number of the second electrode plates is even. In this way, a structure of one first capacitor in series with two second capacitors can be formed. The two second capacitors are symmetrically arranged, and when the second floating electrode plates are opposite to the respective second electrode plates, the capacitance values of the two second capacitors are equal. According to the calculation formula of the series capacitors, the capacitance values of the two capacitors can be obtained. Then, the areas of the second electrode plates and the second floating electrode plates are calculated according to the capacitance values of the second capacitors. According to the positions of the second electrode plates, the positions of the second floating electrode plates can be determined, and then the rotation angle of the rotor relative to the stator can be obtained.

[0054] In the angle detection device provided by the present embodiment, the stator 210 and the rotor 220 are included, and the rotor 220 can rotate relative to the stator 210. The first surface 231 of the stator 210 has the first electrode plate 211 and the second electrode plate 212, and the second surface 232 of the rotor 220 has the first floating electrode plate 221 and the second floating electrode plate 222 connected thereto. The first floating electrode plate 221 and the first electrode plate 211 form a first capacitor, and the second floating electrode plate 222 and the second electrode plate 212 form a second capacitor. When the rotor 220 rotates relative to the stator 210, the opposite area between the first electrode plate 211 and the first floating electrode plate 221 does not change, and the second floating electrode plate 222 forms different second capacitors with different second electrode plates 212. The first electrode plate 211 and the second electrode plate 212 are connected to a detection circuit, and the first capacitor and the second capacitor are connected in series to the detection circuit. The capacitance value of the first capacitor is known, and the capacitance value of the second capacitor changes. Based on the calculation formula of the series capacitors, the second capacitor can be calculated, and then the opposite area of the second floating electrode plate 222 and the corresponding second electrode plate 212 can be calculated according to the capacitance value of the second capacitor. In this way, the relative position of the second floating electrode plate 222 and the second electrode plate 212, i.e., the rotation angle of the rotor 220 relative to the stator 210, can be obtained. Since the stator 210 does not need to rotate, the positions of the first electrode plate 211 and the second electrode plate 212 do not change, and the first electrode plate 211 and the second electrode plate 212 can be more stably connected to the detection circuit. The rotor 220 does not need to be connected to the detection circuit through a contact point. In this way, the stability and accuracy of the angle detection device are higher during the rotation of the rotor 220 relative to the stator 210.

[0055] According to some embodiments of the present application, another aspect of the present embodiment also provides an angle detection method, which is performed by using the angle detection device of any one of the above embodiments. The same or corresponding parts as the previous embodiment can refer to the corresponding description of the previous embodiment, which will not be described in detail below.

[0056] The angle detection method provided by the embodiments of the present application will be described below by taking the angle detection device shown in FIG. 1 as an example, and the description does not constitute a limitation on the angle detection device. When the structure of the angle detection device is adjusted, the corresponding angle detection method can be adjusted accordingly based on the angle detection method provided by the embodiments of the present application.

[0057] The angle detection method comprises the following steps.

[0058] The rotor 220 is rotated by 360° along the rotation axis L relative to the stator 210 from an initial state, wherein the initial state is the state shown in FIG. 1, and the rotation of the rotor 220 can be clockwise rotation or counterclockwise rotation. During the rotation of the rotor 220, the corresponding capacitance-area relationship and area-angle relationship of each second electrode plate 212 are obtained, wherein the capacitance in the capacitance-area relationship is the capacitance between the first electrode plate 211 and any second electrode plate 212, the area in the capacitance-area relationship and the area-angle relationship is the effective area directly opposite between any second electrode plate 212 and the second floating electrode plate 222, and the angle in the area-angle relationship is the angle of rotation of the rotor relative to the initial state.

[0059] The calculation formula of the series capacitance is Cn=C1*C2 / (C1+C2), wherein Cn is the capacitance value between the first electrode plate 211 and the second electrode plate 212, C1 is the capacitance value of the first capacitance, and C2 is the capacitance value of the second capacitance; the calculation formula of a single capacitance is ε*S / d, wherein ε is the dielectric constant, S is the effective area of the electrode plate, and d is the distance between the electrode plates.

[0060] For the first capacitance composed of the first electrode plate 211 and the first floating electrode plate 221, the dielectric constant, the effective area, and the distance between the first electrode plate 211 and the first floating electrode plate 221 do not change, and thus the capacitance value of the first capacitance is a fixed value.

[0061] For the second capacitance composed of any second electrode plate 212 and the second floating electrode plate 222, the dielectric constant and the distance between the second electrode plate 212 and the second floating electrode plate 222 do not change, and thus the effective area between the second electrode plate 212 and the second floating electrode plate 222 changes.

[0062] Therefore, the change of the capacitance between the first electrode plate 211 and the second electrode plate 212 is linearly related to the change of the second capacitance, and the change of the second capacitance is linearly related to the change of the effective area between the second electrode plate 212 and the second floating electrode plate 222. By combining the series capacitance formula and the calculation formula of the second capacitance, a capacitance-area relationship formula representing the relationship between the change of the capacitance between the first electrode plate 211 and any second electrode plate 212 and the change of the effective area between the second electrode plate 212 and the second floating electrode plate 222 can be obtained. Each capacitance between the first electrode plate 211 and each second electrode plate 212 corresponds to a respective capacitance-area relationship formula.

[0063] According to the effective area between the second floating electrode plate 222 and the second electrode plate 212 and the positional relationship between the second electrode plate 212 and other second electrode plates 212, the relative positional relationship between the second floating electrode plate 222 and the plurality of second electrode plates 212 can be obtained, i.e., the relative positional relationship between the rotor 220 and the stator 210 can be obtained. For example, when the angle is 0° as shown in FIG. 1, when the second floating electrode plate 222 rotates by 120°, the second floating electrode plate 222 is opposite to the second electrode plate 212 adjacent to the second electrode plate 212 opposite to the second floating electrode plate 222 in FIG. 1 on the clockwise (or counterclockwise) side; when the second floating electrode plate 222 rotates by 240°, the second floating electrode plate 222 is opposite to the second electrode plate 212 adjacent to the second electrode plate 212 opposite to the second floating electrode plate 222 in FIG. 1 on the counterclockwise (or clockwise) side; when the second floating electrode plate 222 is opposite to two second electrode plates 212, the two second electrode plates 212 respectively form two second capacitances. According to the detection circuit corresponding to different second electrode plates 212, the capacitance values of the two capacitances formed by the first electrode plate 211 and the two second electrode plates 212 can be obtained, and then the areas opposite to the second floating electrode plate 222 of the two second electrode plates 212 can be obtained based on the respective capacitance-area relationship formulas. Based on the opposite areas of different second electrode plates 212 and the second floating electrode plate 222, the relative positional relationship between the second floating electrode plate 222 and different second electrode plates 212 can be calculated, and then the relative positional relationship between the rotor 220 and the stator 210, i.e., the rotation angle of the rotor 220, can be obtained.

[0064] Further, by combining the capacitance-area relationship formula and the area-angle relationship formula, a capacitance-angle relationship formula corresponding to each second electrode plate 212 can be obtained. The first electrode plate 211 and each second electrode plate 212 respectively correspond to a capacitance-area relationship formula, and by combining the capacitance-area relationship formula and the area-angle relationship formula, the capacitance values corresponding to the capacitances formed by the first electrode plate 211 and different second electrode plates 212 in different position states of the rotor 220 within a rotation range of 360° can be obtained.

[0065] In the application process of the angle detection device, when the rotor 220 rotates relative to the stator 210, the capacitance between the first plate 211 and different second plates 212 can be obtained, and then the real-time capacitance between the second plate 212 and the second floating plate 222 can be obtained according to the calculation formula of the series capacitance; the real-time capacitance is brought into the above-mentioned capacitance-angle relationship, and the effective area of the second floating plate 222 and different second plates 212 can be obtained, and the relative position relationship between the second floating plate 222 and the second plate 212 can be calculated according to the facing area of the second plate 212 and the second floating plate 222, that is, the real-time rotation angle of the rotor 220 relative to the stator 210 along the rotation axis L from the initial state.

[0066] FIG. 3 is a diagram of the change relationship between the effective area corresponding to each second plate and the rotation angle of the second floating plate at different rotation angles according to an embodiment of the present application.

[0067] In some embodiments, before the real-time capacitance is brought into the above-mentioned capacitance-angle relationship, it can further include: judging the interval in which the second floating plate 222 is located, and the interval is represented as the angle range of the rotation of the second floating plate 222 in the initial state.

[0068] For example, when the number of second plates 212 is 3, the second plate 212 facing the second floating plate 222 in the state shown in FIG. 1 is Rx1, and the capacitance value of the second capacitance formed between Rx1 and the first plate 211 is Ca; after the second floating plate 222 rotates clockwise by 120° in the state shown in FIG. 1, the second plate 212 facing the second floating plate 222 is Rx2, and the capacitance value of the second capacitance formed between Rx2 and the first plate 211 is Cb; after the second floating plate 222 rotates clockwise by 240° in the state shown in FIG. 1, the second plate 212 facing the second floating plate 222 is Rx3, and the capacitance value of the second capacitance formed between Rx3 and the first plate 211 is Cc.

[0069] X=(Ca+Cb) / (Ca+Cb+Cc), Y=(Cb+Cc) / (Ca+Cb+Cc), and Z=(Ca+Cc) / (Ca+Cb+Cc) are calculated respectively, and the number closest to 1 in X, Y, and Z is judged. In combination with reference to FIG. 3, when X is closest to 1, it can be judged that the second floating plate 222 rotates in the interval of 0°-120°; when Y is closest to 1, it can be judged that the second floating plate 222 rotates in the interval of 120°-240°; and when Z is closest to 1, it can be judged that the second floating plate 222 rotates in the interval of 240°-360°. Through the above-mentioned way, the interval in which the second floating plate 222 is located is preliminarily judged, and then the real-time capacitance obtained by the detection circuit is calculated, so that the position of the second floating plate 222 can be obtained more quickly.

[0070] In the angle detection method provided by the embodiments of the present application, the first floating electrode plate 221 and the first electrode plate 211 form a first capacitor, and the second floating electrode plate 222 and the second electrode plate 212 form a second capacitor, thereby forming a series capacitor. When the rotor 220 rotates relative to the stator 210, the facing area between the first electrode plate 211 and the first floating electrode plate 221 does not change, and the capacitance of the first capacitor is a fixed value. The second floating electrode plate 222 forms different second capacitors with different second electrode plates 212. The capacitance change between the first electrode plate 211 and the second electrode plate 212 is linearly related to the change of the second capacitor, and the change of the second capacitor is linearly related to the change of the effective area between the second electrode plate 212 and the second floating electrode plate 222. By combining the formula of the series capacitor and the calculation formula of the second capacitor, a capacitance-area relationship formula representing the relationship between the capacitance change between the first electrode plate 211 and any second electrode plate 212 and the change of the effective area between the second electrode plate 212 and the second floating electrode plate 222 can be obtained. The capacitor formed by each second electrode plate 212 and the first electrode plate 211 corresponds to a respective capacitance-area relationship formula. Based on the facing areas of different second electrode plates 212 and the second floating electrode plate 222, the relative positional relationship between the second floating electrode plate 222 and different second electrode plates 212 can be calculated, and the relative positional relationship between the rotor 220 and the stator 210, i.e., the rotation angle of the rotor 220, can be obtained.

[0071] Those skilled in the art can understand that the above-mentioned embodiments are specific embodiments for implementing the present application, and in actual applications, various changes can be made in form and details without departing from the spirit and scope of the present application. Any person skilled in the art can make various modifications and changes without departing from the spirit and scope of the present application, and therefore the protection scope of the present application should be limited by the scope defined in the claims.

Claims

1.An angle detection device, comprising: a stator, a first surface of the stator having a first pole plate and a plurality of second pole plates arranged at intervals, the plurality of second pole plates being arranged around the first pole plate, the first pole plate and the second pole plates being connected with a detection circuit; and a rotor, a second surface of the rotor having a first floating pole plate and a second floating pole plate connected, the first floating pole plate being opposite to the first pole plate to form a first capacitor, the second floating pole plate being opposite to the second pole plate to form a second capacitor; wherein a projection of the first floating pole plate on the first surface is located within a projection of the first pole plate on the first surface; wherein a projection of the second pole plate on the first surface is located within a projection of the second floating pole plate on the first surface; wherein the number of the second pole plates is greater than or equal to 3; wherein the number of the second pole plates is N, a length of the second floating pole plate is greater than a length of one of the second pole plates, and the length of the second floating pole plate is less than a total length of N-1 of the second pole plates in a circumferential direction of the first pole plate; wherein the first pole plate is circular, and the second pole plates are fan-shaped; wherein the first floating pole plate is circular, and the second floating pole plate is fan-shaped; wherein a ground wire is arranged on the first surface, the ground wire being connected with the detection circuit, the ground wire being arranged around the first pole plate and between the first pole plate and the second pole plates; wherein the number of the second floating pole plates can be 2, the two second floating pole plates being arranged symmetrically about a center point of the first floating pole plate, and the number of the second pole plates is even; wherein an insulating layer is arranged between adjacent second pole plates. 10.An angle detection method, comprising: rotating a rotor relative to a stator along an axis of rotation by 360° from an initial state, and obtaining a capacitance-area relationship and an area-angle relationship corresponding to each second pole plate, the capacitance in the capacitance-area relationship being a capacitance between the first pole plate and any one of the second pole plates, the area in the capacitance-area relationship and the area-angle relationship being an effective area opposite between any one of the second pole plates and the second floating pole plate, the angle in the area-angle relationship being an angle of rotation of the rotor relative to the initial state; obtaining a capacitance-angle relationship corresponding to each second pole plate according to the capacitance-area relationship and the area-angle relationship, the capacitance in the capacitance-angle relationship being a capacitance between the first pole plate and any one of the second pole plates, the angle in the capacitance-angle relationship being an angle of rotation of the rotor relative to the initial state; obtaining a real-time capacitance between the second pole plate and the second floating pole plate; and obtaining a real-time rotation angle of the rotor relative to the stator along the axis of rotation from the initial state by bringing the real-time capacitance into the corresponding capacitance-angle relationship. ​ 2. The angle detection device according to claim 1, wherein ​ 3. The angle detection device according to claim 1, wherein ​ 4. The angle detection device according to claim 1, wherein ​ 5. The angle detection device according to claim 4, wherein ​ 6. The angle detection device according to claim 1, wherein ​ 7. The angle detection apparatus according to claim 1, wherein ​ 8. The angle detection apparatus according to claim 1, wherein ​ 9. The angle detection apparatus according to claim 1, wherein ​ ​ ​ ​ ​ ​

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