Angle detection device and angle detection method

Abstract

Embodiments of the present application relate to the technical field of angle measuring devices and provide an angle detection device and an angle detection method. The angle detection device comprises a stator and a rotor. The first surface of the stator is provided with a first electrode plate and a plurality of second electrode plates arranged at intervals, the plurality of second electrode plates arranged surrounding the first electrode plate, and the first electrode plate and the second electrode plates are connected to a detection circuit. The second surface of the rotor is provided with a first floating electrode plate and a second floating electrode plate connected to each other, the first floating electrode plate facing the first electrode plate to constitute a first capacitor, and the second floating electrode plate facing the second electrode plate to constitute a second capacitor. According to the embodiment of the present application, the accuracy and stability of rotation angle detection can be improved.

Description

Technical Field

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[0006] According to some embodiments of the present application, one embodiment of the present application provides an angle detection device. The angle detection device comprises a stator and a rotor, the first surface of the stator is provided with a first electrode plate and a plurality of second electrode plates arranged at intervals, the plurality of second electrode plates are arranged surrounding the first electrode plate, the first electrode plate and the second electrode plates are connected to a detection circuit, the second surface of the rotor is provided with a first floating electrode plate and a second floating electrode plate connected to each other, the first floating electrode plate facing the first electrode plate constitutes a first capacitor, and the second floating electrode plate facing the second electrode plate constitutes a second capacitor.

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

[0008] In some embodiments, the orthographic projection of the second electrode plate on the first surface lies within the orthographic projection of the second floating electrode plate on the first surface.

[0009] In some embodiments, the number of second electrode plates is three or more.

[0010] In some embodiments, the number of second electrodes is N, and in the direction along the circumferential direction of the first electrode, the length of the second floating electrode is longer than the length of one second electrode, while the length of the second floating electrode is shorter than the total length of N-1 second electrodes.

[0011] In some embodiments, the first electrode plate is circular, 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, an earth wire is further provided on the first surface, the earth wire is connected to a detection circuit, and the earth wire is arranged to surround the first electrode plate and is located between the first electrode plate and the second electrode plate.

[0013] In some embodiments, the number of second floating electrode plates may be two, and the two second floating electrode plates are arranged symmetrically with respect to the center point of the first floating electrode plate, and the number of second electrode plates is even.

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

[0015] According to some embodiments of the present application, another embodiment of the present application further provides an angle detection method to be performed using any of the angle detection devices of the above embodiments. In this angle detection method, the rotor is rotated 360° around the axis of rotation from an initial state relative to the stator, and a corresponding capacity-area relationship and area-angle relationship are obtained for each second electrode plate, where the capacity in the capacity-area relationship is the capacity between the first electrode plate and any of the second electrode plates, the area in the capacity-area relationship and area-angle relationship is the direct effective area between any of the second electrode plates and the second floating electrode plate, and the angle in the area-angle relationship is the angle by which the rotor has rotated from the initial state. - An angle relationship is used to obtain a capacitance-angle relationship for each second plate, where the capacitance in the capacitance-angle relationship is the capacitance between the first plate and any of the second plates, and the angle in the capacitance-angle relationship is the angle of rotation of the rotor from its initial state. The real-time capacitance between the second plate and the second floating plate is obtained, and by introducing the real-time capacitance into the corresponding capacitance-angle relationship, the real-time rotation angle of the rotor around the axis of rotation from its initial state relative to the stator is obtained.

[0016] The technical proposal according to the embodiments of this application has at least the following advantages.

[0017] The angle detection device according to the embodiment of the present invention comprises a stator and a rotor rotatable around a rotation axis relative to the stator. The first surface of the stator is provided with a first electrode plate and a second electrode plate, and the second surface of the rotor is provided with a first floating electrode plate and a second floating electrode plate connected to each other. The first floating electrode plate and the first electrode plate constitute a first capacitor, and the second floating electrode plate and the second electrode plate constitute a second capacitor. When the rotor rotates relative to the stator, the facing area between the first electrode plate and the first floating electrode plate does not change, but the second floating electrode plate constitutes a different second electrode plate and a different second capacitor. The first electrode plate and the second electrode plate 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, while the capacitance value of the second capacitor changes. The capacitance value of the second capacitor can be calculated from the series capacitance calculation formula and the measured capacitance between the first electrode plate and the second electrode plate. Since the dielectric constant and plate area of ​​the second capacitor do not change, the direct facing area of ​​the second floating plate and the corresponding second plate can be calculated from the capacitance value of the second capacitor. Furthermore, from the direct facing area of ​​the second floating plate and the second plate, the relative position of the second plate different from the second floating plate, i.e., the rotation angle of the rotor relative to the stator, can be calculated. Since the stator does not rotate, the positions of the first and second plates do not change, so the first and second plates can be connected to the detection circuit more stably. Also, since it is not necessary to connect the rotor to the detection circuit via a contact point, the stability and accuracy of the angle detection device during the rotor's rotation relative to the stator are high. [Brief explanation of the drawing]

[0018] One or more embodiments are illustrated through corresponding drawings, but these illustrative descriptions are not limiting to the embodiments, and unless otherwise specified, the proportion of drawings is not limited. To more clearly explain the embodiments of the present application or the prior art, the drawings necessary for the embodiments are briefly described below. Note that the drawings in the following description are only some embodiments of the present application, and it will be obvious to those skilled in the art that other drawings can be obtained from these drawings without inventive effort.

[0019] [Figure 1] FIG. 1 is a diagram showing the configuration of an angle detection device according to an embodiment of the present application.

[0020] [Figure 2] FIG. 2 is a diagram showing the configuration of another angle detection device according to an embodiment of the present application.

[0021] [Figure 3] FIG. 3 is a diagram showing the relationship between the effective area and the rotation angle of each second floating electrode plate with respect to the second electrode plate at different rotation angles according to an embodiment of the present application.

MODE FOR CARRYING OUT THE INVENTION

[0022] As can be seen from the background art, there is room for improvement in the accuracy of detecting the rotation angle around the axis.

[0023] In the related art, an angle detection device includes a rotor and a stator. A first electrode plate is provided on the rotor, and a second electrode plate is provided on the stator. When the rotor rotates relative to the stator via a rotating shaft, the relative area between the first electrode plate and the second electrode plate changes. Therefore, from the change value of the capacitance between the first electrode plate and the second electrode plate, the facing area between the first electrode plate and the second electrode plate can be calculated. Further, the deviation angle between the first electrode plate and the second electrode plate, that is, the rotation angle of the rotor with respect to the stator can be calculated.

[0024] However, the first electrode plate and the second electrode plate need to be connected to the corresponding detection circuits respectively. When the rotor rotates, the relative position of the first electrode plate changes. Since the first electrode plate is connected to the detection circuit via a contact point, wear occurs at the contact point due to the rotation of the rotor, and furthermore, the problem that the connection between the detection circuit and the first electrode plate is easily disconnected occurs, which causes a failure of the angle detection device.

[0025] According to the embodiment of the present application, an angle detection device and an angle detection method capable of improving at least the accuracy and stability of rotation angle detection can be provided.

[0026] In the description of the embodiments of this application, technical terms such as "first," "second," etc., are used to distinguish different subjects and do not express or imply relative importance, nor do they imply the number of technical features, a specific order, or a primary / secondary relationship. In the description of the embodiments of this application, "multiple" means two or more unless otherwise clearly and specifically limited.

[0027] Where the term “Examples” is used herein, it means that the specific features, configurations, or characteristics described using the Examples are included in at least one Example of the Application. Where this term is used in different parts of the Specification, it does not necessarily refer to the same Example, nor is it intended to limit any example to one that is mutually exclusive or alternative to the other Examples. It will be obvious to those skilled in the art that the Examples described herein may be combined with other Examples.

[0028] In the description of the embodiments of this application, the directions or positional relationships expressed using technical terms such as "center," "vertical direction," "horizontal direction," "length," "width," "thickness," "top," "bottom," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," "outside," "clockwise direction," "counterclockwise direction," "axial direction," "radial direction," and "circumferential direction" are based on the drawings and are merely for the convenience and simplification of describing the embodiments of this application. They do not necessarily express or imply that the device or element in question has a specific direction or is configured or operated in a specific direction, and therefore do not limit the embodiments of this application.

[0029] In the description of the embodiments of this application, unless otherwise explicitly specified and limited, technical terms such as "attachment," "connection," "bonding," and "fixing" should be understood in a broad sense. For example, it may be a fixed connection, a removable connection, or an integral connection. It may also be a mechanical connection or an electrical connection. It may also be a direct connection or an indirect connection via an intermediate object. The interiors of the two elements may be in communication, or the two elements may interact with each other. A person skilled in the art will be able to understand the specific meaning of the above terms in the embodiments of this application depending on the specific situation.

[0030] In the description of the embodiments of this application, when one component "includes" another component, unless otherwise specified, this does not exclude the other component, and it may include yet another component.

[0031] In this specification, the terms used to describe each embodiment are used only to describe that particular embodiment, but are not intended to be limiting. For example, the term “member” as used in the description of each embodiment and in the claims includes the plural form unless otherwise specified.

[0032] The embodiments of this application will be described in detail below with reference to the drawings. However, as those skilled in the art will see, although many technical details are described in each embodiment of this application to help the reader better understand it, the technical invention protected by this application can be realized without these technical details or the various changes and modifications based on the embodiments below.

[0033] Figure 1 shows the configuration of an angle detection device according to one embodiment of the present invention.

[0034] As shown in Figure 1, according to a partial embodiment of the present application, one embodiment of the present application provides an angle detection device. The angle detection device comprises a stator 210 and a rotor 220 that is rotatable about a rotation axis L relative to the stator 210. The first surface 231 of the stator 210 is provided with a first electrode plate 211 and a plurality of second electrode plates 212 arranged at intervals, the plurality of second electrode plates 212 arranged to surround the first electrode plate 211, and the first electrode plate 211 and the second electrode plates 212 are each connected to a detection circuit (not shown). The second surface 232 of the rotor 220 is provided with a first floating electrode 221 and a second floating electrode 222 that are connected to each other. The first floating electrode 221 faces the first electrode 211 to form a first capacitor, and the second floating electrode 222 faces the second electrode 212 to form a second capacitor.

[0035] An angle detection device according to an embodiment of the present invention comprises a stator 210 and a rotor 220 rotatable around a rotation axis L relative to the stator 210. The first surface 231 of the stator 210 is provided with a first electrode plate 211 and a second electrode plate 212, and the second surface 232 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 and the first electrode plate 211 constitute a first capacitor, and the second floating electrode plate 222 and the second electrode plate 212 constitute a second 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, but the second floating electrode plate 222 constitutes a different second capacitor with a different second electrode plate 212. The first plate 211 and the second 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, while the capacitance value of the second capacitor changes. The capacitance of the second capacitor can be calculated from the series capacitance calculation formula and the measured capacitance between the first plate 211 and the second plate 212. Since the dielectric constant and plate area of ​​the second capacitor do not change, the direct facing area of ​​the second floating plate 222 and the corresponding second plate 212 can be calculated from the capacitance value of the second capacitor. Furthermore, from the direct facing area of ​​the second floating plate 222 and the second plate 212, the relative position of the second plate 212 that is different from the second floating plate 222, i.e., the rotation angle of the rotor 220 relative to the stator 210, can be calculated. Since the stator 210 does not rotate, the positions of the first pole plate 211 and the second pole plate 212 do not change. Therefore, the first pole plate 211 and the second pole plate 212 can be connected to the detection circuit more stably. Furthermore, since it is not necessary to connect the rotor 220 to the detection circuit via a contact point, the stability and accuracy of the angle detection device during the rotation of the rotor 220 relative to the stator 210 are high.

[0036] Figure 2 shows the configuration of another angle detection device according to one embodiment of the present invention.

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

[0038] For example, as shown in Figure 1, the orthographic area of ​​the first floating electrode plate 221 can be made the same as the orthographic area of ​​the first electrode plate 211. In this case, the effective area of ​​the first capacitor is the area of ​​the first floating electrode plate 221 or the area of ​​the first electrode plate 211. When the areas of the first electrode plate 211 and the first floating electrode plate 221 are the same, the shapes of the first electrode plate 211 and the first floating electrode plate 221 are the same.

[0039] Alternatively, as shown in Figure 2, the orthographic area of ​​the first floating electrode plate 221 can be made smaller than the orthographic area of ​​the first electrode plate 211, in which case the effective area of ​​the first capacitor is the area of ​​the first floating electrode plate 221. If the area of ​​the first electrode plate 211 is larger than the area of ​​the first floating electrode plate 221, the shape of the first floating electrode plate 221 can be different from the shape of the first electrode plate 211.

[0040] Here, effective area refers to the actual area between the two plates where charge can be stored.

[0041] In some embodiments, the orthographic area of ​​the first electrode plate can be made smaller than the orthographic area of ​​the first floating electrode plate. In this case, the effective area of ​​the first capacitor is the area of ​​the first electrode plate. Furthermore, since the first electrode plate and the second electrode plate are spaced apart, if the orthographic area of ​​the first electrode plate is larger than the orthographic area of ​​the first floating electrode plate, the orthographic projection of the first floating electrode plate does not superimpose onto the second electrode plate. This suppresses the formation of a capacitor between the first floating electrode plate and the second electrode plate, preventing the calculation of the capacitance of the second capacitor from being affected.

[0042] In some embodiments, the orthographic projection of one second electrode plate 212 on the first surface 231 lies within the orthographic projection of the second floating electrode plate 222 onto the first surface 231. That is, the area of ​​the second electrode plate 212 is less than or equal to the area of ​​the second floating electrode plate 222. In this case, if the second floating electrode plate 222 is perfectly aligned with one of the second electrode plates 212, the effective area of ​​the second capacitor composed of this second electrode plate 212 and the second floating electrode plate 222 is the area of ​​the second electrode plate 212.

[0043] In one example, if the area of ​​the second electrode plate 212 is the same as the area of ​​the second floating electrode plate 222, then in the direction along the circumferential direction of the first electrode plate 211, the length of the second floating electrode plate 222 is the same as the length of the second electrode plate 212, and in the direction extending outward from the center point of the first electrode plate 211, the width of the second floating electrode plate 222 is the same as the width of the second electrode plate 212. In other words, the shape of the second electrode plate 212 is the same as that of the second floating electrode plate 222.

[0044] In one example, if 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 may be longer than the length of the second electrode plate 212 in the direction along the circumferential direction of the first electrode plate 211, and the width of the second floating electrode plate 222 may be the same as the width of the second electrode plate 212 in the direction extending outward from the center point of the first electrode plate 211.

[0045] In one example, if 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 may be greater than the width of the second electrode plate 212 in the direction extending outward from the center point of the first electrode plate 211, and the length of the second floating electrode plate 222 may be the same as the length of the second electrode plate 212 in the direction along the circumferential direction of the first electrode plate 211.

[0046] In one example, if 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 may be longer than the length of the second electrode plate 212 in the direction along the circumferential direction of the first electrode plate 211, and the width of the second floating electrode plate 222 may be greater than the width of the second electrode plate 212 in the direction extending outward from the center point of the first electrode plate 211.

[0047] Furthermore, if the area of ​​the second electrode plate 212 is made smaller than the area of ​​the second floating electrode plate 222, the second floating electrode plate 222 and the second electrode plate 212 will be directly facing each other, causing a dead band and thus avoiding the problem of reduced detection accuracy. For example, if there are two second electrode plates and the two second electrode plates are the same size, and assuming that the area of ​​the second floating electrode plate is the same as the area of ​​the second electrode plate, when the second floating electrode plate is directly facing either of the second electrode plates, regardless of whether the second floating electrode plate rotates clockwise or counterclockwise, the capacitance value of the second capacitor formed between the other second electrode plate and the second floating electrode plate increases, making it impossible to determine whether the rotor rotated clockwise or counterclockwise.

[0048] In some embodiments, the number of second electrodes 212 is three or more. When there are at least three second electrodes 212, the rotation direction of the rotor 220 can be determined based on the trend of change in the capacitance of the second capacitor formed between the second floating electrode 222 and the corresponding second electrode 212, regardless of whether the second floating electrode 222 rotates clockwise or counterclockwise. For example, if the second floating electrode 222 is directly facing one of the second electrodes 212, when the second floating electrode 222 rotates clockwise, the capacitance value of the second capacitor formed by the second floating electrode 222 and another second electrode 212 located on the clockwise side of the second electrode 212 increases. Also, when the second floating electrode 222 rotates counterclockwise, the capacitance value of the second capacitor formed by the second floating electrode 222 and another second electrode 212 located on the counterclockwise side of the second electrode 212 increases. Although there is a certain variation 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, by providing multiple second electrode plates 212, the effect of the distance variation can be reduced, thereby improving the accuracy of the angle detection device.

[0049] In some embodiments, when the number of second electrodes 212 is N, the length of the second floating electrode 222 is longer than the length of one second electrode 212 in the direction along the circumferential direction of the first electrode 211, and the length of the second floating electrode 222 is shorter than the total length of N-1 second electrodes 212. In this way, when the length of the second floating electrode 222 is longer than the length of one second electrode 212, the problem of dead band formation can be avoided. Furthermore, the length of the second floating electrode 222 must be shorter than the total length of N-1 second electrodes 212, meaning that the second floating electrode 222 must not be directly facing at least one second electrode 212 at any position. In this way, the position of the second floating electrode 222 can be determined based on the position of at least one second electrode 212 that is not directly facing the second floating electrode 222.

[0050] In the example shown in Figure 1, the first electrode plate 211 is circular and the second electrode plate 212 is fan-shaped, and the first floating electrode plate 221 is circular and the second floating electrode plate 222 is fan-shaped, but the shapes of the first electrode plate 211, the second electrode plate 212, the first floating electrode plate 221 and the second floating electrode plate 222 are not limited. In some embodiments, the shapes of the first electrode plate and the second electrode plate may be triangular, quadrilateral or polygonal, and the shapes of the first and second floating electrode plates can be adjusted according to the shapes of the first and second electrode plates so that the first electrode plate and the first floating electrode plate constitute a first capacitor and the second electrode plate and the second floating electrode plate constitute a second capacitor, and it is sufficient that the relative position of the rotor with respect to the stator can be calculated based on the capacitances of the first capacitor and the second capacitor when the rotor rotates with respect to the stator.

[0051] As shown in Figures 1 and 2, in some embodiments, a ground wire 213 may be further provided on the first surface 231. The ground wire 213 is connected to a detection circuit (not shown), is arranged to surround the first electrode plate 211, and is located between the first electrode plate 211 and the second electrode plate 212. The ground wire 213 protects the first electrode plate 211 and the second electrode plate 212, preventing damage to the first electrode plate 211 and the second electrode plate 212, or to the detection circuit, due to the generation of a large amount of charge during electrostatic discharge, thereby improving the operational stability of the angle detection device.

[0052] In some embodiments, an insulating layer (not shown) may be provided between adjacent second electrode plates 212. The insulating layer prevents leakage current from occurring between adjacent second electrode plates 212, suppresses the influence on the capacitance value of the second capacitor, and improves the accuracy of the angle detection device.

[0053] In the drawings of this embodiment, the number of second floating plates 222 is shown as one, for example. In some embodiments, the number of second floating plates can be two, and the two second floating plates are arranged symmetrically with respect to the center point of the first floating plate, and the number of second plates is even. In this way, one first capacitor and two second capacitors are connected in series, and the two second capacitors are arranged symmetrically. When the second floating plates face each other, the capacitance values ​​of the two second capacitors are the same. The capacitance values ​​of the two capacitors can also be obtained using the series capacitance calculation formula, and furthermore, the area of ​​the second plate and the second floating plate can be calculated from the capacitance values ​​of the second capacitors, the position of the second floating plate can be determined based on the position of the second plate, and the rotation angle of the rotor relative to the stator can be obtained.

[0054] An angle detection device according to an embodiment of the present invention comprises a stator 210 and a rotor 220 rotatable relative to the stator 210. The first surface 231 of the stator 210 is provided with a first electrode plate 211 and a second electrode plate 212, and the second surface 232 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 and the first electrode plate 211 constitute a first capacitor, and the second floating electrode plate 222 and the second electrode plate 212 constitute a second 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, but the second floating electrode plate 222 constitutes a different second capacitor from a different second electrode plate 212. The first electrode plate 211 and the second electrode plate 212 are connected to the 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, while the capacitance value of the second capacitor changes. The capacitance value of the second capacitor can be calculated using the series capacitance calculation formula. Furthermore, from the capacitance value of the second capacitor, the area of ​​the second floating electrode plate 222 and the corresponding second electrode plate 212 can be calculated. This allows us to obtain 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. Since the stator 210 does not rotate, the positions of the first electrode plate 211 and the second electrode plate 212 do not change. Therefore, the first electrode plate 211 and the second electrode plate 212 can be connected to the detection circuit more stably. Furthermore, since the rotor 220 does not need to be connected to the detection circuit via a contact point, the angle detection device has high stability and accuracy during the rotation of the rotor 220 relative to the stator 210.

[0055] According to some embodiments of the present application, other embodiments of the present application further provide an angle detection method that is performed using any of the angle detection devices of the above embodiments. For parts that are the same as or corresponding to the previous embodiments, refer to the description of the corresponding parts of the embodiments described above, and a detailed description is omitted below.

[0056] In the following, the angle detection method according to the embodiment of the present application will be described using the angle detection device shown in Figure 1 as an example. However, this does not limit the angle detection method, and if the configuration of the angle detection device is adjusted, the corresponding angle detection method can also be adjusted according to the angle detection device according to the embodiment of the present application.

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

[0058] The rotor 220 is rotated 360° around the rotation axis L relative to the stator 210 from its initial state. Here, the initial state is the state shown in Figure 1, and the rotation of the rotor 220 can be either clockwise or counterclockwise. During the rotation of the rotor 220, a "capacity-area relationship" and an "area-angle relationship" corresponding to each second electrode plate 212 are obtained. Here, the capacity in the capacity-area relationship is the capacity between the first electrode plate 211 and any of the second electrode plates 212, the area in the capacity-area relationship and area-angle relationship is the effective area where any of the second electrode plates 212 and the second floating electrode plate 222 face each other directly, and the angle in the area-angle relationship is the angle by which the rotor has rotated from its initial state.

[0059] It is known that the formula for calculating series capacitance is Cn = C1 * C2 / (C1 + C2), where Cn is the capacitance value between the first plate 211 and the second plate 212, C1 is the capacitance value of the first capacitor, and C2 is the capacitance value of the second capacitor. Also, in the formula for calculating a single capacitor, ε is the dielectric constant, S is the effective facing area of ​​the plates, and d is the distance between the plates.

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

[0061] Furthermore, for a second capacitor composed of either the second electrode plate 212 and the second floating electrode plate 222, the dielectric constant and the distance between the plates do not change, but the effective area between the second electrode plate 212 and the second floating electrode plate 222 changes.

[0062] Therefore, the change in capacitance between the first plate 211 and the second plate 212 is linearly correlated with the change in capacitance of the second capacitor, and the change in capacitance of the second capacitor is linearly correlated with the change in effective area between the second plate 212 and the second floating plate 222. Using the formula for series capacitance and the formula for the capacitance of the second capacitor, a capacitance-area relationship can be obtained that expresses the relationship between the change in capacitance between the first plate 211 and any of the second plates 212 and the change in effective area where the second plate 212 and the second floating plate 222 face each other. The capacitance of each capacitor composed of each second plate 212 and first plate 211 can be associated with the respective capacitance-area relationship.

[0063] From the effective facing area between one second electrode plate 212 and the second floating electrode plate 222, and the positional relationship between the said second electrode plate 212 and other second electrode plates 212, the relative positional relationship between the second floating electrode plate 222 and the multiple second electrode plates 212, i.e., the relative positional relationship between the rotor 220 and the stator 210, can be obtained. For example, if the angle shown in Figure 1 is set to 0°, when the second floating electrode plate 222 rotates 120°, the second floating electrode plate 222 will face the second electrode plate 212 adjacent to the second electrode plate 212 facing directly in Figure 1, on the clockwise (or counterclockwise) side. Also, when the second floating electrode plate 222 rotates 240°, the second floating electrode plate 222 will face the second electrode plate 212 adjacent to the second electrode plate 212 facing directly in Figure 1, on the counterclockwise (or clockwise) side. When the second floating electrode plate 222 faces the two second electrodes 212, the two second electrodes 212 each constitute two second capacitors. The capacitance values ​​of the two capacitors formed by the first electrode plate 211 and the two second electrodes 212 can be obtained by the detection circuits corresponding to the different second electrodes 212. Furthermore, the facing area of ​​the two second electrodes 212 and the second floating electrode plate 222 can be obtained using the respective capacitance-area relationship formulas. From the facing areas of the different second electrodes 212 and the second floating electrode plate 222, the relative positional relationship between the second floating electrode plate 222 and the different second electrodes 212 can be calculated, and furthermore, 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] Furthermore, a capacitance-angle relationship can be obtained for each second electrode plate 212 using the capacitance-area relationship and the area-angle relationship. A capacitance-area relationship is associated between the first electrode plate 211 and each second electrode plate 212, and the capacitance-area relationship and the area-angle relationship can be used to obtain the capacitance value corresponding to the capacitor composed of the first electrode plate 211 and different second electrode plates 212 when the rotor 220 is in different positions within a 360° rotation range.

[0065] When applying the angle detection device, as the rotor 220 rotates relative to the stator 210, the capacitance between the first electrode plate 211 and the second electrode plate 212, which is different from the first electrode plate 211, can be obtained. Furthermore, the real-time capacitance between the second electrode plate 212 and the second floating electrode plate 222 can be obtained using the series capacitance calculation formula. By introducing the real-time capacitance into the above capacitance-angle relationship formula, the effective area of ​​the second electrode plate 212, which is different from the second floating electrode plate 222, can be obtained. From the direct facing area of ​​the second electrode plate 212 and the second floating electrode plate 222, the relative positional relationship between the second floating electrode plate 222 and the second electrode plate 212, that is, the real-time rotation angle of the rotor 220 rotating around the rotation axis L from the initial state relative to the stator 210, can be calculated.

[0066] Figure 3 shows the relationship between the effective area and the change in rotation angle for each second floating electrode plate at different rotation angles in one embodiment of the present invention.

[0067] In some embodiments, before introducing real-time capacitance into the capacitance-angle relationship described above, the interval in which the second floating electrode plate 222 is located may be determined, where the interval represents the angular range of rotation of the second floating electrode plate 222 from its initial state.

[0068] For example, if there are three second plates 212, let Rxl be the second plate 212 that is directly facing the second floating plate 222 in the state shown in Figure 1, and let Ca be the capacitance value of the second capacitor composed of Rx1 and the first plate 211; rotate the second floating plate 222 120° clockwise from the state shown in Figure 1, then let Rx2 be the second plate 212 that is directly facing the second floating plate 222, and let Cb be the capacitance value of the second capacitor composed of Rx2 and the first plate 211; rotate the second floating plate 222 240° clockwise from the state shown in Figure 1, then let Rx3 be the second plate 212 that is directly facing the second floating plate 222, and let Cc be the capacitance value of the second capacitor composed of Rx3 and the first plate 211.

[0069] X=(Ca+Cb) / (Ca+Cb+Cc), Y=(Cb+Cc) / (Ca+Cb+Cc), and Z=(Ca+Cc) / (Ca+Cb+Cc) are calculated, and the value closest to 1 among X, Y, and Z is determined. Combining this with Figure 3, if X is closest to 1, it can be determined that the second floating electrode plate 222 is rotating within the range of 0° to 120°. If Y is closest to 1, it can be determined that the second floating electrode plate 222 is rotating within the range of 120° to 240°. If Z is closest to 1, it can be determined that the second floating electrode plate 222 is rotating within the range of 240° to 360°. By first determining the range in which the second floating electrode plate 222 is located using the above method, and then further calculating by combining this with the real-time capacitance acquired by the detection circuit, the location of the second floating electrode plate 222 can be obtained more quickly.

[0070] In the angle detection method according to the embodiment of the present invention, a series capacitance is formed by a first capacitor composed of a first floating electrode plate 221 and a first electrode plate 211, and a second capacitor composed of a second floating electrode plate 222 and a second electrode plate 212. When the rotor 220 rotates relative to the stator 210, the area between the first electrode plate 211 and the first floating electrode plate 221 does not change, so the capacitance value of the first capacitor is fixed. The second floating electrode plate 222 constitutes a different second capacitor from a different second electrode plate 212. The change in capacitance between the first electrode plate 211 and the second electrode plate 212 is linearly correlated with the change in capacitance of the second capacitor, and the change in capacitance of the second capacitor is linearly correlated with the change in effective area between the second electrode plate 212 and the second floating electrode plate 222. By using the formulas for calculating series capacitance and the capacitance of the second capacitor, a capacitance-area relationship can be obtained that represents the relationship between the change in capacitance between the first plate 211 and any of the second plates 212, and the change in the effective area where the second plate 212 and the second floating plate 222 face each other. The capacitance of each capacitor composed of the second plate 212 and the first plate 211 can be associated with the respective capacitance-area relationship. From the facing areas of different second plates 212 and second floating plates 222, the relative positional relationship between the second floating plate 222 and the other second plate 212 can be calculated, and furthermore, 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] To those skilled in the art, the embodiments described above are merely specific examples for realizing the present application, and it is clear that in actual application, various formal and detailed modifications will not depart from the spirit and scope of the present application. Furthermore, since those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application, the scope of protection of the present application should be based on the scope limited by the claims.

Claims

1. It comprises a stator and a rotor, The first surface of the stator is provided with a first electrode plate and a plurality of second electrode plates arranged at intervals, the plurality of second electrode plates are arranged surrounding the first electrode plate, and the first electrode plate and the second electrode plates are connected to a detection circuit. The second surface of the rotor is provided with a first floating electrode plate and a second floating electrode plate connected to each other, the first floating electrode plate facing the first electrode plate to form a first capacitor, and the second floating electrode plate facing the second electrode plate to form a second capacitor. An angle detection device characterized by the following features.

2. The orthographic projection of the first floating electrode plate onto the first surface is located within the orthographic projection of the first electrode plate on the first surface. An angle detection device according to claim 1, characterized by the features described above.

3. The orthographic projection of the second electrode plate on the first surface is located within the orthographic projection of the second floating electrode plate on the first surface. An angle detection device according to claim 1, characterized by the features described above.

4. The number of the aforementioned two electrodes is three or more. An angle detection device according to claim 1, characterized by the features described above.

5. The number of the second electrode plates is N. In the direction along the circumferential direction of the first electrode plate, the length of the second floating electrode plate is longer than the length of one of the second electrode plates, and the length of the second floating electrode plate is shorter than the total length of N-1 of the second electrode plates. The angle detection device according to claim 4.

6. The first electrode plate is circular in shape, and the second electrode plate is fan-shaped. The first floating electrode plate has a circular shape, and the second floating electrode plate has a fan shape. An angle detection device according to claim 1, characterized by the features described above.

7. An earth wire is further provided on the first surface. The ground wire is connected to the detection circuit. The ground wire is arranged to surround the first electrode plate and is located between the first electrode plate and the second electrode plate. An angle detection device according to claim 1, characterized by the features described above.

8. The number of the second floating electrode plates may be two. The two second floating electrode plates are arranged symmetrically with respect to the center point of the first floating electrode plate. The number of the aforementioned second electrode plates is even. An angle detection device according to claim 1, characterized by the features described above.

9. An insulating layer is provided between the adjacent second electrode plates. An angle detection device according to claim 1, characterized by the features described above.

10. An angle detection method performed using an angle detection device according to any one of claims 1 to 9, The rotor is rotated 360° around the axis of rotation from its initial state relative to the stator, and a capacitance-area relationship and an area-angle relationship are obtained for each of the second electrodes, wherein the capacitance in the capacitance-area relationship is the capacitance between the first electrode and any of the second electrodes, the area in the capacitance-area relationship and the area-angle relationship is the effective area where any of the second electrodes and the second floating electrode face each other directly, and the angle in the area-angle relationship is the angle by which the rotor has rotated from its initial state. Using the capacity-area relationship and the area-angle relationship, a corresponding capacity-angle relationship is obtained for each of the second plates, where the capacity in the capacity-angle relationship is the capacity between the first plate and any of the second plates, and the angle in the capacity-angle relationship is the angle by which the rotor has rotated from the initial state. The real-time capacitance between the second electrode plate and the second floating electrode plate is obtained, By introducing the aforementioned real-time capacitance into the corresponding capacitance-angle relationship, the real-time rotation angle obtained is obtained as the rotor rotates around the rotation axis relative to the stator from the initial state. An angle detection method characterized by the above.

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