Motor rotation angle detection system and method

Abstract

The invention relates to the technical field of motors, and particularly discloses a motor rotation angle detection system and method, and the system comprises a separation blade which is provided with a spiral outer edge and linear edges connected with the two ends of the spiral outer edge; the first reflection type optocoupler is arranged on one side, deviating from the motor, of the separation blade; the controller is used for obtaining the first induction current based on the first reflection type optocoupler when the motor rotates and obtaining the rotation angle of the motor according to the first induction current and a preset conversion relation; according to the motor rotation angle detection system, a motor rotation shaft rotates to drive a separation blade to rotate synchronously, so that the coverage range of the separation blade in a first effective area is changed based on a spiral outer edge with a continuous change characteristic, and then a first reflection type optocoupler generates a first induction current with continuous change; the controller can calculate the rotation angle of the motor in real time according to the size of the first induction current, and has the advantages of being low in structural complexity and low in cost.

Description

Technical Field

[0001] The present application relates to the field of motor technology, and in particular, to a motor rotation angle detection system and method. Background Art

[0002] Motor rotation angle detection is a crucial link in the motor control system. Currently common detection solutions include absolute position photoelectric encoders, Hall sensors, and resolvers.

[0003] The absolute position photoelectric encoder uses multiple groups of photoelectric sensors and the encoder disk to accurately map the motor's rotation angle to binary information on the encoder disk. The number of code tracks on the encoder disk directly determines the accuracy of the angle division, but this also increases the number of photoelectric sensors required, thereby increasing the complexity and cost of the system.

[0004] The Hall sensor detects the position of the magnet on the motor shaft to calculate the rotation angle. However, this solution has problems such as poor output linearity and high cost.

[0005] The resolver needs to be used with a decoder to resolve the motor's rotational position. Although its performance is stable, the processing flow is relatively complex and the overall cost is high, which limits its widespread application.

[0006] These motor rotation angle detection solutions have disadvantages to varying degrees in terms of cost, system complexity, linearity, and processing flexibility.

[0007] There is currently no effective technical solution to the above problems. Summary of the invention

[0008] The purpose of the present application is to provide a motor rotation angle detection system and method to detect the rotation angle in order to overcome the shortcomings in cost, system complexity, linearity and processing flexibility.

[0009] In a first aspect, the present application provides a motor rotation angle detection system for detecting the rotation angle of a motor, the system comprising: A baffle, fixed on the rotating shaft of the motor, with its plate surface perpendicular to the axis of the rotating shaft, the baffle having a spiral outer edge and straight edges connecting two ends of the spiral outer edge; A first reflective optical coupler is arranged on a side of the baffle away from the motor, the minimum distance between the first effective area and the axis of the rotating shaft is less than the minimum distance between the outer edge of the spiral and the axis of the rotating shaft, the maximum distance between the first effective area and the axis of the rotating shaft is greater than the maximum distance between the outer edge of the spiral and the axis of the rotating shaft, and the first effective area is an effective reflective area generated by the first reflective optical coupler on the plane where the baffle is away from the motor; The controller is used to obtain a first induced current based on the first reflective optical coupler when the motor rotates, and to obtain a rotation angle of the motor according to the first induced current and a preset conversion relationship.

[0010] The motor rotation angle detection system of the present application drives the baffle to rotate synchronously by rotating the motor shaft, so as to change the coverage of the baffle in the first effective area based on the spiral outer edge with continuously changing characteristics, thereby causing the first reflective optocoupler to generate a continuously changing first induced current, so that the controller can calculate the rotation angle of the motor in real time according to the magnitude of the first induced current. It has the advantages of low structural complexity and low cost, and the spiral outer edge with continuously changing characteristics can ensure the linear relationship between the first induced current and the rotation angle of the motor, and can output the rotation angle of the motor in real time, accurately and flexibly.

[0011] The motor rotation angle detection system, wherein the straight line edge is radially perpendicular to the axis of the rotating shaft.

[0012] In this example, the straight edge is arranged to be radially perpendicular to the axis of the rotation axis to maximize the coverage of the spiral outer edge.

[0013] The motor rotation angle detection system, wherein the conversion relationship includes a fitting curve regarding the first induced current and the rotation angle.

[0014] The motor rotation angle detection system, wherein the first effective area is a rectangular area whose length direction is perpendicular to the axis of the rotating shaft.

[0015] In the motor rotation angle detection system, the first reflective optical coupler includes a first light-emitting device and a first photosensitive device arranged vertically, and the photosensitive surface of the first light-emitting device and the light-emitting surface of the first photosensitive device are both arranged toward the baffle.

[0016] The motor rotation angle detection system, wherein the baffle has an opening at a middle position between the center thereof and the straight edge; The system further comprises: A second reflective optical coupler is disposed on a side of the baffle away from the motor and located at a middle position between the first reflective optical coupler and the center of the baffle; The process of obtaining a first induced current based on the first reflective optical coupler when the motor rotates, and obtaining a rotation angle of the motor according to the first induced current and a preset conversion relationship includes: When the motor rotates, obtaining a first induced current based on the first reflective optocoupler and obtaining a second induced current based on the second reflective optocoupler; Selecting a preset conversion relationship based on the magnitude of the second induced current; The rotation angle of the motor is obtained according to the first induced current and a preset conversion relationship.

[0017] The motor rotation angle detection system, wherein the minimum distance between the second effective area and the axis line of the rotating shaft is smaller than the minimum distance between the opening and the axis line of the rotating shaft, the maximum distance between the second effective area and the axis line of the rotating shaft is larger than the maximum distance between the opening and the axis line of the rotating shaft, and the second effective area is the effective reflective area generated by the second reflective optical coupler on the plane where the baffle is away from the board surface of the motor.

[0018] The motor rotation angle detection system, wherein the rotation angle range of the motor during the process of the opening passing through the second effective area covers the rotation angle range of the motor during the process of the straight edge passing through the first effective area.

[0019] In the motor rotation angle detection system, the axis line of the rotating shaft coincides with the spiral axis of the spiral outer edge.

[0020] In a second aspect, the present application further provides a motor rotation angle detection method, which is applied in a motor rotation angle detection system, the system comprising: A baffle, fixed on the rotating shaft of the motor, with its plate surface perpendicular to the axis of the rotating shaft, the baffle having a spiral outer edge and straight edges connecting two ends of the spiral outer edge; A first reflective optical coupler is arranged on a side of the baffle away from the motor, the minimum distance between the first effective area and the axis of the rotating shaft is less than the minimum distance between the outer edge of the spiral and the axis of the rotating shaft, the maximum distance between the first effective area and the axis of the rotating shaft is greater than the maximum distance between the outer edge of the spiral and the axis of the rotating shaft, and the first effective area is an effective reflective area generated by the first reflective optical coupler on the plane where the baffle is away from the motor; The method comprises the steps of: When the motor rotates, obtaining a first induced current based on the first reflective optical coupler; The rotation angle of the motor is obtained according to the first induced current and a preset conversion relationship.

[0021] The motor rotation angle detection method of the present application drives the baffle to rotate synchronously by rotating the motor shaft, so as to change the coverage of the baffle in the first effective area based on the spiral outer edge with continuously changing characteristics, thereby causing the first reflective optocoupler to generate a continuously changing first induced current, so as to calculate the motor's rotation angle in real time according to the magnitude of the first induced current.

[0022] As can be seen from the above, the present application provides a motor rotation angle detection system and method, wherein the motor rotation angle detection system drives the baffle to rotate synchronously through the rotation of the motor shaft, so as to change the coverage of the baffle in the first effective area based on the spiral outer edge with a continuously changing characteristic, thereby causing the first reflective optocoupler to generate a continuously changing first induced current, so as to calculate the rotation angle of the motor in real time according to the magnitude of the first induced current. It has the advantages of low structural complexity and low cost, and the spiral outer edge with a continuously changing characteristic can ensure the linear relationship between the first induced current and the rotation angle of the motor, and can output the rotation angle of the motor in real time, accurately and flexibly. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of the structure of a motor rotation angle detection system provided in an embodiment of the present application.

[0024] Figure 2 It is a schematic diagram of the working principle of the existing reflective optocoupler.

[0025] Figure 3 Schematic diagram of the positional relationship between the baffle and the first reflective optical coupler.

[0026] Figure 4 for Figure 3 A partial enlarged view of .

[0027] Figure 5 Schematic diagram of the positional relationship between the baffle, the first reflective optical coupler, and the second reflective optical coupler.

[0028] Figure 6 This is a graph showing the changes of the first induced current and the second induced current with respect to the rotation angle.

[0029] Figure 7 A flowchart of a method for detecting a motor rotation angle provided in some embodiments of the present application.

[0030] Figure numerals: 1. motor; 2. baffle; 3. first reflective optocoupler; 4. controller; 5. first effective area; 6. second reflective optocoupler; 21. spiral outer edge; 22. straight edge; 23. opening; 31. first light-emitting device; 32. first photosensitive device. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0032] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0033] First, please refer to Figure 1 and Figure 3 Some embodiments of the present application provide a motor rotation angle detection system for detecting the rotation angle of a motor 1, the system comprising: The baffle 2 is fixed on the rotating shaft of the motor 1, and its plate surface is perpendicular to the axis of the rotating shaft. The baffle 2 has a spiral outer edge 21 and straight edges 22 connecting the two ends of the spiral outer edge 21; The first reflective optical coupler 3 is arranged on the side of the baffle 2 away from the motor 1, the minimum distance between the first effective area 5 and the axis of the rotating shaft is less than the minimum distance between the spiral outer edge 21 and the axis of the rotating shaft, the maximum distance between the first effective area 5 and the axis of the rotating shaft is greater than the maximum distance between the spiral outer edge 21 and the axis of the rotating shaft, and the first effective area 5 is an effective reflective area generated by the first reflective optical coupler 3 on the plane where the baffle 2 is away from the motor 1; The controller 4 is used to obtain a first induced current based on the first reflective optical coupler 3 when the motor 1 rotates, and to obtain a rotation angle of the motor 1 according to the first induced current and a preset conversion relationship.

[0034] Specifically, Figure 2As shown, the reflective optocoupler generally includes a photosensitive device and a light-emitting device, and its measurement principle is to detect the object based on the photosensitive device receiving the amount of light reflected by the light-emitting device projected on the detection object to generate an induced current, wherein the photosensitive device and the light-emitting device realize object detection based on the effective reflective area, and the effective reflective area is the theoretical maximum intersection of the illuminated surface formed by the light emitted by the light-emitting device on the surface of the detection object and the projection surface formed by the light-sensitive surface of the photosensitive device on the surface of the light-blocking plate (equivalent to the light-blocking plate 2). The detection object reflects light by covering part or all of the effective reflective area so that the reflective optocoupler generates an induced current based on the reflected light received by the photosensitive device, and the area of ​​the effective reflective area covered by the detection object is proportional to the induced current.

[0035] More specifically, in the embodiments of the present application, Figure 1 As shown, the shaft of the motor 1 is fixedly connected to the baffle 2 through the rear end, and the first reflective optical coupler 3 is arranged on the side of the baffle 2 away from the motor 1 to avoid affecting the front end rotation output; in order to accurately describe the conversion relationship between the induced current and the rotation angle of the motor 1, the spiral outer edge 21 appears as a spiral line with a continuously increasing radius on the corresponding plate surface of the baffle 2, that is, it has a radius that increases linearly, which can be described based on r=kθ+c, 0≤θ≤360°, where r is the radius of the spiral line, θ is the angle, and k and c are constants.

[0036] It should be noted that the first reflective optical coupler 3 can be fixed in the scene or other supporting equipment to maintain a fixed gap distance between it and the baffle 2, and its relative position with the housing of the motor 1 is fixed, so that when the motor 1 rotates, it can generate a corresponding first induced current based on the reflective effect of the baffle 2 to detect the rotation angle of the motor 1.

[0037] It should be noted that the controller 4 is electrically connected to the first reflective optical coupler 3 .

[0038] More specifically, if Figure 4 As shown, the setting range of the first effective area 5 can cover the minimum radius and the maximum radius of the spiral outer edge 21, so that when the motor 1 rotates, the baffle 2 is always in a state of partially covering the first effective area 5, so that the first induced current generated by the first reflective optical coupler 3 continues to change and the first induced current changes cyclically with respect to the rotation period of each rotating shaft. Combined with the preset conversion relationship that characterizes the first induced current and the rotation angle of the motor 1, the current rotation angle of the motor 1 can be calculated according to the first induced current.

[0039] The motor rotation angle detection system of the embodiment of the present application drives the baffle 2 to rotate synchronously by rotating the shaft of the motor 1, so as to change the coverage of the baffle 2 in the first effective area 5 based on the spiral outer edge 21 with a continuously changing characteristic, thereby causing the first reflective optical coupler 3 to generate a continuously changing first induced current, so that the controller 4 can calculate the rotation angle of the motor 1 in real time according to the magnitude of the first induced current. It has the advantages of low structural complexity and low cost, and the spiral outer edge 21 with a continuously changing characteristic can ensure the linear relationship between the first induced current and the rotation angle of the motor 1, and can output the rotation angle of the motor 1 in real time, accurately and flexibly.

[0040] In some preferred embodiments, the straight edge 22 is radially perpendicular to the axis of the rotating shaft.

[0041] Specifically, the straight edge 22 is arranged to be radially perpendicular to the axis of the rotation axis to maximize the coverage of the spiral outer edge 21. Figure 3 When the baffle 2 in the motor rotates counterclockwise, the relationship between the rotation angle of the motor 1 and the change of the first induced current is as follows: Figure 6 As shown, the decreasing line portion represents the change process of the first induced current when the straight edge 22 passes through the first effective area 5. The straight edge 22 is set to be radially perpendicular to the axis of the rotating shaft to reduce the range of the rotation angle of the motor 1 occupied by the change process and extend the range of the rotation angle of the motor 1 occupied by the increasing line.

[0042] In some preferred embodiments, the length of the straight edge 22 is 0.9-0.95 times the length of the first effective area 5 .

[0043] Specifically, the length of the straight edge 22 is related to the radius increase rate of the spiral line of the spiral outer edge 21 (that is, the aforementioned constant k). The greater the radius increase rate, the greater the length of the straight edge 22. Based on the relationship that "the minimum distance between the first effective area 5 and the axis centerline of the rotating shaft is less than the minimum distance between the spiral outer edge 21 and the axis centerline of the rotating shaft, and the maximum distance between the first effective area 5 and the axis centerline of the rotating shaft is greater than the maximum distance between the spiral outer edge 21 and the axis centerline of the rotating shaft", it can be known that the length of the straight edge 22 must be less than the length of the first effective area 5. The larger the straight edge 22 is set, the more conducive it is to generating a first induced current with a greater degree of change, that is, increasing Figure 6 The slope of the increasing line in the first effective area 5 is adjusted to make full use of the first effective area 5 so that the first reflective optical coupler 3 generates a first induced current with a larger difference during the rotation of the motor 1, so that the controller 4 can more accurately analyze and calculate the rotation angle of the motor 1.

[0044] In some preferred embodiments, the conversion relationship includes a fitting curve between the first induced current and the rotation angle.

[0045] Specifically, in order to improve the output accuracy of the rotation angle of the motor 1, the motor rotation angle detection system of the embodiment of the present application determines the conversion relationship by calculating the fitting curve, that is, by fitting the first induced current corresponding to multiple different rotation angles for multiple measurements to obtain the conversion relationship, such as Figure 6 As shown, the fitting curve includes two segments of alternating fitting straight lines, wherein the decreasing line corresponds to the changing relationship between the first induced current generated in the process from the straight line edge 22 entering the first effective area 5 to leaving the first effective area 5 and the rotation angle of the motor 1. The motor rotation angle detection system of the embodiment of the present application obtains the conversion relationship between the first induced current and the rotation angle in a rotation period (2π) by experimental measurement and curve fitting, which can ensure that the controller 4 can accurately and conveniently calculate the corresponding rotation angle of the motor 1 according to the first induced current, and can also accurately distinguish the two-segment changing characteristics of the first induced current.

[0046] More specifically, in other embodiments, in order to further improve the accuracy of the fitting curve, the conversion relationship can be divided into multiple fitting straight lines based on a preset angular spacing for fitting, such as dividing the rotation period (2π) into n (n is greater than 2) intervals, sampling each interval multiple times and performing straight line fitting to obtain fitting straight line segments, and finally combining these fitting straight line segments into a fitting curve.

[0047] In some implementations, the conversion relationship includes: (1) Among them, I 1 is the first induced current, I 10 is the first induced current when θ is 0, k and c are the constants of the spiral line of the spiral outer edge 21, a is the width of the first effective area 5, θ is the rotation angle of the motor 1, wherein, the definition Figure 3 The state shown corresponds to θ being 0 and λ being the conversion constant.

[0048] More specifically, the conversion constant λ is a design parameter of the first reflective optical coupler 3, which satisfies I 1 =λS, which can be obtained by measurement or by viewing the design instructions, wherein S is the effective reflective area, that is, the area of ​​the intersection of the area of ​​the detection object that blocks the emitted light and the first effective area 5.

[0049] More specifically, the motor rotation angle detection system of the embodiment of the present application can obtain the fitting curve by sampling fitting, or by obtaining the number of times I is divided by ... 1 The specific form of formula (1) can be determined by the unknown quantities other than θ to obtain the corresponding curve relationship. The two methods can also be combined for data verification to obtain the final conversion relationship. Among them, the sampling fitting method is actually equivalent to sampling multiple angles of I1 To calculate the process of determining λ.

[0050] In some preferred embodiments, the first effective area 5 is a rectangular area whose length direction is perpendicular to the axis of the rotation axis.

[0051] Specifically, the motor rotation angle detection system of the embodiment of the present application can more fully utilize the first effective area 5 to enable the first reflective optical coupler 3 to generate a first induced current with a larger difference during the rotation of the motor 1 by setting the first effective area 5 to be a rectangular area whose length direction is perpendicular to the axis of the rotating shaft, while also ensuring that the aforementioned conversion relationship contains two clear fitting straight lines in one rotation cycle.

[0052] In some preferred embodiments, the first reflective optical coupler 3 includes a first light emitting device 31 and a first photosensitive device 32 which are arranged vertically, and the photosensitive surface of the first light emitting device 31 and the light emitting surface of the first photosensitive device 32 are both arranged toward the baffle 2 .

[0053] Specifically, in the embodiment of the present application, the photosensitive surface of the first light-emitting device 31 and the light-emitting surface of the first photosensitive device 32 are both parallel to the outer panel surface of the baffle 2. The size of the first effective area 5 can be adjusted by changing the distance between the first light-emitting device 31 and the first photosensitive device 32 and changing the distance between the first light-emitting device 31 and the first photosensitive device 32 and the baffle 2. Therefore, the motor rotation angle detection system of the embodiment of the present application can conveniently adjust the size of the first effective area 5 according to usage requirements, so that the first effective area 5 meets the detection requirements of the rotation angle of the motor 1.

[0054] In some preferred embodiments, Figure 5 As shown, the baffle 2 has an opening 23 at a middle position between its center and the straight edge 22; The system also includes: The second reflective optical coupler 6 is arranged on a side of the baffle 2 away from the motor 1 and is located in the middle between the first reflective optical coupler 3 and the center of the baffle 2; The process of obtaining the first induced current based on the first reflective optical coupler 3 when the motor 1 rotates, and obtaining the rotation angle of the motor 1 according to the first induced current and a preset conversion relationship includes: When the motor 1 rotates, a first induced current is obtained based on the first reflective optical coupler 3 and a second induced current is obtained based on the second reflective optical coupler 6; Selecting a preset conversion relationship based on the magnitude of the second induced current; The rotation angle of the motor 1 is acquired according to the first induced current and a preset conversion relationship.

[0055] Specifically, based on the foregoing content, it can be known that the conversion relationship includes two parts, namely, an increasing line and a decreasing line, that is, in the conversion relationship, each value of the first induced current actually corresponds to two rotation angles. In actual processing, the controller 4 can determine which of the two rotation angles the first induced current actually corresponds to based on the changing trend or periodic timing of the first induced current. However, in order to further simplify the complexity of the algorithm, the motor rotation angle detection system of the embodiment of the present application further introduces a second reflective optocoupler 6 as a distinction between an increasing line and a decreasing line.

[0056] More specifically, in the embodiment of introducing the second reflective optical coupler 6, the variation relationship of the second induced current generated by the second reflective optical coupler 6 and the first induced current generated by the first reflective optical coupler 3 with respect to the rotation period is as follows: Figure 6 As shown, when the opening 23 does not pass through the second effective area, the baffle 2 completely covers the second effective area, so that the second induced current generated by the second reflective optocoupler 6 always maintains the maximum value; and when the first induced current is located in the decreasing line part, the opening 23 just passes through the second effective area, so that the second induced current generated by the second reflective optocoupler 6 is lower than the maximum value. Therefore, the controller 4 can determine whether the current first induced current is located on the decreasing line part by judging whether the second induced current is lower than the maximum value (or comparing the size based on a preset threshold), and then call the appropriate fitting straight line segment in the conversion relationship to calculate the rotation angle of the motor 1; the motor rotation angle detection system of the embodiment of the present application introduces the second reflective optocoupler 6 to use the second induced current detected by it as a matching reference for the first induced current and the conversion relationship, so as to improve the accuracy of the rotation angle of the motor 1 while reducing the complexity of the algorithm.

[0057] More specifically, the operating principle and composition of the second reflective optical coupler 6 are consistent with those of the first reflective optical coupler 3 , and its structural composition and setting method are not described in detail here.

[0058] In some preferred embodiments, the process of selecting a preset conversion relationship based on the magnitude of the second induced current includes: The magnitude relationship between the second induced current and the current threshold is compared to select a preset conversion relationship, wherein the current threshold is the second induced current corresponding to the maximum value or the minimum value of the first induced current.

[0059] Specifically, based on Figure 6It can be seen that when the second induced current is lower than the maximum value, the front part and the rear part of the second induced current still have the problem that the first induced current value corresponds to two rotation angles. Therefore, the motor rotation angle detection system of the embodiment of the present application further sets the current threshold to divide the fitting straight line used in the conversion relationship. In actual operation, the value of the second induced current at the corresponding moment when the first induced current reaches the maximum value or the minimum value can be measured as the current threshold, so that when the second induced current is greater than or equal to the current threshold, the controller 4 selects the fitting straight line corresponding to the increasing line in the conversion relationship to calculate and obtain the rotation angle of the motor 1. When the second induced current is less than the current threshold, the controller 4 selects the fitting straight line corresponding to the decreasing line in the conversion relationship to calculate and obtain the rotation angle of the motor 1.

[0060] In some preferred embodiments, the minimum distance between the second effective area and the axis of the rotating shaft is less than the minimum distance between the opening 23 and the axis of the rotating shaft, the maximum distance between the second effective area and the axis of the rotating shaft is greater than the maximum distance between the opening 23 and the axis of the rotating shaft, and the second effective area is the effective reflective area generated by the second reflective optical coupler 6 on the plane where the baffle 2 is facing away from the motor 1.

[0061] More specifically, the above-mentioned setting method can ensure that when the opening 23 passes through the second effective area, the second induced current undergoes a linear decrease and linear increase process, ensuring that the controller 4 can accurately capture the change of the second induced current and select a suitable conversion relationship to calculate and obtain the rotation angle of the motor 1.

[0062] In some preferred embodiments, the rotation angle range of the motor 1 during the process in which the opening 23 passes through the second effective area covers the rotation angle range of the motor 1 during the process in which the straight edge 22 passes through the first effective area 5 .

[0063] Specifically, the above-mentioned setting method can ensure that the range of the rotation angle of the motor 1 corresponding to the continuous process in which the second induced current generated by the second reflective optocoupler 6 is lower than the maximum value includes the range of the rotation angle of the motor 1 corresponding to the process in which the first induced current is on the decreasing line.

[0064] In some preferred embodiments, the axis of the rotating shaft coincides with the spiral axis of the spiral outer edge 21 , which can ensure that there are multiple fitting linear relationships between the first induced current and the rotation angle of the motor 1 in one rotation cycle.

[0065] Second, please refer to Figure 7 Some embodiments of the present application also provide a motor rotation angle detection method, which is applied in a motor rotation angle detection system, and the system includes: The baffle 2 is fixed on the rotating shaft of the motor 1, and its plate surface is perpendicular to the axis of the rotating shaft. The baffle 2 has a spiral outer edge 21 and straight edges 22 connecting the two ends of the spiral outer edge 21; The first reflective optical coupler 3 is arranged on the side of the baffle 2 away from the motor 1, the minimum distance between the first effective area 5 and the axis of the rotating shaft is less than the minimum distance between the spiral outer edge 21 and the axis of the rotating shaft, the maximum distance between the first effective area 5 and the axis of the rotating shaft is greater than the maximum distance between the spiral outer edge 21 and the axis of the rotating shaft, and the first effective area 5 is an effective reflective area generated by the first reflective optical coupler 3 on the plane where the baffle 2 is away from the motor 1; The method comprises the steps of: S1, obtaining a first induced current based on a first reflective optical coupler 3 when the motor 1 rotates; S2. Obtain the rotation angle of the motor 1 according to the first induced current and a preset conversion relationship.

[0066] The motor rotation angle detection method of the embodiment of the present application drives the baffle 2 to rotate synchronously by rotating the shaft of the motor 1, so as to change the coverage of the baffle 2 in the first effective area 5 based on the spiral outer edge 21 with a continuously changing characteristic, thereby causing the first reflective optical coupler 3 to generate a continuously changing first induced current, so as to calculate the rotation angle of the motor 1 in real time according to the magnitude of the first induced current. The method has the advantages of low structural complexity and low cost, and the spiral outer edge 21 with a continuously changing characteristic can ensure the linear relationship between the first induced current and the rotation angle of the motor 1, and can output the rotation angle of the motor 1 in real time, accurately and flexibly.

[0067] In addition, the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0068] Furthermore, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0069] In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0070] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A motor rotation angle detection system, used to detect the rotation angle of a motor, characterized in that: The system comprises: A baffle, fixed on the rotating shaft of the motor, with its plate surface perpendicular to the axis of the rotating shaft, the baffle having a spiral outer edge and straight edges connecting two ends of the spiral outer edge; A first reflective optical coupler is arranged on a side of the baffle away from the motor, the minimum distance between the first effective area and the axis of the rotating shaft is less than the minimum distance between the outer edge of the spiral and the axis of the rotating shaft, the maximum distance between the first effective area and the axis of the rotating shaft is greater than the maximum distance between the outer edge of the spiral and the axis of the rotating shaft, and the first effective area is an effective reflective area generated by the first reflective optical coupler on the plane where the baffle is away from the motor; The controller is used to obtain a first induced current based on the first reflective optical coupler when the motor rotates, and to obtain a rotation angle of the motor according to the first induced current and a preset conversion relationship.

2. The motor rotation angle detection system according to claim 1, characterized in that: The straight edge is radially perpendicular to the axis of the rotating shaft.

3. The motor rotation angle detection system according to claim 1, characterized in that: The conversion relationship includes a fitting curve regarding the first induced current and the rotation angle.

4. The motor rotation angle detection system according to claim 1, characterized in that: The first effective area is a rectangular area whose length direction is perpendicular to the axis of the rotating shaft.

5. The motor rotation angle detection system according to claim 1, characterized in that: The first reflective optical coupler includes a first light emitting device and a first photosensitive device which are arranged one above the other. The photosensitive surface of the first light emitting device and the light emitting surface of the first photosensitive device are both arranged toward the baffle.

6. The motor rotation angle detection system according to claim 1, characterized in that: The baffle has an opening at a middle position between the center and the straight edge; The system further comprises: A second reflective optical coupler is disposed on a side of the baffle away from the motor and located at a middle position between the first reflective optical coupler and the center of the baffle; The process of obtaining a first induced current based on the first reflective optical coupler when the motor rotates, and obtaining a rotation angle of the motor according to the first induced current and a preset conversion relationship includes: When the motor rotates, obtaining a first induced current based on the first reflective optocoupler and obtaining a second induced current based on the second reflective optocoupler; Selecting a preset conversion relationship based on the magnitude of the second induced current; The rotation angle of the motor is obtained according to the first induced current and a preset conversion relationship.

7. The motor rotation angle detection system according to claim 6, characterized in that: The minimum distance between the second effective area and the axis of the rotating shaft is smaller than the minimum distance between the opening and the axis of the rotating shaft, the maximum distance between the second effective area and the axis of the rotating shaft is larger than the maximum distance between the opening and the axis of the rotating shaft, and the second effective area is the effective reflective area generated by the second reflective optical coupler on the plane where the baffle is away from the board surface of the motor.

8. The motor rotation angle detection system according to claim 6, characterized in that: The rotation angle range of the motor during the process of the opening passing through the second effective area covers the rotation angle range of the motor during the process of the straight edge passing through the first effective area, and the second effective area is the effective reflective area generated by the second reflective optical coupler on the plane where the baffle is away from the board surface of the motor.

9. The motor rotation angle detection system according to claim 1, characterized in that: The axis center line of the rotating shaft coincides with the spiral axis center of the spiral outer edge.

10. A motor rotation angle detection method, applied in a motor rotation angle detection system, characterized in that: The system comprises: A baffle, fixed on the rotating shaft of the motor, with its plate surface perpendicular to the axis of the rotating shaft, the baffle having a spiral outer edge and straight edges connecting two ends of the spiral outer edge; A first reflective optical coupler is arranged on a side of the baffle away from the motor, the minimum distance between the first effective area and the axis of the rotating shaft is less than the minimum distance between the outer edge of the spiral and the axis of the rotating shaft, the maximum distance between the first effective area and the axis of the rotating shaft is greater than the maximum distance between the outer edge of the spiral and the axis of the rotating shaft, and the first effective area is an effective reflective area generated by the first reflective optical coupler on the plane where the baffle is away from the motor; The method comprises the steps of: When the motor rotates, obtaining a first induced current based on the first reflective optical coupler; The rotation angle of the motor is obtained according to the first induced current and a preset conversion relationship.

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