Rotation angle calculation device, rotation angle calculation system, rotation angle calculation method, and rotation angle calculation program

Abstract

A rotation angle calculation device is provided with: an acquisition unit (21) for acquiring, from each of three detection elements (11) disposed at a position offset by a 120-degree electrical angle with respect to one permanent magnet (4) included in a detection target for detecting a rotation angle, a detection result for detecting a leakage magnetic flux generated from the permanent magnet (4); a generation unit (22) that generates an orthogonal component signal indicating two orthogonal components of the intensity of the leakage magnetic flux by using the three acquired detection results; and a calculation unit (23) that calculates the rotation angle of the object to be detected using the orthogonal component signal.

Description

Citation of related applications

[0001] This application claims priority based on Japanese patent application No. 2022-162725 filed on October 7, 2022, and the entire contents of the patent application are incorporated into this specification by reference. Technical Field

[0002] The present disclosure relates to a rotation angle calculation device, a rotation angle calculation system, a rotation angle calculation method, and a rotation angle calculation program for calculating a rotation angle of a detection object. Background Art

[0003] Patent Document 1 discloses a permanent magnet synchronous motor device, in which two Hall sensors for detecting magnetic flux generated by a permanent magnet are arranged at a position where the rotation electrical angle is greater than 0 degrees and less than 180 degrees relative to a rotor provided with a permanent magnet. The permanent magnet synchronous motor device generates a current for exciting a winding of a driving rotor based on a signal detected by the Hall sensor.

[0004] The permanent magnet synchronous motor device includes a controller that controls the current for exciting the windings that drives the rotor. The controller controls the current for exciting the windings based on a signal detected by the Hall element, and thus torque ripple can be suppressed. Prior art literature Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2005-323490 Summary of the invention

[0006] In addition, it is desirable that the waveform of the signal representing the magnetic flux intensity detected by the two Hall elements is a first-order sine wave relative to the electrical angle, and the more it deviates from the first-order sine wave, the more errors will be generated in the calculated rotation angle. In other words, when the signals detected by the two Hall elements are used to generate signals of two orthogonal components relative to the electrical angle, the signals contain noise, and an error may sometimes occur between the calculated result and the current rotation angle for the rotation angle of the detection object.

[0007] The purpose of the present disclosure is to provide a rotation angle calculation device, a rotation angle calculation system, a rotation angle calculation method and a rotation angle calculation program, which can suppress the error between the calculation result and the current rotation angle of the detection object when generating signals of two orthogonal components relative to the electrical angle.

[0008] The first mode of the rotation angle calculation device disclosed in the present invention includes: an acquisition unit, which acquires detection results of leakage magnetic flux generated from a permanent magnet included in a detection object for detecting the rotation angle from three detection elements respectively arranged at positions deviated by 120 electrical angles relative to the above-mentioned permanent magnet; a generation unit, which uses the three acquired detection results to generate orthogonal component signals of two orthogonal components representing the intensity of the above-mentioned leakage magnetic flux; and a calculation unit, which uses the above-mentioned orthogonal component signals to calculate the rotation angle of the above-mentioned detection object.

[0009] In addition, the rotation angle calculation method of the second mode of the present invention enables the computer to perform the following processing: obtain detection results of leakage magnetic flux generated from a permanent magnet included in the motor as the object of detecting the rotation angle from three detection elements respectively arranged at positions deviated by 120 electrical angles relative to the above-mentioned permanent magnet, use the three above-mentioned detection results obtained, generate orthogonal component signals of two orthogonal components representing the intensity of the above-mentioned leakage magnetic flux, and use the above-mentioned orthogonal component signals to calculate the rotation angle of the above-mentioned motor.

[0010] In addition, the third-party rotation angle calculation program of the present invention enables at least one processor to perform the following processing: obtaining detection results of leakage magnetic flux generated from a permanent magnet included in an electric motor as an object for detecting the rotation angle from three detection elements respectively arranged at positions deviated by 120 electrical degrees relative to the above-mentioned permanent magnet, using the three above-mentioned detection results obtained, generating orthogonal component signals of two orthogonal components representing the intensity of the above-mentioned leakage magnetic flux, and using the above-mentioned orthogonal component signals to calculate the rotation angle of the above-mentioned motor. Effects of the Invention

[0011] According to the present disclosure, when signals of two orthogonal components with respect to the electrical angle are generated, it is possible to suppress an error between a calculation result and the current rotation angle of the detection object. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The above objects, other objects, features and advantages of the present disclosure will become more apparent with reference to the accompanying drawings and the following detailed description. Figure 1 It is a schematic diagram showing an example of the configuration of the rotation angle calculation system according to the present embodiment. Figure 2 This is a block diagram showing an example of the hardware configuration of the rotation angle calculation device according to the present embodiment. Figure 3 This is a block diagram showing an example of the functional configuration of the rotation angle calculation device according to the present embodiment. Figure 4 This is a graph showing an example of the detection result of the electrical angle according to the present embodiment. Figure 5 It is a schematic diagram showing an example of the synthesized detection results of this embodiment. Figure 6 This is a graph showing an example of the synthesized detection result for the electrical angle according to the present embodiment. Figure 7 This is a flowchart showing an example of a process of calculating a rotation angle according to the present embodiment. Figure 8 It is a front view showing an example of the structure of the permanent magnet synchronous motor (SPM) according to the present embodiment. Fig. 9 It is a plan view showing an example of the structure of a permanent magnet synchronous motor for explaining the arrangement of the Hall elements according to the present embodiment. Fig.10 This is a front view showing an example of the structure of an embedded permanent magnet synchronous motor (IPM) according to Modification 1. Fig.11 This is a front view showing an example of the structure of an outer rotor type permanent magnet synchronous motor according to Modification 2. Fig.12 This is a front view showing an example of the structure of an axial gap permanent magnet synchronous motor according to Modification 3. DETAILED DESCRIPTION

[0013] Hereinafter, embodiments for implementing the present disclosure will be described in detail with reference to the drawings. Figure 1 It is a schematic diagram showing an example of the configuration of the rotation angle calculation system according to the present embodiment.

[0014] (Structure of rotation angle calculation system) As an example, Figure 1 As shown, the rotation angle calculation system 1 includes a permanent magnet synchronous motor 2 and a rotation angle calculation device 10 for calculating the rotation angle of the motor.

[0015] The electric motor 2 includes a rotor 5 and a stator 6 . The rotor 5 includes a rotor core 3 and permanent magnets 4 .

[0016] For example, the motor 2 is an inner rotor type permanent magnet synchronous motor in which the rotor 5 is arranged on the radial inner side of the stator 6. The permanent magnet 4 is fixed to the rotor core 3 and arranged in a manner that the direction of the magnetic field is alternately reversed between adjacent permanent magnets 4. The stator 6 includes pole teeth 6A for windings not shown in the figure and slots 6B formed between the pole teeth 6A. The stator core of the stator 6 is wound with windings not shown in the figure in a manner that spans the slots 6B. In addition, in the present embodiment, a method of a permanent magnet synchronous motor of a stator 6 having 8 poles and slots 6B (windings) having 12 slots is described. However, it is not limited to this. The permanent magnet 4 can also be 4-pole, the slots 6B (windings) can also be 8 slots, and the number of permanent magnets 4 and slots 6B can also be any number.

[0017] The rotation angle calculation device 10 includes a Hall element 11A, a Hall element 11B, and a Hall element 11C. In the following, when the Hall elements 11 are distinguished, they are described as the Hall element 11A, the Hall element 11B, and the Hall element 11C, and when they are not distinguished, they are described as the Hall element 11. In addition, the Hall element 11 is an example of a "detection element".

[0018] Each Hall element 11 is arranged inside the motor 2 at a position capable of detecting the leakage magnetic flux generated from the permanent magnet 4, and three Hall elements 11 are arranged relative to the permanent magnet 4 of one pole. As a result of the detection, the Hall element 11 outputs a signal indicating the intensity of the leakage magnetic flux. Here, each Hall element 11 is arranged at a position deviated by 120 degrees of electrical angle. In the case where the motor 2 includes a plurality of permanent magnets 4, the spacing at which each Hall element 11 is arranged is based on one Hall element 11 and is expressed by the following mathematical formula.

[0019] [Mathematical formula 1]

[0020] Here, d is the arrangement pitch of other Hall elements 11 relative to one Hall element 11 serving as a reference, and p is the number of pairs of magnetic poles (pole pairs) of the permanent magnet 4 included in the motor 2. s is an identifier for identifying each Hall element relative to a permanent magnet 4 of 1 pole, and can take any one of s=1 and 2. n is an identifier for identifying each permanent magnet, and can take any one of 0 to p-1.

[0021] For example, when the motor 2 has an 8-pole permanent magnet 4, the Hall elements 11 are arranged at intervals of 15 degrees at a mechanical angle along the circumferential direction of the motor 2. In addition, in order to avoid complexity, the following describes how the three Hall elements 11, namely, the Hall element 11A, the Hall element 11B, and the Hall element 11C, detect signals.

[0022] The rotation angle calculation device 10 uses the three-phase signals detected by the Hall element 11A, the Hall element 11B, and the Hall element 11C to derive their respective differences and generate a SIN signal and a COS signal. The rotation angle calculation device 10 uses the generated SIN signal and COS signal to calculate the rotation angle of the motor. In addition, the SIN signal and the COS signal are examples of "orthogonal component signals".

[0023] (Structure of rotation angle calculation device) Next, refer to Figure 2 , the hardware structure of the rotation angle calculation device 10 is described. Figure 2 This is a block diagram showing an example of the hardware configuration of the rotation angle calculation device according to the present embodiment.

[0024] As an example, Figure 2 As shown, the rotation angle calculation device 10 includes a Hall element 11, a control unit 12, a ROM (Read Only Memory) 13, a RAM (Random Access Memory) 14, an input / output interface (hereinafter referred to as "input / output I / F") 15, and an analog / digital conversion circuit (hereinafter referred to as "AD conversion circuit") 16. The control unit 12, the ROM 13, the RAM 14, and the A / D conversion circuit 16 are connected to each other through a bus 19.

[0025] The Hall element 11 is a sensor for detecting the leakage magnetic flux of the permanent magnet 4. The control unit 12 controls the entire rotation angle calculation device 10. The ROM 13 stores various programs and data. The RAM 14 is a memory used as a work area when executing various programs. The control unit 12 calculates the rotation angle of the detection object by developing and executing the program stored in the ROM 13 in the RAM 14.

[0026] The input / output I / F 15 is connected to the Hall element 11 and the AD conversion circuit 16 . The input / output I / F 15 outputs the three-phase signals input from the Hall element 11A, the Hall element 11B, and the Hall element 11C to the AD conversion circuit 16 .

[0027] The AD conversion circuit 16 converts the three-phase analog signal output from the input / output I / F 15 into a digital signal, and outputs the digital signal to the control unit 12 .

[0028] Next, refer to Figure 3 , the functional structure of the rotation angle calculation device 10 is described. Figure 3 This is a block diagram showing an example of the functional configuration of the rotation angle calculation device 10 according to the present embodiment.

[0029] As an example, Figure 3As shown, the rotation angle calculation device 10 includes an acquisition unit 21 , a generation unit 22 , and a calculation unit 23 .

[0030] The acquisition unit 21 acquires the digital signal obtained by converting the three-phase analog signal output by the Hall element 11 through the input / output I / F 15 and the AD conversion circuit 16. Figure 4 As shown, the Hall element 11 outputs three-phase analog signals of the U phase, the V phase, and the W phase. Here, the respective analog signals have a phase difference of 120 degrees from each other.

[0031] The generator 22 generates a mutually orthogonal SIN signal and COS signal using the three-phase digital signal acquired by the acquirer 21. Specifically, the generator 22 derives the difference between the values ​​of two signals in the three-phase signal, and generates the SIN signal and COS signal using the derived difference. The difference between the signals is expressed by the following mathematical formula.

[0032] [Mathematical formula 2] U′=UV...(2)

[0033] [Mathematical formula 3] V′=VW...(3)

[0034] [Formula 4] W′=WU...(4)

[0035] [Formula 5] V″=V′-W′...(5)

[0036] Here, U′ is the difference between the U-phase signal and the V-phase signal, V′ is the difference between the V-phase signal and the W-phase signal, W′ is the difference between the W-phase signal and the U-phase signal, and V″ is the difference between the V′-phase signal and the W′-phase signal.

[0037] When V″ is represented by using the U phase, V phase, and W phase, the above formula (5) is represented by the following mathematical formula.

[0038] [Mathematical formula 6] V ″ =U+V-2W...(6)

[0039] As an example, Figure 5 As shown, the U' phase represented by the above equation (2) and the V" phase represented by the above equation (6) are orthogonal to each other. The generating unit 22 normalizes the signal of the U' phase and generates a SIN signal, and normalizes the digital signal of the V" phase and generates a COS signal, thereby generating a signal of an orthogonal component. Figure 6 : is a graph showing an example of a SIN signal related to the U' phase and a COS signal related to the V" phase among the simulation signals according to the present embodiment.

[0040] The calculation unit 23 calculates the rotation angle of the detection object using the generated SIN signal and COS signal. Specifically, the calculation unit 23 calculates θ=tan -1 (SINθ / COSθ) is used to calculate the rotation angle of the detection object. Here, θ is the rotation angle of the detection object after rotation, and tan -1 is the inverse function of the tangent. SINθ is the value of the generated SIN signal, and COSθ is the value of the generated COS signal.

[0041] Next, refer to Figure 7 , a method for detecting a rotation angle according to this embodiment is described. Figure 7 This is a flowchart showing an example of a method for detecting a rotation angle according to the present embodiment.

[0042] In step S101 , the rotation angle calculation device 10 acquires a three-phase digital signal detected by the Hall element 11 and converted by the AD conversion circuit 16 .

[0043] In step S102 , the rotation angle calculation device 10 derives the respective difference values ​​using the acquired three-phase digital signals, and derives the values ​​of the U′ phase, the V′ phase, and the W′ phase.

[0044] In step S103 , the rotation angle calculation device 10 uses the values ​​of the V′ phase and the W′ phase and derives the V″ phase.

[0045] In step S104 , the rotation angle calculation device 10 normalizes the value of the U′-phase digital signal to generate a SIN signal, and normalizes the value of the V″-phase digital signal to generate a COS signal.

[0046] In step S105 , the rotation angle calculation device 10 calculates the rotation angle of the detection object using the generated SIN signal and COS signal.

[0047] (Configuration of Hall Element 11) Next, refer to Figure 8 , the arrangement of the Hall element 11 inside the motor 2 according to the present embodiment will be described. Figure 8 Schematic diagram showing an example of the structure of the motor 2 of the present embodiment. In addition, the motor 2 of the present embodiment is an inner rotor type permanent magnet synchronous motor in which the rotor 5 is provided radially inside the stator 6 .

[0048] As an example, Figure 8As shown, in the motor 2 of the present embodiment, the rotor 5 includes a rotor core 3 at the axial center and a permanent magnet 4 located radially outside the rotor core 3. The stator 6 includes a pole tooth 6A provided radially outside the rotor core 3 and a winding (coil) 7 wound around the pole tooth 6A. That is, in the motor 2 of the present embodiment, the rotor core 3, the permanent magnet 4 and the stator 6 are provided in order from the center of the motor 2 toward the radial direction.

[0049] The position of the Hall element 11 is configured at a position capable of detecting the leakage magnetic flux generated from the permanent magnet 4. Specifically, when the width (radial length) of the permanent magnet 4 is set to B, the radial position of the Hall element 11 is configured in the range from a position away from 3B at the radial inner end of the permanent magnet 4 (refer to arrow 31) to a position away from 3B at the radial outer end of the permanent magnet 4 (refer to arrow 32), thereby enabling the detection of leakage magnetic flux. In addition, the position of the Hall element 11 in the axial direction is also configured in the range from the axial upper end of the permanent magnet 4 to a position away from the end 3B (refer to arrow 33). In addition, it is desired that the position of the Hall element 11 in the axial direction does not exceed the height (axial length) of the winding 7.

[0050] In addition, in this embodiment, the arrangement of the Hall element 11 for detecting the leakage magnetic flux of the permanent magnet 4 is described. However, the present invention is not limited to this. The height of the permanent magnet 4 may be changed.

[0051] For example, the height (length in the axial direction) M of the permanent magnet 4 is expressed by the following mathematical formula.

[0052] [Formula 7] S+2A≤M≤1.3S...(7)

[0053] Here, S is the height (length in the axial direction) of the stator 6 (pole teeth 6A), and A is the size of the gap (air gap) between the rotor 5 and the stator 6 in the radial direction.

[0054] As shown in the above formula (7), it is desired that the height M of the permanent magnet 4 is within a range where the value obtained by adding the height of twice the size of the air gap A to the height S of the stator 6 (pole teeth 6A) is the lower limit and the value obtained by multiplying the height S of the stator 6 (pole teeth 6A) by 1.3 times is the upper limit. By setting the height of the permanent magnet 4 to the above formula (7), the configuration of the Hall element 11 becomes higher together with the height of the permanent magnet 4. Therefore, the distance between the Hall element 11 and the pole teeth 6A (winding 7) becomes larger, the distortion of the magnetic flux caused by the pole teeth 6A (winding 7) becomes smaller, and the detection accuracy of the leakage magnetic flux of the Hall element 11 is improved.

[0055] The Hall element 11 is disposed between adjacent pole teeth 6A (on the slots 6B) constituting the stator 6. In other words, the Hall element 11 is disposed between the windings (coils) 7 to reduce distortion of magnetic flux caused by the windings (coils) 7. Fig. 9 FIG. 1 is a top view showing an example of the structure of a permanent magnet synchronous motor for explaining the arrangement of the Hall element of the present embodiment. Fig. 9 As shown, the Hall element 11 is preferably disposed between one pole tooth 6A and another adjacent pole tooth 6A in the circumferential direction. The Hall element 11 can be provided between adjacent pole teeth 6A to suppress the influence of the magnetic flux generated by the winding (coil) 7.

[0056] (Variation 1 Regarding Arrangement of Hall Element 11) The motor 2 of the above embodiment is described as an SPM (Surface Permament Magnet) motor in which permanent magnets 4 are arranged around the rotor core 3. The motor 2 of this modification example 1 is described as an IPM (Interior Permament Magnet) motor in which permanent magnets 4 are buried in the rotor core 3.

[0057] Fig.10 is a schematic diagram showing an example of the structure of the motor 2 in the modification example 1. As an example, Fig.10 As shown, the rotor 5 of the motor 2 of Modification 1 includes the rotor core 3 at the axial center and the permanent magnet 4 located inside the rotor core 3. The stator 6 includes pole teeth 6A provided radially outside the rotor core 3 and windings (coils) 7 wound around the pole teeth 6A.

[0058] The configuration of the Hall element 11 in the variant 1 is similar to that in the above-mentioned embodiment, and is radially configured within the range from a position away from 3B at the radial inner end of the permanent magnet 4 (see arrow 34) to a position away from 3B at the radial outer end of the permanent magnet 4 (see arrow 35) relative to the width (radial length) B of the permanent magnet. In addition, the position of the Hall element 11 in the axial direction is also similarly configured within the range from the axial upper end of the permanent magnet 4 to a position away from the end 3B (see arrow 36). In addition, it is desired that the position of the Hall element 11 in the axial direction does not exceed the height (axial length) of the winding 7.

[0059] As shown in the above formula (7), for the height of the permanent magnet 4 in variant example 1, when the size of the gap (air gap) between the rotor 5 and the stator 6 is set to A, it is expected that the height M of the permanent magnet 4 is within a range where the lower limit is the value obtained by adding the height of twice the size of the air gap A to the height S of the stator 6 (pole tooth 6A) and the upper limit is the value obtained by multiplying the height S of the stator 6 (pole tooth 6A) by 1.3 times.

[0060] (Variation Example 2 Regarding Arrangement of Hall Element 11) The motor 2 of the above embodiment is an inner rotor type permanent magnet synchronous motor in which the rotor 5 is provided radially inside the stator 6. The motor 2 of this modification is an outer rotor type permanent magnet synchronous motor in which the rotor 5 is provided radially outside the stator 6.

[0061] Fig.11 is a schematic diagram showing an example of the structure of the motor 2 in the modification 2. As an example, Fig.11 As shown, the rotor 5 of the motor 2 of the modification 2 includes a rotor core 3 and a permanent magnet 4 arranged radially inside the rotor core 3. The stator 6 is composed of a pole tooth 6A arranged radially inside the rotor core 3 and a winding (coil) 7 wound around the pole tooth 6A. That is, in the motor 2 of the present embodiment, the stator 6, the permanent magnet 4 and the rotor core 3 are arranged in order from the center of the motor 2 toward the radial direction.

[0062] The configuration of the Hall element 11 in variant example 2 is the same as that in the above-mentioned embodiment, and is radially configured within a range from a position away from 3B at the radial inner end of the permanent magnet 4 (see arrow 37) to a position away from 3B at the radial outer end (see arrow 38) relative to the width (radial length) B of the permanent magnet.

[0063] (Variation 3 Regarding Arrangement of Hall Element 11) The motor 2 of the above embodiment is described as a radial gap type permanent magnet synchronous motor in which the permanent magnet 4 is arranged in a manner that the direction of the magnetic field is radial. The motor 2 of this modified example is described as an axial gap type permanent magnet synchronous motor in which the permanent magnet 4 is arranged in a manner that the direction of the magnetic field is axial.

[0064] Fig.12 is a schematic diagram showing an example of the structure of the motor 2 in the modification example 3. As an example, Fig.12 As shown, the rotor 5 of the motor 2 of Modification 3 includes a rotor core 3 of a driving part and a permanent magnet 4 located axially above the rotor core 3. The stator 6 includes pole teeth 6A provided axially above the rotor core 3 and windings (coils) 7 wound around the pole teeth 6A.

[0065] The configuration of the Hall element 11 in the variant example 3 is similar to that in the above-mentioned embodiment, and is axially configured within the range from a position away from 3B at the axial upper end of the permanent magnet 4 (see arrow 39) to a position away from 3B at the axial lower end of the permanent magnet 4 (see arrow 40) relative to the height (axial length) B of the permanent magnet 4. In addition, the position of the Hall element 11 in the radial direction is also similarly configured within the range from the radial inner end of the permanent magnet 4 to a position away from 3B from the end. In addition, it is desired that the position of the Hall element 11 in the axial direction does not exceed the width (radial length) of the winding 7.

[0066] Here, the Hall element 11 can be arranged at two positions, radially inside and radially outside the stator 6. When the Hall element 11 is arranged radially inside the stator 6, the position of the Hall element 11 is arranged within the range from the position away from 3B (refer to arrow 41) from the axial upper end of the permanent magnet 4 to the position of the rotor 5. In addition, the position of the Hall element 11 in the radial direction is arranged within the range from the radial inner end of the permanent magnet 4 to the position away from 3B.

[0067] As described above, according to the above embodiment, when two orthogonal component signals for the electrical angle are generated, the error between the calculation result and the current rotation angle of the detection object can be suppressed.

[0068] Furthermore, according to the above-described embodiment, by deriving the difference between the detected signals, it is possible to remove the distortion of the waveform included in the signal. Furthermore, by deriving the difference between the detected signals, it is possible to remove the noise received from the outside.

[0069] Furthermore, according to the above-described embodiment, by detecting the leakage magnetic flux of the permanent magnet 4 provided in the motor 2 , it is not necessary to provide a magnet for detecting the rotation angle, and the Hall element 11 can be miniaturized.

[0070] Furthermore, according to the above embodiment, by increasing the height of the permanent magnet 4 , the distance between the stator 6 and the Hall element 11 is increased, and the influence of the magnetic flux generated by the stator 6 (winding 7 ) can be suppressed.

[0071] Furthermore, according to the above-described embodiment, by providing the Hall element 11 between the stators 6 , the influence of the magnetic flux generated by the stators 6 (windings 7 ) can be suppressed.

[0072] In addition, in the above-mentioned embodiment, the rotation angle calculation program is installed in the ROM 14, but it is not limited to this. The rotation angle calculation program of the present invention can also be provided in a manner recorded in a computer-readable storage medium. For example, the rotation angle calculation program of the present invention can also be provided in a manner recorded in an optical disk such as a CD (Compact Disc: Compressed Disc)-ROM or a DVD (Digital Versatile Disc: Digital Versatile Disc)-ROM. In addition, the rotation angle calculation program of the present invention can also be provided in a manner recorded in a semiconductor memory such as a USB (Universal Serial Bus: Universal Serial Bus) memory and a memory card. In addition, the rotation angle calculation device 10 can also download the rotation angle calculation program of the present invention from an external device connected to a communication line not shown in the figure through a communication line not shown in the figure.

[0073] The control unit and method described in the present disclosure may also be implemented by a special-purpose computer, which constitutes a processor programmed to execute one or more functions embodied by a computer program. Alternatively, the device and method described in the present disclosure may be implemented by a special-purpose computer that constitutes a processor through a dedicated hardware logic circuit. Alternatively, the device and method described in the present disclosure may also be implemented by one or more special-purpose computers that are composed of a combination of a processor that executes a computer program and one or more hardware logic circuits. In addition, the computer program may also be stored in a computer-readable non-temporary tangible recording medium as an instruction executed by a computer.

[0074] Although the present disclosure is described based on the embodiments, it should be understood that the present disclosure is not limited to the above-mentioned embodiments and structures. The present disclosure also includes various modifications and modifications within the equivalent range. In addition, various combinations and methods, and other combinations and methods containing only one element, above or below them, also belong to the scope and thought range of the present disclosure.

[0075] The following additional notes are disclosed regarding the present disclosure. (Note 1) A rotation angle calculation device, comprising: An acquisition unit (21) that acquires detection results of leakage magnetic flux generated from a permanent magnet (4) from three detection elements (11) disposed at positions that are offset by 120 electrical degrees relative to a permanent magnet (4) included in a detection object for detecting a rotation angle; a generating unit (22) for generating, using the three acquired detection results, orthogonal component signals representing two orthogonal components of the intensity of the leakage magnetic flux; and A calculation unit (23) calculates a rotation angle of the detection object using the orthogonal component signal. (Note 2) According to the rotation angle calculation device described in Supplementary Note 1, wherein: As the detection result, the acquisition unit acquires a signal U, a signal V, and a signal W each having a phase difference of 120 degrees. The generating unit generates a quadrature component signal X obtained from U-V and a quadrature component signal Y obtained from U+V-2W. (Note 3) A rotation angle calculation system, comprising: A rotation angle calculation device comprising Supplement 1 or Supplement 2 of the above-mentioned detection element; and An electric motor, the electric motor comprising a stator wound with windings and a rotor provided with the permanent magnet, The detection element is arranged at a position capable of detecting the leakage magnetic flux generated by the permanent magnet provided between the stator and the rotor. (Note 4) According to the rotation angle calculation system described in Appendix 3, When the radial width of the permanent magnet is represented by B, the detection element is arranged in a range from a position 3B away from one end of the permanent magnet to a position 3B away from the other end in the radial direction. (Note 5) According to the rotation angle calculation system described in Appendix 4, The detection element is further arranged in a range from a position away from 3B at the end of the permanent magnet in the axial direction. (Note 6) According to the rotation angle calculation system described in Supplementary Note 5, The detection element is arranged in a range that does not exceed a range of a winding wound around the stator in the axial direction. (Note 7) According to the rotation angle calculation system described in Appendix 3, When the axial height of the permanent magnet is defined as B, the detection element is arranged in the axial direction within a range from a position 3B away from one end of the permanent magnet to a position 3B away from the other end. (Note 8) According to the rotation angle calculation system described in Supplementary Note 7, wherein: The detection element is further arranged in a range from a position away from 3B at the end of the permanent magnet in the radial direction. (Note 9) The rotation angle calculation system according to any one of Supplement 3 to Supplement 8, wherein: When the axial length of the permanent magnet is M, the axial length of the stator is S, and the size of the radial gap between the permanent magnet and the stator is A, the axial length M of the permanent magnet is expressed by S+2A≤M≤1.3S. (Note 10) The rotation angle calculation system according to any one of Appendix 3 to Appendix 9, wherein: The detection element is disposed between windings wound around adjacent stators in a radial direction of the electric motor. (Note 11) A rotation angle calculation method, the rotation angle calculation method enables a computer to perform the following processing: The detection results of detecting the leakage magnetic flux generated from the permanent magnet included in the motor as the object of detecting the rotation angle are obtained from three detection elements respectively arranged at positions offset by 120 electrical degrees with respect to the permanent magnet included in the motor as the object of detecting the rotation angle, Using the three detection results obtained above, a quadrature component signal representing two orthogonal components of the intensity of the leakage magnetic flux is generated, The rotation angle of the motor is calculated using the quadrature component signal. (Note 12) A rotation angle calculation program, the rotation angle calculation program enables at least one processor to perform the following processing: The detection results of detecting the leakage magnetic flux generated from the permanent magnet included in the motor as the object of detecting the rotation angle are obtained from three detection elements respectively arranged at positions offset by 120 electrical degrees with respect to the permanent magnet included in the motor as the object of detecting the rotation angle, Using the three detection results obtained above, a quadrature component signal representing two orthogonal components of the intensity of the leakage magnetic flux is generated, The rotation angle of the motor is calculated using the quadrature component signal.

Claims

1. A rotation angle calculation device, comprising: An acquisition unit (21) that acquires detection results of leakage magnetic flux generated from a permanent magnet (4) from three detection elements (11) disposed at positions that are offset by 120 electrical degrees relative to a permanent magnet (4) included in a detection object for detecting a rotation angle; A generating unit (22), which generates an orthogonal component signal representing two orthogonal components using the three acquired detection results, wherein the two orthogonal components represent the intensity of the leakage magnetic flux; as well as A calculation unit (23) calculates a rotation angle of the detection object using the orthogonal component signal.

2. The rotation angle calculation device according to claim 1, characterized in that: As the detection result, the acquisition unit acquires a signal U, a signal V, and a signal W each having a phase difference of 120 degrees. The generating unit generates an orthogonal component signal X obtained from U-V and an orthogonal component signal Y obtained from U+V-2W.

3. A rotation angle calculation system, comprising: The rotation angle calculation device of claim 1 or claim 2 comprising the detection element; as well as An electric motor, the electric motor being provided with a stator wound with windings and a rotor provided with the permanent magnet, The detection element is arranged at a position capable of detecting the leakage magnetic flux generated by the permanent magnet provided between the stator and the rotor.

4. The rotation angle calculation system according to claim 3, characterized in that: When the radial width of the permanent magnet is represented by B, the detection element is arranged in a range from a position 3B away from one end of the permanent magnet to a position 3B away from the other end in the radial direction.

5. The rotation angle calculation system according to claim 4, characterized in that: The detection element is also arranged in the range from the end of the permanent magnet to a position away from 3B in the axial direction.

6. The rotation angle calculation system according to claim 5, characterized in that: The detection element is arranged in a range that does not exceed a range of a winding wire wound around the stator in the axial direction.

7. The rotation angle calculation system according to claim 3, characterized in that: When the axial height of the permanent magnet is defined as B, the detection element is arranged in the axial direction within a range from a position 3B away from one end of the permanent magnet to a position 3B away from the other end.

8. The rotation angle calculation system according to claim 7, characterized in that: The detection element is also arranged in a range from the end of the permanent magnet to a position away from 3B in the radial direction.

9. The rotation angle calculation system according to claim 3, characterized in that: When the axial length of the permanent magnet is M, the axial length of the stator is S, and the size of the radial gap between the permanent magnet and the stator is A, the axial length M of the permanent magnet is expressed by S+2A≤M≤1.3S.

10. The rotation angle calculation system according to claim 3, characterized in that: The detection element is arranged between windings wound around the adjacent stators in the radial direction of the electric motor.

11. A rotation angle calculation method, the rotation angle calculation method causing a computer to perform the following processing: A detection result of detecting a leakage magnetic flux generated from a permanent magnet included in a motor as a target for detecting a rotation angle is obtained from three detection elements respectively arranged at positions offset by 120 electrical degrees from the permanent magnet, Using the three detection results obtained, generating orthogonal component signals representing two orthogonal components, the two orthogonal components representing the intensity of the leakage magnetic flux, The rotation angle of the motor is calculated using the quadrature component signal.

12. A rotation angle calculation program, The rotation angle calculation program causes at least one processor to perform the following processing: A detection result of detecting a leakage magnetic flux generated from a permanent magnet included in a motor as a target for detecting a rotation angle is obtained from three detection elements respectively arranged at positions offset by 120 electrical degrees from the permanent magnet, Using the three detection results obtained, generating orthogonal component signals representing two orthogonal components, the two orthogonal components representing the intensity of the leakage magnetic flux, The rotation angle of the motor is calculated using the quadrature component signal.

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