Angle detection system based on magnetic method and detection method thereof

Abstract

The present application provides a magnetic angle detection system and a detection method thereof. The angle detection system with a magnet having a first magnetic track and a second magnetic track includes: an absolute angle calculation unit that calculates an absolute angle of a position of the magnet using first-1 digital signals, first-2 digital signals, second-1 digital signals, and second-2 digital signals, wherein the first-1 digital signals are converted from magnetic field signals of the first magnetic track, the first-2 digital signals are converted from magnetic field signals of the first magnetic track, the second-1 digital signals are converted from magnetic field signals of the second magnetic track, and the second-2 digital signals are converted from magnetic field signals of the second magnetic track, and wherein the first-1 digital signals and the first-2 digital signals are sine wave signals having a phase difference of 90 degrees, and the second-1 digital signals and the second-2 digital signals are sine wave signals having a phase difference of 90 degrees.

Description

Technical Field

[0001] This invention relates to a magnetically based angle detection system and method. Background Technology

[0002] A magnetically based angle detection system is used to detect the angle of a magnet attached to the rotor of a motor. In this case, a magnet with two tracks, TR1 and TR2, is used to improve the angle detection resolution. The magnetic encoder includes the magnet and the angle detection system that detects the angle generated as the magnet rotates.

[0003] Figure 1 This is an explanatory diagram of a magnetically based angle detection system with two magnetic tracks TR1 and TR2. The encoder chip C is preferably attached to a magnet having two annular magnetic tracks TR1 and TR2 at intervals. The encoder chip C also includes sensors H1 and H2 capable of detecting the magnetic fields of each of the two magnetic tracks TR1 and TR2.

[0004] When the motor rotates, the magnetic field changes. By detecting this changing magnetic field using sensors H1 and H2, the angular information generated as the magnet rotates, i.e., the rotation angle of the motor, can be detected. Summary of the Invention

[0005] The problem that the invention aims to solve

[0006] This invention was developed to solve the technical problems mentioned above. The purpose of this invention is to provide a magnetically based angle detection system and method that can detect the absolute angle of a motor when it stops and / or rotates with high resolution.

[0007] Methods for solving problems

[0008] An angle detection system utilizing a magnet having a first magnetic track and a second magnetic track includes an absolute angle calculation unit that calculates the absolute angle of the magnet's position using the following digital signals: a first-1 digital signal that detects the magnetic field signal of the first magnetic track and converts it into a digital signal; a first-2 digital signal that detects the magnetic field signal of the first magnetic track and converts it into a digital signal; a second-1 digital signal that detects the magnetic field signal of the second magnetic track and converts it into a digital signal; and a second-2 digital signal that detects the magnetic field signal of the second magnetic track and converts it into a digital signal. Simultaneously, the first-1 digital signal and the first-2 digital signal are sinusoidal wave signals with a 90-degree phase difference between them, and the second-1 digital signal and the second-2 digital signal are also sinusoidal wave signals with a 90-degree phase difference between them.

[0009] The absolute angle of the position of the magnet is constituted by at least one of the following interval values: a main interval value, which is the value of dividing one 360-degree rotation of the magnet into four 90-degree intervals, namely the first main interval to the fourth main interval; a sub-interval value, which is the value of dividing the first main interval to the fourth main interval into multiple intervals by using the phase difference between the magnetic field signal of the first magnetic track and the magnetic field signal of the second magnetic track; a first signal interval value, which is the value of dividing the magnetic field signal of the first magnetic track into four first signal intervals by using the sign of the first-1 digital signal and the sign of the first-2 digital signal; and a lower interval value, which is the value calculated by the first-1 digital signal and the first-2 digital signal for each of the first signal interval values.

[0010] Specifically, the absolute angle calculation unit includes: a main interval value calculator, which calculates the value of dividing one 360-degree rotation of the magnet into four 90-degree intervals, namely the first main interval to the fourth main interval, i.e., the main interval value; an angle output device, which outputs the absolute angle data of the position of the magnet including the main interval value; a first signal interval value calculator, which calculates the value of dividing the magnetic field signal of the first track into four first signal intervals using the sign of the first-1 digital signal and the sign of the first-2 digital signal, i.e., the first signal interval value; and a lower interval value calculator, which calculates the lower interval value for each of the first signal interval values ​​using the first-1 digital signal and the first-2 digital signal.

[0011] Meanwhile, the absolute angle calculation unit also includes: a first difference value calculator, which uses the first-1 digital signal, the first-2 digital signal, the second-1 digital signal, and the second-2 digital signal to calculate the phase difference between the magnetic field signal of the first track and the magnetic field signal of the second track, i.e., the first-1 difference value to the first-4 difference value; a data converter, which converts the first-1 difference value to the first-4 difference value into signed values, i.e., the first-1 signed difference value to the first-4 signed difference value; and an offset difference value calculator, which uses multiple difference values ​​from the first-1 signed difference value to the first-4 signed difference value to calculate the first-1 offset difference value to the first-4 offset difference value by 45 degrees, respectively.

[0012] The main interval value is calculated using the phase difference between the magnetic field signal of the first magnetic track and the magnetic field signal of the second magnetic track.

[0013] In addition, the absolute angle calculation unit mentioned above also includes a sub-interval value calculator, which calculates the value of the sub-interval from the first-1 sub-interval to the first-M sub-interval corresponding to one of the difference values ​​of the first-1 offset difference value to the first-4 offset difference value for each of the above main interval values.

[0014] Meanwhile, the aforementioned absolute angle calculation unit further includes: a first offset interval value calculator, which calculates a first signal interval value offset by one interval by offsetting the aforementioned first signal interval value by one first signal interval in the first direction; a second offset interval value calculator, which calculates a first signal interval value offset by two intervals by offsetting the aforementioned first signal interval value by two first signal intervals in the first direction; and a third offset interval value calculator, which calculates a first signal interval value offset by three intervals by offsetting the aforementioned first signal interval value by three first signal intervals in the first direction, wherein the aforementioned first direction is one of the left or right directions of the register used as the aforementioned first signal interval value calculator.

[0015] Additionally, it includes: a first signal interval period calculator, which calculates the first signal interval period of four repeated first signal intervals using the aforementioned first signal interval value; a second signal interval value calculator, which calculates the second signal interval value, which is the value of the four second signal intervals divided using the sign of the second-1 digital signal and the sign of the second-2 digital signal; and a second difference value calculator, which calculates the difference in position between the first signal interval value and the aforementioned second signal interval value, i.e., the second difference value, using one interval value from the un-offset first signal interval value, the aforementioned first signal interval value offset by 1 interval, the aforementioned first signal interval value offset by 2 intervals, and the aforementioned first signal interval value offset by 3 intervals. Simultaneously, the aforementioned main interval value is calculated using the aforementioned second difference value.

[0016] The aforementioned absolute angle calculation unit further includes a sub-interval value calculator, which calculates the values ​​of P intervals, i.e., sub-interval values, by dividing the aforementioned second difference value by the value of the aforementioned first signal interval period, such that the aforementioned first main interval to the aforementioned fourth main interval correspond to the values ​​of the 2-1 sub-interval to the 2-P sub-interval respectively.

[0017] Invention Effects

[0018] The magnetically based angle detection system and method of the present invention can detect the absolute angle when the motor stops and / or rotates with high resolution. Attached Figure Description

[0019] Figure 1 This is an illustration of a magnetically based angle detection system with two magnetic tracks.

[0020] Figure 2This is a structural diagram of a magnetically based angle detection system according to one embodiment.

[0021] Figure 3 This is a structural diagram of the absolute angle calculation unit in the first embodiment.

[0022] Figure 4 This is an explanatory diagram regarding the values ​​of the first signal interval.

[0023] Figure 5 It is a waveform diagram of the difference values ​​from 1-1 to 1-4, the signed difference values ​​from 1-1 to 1-4, and the offset difference values ​​from 1-1 to 1-4.

[0024] Figure 6 This is an explanatory diagram about subinterval values.

[0025] Figure 7 This is a structural diagram of the absolute angle calculation unit in the second embodiment.

[0026] Figure 8 This is an explanatory diagram of the first signal interval value calculator, the first offset interval value calculator, the second offset interval value calculator, and the third offset interval value calculator.

[0027] Figure 9 This is an explanatory diagram of the calculation process for the second difference value.

[0028] Figure 10 This is the waveform diagram of the calculation result of the second difference value.

[0029] Symbol Explanation

[0030] 1000: Angle Detection System

[0031] 100: Sensor device; 200: Angle detection device

[0032] H11: Sensor 1-1 H12: Sensor 1-2

[0033] H21: Sensor 2-1 H22: Sensor 2-2

[0034] 210: Analog-to-digital converter; 230a, 230b: Absolute angle calculation unit

[0035] 231a, 231b: Main Interval Value Calculator

[0036] 232a, 232b: Calculator for the first signal interval value

[0037] 233a: First Difference Value Calculator; 234a: Data Converter

[0038] 235a: Offset Difference Calculator

[0039] 237a, 237b: Subinterval Value Calculator

[0040] 233b_1: Calculator for the first offset interval value

[0041] 233b_2: Calculator for the second offset interval value

[0042] 233b_3: Calculator for the 3rd Offset Interval Value

[0043] 234b: First Signal Interval Period Calculator

[0044] 235b: Second Difference Value Calculator 236b: Second Signal Interval Value Calculator

[0045] 238a, 238b: Lower-level interval value calculator; 239a, 239b: Angle output device Detailed Implementation

[0046] Hereinafter, with reference to the accompanying drawings, a magnetically based angle detection system and detection method according to embodiments of the present invention will be described in detail.

[0047] The following embodiments of the present invention are merely illustrative and are not intended to limit the scope of the invention. Features that can be easily derived by those skilled in the art from the detailed description and embodiments of the present invention are all within the scope of the present invention.

[0048] A magnetically based angle detection system is used to detect the angle of a magnet attached to the rotor of a motor. In this case, to detect the angle and improve resolution, a magnetically based angle detection system is used... Figure 1 This type of magnet has two annular tracks, TR1 and TR2. The magnetic encoder includes the magnet and an angle detection system that detects the angle generated as the magnet rotates.

[0049] That is, the magnet used in the magnetic encoder for detecting angles of the present invention preferably includes: an annular first magnetic track TR1, which has a shape in which N poles and S poles are alternately and repeatedly connected; and an annular second magnetic track TR2, which is connected to the inner or outer side of the first magnetic track TR1 and is formed by connecting multiple unit poles. Alternatively, the second magnetic track TR2 is formed to be connected to the upper or lower side of the first magnetic track TR1.

[0050] At the same time, the multiple unit poles are of the same size and possess one of several polarities, including N-pole and S-pole. That is, the unit poles are either N-pole or S-pole.

[0051] However, with Figure 1In contrast, the magnets used in the magnetic encoder for detecting angles of the present invention are preferably as follows: the number of pairs of N poles and S poles in the two magnetic tracks TR1 and TR2 are different, so that when the N poles and S poles in the two magnetic tracks TR1 and TR2 pass the same position, as the angle increases, the N poles and S poles in the two magnetic tracks TR1 and TR2 gradually shift apart.

[0052] Specifically, in the magnetic encoder used in the present invention, when the N and S poles of the U pair are alternately and repeatedly connected in the first magnetic track TR1, and the N and S poles of the W pair are alternately and repeatedly connected in the second magnetic track TR2, if U and W are different from each other, then according to the rotation of the motor, the positions of the unit poles of the N or S poles of the first magnetic track TR1 and the second magnetic track TR2 gradually shift, resulting in a phase difference between the magnetic field signals of the first magnetic track TR1 and the second magnetic track TR2. For example, the first magnetic track TR1 and the second magnetic track TR2 are designed with U = 32 and W = 31 respectively.

[0053] Figure 2 A structural diagram of a magnetically based angle detection system 1000 according to an embodiment is shown. The magnetically based angle detection system 1000 according to an embodiment uses... Figure 1 The encoder chip C shown is a representation of its form.

[0054] like Figure 2 As shown, an embodiment of a magnetically based angle detection system 1000 includes a sensor device 100 and an angle detection device 200.

[0055] The sensor device 100 is configured to include at least one first-1 sensor H11, at least one first-2 sensor H12, at least one second-1 sensor H21, and at least one second-2 sensor H22.

[0056] As at least one first-1 sensor H11, at least one first-2 sensor H12, at least one second-1 sensor H21 and at least one second-2 sensor H22 included in the sensor device 100, various magnetic sensors such as Hall sensors and magnetoresistive elements can be used.

[0057] At least one first-1 sensor H11 and at least one first-2 sensor H12 detect the magnetic field signal of the first magnetic track TR1, respectively. At this time, assuming that at least one first-1 sensor H11 detects the magnetic field signal of the first magnetic track TR1 corresponding to a sine wave signal, at least one first-2 sensor H12 detects the magnetic field signal of the first magnetic track TR1 corresponding to a cosine wave signal. That is, the outputs of at least one first-1 sensor H11 and at least one first-2 sensor H12 are sine wave signals, and at least one first-1 sensor H11 and at least one first-2 sensor H12 are configured with a 90-degree phase difference between them.

[0058] For reference, when detecting the magnetic field signal of the first magnetic track TR1 in the form of sine and cosine signals, it is preferable to configure two first-1 sensors H11 and two first-2 sensors H12 respectively in the case of using differential signals in the angle detection device 200.

[0059] Similarly, at least one second-1 sensor H21 and at least one second-2 sensor H22 detect the magnetic field signal of the second magnetic track TR2. Here, assuming that at least one second-1 sensor H21 detects the magnetic field signal of the second magnetic track TR2 corresponding to a sine wave signal, at least one second-2 sensor H22 detects the magnetic field signal of the second magnetic track TR2 corresponding to a cosine wave signal. That is, the outputs of at least one second-1 sensor H21 and at least one second-2 sensor H22 are sine wave signals, and at least one second-1 sensor H21 and at least one second-2 sensor H22 are configured with a 90-degree phase difference.

[0060] For reference, when detecting the magnetic field signal of the second magnetic track TR2 in the form of sine and cosine signals, it is preferable to configure two second-1 sensors H21 and two-2 sensors H22 respectively in the angle detection device 200 when using differential signals.

[0061] The angle detection device 200 comprises an analog-to-digital converter 210 and absolute angle calculation units 230a and 230b. The analog-to-digital converter 210 and the absolute angle calculation units 230a and 230b each comprise at least one of a circuit, a processor, and a memory.

[0062] The analog-to-digital converter 210 receives the analog signals output from multiple sensors H11 and H12 and converts them into digital signals, namely, the first-1 digital signal and the first-2 digital signal, for output. Simultaneously, the analog-to-digital converter 210 also receives the analog signals output from multiple sensors H21 and H22 and converts them into digital signals, namely, the second-1 digital signal and the second-2 digital signal, for output. The analog-to-digital converter 210 has independent analog-to-digital converters for each of the first-1 digital signal and the first-2 digital signal, and for each of the second-1 digital signal and the second-2 digital signal. Alternatively, the analog-to-digital converter 210 can be shared by using a multiplexer to perform multiple conversions of the first-1 digital signal and the first-2 digital signal, and for each of the second-1 digital signal and the second-2 digital signal, within a single analog-to-digital converter.

[0063] Specifically, the analog-to-digital converter 210 receives the outputs of at least one first-1 sensor H11 and at least one first-2 sensor H12 (i.e., analog signals) from the magnetic field signal detected by the first magnetic track TR1, and converts them into digital signals, namely, the first-1 digital signal and the first-2 digital signal, for output. Simultaneously, the first-1 digital signal and the first-2 digital signal are sinusoidal signals with a 90-degree phase difference between them.

[0064] Similarly, the analog-to-digital converter 210 receives the outputs of at least one second-1 sensor H21 and at least one second-2 sensor H22 (i.e., analog signals) from the magnetic field signal detected by the second magnetic track TR2, and converts them into digital signals, namely, the second-1 digital signal and the second-2 digital signal, for output. The second-1 digital signal and the second-2 digital signal are sinusoidal signals with a 90-degree phase difference.

[0065] The absolute angle calculation units 230a and 230b are used to calculate the absolute angle of the magnet's position using the first-1 digital signal, the first-2 digital signal, the second-1 digital signal, and the second-2 digital signal. The absolute angle of the magnet's position refers to the angle of rotation from the magnet's reference position.

[0066] The absolute angle of the magnet's position is constituted by at least one of the following interval values: the value of dividing one 360-degree rotation of the magnet into four 90-degree intervals, namely the first main interval to the fourth main interval, i.e., the main interval value; the sub-interval value of dividing the first main interval to the fourth main interval into multiple intervals using the phase difference between the magnetic field signals of the first track and the magnetic field signals of the second track; the value of dividing the magnetic field signal of the first track into four first signal intervals using the signs of the first-1 digital signal and the first-2 digital signal, i.e., the first signal interval value; and the value calculated by using the first-1 digital signal and the first-2 digital signal for each first signal interval value, i.e., the lower interval value.

[0067] Figure 3 A structural diagram of the absolute angle calculation unit 230a of the first embodiment is shown.

[0068] like Figure 3 As shown, the absolute angle calculation unit 230a of the first embodiment is composed of a main interval value calculator 231a, a first signal interval value calculator 232a, a first difference value calculator 233a, a data converter 234a, an offset difference value calculator 235a, a sub-interval value calculator 237a, a lower interval value calculator 238a, and an angle output device 239a.

[0069] For reference, when the motor stops rotating, the absolute angle calculation unit 230a of the first embodiment is used to calculate the rotation angle of the motor at the stopped position.

[0070] The principal interval value calculator 231a calculates the principal interval value by dividing one 360-degree rotation of the magnet into four 90-degree intervals, namely the first to the fourth principal intervals. For reference, various methods are used to calculate the principal interval value.

[0071] Meanwhile, the first signal interval value calculator 232a calculates the value of dividing the magnetic field signal of the first magnetic track TR1 into four first signal intervals using the sign of the first-1 digital signal and the sign of the first-2 digital signal.

[0072] Figure 4 A diagram illustrating the values ​​for the first signal interval is shown.

[0073] like Figure 4 As shown, the value of the first signal interval is the value of dividing the magnetic field signal of the first track TR1 into four first signal intervals by combining the symbols of the first-1 digital signal and the first-2 digital signal.

[0074] For example, assuming the first signal interval is set to a 2-bit signal, if both the sign of the first-1 digital signal and the sign of the first-2 digital signal are positive, the first signal interval value is set to '00'; if the sign of the first-1 digital signal and the sign of the first-2 digital signal are positive and negative respectively, the first signal interval value is set to '01'. Similarly, if both the sign of the first-1 digital signal and the sign of the first-2 digital signal are negative, the first signal interval value is set to '10'; if the sign of the first-1 digital signal and the sign of the first-2 digital signal are negative and positive respectively, the first signal interval value is set to '11'.

[0075] The first difference value calculator 233a uses the first-1 digital signal, the first-2 digital signal, the second-1 digital signal, and the second-2 digital signal to calculate the first-1 difference value to the first-4 difference value into an unsigned value.

[0076] The difference values ​​from 1-1 to 1-2 are calculated using the preset [Formula 1].

[0077]

Formula 1

[0078] P(1-1)={SIN(α)-SIN(β)} 2 +{COS(α)-COS(β)} 2

[0079] P(1-2)={SIN(α)-COS(β)} 2 +{COS(α)-SIN(β_B)} 2

[0080] In [Equation 1], P1-1 to P1-2 represent the first-1 difference value to the first-2 difference value, SIN(α) represents the first-1 digital signal, COS(α) represents the first-2 digital signal, SIN(β) represents the second-1 digital signal, COS(β) represents the second-2 digital signal, and β_B represents the signal that inverts β, i.e., -β.

[0081] Meanwhile, the 1st to 3rd difference value is a signal that inverts the 1st to 1st difference value, and the 1st to 4th difference value is a signal that inverts the 1st to 2nd difference value. That is, the 1st to 4th difference values ​​are values ​​with a phase difference of 90 degrees.

[0082] For reference, when using trigonometric function equations, the difference value of the first - 1 can be represented as shown in [Equation 2] below.

[0083]

Formula 2

[0084] P(1-1)={SIN(α)-SIN(β)}2 +{COS(α)-COS(β)} 2 =SIN 2 (α)-2SIN(α)SIN(β)+SIN 2 (β)+COS 2 (α)-2COS(α)COS(β)+COS 2 (β)=2-2{COS(α)COS(β)+SIN(α)SIN(β)}=2{1-COS(α-β)}

[0085] As shown in [Equation 2], the difference values ​​from 1-1 to 1-4 are the phase difference (α-β) between the magnetic field signal of the first magnetic track TR1 and the magnetic field signal of the second magnetic track TR2, respectively.

[0086] The data converter 234a converts the first-1 difference value to the first-4 difference value into signed values, namely the first-1 signed difference value to the first-4 signed difference value.

[0087] Specifically, the signed difference values ​​from 1-1 to 1-4 are calculated respectively using [Equation 3] below.

[0088]

Formula 3

[0089] SignP(1-1) = P(1-1) - P1(SUM)

[0090] SignP(1-2) = P(1-2) - P1(SUM)

[0091] SignP(1-3) = P(1-3) - P1(SUM)

[0092] SignP(1-4) = P(1-4) - P1(SUM)

[0093] In [Equation 3], SignP(1-1) to SignP(1-4) represent the first to fourth signed difference values, respectively. P(1-3) represents the first to third difference value, P(1-4) represents the first to fourth difference value, and P1(SUM) is shown in [Equation 4] below.

[0094]

Formula 4

[0095]

[0096] The offset difference calculator 235a uses multiple difference values ​​from the first-1 signed difference value to the first-4 signed difference value to calculate the first-1 offset difference value to the first-4 offset difference value by phase shifting the first-1 difference value to the first-4 difference value by 45 degrees.

[0097] Specifically, the offset difference values ​​from 1-1 to 1-4 are calculated as shown in [Equation 5] below.

[0098]

Formula 5

[0099] ShiftP(1-1)=SignP(1-4)-SignP(1-3)

[0100] ShiftP(1-2)=B_SignP(1-4)-SignP(1-3)

[0101] ShiftP(1-3)=SignP(1-4)+SignP(1-3)

[0102] ShiftP(1-4)=B_SignP(1-4)+SignP(1-3)

[0103] In [Equation 5], ShiftP(1-1) to ShiftP(1-4) represent the offset difference values ​​from 1-1 to 1-4, respectively. Meanwhile, B_SignP(1-4) represents the value of inverting the signed difference value from 1 to 4.

[0104] Figure 5 The waveforms represent the first-1 difference value to the first-4 difference value, the first-1 signed difference value to the first-4 signed difference value, and the first-1 offset difference value to the first-4 offset difference value calculated by the first difference value calculator 233a, the data converter 234a, and the offset difference value calculator 235a, respectively.

[0105] like Figure 5 As shown, the difference values ​​1-1 to 1-4 have maximum values ​​at 90 degrees, 180 degrees, 270 degrees and 360 degrees respectively during one rotation of the magnet in the entire 360 ​​degrees, and form a sine wave shape with a 360-degree cycle.

[0106] For reference, the main interval value is calculated using the values ​​calculated from the 1-1 difference value to the 1-4 difference value. Specifically, the main interval value is calculated using the values ​​from the 1-1 difference value to the 1-4 difference value, i.e., the 1-1 signed difference value to the 1-4 signed difference value. However, the 1-1 signed difference value to the 1-4 signed difference value also includes the phase difference between the magnetic field signal of track 1 TR1 and the magnetic field signal of track 2 TR2. That is, the main interval value is calculated using the value that includes the phase difference between the magnetic field signal of track 1 and the magnetic field signal of track 2.

[0107] For example, the sign of each of the signed difference values ​​from 1-1 to 1-4 is taken as 1 bit and the entire 4-bit value is compared with the reference value 1 to reference value 4, and the main interval value is set as '00', '01', '10', and '11' in 2 bits.

[0108] The sub-interval value calculator 237a calculates the sub-interval value for each main interval value such that one of the difference values ​​from the 1-1 offset difference value to the 1-4 offset difference value corresponds to the value in the 1-1 sub-interval to the 1-M sub-interval. Here, M is a natural number greater than 2.

[0109] Figure 6 A diagram illustrating the values ​​of the sub-intervals is shown.

[0110] That is, the sub-interval value relative to the first main interval causes the offset difference value of the first-1 to correspond to 3 bits, i.e., 8 sub-intervals, i.e., the first-1 sub-interval to the first-8 sub-interval.

[0111] That is, the sub-interval values ​​are represented by 3 bits from sub-interval 1-1 to sub-interval 1-8 as '000' to '111'. For example, if the 1-1 offset difference value corresponds to the 1-1 sub-interval, the sub-interval value is '000'.

[0112] Similarly, the sub-interval value relative to the second main interval causes the first-second offset difference value to correspond to 3 bits, i.e., 8 sub-intervals, i.e., sub-interval 1-1 to sub-interval 1-8.

[0113] That is, the sub-intervals to be assigned are determined based on the magnitude of the offset difference values ​​from 1-1 to 1-4.

[0114] The lower-order interval value calculator 238a calculates the value obtained by using the first-1 digital signal and the first-2 digital signal for each first signal interval value, which is the lower-order interval value. That is, the lower-order interval value is the value of dividing each first signal interval value into K lower-order angle values. Here, K is a natural number greater than 4.

[0115] Specifically, regarding the lower-level intervals, for each first signal interval value, each lower-level interval is represented by K lower-level angle values. For example, if there are 4 first signal intervals, the values ​​of the first to fourth lower-level intervals are calculated. Simultaneously, the values ​​of the first to fourth lower-level intervals are represented using Y bits. When the first signal interval value is '00', the first lower-level interval value is used, and K is 2. Y That is, the lower interval value is the value obtained by dividing the first signal interval value into K lower angle values. When Y is 16, K is 2. 16 .

[0116] The lower interval values ​​are calculated from the first signal interval value to the fourth lower interval value as shown in [Equation 6] below. For example, when the first signal interval value is '00', the first lower interval value is used; when the first signal interval value is '01', the second lower interval value is used; when the first signal interval value is '10', the third lower interval value is used; and when the first signal interval value is '11', the fourth lower interval value is used.

[0117]

Formula 6

[0118] L(1-1)=SIN(α)+COS(α_B)

[0119] L(1-2)=SIN(α_B)+COS(α_B)

[0120] L(1-3)=SIN(α)+COS(α_B)

[0121] L(1-4)=SIN(α_B)+COS(α_B)

[0122] In [Equation 6], L(1-1) to L(1-4) represent the values ​​of the first to fourth lower intervals, respectively. Meanwhile, α_B represents the signal that inverts α, i.e., -α.

[0123] Angle output device 239a outputs absolute angle data of the position of the magnet. For example, if 32 pairs of N poles and S poles are alternately connected repeatedly in the first track TR1 and 31 pairs of N poles and S poles are alternately connected repeatedly in the second track TR2, the absolute angle data calculated by angle output device 239a consists of the following bits.

[0124] (1) Main interval value: The top 2 bits are used to divide the 360-degree rotation of the magnet into 4 90-degree intervals, namely the values ​​of the first main interval to the fourth main interval.

[0125] (2) Sub-interval value: The lower bits that constitute the main interval value, each main interval value consists of 3 bits of data. That is, the absolute angle is calculated with a resolution of 11.25 degrees, which is the result of dividing a main interval of 90 degrees by 8.

[0126] (3) First signal interval value: The first signal interval value is calculated using the sign of the first-1 digital signal and the sign of the first-2 digital signal, and forms the lower 2 bits of the sub-interval value. That is, the absolute angle is calculated with a resolution of 2.8125 degrees, which is 360 degrees divided by (32 pairs of poles × 4 first signal intervals).

[0127] (4) Lower interval value: The value calculated using the first-1 digital signal and the first-2 digital signal for each first signal interval value. The lower 16 bits constitute the first signal interval value.

[0128] Figure 7 A structural diagram of the absolute angle calculation unit 230b of the second embodiment is shown.

[0129] like Figure 7 As shown, the absolute angle calculation unit 230b of the second embodiment is composed of a main interval value calculator 231b, a first signal interval value calculator 232b, a first offset interval value calculator 233b_1, a second offset interval value calculator 233b_2, a third offset interval value calculator 233b_3, a first signal interval period calculator 234b, a second difference value calculator 235b, a second signal interval value calculator 236b, a sub-interval value calculator 237b, a lower interval value calculator 238b, and an angle output device 239b.

[0130] For reference, when the motor is rotating, the absolute angle calculation unit 230b of the second embodiment is used to calculate the rotation angle of the motor at that rotation position.

[0131] Meanwhile, if the various structures of the absolute angle calculation unit 230b of the second embodiment are used with the same names as the various structures of the absolute angle calculation unit 230a of the first embodiment, then without further explanation, the features of all the structures with the same names as the absolute angle calculation unit 230a of the first embodiment are included.

[0132] The 231b main interval value calculator calculates the main interval value by dividing one 360-degree rotation of a magnet into four 90-degree intervals, namely the first to the fourth main intervals. For reference, the main interval value is calculated using various methods.

[0133] Figure 8Explanatory diagrams are shown regarding the first signal interval value calculator 232b, the first offset interval value calculator 233b_1, the second offset interval value calculator 233b_2 to the third offset interval value calculator 233b_3.

[0134] The first signal interval value calculator 232b calculates and stores the first signal interval values, which divide the magnetic field signal of the first track TR1 into four first signal intervals using the sign of the first-1 digital signal and the sign of the first-2 digital signal. When represented in 2 bits, the first signal interval values ​​are, for example, '00', '01', '10', and '11'.

[0135] The first offset interval value calculator 233b_1 calculates the first signal interval value by offsetting the first signal interval value by one first signal interval in the first direction. Simultaneously, the second offset interval value calculator 233b_2 calculates the first signal interval value by offsetting the first signal interval value by two first signal intervals in the first direction. Furthermore, the third offset interval value calculator 233b_3 calculates the first signal interval value by offsetting the first signal interval value by three first signal intervals in the first direction.

[0136] The first direction is either the left or right direction of the register used as the first signal interval value calculator 232b.

[0137] The second signal interval value calculator 236b calculates and stores the second signal interval values, which divide the magnetic field signal of the second track TR2 into four second signal intervals using the sign of the second-1 digital signal and the sign of the second-2 digital signal. When represented in 2 bits, the second signal interval values ​​are, for example, '00', '01', '10', and '11'.

[0138] That is, the value of the second signal interval is also set in the same way as the value of the first signal interval.

[0139] The first signal interval cycle calculator 234b calculates the first signal interval cycle by using the first signal interval value to repeat four first signal intervals. For example, the first signal interval cycle is calculated using the time point from the current '00' of the first signal interval value to the time point from the next '00'. By calculating the first signal interval cycle, the motor's rotational speed can be reflected, allowing for adjustments based on the motor's speed.

[0140] The second difference value calculator 235b calculates the difference in position between the first signal interval value and the second signal interval value, i.e., the second difference value, by using one interval value from the first signal interval value without offset, the first signal interval value offset by 1 interval, the first signal interval value offset by 2 intervals, and the first signal interval value offset by 3 intervals.

[0141] Figure 9 This is an explanatory diagram of the calculation process for the second difference value. Figure 10 The waveform of the calculation result of the second difference value is shown.

[0142] The second difference value corresponds to the phase difference between the magnetic field signals of track 1 TR1 and track 2 TR2. That is, the second difference value is generated by the difference between the logarithm of the N and S poles constituting track 1 TR1 and the logarithm of the N and S poles constituting track 2 TR2. When the second difference value is calculated to be equivalent to 90 degrees, the second difference value is further calculated using another interval value, based on one of the following intervals: the un-offset first signal interval value, the first signal interval value offset by one interval, the first signal interval value offset by two intervals, and the first signal interval value offset by three intervals.

[0143] That is, assuming there are 32 pairs of N and S poles constituting the first magnetic track TR1, and 31 pairs of N and S poles constituting the second magnetic track TR2, the second difference value is calculated using the first signal interval value until the second difference value reaches the eighth pair of magnets in the first magnetic track TR1 at 90 degrees. When the second difference value reaches 90 degrees, the second difference value is calculated using the first signal interval value shifted by 3 intervals until the second difference value reaches the 16th pole pair in the first magnetic track TR1 at 90 degrees. Similarly, when the second difference value reaches 90 degrees, the second difference value is calculated using the first signal interval value shifted by 2 intervals until the second difference value reaches the 24th pole pair in the first magnetic track TR1 at 90 degrees. Finally, when the second difference value becomes 90 degrees, the second difference value is calculated using the first signal interval value offset by 1 interval, and the calculation continues until the second difference value becomes 90 degrees for the 32nd pole pair of the first magnetic track TR1.

[0144] In summary, the second difference value shows the recurring pattern of a linear function with a maximum value at 90 degrees. The four 90-degree intervals are calculated by taking one of the interval values ​​of the first and second signal intervals, the first and second signal intervals offset by one interval, the first and second signal intervals offset by two intervals, and the first and second signal intervals offset by three intervals, respectively.

[0145] The principal interval values ​​are calculated using the second difference value. For example, the second difference value is set at 90-degree intervals, and the principal interval values ​​are set using the first to fourth principal intervals. That is, the interval from the initial 0 degrees to 90 degrees is set as the first principal interval, and the interval from the next 0 degrees to 90 degrees is set as the second principal interval. The first to fourth principal intervals are set to '00', '01', '10', and '11' using 2-bit principal interval values.

[0146] The sub-interval value calculator 237b calculates the values ​​of P intervals, from the first main interval to the fourth main interval, that correspond to the sub-intervals from the second difference value to the period of the first signal interval, i.e., the sub-interval values. In other words, the sub-interval values ​​are the values ​​that normalize the second difference value independently of the motor speed by dividing it by the period of the first signal interval. Here, P is a natural number greater than 2.

[0147] For example, the sub-interval value is normalized relative to the first main interval and the second difference value is mapped to eight 3-bit sub-intervals, namely sub-intervals 2-1 to 2-8. That is, the sub-interval value uses 3 bits to represent sub-intervals 2-1 to 2-8 as '000' to '111'. Meanwhile, when the normalized second difference value corresponds to sub-interval 2-1, the sub-interval value is '000'. In other words, the assigned sub-interval is determined by the magnitude of the normalized second difference value.

[0148] The lower interval value calculator 238b calculates the value calculated by the first-1 digital signal and the first-2 digital signal for each first signal interval value, which is the lower interval value.

[0149] The angle outputter 239b outputs absolute angle data in bits, including the main interval value, the sub-interval value, the first signal interval value, and the lower interval value.

[0150] An example of a magnetically based angle detection method will be described.

[0151] One embodiment of the magnetically based angle detection method utilizes the aforementioned angle detection system 1000, and therefore, unless otherwise specified, includes all the features of the angle detection system 1000. Furthermore, the various steps of one embodiment of the magnetically based angle detection method are implemented using at least one or a combination of analog circuits, digital circuits, a processor, and a memory.

[0152] The magnetic angle detection method includes: a first analog-to-digital conversion step S10, receiving the outputs of at least one first-1 sensor H11 and at least one first-2 sensor H12 that detect the magnetic field signal of the first magnetic track TR1, and outputting digital signals, namely the first-1 digital signal and the first-2 digital signal; a second analog-to-digital conversion step S20, receiving the outputs of at least one second-1 sensor H21 and at least one second-2 sensor H22 that detect the magnetic field signal of the second magnetic track TR2, and outputting digital signals, namely the second-1 digital signal and the second-2 digital signal; and absolute angle calculation steps S30A and S30B, using the first-1 digital signal, the first-2 digital signal, the second-1 digital signal, and the second-2 digital signal to calculate the absolute angle of the magnet's position.

[0153] That is, in the first analog-to-digital conversion step S10, analog signals from multiple sensors H11 and H12 that detect the magnetic field signal of the first magnetic track TR1 are received and converted into digital signals; in the second analog-to-digital conversion step S20, analog signals from multiple sensors H21 and H22 that detect the magnetic field signal of the second magnetic track TR2 are received and converted into digital signals.

[0154] Meanwhile, digital signal 1-1 and digital signal 1-2 are sinusoidal signals with a 90-degree phase difference between them. Similarly, digital signal 2-1 and digital signal 2-2 are sinusoidal signals with a 90-degree phase difference between them.

[0155] The absolute angle of the magnet's position is constituted by at least one of the following interval values: a main interval value, which is the value of dividing one 360-degree rotation of the magnet into four 90-degree intervals, namely the first main interval to the fourth main interval; a sub-interval value, which is the value of dividing the first main interval to the fourth main interval into multiple intervals using the phase difference between the magnetic field signals of the first track and the magnetic field signals of the second track; a first signal interval value, which is the value of dividing the magnetic field signal of the first track into four first signal intervals using the signs of the first-1 digital signal and the first-2 digital signal; and a lower interval value, which is the value calculated by the first-1 digital signal and the first-2 digital signal for each first signal interval value.

[0156] The absolute angle calculation step S30A of the first embodiment will be described.

[0157] The absolute angle calculation step S30A of the first embodiment utilizes the absolute angle calculation unit 230a of the first embodiment described above, and therefore, unless otherwise explained, includes all the features of the absolute angle calculation unit 230a of the first embodiment.

[0158] The absolute angle calculation step S30A in the first embodiment includes the main interval value calculation step S31A, the first signal interval value calculation step S32A, the first difference value calculation step S33A, the data conversion step S34A, the offset difference value calculation step S35A, the sub-interval value calculation step S36A, the lower interval value calculation step S37A, and the angle output step S38A.

[0159] In step S31A, the main interval value is calculated by dividing the magnet's 360-degree rotation into four 90-degree intervals, specifically the values ​​of the first to fourth main intervals. For reference, the main interval value is calculated using various methods.

[0160] In step S32A of calculating the first signal interval value, the value of dividing the magnetic field signal of the first magnetic track TR1 into four first signal intervals using the sign of the first-1 digital signal and the sign of the first-2 digital signal is calculated, which is the first signal interval value.

[0161] Simultaneously, in the first difference value calculation step S33A, the phase difference values ​​between the magnetic field signals of the first track TR1 and the second track TR2, namely the first-1 difference value to the first-4 difference value, are calculated using the first-1 digital signal, the first-2 digital signal, the second-1 digital signal, and the second-2 digital signal. The first-1 difference value to the first-4 difference value are then calculated as unsigned values.

[0162] In data conversion step S34A, the difference values ​​1-1 to 1-4 are converted into signed values, namely, the signed difference values ​​1-1 to 1-4. In offset difference value calculation step S35A, multiple difference values ​​from the signed difference values ​​1-1 to 1-4 are used to calculate the offset difference values ​​1-1 to 1-4, which are phase-shifted by 45 degrees respectively.

[0163] For reference, the main interval value is calculated using the values ​​calculated from the first-1 difference value to the first-4 difference value. Specifically, the main interval value is calculated using the values ​​from the first-1 difference value to the first-4 difference value, i.e., the first-1 signed difference value to the first-4 signed difference value. However, the first-1 signed difference value to the first-4 signed difference value also includes the phase difference between the magnetic field signal of track 1 TR1 and the magnetic field signal of track 2 TR2. That is, the main interval value is calculated using the value that includes the phase difference between the magnetic field signal of track 1 and the magnetic field signal of track 2.

[0164] In the sub-interval value calculation step S36A, for each main interval value, a difference value is calculated such that one of the difference values ​​from the 1-1 offset difference value to the 1-4 offset difference value corresponds to the value of the 1-1 sub-interval to the 1-M sub-interval, i.e., the sub-interval value. M is a natural number greater than 2.

[0165] In step S37A, the lower-order interval value is calculated using the first-1 digital signal and the first-2 digital signal for each first signal interval value. The lower-order interval value is the value of dividing each first signal interval value into K lower-order angle values. Here, K is a natural number greater than 4.

[0166] In the angle output step S38A, the absolute angle data of the magnet's position, including the main interval value, is output. Specifically, the absolute angle data calculated in the angle output step S38A includes the main interval value, the sub-interval value, the first signal interval value, and the bits of the lower interval value.

[0167] The absolute angle calculation step S30B of the second embodiment will be described.

[0168] In the absolute angle calculation step S30B of the second embodiment, the absolute angle calculation unit 230b of the second embodiment described above is used. Therefore, unless otherwise explained, all the features of the absolute angle calculation unit 230b of the second embodiment are also included.

[0169] The absolute angle calculation step S30B in the second embodiment includes the main interval value calculation step S31B, the first signal interval value calculation step S32B, the first offset interval value calculation step S33B_1, the second offset interval value calculation step S33B_2, the third offset interval value calculation step S33B_3, the first signal interval period calculation step S34B, the second signal interval value calculation step S35B, the second difference value calculation step S36B, the sub-interval value calculation step S37B, the lower interval value calculation step S38B, and the angle output step S39B.

[0170] In step S31B of calculating the main interval value, the value of dividing the magnet's 360-degree rotation into four 90-degree intervals, namely the first main interval to the fourth main interval, is calculated.

[0171] Meanwhile, in the first signal interval value calculation step S32B, the value of dividing the magnetic field signal of the first magnetic track TR1 into 4 first signal intervals using the sign of the first-1 digital signal and the sign of the first-2 digital signal is calculated, namely the first signal interval value.

[0172] In the first offset interval value calculation step S33B_1, the first signal interval value is offset by one first signal interval in the first direction to calculate the first signal interval value offset by one interval. Simultaneously, in the second offset interval value calculation step S33B_2, the first signal interval value is offset by two first signal intervals in the first direction to calculate the first signal interval value offset by two intervals. In the third offset interval value calculation step S33B_3, the first signal interval value is offset by three first signal intervals in the first direction to calculate the first signal interval value offset by three intervals. The first direction is either the left or right direction of the register used in the calculation of the first signal interval value.

[0173] In step S34B of calculating the period of the first signal interval, the period of the first signal interval is calculated by using the value of the first signal interval for four repeated first signal intervals.

[0174] In the second signal interval value calculation step S35B, the values ​​of the four second signal intervals, divided using the signs of the second-1 digital signal and the second-2 digital signal, are calculated, i.e., the second signal interval values. Simultaneously, in the second difference value calculation step S36B, the difference between the changed positions of the first signal interval value and the second signal interval value is calculated sequentially using one of the following interval values: the un-offset first signal interval value, the first signal interval value offset by one interval, the first signal interval value offset by two intervals, and the first signal interval value offset by three intervals.

[0175] At the same time, the main interval value is calculated using the second difference value.

[0176] In the sub-interval value calculation step S37B, the values ​​of P intervals, which correspond to the 2nd difference value and the period of the 1st signal interval, are calculated by dividing the 2nd difference value by the period of the 1st signal interval. These values ​​are the sub-interval values. Here, P is a natural number greater than 2.

[0177] In step S38B, the lower-level interval value is calculated for each first signal interval value using the first-1 digital signal and the first-2 digital signal. The lower-level interval value is the value of dividing each first signal interval value into K lower-level angle values. K is a natural number greater than 4.

[0178] In the angle output step S39B, the absolute angle data of the magnet's position, including the main interval value, is output. Specifically, the absolute angle data calculated in the angle output step S39B includes the main interval value, the sub-interval value, the first signal interval value, and the bits of the lower interval value.

[0179] As described above, the magnetically based angle detection system 1000 and its detection method according to the present invention can detect the absolute angle when the motor stops and / or rotates with high resolution.

Claims

1. An angle detection system utilizing a magnet having a first magnetic track and a second magnetic track, the angle detection system including an absolute angle calculation unit, The absolute angle calculation unit calculates the absolute angle of the position of the magnet using the following digital signals: a first-1 digital signal that detects the magnetic field signal of the first magnetic track and converts it into a digital signal; a first-2 digital signal that detects the magnetic field signal of the first magnetic track and converts it into a digital signal; a second-1 digital signal that detects the magnetic field signal of the second magnetic track and converts it into a digital signal; and a second-2 digital signal that detects the magnetic field signal of the second magnetic track and converts it into a digital signal. The aforementioned digital signal 1-1 and digital signal 1-2 are sinusoidal signals with a 90-degree phase difference between them. The aforementioned digital signal 2-1 and digital signal 2-2 are sinusoidal signals with a 90-degree phase difference between them. The aforementioned absolute angle calculation unit includes: The first difference value calculator calculates the first-1 difference value to the first-4 difference value using the first-1 digital signal, the first-2 digital signal, the second-1 digital signal and the second-2 digital signal. The first-1 difference value to the first-4 difference value includes the phase difference value between the magnetic field signal of the first track and the magnetic field signal of the second track. A data converter that converts the aforementioned difference values ​​from 1-1 to 1-4 into signed difference values ​​from 1-1 to 1-4, respectively, wherein the aforementioned signed difference values ​​from 1-1 to 1-4 are signed values ​​with signs. The offset difference calculator uses multiple difference values ​​from the signed difference values ​​from the first-1 to the first-4 above to calculate the offset difference values ​​from the first-1 to the first-4 above to shift the first-1 to the first-4 above difference values ​​by 45 degrees respectively. The main interval value calculator calculates the main interval value using the signed difference values ​​from the first to the fourth above. The main interval value is the value that divides one 360-degree rotation of the magnet into the first to the fourth main intervals. The sub-interval value calculator calculates a sub-interval value that is a difference value between one of the above-mentioned offset difference values ​​from the first-1 to the first-4, corresponding to the value of the first-1 sub-interval to the first-M sub-interval, for each of the above-mentioned main interval values. The first signal interval value calculator calculates the first signal interval value by dividing the magnetic field signal of the first track into four first signal intervals using the signs of the first-1 digital signal and the first-2 digital signal; and The lower-order interval value calculator calculates the lower-order interval value based on the aforementioned first signal interval value using the aforementioned first-1 digital signal and the aforementioned first-2 digital signal. This lower-order interval value is the value of dividing the aforementioned first signal interval value into K lower-order angle values; and An angle output device outputs absolute angle data of the magnet's position, including the aforementioned main interval value, the aforementioned sub-interval value, the aforementioned first signal interval value, and the aforementioned lower interval value. The aforementioned difference value 1-1 is the sum of the squares of the differences between the aforementioned digital signal 1-1 and the aforementioned digital signal 2-1, and the squares of the differences between the aforementioned digital signal 1-2 and the aforementioned digital signal 2-2. The aforementioned difference values ​​1-2 are the sum of the squares of the difference between the aforementioned digital signal 1-1 and the aforementioned digital signal 2-2, and the squares of the difference between the aforementioned digital signal 1-2 and the inverted signal of the aforementioned digital signal 2-1. The difference values ​​1-3 above are signals that invert the difference values ​​1-1 above. The difference values ​​1-4 above are signals that invert the difference values ​​1-2 above. The aforementioned difference values ​​1-1 through 1-4 each have a phase difference of 90 degrees. The difference values ​​from 1-1 to 1-4 above are each calculated as unsigned values. The signed difference values ​​from 1-1 to 1-4 mentioned above are calculated by subtracting the average of the signed difference values ​​from 1-1 to 1-4 from the signed difference values ​​mentioned above. M is a natural number greater than 2. The above K is a natural number greater than 4.

2. An angle detection system utilizing a magnet having a first magnetic track and a second magnetic track, the angle detection system including an absolute angle calculation unit, The absolute angle calculation unit calculates the absolute angle of the position of the magnet using the following digital signals: a first-1 digital signal that detects the magnetic field signal of the first magnetic track and converts it into a digital signal; a first-2 digital signal that detects the magnetic field signal of the first magnetic track and converts it into a digital signal; a second-1 digital signal that detects the magnetic field signal of the second magnetic track and converts it into a digital signal; and a second-2 digital signal that detects the magnetic field signal of the second magnetic track and converts it into a digital signal. The aforementioned digital signal 1-1 and digital signal 1-2 are sinusoidal signals with a 90-degree phase difference between them. The aforementioned digital signal 2-1 and digital signal 2-2 are sinusoidal signals with a 90-degree phase difference between them. The aforementioned absolute angle calculation unit also includes: The first signal interval value calculator calculates the first signal interval value by dividing the magnetic field signal of the first magnetic track into four first signal intervals using the sign of the first-1 digital signal and the sign of the first-2 digital signal. The lower interval value calculator calculates the lower interval value based on the first signal interval value using the first-1 digital signal and the first-2 digital signal. The lower interval value is the value of dividing the first signal interval value into K lower angle values. The first offset interval value calculator calculates the first signal interval value that has been offset by one interval by shifting the first signal interval value in the first direction by one first signal interval. The second offset interval value calculator calculates the first signal interval value that has been offset by two intervals by shifting the first signal interval value to the first direction by two first signal intervals. The third offset interval value calculator calculates the first signal interval value that has been offset by 3 intervals by shifting the first signal interval value to the first direction by 3 first signal intervals. The first signal interval period calculator uses the above first signal interval value to calculate four first signal intervals to obtain the repeated first signal interval period; The second signal interval value calculator calculates the second signal interval value, which is the value of the second signal interval divided into 4 second signal intervals using the sign of the above-mentioned second-1 digital signal and the sign of the above-mentioned second-2 digital signal; The second difference value calculator sequentially uses one of the following first signal interval values: the un-offset first signal interval value, the first signal interval value offset by one interval, the first signal interval value offset by two intervals, and the first signal interval value offset by three intervals to calculate the second difference value. The second difference value is the difference in position between the first signal interval value and the second signal interval value. When the second difference value reaches a value equivalent to 90 degrees, the used first signal interval value is converted to another first signal interval value among the un-offset first signal interval value, the first signal interval value offset by one interval, the first signal interval value offset by two intervals, and the first signal interval value offset by three intervals, and the second difference value is calculated again. The main interval value calculator calculates the main interval value using the aforementioned second difference value. The second difference value is set at 90-degree intervals, and the main interval value is set from the first main interval to the fourth main interval. The interval from the initial 0 degrees to 90 degrees of the second difference value is set as the first main interval, and the interval from the next 0 degrees to 90 degrees is set as the second main interval. The sub-interval value calculator calculates the sub-interval value by dividing the aforementioned second difference value by the value of the aforementioned first signal interval period. This sub-interval value is the value of P intervals, from the aforementioned first main interval to the aforementioned fourth main interval, respectively corresponding to sub-intervals from 2-1 to 2-P. An angle output device outputs absolute angle data of the magnet's position, including the aforementioned main interval value, the aforementioned sub-interval value, the aforementioned first signal interval value, and the aforementioned lower interval value. The aforementioned first direction refers to either the left or right direction of the register used as the first signal interval value calculator. The above P is a natural number greater than 2. The above K is a natural number greater than 4.

3. An angle detection method, utilizing a magnet having a first magnetic track and a second magnetic track, the angle detection method comprising: The absolute angle calculation steps utilize the following digital signals to calculate the absolute angle of the magnet's position: a first-1 digital signal converted from the magnetic field signal of the first magnetic track, a first-2 digital signal converted from the magnetic field signal of the first magnetic track, a second-1 digital signal converted from the magnetic field signal of the second magnetic track, and a second-2 digital signal converted from the magnetic field signal of the second magnetic track. The aforementioned digital signal 1-1 and digital signal 1-2 are sinusoidal signals with a 90-degree phase difference between them. The aforementioned digital signal 2-1 and digital signal 2-2 are sinusoidal signals with a 90-degree phase difference between them. The above steps for calculating absolute angles include: The first difference value calculation step calculates the first-1 difference value to the first-4 difference value using the first-1 digital signal, the first-2 digital signal, the second-1 digital signal, and the second-2 digital signal. The first-1 difference value to the first-4 difference value includes the phase difference value between the magnetic field signal of the first track and the magnetic field signal of the second track. The data conversion step converts the above-mentioned difference values ​​from 1-1 to 1-4 into signed difference values ​​from 1-1 to 1-4, respectively. The above-mentioned signed difference values ​​from 1-1 to 1-4 are signed values ​​with signs. The offset difference value calculation step uses multiple difference values ​​from the first-1 signed difference value to the first-4 signed difference value to calculate the first-1 offset difference value to the first-4 offset difference value. The first-1 offset difference value to the first-4 offset difference value is obtained by shifting the first-1 difference value to the first-4 difference value by 45 degrees respectively. The main interval value calculation step is to calculate the main interval value using the signed difference value from the first to the fourth signed difference value. The main interval value is the value of dividing the 360-degree rotation of the magnet into the first to the fourth main intervals. The first to the fourth main intervals are four 90-degree intervals. The sub-interval value calculation step is to calculate the sub-interval value, which is the value of the sub-interval from the first-1 to the first-M sub-intervals relative to the first-m sub-interval, based on the first-m sub-interval value. The first signal interval value calculation step involves calculating the first signal interval value by using the sign of the first-1 digital signal and the sign of the first-2 digital signal to divide the magnetic field signal of the first magnetic track into four first signal intervals. The lower-order interval value calculation step involves calculating the lower-order interval value using the first-1 digital signal and the first-2 digital signal, based on the first signal interval value. This lower-order interval value is the value of dividing the first signal interval value into K lower-order angle values. The angle output step outputs the absolute angle data of the magnet's position, including the aforementioned main interval value, the aforementioned sub-interval value, the aforementioned first signal interval value, and the aforementioned lower interval value. The aforementioned difference value 1-1 is the sum of the squares of the differences between the aforementioned digital signal 1-1 and the aforementioned digital signal 2-1, and the squares of the differences between the aforementioned digital signal 1-2 and the aforementioned digital signal 2-2. The aforementioned difference values ​​1-2 are the sum of the squares of the difference between the aforementioned digital signal 1-1 and the aforementioned digital signal 2-2, and the squares of the difference between the aforementioned digital signal 1-2 and the inverted signal of the aforementioned digital signal 2-1. The difference values ​​1-3 above are signals that invert the difference values ​​1-1 above. The difference values ​​1-4 above are signals that invert the difference values ​​1-2 above. The aforementioned difference values ​​1-1 through 1-4 each have a phase difference of 90 degrees. The difference values ​​from 1-1 to 1-4 above are each calculated as unsigned values. The signed difference values ​​from 1-1 to 1-4 mentioned above are calculated by subtracting the average of the signed difference values ​​from 1-1 to 1-4 from the signed difference values ​​mentioned above. M is a natural number greater than 2. The above K is a natural number greater than 4.

4. An angle detection method, utilizing a magnet having a first magnetic track and a second magnetic track, the angle detection method comprising: The absolute angle calculation steps utilize the following digital signals to calculate the absolute angle of the magnet's position: a first-1 digital signal converted from the magnetic field signal of the first magnetic track, a first-2 digital signal converted from the magnetic field signal of the first magnetic track, a second-1 digital signal converted from the magnetic field signal of the second magnetic track, and a second-2 digital signal converted from the magnetic field signal of the second magnetic track. The aforementioned digital signal 1-1 and digital signal 1-2 are sinusoidal signals with a 90-degree phase difference between them. The aforementioned digital signal 2-1 and digital signal 2-2 are sinusoidal signals with a 90-degree phase difference between them. The above absolute angle calculation steps also include: The first signal interval value calculation step involves calculating the first signal interval value by using the sign of the first-1 digital signal and the sign of the first-2 digital signal to divide the magnetic field signal of the first magnetic track into four first signal intervals. The lower interval value calculation step involves calculating the lower interval value based on the first signal interval value using the first-1 digital signal and the first-2 digital signal. The lower interval value is the value of dividing the first signal interval value into K lower angle values. The first offset interval value calculation step involves shifting the aforementioned first signal interval value in the first direction by one first signal interval to calculate the first signal interval value that has been shifted by one interval. The second offset interval value calculation step involves shifting the first signal interval value to the first direction by two first signal intervals to calculate the first signal interval value shifted by two intervals. The third offset interval value calculation step involves shifting the first signal interval value to the first direction by 3 first signal intervals to calculate the first signal interval value shifted by 3 intervals. The first signal interval period calculation step involves using the aforementioned first signal interval value to calculate four first signal intervals to obtain the repeated first signal interval period; The second signal interval value calculation step involves calculating the second signal interval value, which is the value of the second signal interval divided into four second signal intervals using the signs of the above-mentioned second-1 digital signal and the above-mentioned second-2 digital signal. The second difference value calculation step involves sequentially using one of the following interval values: the un-offset first signal interval value, the first signal interval value offset by one interval, the first signal interval value offset by two intervals, and the first signal interval value offset by three intervals. The second difference value is the difference in position between the first signal interval value and the second signal interval value. When the second difference value reaches a value equivalent to 90 degrees, the used first signal interval value is converted to another first signal interval value among the un-offset first signal interval value, the first signal interval value offset by one interval, the first signal interval value offset by two intervals, and the first signal interval value offset by three intervals, and the second difference value is calculated again. The main interval value calculation steps are as follows: the main interval value is calculated using the second difference value mentioned above. The second difference value is set at 90-degree intervals. The main interval value is set from the first main interval to the fourth main interval. The interval from the first 0 degrees to 90 degrees of the second difference value is set as the first main interval. The interval from the next 0 degrees to 90 degrees is set as the second main interval. The sub-interval value calculation step involves dividing the aforementioned second difference value by the value of the aforementioned first signal interval period to calculate the sub-interval value. This sub-interval value is the value of P intervals, from the aforementioned first main interval to the aforementioned fourth main interval, respectively corresponding to sub-intervals from 2-1 to 2-P. The angle output step outputs the absolute angle data of the magnet's position, including the aforementioned main interval value, the aforementioned sub-interval value, the aforementioned first signal interval value, and the aforementioned lower interval value. The first direction mentioned above is either the left or right direction of the register used when calculating the value of the first signal interval mentioned above. The above P is a natural number greater than 2. The above K is a natural number greater than 4.

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