TWI761072B - Magnetic Linear Position Sensor - Google Patents

Abstract

A magnetic linear position sensor is used to detect the position of a magnet that reciprocates along a linear stroke, wherein a magnetic angle type induction element is arranged on one side of the linear stroke to sense the magnetic field of the magnet and output a sinusoidal signal and A cosine signal, and one of the processing units digitizes the sine signal and the cosine signal into a sine signal value and a cosine signal value, and then performs atan2 (subtracting the sine signal value of a first preset value/subtraction the cosine signal value from a second preset value) is calculated to obtain a curvature value; the processing unit inputs the curvature value into a mathematical model that fits a characteristic curve of the magnetic angle-type sensing element to obtain the A relative distance between the magnetic angle sensing element and the magnet.

Description

Magnetic Linear Position Sensor

The present invention relates to a position sensor, in particular to a magnetic linear position sensor.

Referring to FIG. 1 , one way to obtain the detection distance of a magnetic angle sensing element S (such as AMR, Hall, TMR....) is to make the magnetic angle sensing element S sense the magnet M moving along a linear stroke P1. The magnetic field generates a sine wave signal and a cosine wave signal related to a moving distance of the magnet M and outputs it to a signal processor 10. The signal processor 10 digitizes the sine wave signal and the cosine wave signal as shown in the figure The digitized sine wave signal sin formed by the complex sine signal value Usin shown in Figure 1 and the digitized cosine wave signal cos formed by the complex cosine signal value Ucos shown in Figure 1, and the sine signal values Usin and these The cosine signal value Ucos is subjected to the second derivative (atan2) operation of the arc tangent function (ARCTAN), namely atan2(Usin/Ucos), to obtain complex curvature values, and these curvature values form a curvature curve C1 as shown in Figure 1 , the curvature value of each point on an effective line segment L1 in the curvature curve C1 corresponds to a detection distance, and because the curvature value of the effective line segment L1 only ranges from 0.2 to 1.2, it represents an effective magnetic angle sensing element S. The detection distance is not long. For example, as shown in Figure 1, it is only 6mm. Therefore, if the length to be detected is 6 times that of 6mm, at least 6 magnetic angle sensing elements S need to be connected in parallel for detection at the same time.

Therefore, the purpose of the present invention is to provide a magnetic linear position sensor, which can increase the detection distance of the magnetic angle-type sensing element therein, thereby reducing the number of magnetic angle-type sensing elements used.

及一曲率值範圍建構以擬合該磁性角度型感應元件的一特性曲線，其中i等於1,2,3…n，y _i是該相對距離，xi是該曲率值，β ₀~β _m是該磁性角度型感應元件的係數，該曲率值範圍的最小值和最大值是該特性曲線兩端的曲率值。 Therefore, the present invention is a magnetic linear position sensor for detecting the position of a magnet that reciprocates along a linear stroke, and includes a magnetic angle sensing element and a processing unit; the magnetic angle sensing element is arranged on the linear stroke One side of the magnet is used to sense the magnetic field of the magnet and output a sine signal and a cosine signal; the processing unit is electrically connected to the magnetic angle sensing element to receive the sine signal and the cosine signal, and combine the sine signal and the cosine signal The signal is digitized into a sine signal value and a cosine signal value, and the second derivative of the arctangent function is performed on the sine signal value minus a first predetermined value and the cosine signal value minus a second preset value operation, namely atan2 (subtract the sine signal value of the first preset value/subtract the cosine signal value of the second preset value) to obtain a curvature value; the processing unit inputs the curvature value into an and A mathematical model related to the characteristics of the magnetic angle sensing element to obtain a relative distance between the magnetic angle sensing element and the magnet; the mathematical model is composed of a polynomial equation

and a curvature value range is constructed to fit a characteristic curve of the magnetic angle sensing element, where i is equal to 1, 2, 3...n, _yi is the relative distance, xi is the curvature value, and β ₀ ~β _m are The coefficient of the magnetic angle type induction element, the minimum value and the maximum value of the curvature value range are the curvature values at both ends of the characteristic curve.

的m值以及β ₀~β _m的值，且該訊號處理裝置將該多項式方程式及該曲率值範圍寫入該處理單元中做為該特性曲線的該數學模型。 In some embodiments of the present invention, the mathematical model is established during a calibration procedure of the magnetic linear position sensor, in which the magnet moves along the linear stroke, and a signal processing device causes the processing unit At a sampling frequency, the magnetic angle sensing element is required to return the sine signal and the cosine signal currently generated until the magnet completes the linear travel; the processing unit digitizes the sine signal and the cosine signal and outputs it to the signal processing device, according to the length of the linear stroke and the sampling frequency, to obtain the position of each sampling point of the magnet in the linear stroke and the digitized sine signal value and the cosine signal value Correspondingly, the signal processing device subtracts a first predetermined value from the sine signal values, and subtracts a second predetermined value from the cosine signal values, and the signal processing device subtracts the first predetermined value from the The sine signal values of the value and the cosine signal values minus the second preset value are subjected to the second derivative (atan2) operation of the arctangent function, namely atan2 (subtract the sine signal value of the first preset value /subtract the cosine signal value of the second preset value) to obtain a corresponding complex curvature value, the curvature values constitute a curvature curve, and the signal processing device uses an effective line segment in the curvature curve as a The characteristic curve of the magnetic angle sensing element determines an effective detection distance and a corresponding curvature value range of the magnetic angle sensing element, and determines the polynomial equation through curve fitting and linear regression analysis

and the signal processing device writes the _polynomial equation and the _curvature value range into the processing unit as the mathematical model of the characteristic curve.

In some implementation aspects of the present invention, the first preset value is one of the sum of the maximum value and the minimum value among the sine signal values; the second preset value is one of the cosine signal values Either the maximum value or the minimum value.

In some embodiments of the present invention, m is 6.

In some embodiments of the present invention, the magnetic angle sensing element has two magnetoresistive bridges with a difference of 45°, wherein one magnetoresistive bridge induces the magnetic field of the magnet and generates a sine wave signal, and the other magnetoresistive bridge induces a sine wave signal. The resistive bridge senses the magnetic field of the magnet and generates a cosine wave signal with a phase difference of 45° from the sine wave signal.

In some implementation aspects of the present invention, the processing unit determines that the curvature value is within the curvature value range, and then inputs the curvature value into the mathematical model.

The effect of the present invention lies in: fitting the characteristic curve of the magnetic angle sensing element by the mathematical model of the processing unit, the processing unit only needs to digitally transmit the sine signal and the cosine signal from the magnetic angle sensing element After transformation, atan2 is performed on the sine signal value minus the first preset value and the cosine signal value minus the second preset value (minus the sine signal value of the first preset value/subtract the first preset value After a curvature value is obtained by calculating the cosine signal value of the two preset values, the curvature value is input into the mathematical model, and a simple one-variable m-th degree polynomial equation can be used to quickly obtain a relationship between the magnetic angle type induction element and the magnet. relative distance; and the characteristic curve fitted by the mathematical model determines an effective detection distance of the magnetic angle sensing element and a corresponding curvature value range, and in the calibration procedure, the magnetic angle sensing element is The sine signal values and the cosine signals obtained by the element induction are properly shifted and then the second derivative (atan2) of the arc tangent function (ARCTAN) is calculated, which can increase the effective detection distance and reduce the magnetic angle induction. The number of components used increases the detection distance of the magnetic linear position sensor.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are designated by the same reference numerals.

及一曲率值範圍建構以擬合該磁性角度型感應元件21的一特性曲線，其中i=1,2,3…n，y _i代表該磁性角度型感應元件21與該磁鐵M的一相對距離，xi代表一曲率值，β ₀~β _m代表該磁性角度型感應元件21的係數，該曲率值範圍的最小值和最大值是該特性曲線兩端的曲率值。 Referring to FIG. 2 , it is an embodiment of the magnetic linear position sensor of the present invention, which is used to detect the position of a magnet M that reciprocates along a linear stroke P2 . For example, the magnet M is set in a cylinder 1 . piston, and the linear stroke P2 is the piston stroke of the piston reciprocating in the cylinder 1; the magnetic linear position sensor 2 of this embodiment mainly includes a magnetic angle sensing element 21 and a processing unit 22, such as a microprocessor controller or a microcontroller (MCU). The magnetic angle sensing element 21 is arranged on one side of the linear stroke P2, such as the outer wall of the cylinder 1, to sense the magnetic field of the magnet M and output an analogous sine signal and a cosine signal; the processing unit 22 and the The magnetic angle sensing element 21 is electrically connected to receive the sine signal and the cosine signal, and the processing unit 22 stores a mathematical model related to the characteristics of the magnetic angle sensing element 21, and the mathematical model is composed of a polynomial equation

and a curvature value range is constructed to fit a characteristic curve of the magnetic angle sensing element 21, wherein i=1, 2, 3...n, y _i represents a relative distance between the magnetic angle sensing element 21 and the magnet M , xi represents a curvature value, β ₀ ~β _m represent the coefficients of the magnetic angle sensing element 21 , and the minimum and maximum values of the curvature range are the curvature values at both ends of the characteristic curve.

Specifically, the mathematical model is established in a calibration procedure of the magnetic linear position sensor 2. Since the characteristics of the magnetic angle-type sensing element 21 in each magnetic linear position sensor 2 are different, the Before the magnetic linear position sensor 2 leaves the factory, the magnetic linear position sensor 2 needs to be calibrated to find the mathematical model that conforms to the characteristics of the magnetic angle sensing element 21 ; and as shown in FIG. 3 , the magnetic angle sensing element 21 There are two magnetoresistive bridges (Bridges) 211 and 212 with a difference of 45° (ie, an angle of 45°) in the interior (eg AMR, Hall, TMR....); in the calibration procedure, as shown in Fig. 2, the magnet M moves from the end of the linear stroke P2 away from the magnetic angle sensing element 21 toward the magnetic angle sensing element 21 , and then moves away from the magnetic angle sensing element 21 to the magnetic angle sensing element 21 after passing through the magnetic angle sensing element 21 . At the other end of the linear stroke P2, during this process, the two magnetoresistive bridges 211 and 212 will continue to induce the magnetic field of the magnet M to generate a sine wave signal SIN and a cosine wave signal COS with a phase difference of 45°.

At the same time, a signal processing device 3, such as but not limited to a personal computer, causes the processing unit 22 to request the magnetic angle sensing element 21 to return the currently generated sinusoidal signal at a sampling frequency (eg, 10 times/second) (ie the The value of a certain point of the sine wave signal SIN, the analog voltage value) and the cosine signal (that is, the value of a certain point of the cosine wave signal COS, the analog voltage value), until the magnet M completes the linear stroke P2, thereby, The magnetic angle sensing element 21 returns 10 sine signals and 10 cosine signals per second to the processing unit 22 , and the processing unit 22 digitizes the received sine signals and the cosine signals and outputs them to The signal processing device 3 . The digitized values of the sine signal values Usin and the cosine signal values Ucos can be compared with the values indicated by the vertical axis on the left side of FIG. 4 .

Therefore, the signal processing device 3 can know and digitize the position and digitization of each sampling point of the magnet M in the linear stroke P2 according to a moving distance of the magnet M (ie the length of the linear stroke P2 ) and the sampling frequency The corresponding relationship between the sine signal values Usin and the cosine signal values Ucos, such as the digitized sine wave signal sin composed of the digitized sine signal values Usin shown in FIG. A digitized cosine wave signal cos composed of the digitized cosine signal values Ucos.

Then, the signal processing device 3 subtracts a first preset value from the sinusoidal signal values Usin to become Usin', as shown in FIG. 5 , which is equivalent to shifting the digitized sinusoidal signal sin downward (offset) the first predetermined value. A preset value becomes a shifted digitized sine wave signal sin', and the signal processing device 3 subtracts a second preset value from the cosine signal values Ucos to become Ucos', as shown in FIG. 5, equivalent to The digitized cosine wave signal cos is shifted downward by the second preset value to become a shifted digitized cosine wave signal cos'; and in this embodiment, the first preset value is the sinusoids One of the two of the sum of the maximum value and the minimum value in the signal value Usin, but not limited thereto; the second default value is one of the two of the sum of the maximum value and the minimum value in the cosine signal values Ucos , but not limited to this.

Next, the signal processing device 3 compares the sine signal values Usin' (ie, the digitized sine wave signal sin' after the translation) minus the first preset value and the cosine signals minus the second preset value The value Ucos' (that is, the digitized cosine wave signal cos' after translation) is subjected to the second derivative (atan2) operation of the arc tangent function (ARCTAN), that is, atan2(Usin'/Ucos'), and the corresponding complex curvature value is obtained, the The equal curvature values can be compared to the values indicated by the vertical axis on the right side of FIG. 6 , and these curvature values constitute a curvature curve C2 as shown in FIG. 6 , and an effective line segment L2 of the curvature curve C2 represents the magnetic angle sensing element 21 and determine an effective detection distance of the magnetic angle sensing element 21 and the corresponding curvature value range. For example, when the curvature value is -1, it can be known from the effective line segment L2 (the characteristic curve) The distance value is -2mm, compared to FIG. 2, it can represent that the magnet M is located on the left side of the magnetic angle type induction element 21 and is 2mm away from the magnetic angle type induction element 21; Similarly, when the curvature value is 2, it can be known that the distance value is 2.6mm, which means that the magnet M is located on the right side of the magnetic angle type induction element 21 and is about 2.6mm away from the magnetic angle type induction element 21; and as shown in Figure 6 , in this embodiment, since the curvature value range can reach -π~π, the corresponding effective detection distance can be increased to 14mm. It can be seen that in this embodiment, through the above-mentioned magnetic angle sensing element 21 After the signal value obtained by induction is shifted, the second derivative (atan2) of the arc tangent function (ARCTAN) is calculated, which can increase the detection distance (14mm) of the magnetic angle sensing element 21 to that of the conventional technology (6mm). Therefore, assuming that the length to be detected is 6 times of 6mm, only three magnetic angle sensing elements 21 need to be connected in parallel for detection at the same time, thereby reducing the number of magnetic angle sensing elements 21 used.

的m值以及β ₀~β _m的值。 Then, the signal processing device 3 uses the effective line segment L2 (ie, the effective detection distance and the corresponding curvature value range) as the characteristic curve of the magnetic angle sensing element 21 and determines the magnetic angle sensing element 21 the effective detection distance and the corresponding curvature value range, and the signal processing device 3 determines the polynomial equation by curve fitting and linear regression analysis according to the effective detection distance and the curvature value range

The m value of , and the value of β ₀ ~β _m .

，例如採用多項式擬合(Polynomial Fitting)，以一元m次多項式回歸方程式

來擬合該置換後有效線段L2’，並以如下所示的矩陣解多項式回歸方程式：

Specifically, as shown in FIG. 7(A) , it is assumed that the effective line segment L2 corresponds to 100 positions (that is, the distance values between 100 magnets M and the magnetic angle-type sensing element 21 , that is, the effective detection distance). In this embodiment, the signal processing device 3 will first replace the data of the X-axis and the Y-axis of the effective line segment L2, so that the X-axis changes to show these The curvature value and the Y-axis show the corresponding equidistant value, so that the effective line segment L2 becomes the post-replacement effective line segment L2', as shown in FIG. 7(B). Then, the signal processing device 3 determines the most suitable polynomial equation for the permuted effective line segment L2'

, for example, using polynomial fitting (Polynomial Fitting), a univariate m-degree polynomial regression equation

to fit the permuted effective line segment L2' and solve the polynomial regression equation with the matrix shown below:

where i=1,2,3...n, y ₁ ~y _n represent the 100 distance values, x ₁ ~x _n represent the 100 curvature values, β ₀ ~β _m are coefficients, and since each of the magnetic angles The characteristics of the magnetic angle-type induction element 21 are different, so the coefficients β ₀ ~β _m are also different, so through the above matrix operation, the values of the coefficients β ₀ ~β _m of the magnetic angle type induction element 21 can be found, and Determines the polynomial equation to be used to fit the permuted effective line segment L2'. For example, in this embodiment, the polyfit instruction provided by METLAB can be used to find out the optimal parameters of the above-mentioned one-variable m-th degree polynomial equation and the equation that best matches the effective line segment L2' after replacement.

For example, use the polyfit command to substitute the 100 known curvature values (x ₁ ~x _n ) and the corresponding 100 distance values (y ₁ ~y _n ) into 1 yuan 1 ~1 yuan respectively Among the 8 polynomial equations of the 8th degree, the respective optimal coefficients of these 8 polynomial equations and their fitting results with the effective line segment L2' after replacement will be obtained, and the univariate 6th degree polynomial will be found from these 8 polynomial equations. When the result of the equation fitting the effective line segment L2' after replacement is the best, the signal processing device 3 uses the unary 6th degree polynomial equation with the best fitting result, for example, the equation is y = 2.4431x ⁶ - 8.2418x ⁵ + 15.967x ⁴ - 10.349x ³ + 7.6091x ² + 1.567x + 1.0009, and the univariate 6th degree polynomial equation is used as the mathematical model; y represents the distance between the magnet M and the magnetic angle sensing element 21, and x represents the Curvature value. Then, the signal processing device 3 writes the unary sixth-order polynomial equation and the curvature value range into the processing unit 22 as the mathematical model, and the calibration procedure is completed.

Therefore, when the magnetic linear position sensor 2 is actually applied to the cylinder 1 shown in FIG. 2 , the processing unit 22 receives the analogous sine signal and the cosine signal from the magnetic angle sensing element 21 . , the processing unit 22 digitizes the sine signal and the cosine signal into a sine signal value and a cosine signal value, and subtracts the first preset value from the sine signal value and subtracts the first predetermined value from the cosine signal value. After two preset values, the second derivative (atan2) of the arc tangent function (ARCTAN) is performed on the sine signal value minus the first preset value and the cosine signal value minus the second preset value, That is, atan2 (subtract the sine signal value of the first preset value/subtract the cosine signal value of the second preset value) to obtain a curvature value; then, the processing unit 22 determines whether the curvature value is in When the curvature value is within the range, the curvature value is substituted into the mathematical model, and a distance value can be obtained by the univariate sixth-order polynomial equation, and the distance value represents the distance between the magnetic angle sensing element 21 and the magnet M. A relative distance; then, the processing unit 22 can directly output the distance value for back-end application, or convert the distance value into a corresponding analog signal, such as an analog voltage (such as a voltage value in 1~5V) or The analog current (such as a current value of 4~20mA) is output to the back-end application.

To sum up, the above-mentioned embodiment uses the mathematical model in the processing unit to fit the characteristic curve of the magnetic angle sensing element 21 , and the processing unit only needs to transmit the sinusoidal signal from the magnetic angle sensing element 21 After digitizing with the cosine signal, atan2 is performed on the sine signal value minus the first preset value and the cosine signal value minus the second preset value (the sine signal value minus the first preset value) /Subtract the cosine signal value of the second default value) operation, after obtaining a corresponding curvature value, input the curvature value into the mathematical model for calculating distance, and then quickly obtain through a simple one-variable m-th degree polynomial equation A relative distance between the magnetic angle sensing element 21 and the magnet M; and the characteristic curve fitted by the mathematical model determines an effective detection distance of the magnetic angle sensing element 21 and a corresponding curvature value range , and in the calibration procedure of this embodiment, the sine signal values and the cosine signals obtained by the induction of the magnetic angle sensing element 21 are appropriately shifted and then the second derivative of the arc tangent function (ARCTAN) is performed on them ( atan2) operation can increase the effective detection distance, thereby reducing the number of magnetic angle sensing elements 21 used and making the detection distance of the magnetic linear position sensor 2 longer.

However, the above are only examples of the present invention, and should not limit the scope of the present invention. Any simple equivalent changes and modifications made according to the scope of the application for patent of the present invention and the content of the patent specification are still within the scope of the present invention. within the scope of the invention patent.

1: Cylinder 2: Magnetic Linear Position Sensor 21: Magnetic angle sensing element 211, 212: Magnetoresistive bridge 22: Processing unit 3: Signal processing device M: Magnet (Piston) P2: Linear stroke SIN: Sine wave signal COS: cosine wave signal sin: digitized sine wave signal cos: digitized cosine wave signal sin': digitized sine wave signal after translation cos': digitized cosine wave signal after translation C2: Curvature Curve L2: valid line segment L2': Effective line segment after replacement

Other features and effects of the present invention will be clearly shown in the embodiments with reference to the drawings, wherein: FIG. 1 illustrates a method for obtaining the detection distance of the magnetic angle sensing element in the prior art; FIG. 2 illustrates the elements included in an embodiment of the magnetic linear position sensor of the present invention and an application example thereof; 3 is a schematic diagram of a detailed circuit included in the magnetic angle sensing element of the present embodiment; 4 is a schematic diagram of waveforms of the digitized sine wave signal sin and the digitized cosine wave signal cos after being digitized by the processing unit of the present embodiment; 5 illustrates that the digitized sine wave signal sin and the digitized cosine wave signal cos of FIG. 4 are shifted downward by a first preset value and a second preset value, respectively; FIG. 6 illustrates the operation of the second derivative (atan2) of the arc tangent function (ARCTAN) on the sine wave signal sin' and the cosine wave signal cos' shown in FIG. 5 to obtain corresponding complex curvature values, which constitute a curvature curve C2; and Fig. 7 illustrates that the X-axis data and the Y-axis data of the effective line segment L2 of the curvature curve C2 shown in Fig. 6 are replaced to become the post-replacement effective line segment L2'.

1: Cylinder

2: Magnetic Linear Position Sensor

21: Magnetic angle sensing element

22: Processing unit

3: Signal processing device

M: Magnet (Piston)

P2: Linear stroke

Claims (7)

A magnetic linear position sensor is used to detect the position of a magnet that reciprocates along a linear stroke, and includes: a magnetic angle type induction element arranged on one side of the linear stroke to sense the magnetic field of the magnet and output a sine signal and a cosine signal; and a processing unit electrically connected with the magnetic angle-type sensing element to receive the sine signal and the cosine signal, and digitize the sine signal and the cosine signal into a sine signal value and a cosine signal value, and the second derivative operation of the arc tangent function is performed on the sine signal value minus a first preset value and the cosine signal value minus a second preset value, namely atan2 (minus the first preset value). Set the sine signal value of the value/subtract the cosine signal value of the second default value) to obtain a curvature value; the processing unit inputs the curvature value into one of the parameters related to the characteristics of the magnetic angle type inductive element. Mathematical model to obtain a relative distance between the magnetic angle sensing element and the magnet; the mathematical model is composed of a polynomial equation

and a curvature value range is constructed to fit a characteristic curve of the magnetic angle sensing element, where i=1, 2, 3...n, _yi represents the relative distance, xi represents the curvature value, and β ₀ ~β _m are The coefficient of the magnetic angle type induction element, the minimum value and the maximum value of the curvature value range are the curvature values at both ends of the characteristic curve. The magnetic linear position sensor of claim 1, wherein the mathematical model is established in a calibration procedure of the magnetic linear position sensor, in which the magnet moves along the linear stroke, a signal processing device Make the processing unit request the magnetic angle-type induction element to return the sine signal and the cosine signal currently generated at a sampling frequency until the magnet completes the linear travel; the processing unit digitizes the sine signal and the cosine signal The signal processing device obtains the position of each sampling point of the magnet in the linear travel and the digitized sinusoidal signal values and the The corresponding relationship of cosine signal values, the signal processing device subtracts a first predetermined value from the sine signal values, and subtracts a second predetermined value from the cosine signal values, the signal processing device subtracts the The sine signal values of the first preset value and the cosine signal values minus the second preset value are subjected to the second derivative (atan2) operation of the arc tangent function, that is, atan2 (subtracting the first preset value) the sine signal value/subtract the cosine signal value of the second preset value) to obtain a corresponding complex curvature value, the curvature values constitute a curvature curve, and the signal processing device uses one of the curvature curves The effective line segment is used as the characteristic curve of the magnetic angle sensing element, and an effective detection distance of the magnetic angle sensing element and the corresponding curvature value range are determined according to the characteristic curve, and the curve fitting and linear Regression analysis determines the polynomial equation

and the signal processing device writes the _polynomial equation and the _curvature value range into the processing unit as the mathematical model of the characteristic curve. The magnetic linear position sensor as claimed in claim 2, wherein the first predetermined value is one of a maximum value and a minimum value among the sinusoidal signal values; the second predetermined value is the cosine signal values One of the sum of the maximum value and the minimum value in the signal value. The magnetic linear position sensor of any one of claims 1 to 3, wherein m is six. The magnetic linear position sensor as claimed in any one of claims 1 to 3, wherein the magnetic angle-type sensing element has two magnetoresistive bridges that differ by 45°, wherein one magnetoresistive bridge induces the magnetic field of the magnet and A sine wave signal is generated, wherein another magnetoresistive bridge induces the magnetic field of the magnet and generates a cosine wave signal with a phase difference of 45° from the sine wave signal. The magnetic linear position sensor according to any one of claims 1 to 3, wherein the curvature value ranges from -π to π. The magnetic linear position sensor according to any one of claims 1 to 3, wherein the processing unit determines that the curvature value is within the curvature value range, and then inputs the curvature value into the mathematical model.

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