JP4926838B2 - Magnetic detection method and apparatus - Google Patents

Description

  The present invention relates to a magnetic detection method and apparatus, and more particularly, to a magnetic detection method and apparatus for detecting the position of a magnet on a two-dimensional plane.

  Conventionally, it is well known to use a Hall element as a magnetic sensor for detecting the position of a magnet. The Hall element uses a Hall effect generated when a magnetic field is applied, and an output signal (output voltage) appears linearly with respect to the strength of the magnetic field. Therefore, as the magnet approaches the Hall element, the output signal increases. The magnet described here is a commercially available magnet such as ferrite, neodymium, and samarium-cobalt, and can also be an object (such as a coil) that generates a magnetic field.

  It is also well known that precise magnetic detection and magnetic detection over a long distance are possible by calculating a signal obtained from each Hall element using a plurality of Hall elements. FIG. 1 is a schematic diagram for explaining precise magnetic detection using a plurality of Hall elements. A pair of Hall elements (HE) 101 and 102 are mounted on the x-axis. The magnet 103 is movably installed in the x direction at a position separated from the hall elements 101 and 102 in the z direction. As the magnet 103 moves on the x-axis, the magnetic field applied to the Hall elements 101 and 102 changes, and the output signal of each Hall element changes. By calculating those signals, it is possible to detect the position of the magnet on the x-axis.

Specifically, precise magnetic detection can be performed by calculating the output signal of the Hall element as follows. First, the magnet 103 is moved to both ends x _a and x _b of the movable range on the x axis. For each position, divided by the sum of the output signal the difference between the output signal V _x2 of the output signal V _x1 and the Hall element 102 of the Hall element 101. That is, X = (V _x2 −V _x1 ) / (V _x1 + V _x2 ) is obtained. When X is approximated (linear interpolation) as a function of the position x of the magnet 103 from the X values obtained for the two points x _a and x _b on the x-axis, Equation (1) is obtained. This method is a conventionally known magnetic detection method.
X = cx + d (c and d are constants) (1)

  When a magnet moves on a two-dimensional plane instead of on a straight line, a method of arranging a pair of magnetic sensors such as Hall elements on the x-axis and y-axis of the plane is known. For example, see Patent Documents 1 and 2. By performing linear interpolation as described with reference to FIG. 1 for each axis, the position of the magnet on the two-dimensional plane can be detected.

  A magnetic detection method on a two-dimensional plane using a magnetic sensor such as a Hall element has been applied to, for example, CCD and correction lens position detection performed in camera shake correction of a digital camera (Patent Document 1). And 2).

JP 2005-331549 A JP-A-2005-331400

  The magnetic detection method on the two-dimensional plane is known as described above. However, the conventional method has a detection error due to a deviation from the design position (mounting deviation) when the magnetic sensor is mounted. The accuracy is affected.

  The problem of mounting misalignment will be described with reference to FIG. A pair of Hall elements 201 and 202 are arranged on the x-axis. A pair of Hall elements 203 and 204 are arranged on the y-axis. The Hall element 204 is designed to be arranged on the y axis orthogonal to the x axis, but is located on the y ′ axis due to mounting displacement.

  Here, it is assumed that the magnet has moved from the position (A) to the position (B) on the x-axis. When the y-coordinate of the magnet is calculated in the same manner as in Equation (1), the y-axis is shifted to the y′-axis. Therefore, in reality, there is a magnet at the position (b), and y = 0. The output signal from the element 203 is larger than the output signal from the Hall element 204, and the y coordinate when the magnet is at the position (c) is obtained. That is, since the y-axis is shifted to the y′-axis, it is recognized that the magnet is in the position (c) instead of (b). The deviation between (b) and (c) appears as a magnet detection error. Conventionally, there is no method for correcting this detection error, and measures such as suppressing mounting displacement or designing with tolerance are taken.

  However, in order to suppress mounting displacement, a higher-grade and higher-cost mounting device is required. In addition, the measure of allowing the error to design does not solve the problem of magnetic detection error. Therefore, there is a demand for a method for reducing an error when there is a mounting shift in magnetic detection on a two-dimensional plane.

  The present invention has been made in view of such a problem, and an object of the present invention is to detect the position of a magnet on a two-dimensional plane which reduces magnetic detection errors when there is a mounting deviation. The object is to provide a magnetic detection method and apparatus.

The present invention has been made to achieve such an object, and the invention according to claim 1 is directed to a first coordinate axis (1) on which a first and a second pair of magnetic sensors are respectively arranged. A magnetic detection method for detecting the position of a magnet on a plane parallel to a two-dimensional plane determined by a v-axis) and a second coordinate axis (w-axis), wherein the magnet is on a plane parallel to the two-dimensional plane A first detection signal calculating step for calculating a first detection signal from the output signals of the first pair of magnetic sensors at the position (v, w), and the second pair of magnetism A second detection signal calculation step for calculating a second detection signal from the output signal of the sensor, and a first arrangement error of the first pair of magnetic sensors with respect to the first coordinate axis is approximated as a first function. And with respect to the second coordinate axis of the second pair of magnetic sensors. A second placement errors approximated as a second function, the the first and second functions, each of the first detection signal and the second detection signal applied to the first and second arrangement And a position calculating step of calculating the position (v, w) of the magnet by calculating an error .

The invention according to claim 2 is the parameter reading step of reading a parameter from the recording medium according to claim 1, wherein the parameter is calculated from output signals of the first pair of magnetic sensors. 4 is calculated from the inclination a and intercept b obtained by linear interpolation of the detection signal of 3 as a function of the coordinates of the first coordinate axis of the magnet, and the output signal of the second pair of magnetic sensors. Is calculated from the inclination c and intercept d obtained by linear interpolation as a function of the coordinates of the first coordinate axis of the magnet, and the output signal of the first pair of magnetic sensors. A sixth detection calculated from the inclination e and intercept f obtained by linear interpolation of the detection signal as a function of the coordinates of the second coordinate axis of the magnet and the output signal of the second pair of magnetic sensors. Signal before Including a gradient g and an intercept h obtained by linear interpolation as a function of the coordinates of the second coordinate axis of the magnet, and the position calculating step uses V as the first detection signal and W as the second detection signal. And the position (v, w) is v = {(V−f) − (W−h) e / g} / a
w = {(W−d) − (V−b) c / a} / g
It is calculated as follows.

  According to a third aspect of the present invention, in the second aspect, the first to sixth detection signals are proportional to a value obtained by dividing a difference between output signals of a pair of magnetic sensors by a sum of the output signals. It is calculated by multiplying by a constant.

  According to a fourth aspect of the present invention, in the second aspect, the first to sixth detection signals are calculated by multiplying a difference between output signals of a pair of magnetic sensors by a proportional constant. And

The invention according to claim 5 is a two-dimensional plane determined by a first coordinate axis (v-axis) and a second coordinate axis (w-axis) on which the first and second pairs of magnetic sensors are respectively arranged. A magnetic detection device for detecting a position of a magnet on a parallel plane, wherein a first detection is performed from the first and second pairs of magnetic sensors and output signals of the first pair of magnetic sensors. A first detection signal calculating means for calculating a signal; a second detection signal calculating means for calculating a second detection signal from output signals of the second pair of magnetic sensors; A first placement error of the magnetic sensor with respect to the first coordinate axis is approximated as a first function, and a second placement error of the second pair of magnetic sensors with respect to the second coordinate axis is approximated as a second function. approximated, to the first and second functions, each of the first detection By calculating the first and second placement error by applying Nos and the second detection signal, characterized by comprising a position calculating means for calculating the position of the magnet (v, w) .

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the parameter reading means for reading out a parameter from the recording medium, wherein the parameter is calculated from output signals of the first pair of magnetic sensors. 4 is calculated from the inclination a and intercept b obtained by linear interpolation of the detection signal of 3 as a function of the coordinates of the first coordinate axis of the magnet, and the output signal of the second pair of magnetic sensors. Is calculated from the inclination c and intercept d obtained by linear interpolation as a function of the coordinates of the first coordinate axis of the magnet, and the output signal of the first pair of magnetic sensors. A sixth detection calculated from the inclination e and intercept f obtained by linear interpolation of the detection signal as a function of the coordinates of the second coordinate axis of the magnet and the output signal of the second pair of magnetic sensors. Signal to the magnetic field Including a slope g and an intercept h obtained by linear interpolation as a function of the coordinates of the second coordinate axis, and the position calculating means uses the first detection signal as V and the second detection signal. Is W, and the position (v, w) is v = {(V−f) − (W−h) e / g} / a
w = {(W−d) − (V−b) c / a} / g
It is calculated as follows.

  According to a seventh aspect of the present invention, in the sixth aspect, the first to sixth detection signals are proportional to a value obtained by dividing a difference between output signals of a pair of magnetic sensors by a sum of the output signals. It is calculated by multiplying by a constant.

  According to an eighth aspect of the present invention, in the sixth aspect, the first to sixth detection signals are calculated by multiplying a difference between output signals of a pair of magnetic sensors by a proportional constant. And

The invention according to claim 9 detects the position (v, w) of the magnet on a plane parallel to a two-dimensional plane determined by the first coordinate axis (v-axis) and the second coordinate axis (w-axis). Output signals of the first pair of magnetic sensors, which are arranged on the first and second coordinate axes, respectively, and to which the output signals of the first and second pairs of magnetic sensors are input. A first detection signal calculation step for calculating a first detection signal from the second detection signal calculation step, a second detection signal calculation step for calculating a second detection signal from output signals of the second pair of magnetic sensors, The first arrangement error of the first pair of magnetic sensors with respect to the first coordinate axis is approximated as a first function, and the second arrangement error of the second pair of magnetic sensors with respect to the second coordinate axis is approximated. approximated as a second function, the first and second Seki To, by calculating the first and second placement error respectively by applying the first detection signal and the second detection signal, a position calculation step of calculating the position of the magnet (v, w) Is a program for executing

  According to the present invention, in detecting the position of a magnet on a plane parallel to a two-dimensional plane determined by two axes each having a pair of magnetic sensors, the arrangement of the pair of magnetic sensors with respect to one axis There was a mounting deviation of the magnetic sensor by calculating the position of the magnet by approximating the error as a function using a detection signal calculated from the output signal of a pair of magnetic sensors arranged on the other axis. In this case, a magnetic detection method and apparatus for reducing the maximum error in magnetic detection can be provided.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 3 shows a magnetic detection device and a magnet for carrying out the magnetic detection method according to the present invention. The magnetic detection device 300 includes a pair of Hall elements 301 and 302 disposed on the x-axis, a pair of Hall elements 303 and 304 disposed on the y-axis, and a pair of Hall elements 301 and 302. An operational amplifier 305 that amplifies the difference between the output signals, an operational amplifier 306 that amplifies the difference between the output signals from the pair of Hall elements 303 and 304, and a sample hold (S / H) that samples and holds the output signals from the operational amplifiers 305 and 306 A circuit 307, a calculation unit 308 that calculates the position of the magnet based on the output signals of the Hall elements 301 to 304 via the sample hold circuit 307, and a memory 309 connected to the calculation unit 308 are provided. The arithmetic unit 308 reads a program for causing the arithmetic unit 308 to execute the magnetic detection method according to the present invention and various recorded parameters from the memory 309, and executes each step of the magnetic detection method according to the present invention. Can function as. The Hall elements 301 to 304 are arranged on the x-axis or the y-axis by design, but there is a mounting deviation as shown in the figure. The magnet 310 is installed in the vertical direction away from the plane on which the Hall elements 301 to 304 are arranged.

  As the calculation unit 308, a simple microcomputer capable of performing AD processing on the output signal of the Hall element and performing calculation processing can be used. Alternatively, a semiconductor component such as a transistor may be assembled as a discrete component. In order to make the size the smallest, an arithmetic IC or the like made into an IC is suitable.

  The operational amplifiers 305 and 306 and the sample hold circuit 307 are exemplary configurations, and any configuration may be used as long as the output signals of the Hall elements 301 to 304 can be used for calculation of the magnet position in the calculation unit 308.

  FIG. 4 is a flowchart for explaining the magnetic detection method according to the present invention. The magnetic detection method according to the present invention uses the output signal of the magnetic sensor arranged on the other axis in addition to the output signal of the magnetic sensor arranged on the other axis when calculating the coordinates of one axis. The initial setting and the detection position calculation based on the initial setting. First, the initial setting will be described.

In step 401, the detection signal calculated from the output signals of the pair of Hall elements 301 and 302 on the x-axis is linearly interpolated as a function of the x-coordinate of the magnet as expressed by Equation (1), and the inclination is obtained. Find a and intercept b.
X = ax + b (1)
Specifically, the drive unit (not shown) attached to the magnet or manually moves the magnet to both ends of the movable range in the x direction, and calculates the detection signal X for each point. The detection signal X can be obtained by dividing the difference between the output signals of a pair of magnetic sensors arranged on the x-axis by the sum of the output signals, as described in the related art. The detection signal may be the difference between the output signals of the pair of magnetic sensors, but the temperature characteristics of the magnet and the magnetic sensor can be canceled by dividing the detection signal by the sum of the output signals. Whether the output signal difference is divided by the sum of the output signals or the output signal difference is used, a value obtained by multiplying an arbitrary proportionality constant can be used as the detection signal. If the detection signal X obtained for each point at both ends of the movable range is linearly interpolated, the slope a and the intercept b can be obtained. The linear approximation may be performed using not only two points at both ends of the movable range but also three or more points. In any case, the slope a and the intercept b may be obtained.

In step 402, the detection signal calculated from the output signals of the pair of Hall elements 303 and 304 on the y-axis is linearly interpolated as a function of the x-coordinate of the magnet as expressed by Equation (2), and the inclination is obtained. Find c and intercept d.
Y ′ = cx + d (2)

In step 403, the detection signal calculated from the output signals of the pair of Hall elements 301 and 302 on the x-axis is linearly interpolated as a function of the y-coordinate of the magnet as expressed by Equation (3), and the inclination is obtained. e and intercept f are obtained.
X ′ = ey + f (3)

In step 404, the detection signal calculated from the output signals of the pair of Hall elements 303 and 304 on the y-axis is linearly interpolated as a function of the y-coordinate of the magnet as expressed by Equation (4), and the inclination is obtained. Find g and intercept h.
Y = gy + h (4)

  Steps 402 to 404 can be executed in the same manner as in step 401, but the detection signal calculation method needs to be unified in steps 401 to 404. The order in which these steps 401 to 404 are performed is arbitrary. Note that once these steps 401 to 404 are performed, the calculated parameters can be stored in a recording medium such as a memory or a hard disk. That is, it is not necessary to carry out the position calculation step described next in time, and when the position calculation step is performed, the required parameters a to h may be read from the memory or the like.

Using the parameters obtained in this way, in step 405, the magnet detection position can be calculated by mathematical formulas (5) and (6) to perform magnetic detection.
x = {(X−f) − (Y−h) e / g} / a (5)
y = {(Yd)-(Xb) c / a} / g (6)

Here, the derivation of the equations (5) and (6) will be described.
Derivation of Equations (5) and (6) The detected position (x, y) of the magnet according to the prior art using Equation (1) and Equation (4) is an error from the normal position (<x>, <y>). Is included. If the x coordinate error is x ′ and the y coordinate error is y ′,
x = <x> + x ′ (7)
y = <y> + y ′ (8)
It can be expressed as. Here, an error component included in the detection signal X is X ′, and an error component included in the detection signal Y is Y ′.
X ′ = ax ′ + b (9)
Y ′ = gy ′ + h (10)
far. Then, from Equations (1) and (9), Equation (7)
<X> = xx ′ = (XX ′) / a (11)
And transformed from Equations (2) and (10) to Equation (8)
<Y> = y−y ′ = (Y−Y ′) / g (12)
Can be transformed. Assuming that X ′ is represented by Equation (3) above and Y ′ is represented by Equation (2) above, substituting Equations (3) and (2) into Equations (11) and (12) respectively,
<X> = (X− (ey + f)) / a (13)
<Y> = (Y− (cx + d)) / g (14)
It becomes. Substituting Equation (4) into Equation (13) and Equation (1) into Equation (14), <x> = {(X−f) − (Y−h) e / g} / a
<Y> = {(Yd)-(Xb) c / a} / g
Get.

  In other words, the magnetic detection method according to the present invention approximates the error x ′ of the x coordinate as a function of the detection signal Y of the other axis, and subtracts the error x ′ from the detection position x obtained by Equation (1), thereby The detection error is reduced.

Example 1
FIG. 5 shows a two-dimensional plane defined by the x axis on which the pair of hall elements 501 and 502 is arranged and the y axis on which the pair of hall elements 503 and 504 are arranged. The Hall elements 501 to 504 have a mounting misalignment, the Hall elements 501 and 502 are shifted by +0.1 mm and −0.1 mm in the y direction, respectively, and the Hall elements 503 and 504 are +0.1 mm and respectively in the x direction. -0.1 mm offset. The distance between the Hall elements 501 and 502 and the distance between the Hall elements 503 and 504 were both 3.1 mm. The midpoint between the Hall elements mounted on each axis was used as the origin. Magnets each having a length and width of 4.7 mm and a height of 2.0 mm were placed 2.5 mm apart from the two-dimensional plane in the vertical direction. The movable range of the magnet is 0.5 mm in each of the x direction and the y direction. The magnetizing direction of the magnet is the z direction, and each of the N and S poles is magnetized with one pole.

  FIG. 6A shows the position (normal position) of the detected magnet, and FIG. 6B shows the detected position according to the prior art (formula (1)) and the present invention for each position. The error from the normal position of the detection position by the method is shown. Table 1 is a table showing the data of FIG.

  As can be seen from FIG. 6B and Table 1, the magnetic detection error is greatly reduced by the magnetic detection method according to the present invention. For example, the normal position No. Although the magnetic detection error may be deteriorated by the present invention, such as the y coordinate of 2, the error is reliably reduced by the present invention at a position where the magnetic detection error according to the prior art is large. Specifically, the maximum error in magnetic detection according to the prior art is 29.23 μm for both the x-axis and the y-axis, whereas in the present invention, it is 2.08 μm for both the x-axis and the y-axis, and the difference is clear. It is.

Example 2
In the above description and Example 1, the case where the Hall element has a mounting deviation has been considered. However, even when the Hall element is arranged at the design position and there is no mounting displacement, when the magnet is attached to the magnetic detection device as shown in FIG. 3, the magnet is in a direction along the plane where the Hall element is arranged. When it is installed by rotating from the design position, it is equivalent to the Hall element mounting displacement with respect to the magnet, and the magnetic detection method according to the present invention can be applied. The term “mounting misalignment” includes other cases equivalent to the misalignment of the magnetic sensor, such as rotation of a magnet.

  Suppose that the magnet is rotated from the design position and the following mounting displacement occurs equivalently for the Hall element. Conditions other than the mounting deviation are the same as in the first embodiment.

  FIG. 7 shows, for each position, an error from the detection position according to the conventional technique (formula (1)) and the normal position of the detection position according to the method of the present invention. Table 3 is a table showing the data of FIG.

  The maximum error in position detection according to the prior art is 31.55 μm for both the x-axis and the y-axis, whereas in the present invention, it is 2.64 μm for both the x-axis and the y-axis, and the maximum error is reduced by the present invention. ing.

  As described above, the magnetism detection method according to the present invention is a magnet position (x on a plane parallel to a two-dimensional plane defined by two axes x-axis and y-axis on which a pair of magnetic sensors are arranged. , Y), the error included in the coordinates of one axis (for example, the x coordinate) is calculated from the output signals of a pair of magnetic sensors arranged on the other axis (for example, the y axis). By calculating the position (x, y) by approximating it as a function using the detection signal, it is possible to reduce the maximum error in magnetic detection due to mounting deviation of the magnetic sensor.

  Although the Hall sensor has been described as an example of the magnetic sensor so far, the output signal of the magnetic sensor is converted into a voltage even if various magnetoresistive effect (MR) elements, magnetic impedance elements, amorphous wires, etc. are used. It should be noted that the magnetic detection method according to the present invention can be applied by performing necessary signal processing.

  In addition, as shown in FIG. 2, the two axes on the plane are generally composed of the x axis and the y axis which are orthogonal to each other, but the first coordinate axis (v axis) and the second axis which are not orthogonal A coordinate axis (w axis) may be used. For example, even if the v-axis is not orthogonal to the w-axis, it can be converted to an axis orthogonal to the v-axis by applying an axis rotation matrix to the v-axis, so correction can be made using the same equation. It is.

It is a schematic diagram for demonstrating the conventional magnetic detection using a some Hall element. It is a figure for demonstrating the problem of mounting gap. It is a figure which shows the magnetic detection apparatus for enforcing the magnetic detection method which concerns on this invention. It is a flowchart which shows the procedure of the magnetic detection method which concerns on this invention. FIG. 3 is a diagram illustrating an arrangement of Hall elements according to the first embodiment. (A) is a figure which shows the position of the magnet which performed the detection in Example 1, (b) is a figure which shows a detection result. It is a figure which shows the detection result of Example 2.

Explanation of symbols

101, 102 Hall element 103 Magnet 201, 202, 203, 204 Hall element 301, 302, 303, 304 Hall element (corresponding to magnetic sensor)
305, 306 operational amplifier 307 sample hold circuit 308 arithmetic unit 309 memory (corresponding to recording medium)
310 Magnet 501, 502, 503, 504 Hall element (corresponding to magnetic sensor)

Claims (9)

The position of the magnet on a plane parallel to a two-dimensional plane determined by the first coordinate axis (v-axis) and the second coordinate axis (w-axis) on which the first and second pairs of magnetic sensors are respectively arranged. A magnetic detection method for detecting when the magnet is at a position (v, w) on a plane parallel to the two-dimensional plane,
A first detection signal calculating step of calculating a first detection signal from output signals of the first pair of magnetic sensors;
A second detection signal calculating step of calculating a second detection signal from output signals of the second pair of magnetic sensors;
A first arrangement error of the first pair of magnetic sensors with respect to the first coordinate axis is approximated as a first function, and a second arrangement of the second pair of magnetic sensors with respect to the second coordinate axis is approximated. It approximates the error as the second function, the first and second functions, calculating the first and second placement error respectively by applying the first detection signal and the second detection signal And a position calculating step of calculating the position (v, w) of the magnet. A parameter reading step of reading a parameter from a recording medium, wherein the parameter is:
An inclination a and an intercept b obtained by linearly interpolating a third detection signal calculated from output signals of the first pair of magnetic sensors as a function of the coordinates of the first coordinate axis of the magnet;
An inclination c and an intercept d obtained by linearly interpolating a fourth detection signal calculated from the output signals of the second pair of magnetic sensors as a function of the coordinates of the first coordinate axis of the magnet;
An inclination e and an intercept f obtained by linearly interpolating a fifth detection signal calculated from the output signals of the first pair of magnetic sensors as a function of the coordinates of the second coordinate axis of the magnet;
A gradient g and an intercept h obtained by linearly interpolating a sixth detection signal calculated from the output signals of the second pair of magnetic sensors as a function of the coordinates of the second coordinate axis of the magnet. ,
In the position calculating step, the first detection signal is V, the second detection signal is W, and the position (v, w) is v = {(V−f) − (W−h) e / g. } / A
w = {(W−d) − (V−b) c / a} / g
The magnetic detection method according to claim 1, wherein the magnetic detection method is calculated as:   3. The first to sixth detection signals are calculated by multiplying a value obtained by dividing a difference between output signals of a pair of magnetic sensors by a sum of the output signals by a proportional constant. The magnetic detection method described in 1.   3. The magnetic detection method according to claim 2, wherein the first to sixth detection signals are calculated by multiplying a difference between output signals of a pair of magnetic sensors by a proportional constant. Detects the position of a magnet on a plane parallel to a two-dimensional plane determined by a first coordinate axis (v-axis) and a second coordinate axis (w-axis) on which a first and second pair of magnetic sensors are respectively arranged. A magnetic detection device that
The first and second pair of magnetic sensors;
First detection signal calculating means for calculating a first detection signal from output signals of the first pair of magnetic sensors;
Second detection signal calculating means for calculating a second detection signal from output signals of the second pair of magnetic sensors;
A first arrangement error of the first pair of magnetic sensors with respect to the first coordinate axis is approximated as a first function, and a second arrangement of the second pair of magnetic sensors with respect to the second coordinate axis is approximated. by approximating the error as the second function, the first and second functions, calculating the first and second placement error respectively by applying the first detection signal and the second detection signal And a position calculating means for calculating the position (v, w) of the magnet. Parameter reading means for reading a parameter from a recording medium, wherein the parameter is
An inclination a and an intercept b obtained by linearly interpolating a third detection signal calculated from output signals of the first pair of magnetic sensors as a function of the coordinates of the first coordinate axis of the magnet;
An inclination c and an intercept d obtained by linearly interpolating a fourth detection signal calculated from the output signals of the second pair of magnetic sensors as a function of the coordinates of the first coordinate axis of the magnet;
An inclination e and an intercept f obtained by linearly interpolating a fifth detection signal calculated from the output signals of the first pair of magnetic sensors as a function of the coordinates of the second coordinate axis of the magnet;
A gradient g obtained by linearly interpolating a sixth detection signal calculated from the output signals of the second pair of magnetic sensors as a function of the coordinates of the second coordinate axis of the magnet and an intercept h. With things,
The position calculating means sets the position (v, w) to v = {(V−f) − (W−h) e / g, where V is the first detection signal and W is the second detection signal. } / A
w = {(W−d) − (V−b) c / a} / g
The magnetic detection device according to claim 5, wherein the magnetic detection device is calculated as:   7. The first to sixth detection signals are calculated by multiplying a value obtained by dividing a difference between output signals of a pair of magnetic sensors by a sum of the output signals by a proportional constant. The magnetic detection apparatus described in 1.   The magnetic detection device according to claim 6, wherein the first to sixth detection signals are calculated by multiplying a difference between output signals of the pair of magnetic sensors by a proportionality constant. The first and second coordinate axes for detecting the position (v, w) of the magnet on a plane parallel to a two-dimensional plane defined by the first coordinate axis (v-axis) and the second coordinate axis (w-axis) Each of the computers to which the output signals of the first and second pairs of magnetic sensors are input,
A first detection signal calculating step of calculating a first detection signal from output signals of the first pair of magnetic sensors;
A second detection signal calculating step of calculating a second detection signal from output signals of the second pair of magnetic sensors;
A first arrangement error of the first pair of magnetic sensors with respect to the first coordinate axis is approximated as a first function, and a second arrangement of the second pair of magnetic sensors with respect to the second coordinate axis is approximated. by approximating the error as the second function, the first and second functions, calculating the first and second placement error respectively by applying the first detection signal and the second detection signal And a position calculating step for calculating a position (v, w) of the magnet.

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