Bidirectional magnetic position sensor having field rotation

The present invention relates to the field of a non-contact magnetic position sensor for the purpose of simultaneously supplying two independent output signals indicating positions in two directions (translational motion and translational motion, translational motion and rotation, rotation and rotation). ..

Sensors that detect position from a magnetic field have many advantages. -No wear due to no mechanical contact with moving parts. -Not affected by dirt. -Manufacturing costs are reduced. -Long service life.

Most non-contact magnetic position sensors detect only one direction (rotational or translational motion), but for example a two-way sensor (two-way sensor) is required to detect the position of the transmission member, or generally rotation. There are more and more uses that seem to be combined with translational movements. In such applications, it is particularly important that the position information in one direction does not depend on the position information in the other direction (independent output signal).

Most existing two-way sensors use permanent magnets associated with somewhat complex magnetic circuits, which are made of ferromagnetic materials that induce and / or concentrate the magnetic flux generated by the permanent magnets. However, ferromagnetic materials are inconvenient for the cost and performance of the sensor.

Thus, in the prior art, the applicant's French Patent No. 2786266, which relates to a two-way position sensor, is known, but the spatial requirements and the surface area of the magnet used make this sensor for long travel ranges. Limits the practical use of. This sensor also has high hysteresis due to the ferromagnetic stator, the measurement of which depends on the variation of the residual induction and must be corrected.

In addition, European Patent No. 80555 describes a linear angular position sensor. This sensor transmits analog signals that are difficult to use due to their non-linearity and low level. Such a sensor requires several separate measurement points to measure relative positions in two directions. In addition, it requires a stator portion that causes hysteresis, and the sensitive element measures the amplitude of the magnetic field, so it is sensitive to geometrical tolerances and temperature.

U.S. Pat. No. 4639667 or WO 9716736 describes a sensor that operates according to the principle of not being able to output linear independent signals that represent positions in two directions.

There are also two-way sensors that simply connect the ends of two independent unidirectional sensors. For example, WO 2008138662 and WO 2008138662 describe two linear sensors, each measuring one direction. Each sensor has a magnet and an element that detects the magnetic field, resulting in high spatial requirements and high manufacturing costs. In addition, these sensors measure the amplitude of the magnetic field and are therefore sensitive to geometric tolerances and temperature.

In the prior art, sensors in US Pat. No. 4,421,923 and US Pat. No. 7,293,480 that detect gears that engage gear levers are also known. The patent presents a solution for detecting position in two directions, but uses a magnet, a gear to detect, and at least as many Hall sensors in space. Therefore, it is necessary to obtain digital detection of gears using a sensor array that distinguishes individual positions. Having multiple sensors means that implementing this solution is expensive and does not provide a means of knowing the intermediate position.

In order to improve the problem related to the position detection by the amplitude measurement described above, there is a position sensor that measures the rotation of the magnetic field, that is, the direction thereof, instead of the amplitude. However, this applies primarily to unidirectional sensors rather than bidirectional sensors.

For example, as described in Applicant's French Patent No. 2898189 and French Patent No. 2909170, the direction of the magnetic field rather than the amplitude is used to detect the relative position between the magnet and the magnetically sensitive probe. The prior art sensors used are known. This directional measurement can be made less sensitive to temperature and mechanical clearance, and magnetic hysteresis does not occur because no ferromagnetic part is used. However, since such a sensor measures only a single magnetic field direction by calculating a single amplitude ratio from the two components of the magnetic field, the position of the movable magnet relative to the magnetically sensitive probe can be determined in only one direction instead of two. You can know. Similarly, in US Pat. No. 6,731,108, US Pat. No. 6,960,974, and WO 2004015375, only the linear movement of a magnet with respect to one or more magnetically sensitive elements utilizing the magnetic field direction. To measure. However, in order to realistically execute a movement range larger than 20 to 25 mm, these sensors require multiple probes to be placed in various parts of the movement range, which increases the sensor cost and increases the probe. It needs to be positioned accurately.

However, in the prior art, a solution that measures the position in two directions and uses the measurement of rotation instead of the amplitude of the magnetic field is also known, but it is limited to a very specific application for controlling a lever (joystick). Thus, US Pat. No. 20070240433 or US Pat. No. 20090062064 has only two components, a simple magnet that is unidirectionally magnetized along its thickness and a magnetic field, and thus a single magnetic field direction (two components). Describes a joystick sensor with a probe that measures the angle formed by the magnet. With this principle, it is not possible to output independent linear signals in two directions. Also, the joystick type system is limited to rotation only and cannot measure translational motion.

Furthermore, the angle detectable by the joystick system is limited to about 30 degrees. Beyond this, if the magnet is placed far away from the probe, it will not be possible to see enough magnetic field to estimate its position. In fact, for practical applications for movement ranges greater than 40 degrees, these sensors require several probes based on different parts of the movement range, increasing sensor costs.

In the prior art, there is also a Melexis application note on the measurement of two axes of rotation (http://www.melexis.com/Sensor_ICs_Hall_effect/Triaxis_Hall_ICs/MLX90333_648.aspx), which presents two joystick structures. The first solution requires a complex and large mechanical system that cannot be easily incorporated in practical use because the center of rotation of the bipolar magnet fuses with the measurement point. The second structure presents a solution in which the center of rotation of the magnet is located behind the magnet (the magnet is between the center of rotation and the sensitive element). In this case, the three components of the magnetic field are used to determine the two rotation angles. The magnet used is an ultra-small diameter cylinder with constant magnetization in amplitude and direction along the thickness. That is, the magnetization of the magnet at any point on the magnet has the same coefficient and is perpendicular to the top and bottom surfaces of the magnet. This very specific structure is only intended to measure two angles over a very short range of motion (about 30 degrees). This is because it is necessary to reduce the diameter of the magnet (theoretically, a punctate magnet with radial magnetization) so that the algorithm used can detect the rotation of the magnet. That is, as soon as the rotation of the small magnet occurs, the magnet moves away from the magnetically sensitive element, and the magnetic induction of the probe in the magnetically sensitive element becomes very small, so that the rotation of the magnet cannot be detected accurately. This kind of system is expensive and difficult to magnetize because it has a very high residual magnetism (usually Br> 1.2T) and requires a very thick (thickness> 10mm) magnet. Large axial thickness (usually> 10 mm) poses a problem with space requirements. Also, in these solutions, the mechanical gap between the flat magnet surface and the measurement point fluctuates with the rotation of the magnet, resulting in reduced linearity and collision between the magnet edge and the probe support. Accompanied by larger voids than required to avoid. Ideal to prevent this is a magnet with a very small diameter, but with the problems mentioned above.

<p> Therefore, the invention presented herein is particularly simple and efficient in solving the problems of the two-way sensor described above (range of movement limitation, rotation-only measurement, high residual magnetism and thick magnets, high spatial requirements and high cost, etc.). Suggest improvements in the way.</p>

<p> Specifically, with a magnetically sensitive probe that measures at least two components of the magnetic field at about the same point as the magnetizing element, preferably using measurements in the direction of the magnetic field rather than amplitude, without limitation of the high or low range of motion. We propose an absolute position sensor in any two directions (translational motion-translational motion, translational motion-rotation, or rotation-rotation) that measures the relative movement between them.</p><p> More specifically, it is a magnetic position sensor in at least two directions, and is arranged at substantially the same point as at least one magnetizing element (1), and each of the components of the magnetic field generated by the magnetizing element (1). It has a probe (6) with at least two magnetic sensitive elements (2) and (3) to measure one of them, and the magnetizing element (1) moves relative to the magnetic sensitive elements (2) and (3). It is possible, the probe (6) can calculate the angle and coefficient from the algebraic combination of the components of the magnetic field, and supplies at least two independent signals representing the position of the moving element along each of the two directions. At least one of the dimensions of the magnetizing element, such that the magnetization vector of the magnetizing element (1) defines the unique position of the probe (6) with respect to the magnetizing element (1). We propose a sensor that is variable with respect to a vector perpendicular to the surface of the magnetizing element placed opposite the probe (6).</p><p> This variation in the magnetization vector can be obtained by varying its direction along at least one of the dimensions. In this case, the direction of the magnetization vector can have several periods over the entire range of movement being measured.</p><p> Further, the variation of the magnetization vector can be obtained by changing one of the dimensions of the magnetization element along at least one of the two directions and changing the direction of the vector perpendicular to the surface. In this case, the dimensions may vary depending on the discontinuous function or the sinusoidal continuous function.</p><p> Further, the variation of the magnetization vector can be obtained by varying the amplitude along at least one of the two directions. In all of these cases, the magnetization vector has at least one alternance in at least one of the two directions.</p><p> In all of these cases, the signal processing circuit can perform at least two arctangent calculations or at least one arctangent calculation and one coefficient calculation. In all of these cases, the signal processing circuit can also apply a correction factor between the two components of the magnetic field and then perform an inverse tangent calculation of the ratio of the two components.</p><p> In the modification of the present invention, the processing circuit is integrated with the magnetically sensitive element as a single element. In the modifications of the present invention, the magnetizing element consists of a permanent magnet and at least one ferromagnetic part. Finally, preferably, the measured magnetic field components fluctuate substantially sinusoidally in each of at least two directions.</p><p> In general, this sensor is a thin rare earth type (SmCo, NdFeB) with a single magnetizing element, preferably a range of motion that is substantially equal to the desired range of motion, with no restrictions on the range of motion other than the dimensions of the magnet. Alternatively, it has a ferrite type permanent magnet.</p><p> The fact that this sensor has a single magnetically sensitive probe that measures the three components of the magnetic field at a single point leads to minimal spatial requirements and low cost. This sensor eliminates fluctuations in the magnetic properties of magnets with temperature and time, making them less susceptible to fluctuations in geometric tolerances and voids, and proposes an extremely strong solution using the amplitude ratio between the components of the magnetic field. can do. Since this sensor does not have a ferromagnetic part fixed to the magnetic sensitive element, it does not have magnetic hysteresis while guaranteeing the simplicity of the structure.</p><p> Finally, the sensor provides very accurate individual position information for each of the two directions. The function of the sensor is defined more precisely below.</p><p> Let M be the point where the magnetic sensitive elements are collected and measure the three components of the magnetic field, and let O'be the center point of the outer surface of the magnetizing element (1) facing the probe (6) in which the magnetic sensitive elements are integrated. Point 0 is used when at least one of the two directions is, in this case, a rotation centered on O. Therefore, the following vector equation can be written.</p><p><maths num="1"><img file="JP5538552B2_D0001.tif" /></maths> vector</p><p><maths num="2"><img file="JP5538552B2_D0002.tif" /></maths>Is constant and depends only on the shape of the magnet, the reference of this vector corresponds to the outer radius of the magnet for tile or spherical magnets and zero for parallelepiped magnets.</p><p> vector</p><p><maths num="3"><img file="JP5538552B2_D0003.tif" /></maths>Is constant and oriented along the thickness of the magnet, i.e.</p><p><maths num="4"><img file="JP5538552B2_D0004.tif" /></maths>So z₀Is usually referred to as the void between the magnetizing element and the point M where the magnetically sensitive elements are collected.</p><p> Therefore,</p><p><maths num="5"><img file="JP5538552B2_D0005.tif" /></maths>Is</p><p><maths num="6"><img file="JP5538552B2_D0006.tif" /></maths>When</p><p><maths num="7"><img file="JP5538552B2_D0007.tif" /></maths>It is defined as a vector representing the position of the magnetizing element with respect to the magnetically sensitive element in two directions of the moving element oriented along. For simplicity, these directions are referred to here as X and Y.</p><p><maths num="8"><img file="JP5538552B2_D0008.tif" /></maths>When</p><p><maths num="9"><img file="JP5538552B2_D0009.tif" /></maths>Corresponds to each relative movement along.</p><p> Therefore, the two directions X and Y may be two translational motions in which X and Y correspond to the length, or x corresponds to the length and y corresponds to the rotation and the translational motion corresponding to the angle. Alternatively, x and y may both be two rotations corresponding to an angle.</p><p> In order to determine the position of the magnetizing element with respect to the magnetically sensitive element in the two directions X and Y of the movable element, it is necessary to determine the coordinates x and y. In general, whether a straight, cylindrical, or spherical magnet, the thickness thereafter is a unit vector perpendicular to the top surface of the magnet.</p><p><maths num="10"><img file="JP5538552B2_D0010.tif" /></maths>Corresponds to the dimension of the magnet oriented along, and the length is the vector in contact with the top surface of the magnet.</p><p><maths num="11"><img file="JP5538552B2_D0011.tif" /></maths>Corresponds to the dimension of the magnet oriented by, the depth touches the top surface of the magnet and is a vector</p><p><maths num="12"><img file="JP5538552B2_D0012.tif" /></maths>Vector perpendicular to</p><p><maths num="13"><img file="JP5538552B2_D0013.tif" /></maths>Corresponds to the dimension of the magnet oriented by. Reference frame used for straight, cylindrical, or spherical magnets</p><p><maths num="14"><img file="JP5538552B2_D0014.tif" /></maths>Are Cartesian, Polar, and Spherical Reference Frames, respectively.</p><p> According to the first embodiment, the sensor comprises a magnetizing element (preferably a permanent magnet) that produces a magnetic field, while (preferably a permanent magnet).</p><p><maths num="15"><img file="JP5538552B2_D0015.tif" /></maths>Normal component (along), on the other hand (along)</p><p><maths num="16"><img file="JP5538552B2_D0016.tif" /></maths>Tangent component (along) and (along)</p><p><maths num="17"><img file="JP5538552B2_D0017.tif" /></maths>The lateral component (along) is measured on its surface and fluctuates periodically (depending on the reference mechanical period called λx and λy), with one or more effective variations along the surface. It can correspond to the entire cycle or a part of the cycle.</p><p> According to the suitable structure, the magnetizing element has a length and depth that are substantially similar to the range of movement used, and a magnetization direction that varies substantially linearly in two directions X and Y with respect to thickness, length, and depth. Has.</p><p> That is, at any point A on the outer surface of the magnetizing element, the magnetization vector</p><p><maths num="18"><img file="JP5538552B2_D0018.tif" /></maths>And normal vector</p><p><maths num="19"><img file="JP5538552B2_D0019.tif" /></maths>The angle between, i.e.</p><p><maths num="20"><img file="JP5538552B2_D0020.tif" /></maths>And the magnetization vector</p><p><maths num="21"><img file="JP5538552B2_D0021.tif" /></maths>And vector</p><p><maths num="22"><img file="JP5538552B2_D0022.tif" /></maths>The angle between, i.e.</p><p><maths num="23"><img file="JP5538552B2_D0023.tif" /></maths>Fluctuates linearly in direction X and is a magnetization vector</p><p><maths num="24"><img file="JP5538552B2_D0024.tif" /></maths>And normal vector</p><p><maths num="25"><img file="JP5538552B2_D0025.tif" /></maths>And the magnetization vector</p><p><maths num="26"><img file="JP5538552B2_D0026.tif" /></maths>And vector</p><p><maths num="27"><img file="JP5538552B2_D0027.tif" /></maths>The angle between them varies linearly in the direction Y.</p><p> In the vicinity of this magnetizing element, this magnetization is a magnetic field</p><p><maths num="28"><img file="JP5538552B2_D0028.tif" /></maths>The tangent (Bx), normal (Bn), and lateral (By) components are substantially sinusoidal over most of the range of motion in directions X and Y.</p><p> Therefore, the measurement points of the magnetic field components Bx, By, and Bz generated by the magnetizing element are M (x, y, z) with length Lx, width Ly, and thickness Lz.₀) Magnets. +/- y_maxIs the maximum range of movement you want to measure in direction Y, y_maxIs less than, equal to, or greater than the width of the magnetizing element.</p><p> +/- x_maxIs the maximum range of movement you want to measure in direction X, x_maxIs less than, equal to, or greater than the width of the magnetizing element. I want to know the positions along X and Y, that is, x and y. z₀Corresponds to the measurement gap between the movable element and the fixed element.</p><p> The magnetic field components By and Bz have the same phase along X, but the component Bx is out of phase by a quarter of the period. In this first embodiment, the magnetization is M (x, y, z₀) Generates a magnetic field so that the magnetic field component can be written as follows.</p><p><maths num="29"><img file="JP5538552B2_D0029.tif" /></maths></p><p><maths num="30"><img file="JP5538552B2_D0030.tif" /></maths></p><p><maths num="31"><img file="JP5538552B2_D0031.tif" /></maths> However, λx and λy are wavelengths at which the magnetic field rotates 360 degrees along X and Y, respectively, and A is other than zero for each sensor, which depends on the void between the surface of the magnetizing element and the magnetically sensitive element and the shape of the magnetizing element. Is a constant of.</p><p> In the case of this first preferred embodiment, the magnetization is O'and perpendicular to the center of the magnet.</p><p><maths num="32"><img file="JP5538552B2_D0032.tif" /></maths>Will be. Magnetization can be rotated 360 degrees along X and Y, for example. That is, the magnetization is rotated 360 degrees over the entire length of the magnetizing element and 360 degrees over the entire width of the magnetizing element, in which case λx = Lx and λy = Ly. Arbitrary point M (x, y, z) on the magnetizing element₀) Is as follows.</p><p><maths num="33"><img file="JP5538552B2_D0033.tif" /></maths></p><p><maths num="34"><img file="JP5538552B2_D0034.tif" /></maths></p><p><maths num="35"><img file="JP5538552B2_D0035.tif" /></maths> Of course, according to the magnetic field generated by the magnetizing element, the wavelength λy can be much larger than the width of the magnetizing element Ly, as in FIGS. 4, 5, and 6, if λy is greater than the width Ly. , Means that the magnetization is rotated less than 360 degrees over the entire width of the magnetization device.</p><p> When the magnetic field components Bx, By, and Bz are measured at any point M in the space surrounding the magnetizing element, the positions of directions X and Y can be determined by applying the following equations to estimate x and y. Can be grasped. Measurements of the three magnetic components can be performed using three magnetically sensitive elements, co-located and integrated into the same package, called probes (6), using components of the type, for example MLX90333 or HAL3625. it can.</p><p> The following calculations can be performed from these three components (Fig. 9).</p><p><maths num="36"><img file="JP5538552B2_D0036.tif" /></maths></p><p><maths num="37"><img file="JP5538552B2_D0037.tif" /></maths> The Bx, By, Bz components of the magnetic field are measured at point M at coordinates x, y, z0, and kx, ky correct the gain factor assigned to the measurement of the magnetic field component to standardize the components. This calculation can be done within a single component with a magnetically sensitive element, or can then be performed by an external element of the probe (microcontroller, microprocessor, ECU, etc.).</p><p> Obtained by applying these equations.</p><p><maths num="38"><img file="JP5538552B2_D0038.tif" /></maths> Therefore,</p><p><maths num="39"><img file="JP5538552B2_D0039.tif" /></maths>Is a linear function of the variable x, and the evaluation of the calculation can determine the position of the value x and, by extension, the position of the point M with respect to the center of the magnetizing element O'in the direction X. Since M is the point where the magnetically sensitive element is arranged, the relative position of the magnetizing element with respect to the magnetically sensitive element can be grasped. Therefore, the relative position along X is independent of temperature and voids, and can be determined with high accuracy (usually less than 1% of the entire movement range). Since the gradient and ordinate coordinates at the origin are programmable because they depend only on the magnet and its magnetization, it can be achieved by programming the probe (6) so that this output is equal to zero at x = 0.</p><p> Similarly, the inverse tangent (ky Bz / By) can be calculated.</p><p><maths num="40"><img file="JP5538552B2_D0040.tif" /></maths> As a result, as described above with respect to the position along X, the relative position of the magnetizing element in the direction Y with respect to the magnetically sensitive element is derived.</p><p> Therefore, by the magnetization and signal processing as described in the first embodiment, the relative position of the magnetizing element in the two directions X and Y with respect to the magnetically sensitive element is determined from the three components of the magnetic field measured at the same point M. Can be done.</p><p> The following post-treatments can also be used with the same magnetization.</p><p><maths num="41"><img file="JP5538552B2_D0041.tif" /></maths> According to a second embodiment, the present invention comprises a magnetizing element (preferably a permanent magnet) that produces a magnetic field, while (preferably a permanent magnet).</p><p><maths num="42"><img file="JP5538552B2_D0042.tif" /></maths>Normal component (along), on the other hand (along)</p><p><maths num="43"><img file="JP5538552B2_D0043.tif" /></maths>Tangent components (along) and (along)</p><p><maths num="44"><img file="JP5538552B2_D0044.tif" /></maths>The lateral component (along) is measured on its surface and fluctuates periodically (depending on the reference mechanical period called λx and λy), with one or more effective variations along the surface. It can correspond to the entire cycle or a part of the cycle.</p><p> According to this second embodiment, the magnetizing element has a magnetization whose magnetization direction varies substantially linearly with respect to its thickness and length along only one of the two directions. That is, at any point A on the magnetization element, the magnetization vector</p><p><maths num="45"><img file="JP5538552B2_D0045.tif" /></maths>And normal vector</p><p><maths num="46"><img file="JP5538552B2_D0046.tif" /></maths>The angle between, i.e.</p><p><maths num="47"><img file="JP5538552B2_D0047.tif" /></maths>, And magnetization vector</p><p><maths num="48"><img file="JP5538552B2_D0048.tif" /></maths>And vector</p><p><maths num="49"><img file="JP5538552B2_D0049.tif" /></maths>The angle between, i.e.</p><p><maths num="50"><img file="JP5538552B2_D0050.tif" /></maths>Fluctuates linearly in direction X, but the magnetization vector</p><p><maths num="51"><img file="JP5538552B2_D0051.tif" /></maths>And vector</p><p><maths num="52"><img file="JP5538552B2_D0052.tif" /></maths>The angle between them is constant in the direction Y.</p><p> Since this second embodiment requires a narrow magnetization element (&lt;30 mm or equivalent angle), in the vicinity of this magnetization element, this magnetization is tangent (Bx), normal (Bn) and lateral to the magnet. The (By) component is substantially sinusoidal in most of the moving range and produces a magnetic field that has the same shape as the component of the first embodiment. Due to the peripheral effect, this narrow magnet allows all magnetizing elements to obtain a magnetic field that fluctuates in direction Y in M without having variable magnetization in the Y direction.</p><p> In this second preferred embodiment, the magnetization is perpendicular, tangent, or otherwise to the center O'of the magnet, so in this case Φ = [0; 2π] and the magnetization is 360 in direction X. It can be rotated degrees, but in the direction Y it rotates less than 180 degrees, for example λx = Lx and λy = 2Ly.</p><p> Arbitrary point M (x, y, z) on the magnetizing element₀) Is as follows.</p><p><maths num="53"><img file="JP5538552B2_D0053.tif" /></maths></p><p><maths num="54"><img file="JP5538552B2_D0054.tif" /></maths></p><p><maths num="55"><img file="JP5538552B2_D0055.tif" /></maths> As in the first preferred embodiment,</p><p><maths num="56"><img file="JP5538552B2_D0056.tif" /></maths>When</p><p><maths num="57"><img file="JP5538552B2_D0057.tif" /></maths>Can be calculated.</p><p> Output of this function</p><p><maths num="58"><img file="JP5538552B2_D0058.tif" /></maths>Varies from 2n over the entire range of movement of length Lx.</p><p> Output of this function</p><p><maths num="59"><img file="JP5538552B2_D0059.tif" /></maths>Fluctuates by n over the entire range of movement of length Ly.</p><p> In this embodiment, the inverse tangent can be calculated to determine the position along X, and once this position is known, then only the value of component By is used to estimate the position along Y. Can be done. However, this post-treatment has the disadvantage of using the ingredients directly, that is, the solution is void z₀Sensitive to fluctuations and temperature, but only individual positions to be determined, such as transmission applications that require knowledge of 6th or 7th gear over a given range and do not need to know the intermediate position. Very suitable when there are only a few.</p><p> According to a third preferred embodiment, the magnet has a constant magnetization direction and a magnetization vector at any point on the magnetizing element.</p><p><maths num="60"><img file="JP5538552B2_D0060.tif" /></maths>But</p><p><maths num="61"><img file="JP5538552B2_D0061.tif" /></maths> 、 </p><p><maths num="62"><img file="JP5538552B2_D0062.tif" /></maths>, Or</p><p><maths num="63"><img file="JP5538552B2_D0063.tif" /></maths>The magnetization is on the same line as, that is, the magnetization is along the thickness, length, or width of the magnetizing element. On the other hand, the magnetizing element has a thickness that varies substantially sinusoidally along the two directions X and Y. This substantially sinusoidal variation of thickness over half a period is combined with uniform magnetization to generate a substantially sinusoidal magnetic field on the magnet component and is represented as in the case of the first embodiment described above. According to this third preferred embodiment, the magnetic field generated by this magnetizing element rotates in directions X and Y by about 180 degrees, for example λx = 2Lx and λy = 2Ly. The treatment of the two components for determining x and y is the same as in the first embodiment.</p><p> According to the fourth embodiment, the magnetizing element has a constant magnetization direction and is a magnetization vector at an arbitrary point on the magnet.</p><p><maths num="64"><img file="JP5538552B2_D0064.tif" /></maths>But</p><p><maths num="65"><img file="JP5538552B2_D0065.tif" /></maths> 、 </p><p><maths num="66"><img file="JP5538552B2_D0066.tif" /></maths>, Or</p><p><maths num="67"><img file="JP5538552B2_D0067.tif" /></maths>The magnetization is on the same line as, that is, the magnetization is along the thickness, length, or width of the magnetizing element. On the other hand, the magnetizing element has a thickness that varies substantially sinusoidally in only one of the two directions X and Y. Since this fourth embodiment requires a thin magnet (&lt;30 mm or an equivalent angle), in the vicinity of this magnetizing element, this magnetization is tangent (Bx), normal (Bn) and lateral to the magnet. The (By) component is substantially sinusoidal in most of the moving range and produces a magnetic field that has the same shape as the component of the first embodiment. Due to the marginal effect, the narrow magnet allows all magnetizing elements to obtain a magnetic field that fluctuates in the direction Y in M without requiring a variable thickness in the Y direction.</p><p> As in the third preferred embodiment, the magnetic field generated by this magnetizing element rotates in directions X and Y by about 180 degrees, for example λx = 2Lx and λy = 2Ly. The component processing for determining the positions x and y is the same as in the first embodiment.</p><p> According to a fifth embodiment, the magnetizing element has a magnetization in which the magnetization direction varies substantially linearly in only one of two directions with respect to thickness and length. That is, at any point A on the magnetization element, the magnetization vector</p><p><maths num="68"><img file="JP5538552B2_D0068.tif" /></maths>And normal vector</p><p><maths num="69"><img file="JP5538552B2_D0069.tif" /></maths>The angle between, i.e.</p><p><maths num="70"><img file="JP5538552B2_D0070.tif" /></maths>, And magnetization vector</p><p><maths num="71"><img file="JP5538552B2_D0071.tif" /></maths>And vector</p><p><maths num="72"><img file="JP5538552B2_D0072.tif" /></maths>The angle between, i.e.</p><p><maths num="73"><img file="JP5538552B2_D0073.tif" /></maths>Fluctuates linearly in direction X, but the magnetization vector</p><p><maths num="74"><img file="JP5538552B2_D0074.tif" /></maths>And vector</p><p><maths num="75"><img file="JP5538552B2_D0075.tif" /></maths>The angle between them is constant in the direction Y.</p><p> Further, unlike the second embodiment, the magnetizing element has a thickness that fluctuates along only one (Y) of the two directions, and fluctuates stepwise according to a discontinuous function. In this case, the following post-processing can be performed using only the magnetic field components Bx and Bz.</p><p><maths num="76"><img file="JP5538552B2_D0076.tif" /></maths>as well as</p><p><maths num="77"><img file="JP5538552B2_D0077.tif" /></maths> Assuming you have a stepped magnet, the angle calculation provides very accurate information about the linear position along X, and the coefficients provide approximate position information in the direction Y. However, this solution may be very effective when the position along Y can be discretized using a probe with only two measurable components, such as the MLX90316. The number of steps the magnet has along Y usually corresponds to the number of positions that can be discretized. This embodiment can be used, for example, to distinguish gears in transmission applications.</p><p> According to the sixth embodiment, the magnetizing element has a magnetization in which the magnetization direction is not limited but preferably constant along the thickness. That is, the magnetization vector</p><p><maths num="78"><img file="JP5538552B2_D0078.tif" /></maths>Is at any point on the magnet</p><p><maths num="79"><img file="JP5538552B2_D0079.tif" /></maths>Is on the same straight line as.</p><p> On the other hand, the amplitude of the magnetization vector varies linearly along one or both of the two directions. That is, at any point A on the magnetization element, the magnetization vector</p><p><maths num="80"><img file="JP5538552B2_D0080.tif" /></maths>Is oriented along the thickness of the magnet, but the amplitude of this vector varies in a sinusoidal manner along one or both of the directions X and Y.</p><p> Therefore, it becomes as follows.</p><p><maths num="81"><img file="JP5538552B2_D0081.tif" /></maths>, A1 and A1 are constants that depend on the magnetizing element.</p><p> According to a seventh embodiment applied when at least one direction is rotation (which is believed to be indicated by Y), the present invention comprises a tiled magnetizing element. According to this embodiment, the magnetizing element has a diameter magnetization in which the magnetization direction varies substantially linearly along the rotation direction Y only with respect to the thickness.</p><p> That is, at any point A on the magnetization element, the magnetization vector</p><p><maths num="82"><img file="JP5538552B2_D0082.tif" /></maths>And normal vector</p><p><maths num="83"><img file="JP5538552B2_D0083.tif" /></maths>The angle between, i.e.</p><p><maths num="84"><img file="JP5538552B2_D0084.tif" /></maths>Variables linearly in the direction of rotation Y, and the magnetization vector</p><p><maths num="85"><img file="JP5538552B2_D0085.tif" /></maths>And vector</p><p><maths num="86"><img file="JP5538552B2_D0086.tif" /></maths>The angle between, i.e.</p><p><maths num="87"><img file="JP5538552B2_D0087.tif" /></maths>Is constant in the direction X, where X is the translational direction of motion.</p><p> The diameter magnetization is the magnetization vector at each point A on the magnetization element M.</p><p><maths num="88"><img file="JP5538552B2_D0088.tif" /></maths>Means that is on the same straight line as shown in FIG.</p><p> Since this embodiment requires a short magnetization element (&lt;30 mm or an equivalent angle), in the vicinity of this magnetization element, this magnetization is tangent (Bx), normal (Bn) and lateral (By) with respect to the magnet. ) The component is substantially sinusoidal in most of the moving range, generating a magnetic field that has the same shape as the component of the first embodiment. Due to the peripheral effect, the short magnetization device allows it to obtain a magnetic field that fluctuates in the direction X in M without having all magnetizing elements have variable magnetization in the X direction.</p><p> According to the preferred embodiment, the magnetization can be perpendicular, tangent, or otherwise to the center O'of the magnet, so in this case Φ = [0; 2π] and the magnetization is about the same as the angle of the magnet tile. Rotate. That is, if there is a 90 degree tilt, the magnetic field generated by this tile will rotate about 90 degrees.</p><p> According to the eighth embodiment, the magnetizing element has a length and a depth substantially adjacent to an effective moving range, and a magnetization in which the magnetization direction varies discontinuously in two directions. Magnetization vector at any point A on the magnetizing element</p><p><maths num="89"><img file="JP5538552B2_D0089.tif" /></maths>And normal vector</p><p><maths num="90"><img file="JP5538552B2_D0090.tif" /></maths>The angle between, i.e.</p><p><maths num="91"><img file="JP5538552B2_D0091.tif" /></maths>Alternates 0 to 180 degrees in direction X or two directions X and Y as shown in FIG.</p><p> In the vicinity of this magnetizing element, this magnetization is a magnetic field in which the tangent (Bx), normal (Bn) and lateral (By) components with respect to the magnet are substantially sinusoidal in most of the range of motion in directions X and Y.</p><p><maths num="92"><img file="JP5538552B2_D0092.tif" /></maths>By generating the above and applying the post-treatment of the same components as in the first embodiment, the position of the magnetizing element with respect to the magnetically sensitive element can be derived in two directions X and Y.</p><p> Of course, these embodiments are not inclusive and other magnetization or magnet geometry is possible. The present invention will be better understood by reading the following description with reference to the drawings.</p>

<figref num="1">It is a figure of the solution of the prior art.</figref><figref num="2">It is a figure which shows various geometric shapes of a magnetizing element and a reference frame associated with it.</figref><figref num="3">It is a figure which shows one Embodiment that a sensor comprises a parallelepiped magnetizing element and a probe.</figref><figref num="4">It is a figure which shows the component Bx of the magnetic field obtained by the magnetization which concerns on one of the embodiments described by this invention.</figref><figref num="5">It is a figure which shows the component Bz of the magnetic field obtained by the magnetization which concerns on one of the embodiments described by this invention.</figref><figref num="6">It is a figure which shows the component By of the magnetic field obtained by the magnetization which concerns on one of the embodiments described by this invention.</figref><figref num="7">It is a figure which shows the change of the component By of the magnetic field along the axis X with respect to some positions y.</figref><figref num="8">It is a figure which shows the processing of the magnetic field for estimating two positions in two directions.</figref><figref num="9a">It is a figure which shows various algorithms of post-processing of the component Bx, By, Bz for determining the position x and y of a moving body along X and Y.</figref><figref num="9b">It is a figure which shows various algorithms of post-processing of the component Bx, By, Bz for determining the position x and y of a moving body along X and Y.</figref><figref num="9c">It is a figure which shows various algorithms of post-processing of the component Bx, By, Bz for determining the position x and y of a moving body along X and Y.</figref><figref num="10">It is a figure which shows the output signal which concerns on one Embodiment of this invention which can determine the position along X regardless of the position along Y.</figref><figref num="11">It is a figure which shows the output signal which concerns on one Embodiment of this invention which can determine the position along direction Y regardless of the position along X.</figref><figref num="12">FIG. 5 is a plan view of a linearly magnetized device having a constant thickness and having sinusoidal magnetization in several directions according to an embodiment of the present invention.</figref><figref num="13">It is a perspective view of a magnetized tile element having a constant thickness and having sinusoidal magnetization in several directions in which X is rotation and Y is translational motion.</figref><figref num="14">It is a figure which shows the thin linear magnetization element which has a constant thickness and continuous sinusoidal magnetization in a direction X, which concerns on one Embodiment of this invention.</figref><figref num="15">It is a figure which shows the circular magnetizing element which the thickness fluctuates in a pseudo-sinusoidal shape along several directions, and is magnetized almost through the thickness.</figref><figref num="16">It is a figure which shows the linear magnetization element which fluctuates in the direction X in a pseudo-sinusoidal shape and is magnetized almost through the thickness.</figref><figref num="17">It is a figure which shows the magnet which the thickness fluctuates discontinuously in a direction Y, and has a sinusoidal magnetization in a direction X.</figref><figref num="18">It is a side view and a plan view of a magnetizing element which has a constant thickness and has magnetization through the thickness, but whose amplitude is sinusoidal in the direction X.</figref><figref num="19">FIG. 5 is a perspective view of a tile magnetizing element having a constant thickness and diameter magnetization in which the direction X is rotation and the direction Y is translational motion.</figref><figref num="20">FIG. 5 is a cross-sectional view and a perspective view of an elliptical magnetizing element having a constant thickness and having an alternating north-south magnetization in directions X and Y.</figref><figref num="21">It is a figure which shows the narrow linear magnetization element which has a constant thickness and continuous sinusoidal magnetization of direction X, and the ferromagnetic part connected to the magnetization element which reduces the peripheral effect.</figref>

Figure 1 shows a prior art solution that can measure two rotation angles. In this case, the three components of the magnetic field are used to determine the two angles of rotation. The magnet used is a cylinder of constant thickness that is magnetized only through its thickness. This very specific structure is only intended to measure two angles with a very small range of motion, as constant magnetization throughout the thickness is not suitable for measuring angles greater than about 30 degrees. ..

Figures 2a, 2b, and 2c show the position of the magnetizing element (1) with respect to the probe (6) in rotation and translational motion (Fig. 2a), two translational motions (Fig. 2b), and two rotations (Fig. 2c), respectively. It is a perspective view, the front view, and the side view of the magnetization element (1) and the probe (6) used in this embodiment for determining (x, y).

In any embodiment of the present invention, the probe 6 stays on the moving surface and moves with respect to the magnetizing element 1 without rotating about an axis perpendicular to the moving surface. Further, in the embodiments of FIGS. 2a, 2b, 2c, 3 to 6, 10 to 14, and 18 to 21, the distance for separating the moving surface of the probe from the upper surface of the magnetizing element 1 is constant.

Therefore, the moving surface of the probe 6 is a part of a cylinder coaxial with the cylindrical upper surface of the magnetizing element 1 in the embodiments of FIGS. 2a, 13, and 19, FIGS. 2b, 3 to 6, 10 to 12, 14, 18 and In the embodiments 20 to 21, it is composed of a flat portion parallel to the flat upper surface of the magnetizing element 1, and in the embodiment of FIG. 2c, it is composed of a part of a sphere concentric with the spherical upper surface of the magnetizing element 1.

On the other hand, in the embodiments of FIGS. 15 and 16 where the probe 6 moves on a moving surface consisting of a plane parallel to the central plane of the magnetizing element 1, the distance between the probe 6 and the non-flat top surface of the magnetizing element 1 is shown in FIG. In the case of the 15th embodiment, it changes in the positive constants as a sine function of the relative positions of the probe 6 and the magnetizing element 1 in the directions X and Y in the case of the embodiment of FIG.

Similar to the embodiment of FIG. 17, where the probe moves on a moving surface consisting of a surface parallel to the fixed surface of the magnetizing element 1, the distance between the probe 6 and the non-flat top surface of the magnetizing element 1 is the probe in direction Y. It changes within a positive constant as a pseudo-sine function of the relative position of 6 and the magnetizing element 1.

O is the center of rotation when the direction is rotational, and O'is the center of the outer surface of the magnetizing element.

<maths num="93"><img file="JP5538552B2_D0093.tif" /></maths>Is zero if the two directions are translational motions, but in other cases

<maths num="94"><img file="JP5538552B2_D0094.tif" /></maths>And R_extIs the outer radius of the magnetizing element. M is the point where the magnetically sensitive element is collected in the probe (6), and A is the normal vector on the outer surface of the magnetizing element (1).

<maths num="95"><img file="JP5538552B2_D0095.tif" /></maths>It is a projection along.

<maths num="96"><img file="JP5538552B2_D0096.tif" /></maths>Is a reference frame used to define the various positioned points O', A, and M. For Figures 2a, 2b, and 2c, the reference frames are, respectively.

<maths num="97"><img file="JP5538552B2_D0097.tif" /></maths>Is the normal vector at the point on the surface,

<maths num="98"><img file="JP5538552B2_D0098.tif" /></maths>Is a cylindrical, Cartesian and spherical reference frame that is a vector tangent to this surface at the same point. Therefore vector

<maths num="99"><img file="JP5538552B2_D0099.tif" /></maths>Is a vector at A

<maths num="100"><img file="JP5538552B2_D0100.tif" /></maths>It is on the same straight line as, and its normal corresponds to the measurement void z0, which is a constant of the sensor. Figures 2a, 2b, and 2c

<maths num="101"><img file="JP5538552B2_D0101.tif" /></maths>Is shown. Therefore, an object of the present invention is a vector.

<maths num="102"><img file="JP5538552B2_D0102.tif" /></maths>The pair (X, Y) is to be determined to determine the position of the magnetizing element (1) with respect to the magnetically sensitive elements (2) and (3) of the probe (6) in the two directions oriented by.

In these Figures 2a, 2b and 2c, the reference frame

<maths num="103"><img file="JP5538552B2_D0103.tif" /></maths>The dimension of the magnetizing element (1) related to is defined for each structure. In the case of Figure 2a, it is a matter of linear length, angular length, and thickness, respectively. In the case of Figure 2b, it is a matter of length, width, and thickness, respectively. In the case of Figure 2c, it is a matter of first angular length, second angular length, and thickness.

In FIG. 3, the sensor is a parallelepiped magnetizing element (1) of length Lx, width Ly, center O (0,0,0) and an element (1) in directions X and Y with respect to the probe (6). With a probe (6) capable of measuring the three components (Bx, By, Bz) of the magnetic field generated by the magnetizing element (1) at M (x, y, z0) to obtain the position (x, y) It is a top view of the embodiment which consists of. The moving range of the magnetizing element (1) along X is (2xmax), the moving range along y is (2ymax), and 2xmax and 2ymax are substantially equivalent to Lx and Ly, respectively.

FIG. 4 shows an arbitrary point M (x, x, obtained by magnetization of the magnetizing element (1), probe (6), and magnetizing element (1) according to one of the embodiments described by the present invention. y, z0) and the component (Bx) of the magnetic field at a given measurement void z0 are shown. In this case, the magnetizing element (1)

<maths num="104"><img file="JP5538552B2_D0104.tif" /></maths>A magnetic field component Bx that fluctuates in a sinusoidal manner in two directions X and Y is generated so as to be.

FIG. 5 shows at any point (x, y) and measurement void z0, which has the same structure as the previous drawing.

<maths num="105"><img file="JP5538552B2_D0105.tif" /></maths>Indicates the magnetic field component (Bz) that can be written as.

FIG. 6 shows at any point (x, y) and measurement void z0, which has the same structure as the previous two drawings.

<maths num="106"><img file="JP5538552B2_D0106.tif" /></maths>Indicates the magnetic field component (Bz) that can be written as.

FIG. 7 shows the change in the direction X of the component By in mm and the magnetic field generated by the magnetizing element (1) according to one embodiment of the present invention with respect to eight positions corresponding to different Ys at a given void z0. Shows the change in Gauss. In this case, xmax = 10, ymax = 4, Bymax = 400, phi = 0, λ4 = 20, λ2 = 4, and A = z0.

FIG. 8 shows a probe (6) capable of measuring the three components of the magnetic field from at least two (2) and (3) of these magnetically sensitive elements generated by the magnetizing element (1) and located at the same point. The processing of the magnetic field B measured by is shown. Once these three components are obtained, the processing circuit (5) can calculate the angles and coefficients from the algebraic combinations between the components in order to determine the position of the magnetizing element along X and Y with respect to the probe. The processing circuit (5) can be integrated within the probe (6) or run externally via a microcontroller or ECU.

Figures 9a, 9b, and 9c show after the components Bx, By, and Bz for determining the position of the magnetizing device with respect to the probe (6) along X and Y, depending on the type of magnetizing device and the selected magnetization. Various algorithms for processing are shown. Figure 9a shows how the three components of the magnetic field are used by calculating the inverse tangent (K1Bx / Bz) and the inverse tangent (K2By / Bz) to determine the positions x and y. Figure 9b shows a method using only two components of the magnetic field by calculating the inverse tangent (K1Bx / Bz) and the coefficient (root (Bx ^ 2 + Bz ^ 2)) to determine the positions x and y. Shown. Figure 9 shows the inverse tangent (root ((K1Bz) ^ 2 + (K2By) ^ 2) / Bx) and inverse tangent (root ((K1Bz) ^ 2 + (K2Bx) ^ 2) to determine positions x and y. ) / By) is calculated to show how to use the three components of the magnetic field.

FIG. 10 shows the determination of the position along X from the magnetic field components Bx and Bz as shown in FIGS. 4 and 5 using the process defined in 9a, regardless of the position along Y. An output signal according to an embodiment of the present invention that can be performed is shown. The output signal is obtained by calculating the inverse tangent of (Kx * Bx / Bz) and provides a linear output signal along X regardless of Y, with a probe (6) in direction X no matter what measurement void z0 is. ), The position of the magnetizing element (1) can be determined.

By the same principle, FIG. 11 shows an output signal that can determine the position along Y regardless of the position along X. The output signal is obtained by calculating the inverse tangent of (Ky * By / Bz) and provides a linear output signal along Y regardless of X, a probe in the second direction Y no matter what the measurement void z0 is. The position of the magnetizing element (1) with respect to (2) can be determined.

Figure 12 shows the vector

<maths num="107"><img file="JP5538552B2_D0107.tif" /></maths>A linear magnetization device of constant thickness, represented by, whose magnetization direction is defined by a combination of movement directions X and Y and has magnetization that varies linearly in several directions in a plane perpendicular to these directions, that is, Z. (1) is shown. In this figure and all of the drawings below, the solid arrow of the magnetizing element (1) is the axis of the reference frame as defined in Figure 2b.

<maths num="108"><img file="JP5538552B2_D0108.tif" /></maths>The dotted circle represents the outgoing magnetization direction, and the circle with a cross represents the incoming magnetization direction. As shown, the field line of the magnetizing element (1) defined in this way is non-collinear and constitutes one of the basic principles of the present invention, phi = pi / 2, but of the magnetizing element. It is possible to generate magnetic field components as shown in Figures 4, 5, or 6 in any dimension.

Figure 13 shows the vector

<maths num="109"><img file="JP5538552B2_D0109.tif" /></maths>A tile magnet of constant thickness, represented by, whose magnetization direction is defined by a combination of movement directions X and Y and has a magnetization that varies linearly in several directions in a plane perpendicular to these directions, i.e. Z. It is a perspective view of 1). As shown, the field line of the magnetizing element (1) defined in this way is non-collinear and constitutes one of the basic principles of the present invention, phi = pi / 2, but of the magnetizing element. It is possible to generate magnetic field components as shown in Figures 4, 5, or 6 in any dimension. In this case, X is the direction of rotation and Y is the direction of translational motion.

FIG. 14 shows an embodiment applied to a linearly magnetizing device (1) having a constant thickness. According to this particular embodiment, the magnetizing element (1) is a vector.

<maths num="110"><img file="JP5538552B2_D0110.tif" /></maths>It has a magnetization in which the magnetization direction linearly fluctuates along the length of the magnetizing element in a plane defined by the moving direction X and perpendicular to the direction Z. As shown, the field lines of the magnetizing element are non-collinear, constitute one of the basic principles of the present invention, and are shown in FIGS. 4, 5, and 6 when the width Ly of the magnetizing element is small. It is possible to generate such a magnetic field component.

FIG. 15 shows a circular magnet (1) whose thickness varies along a radius in a pseudo-sinusoidal shape and is magnetized over almost the entire thickness (direction Z). In this embodiment, a magnetic field can be generated as follows, regardless of the dimension of the magnet. Bx (x, y, z0) = BxMAX * cos (2pi / λp * x + phi) * cos (2pi / λx * y) * A / z0By (x, y, z0) = ByMAX * sin (2pi / λp * x + phi) * sin (2pi / λ * y) * A / z0Bz (x, y, z0) = BzMAX * sin (2pi / λp * x + phi) * cos (2pi / λ * y) * A / z0 However, phi = pi / 2 and λu = xmax and λe = ymax.

The KxBx / Bz or KyBy / Bz inverse tangent calculation performed by (5) provides a linear signal and information about the position of the magnet with respect to the probe along the two axes X and Y.

FIG. 16 shows a magnetizing element (1) having a magnetization in which the magnetization directions are oriented so as to substantially intersect the thickness, but the thickness fluctuates in a pseudo-sinusoidal shape. According to this embodiment, when the width Ly of the magnetizing element (1) is small, the measured components of the magnetic field are as follows. Bx (x, y, z0) = BxMAX * cos (2pi / λp * x + phi) * cos (2pi / λx * y) * A / z0By (x, y, z0} = ByMAX * sin (2pi / λp *) x + phi) * sin (2pi / λ * y) * A / z0Bx (x, y, z0) = BzMax * sin (2pi / λp * x + phi) * cos (2pi / λ * y) * A / z0 However, phi = pi / 2, λh = xmax, and λe = ymax.

The KxBx / Bz or KyBy / Bz calculation performed by (5) provides a linear signal and information about the position of the magnet (1) with respect to the probe (6) along the two axes X and Y.

FIG. 17 shows a magnet (1) whose thickness varies discontinuously along Y and has sinusoidal magnetization along X. In the large void between the magnetizing element and the probe (6), the components of the magnetic field become continuous again, estimating the position of the magnetizing element (1) with respect to the probe (6) in two directions X and Y, so that the inverse tangent KxBx You can calculate / Bz and the coefficient (Bx + Bz).

FIG. 18 is a side view and a plan view of a magnetizing element (1) having a constant thickness and magnetization through the thickness, but whose amplitude is sinusoidal in the direction X. This case is very suitable for the use of anisotropic magnets as the magnetizing element (1). Due to the anisotropy over the entire thickness, it is possible to have magnets with high residual induction. In this case, assuming that there is no change in magnetization in the direction Y, it works in cases where the anisotropic magnet is narrow and benefits from the peripheral effect.

FIG. 19 is a perspective view of a magnetized tile element (1) having a constant thickness and a diameter magnetization in which the direction X is rotation and the direction Y is translational motion. This diameter magnetization corresponds to the magnetization direction, which is variable with respect to the thickness, in this case, the direction X. In this case, assuming that there is no change in magnetization in the direction Y, it works in the case where the magnetization element (1) is narrow and benefits from the peripheral effect can be obtained. In this case, it is also possible to use a magnet that is anisotropic in the radial direction.

FIG. 20 is a cross-sectional view and a perspective view of an elliptical magnetizing element (1) having a constant thickness and an alternating north-south magnetization along the axes X and Y, which is discontinuous along Z. This magnetization gives rise to a specific distance from the magnetic field components Bx, By, Bz to the magnetizing element (1), as shown in FIGS. 4, 5, and 6.

FIG. 21 shows an embodiment of magnetization applied to a linearly magnetizing device (1) having a constant thickness. According to this particular embodiment, the magnetizing element (1) is a vector whose direction varies linearly along the length of the magnet (in a plane defined by the direction of movement X and perpendicular to the direction Z).

<maths num="111"><img file="JP5538552B2_D0111.tif" /></maths>Has magnetization (represented by). A ferromagnetic part (7) is added to the magnetizing element to increase the magnetic field generated by the magnetizing element (1) and reduce the peripheral effect in direction X.

As will be appreciated by those skilled in the art who have read this specification, the present invention moves with respect to the magnetizing element 1 including the case where the movement of the probe has high amplitude in at least one of the two directions of movement. It relates to a magnetic position sensor capable of determining the two-dimensional position of a possible probe 6.

Therefore, the present invention can utilize one or more principles selected from a set of three principles. The first principle can be applied to determine the position of the probe in one or two dimensions of bidirectional movement, with a magnetization that produces at least a substantially sinusoidal magnetic field in each of the one or two dimensions. It comprises providing a magnetizing element to have.

The second principle can be applied to determine the position of the probe in two dimensions for two-dimensional movement only if the amplitude of movement in two dimensions is limited, and thanks to the peripheral effect, the magnetizing element It consists of estimating the position of the probe in this dimension using the measurement of the generated substantially sinusoidal magnetic field.

The third principle can be applied to determine the position of the probe in one-dimensional or two-dimensional movement in two directions, and has a constant magnetization direction in one-dimensional or two-dimensional movement in two directions. It consists of estimating the position of the probe in one or two dimensions using the measurement of the variable intensity magnetic field generated by the device.

This third principle can itself be carried out in two different modes. For example, in the first mode described with reference to FIGS. 15-17, the distance between the probe 6 and the top surface of the magnetizing element 1 varies depending on the position of the probe in one or two dimensions, respectively. It consists of giving a sinusoidal or pseudo-sinusoidal shape to the top surface of the magnetizing element along one or two dimensions, respectively.

For example, the second mode, described with reference to FIG. 18, consists of providing a magnetizing element having a magnetization with varying intensities in one of the two dimensions of movement.