Magnetic sensor that uses multiple gradiometers for angle detection

Abstract

A magnetic sensor arrangement that has the following features: a magnetic sensor (220) for determining an angular position of a rotatable object (205), wherein the rotatable object (205) is designed to rotate about the center of a rotation axis, and wherein the magnetic sensor (220) comprises a first gradiometer (1, 2) aligned on a first axis and a second gradiometer (3, 4) aligned on a second axis, wherein the first gradiometer (1,2) comprises a first detection element (1) and a second detection element (2), wherein the second gradiometer (3, 4) comprises a third detection element (3) and a fourth detection element (4), wherein the first gradiometer (1, 2) has a first gradiometer center on the first axis and wherein the second gradiometer (3, 4) has a second gradiometer center on the second axis, where the first axis and the second axis are each perpendicular to the axis of rotation, wherein the first gradiometer center is offset from the center of the axis of rotation and the second gradiometer center is offset from the center of the axis of rotation, wherein the first axis and the second axis intersect at a gradiometer interface that is offset from the first gradiometer center or the second gradiometer center, wherein the gradiometer interface is located between the first sensing element (1) and the second sensing element (2) and between the third sensing element (3) and the fourth sensing element (4), and where the first axis and the second axis are not collinear, not orthogonal, and not parallel to each other, the magnetic sensor (220) is intended for: Detect, via the first gradiometer (1, 2) and the second gradiometer (3, 4), a set of magnetic field components of a magnetic field generated by a magnet, where the set of magnetic field components is perpendicular to the axis of rotation; wherein the magnet is designed to rotate together with the rotatable object (205); and Determine, based on the detection of the set of magnetic field components, the angular position of the rotatable object (205).

Description

background

[0001] A magnetic sensor is capable of detecting components of a magnetic field applied to it, such as the magnitude in one or more specific, predefined directions, and / or similar characteristics. The magnetic field generated by a magnet can depend on the magnetization of the magnet, its shape, its environment, and / or other factors. The magnetic sensor can be used to detect, for example, the movement, position, angle of rotation, and / or similar properties of the magnet, which can be attached to an object in a variety of applications, such as mechanical, industrial, and consumer applications.

[0002] US 2015 / 0022192A1 discloses a discrete magnetic angle sensor device. US 2015 / 0137796A1 discloses magnetic field sensors. Brief description

[0003] One object of the present invention is to provide an improved magnetic sensor arrangement, an improved magnetic sensor and a corresponding method.

[0004] This problem is solved by the attached claims.

[0005] The scope of protection is defined by the attached claims.

[0006] According to some implementations, a magnetic sensor arrangement can include a magnetic sensor for determining the angular position of a rotatable object, wherein the rotatable object is configured to rotate about a center of the axis of rotation, and wherein the magnetic sensor comprises a first gradiometer with a first set of sensing elements aligned on a first axis, and a second gradiometer with a second set of sensing elements aligned on a second axis, wherein the first gradiometer has a first gradiometer center on the first axis, and wherein the second gradiometer has a second gradiometer center on the second axis, wherein the first axis lies in a first plane and the second axis lies in a second plane, the first plane and the second plane being perpendicular to the axis of rotation.wherein the first gradiometer center is offset from the center of the axis of rotation and the second gradiometer center is offset from the center of the axis of rotation, such that the magnetic sensor can detect, via the first and second gradiometers, a set of magnetic field components of a magnetic field generated by a magnet, wherein the set of magnetic field components is perpendicular to the axis of rotation; wherein the magnet is configured to rotate together with the rotatable object; and to determine the angular position of the rotatable object based on the detection of the set of magnetic field components.

[0007] According to some implementations, a magnetic sensor may comprise a first gradiometer having a first set of sensing elements aligned along a first axis, the first gradiometer having a first gradiometer center on the first axis; a second gradiometer having a second set of sensing elements aligned along a second axis, the second gradiometer having a second gradiometer center on the second axis, the first axis lying in a first plane and the second axis lying in a second plane, the first plane and the second plane being perpendicular to the center of a rotation axis of a rotatable object, the first set of sensing elements and the second set of sensing elements being configured to detect a set of magnetic field components perpendicular to the center of the rotation axis;and a digital signal processor that can obtain the set of magnetic field components via the first gradiometer and the second gradiometer, wherein the set of magnetic field components is measured from a magnetic field generated by a magnet designed to rotate together with the rotatable object; and to determine an angular position of the rotatable object based on obtaining the set of components of the magnetic field.

[0008] An exemplary method may involve positioning a magnet at one end of a rotatable object, wherein the rotatable object is configured to rotate about the center of a rotational axis;and the positioning of a magnetic sensor, which is to be positioned at an axial distance from the magnet and offset from the center of the axis of rotation, wherein the magnetic sensor comprises a first gradiometer with a first set of sensing elements aligned on a first axis and a second gradiometer with a second set of sensing elements aligned on a second axis, wherein the first gradiometer has a first gradiometer center on the first axis and wherein the second gradiometer has a second gradiometer center on the second axis, wherein the first axis lies in a first plane and the second axis lies in a second plane, wherein the first plane and the second plane are each perpendicular to the axis of rotation, wherein the first gradiometer center is offset from the center of the axis of rotation and the second gradiometer center is offset from the center of the axis of rotation. Brief description of the drawings Fig. 1A and Fig. Figure 1B shows diagrams of an exemplary implementation described herein. Fig. Figure 2 is a diagram of an exemplary environment in which magnetic arrangements, devices and systems and / or methods described herein may be implemented. Fig. Figure 3 is a diagram of an exemplary magnet located in the exemplary environment of Fig. It may contain 2. Fig. 4 is a diagram of an exemplary gradiometer, which is located in the magnetic sensor of Fig. It may contain 3. Fig. Figures 5-9 are diagrams relating to exemplary implementations of a magnetic sensor arrangement described herein. Fig. Figure 10 is a flowchart of an exemplary process related to the configuration of a magnetic sensor arrangement as described herein. Detailed description

[0009] The following detailed description of example implementations refers to the accompanying drawings. The same reference symbols in different drawings may identify the same or similar elements.

[0010] In some cases, magnetic sensors are used to determine the angle of a rotatable object. In exemplary embodiments, the magnetic sensors can be used to determine an absolute angle of rotation from an instantaneous measurement. For example, the magnetic sensors can be used to determine an angle between 0 and 360 degrees. The object can be a rotatable shaft incorporating a magnet designed to rotate with the shaft. For example, the magnet can be fixed to the rotatable shaft, connected to the rotatable shaft, formed as part of the rotatable shaft, and / or the like. The magnetic sensors can be offset from the rotatable shaft at its ends. In such cases, however, the magnetic sensors can be affected by disturbances in the magnetic field (e.g., due to interference superimposed on the magnetic field).Accordingly, the output from the magnetic sensor may be faulty and display the wrong angular position of the rotatable shaft.

[0011] In some cases, the magnetic sensor may include one or more gradiometers to determine the absolute angular position (or angle of rotation) of the rotatable shaft. The gradiometers may employ a set of sensing elements and indicate the difference between the magnetic field components detected by each element at different respective positions. Therefore, the one or more gradiometers can suppress disturbances in the magnetic field by detecting the magnetic field from multiple positions (i.e., the respective positions of each sensing element). However, the closer the sensing elements are to each other, the greater the probability that a disturbance in the magnetic field will be detected by each of the gradiometer's sensing elements.Therefore, a signal from the gradiometer can be relatively small due to the low inhomogeneity of any disturbance (which may be due to the positioning of the magnetic angle sensor relative to the center of the rotating shaft's axis of rotation). On the other hand, increasing the size of the semiconductor substrate (e.g., a silicon chip) of the magnetic sensor, which comprises the one or more gradiometers, in order to increase the distance between the sensing elements of the one or more gradiometers, can be costly. For example, increasing the size of the magnetic sensor (e.g., greater than 5 mm) may require more material and / or a greater amount of available space to place the magnetic sensor in a system or machine that uses it (e.g., a vehicle, an application, a manufacturing machine, and / or the like).

[0012] Some implementations described herein create a magnetic sensor array and / or a magnetic sensor that increases the probability that a disturbance in the magnetic field will not be detected by every sensing element. To increase this probability, the exemplary magnetic sensor array and magnetic sensor may include multiple gradiometers, each with sensing elements that are relatively far apart (e.g., greater than 2 mm) and positioned relative to the center of a rotation axis of a rotatable object. Furthermore, some implementations described herein may maintain a relatively small size (e.g., with a length, width, and / or radius of less than 5 mm) for the magnetic sensor to detect the angular position.In some implementations described herein, multiple gradiometers can be configured within a magnetic sensor such that the distance between sensing elements is maximized and the multiple gradiometers are arranged on axes in planes perpendicular to the center of the axis of rotation. In some implementations, the magnetic sensor (or a substrate and / or gradiometer of the magnetic sensor) can be offset from the center of the axis of rotation, such that one or more centers of the multiple gradiometers are offset from the center of the axis of rotation.

[0013] Accordingly, some of the exemplary implementations described herein can increase the accuracy of determining the angular position of a rotatable object. Therefore, system errors, failures, and / or accidents caused by the use of legacy techniques can be avoided by using one or more of the exemplary implementations of a magnetic sensor array and / or magnetic sensor described herein.

[0014] Fig. 1A and Fig. Figure 1B shows diagrams of an exemplary implementation 100 described herein. The exemplary implementation 100 includes a magnetic sensor for determining the angular position of a rotatable object. As described in Fig. As shown in Figure 1A, the exemplary implementation 100 comprises the rotatable object (e.g., a rotatable shaft), a magnet configured to rotate with the rotatable object, and the magnetic sensor with multiple sensing elements 1 to 4 used to determine the angular position of the rotatable object. As shown in Figure 1A, the exemplary implementation 100 comprises the rotatable object (e.g., a rotatable shaft), a magnet configured to rotate with the rotatable object, and the magnetic sensor with multiple sensing elements 1 to 4 used to determine the angular position of the rotatable object. Fig. Figure 1B shows a top view of the magnetic sensor, illustrating an exemplary layout of a first gradiometer having sensing elements 1 and 2, and a second gradiometer having sensing elements 3 and 4.

[0015] As it is in Fig. As shown in Figure 1A, the magnetic sensor is positioned away from the end of the magnet, creating an air gap (corresponding, for example, to an axial distance) between the magnet and the magnetic sensor (or a semiconductor substrate of the magnetic sensor). The size of this exemplary air gap can depend on the size and / or design of the magnetic sensor. For example, the air gap size can be based on the distance between the sensing elements of the first gradiometer and the second gradiometer. Additionally or alternatively, the air gap size can depend on the configuration of the magnet (e.g., its size, magnetization, and / or the like). In some implementations, the air gap size is less than 10 mm.

[0016] As further explained in Fig. As shown in Figure 1A, the magnet is fixed to one end of the rotatable object, connected to it, or formed as part of it. Accordingly, the magnet rotates when the rotatable object rotates (e.g., due to a certain force). A magnetic field of the exemplary implementation 100 can then be affected by the rotation of the magnet. Therefore, the first and second gradiometers can determine the angular position of the rotatable object via the sensing elements based on detected components of the magnetic field. In some implementations, the set of magnetic field components detected by the first and second gradiometers consists of magnetic field components perpendicular to the axis of rotation.

[0017] As it is in Fig. As shown in Figure 1B, the first gradiometer consists of detection elements 1 and 2, and the second gradiometer consists of detection elements 3 and 4. Detection elements 1 and 2 form the first gradiometer because they are aligned along a first axis, and detection elements 3 and 4 form the second gradiometer because they are aligned along a second axis. The first gradiometer can be configured to detect a gradient of a first component of the magnet's magnetic field (e.g., an x-component), and the second gradiometer can be configured to detect a gradient of a second component of the magnetic field (e.g., a y-component). A first pair of gradient signals can be detected by determining the first component (x-field component) at the positions of detection elements 1 and 2, where the positions are spaced apart at least in the direction of the first component (x-direction).A second pair of gradient signals can be acquired by determining the second field component at the positions of acquisition elements 3 and 4, where the positions are spaced apart at least in the direction of the second field component (y-direction). The first axis can lie in a first plane perpendicular to the rotation axis, and the second axis can lie in a second plane perpendicular to the rotation axis. In some implementations, the first and second planes are the same plane (i.e., the first and second planes are identical).

[0018] As further explained in Fig. As shown in Figure 1B, a first gradiometer center (e.g., a point along the first axis that is a midpoint (half the distance) between sensing element 1 and sensing element 2) and a second gradiometer center (e.g., a point along the second axis that is a midpoint (half the distance) between sensing element 3 and sensing element 4) can be offset from the center of the rotation axis. Furthermore, in some implementations, a gradiometer intersection point (e.g., where the first and second axes intersect) can be offset from the first gradiometer center and / or the second gradiometer center. Additionally, the gradiometer intersection point can be offset from the center of the rotation axis. In some implementations, the first gradiometer is symmetrically aligned with a second gradiometer relative to a radius extending from the center of the rotation axis.For example, the detection elements 1 and 2 can be designed to be symmetrical to the detection elements 4 and 3, relative to a radial axis passing through the gradiometer interface and the center of the axis of rotation.

[0019] In some implementations, the gradiometer interface may be aligned with the center of the rotation axis. In some implementations, the first and second gradiometers may be arranged on a substrate such that sensing element 1 and sensing element 2 are essentially at the maximum available distance from each other, and sensing element 3 and sensing element 4 are at the maximum available distance from each other (e.g., according to a specially designed layout of, or relationship between, the first and second gradiometers).

[0020] The maximum distances between detection elements 1 and 2 or detection elements 3 and 4 can be based on the dimensions of the substrate (e.g., a semiconductor chip) of the magnetic sensor that includes the first gradiometer and the second gradiometer.

[0021] The magnetic sensor can determine the angular position based on signals received from the first and second gradiometers. In some implementations, the magnetic sensor can normalize a first gradiometer signal from the first gradiometer and a second gradiometer signal from the second gradiometer based on a set of predefined signal offsets and gains. These predefined signal offsets and / or gains can be based on the design of the exemplary implementation 100, one or more characteristics of the magnet, and / or one or more characteristics of the sensing elements. Therefore, the magnetic sensor can obtain a normalized gradiometer signal from the first and second gradiometer signals. Based on this normalized gradiometer signal, the magnetic sensor can then determine the angular position of the magnet and, accordingly, the rotatable object.

[0022] Therefore, exemplary implementation 100 can increase inhomogeneity between the detection elements of the first and second gradiometers. Furthermore, positioning the magnetic sensor such that the center of the first and / or second gradiometer is offset from the axis of rotation can increase the inhomogeneity of the signals detected by the detection elements of the first and second gradiometers. Consequently, the magnetic sensor can detect disturbances in the magnetic field of the magnetic field sensor arrangement more accurately.

[0023] Furthermore, the exemplary implementation represents 100 of Fig. 1A and Fig. 1B provides a magnetic sensor arrangement that allows the magnetic sensor to maintain a relatively small size (e.g., less than 10 mm). For example, by arranging the first and second gradiometers on a single chip of the magnetic sensor, the magnetic sensor can have the same or smaller dimensions as previously used magnetic sensors. Furthermore, appropriately positioning the magnetic sensor relative to the center of the axis of rotation does not affect the size of the magnetic sensor (e.g., it does not require increasing the size of the magnetic sensor).

[0024] As shown above, Fig. 1A and Fig. 1B is provided merely as an example. Other examples are possible and may differ from what is described in relation to Fig. 1A and Fig. 1B was described.

[0025] Fig. Figure 2 is a diagram of an exemplary environment 200 in which magnetic arrangements, devices, systems and / or methods described herein can be implemented. As shown in Fig. As shown in Figure 2, the environment 200 can be a rotatable object 205 (that of the rotatable shaft of Fig. 1A and Fig. 1B corresponds), which can be positioned with respect to the center of a rotation axis 210, a magnet 215 (which corresponds to the magnet of Fig. 1A and Fig. 1B), which is connected to the rotatable object 205, a magnetic sensor 220 (which corresponds to the magnetic sensor of Fig. 1A and Fig. 1B can correspond) and include a control 225.

[0026] The rotatable object 205 is an object for which an angular position and / or the like is of interest for a specific application. For example, the rotatable object 205 may be part of a mechanical system of a machine (e.g., a vehicle, a production machine, an industrial machine, an agricultural machine, an application, and / or the like). In some implementations, the rotatable object 205 is cylindrical. In such implementations, the radius of the rotatable object 205 may be approximately 5 mm. In some implementations, the rotatable object 205 may rotate about the center of the axis of rotation 210. The center of the axis of rotation 210 may correspond to a designed center of a rotation axis associated with the rotatable object 205.

[0027] In some implementations, the rotatable object 205 is connected to the magnet 215 (e.g., attached to it, coupled to it, fixed to it, embedded in it, formed as part of it, and / or the like). Accordingly, the magnet 215 can be configured to rotate together with the rotatable object 205, such that a rotation or angular position of the magnet 215 corresponds to a rotation or angular position of the rotatable object 205, as described herein.

[0028] Magnet 215 can be diametrically magnetized, so that when magnet 215 rotates, it does not generate a rotationally symmetric magnetic field. For example, magnet 215 can comprise a first half forming a north pole (N) and a second half forming a south pole (S), so that magnet 215 has a pole pair.

[0029] In some implementations, the magnet 215 can have more than one pole pair without restriction. Additionally or alternatively, the magnet 215 can comprise a dipole magnet, a permanent magnet, an electromagnet, a magnetic tape, an axially magnetized magnet, and / or the like.

[0030] In some implementations, the magnet 215 can be made of a ferromagnetic material (e.g., hard ferrite) and can generate a magnetic field. Furthermore, in some implementations, the magnet 215 can incorporate a rare-earth magnet, which can be advantageous due to the intrinsically high magnetic field strength of rare-earth magnets.

[0031] In some implementations, a dimension of the magnet 215 (e.g., length, width, height, diameter, radius, and / or the like) may range from about 1 mm to about 15 mm, such as 5 mm. As a particular example, the magnet 215 may be cylindrical and have a thickness or height of about 5 mm or a radius of about 5 mm. In some implementations, the magnet 215 may include a recess or notch that accommodates the rotatable object 205. Although the magnet 215 is described primarily as cylindrical in exemplary implementations herein, it may also have other shapes, such as a ring shape, a cubic shape, an ellipsoidal shape, a triangular shape, a polygonal shape, and / or the like.

[0032] In some implementations, the magnet 215 can be configured according to a reference direction associated with the magnetic sensor 220. Using a Cartesian coordinate system with x, y, and z axes of the magnet 215, the z-axis can be the center of the rotation axis 210, and the x- and y-axes are perpendicular to each other and to the z-axis. In some implementations, the magnetization of the magnet 215 at the start of the rotation (e.g., when the rotatable object 205 and the magnet 215 are at rest) can be aligned with the x-axis. In other words, the dipole moment of the magnet 215 points in the x-direction. As the rotation begins, the direction in which the dipole moment points rotates within the x,y-plane of the magnet 215.

[0033] In some implementations, the magnet 215 may be connected to the rotatable object 205 in an asymmetrical manner. For example, a central axis of the magnet 215 may not be aligned with the center of the rotation axis 210. Although the magnet 215 is shown with sharp edges / corners, the edges and / or corners of the magnet 215 may be rounded.

[0034] The magnetic sensor 220 from Fig. 2 comprises one or more devices for detecting one or more components of a magnetic field of the magnet 215 for use in determining an angular position of the rotatable object 205 (e.g., based on a position of the magnet 215 relative to the magnetic sensor 220). The magnetic sensor 220 can detect the magnetic field generated by the magnet 215 asymmetrically to determine an angular position of the magnet 215 and, consequently, of the rotatable object 205. For example, the magnetic sensor 220 can comprise one or more circuits (e.g., one or more integrated circuits) that operate to detect a set of components of the magnetic field generated by the magnet 215. According to some implementations, a set of components can include one or more components of a magnetic field intensity (e.g., a magnetic flux density and / or a magnetic field strength), a magnetic field magnitude, a magnetic field direction, or the like.Accordingly, a magnetic sensor 220 can provide an output signal (e.g. to the controller 225) that indicates a physical quantity (e.g. a component of the magnetic field).

[0035] The magnetic sensor 220 can be a three-dimensional (3D) magnetic sensor capable of detecting three directional components of a magnetic field (e.g., an x-component corresponding to the x-axis of the magnetic sensor 220, a y-component corresponding to the y-axis of the magnetic sensor 220, and a z-component corresponding to the z-axis of the magnetic sensor 220). For example, the magnetic sensor 220 can comprise a semiconductor substrate that includes detection elements and / or gradiometers. The semiconductor substrate can be a polygon (e.g., a tetragon, a pentagon, a hexagon, and / or the like) and have an area defined by the positions of the detection elements and / or gradiometers. The area can, for example, have a length corresponding to the length of a first gradiometer and a width corresponding to the length of a second gradiometer of the semiconductor substrate (e.g.,(if the first and second gradiometers are configured to be perpendicular to each other). In such a case, the area can be a tetragon (e.g., a square, a rectangle, and / or the like). Additionally or alternatively, the area can have a perimeter defined by the positions of the sensing elements and / or gradiometers. For example, the area can be a polygon with vertices defined by the positions of the sensing elements or gradiometers. In some aspects, the vertices can correspond to the positions of the sensing elements, and / or the vertices of the polygon can depend on the positions of the sensing elements, so that the vertices of the polygon allow the edges of the polygon to form a shape or area encompassing each of the sensing elements or gradiometers of the magnetic sensor 220.

[0036] In some implementations, the sensing elements and / or the gradiometers of the magnetic sensor 220 may be configured to detect a set of magnetic field components (e.g., x-components and y-components) in planes perpendicular to the center of the axis of rotation 210. In some implementations, the magnetic sensor 220 may include an integrated circuit that incorporates an integrated controller 225 (e.g., such that an output of the magnetic sensor 220 may include information describing a position of the magnet 215 and / or a position of the rotatable object 205). In some implementations, the magnetic sensor 220 may include one or more sensing elements (which, for example, correspond to the sensing elements of Fig. 1A and Fig. 1B), which are configured to detect one or more components of the magnetic field generated by the magnet 215. The detection elements may include one or more gradiometers and / or be configured to form them as described herein. In some implementations, the magnetic sensor 220 may include an analog-to-digital converter (ADC) to convert analog signals received from the detection elements into digital signals to be processed by the magnetic sensor 220 (e.g., by a digital signal processor (DSP)).

[0037] In some implementations, the magnetic sensor 220 can be positioned relative to the magnet 215 such that it can detect one or more components of the magnetic field generated by the magnet 215. For example, the magnetic sensor 220 can be positioned away from one end of the rotatable object 205 that encompasses the magnet 215 to detect a magnetic field component of the magnet 215 as the magnet 215 rotates about the axis of rotation 210. In some implementations, an air gap (e.g., at least 1 mm) can exist between the magnetic sensor 220 and the magnet 215 when the magnet 215 rotates about the axis of rotation 210 close to the magnetic sensor 220. In some implementations, the magnetic sensor 220 can be offset from the center of the axis of rotation 210. For example, the center of the magnetic sensor 220 may not be aligned with the center of the axis of rotation 210.Furthermore, in some implementations, the magnetic sensor 220 can be offset from the center of the rotation axis 210 relative to one or more dimensions and / or positions of the one or more gradiometers in the magnetic sensor 220.

[0038] In some implementations, the magnetic sensor 220 can derive the angular position of the magnet 215 during rotation based on signals from the gradiometers of the magnetic sensor 220. The signals can include measurement information indicating measurements of a detected magnetic field component performed by the respective gradiometers. For example, the magnetic sensor 220 can have an x-gradiometer with sensing elements 1 and 2 (which measure the magnetic field component B). x capture and measurements of B x 1 or B x 2) and a y-gradiometer with sensing elements 3 and 4 (which measure the magnetic field component B) y capture and measurements of B y 3 or By 4 provide). The magnetic sensor 220 can provide a signal (S x = B x1 -B x2 ) from the x-radiometer and a signal (S y = B y3 -B y4 ) from the y-radiometer based on corresponding signal gains (c x , c y ) and offsets (off x , off y ) normalize as follows: Snx=Sx*cx+offx,Syn=Sy*cy+offy where S xn a normalized signal from the first gradiometer corresponds to and S yn a normalized signal from the second gradiometer. In such cases, the signal gains (c) can be x , c y ) depend on the configuration of the first gradiometer and the second gradiometer within the magnetic sensor 220, a design of the magnetic sensor 220, and / or one or more characteristics of the magnet 215. Furthermore, the offsets (off) can x , off y) based on a configuration of the first gradiometer and / or the second gradiometer. Furthermore, the magnetic sensor 220 can transmit the normalized signals (S xn , S yn ) combine to obtain a normalized gradiometer signal as follows: Snx2=Snx*c2+Syn where c2 can be a constant based on one or more characteristics of the magnetic sensor 220 or the environment 200. Finally, the magnetic sensor 220 can calculate the following from the normalized gradiometer signal: phi=arctan2(Sxn2;Syn) where phi is the angular position of the magnet 215 and / or the rotatable object 205.

[0039] In some implementations, the magnetic sensor 220 can be configured with imaging information associated with determining the angular position (or rotation angle) of the rotatable object 205, based on the detected set of components of the magnetic field. The magnetic sensor 220 can store the imaging information in a memory (e.g., read-only memory (ROM) (e.g., electrically erasable programmable read-only memory (EEPROM)), random-access memory (RAM), and / or another type of dynamic or static storage device (e.g., flash memory, magnetic memory, optical memory, etc.)) of the magnetic sensor 220. The imaging information can include information associated with a rotation angle and a set of components of the magnetic field corresponding to that rotation angle.The imaging information can include such information for multiple rotation angles and / or positions of the rotatable object 205. In some implementations, the magnetic sensor 220 can be configured with the imaging information during a manufacturing process associated with the magnetic sensor 220 and / or a rotation angle detection system, a calibration process associated with the magnetic sensor 220, a setup process associated with the magnetic sensor 220, and / or the like.

[0040] During operation, the magnetic sensor 220 can detect the set of components of the magnetic field of the magnet 215. The magnetic sensor 220 can then compare the detected set of magnetic field components with the imaging information and determine the rotation angle of the rotatable object 205 based on the comparison. For example, the magnetic sensor 220 can identify sets of magnetic field components contained in the imaging information that match the detected set of magnetic field components (e.g., within a threshold or that meet a matching threshold). In this example, the magnetic sensor 220 can determine the rotation angle of the rotatable object 205 as the rotation angle that corresponds to the matching imaging information.

[0041] The controller 225 comprises one or more circuits dedicated to determining the rotation angle (and / or position) of the rotatable object 205 and providing information related to the rotation angle of the rotatable object 205. The controller 225 may, for example, include a processor, an integrated circuit, a control circuit, a feedback circuit, and / or the like. The controller 225 may receive input signals from one or more sensors (e.g., from a digital signal processor (DSP) of the magnetic sensor 220), such as one or more magnetic sensors 220, process the input signals (e.g., using an analog signal processor, a DSP, and / or the like) to generate an output signal, and provide the output signal to one or more other devices or systems.For example, the controller 225 can receive one or more input signals from the magnetic sensor 220 and can use the one or more input signals to generate an output signal that has the angular position of the rotatable object 205 to which the magnet 215 is connected.

[0042] The number and arrangement of the in Fig. The devices shown in Figure 2 are provided as an example. In practice, there may be additional devices, fewer devices, different devices, or devices arranged differently than those shown. Fig. 2 are shown. Furthermore, two or more of the in Fig. The devices shown in the two shown may be implemented in a single device or a single device in Fig. The device shown in Figure 2 can be implemented as multiple distributed devices. Additionally or alternatively, a set of devices (e.g., one or more devices) of environment 200 can perform one or more functions that are described as being performed by another set of devices of environment 200.

[0043] Fig. Figure 3 is a diagram of exemplary elements of the magnetic sensor 220. Fig. 2. As shown, the magnetic sensor 220 can comprise a set of sensing elements 310-1 to 310-N (where N is an integer and N ≥ 1) (which can be referred to collectively as “sensing elements 310” or individually as “sensing element 310”), an analog-to-digital converter (ADC) 320, a digital signal processor (DSP) 330, a memory 340 and a digital interface 350.

[0044] The sensing element 310 comprises an element for sensing a component or set of components of a magnetic field present at the magnetic sensor 220 (e.g., the magnetic field generated by the magnet 215). For example, the sensing element 310 may comprise a Hall-based sensing element, such as a vertical Hall effect (VHall) device, which operates based on the Hall effect. As another example, the sensing element may comprise a magnetoresistive (MR)-based sensing element (which may also be referred to as an XMR), elements that incorporate a magnetoresistive material (e.g., nickel-iron (NiFe)), where the electrical resistivity of the magnetoresistive material may depend on the strength and / or direction of the magnetic field present at the magnetoresistive material.Here, the detection element 310 can be an anisotropic MR (AMR), a giant MR (GMR) effect, a tunnel MR (TMR), a magnetic tunneling junction (MTJ) and / or the like.

[0045] In some implementations, the sensing element 310 may be a thin-film XMR such that two dimensions (x, y) of the sensing element 310 are much larger than a third orthogonal dimension (z). In such cases, vector components parallel to the sensing element 310 are referred to as in-plane components of the magnetic field. Furthermore, a plane parallel to the flat sides of the sensing element 310 may be referred to as the “XMR plane.” Vector components that are orthogonal or perpendicular to the XMR plane may be referred to as out-of-plane components of the magnetic field.

[0046] Detection elements 310 can be sputtered onto a substrate (e.g., a semiconductor chip) of the magnetic sensor 220. Accordingly, a surface of the substrate can be the same as the XMR plane or xy plane of the magnetic sensor 220. Detection elements 310 can be high-field or saturated XMRs (e.g., XMRs corresponding only to components of the magnetic field in the same plane). Additionally or alternatively, detection elements 310 can be low-field or unsaturated XMRs (e.g., XMRs corresponding only to components of the magnetic field outside the plane). In some implementations, the substrate is square. The substrate can be, for example, a semiconductor (e.g., a silicon semiconductor piece or silicon chip) with a width w and a height h. In some implementations, the width and / or height is between 1.00 mm and 3.00 mm.

[0047] In some implementations, the magnetic sensor 220 can comprise one or more gradiometers, each consisting of one or more respective sets of sensing elements 310. For example, the magnetic sensor 220 can comprise a first gradiometer, which includes a first sensing element 310-1 and a second sensing element 310-2, which operate to detect a set of components of the magnetic field at the first sensing element 310-1 and the set of components at the second sensing element 310-2.

[0048] The ADC 320 can include an analog-to-digital converter that converts an analog signal from the set of sensing elements 310 into a digital signal. For example, the ADC 320 can convert analog signals received by the set of sensing elements 310 into digital signals to be processed by the DSP 330. The ADC 320 can then supply the digital signals to the DSP 330. In some implementations, the magnetic sensor 220 can include one or more ADCs 320.

[0049] The DSP 330 can comprise a digital signal processing device or a collection of digital signal processing devices. In some implementations, the DSP 330 can receive digital signals from the ADC 320 and process the digital signals to form output signals (e.g., intended for the controller 225, as described in Fig. 2 is shown), such as output signals that are assigned to determining the angular position of the magnet 215 around the center of the axis of rotation 210.

[0050] Memory 314 can comprise read-only memory (ROM) (e.g., electrically erasable programmable read-only memory (EEPROM)), random-access memory (RAM), and / or another type of dynamic or static storage device (e.g., flash memory, magnetic memory, optical memory, etc.) that stores information and / or instructions for use by the magnetic sensor 220. In some implementations, memory 340 can store information associated with the processing performed by the DSP 330. Additionally or alternatively, memory 340 can store configuration values ​​or parameters for the set of sensing elements 310 and / or information for one or more other elements of the magnetic sensor 220, such as the ADC 320 or digital interface 350.

[0051] The digital interface 350 can include an interface through which the magnetic sensor 220 can transmit information to and / or from another device, such as a controller 225 (see Fig. 2) can receive and / or supply. For example, the digital interface 350 can supply the output signal, determined by the DSP 330, to the controller 225 and can also receive information from the controller 225.

[0052] The number and arrangement of the in Fig. The three elements shown are examples. In practice, the magnetic sensor can use 220 additional elements, fewer elements, different elements, or elements arranged differently than those shown. Fig. Figure 3 shows the following. Additionally or alternatively, a set of elements (e.g., one or more elements) of the magnetic sensor 220 can perform one or more functions that are described such that the same functions are performed by another set of elements of the magnetic sensor 220.

[0053] Fig. Figure 4 is a diagram of an exemplary gradiometer 400, which is used in the magnetic sensor of Fig. It may contain 3. As it is in Fig. As shown in Figure 4, the gradiometer 400 is represented by a half-bridge circuit comprising a first sensing element 310-1 and a second sensing element 310-2 and supplied with voltage from a supply (V Versorgung ) is supplied and an output signal (V AusThe first sensing element 310-1 and the second sensing element 310-2 are both configured to detect a magnetic field in the same direction (+x). The gradiometer 400 responds to differences in the magnetic field detected by the first sensing element 310-1 and the second sensing element 310-2. For example, if the first sensing element 310-1 is separated from the second sensing element 310-2 by a certain distance V Aus is spaced apart, V Aus The difference in the magnetic field at the two different positions is addressed by responses to the gradient (e.g., the inclination of the field relative to the spatial coordinate of the field). In some implementations, the distance can be at least 1 mm.

[0054] In some implementations, both the first sensing element 310-1 and the second sensing element 310-2 are implemented on the same substrate (e.g., the same silicon chip). In such cases, both the first sensing element 310-1 and the second sensing element 310-2 can be fabricated essentially simultaneously using the same process (e.g., by using the same doping, the same etching direction of the substrate, exposing the substrate to the same amount of dopant, and / or the like). Furthermore, when formed or positioned on the same substrate, the first sensing element 310-2 and the second sensing element 310-2 can be positioned relatively accurately relative to each other (e.g., using lithography, which has a much lower tolerance than if the first sensing element 310-1 and the second sensing element 310-2 were on separately aligned substrates).In some implementations, the substrate can have a dimension (e.g., a length and / or width) of at least 2 mm. Accordingly, in such cases, the first sensing element 310-1 and the second sensing element 310-2 can be spaced at least 2 mm apart. In some implementations, a defined distance between the first sensing element 310-1 and the second sensing element 310-2 can be based on one or more characteristics (e.g., magnetization, size, and / or the like) of the magnet 215 and / or the magnetic field generated by the magnet 215.

[0055] As mentioned above, Fig. 4 is merely an example. Other examples are possible and may differ from what is stated in relation to Fig. 4 was described.

[0056] Fig. Figures 5-7 are diagrams relating to exemplary implementations 500, 600, and 700 of a magnetic sensor arrangement described herein. In exemplary implementations 500, 600, and 700, a substrate of the magnetic sensor 220 (hereinafter referred to as the “substrate”) comprises an x-gradiometer with sensing elements 1 and 2 (shown as “1” and “2”) aligned along a first axis (shown as “dx”), and a y-gradiometer with sensing elements 3 and 4 (shown as “3” and “4”) aligned along a second axis (shown as “dy”). In some implementations, the first axis runs between a center of gravity of sensing element 1 and a center of gravity of sensing element 2, and the second axis runs between a center of gravity of sensing element 3 and a center of gravity of sensing element 4.The detection elements 1 and 2 are symmetrical along a radius (shown as the "line of symmetry") extending from the center of the rotation axis 210. An x-axis and a y-axis are shown, where the x-axis may correspond to a reference direction of the magnetization of magnet 215. In some implementations, the first axis is parallel to the x-axis and the second axis is parallel to the y-axis, and / or the first and second axes are perpendicular to each other. The symmetry of the arrangement of the x- and y-gradiometers (at a 45-degree angle from the x-axis) ensures that the signals S. x and S y The values ​​of the x-radiometer and the y-radiometer are nominally the same in terms of magnitude and shape, but are shifted by the angular position.

[0057] In the exemplary implementations 500, 600, and 700, detection element 1 is placed as close as possible to a left edge of the substrate, and detection element 3 is placed as close as possible to a bottom edge of the substrate. Furthermore, detection element 2 is shifted from detection element 1 parallel to the x-axis and as far as possible to the right edge of the substrate, and detection element 4 is shifted parallel to the y-axis from detection element 3 and as far as possible to the top edge of the substrate. Accordingly, there can be a maximum distance along a first edge direction between detection element 1 and detection element 2 of the x-radiometer, and a maximum distance along a second edge direction between detection element 3 and detection element 4 of the y-radiometer in the exemplary configurations of the detection elements in the exemplary implementations 500, 600, and 700.Therefore, in some implementations, a maximum output signal from the x-radiometer and the y-radiometer can be achieved in the respective configurations of the example implementations 500, 600 and 700.

[0058] In the exemplary implementation of 500 of Fig. 5 The substrate is arranged relative to the rotatable object 205 and / or the magnet 215 such that a gradiometer interface between the first axis and the second axis is aligned with the center of the rotation axis 210. As further shown in Fig. As shown in Figure 5, the gradiometer interface is offset from the center of the x-gradiometer and the center of the y-gradiometer. In some implementations, the gradiometer interface may be offset from either the center of the x-gradiometer or the center of the y-gradiometer.

[0059] If the gradiometer interface is aligned with the axis of rotation, as in the exemplary implementation 500 of Fig. 5 is shown, and when the magnet 215 is in a zero position (e.g., when the dipole moment is aligned with the x-axis), the y-radiometer B can y Output = 0, and if the same is in a 90-degree position (e.g., if the dipole moment is shifted by 90 degrees or along the y-axis), the x-Gradiometer can display dB x =B x1 -B x2 Output =0. In other words, there are no offsets to consider, since the gradiometer interface is formed with the center of the rotation axis. Accordingly, the substrate configuration, as shown in the exemplary implementation 500, can ensure that S x The x-radiometer is at its maximum when S yThe y-radiometer intersects a zero point (and vice versa), providing a phase shift of exactly 90 degrees. Accordingly, the substrate configuration in the exemplary implementation 500 can be advantageous when calculating the angular position.

[0060] However, in some cases the signal strength of the x-radiometer and / or the y-radiometer may be blocked if the example configuration of Fig. 5 is used. For example, measurements of the magnetic field component B x The relationship between x and y is shown by graph 510 when magnet 215 is at a zero position and the dipole of magnet 215 points in a negative x-direction. Therefore, the measurements of B xThe curve along x shows a flat region (around x = 0), an ascending steep region (in the negative x-direction), and a descending steep region (in the positive x-direction). Since measurements by the x-gradiometer (shown by "1" and "2") are both taken near the flat region, the strength of S x relatively small, (since B x2 -B x1 will be relatively small). Furthermore, if the substrate shifts in the positive x-direction (e.g., due to assembly tolerances), the size of S would change. x change. To make a change to S xDespite a shift in the x-direction to avoid (in order to allow certain tolerances), some implementations described herein can form the substrate such that it is offset from the center of the axis of rotation 210, so that the axis of rotation 210 is not aligned with the area of ​​the substrate (e.g., is not aligned above or below it) or does not pass through it.

[0061] In the exemplary implementation 600 of Fig. 6 The substrate is arranged relative to the rotatable object 205 and / or the magnet 215 such that one corner of the substrate is aligned with the center of the axis of rotation. Accordingly, in the exemplary implementation 600, the gradiometer interface between the first and second axes of the x-gradiometer and the y-gradiometer is offset from the center of the axis of rotation 210. As further shown in Fig. As shown in Figure 6, the gradiometer interface is offset from the center of the x-gradiometer and the center of the y-gradiometer. In some implementations, the gradiometer interface may be offset from either the center of the x-gradiometer or the center of the y-gradiometer.

[0062] If the gradiometer interface is not aligned with the axis of rotation, as in the exemplary implementation 600 of Fig. 6 is shown, and when the magnet 215 is at a zero position (e.g., when the dipole moment is aligned with the x-axis), the y-gradiometer can display an output that dBy (B y1 -B y2 ) is approximately zero (as opposed to exactly zero as in connection with Fig. 5 is described), and if the same is in a 90-degree position (e.g., if the dipole moment is shifted by 90 degrees or shifted along the y-axis), the x-gradiometer can display an output that dB xapproximately 0 (as opposed to exactly zero, as in connection with Fig. 5 is described). In other words, there may be an offset to account for because the gradiometer interface is not aligned with the center of the rotation axis. Although the offset may need to be taken into account (e.g., when the magnetic sensor 220 normalizes and / or combines signals from the x-gradiometer and the y-gradiometer), the substrate configuration, as shown in the exemplary implementation 600, can ensure that S x The x-radiometer is at its maximum when S y The y-radiometer intersects a zero point (and vice versa), providing an almost (if not exact) 90-degree phase shift. Accordingly, the substrate configuration in the exemplary implementation 600 can be advantageous when calculating the angular position.

[0063] Furthermore, the substrate configuration in example implementation 600 shifts the substrate relative to the configuration of example implementation 500. Therefore, the signal strength S x and / or S y The signal strength can be improved relative to that of the exemplary implementation 500. As shown by graph 610, for example, detection element 1 and detection element 2 were shifted in the positive x-direction (corresponding to the shift of the substrate) relative to the exemplary implementation 500, so that detection element 1 is closer to the descending steep region of B. x -Measurements is and the detection element 2 B x continue along the descending steep region of the B x -Measurements recorded. Therefore, the signal strength of S x (B x2 -B x1) can be improved, and the tolerance for a shift in the x-direction can be improved relative to the exemplary implementation 500. However, as shown by graph 610, the capture element 1 is not along the descending steep region of B. x Measurements are aligned to completely avoid the effects of any shift in the x-direction. Some implementations described herein shift the substrate to ensure that both capture elements 1 and capture elements 2 are aligned. x Measure in the descending steep region to maximize signal strength and account for a shift in the x-direction.

[0064] In the exemplary implementation 700 of Fig. In 7, the substrate is arranged relative to the rotatable object 205 and / or the magnet 215 such that one corner of the substrate is offset from the center of the axis of rotation, and the center of the axis of rotation is not aligned with or passes through any area of ​​the substrate. Accordingly, in exemplary implementation 700, the gradiometer interface between the first and second axes of the x-gradiometer and the y-gradiometer is offset further from the center of the axis of rotation 210 relative to exemplary implementation 600. Fig. 6. As further explained in Fig. As shown in Figure 7, the gradiometer interface is offset from the center of the x-gradiometer and the center of the y-gradiometer. In some implementations, the gradiometer interface may be offset from either the center of the x-gradiometer or the center of the y-gradiometer.

[0065] If the gradiometer interface is not aligned with the axis of rotation, as in the exemplary implementation 700 of Fig. As shown in Figure 7, a greater offset may need to be considered, since the gradiometer interface is essentially not aligned with the center of the axis of rotation. Furthermore, a phase shift between S may occur. x from the x-radiometer and S y The y-radiometer is not phase-shifted by 90 degrees (e.g., the phase shift may be less than 80 degrees), which can cause additional complexity in calculating the angular position of magnet 215. x and S y However, they can be manipulated (e.g., normalized and / or combined using reinforcements and / or offsets) to account for the offset. For example, the manipulation of S x and S ybased on the distance between the detection element 1 and the detection element 2, the radial displacement of the substrate from the center of the axis of rotation, the characteristics of the magnet 215 (e.g., the size of the magnet 215, the size of an air gap between the substrate and the magnet 215, and / or the like). As an example, to demonstrate the non-orthogonality of S x and S y To take this into account, the reference directions can be rotated from the xy-direction by manipulating S x and S y , as shown above in equations 2 and 3, where Sx2=c2*Sx1+Sy, and phi=arctan2(Sx2,Sy)).

[0066] Furthermore, the substrate configuration in example implementation 700 shifts the substrate further relative to the configuration of example implementation 600. Therefore, the signal strength of S x and / or S yrelative to the signal strength in the example implementation 600, the detection element 1 and detection element 2, for example, were shifted in the positive x-direction (corresponding to the shift of the substrate) relative to the example implementation 600, such that detection element 1 is located within the descending steep region of B. x -Measurements are, together with the detection element 2. Therefore, the signal strength of S x (B x2 -B x1 ) improved and tolerance for a shift in the x-direction is further improved relative to the exemplary implementation 600. Accordingly, the exemplary implementation 700 can achieve a relatively high signal strength of S x to achieve, despite a shift of the substrate in the x-direction, by ensuring that both the detection element 1 and the detection element 2 B xMeasure in the sloping, steep region.

[0067] Although the preceding examples refer to exemplary configurations, the displacements in the x-direction and corresponding signal strengths S x It should be noted that the configurations of the exemplary implementations 500, 600 and 700 equally tolerate shifts in the y-direction and corresponding signal strengths of S. y can endure.

[0068] As shown above, Fig. 5-7 are merely examples. Other examples are possible and may differ from what is stated in relation to Fig. 5 to 7 is described.

[0069] Fig. 8 and Fig. Figure 9 are diagrams relating to exemplary implementations 800 and 900 of a magnetic sensor arrangement described herein. In exemplary implementations 800 and 900, a substrate of a magnetic sensor 220 (hereinafter referred to as the “substrate”) comprises a first gradiometer with sensing elements 1 and 2 (shown as “1” and “2”) aligned along a first axis (shown as “d12”), and a second gradiometer with sensing elements 3 and 4 (shown as “3” and “4”) aligned along a second axis (shown as “d34”). In some implementations, the first axis runs between a center of gravity of sensing element 1 and a center of gravity of sensing element 2, and the second axis runs between a center of gravity of sensing element 3 and a center of gravity of sensing element 4. As shown in Fig. 8 and Fig. As shown in Figure 9, at least one of the sensing elements of the first and second gradiometers is not aligned with the magnet 215 (e.g., aligned above or below it). For example, the distance between sensing element 2 and the center of the axis of rotation may be greater than the radius of the magnet 215 (or the distance from a circumference of the magnet 215 to the center of the axis of rotation 210). In some implementations, all sensing elements of the substrate may be aligned with the magnet 215 (e.g., with a plane defined by the circumference of the magnet 215). Therefore, the distance between each of the sensing elements 1 to 4 and the center of the axis of rotation 210 may be less than a radius of the magnet 215.

[0070] The detection elements 1 and 2 can be symmetrical along a radius (shown as a "line of symmetry") extending from the center of the rotation axis 210. An x-axis and a y-axis are shown, where the x-axis can correspond to a reference direction of the magnetization of magnet 215. However, the signals S12 and S34 from the first gradiometer and the second gradiometer, respectively, can have different magnitudes (e.g., due to misalignment with respective components of the magnetic field), but can be scaled to normalized amplitudes before the angular position (phi) is calculated.

[0071] As it is in Fig. As shown in Figure 8, in the configuration of Example Implementation 800, sensing element 1 is placed as close as possible to a left edge of the lower left corner of the substrate, and sensing element 3 is placed as close as possible to a lower edge of the lower left corner of the substrate. Furthermore, sensing element 2 is placed as far as possible to a right side edge of the upper right corner of the substrate, and sensing element 4 is placed as far as possible to an upper edge of the upper right corner of the substrate. Accordingly, there can be a maximum distance between sensing element 1 and sensing element 2 of the x-radiometer and a maximum distance between sensing element 3 and sensing element 4 of the y-radiometer in the configuration of the sensing elements of Example Implementation 800.Therefore, in some implementations, a maximum output signal of 800 can be achieved from the x-radiometer and the y-radiometer in the respective configuration of the exemplary implementation.

[0072] In exemplary implementation 800, the substrate is arranged relative to the rotatable object 205 and / or the magnet 215 in a similar manner to exemplary implementation 700, such that one corner of the substrate is offset from the center of the axis of rotation and the center of the axis of rotation is not aligned with or passes through any region of the substrate. However, in exemplary implementation 800, the first axis of the first gradiometer is oriented along a direction approximately 40 degrees relative to the positive x-direction, and the second axis of the second gradiometer is oriented along a direction approximately 50 degrees relative to the positive x-direction. In exemplary implementation 800, sensing element 1 and sensing element 2 are sensitive to the same component of the magnetic field (e.g., B). xor rotated 30 degrees clockwise from the positive x-direction) and detection element 3 and detection element 4 are sensitive to the same component of the magnetic field (e.g., B y or 30 degrees counterclockwise from the y-direction).

[0073] In some implementations, the configuration of the sensing elements in the example implementation can save 800 surface area (e.g., chip space) of the substrate. Since the sensing elements are not located in all four corners of the substrate, the remaining chip area can, for example, be removed and / or used for other circuit layouts. In some implementations, further surface area of ​​the substrate can be saved by reshaping the substrate (e.g., into a rectangle).

[0074] As it is in Fig. As shown in Figure 9, in the configuration of the exemplary implementation 900, the substrate has a rectangular shape and is longitudinally shifted along the line of symmetry. Furthermore, the first detection element is placed in a first corner (lower left corner) of the substrate, and detection element 2 is placed in a second corner (upper right corner) opposite the first corner and detection element 1. Additionally, in the exemplary implementation 900, detection element 3 is placed in a third corner (lower right corner) of the substrate, and detection element 4 is placed in a fourth corner (upper left corner) opposite the third corner and detection element 3.

[0075] The exemplary configuration of the exemplary implementation 900 can save hardware resources and / or a size of the substrate (and thus the size of the magnetic sensor 220), while maintaining the accuracy in determining an angular position of the magnet 215 and / or the rotatable object 205.

[0076] As shown above, Fig. 8 and Fig. 9 is merely an example. Other examples are possible and may differ from what is stated in relation to Fig. 8 and Fig. 9 was described.

[0077] Fig. Figure 10 is a flowchart of an exemplary process 1000, which is associated with the use of a magnetic sensor array with multiple gradiometers as described herein. In some implementations, one or more process blocks of Fig. 10 are carried out by a machine that is assigned to the manufacture of a magnetic sensor 220.

[0078] As it is in Fig. As shown in Figure 10, process 1000 can involve rotating a magnet at one end of a rotatable object around the center of a rotational axis (block 1010). For example, the magnet 215 can be attached to a rotatable object 205 or be formed as part of it. In some implementations, the magnet object 205 is rotated, causing the magnet 215 to rotate. In some implementations, the rotatable object 205 and / or the magnet 215 are shaped to fit together or be connected to each other.

[0079] As further explained in Fig. As shown in Figure 10, process 1000 can include acquiring a first pair of gradiometer signals at a first and second position and a second pair of gradiometer signals at a third and fourth position, wherein the first, second, third, and fourth positions are offset from the center of the axis of rotation (block 1020). For example, the magnetic sensor 220 can acquire the first pair of gradiometer signals and the second pair of gradiometer signals.

[0080] In some implementations, the first axis is in a first plane and the second axis is in a second plane. In some implementations, the first and second planes are each perpendicular to the axis of rotation. In some implementations, the first gradiometer center is offset from the center of the axis of rotation, and the second gradiometer center is also offset from the center of the axis of rotation. In some implementations, the first and second axes intersect at a gradiometer interface, the method further comprising positioning the gradiometer interface so that it is offset from the center of the axis of rotation. In some implementations, the first axis is configured to be perpendicular to the second axis on a substrate of the magnetic sensor.

[0081] Although Fig. As shown in the 10 example blocks of process 1000, process 1000 may, in some implementations, include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those shown in Fig. 10 are shown. Alternatively, two or more blocks of process 1000 can be carried out in parallel.

[0082] Accordingly, some implementations described herein provide a magnetic sensor array that uses multiple gradiometers to determine the angular position or angle of rotation of a rotatable shaft. According to some implementations, the gradiometers can be configured relative to the center of a rotational axis of the rotatable shaft to accommodate disturbances in a magnetic field associated with the rotatable object and / or to provide a relatively high signal strength compared to previous techniques. Furthermore, some implementations described herein can tolerate misalignment or displacement of the magnetic sensor relative to a preconfigured position by positioning the magnetic sensor and / or configuring sensing elements within the magnetic sensor to measure one or more components of the magnetic field that provide the highest signal strength.Therefore, increased accuracy in determining the angular position of the rotatable object can be achieved compared to previous techniques.

[0083] The above disclosure provides a representation and description, but is not intended to be exhaustive or to limit the implementations to the exact form disclosed. Modifications and variations are possible with respect to the above disclosure or may be obtained from the application of the implementations.

[0084] As used herein, the term "component" should be understood broadly as hardware, firmware, or a combination of hardware and software.

[0085] Some implementations are described herein in connection with thresholds. Meeting a threshold, as used herein, may refer to a value that is greater than the threshold, more than the threshold, higher than the threshold, greater than or equal to the threshold, less than the threshold, less than the threshold, lower than the threshold, less than or equal to the threshold, equal to the threshold, or the like.

[0086] Some implementations are described herein as including either a parallel or a perpendicular relationship. As used herein, "parallel" means that this also covers essentially parallel relationships, and "perpendicular" means that this also covers essentially perpendicular relationships. Furthermore, as used herein, "essentially" refers to the fact that a described measurement, feature, or relationship is within a tolerance (e.g., a design tolerance, a manufacturing tolerance, an industry standard tolerance, and / or the like).

[0087] It is clear that the systems and / or procedures described herein can be implemented in various forms of hardware, firmware, or a combination of hardware and software. The actual specialized control hardware or software code used to implement these systems and / or procedures does not limit the implementations. Thus, the operation and behavior of the systems and / or procedures have been described herein without reference to specific software code—it being clear that software and hardware can be designed to implement the systems and / or procedures based on the description herein.

[0088] Although certain combinations of features are listed in the claims and / or disclosed in the description, these combinations are not intended to limit the disclosure of possible implementations. Indeed, many of these features can be combined in ways not specifically listed in the claims and / or disclosed in the description. Although each dependent claim listed below may depend directly on only one other claim, the disclosure of possible implementations includes each dependent claim in combination with every other claim in the claim set.

[0089] No element, step, or instruction herein should be considered critical or essential unless explicitly stated as such. Furthermore, as described herein, the articles "one," "a," and "a" are to encompass one or more elements and may be used interchangeably herein with "one," "a," "a," or "more." Furthermore, as used herein, the term "sentence" is to encompass one or more elements (e.g., related elements, unrelated elements, a combination of related and unrelated elements, etc.) and may be used interchangeably with "one," "a," "a," or "more." Where only one element is intended, the term "one," "a," or similar language is used. Also, as used herein, the terms "has," "have," or the like are to be open terms.Furthermore, the expression “based on” shall mean “based at least in part on”, unless explicitly stated otherwise.

Claims

[1] A magnetic sensor arrangement having the following features: a magnetic sensor (220) for determining an angular position of a rotatable object (205), wherein the rotatable object (205) is designed to rotate about the center of a rotation axis, and wherein the magnetic sensor (220) comprises a first gradiometer (1, 2) aligned on a first axis and a second gradiometer (3, 4) aligned on a second axis, wherein the first gradiometer (1,2) comprises a first detection element (1) and a second detection element (2), wherein the second gradiometer (3, 4) comprises a third detection element (3) and a fourth detection element (4), wherein the first gradiometer (1, 2) has a first gradiometer center on the first axis and wherein the second gradiometer (3, 4) has a second gradiometer center on the second axis, where the first axis and the second axis are each perpendicular to the axis of rotation, wherein the first gradiometer center is offset from the center of the axis of rotation and the second gradiometer center is offset from the center of the axis of rotation, wherein the first axis and the second axis intersect at a gradiometer interface that is offset from the first gradiometer center or the second gradiometer center, wherein the gradiometer interface is located between the first sensing element (1) and the second sensing element (2) and between the third sensing element (3) and the fourth sensing element (4), and where the first axis and the second axis are not collinear, not orthogonal, and not parallel to each other, the magnetic sensor (220) is intended for: Detect, via the first gradiometer (1, 2) and the second gradiometer (3, 4), a set of magnetic field components of a magnetic field generated by a magnet, where the set of magnetic field components is perpendicular to the axis of rotation; wherein the magnet is designed to rotate together with the rotatable object (205); and Determine, based on the detection of the set of magnetic field components, the angular position of the rotatable object (205). [2] Magnetic sensor arrangement according to claim 1, wherein the first sensing element (1) and the second sensing element (2) are configured to detect a first component of the magnetic field, and the third sensing element (3) and the fourth sensing element (4) are configured to detect a second component of the magnetic field, wherein the first component differs from the second component. [3] The magnetic sensor arrangement according to one of claims 1 to 2, wherein the first sensing element (1) and the second sensing element (2) are designed to be symmetrical to the third sensing element (3) and the fourth sensing element (4) relative to a radial axis passing through the center of the axis of rotation. [4] The magnetic sensor arrangement according to one of claims 1 to 3, wherein the gradiometer interface is offset from the center of the rotation axis of the rotatable object (205). [5] The magnetic sensor arrangement according to any one of claims 1 to 4, wherein the magnetic sensor (220) is configured such that the center of the axis of rotation of the rotatable object (205) is not aligned with or passes through an area associated with the first gradiometer (1, 2) and the second gradiometer (3, 4), wherein the area is a quadrilateral with vertices whose vertices correspond to the positions of the first sensing element (1), the second sensing element (2), the third sensing element (3) and the fourth sensing element (4). [6] The magnetic sensor arrangement according to any one of claims 1 to 5, wherein the magnetic sensor (220) is configured such that the center of the axis of rotation of the rotatable object (205) is not aligned with or passes through an area associated with the first gradiometer (1, 2) and the second gradiometer (3, 4), wherein the area is a quadrilateral with a length based on a length of the first gradiometer (1, 2) and a width corresponding to a length of the second gradiometer (3, 4). [7] The magnetic sensor arrangement according to any one of claims 1 to 6, wherein the magnetic sensor (220), when it determines the angular position of the rotatable object (205), is provided for: Normalizing a first gradiometer signal from the first gradiometer (1,2) and a second gradiometer signal from the second gradiometer (3, 4) based on a set of formed signal offsets and signal gains, wherein the first gradiometer signal and the second gradiometer signal each comprise measurement information corresponding to the set of magnetic field components; linearly combining the normalized first gradiometer signal and the normalized second gradiometer signal to obtain a normalized gradiometer signal; and Determining the angular position based on the normalized gradiometer signal. [8] The magnetic sensor arrangement according to any one of claims 1 to 7, wherein at least one of the first sensing element (1) or the second sensing element (2) and at least one of the third sensing element (3) or the fourth sensing element (4) are located a greater distance from the center of the axis of rotation than a distance between a circumference of the magnet and the center of the axis of rotation. [9] The magnetic sensor arrangement according to any one of claims 1 to 8, wherein the first sensing element (1), the second sensing element (2), the third sensing element (3) and the fourth sensing element (4) comprise magnetoresistive sensing elements. [10] The magnetic sensor arrangement according to any one of claims 1 to 9, wherein the magnetic sensor (220) is contained in a single semiconductor substrate. [11] The magnetic sensor arrangement according to any one of claims 1 to 10, wherein the magnet is positioned at one end of the rotatable object (205) and the magnetic sensor (220) is positioned axially at a distance from the magnet such that there is an air gap between the magnet and the magnetic sensor (220). [12] A magnetic sensor (220) having the following features: a first gradiometer (1, 2) aligned along a first axis, wherein the first gradiometer (1, 2) has a first gradiometer center on the first axis; wherein the first gradiometer (1,2) comprises a first detection element (1) and a second detection element (2), a second gradiometer (3,4) aligned along a second axis, wherein the second gradiometer (3, 4) comprises a third detection element (3) and a fourth detection element (4), wherein the second gradiometer (3,4) has a second gradiometer center on the second axis, wherein the first axis and the second axis are perpendicular to a center of a rotation axis of a rotatable object (205), wherein the first axis and the second axis intersect at a gradiometer interface that is offset from the first gradiometer center and / or the second gradiometer center, wherein the gradiometer interface is located between the first sensing element (1) and the second sensing element (2) and between the third sensing element (3) and the fourth sensing element (4), and where the first axis and the second axis are not collinear, not orthogonal, and not parallel to each other, wherein the first sensing element (1), the second sensing element (2), the third sensing element (3) and the fourth sensing element (4) are configured to detect a set of magnetic field components perpendicular to the center of the axis of rotation, wherein the set of magnetic field components is measured from a magnetic field generated by a magnet configured to rotate together with the rotatable object (205); and a digital signal processor (330) for Determine, based on the set of magnetic field components, an angular position of the rotatable object (205). [13] The magnetic sensor (220) according to claim 12, wherein the first sensing element (1) and the second sensing element (2) are symmetrical to the third sensing element (3) and the fourth sensing element (4) relative to a radial axis passing through the gradiometer interface and the center of the axis of rotation. [14] The magnetic sensor (220) according to one of claims 12 or 13, wherein the digital signal processor (330) is provided for determining the angular position of the rotatable object (205) to: Normalizing a first gradiometer signal from the first gradiometer (1,2) and a second gradiometer signal from the second gradiometer (3,4) based on a set of formed signal offsets and signal gains, wherein the first gradiometer signal and the second gradiometer signal each comprise measurement information corresponding to the set of magnetic field components; linearly combining the normalized first gradiometer signal and the normalized second gradiometer signal to obtain a normalized gradiometer signal; and Determining the angular position based on the normalized gradiometer signal. [15] The magnetic sensor (220) according to one of claims 12 to 14, wherein the gradiometer interface is aligned with the center of the axis of rotation. [16] The magnetic sensor (220) according to one of claims 12 to 14, wherein the gradiometer interface is offset from the center of the axis of rotation. [17] A procedure comprising the following steps: Rotating a magnet at one end of a rotatable object (205) around the center of a rotational axis, Capture, at a first position and a second position associated with a first gradiometer (1, 2), a first pair of gradiometer signals, and at a third and fourth position associated with a second gradiometer (3, 4), a second pair of gradiometer signals, wherein the first gradiometer (1, 2) comprises a first detection element (1) and a second detection element (2), wherein the second gradiometer (3, 4) comprises a third detection element (3) and a fourth detection element (4), where the first, second, third and fourth positions are offset from the center of the axis of rotation, wherein a first gradiometer center is arranged along a first axis at a midpoint between the first and second positions, and wherein a second gradiometer center is arranged along a second axis at a midpoint between the third and fourth positions, where the first axis and the second axis are each perpendicular to the axis of rotation, wherein the first gradiometer center is offset from the center of the axis of rotation and the second gradiometer center is offset from the center of the axis of rotation; wherein the first axis and the second axis intersect at a gradiometer interface that is offset from the first gradiometer center or the second gradiometer center, wherein the gradiometer interface is located between the first sensing element (1) and the second sensing element (2) and between the third sensing element (3) and the fourth sensing element (4), and where the first axis and the second axis are not collinear, not orthogonal, and not parallel to each other, and Calculating a rotation angle based on the first pair of gradiometer signals and the second pair of gradiometer signals. [18] The method according to claim 17, further comprising: Positioning a magnetic sensor (220) encompassing the first gradiometer (1, 2) and the second gradiometer (3, 4) such that the gradiometer interface is offset from the center of the axis of rotation. [19] The method according to claim 18, wherein the method further comprises positioning the gradiometer interface such that it is offset from the center of the axis of rotation. [20] The method according to one of claims 18 or 19, further comprising: Normalizing the first pair of gradiometer signals and the second pair of gradiometer signals to generate normalized gradiometer signals, and including calculating the rotation angle: Calculating the angle of rotation based on normalized gradiometer signals.

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