Multidimensional measurement using magnetic sensors and related systems, methods and integrated circuits

Abstract

System for detecting the position of a magnetic target, wherein the system comprises the following: An array of magnetic sensor ICs (ICs - Integrated Circuits), wherein a first magnetic sensor IC of the array comprises at least three first magnetic sensing elements and one or more first output contacts configured to provide first information indicating a three-dimensional (3D) position of the magnetic target, wherein the at least three first magnetic sensing elements comprise two magnetic sensing elements positioned in a first substrate plane and another magnetic sensing element positioned in a second substrate plane, the second substrate plane being oriented at a non-zero angle with respect to the first substrate plane, and wherein a second magnetic sensor IC of the array comprises at least three second magnetic sensing elements and one or more second output contacts configured to provide second information indicating the 3D position of the magnetic target.are configured; and , a computing circuit configured to output 3D position information of a magnetic target positioned near the array based on the first information and the second information, wherein the first magnetic sensing elements include an additional magnetic sensing element positioned in the second substrate layer.

Description

AREA OF REVELATION

[0001] The present disclosure relates to detecting a position of a magnetic target. BACKGROUND

[0002] Various arrangements of magnetic sensors are used to measure the position of a magnet. For example, magnetic sensors can be arranged to determine a magnet's position in one, two, or three dimensions. Examples of magnetic sensors include magnetoresistive sensors and Hall sensors.

[0003] US 2016 / 0 161 288 A1 relates to an apparatus and method for estimating the position of a movable stage. The apparatus comprises: a stator comprising a 2D array of sensors arranged relative to each other to provide a plurality of stator Y-oriented sensor columns and a plurality of stator X-oriented sensor rows; a movable stage comprising a first Y-magnet array comprising a plurality of first magnetization segments elongated generally linearly in a step Y direction, each first magnetization segment having a step Y direction length, Lyy, and a magnetization direction generally orthogonal to the step Y direction, the magnetization directions of the plurality of first magnetization segments having a first magnetic spatial period over λx and a step X direction width, Wyx, of the first magnet array;and a controller connected to receive information based on an output from each of the sensors and configured to use the information to determine a stator X-direction position of the movable stage;

[0004] US 2011 / 0 074 406 A1 concerns CMOS-compatible magnetoelectronic field sensors for detecting magnetic fields in three orthogonal directions.

[0005] US 2002 / 0 077 752 A1 relates to a system for detecting the position of one part relative to another without contact between the two parts. For example, one of the parts may be a "target device" that is movable relative to a "detecting device," and the two parts may be incorporated into or mounted on adjacent, relatively movable components of a mechanical system.

[0006] US 2013 / 0 249 542 A1 relates to a foldable substrate comprising a first substrate portion having a first upper surface and a second substrate portion having a second upper surface. A foldable bridge portion couples the first substrate portion to the second substrate portion. The foldable bridge portion includes a coupling strip extending from the first substrate portion to the second substrate portion, with a gap corresponding to a portion of the coupling strip, wherein the gap between the first and second substrate portions is defined by removing portions of a starting wafer substrate. In one embodiment, the first and second portions include magnetic field sensors, and the foldable bridge portion can be bent to position the two portions at a predetermined angle to each other.After bending, the sensor package can be incorporated into a magnetic field sensor assembly to be integrated with other control circuits.

[0007] US 6 052 610 A relates to a method, apparatus and system for tracking an object within a volume, comprising coupling a rotating magnetic dipole to the object, measuring the magnetic fields either remotely, on the surface or outside the volume to generate measurements; and based on the measurements, determining the position and orientation of the magnetic dipole to thereby determine a position and orientation of the object.

[0008] US 2015 / 0 285 611 A1 relates to an object tracking system comprising a sensor grid with a plurality of sensor clusters configured to detect the presence of a magnetic field of an object. Each sensor cluster comprises three or more single-axis magnetic sensors. The sensors in a cluster may be arranged so that their axes are parallel to each other. The sensor grid may account for ambient magnetic noise by measuring the magnetic field in an area remote from the object to update the ambient magnetic noise measurement. The sensor grid, or a portion thereof, may include a plurality of sensors printed on a common sheet. The sensor grid may consist of one or more sheets that overlap or are bonded together.The system can track an object and determine up to three degrees of positioning and three degrees of orientation by using a geometric solution of the intersection points of the magnetic field strengths obtained from the information collected by the magnetic sensors. SUMMARY OF REVELATION

[0009] The present disclosure describes, among other things, embodiments of devices, systems, and methods for using magnetic sensors (e.g., three-dimensional field and / or angle sensors) to monitor the position of a magnetic target. By using a three-dimensional (3D) field or angle sensor, a two-dimensional (2D) array of sensors can be used instead of a three-dimensional array of sensors. Thus, the 3D position of a magnetic target can be measured using fewer sensors in a 2D array compared to a 3D array.

[0010] In one aspect, the present disclosure provides a magnetic sensor for detecting a position of a magnetic target having the features of claim 12.

[0011] The magnetic sensor may further include a processing circuit configured to receive data from the first, second, and third magnetic sensing elements and calculate an angle of a magnetic field based on the received data. The magnetic sensor may also include a fourth magnetic sensing element positioned in the second substrate plane. The magnetic sensing elements may include at least one of an anisotropic magnetoresistive (AMR) sensing element, a giant magnetoresistive (GMR) sensing element, or a tunneling magnetoresistive (TMR) sensing element. The first magnetic sensing element may include magnetoresistive elements arranged in a bridge configuration.In the magnetic sensor, the first substrate plane may be substantially orthogonal to the second substrate plane.

[0012] In another aspect, the present disclosure provides a system for detecting the position of a magnetic target having the features of claim 1.

[0013] The first magnetic sensing elements may comprise two magnetic sensing elements positioned in a first substrate plane and another magnetic sensing element positioned in a second substrate plane, wherein the second substrate plane is oriented at a non-zero angle with respect to the first substrate plane. The first magnetic sensing elements may be anisotropic magnetoresistive sensing elements. The system may determine an angle of the magnetic target. The system may be configured in a non-symmetrical array, a rectangular array, and / or a triangular array. The maximum distance between two IC sensors of the IC sensors may be smaller than the dimensions of the magnetic target in a plane substantially parallel to the two-dimensional array.The computing circuit may be a microcontroller, wherein the computing circuit is configured to determine a coarse position for determining a group of magnetic sensor ICs of the array for use for fine position measurement, the group comprising the first magnetic sensor IC and the second magnetic sensor IC, and wherein the 3D position information comprises the fine position measurement. The computing circuit may determine a three-dimensional rotation of the magnetic target. The computing circuit may output information of a three-dimensional rotation of the magnetic target. A column of magnetic sensor ICs of the array may include magnetic sensor ICs that are unevenly spaced from adjacent magnetic sensor ICs in the column. A maximum distance between two ICs that are closest to each other may be smaller than a largest dimension of the magnetic target. The computing circuit may comprise a microcontroller.The computing circuit may further include an analog-to-digital converter coupled between the magnetic sensor ICs of the array and the microcontroller.

[0014] In another aspect, the present disclosure provides a method for determining a position of a magnetic target having the features of claim 10.

[0015] Magnetic sensors of the array may each comprise two magnetic sensing elements in a first substrate plane and a third magnetic sensing element in a second substrate plane approximately orthogonal to the first substrate plane. Furthermore, the method may comprise measuring an updated rotation of the magnetic target and determining an updated fine position of the magnetic target. The fine position may be a three-dimensional position, and measuring the rotation may comprise measuring the rotation of the magnetic target in three dimensions.

[0016] In another aspect, the present disclosure provides a method of using an integrated circuit (IC) sensor to detect the position of a magnetic target, the method comprising: detecting first magnetic field information at a first magnetic sensing element; detecting second magnetic field information at a second magnetic sensing element, the first and second magnetic sensing elements positioned in a first substrate plane; detecting third magnetic field information at a third magnetic sensing element positioned in a second substrate plane oriented at a non-zero angle with respect to the first substrate plane; and providing the first, second, and third magnetic field information indicative of a three-dimensional (3D) position of the magnetic target at one or more output contacts.

[0017] The method may further comprise processing data from the magnetic sensing element to calculate an angle of a magnetic field associated with the magnetic target. The magnetic sensing elements may comprise an anisotropic magnetoresistive (AMR) sensing element, a giant magnetoresistive (GMR) sensing element, or a tunneling magnetoresistive (TMR) sensing element. The magnetic sensing element may also be arranged in a bridge configuration. The method may comprise determining an angle of the magnetic target.

[0018] For the purpose of summarizing the disclosure, certain aspects, advantages, and novel features of the innovations have been described herein. It should be understood that not all such advantages may necessarily be achieved according to each specific embodiment. Thus, the innovations may be designed or practiced in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] These drawings and the related description herein are provided to illustrate certain embodiments of the invention and are not intended to be limiting. Fig. Figure 1 is a diagram of magnetic sensors that detect magnetic fields and angles. Fig. 2 is a perspective view of a 3D magnetic sensor according to an embodiment of the present disclosure. Fig. 3 is a perspective view of a 3D magnetic sensor according to an embodiment of the present disclosure. Fig. 4 is a schematic diagram of a 3D sensor according to an embodiment of the present disclosure. Fig. 5 is a schematic diagram of a 3D sensor according to an embodiment of the present disclosure. Fig. 6 is a perspective view of an exemplary magnetic target. Fig. 7 is a perspective view of a magnetic target and a sensor array according to an embodiment of the present disclosure. Fig. 8A is a top view of a sensor array according to an embodiment of the present disclosure. Fig. 8B is a top view of a sensor array according to an embodiment of the present disclosure. Fig. 8C is a top view of a sensor array according to an embodiment of the present disclosure. Fig. 8D is a top view of a sensor array according to an embodiment of the present disclosure. Fig. 8E is a top view of a sensor array according to an embodiment of the present disclosure. Fig. 8F is a top view of a sensor array according to an embodiment of the present disclosure. Fig. 9 is a schematic diagram of a sensor array and a microcontroller according to an embodiment of the present disclosure. Fig. 10 is a schematic diagram of a sensor array, an analog-to-digital converter, and a microcontroller according to an embodiment of the present disclosure. Fig. 11A is a perspective view of a 3D sensor including Hall sensors with a soft magnetic part according to an embodiment of the present disclosure. Fig. 11B is a side view of the 3D sensor of Fig. 12 with a homogeneous magnetic field influenced by the soft magnetic part. Fig. 12 is a flowchart of a 3D position determination process according to an embodiment of the present disclosure. Fig. 13A is a plan view of a sensor array and a magnetic target illustrating the determination of a coarse position according to the method of Fig. 12 represents. Fig. 13B is a plan view of a sensor array and a magnetic target illustrating the determination of a coarse position according to the method of Fig. 12 when the magnetic target is in a position other than Fig. 13A is located. Fig. Figure 14A is a plan view of a sub-array of sensors and the magnetic target corresponding to the determination of field rotation measurement in the process of Fig. 12. Fig. Figure 14B is a plan view of various sub-arrays of sensors and the magnetic target corresponding to the determination of field rotation measurement in the process of Fig. 12, if the magnetic target is in a position other than Fig. 14A is located. Fig. 15 is a flowchart of a 3D position determination process according to an embodiment of the present disclosure. Fig. 16 is a flowchart of a 3D position determination process according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0020] Various aspects of the novel systems, devices, and methods are described in more detail below with reference to the accompanying drawings. However, aspects of the present disclosure may be embodied in many different forms and should not be construed as limited to any specific structure or function presented anywhere in this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Based on the teachings contained herein, it will be understood by those skilled in the art that the scope of the disclosure is intended to cover every aspect of the novel systems, devices, and methods disclosed herein, whether implemented independently or in combination with any other aspect.For example, an apparatus may be implemented or a method performed using any number of the aspects set forth herein. Furthermore, the scope of protection is intended to cover such an apparatus or method implemented using a different structure, functionality, or structure and functionality in addition to or different from the various aspects set forth herein. It is understood that each aspect disclosed herein may be embodied by one or more elements of a claim.

[0021] Although specific aspects are described herein, many variations and permutations of those aspects are within the scope of the disclosure. While some benefits and advantages of the preferred aspects are noted, the scope of the disclosure is not intended to be limited to any particular benefits, uses, or objectives. Rather, the aspects of the disclosure are intended to be generally applicable to a wide variety of systems. The detailed description and drawings merely illustrate the disclosure and do not limit it, with the scope of the disclosure being defined by any appended claims and their equivalents.

[0022] In the following description, reference is made to the drawings, in which like reference numerals may indicate identical or functionally similar parts. It is understood that elements shown in the figures are not necessarily drawn to scale. Further, it is understood that certain embodiments may include more elements than shown in any one drawing and / or a subset of the elements shown in a drawing. Furthermore, some embodiments may include any suitable combination of features from two or more drawings. Headings are included herein for convenience only and do not necessarily affect the scope or meaning of the claims.

[0023] Aspects of the present disclosure relate to detecting a three-dimensional (3D) position and / or angle of a magnetic target. Such detection can be implemented using magnetic field and / or angle sensors. A 3D magnetic field sensor can include at least three magnetic sensing elements. For example, a 3D magnetic field sensor can include Hall sensors arranged in 3 dimensions or a monolithic integrated component using a soft magnetic element. With such a sensor, it is possible to calculate a field angle of a magnetic field (elevation and azimuth) using the arctangent (arctan or artan) function.Similar calculations can be performed in conjunction with a 3D angle sensor containing anisotropic magnetoresistive (AMR) sensing elements, giant magnetoresistive (GMR) sensing elements, tunneling magnetoresistive (TMR) sensing elements, or any combination thereof. Magnetoresistive sensors can provide signals with amplitudes that are less affected by magnetic field strength than Hall sensors.

[0024] The magnetic sensing discussed herein can be implemented, for example, in industrial automation applications. For example, the 3D position sensing discussed herein can be implemented in production lines with parts moving in three dimensions. 3D magnetic sensors

[0025] Fig. Figure 1 is a diagram of magnetic sensors that detect magnetic fields. Fig. 1 shows a magnetic target 110 that generates magnetic fields 120. In Fig. 1, magnetic sensors 130A and 130B are arranged to measure an angle of the emitted magnetic fields 120. Outputs of the magnetic sensors 130A and 130B can be used to determine a 3D position of the magnetic target 110. The position of the magnetic target 110 can be detected based on the magnetic target generating unique field angles around the magnetic target. Fig. 1 shows an angle change near the magnetic target 110.

[0026] Fig. Figure 2 is a perspective view of a 3D magnetic sensor 200 according to an embodiment of the present disclosure. The 3D magnetic sensor 200 includes a first substrate 210 and a second substrate 250. Magnetic sensing elements 220A and 220B are disposed on the first substrate 210. The magnetic sensing elements 220A and 220B can measure the sine and cosine magnetic field signals, respectively. A magnetic sensing element 260 is disposed on the second substrate 250 and is configured to measure the magnetic field signals along a third axis. Each of the magnetic sensing elements 220A, 220B, and 260 can include a full bridge, as shown. As shown, the magnetic sensing elements 220A and 220B can be oriented at an angle of approximately 45° with respect to each other. The magnetic sensing elements 220A, 220B, and 260 may each be magnetoresistive sensing elements, such as any suitable magnetoresistive (xMR) sensing element.Example xMR sensing elements include a giant magnetoresistive (GMR) sensing element, a tunneling magnetoresistive (TMR) sensing element, and an AMR sensing element. Magnetic sensing elements 220A, 220B, and 260 may be arranged to detect a magnetic field in three dimensions. The second substrate 250 is oriented at a non-zero angle relative to the first substrate 210. The first substrate 210 and the second substrate 240 may be approximately orthogonal to each other, as shown in FIG. Fig. 2 shown.

[0027] Fig. 3 is a perspective view of a 3D magnetic sensor 300 according to an embodiment of the present disclosure. The 3D magnetic sensor 300 includes one more magnetic sensing element than the 3D magnetic sensor 200 of Fig. 2. The 3D magnetic sensor 300 includes a first substrate 310 and a second substrate 350. Magnetic sensing elements 320A and 320B are arranged on the first substrate 310. The magnetic sensing elements 310A and 310B can measure the sine and cosine magnetic field signals, respectively. Magnetic sensing elements 360A and 360B are arranged on the second substrate 350 and can measure magnetic field signals along a third axis. The second substrate 350 is positioned at a non-zero angle relative to the first substrate 310. The first substrate 310 and the second substrate 350 can be approximately orthogonal to each other, as shown in Fig. 3. The magnetic sensing elements 320A, 320B, 360A, and 360B may be magnetic angle sensors. For example, these sensors may be AMR sensors.

[0028] Fig. Figure 4 is a schematic diagram of a 3D magnetic sensor 400 according to an embodiment of the present disclosure. The 3D magnetic sensor 400 includes magnetic sensing elements 410A, 410B, and 410C. The magnetic sensing elements 410A, 410B, and 410C may be similar to the magnetic sensing elements 220A, 220B, and 260, respectively, of Fig. 2. For example, the physical layouts of the magnetic sensing elements 410A, 410B and 410C may be as shown in the diagram of Fig. 2 are aligned with each other. Each magnetic sensing element may comprise a full bridge, as shown in Fig. 4. The magnetic sensing elements 410A, 410B, and 410C are coupled to a processing circuit 420. The processing circuit 420 is configured to receive data from the magnetic sensing elements 410A, 410B, and 410C. The processing circuit 420 may process outputs of the magnetic sensing elements 410A, 410B, and 410C. For example, the processing circuit 420 may calculate a magnitude of a magnetic field associated with a magnetic target. The processing circuit 420 may be included in the same integrated circuit as the magnetic sensing elements 410A, 410B, and 410C. The processing circuit 420 may receive information indicative of the detected magnetic field of the magnetic target and use the information to calculate a field angle of a magnetic field (elevation and azimuth) using the arctangent (arctan or artan) function.A two-argument arctangent function may be referred to as an atan2 function. In certain embodiments, an output signal of processing circuitry 420 is an analog signal (e.g., an amplified signal from each magnetic sensing element 410A, 410B, and 410C). In some other embodiments, the output signal is a digital angle signal representing pairs of arctangent functions of sensing element outputs (e.g., atan2(output of magnetic sensing element 410A, output of magnetic sensing element 410B) and atan2(output of magnetic sensing element 410B, output of magnetic sensing element 410C)). One or more outputs of processing circuitry 420 may be provided to a microcontroller for determining a 3D position of a magnetic target.In some other embodiments, outputs of one or more magnetic sensing elements may be provided to a microcontroller without further processing on the IC containing the magnetic sensing elements. Any other suitable computational circuitry may be used instead of, or in combination with, any of the microcontrollers discussed herein. For example, an application-specific integrated circuit (ASIC) may compute position information for a magnetic target instead of, or in conjunction with, a microcontroller.

[0029] Fig. 5 is a schematic diagram of a 3D magnetic sensor 500 according to an embodiment of the present disclosure. The 3D magnetic sensor 500 includes magnetic sensing elements 510A, 510B, 510C, and 510D. In an AMR-based sensor, the magnetic sensing elements 510A, 510B, 510C, and 510D may be implemented as full bridges. Two pairs of full bridges may be implemented for AMR-based sensors. AMR sensors may detect an angle of a magnetic field. One bridge of each pair may be oriented at a non-zero angle (e.g., a 45-degree angle) with respect to the other bridge of the pair.

[0030] The magnetic sensing elements 510A, 510B, 510C and 510D can be assigned to the magnetic sensing elements 310A, 310B, 330A and 330B, respectively, of Fig. 3. Each magnetic sensing element may contain a full bridge, as shown in Fig. 5. The magnetic sensing elements 510A, 510B, 510C, and 510D are coupled to a processing circuit 520. The processing circuit 520 processes data from the magnetic sensing elements 510A, 510B, 510C, and 510D. For example, the processing circuit 520 may calculate an angle of a magnetic field. The processing circuit 520 may be included in the same integrated circuit as the magnetic sensing elements 510A, 510B, 510C, and 510D. One or more outputs of the processing circuit 520 may be provided to a microcontroller or other computational circuitry for determining a 3D position of a magnetic target. In certain embodiments, an output signal of the processing circuit 520 is an analog signal (e.g., an amplified signal of each magnetic sensing element 510A, 510B, 510C, and 510D).In some other embodiments, the output signal is a digital angle signal representing pairs of arctangent functions of sensing element outputs (e.g., atan2(output of magnetic sensing element 510A, output of magnetic sensing element 510B) and atan2(output of magnetic sensing element 510C, output of magnetic sensing element 510D)). In certain embodiments, outputs of one or more magnetic sensing elements may be provided to a microcontroller or other computing circuitry without further processing on the IC containing the magnetic sensing elements.

[0031] The magnetic field angular distribution around a bar magnet can be unique but symmetrical about the bar magnet. Accordingly, a rotation of the bar magnet around its axis, pointing from the north to the south pole of the bar magnet at 180 degrees, should produce the same field angular distribution. In the case of a square magnet, a 90-degree rotation should produce the same field angular distribution as before the 90-degree rotation. A non-symmetric magnetic target can produce a field distribution that is unique across the entire angular spectrum, even after rotation. Accordingly, it is possible to calculate the absolute position, including all angles in any physical position, for a non-symmetric magnetic target. Furthermore, the distribution of magnetic field angles of a non-symmetric magnetic target should be unique and predictable.Thus, it is possible to detect both the position of such a magnetic target in the x-, y-, and z-axes, as well as the rotation around all three axes, based on comparing the detected field angles with the predicted field angle distribution. Accordingly, it may be advantageous to use a non-symmetric magnetic target with the magnetic sensor arrays discussed herein. An example of such a non-symmetric magnetic target is described with reference to [FIG. 1]. Fig. 6 described.

[0032] Fig. 6 is a perspective view of an exemplary magnetic target 600. The magnetic target 600 includes a plurality of magnets 610A, 610B, 610C, and 610D. The magnetic target 600 can generate magnetic field angles that are unique around the magnetic target 600. Magnetic sensors discussed herein can detect a 3D position of a magnetic target that includes two or more magnets, such as the magnetic target 600. Magnetic sensors discussed herein can also detect a 3D position of a magnetic target that includes a single magnet.

[0033] Magnetic sensor ICs discussed herein may be arranged in 2D arrays. Such arrays may be used to determine a 3D position of a magnetic target. Any of the magnetic sensor IC arrays discussed herein may include any suitable number of magnetic sensor ICs. For example, hundreds or thousands of such magnetic sensor ICs may be included in a 2D array. Example magnetic sensor IC arrays are discussed. However, any suitable arrangement of magnetic sensor ICs may be implemented to determine the 3D position of a magnetic target.

[0034] Fig. Figure 7 is a perspective view of a magnetic target 600 as shown in Fig. 6, and a 2D sensor array 700 according to an embodiment of the disclosure. The 2D sensor array 700 can be used to detect the field angle in several different positions. The magnetic target 600 can include a plurality of magnets 610A, 610B, 610C, and 610D. The sensor array 700 includes 3D magnetic sensor ICs including magnetic sensor ICs 710A, 710B, and 710C. As illustrated, the sensor array 700 includes a plurality of additional sensor ICs than the magnetic sensor ICs 710A, 710B, and 710C. Each of the 3D magnetic sensor ICs can be configured according to any suitable principles and advantages described with reference to the Fig. 2 to 5. For example, each of the 3D magnetic sensor ICs 710A, 710B, and 710C can implement the 3D magnetic sensor of Fig. 2, the 3D magnetic sensor from Fig. 3, the 3D magnetic sensor from Fig. 4 or the 3D magnetic sensor from Fig. 5 or any suitable combination of features of these 3D magnetic sensors. The field angle distribution should be unique for the magnetic target 600. Detection of the field angles can provide information about the field angles at different locations, and the position of the magnetic target 600 can be determined from such information.

[0035] In some cases, measuring a magnetic field angle rather than a magnetic field magnitude associated with a magnetic target may be desirable. The magnetic field strength (e.g., magnitude) around a magnetic target can change significantly with variations in the temperature of the magnetic target. This may be due to the temperature coefficient of magnetic remanence and coercivity. In comparison, the magnetic field angle may remain essentially constant over a given temperature range. By measuring the magnetic field angle rather than the magnetic field magnitude, the effect of temperature on a magnetic target position measurement can be reduced. Furthermore, the magnetic field angle distribution of specific magnetic targets should be unique and predictable.Thus, it is possible to detect both the position of such a magnetic target in x-, y- and z-axes as well as the rotation around all three axes using an array of 3D magnetic position sensor ICs based on the comparison of the detected field angles with the predicted distribution of the field angles. Magnetic sensor IC arrays

[0036] Magnetic sensor ICs can be arranged in an array in a variety of ways. Some example magnetic sensor IC arrays are described. Any suitable principles and advantages of these sensor arrays can be implemented in combination with one another.

[0037] Fig. Figure 8A is a top view of a sensor array 800 according to an embodiment of the present disclosure. The sensor array 800 includes the magnetic sensor ICs 710A, 710B, and 710C and several additional sensors, as shown in Fig. 8A. Each of the magnetic sensors of the sensor array 800 may be implemented by a separate IC according to any suitable principles and advantages of Fig. 2 to 5 are implemented. As in Fig. 8A, the magnetic sensors are configured in a rectangular (e.g., a square) arrangement. The sensor array 800 includes magnetic sensors arranged in rows and columns. The illustrated magnetic sensors are evenly spaced apart in rows and columns. The maximum distance between two magnetic sensors that are closest to each other in the same column or row may be shorter than the dimensions of a magnetic target detected by the sensor array 800. In particular, for the magnetic target 600 of Fig. 6, the maximum distance between two magnetic sensors closest to each other in the same column or row may be less than the larger of the x- or y-dimensions of the magnetic target 600. In some embodiments, three adjacent sensors in the sensor array 800 are configured in a triangular arrangement (for example, magnetic sensors 710A, 710B, and 710C). The three-sensor arrangement provides magnetic field and rotation measurements for calculating the position of a magnetic target, as described below. The distance between each group of two sensors in the sensor array 900 may be less than the dimensions of a magnetic target sensed by the sensor array 800.

[0038] Fig. 8B is a top view of a reduced sensor array 810 according to an embodiment of the present disclosure. The reduced sensor array 810 includes, compared to the rectangular sensor array 800 of Fig. 8A fewer magnetic sensors. With a reduced sensor array, accurate position and / or field angle measurements can be obtained with fewer magnetic sensors than with the 800 magnetic sensor array from Fig. 8A. The sensor array 810 includes the magnetic sensors 710A, 710B and 710C and several additional sensors, as shown in Fig. 8B. Each of the magnetic sensors of the sensor array 810 may be implemented by a separate IC according to any suitable principles and advantages of Fig. 2 to 5. In this embodiment, the magnetic sensors are configured in a reduced rectangular (e.g., square) arrangement. The illustrated sensor array 810 contains clusters of 4 magnetic sensor ICs. The maximum distance between two magnetic sensors closest to each other in the same column or row may be shorter than the dimensions of a magnetic target sensed by the sensor array 810. In some embodiments, three adjacent sensors in the sensor array 800 are configured in a triangular arrangement (e.g., the magnetic sensors 710A, 710B, and 710C in Fig. 8B). The three-sensor array provides magnetic field and rotation measurements for calculating the position of a magnetic target, for example, as described below. The distance between each group of two sensors in a reduced rectangle of sensor array 810 may be smaller than the dimensions of a magnetic target sensed by sensor array 810.

[0039] The Fig. 8C and Fig. 8D are plan views of other embodiments of reduced sensor arrays 820 and 830, respectively. These reduced sensor arrays contain, in comparison to the regular rectangular sensor array of Fig. 8A fewer magnetic sensors. The illustrated sensor arrays 820 and 830 include the magnetic sensors 710A, 710B, and 710C, respectively, and several additional sensors. Each of the magnetic sensors of the sensor array 820 or 830 may be implemented by a separate IC according to any suitable principles and advantages of the Fig. 2 to 5. The maximum distance between two magnetic sensors closest to each other in the same column or row may be shorter than the dimensions of a magnetic target sensed by sensor array 820 or 830. In some embodiments, three adjacent sensors in sensor array 820 or 830 are configured in a triangular array (e.g., magnetic sensors 710A, 710B, and 710C). The three-sensor array provides magnetic field and rotation measurements for calculating the position of a magnetic target, as described below. The distance between each group of two sensors in sensor array 820 or 830 may be shorter than the dimensions of a magnetic target sensed by sensor array 820 or 830.

[0040] Additional magnetic sensor arrays 840 and 850 are used in the Fig. 8E and 8F, respectively. These magnetic sensor arrays are alternative ways of implementing an array of magnetic sensor ICs according to the principles and advantages discussed herein. The magnetic sensor array 840 of Fig. 8E includes groups of three magnetic sensor ICs configured in a triangular array. The spacing between each group of two sensors in sensor array 840 may be smaller than the dimensions of a magnetic target sensed by sensor array 840. Sensor array 850 shows an alternative arrangement of the magnetic sensor ICs.

[0041] Computing circuitry may be implemented with a magnetic sensor array to process outputs from the magnetic sensor ICs. Such computing circuitry may calculate position and / or field angle. Computing circuitry may include a microcontroller. In some cases, computing circuitry may include an analog-to-digital converter and a microcontroller. Any other suitable computing circuitry may be implemented according to the principles and advantages discussed herein. For example, computing circuitry may include an ASIC. As another example, computing circuitry may include a processor combined with memory.

[0042] Fig. 9 is a schematic diagram of a sensor array 900 and a microcontroller 920 according to one embodiment of the present disclosure. The sensor array 900 includes magnetic sensor ICs, including the magnetic sensor ICs 710A, 710B, and 710C, and additional magnetic sensor ICs as shown. The microcontroller 920 is a computational circuit capable of calculating position and rotation information for a magnetic target. The microcontroller 920 communicates with the magnetic sensor ICs of the sensor array 900. In one embodiment, the microcontroller 920 receives all angle information from all sensors. The microcontroller 920 can then compare the detected distribution of field angles with the known distribution of field angles of the magnetic target to determine a first position.In a subsequent operation, microcontroller 920 may receive signals from a subset of the sensors of sensor array 900 that are close to the magnetic target (e.g., at least three magnetic sensing elements). Using this information, microcontroller 920 may perform the same operation (e.g., comparison with a known field distribution). Depending on the position result, microcontroller 920 may receive different sensor signals from different sensors in another subsequent operation. By performing these operations, microcontroller 920 may output 3D position information of a magnetic target positioned near sensor array 900 based on the outputs of the 3D sensors.

[0043] Fig. Figure 10 is a schematic diagram of a sensor array 1000 with a computing circuit according to an embodiment of the present disclosure. The sensor array 1000 includes magnetic sensor ICs, including the magnetic sensor ICs 710A, 710B, and 710C, and additional magnetic sensor ICs, as shown. Fig. 10, the computing circuit includes an analog-to-digital converter 1030 and a microcontroller 1020. The analog-to-digital converter (ADC) 1030 is connected to the magnetic sensor ICs of the sensor array 1000. The Fig. The embodiment shown in Figure 10 corresponds to the one shown in Fig. 9, except that the ADC 1030 converts analog outputs of the magnetic sensor ICs into digital signals for the microcontroller 1020. In Fig. 10, the analog-to-digital converter 1030 is configured to output digital signals representing 3D position information of a magnetic target positioned near the sensor array 1000 based on the outputs of the magnetic sensor ICs. Other magnetic sensors

[0044] The embodiments discussed above include magnetoresistive sensing elements. Other types of magnetic sensors may be implemented alternatively or additionally. Such sensors may be implemented in arrays according to any suitable principles and advantages discussed herein. An example of a 3D magnetic sensor including Hall sensors will now be described.

[0045] Fig. 11A is a perspective view of a 3D magnetic sensor including Hall sensors and a soft magnetic component arranged according to an embodiment of the present disclosure. The illustrated 3D sensor 1100 includes a soft magnetic component 1110 positioned on a substrate 1120. The 3D sensor 1100 also includes Hall sensors 1160A, 1160B, and 1160C. The 3D sensor 1100 can detect magnetic fields along the x-axis 1130, magnetic fields along the y-axis 1140, and magnetic fields along the z-axis 1150. Using the illustrated 3D sensor 1100, the field angle of a magnetic field (elevation and azimuth) can be calculated using the arctangent (arctan or artan) function.

[0046] Fig. 11B is a side view of the 3D sensor 1100 of Fig. 11A and a homogeneous magnetic field influenced by the soft magnetic component 1110. As shown, the soft magnetic component 1110 bends the magnetic flux 1130. Method for determining the position and rotation of the magnetic target

[0047] Using an array of magnetic sensor ICs according to the principles and advantages discussed herein, a three-dimensional position and three-dimensional rotation of a magnetic target can be determined. Example methods for determining the position and rotation of a magnetic target are discussed. These methods can be performed using magnetic sensors and / or an array of magnetic sensor ICs having one or more features discussed herein. Operations of any methods discussed herein can be performed in any suitable order. Certain operations or any of the methods discussed herein can be performed serially or in parallel, as appropriate.

[0048] Fig. 12 is a flowchart of a process 1200 for determining a position and rotation of a magnetic target according to an embodiment of the present disclosure. The process 1200 includes determining a coarse position at block 1220, measuring a field rotation of a magnetic target at block 1230, and determining a fine position of the magnetic target at block 1240.

[0049] At block 1220, a coarse position of a magnetic target is determined. A magnetic sensor, such as a magnetic sensor of one of the Fig. 2 to 5, can generate an output indicating the magnetic fields or angles associated with the magnetic target. A computational circuit can determine whether a detected magnetic field exceeds a threshold. The computational circuit can be implemented on a magnetic sensor IC, external to the magnetic sensor IC, or partially on a magnetic sensor IC and partially external to the magnetic sensor IC. The computational circuit can determine whether the inequality of Equation 1 is valid. sin(x)2+cos(x)2≥threshold

[0050] In one example, the threshold value might be approximately 8 KA / m. If the magnitude of the detected magnetic field is greater than 8 KA / m, then the detection is valid. However, if the magnitude of the detected magnetic field is less than 8 KA / m, then the detection is invalid. Other values ​​can be used as the threshold.

[0051] The Fig. 13A and Fig. 13B are top views of a sensor array 1300 illustrating the coarse position determination process of block 1220. The Fig. 13A and Fig. 13B illustrate various positions of a magnetic target 1310 and various coarse positions of the magnetic target 1310. For example, the magnetic target 1310 may initially be in the position of Fig. 13A and then move to the position of Fig. 13B. Multiple magnetic sensor ICs may be arranged in an array. The validity determination described above using Equation 1 may be performed for each magnetic sensor IC. The validity determination may be performed by computing circuitry on each magnetic sensor or by computing circuitry associated with the magnetic sensor ICs of the array. Each magnetic sensor IC may be designated as valid (e.g., the shaded magnetic sensor ICs, such as magnetic sensor 1320A) or invalid (e.g., the unshaded magnetic sensor ICs, such as magnetic sensor 1320B). In some embodiments, a microcontroller 920 or 1020 (not shown) may be configured to store an information indication of whether each magnetic sensor IC is valid.From such a microcontroller, a magnetic image containing an image of each valid sensor reflecting a coarse position of the magnetic target 1310 can be output.

[0052] Again on Fig. 12, at block 1230, the magnetic field rotation associated with a magnetic target is detected. The magnetic field rotation can be determined in 3 dimensions. The field rotation information from valid sensors, as determined at block 1220, can be used at block 1230. Information from the invalid sensors, as determined at block 1220, can be ignored for purposes of field rotation determination. The orientation of the magnetic target can be known before measurements are taken. The magnetic target can be asymmetric. Each magnetic sensor IC of the array is an independent sensor that can provide information that represents the rotation about an axis, such as the axis shown in Fig. 14A, or the y-axis. If the magnetic target is rotated, the magnetic sensor ICs can provide information that indicates the field rotation about a rotated axis, such as the axis shown in Fig. 14B, indicate aligned field rotation. The distance the magnetic target moves due to the rotation of the magnetic target in the x-axis and y-axis can be calculated using Equation 2: dist=arctan2(first sensor)−arctan2(second sensor)

[0053] The Fig. 14A and Fig. 14B are top views of sub-arrays of magnetic sensor ICs of the array of the Fig. 13A and Fig. 13B, illustrating the field rotation measurement process of block 1230. Fig. 14A represents the sub-array 1400A of the sensor array 1300 according to the position of the magnetic target 1310 in Fig. 13A. Fig. 14B represents the sub-array 1400B of the sensor array 1300 according to the position of the magnetic target 1310 in Fig. 13B. A subset of magnetic sensor ICs of array 1300 identified as valid at block 1220 may perform the field rotation measurement, for example, according to equation 2. The Fig. 14A and Fig. 14B contain the magnetic sensor IC 1420A and other similarly shaded magnetic sensor ICs that provide information indicating the field rotation around the x-axis. Fig. 14A and Fig. 14B also includes the 1420B magnetic sensor IC and other similarly shaded magnetic sensor ICs that provide information indicating field rotation about the y-axis. Fig. Figure 14B shows the magnetic sensor sub-array 1400B after rotation of the magnetic target. Fig. 14B, magnetic sensor IC 1420A and similarly shaded magnetic sensor ICs provide information indicating field rotation on the x'-axis, and magnetic sensor IC 1420B and similarly shaded magnetic sensor ICs provide information indicating field rotation on the y'-axis.

[0054] Again on Fig. Referring to Figure 12, the fine position associated with the magnetic target may be determined at block 1240. The fine position is determined using Equation 3: position=real_distarctan2(second sensor)−arctan(first sensor)∗arctan2(first sensor)

[0055] In Equation 3, the real_dist value represents a known physical distance between the magnetic sensor ICs, and 'position' can be a fine position measurement in a specific dimension, such as the x-dimension. Using Equation 3, the position of the magnetic target relative to the position of the magnetic sensor IC can be determined.

[0056] The order in which the operations of process 1200 are performed may vary according to certain embodiments. For example, the coarse position determination at block 1220 for the magnetic target may be performed for the x-axis, the y-axis, and then the z-axis. Then, the magnetic field rotation determination may be performed at block 1230 for the x-axis, the y-axis, and then the z-axis. Finally, the fine position determination may be performed at block 1240 for the x-axis, the y-axis, and then the z-axis. Alternatively, the operations at blocks 1220, 1230, and 1240 may be performed to determine the position of the magnetic target in the x-axis, then determine the position of the magnetic target in the y-axis, and then determine the position of the magnetic target in the z-axis.In another example, the various operations of process 1200 may be performed in parallel for position in different dimensions.

[0057] Fig. 15 is a flowchart of a process 1500 for determining a position and rotation of a magnetic target according to one embodiment. The process 1500 is like the process 1200 of Fig. 12, except that unlike process 1200, process 1500 may update measurements. Processes 1200 and 1500 may each include determining a coarse position of a magnetic target at block 1220, measuring a field rotation of the magnetic target at block 1230, and determining a fine position of the magnetic target at block 1240. After performing these operations, process 1500 may measure an updated fine position of the magnetic target at block 1550. The coarse position and / or field rotation determinations may be updated at block 1550 based on the updated fine position determination.

[0058] Fig. 16 is a flowchart of a process 1600 for determining the position and rotation of a magnetic target according to one embodiment. The process 1600 is like the process 1500 of Fig.15, except that operations may be performed in a different order and measurements may be updated differently. In process 1600, the fine position determination may be performed at block 1240 before measuring the field rotation at block 1230. Process 1600 may measure an updated field rotation at block 1650. The coarse position and / or fine position determination may be updated based on the updated fine field rotation at block 1650. Applications and terminology

[0059] Aspects of the present disclosure may be implemented in various electronic devices. Examples of the electronic devices may include, but are not limited to, consumer electronic products, parts of the consumer electronic products, electronic test equipment, industrial electronic devices, vehicle electronic systems, etc. Examples of the electronic devices may include, but are not limited to, computing devices, production line electronics, communication devices, electronic household appliances, automotive electronic systems, etc. Furthermore, the electronic devices may include unfinished products.

[0060] Unless the context clearly requires otherwise, the terms "comprise," "comprising," "include," "containing," and the like throughout the specification and claims are to be construed as inclusive, as opposed to exclusive or exhaustive; that is, as including, but not limited to. Furthermore, the terms "herein," "above," "hereinafter," and terms of similar import, as used in this application, are to be understood as referring to this application as a whole and not to any specific portions of the present application. Where the context permits, terms used in the singular or plural in the "Detailed Description" section above may also include the plural or singular, respectively.Where the context permits, the expression "or" with respect to a list of two or more elements is intended to cover all of the following interpretations of the expression: any element of the list, all elements of the list, and any combination of elements of the list.

[0061] Furthermore, conditional language used herein, including, but not limited to, "may," "could," "might," "may," "e.g.," "for example," "such as," and the like, unless specifically stated otherwise or understood otherwise in the context used, is generally intended to convey that certain embodiments include certain features, elements, and / or conditions, while other embodiments do not. Thus, such conditional language is generally not intended to imply that features, elements, and / or conditions are in any way required of one or more embodiments, or that one or more embodiments necessarily include logic for deciding, with or without input or prompting from the author, whether these features, elements, and / or conditions are included or should be performed in any particular embodiment.

[0062] The foregoing description and claims may refer to elements or features as being "connected" or "coupled" to one another. As used herein, unless expressly stated otherwise, "connected" means that one element / feature is directly or indirectly connected to another element / feature and not necessarily mechanically. Likewise, unless expressly stated otherwise, "coupled" means that one element / feature is directly or indirectly connected to another element / feature and not necessarily mechanically. Thus, although the various schematic representations shown in the figures depict example arrangements of elements and components, additional intervening elements, devices, features, or components may be present in an actual embodiment (assuming that the functionality of the circuits shown is not adversely affected).

[0063] As used herein, the term "determining" encompasses a wide variety of acts. For example, "determining" may include computationally solving, calculating, processing, deriving, examining, looking up (e.g., looking up in a spreadsheet, database, or other data structure), determining, and the like. "Determining" may further include receiving (e.g., receiving information), accessing (e.g., accessing data in memory), and the like. "Determining" may further include solving, selecting, choosing, creating, and the like. Furthermore, a "channel width," as used herein, may, in certain aspects, include or be referred to as a bandwidth.

[0064] The various operations of the methods described above may be performed by any suitable means capable of performing the operations, such as one or more different hardware and / or software components, circuits, and / or one or more modules. In general, any operations depicted in the figures may be performed by corresponding functional means capable of performing the operations.

[0065] The various illustrative logic blocks, modules, and circuits described in connection with the present disclosure may be implemented or embodied with a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in alternatives, the processor may be any commercially available processor, controller, microcontroller, or state machine.A processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0066] The methods disclosed herein comprise one or more operations or acts for achieving the described method. The method operations and / or acts may be interchanged as appropriate without departing from the scope of the disclosure. In other words, the order and / or use of specific operations and / or acts may be modified without departing from the scope of the disclosure, unless a specific order of steps or acts is indicated.

[0067] It should be understood that the implementations are not limited to the precise configuration and components shown above. Various modifications, changes, and variations may be made in the arrangement, operation, and details of the methods and apparatus described above without departing from the scope of the implementations.

[0068] Although the present disclosure has been described with reference to specific embodiments, other embodiments that would be apparent to one of ordinary skill in the art, including embodiments that do not provide all of the features and advantages recited herein, are also within the scope of the present disclosure. Furthermore, the various embodiments described above may be combined to provide additional embodiments. Furthermore, certain features shown in connection with one embodiment may also be incorporated into other embodiments.

Claims

[1] A system for detecting the position of a magnetic target, the system comprising: an array of magnetic sensor ICs (ICs - Integrated Circuits), wherein a first magnetic sensor IC of the array comprises at least three first magnetic sensing elements and one or more first output contacts configured to provide first information indicative of a three-dimensional (3D) position of the magnetic target, wherein the at least three first magnetic sensing elements comprise two magnetic sensing elements positioned in a first substrate plane and another magnetic sensing element positioned in a second substrate plane, wherein the second substrate plane is oriented at a non-zero angle with respect to the first substrate plane, and wherein a second magnetic sensor IC of the array comprises at least three second magnetic sensing elements and one or more second output contacts configured to provide second information indicative of the 3D position of the magnetic target,are configured; and, a computing circuit configured to output 3D position information of a magnetic target positioned proximate the array based on the first information and the second information, and wherein the first magnetic sensing elements comprise an additional magnetic sensing element positioned in the second substrate plane. [2] The system of claim 1, wherein the first magnetic sensing elements are anisotropic magnetoresistive sensing elements. [3] The system of any preceding claim, wherein the coarse position determination computing circuit is configured to determine a group of magnetic sensor ICs of the array for use in a fine position measurement, the group comprising the first magnetic sensor IC and the second magnetic sensor IC, and wherein the 3D position information comprises the fine position measurement. [4] The system of claim 3, wherein the computing circuit is configured to determine information of a three-dimensional rotation of the magnetic target. [5] A system according to any preceding claim, wherein the computing circuit is configured to output information of a three-dimensional rotation of the magnetic target. [6] The system of any preceding claim, wherein a column of magnetic sensor ICs of the array includes magnetic sensor ICs that are unevenly spaced from adjacent magnetic sensor ICs in the column. [7] The system of any preceding claim, wherein a maximum distance between two ICs adjacent to the magnetic sensor ICs of the array that are closest to each other is smaller than a largest dimension of the magnetic target. [8] A system according to any preceding claim, wherein the computing circuit comprises a microcontroller. [9] The system of claim 8, wherein the computing circuitry further comprises an analog-to-digital converter coupled between the magnetic sensor ICs of the array and the microcontroller. [10] A method for determining a position of a magnetic target, the method comprising: Identifying a group of magnetic sensors of an array of magnetic sensors that generate a respective signal corresponding to a threshold value to determine a coarse position of the magnetic target; Measuring a rotation of the magnetic field generated by the magnetic target based on measurements from magnetic sensors of the group of magnetic sensors; and Determining a fine position of the magnetic target based on the magnetic field rotation measured from the measurements of magnetic sensors of the group of magnetic sensors, and wherein the magnetic sensors of the array each comprise two magnetic sensing elements in a first substrate plane and a third magnetic sensing element in a second substrate plane approximately orthogonal to the first substrate plane. [11] The method of claim 10, wherein the fine position is a three-dimensional position, and wherein measuring the rotation comprises measuring the rotation of the magnetic target in three dimensions. [12] A magnetic sensor for detecting a position of a magnetic target, the magnetic sensor comprising: a first magnetic sensing element and a second magnetic sensing element positioned in a first substrate plane; a third magnetic sensing element and a fourth magnetic sensing element positioned in a second substrate plane oriented at a non-zero angle with respect to the first substrate plane, wherein a single integrated circuit includes the first, second, third, and fourth magnetic sensing elements; and one or more output contacts of the single integrated circuit configured to provide information from the first, second, third and fourth magnetic sensing elements indicative of a three-dimensional (3D) position of the magnetic target. [13] The magnetic sensor of claim 12, further comprising a processing circuit configured to receive data from the first, second, third and fourth magnetic sensing elements and calculate an angle of a magnetic field based on the received data. [14] A magnetic sensor according to claim 12 or claim 13, wherein the first magnetic sensing element comprises an anisotropic magnetoresistive (AMR) sensing element. [15] A magnetic sensor according to any one of claims 12 to 14, wherein the first magnetic sensing element comprises magnetoresistive elements arranged in a full-bridge configuration. [16] Magnetic sensor according to one of claims 12 to 15, wherein the first substrate plane is substantially orthogonal to the second substrate plane.

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