Magnetic sensor device, system and method, and force sensor

Abstract

A magnetic sensor system, comprising: an integrated circuit comprising a semiconductor substrate comprising a plurality of magnetic sensors configured to measure at least two first magnetic field components (Bx1, Bx2) oriented in a first direction (X) and to measure at least two second magnetic field components (Bz1, Bz2) oriented in a second direction (Y; Z); a permanent magnet movable relative to the integrated circuit and configured to generate a magnetic field; a processing circuit configured to determine at least two physical quantities (Fx, Fy, Fz) related to the position of the magnet using a predefined algorithm based on the measured first and second magnetic field components (Bx1, Bx2; Bz1, Bz2) or values ​​derived therefrom as inputs and using a plurality of at least eight constants determined using machine learning. A force sensor system. A joystick or thumb joystick system. A method.

Description

Technical Field

[0001] The present invention relates generally to the field of magnetic sensor devices, systems and methods, and more particularly to magnetic sensor devices, systems and methods in which the position of a magnet relative to a semiconductor substrate is indicative of at least two physical quantities, such as, for example, force components, or tilt angles of a joystick, or lateral positions of a thumb stick, etc. Background Art

[0002] Magnetic sensors (e.g., current sensors, proximity sensors, position sensors, etc.) are known in the art. They are based on measuring magnetic field characteristics at one or more sensor locations. Depending on the application, the measured magnetic field characteristic(s) can be used to infer another quantity (such as, for example, current intensity, proximity of a so-called target, relative position of the sensor device to a magnet, etc.).

[0003] There are many variations of magnetic sensor devices, systems, and methods that address one or more of the following requirements: use simple or inexpensive magnetic structures, use simple or inexpensive sensor devices, be able to measure over a relatively large range, be able to measure with high accuracy, require only simple arithmetic, be able to measure at high speed, be highly robust to positioning errors, be highly robust to external interference fields, provide redundancy, be able to detect errors, be able to detect and correct errors, have a good signal-to-noise ratio (SNR), etc. Two or more of these requirements often conflict with each other, so trade-offs need to be made.

[0004] The present invention relates to a class of magnetic sensor systems comprising a permanent magnet flexibly or elastically mounted relative to a semiconductor substrate and wherein the position of the magnet is indicative of a 2D or 3D physical quantity such as a force vector or a displacement vector caused by a force applied to a surface or caused by movement of a joystick or thumb joystick or the like.

[0005] There is always room for improvement or substitution. Summary of the invention

[0006] It is an object of embodiments of the present invention to provide a magnetic sensor system and method for determining at least two physical quantities related to the position of a permanent magnet that is movable relative to a semiconductor circuit.

[0007] It is an object of embodiments of the present invention to provide a system and method which is insensitive to external disturbing fields, and / or to temperature variations, and / or to demagnetization of the magnet, and preferably two or all of these.

[0008] It is an object of embodiments of the present invention to provide systems and methods that use algorithms that do not require explicit analytical or mathematical formulas or expressions.

[0009] Embodiments of the present invention are directed to wherein the magnets are embedded in an elastomer above or on top of the semiconductor circuit.

[0010] An object of an embodiment of the present invention is to provide a magnetic sensor system that uses only 2D magnetic sensors, or only 3D magnetic sensors, or a combination of 2D magnetic sensors and 3D magnetic sensors.

[0011] It is an object of embodiments of the present invention to provide a magnetic sensor system and method in which the magnetic field is measured in at least four sensor positions or at least five sensor positions.

[0012] It is an object of embodiments of the present invention to provide a magnetic sensor system and method wherein the magnet is an axially magnetized two-pole magnet.

[0013] It is an object of embodiments of the present invention to provide a magnetic sensor system and method in which the physical quantity is calculated by an integrated circuit.

[0014] It is an object of embodiments of the present invention to provide a magnetic sensor system and method wherein the time required to determine the at least two physical quantities is at most 50 ms, or at most 40 ms, or at most 30 ms, or at most 20 ms, or at most 10 ms.

[0015] An object of an embodiment of the present invention is also to provide a semiconductor device (ie a single chip) comprising at least a plurality of sensors for measuring a magnetic field and optionally also a processing circuit system for determining the at least two physical quantities.

[0016] An object of an embodiment of the present invention is also to provide a force sensor system.

[0017] It is an object of certain embodiments of the invention to provide a force sensor system capable of measuring two or three force components (ie 2D or 3D force vectors) using such a magnetic sensor system.

[0018] Embodiments of the present invention also aim to provide a robot finger comprising at least one force sensor system, and a robot arm comprising at least one robot finger.

[0019] Embodiments of the present invention also aim to provide a joystick system with two degrees of freedom (eg, two tilting movements), or with three degrees of freedom (two tilting movements, and downward movement).

[0020] Embodiments of the present invention also aim to provide a thumbstick system with two degrees of freedom (eg, two lateral movements), or with three degrees of freedom (two lateral movements, and downward movement).

[0021] These and other objectives are achieved by embodiments of the present invention.

[0022] According to a first aspect, the present invention provides a magnetic sensor system, the magnetic sensor system comprising: an integrated circuit, the integrated circuit comprising a semiconductor substrate, the semiconductor substrate comprising a plurality of magnetic sensors, the plurality of magnetic sensors being configured to measure at least two (or at least three, or at least four) first magnetic field components (Bx1, Bx2) oriented in a first direction (X), and to measure at least two (or at least three, or at least four) second magnetic field components (Bz1, Bz2) oriented in a second direction (Y; Z) (for example, perpendicular to the first direction (X)); a permanent magnet, the permanent magnet being movable relative to the integrated circuit and being configured to For generating a magnetic field; a processing circuit (inside the integrated circuit or outside the integrated circuit), the processing circuit being configured to determine at least two physical quantities related to the position of the magnet (for example, a 2D or 3D force vector, a 2D or 3D displacement vector, a 2D or 3D position of a joystick, a 2D or 3D position of a thumb joystick) using a predefined algorithm, the predefined algorithm being based on the measured first and second magnetic field components (Bx1, Bx2; Bz1, Bz2) or values ​​derived therefrom as input, and using a plurality of at least eight (or at least twelve, or at least eighteen) constants (or coefficients or parameters) determined using machine learning.

[0023] A “magnetic sensor system” may for example be a force sensor system, or a joystick, or a thumbstick.

[0024] The inventors have found that even if the magnet moves in a highly nonlinear manner, for example due to a specific mechanical mounting arrangement (e.g., using an elastomer with a nonlinear stress-strain curve), it is not required to find an explicit analytical expression or mathematical model that expresses the relationship between the physical quantity and the movement of the magnet with the minimum number of variables.

[0025] It was found that it is possible to determine very accurately a physical quantity by executing a predetermined algorithm using a number of constants (or parameters) determined by machine learning (ML). It was found that this approach allows determining or approximating the desired physical quantity in a manageable manner.

[0026] Those skilled in the art who have the benefit of this disclosure can readily find suitable algorithms to meet their needs simply by applying the teachings of the present invention.

[0027] Such a magnetic sensor system may be particularly suitable for applications where small errors in absolute accuracy do not adversely affect the application in which the magnetic sensor system is used.

[0028] In an embodiment, the processing circuit is configured to determine the at least two physical quantities using a predefined algorithm, which uses at least three or at least four magnetic field differences derived from the at least two first magnetic field components and the at least two second magnetic field components as input, and uses the plurality of at least eight (or at least twelve, or at least eighteen) constants.

[0029] As will be explained further, the magnetic field difference may be calculated as a magnetic field gradient, or may be calculated by subtracting a mean or average magnetic field component oriented in the same direction as the original magnetic field component.

[0030] In an embodiment, an integrated circuit comprises a first programmable processor, as part of said processing circuitry, configured to execute at least a part of said algorithm.

[0031] The processing circuit may be implemented on the same semiconductor die as the semiconductor die including the magnetic sensor, or may be implemented on a second semiconductor die that is connected to the first semiconductor die and also embedded in the same package as the first semiconductor die.

[0032] The integrated circuit may include analog processing circuitry, or may include digital processing circuitry using a programmable DSP (digital signal processor) core with MAC (multiply accumulate) instructions.

[0033] In this embodiment, the integrated circuit preferably includes outputs configured to provide at least two or three physical values ​​(eg, force value, angle value, etc.).

[0034] In an embodiment, the magnetic sensor system further includes a second programmable processor, which is part of the processing circuit, communicatively connected to the integrated circuit but located outside it; and the integrated circuit is configured to provide the at least three first and second magnetic field components (e.g., Bx1, Bx2, Bx3; Bz1, Bz2, Bz3) or values ​​derived therefrom to the second programmable processor.

[0035] In an embodiment, the integrated circuit includes a plastic molded package, and the elastomer is arranged on top of the molded package and in direct contact with the molded package. In some embodiments, the elastomer does not extend laterally beyond the package (i.e., is supported only by the package). In other embodiments, the elastomer may extend laterally beyond the package and may, for example, make contact with a printed circuit board on which the packaged device is mounted and / or soldered.

[0036] In an embodiment, the number of constants (also referred to as “coefficients”) is a value in the range from 12 to 100, or in the range from 12 to 80, or in the range from 18 to 64, or in the range from 25 to 45.

[0037] As a rule of thumb, the greater the number of coefficients, the higher the accuracy for a given measurement range, but the larger the circuitry (if implemented in hardware) or the greater the number of calculations (if implemented in software). However, the inventors have found that not only the number of constants has an impact on the computational effort and accuracy, but also the type of function used in the algorithm has an impact on the computational effort and accuracy.

[0038] In an embodiment, the semiconductor substrate further comprises a temperature sensor for measuring a temperature of the semiconductor substrate, and the semiconductor substrate is configured for correcting the measured first and second magnetic field components based on the measured temperature.

[0039] In an embodiment, the semiconductor substrate further comprises a temperature sensor for measuring the temperature of the semiconductor substrate, and the predefined algorithm takes the measured temperature into account as an additional input.

[0040] In an embodiment, the semiconductor substrate further comprises a temperature sensor for measuring the temperature of the semiconductor substrate, and the measured temperature is used in a post-processing step.

[0041] For example, in some embodiments, the measured temperature is used to correct the sensitivity of the sensor element. In some embodiments, the temperature is considered as an additional input (e.g., of a neural network). In some embodiments, for example in the case of using elastomers, the measured temperature can be used in a post-processing step, for example to compensate for temperature-dependent material properties (e.g., lower or higher stiffness).

[0042] In an embodiment, the plurality of sensors are configured to measure magnetic field components (eg, the first magnetic field component and the second magnetic field component described above) in only two orthogonal directions (eg, the first direction and the second direction).

[0043] In an embodiment, each of the first direction (eg, X) and the second direction (eg, Y) is parallel to the semiconductor substrate.

[0044] In this embodiment, the sensor is configured to measure (or only measure) the so-called "in-plane" magnetic field components (e.g., Bx and By). This can be achieved using vertical Hall elements, MR elements, horizontal Hall elements + IMC, or a combination thereof.

[0045] In an embodiment, the first direction (eg, X) is parallel to the semiconductor substrate, and the second direction (eg, Z) is perpendicular to the semiconductor substrate.

[0046] In this embodiment, the sensor is configured to measure (or only measure) a so-called "in-plane" magnetic field component (e.g., Bx or By) and a so-called "out-of-plane" magnetic field component (e.g., Bz). This can be achieved using a combination of horizontal Hall elements and vertical Hall elements, or a combination of MR elements and horizontal Hall elements, or a horizontal Hall element and an integrated magnetic flux concentrator (IMC).

[0047] In an embodiment, the plurality of magnetic sensors are further configured to measure at least three third magnetic field components oriented in a third direction perpendicular to the first direction and perpendicular to the second direction.

[0048] In this embodiment, the sensor is configured to measure two "in-plane" magnetic field components (e.g., Bx and By) and one "out-of-plane" magnetic field component (e.g., Bz). This can be achieved using a combination of horizontal Hall elements and vertical Hall elements, or a combination of MR elements and horizontal Hall elements, or a horizontal Hall element and IMC.

[0049] In an embodiment, the plurality of sensors includes at least one sensor (preferably at least two, or at least three, or at least four sensors), the at least one sensor comprising an integrated magnetic concentrator disk, and three pairs of horizontal Hall elements arranged near the periphery of the disk, the Hall elements being angularly spaced at multiples of 120°.

[0050] In an embodiment, the plurality of sensors includes at least one sensor (preferably at least two, or at least three, or at least four sensors), the at least one sensor comprising an integrated magnetic concentrator disk, and four pairs of horizontal Hall elements arranged near the periphery of the disk, the Hall elements being angularly spaced at multiples of 45°. Fig. 20 and Fig.21 An example of such a sensor is shown in the figure.

[0051] In an embodiment, the semiconductor substrate comprises a plurality of magnetic sensors located at intersections of a 2x2 grid (ie at the corners of an imaginary square), or at intersections of a 3x3 grid, or at intersections of a 4x4 grid. Preferably, the columns and rows of the grid are equally spaced.

[0052] In an embodiment, a semiconductor substrate includes a plurality of magnetic sensors arranged in an irregular pattern (eg, at pseudo-random locations).

[0053] In an embodiment, at least three of the magnetic sensors are located on a virtual circle.

[0054] The virtual circle may have a diameter in the range from 1.0 mm to 3.0 mm, or in the range from 1.5 mm to 2.5 mm, or in the range from 1.7 mm to 2.3 mm, for example a diameter equal to about 1.8 mm, or equal to about 2.0 mm, or equal to about 2.2 mm.

[0055] In an embodiment, the semiconductor substrate comprises three magnetic sensors located on the imaginary circle and angularly spaced apart by a multiple of 120°.

[0056] In an embodiment, the semiconductor substrate comprises four magnetic sensors located on the imaginary circle and angularly spaced apart by a multiple of 90°.

[0057] In an embodiment, the semiconductor substrate comprises five magnetic sensors located on the imaginary circle and angularly spaced apart by multiples of 72°.

[0058] In an embodiment, the semiconductor substrate comprises six magnetic sensors located on the imaginary circle and angularly spaced apart by multiples of 60°.

[0059] In an embodiment, the semiconductor substrate further comprises a magnetic sensor located at the center of the virtual circle.

[0060] In an embodiment, the magnet is a two-pole magnet (eg, a two-pole bar magnet, or a diametrically magnetized ring or disk magnet). The magnetization direction of the magnet may be oriented substantially perpendicular to the semiconductor substrate, or substantially parallel to the semiconductor substrate.

[0061] In an embodiment, the magnet is an axially magnetized magnet (eg, an axially magnetized ring or disk magnet).The magnetization direction of the magnet may be oriented substantially perpendicular to the semiconductor substrate, or substantially parallel to the semiconductor substrate.

[0062] In an embodiment, the sensor system comprises only one magnet.

[0063] In an embodiment, the sensor system comprises three magnets arranged on a virtual circle above the semiconductor substrate and angularly spaced 120° apart.

[0064] In an embodiment, the sensor system comprises four magnets arranged on a virtual circle above the semiconductor substrate and angularly spaced 90° apart.

[0065] In an embodiment, the sensor system comprises six magnets arranged on a virtual circle above the semiconductor substrate and angularly spaced 60° apart.

[0066] In an embodiment, the magnet(s) are two-pole disk magnet(s), each having an outer diameter or a maximum diagonal smaller than the diameter of the virtual circle on which at least three of the magnetic sensors are located.

[0067] In an embodiment, the magnet(s) are two-pole disk magnet(s) such that the outer diameter or maximum diagonal of each magnet is substantially equal to the diameter of the virtual circle on which at least three of the magnetic sensors are located (within ±20% of the diameter of the virtual circle).

[0068] In an embodiment, the magnet(s) are two-pole disk magnet(s) each having an outer diameter or a maximum diagonal greater than the diameter of the virtual circle on which at least three of the magnetic sensors are located.

[0069] In an embodiment, the magnet has a central axis that intersects the semiconductor substrate at a central location of the magnetic sensor ("on-axis arrangement").

[0070] In an embodiment, the magnet has a central axis that intersects the semiconductor substrate at a position offset from the central position of the magnetic sensor ("off-axis arrangement"). In case the sensors are arranged on an NxN grid, the offset may be half the distance between two adjacent grid lines.

[0071] In an embodiment, the magnet is an axially magnetized two-pole ring or disk magnet.

[0072] An advantage of using such magnets is that the magnetic field generated by such magnets is rotationally invariant, meaning that the magnetic field is independent of the rotation of the magnet about its axis. Thus, the magnetic sensor system is insensitive to torques about an axis perpendicular to the semiconductor substrate.

[0073] In an embodiment, the predefined algorithm is configured to derive at least two (or at least three, or at least four) first differences from the at least two (or at least three, or at least four) first magnetic field components, and to derive at least two (or at least three, or at least four) second differences from the at least two (or at least three, or at least four) second magnetic field components; and to calculate the at least two (or three, or four) physical values ​​(for example, force components, angles, or displacements) based on the at least two (or at least three, or four) first differences and the at least two (or at least three, or four) second differences.

[0074] It is explicitly pointed out that this part of the algorithm can be implemented within an integrated circuit containing the magnetic sensor, or outside the integrated circuit containing the magnetic sensor (for example, in an electronic control unit connected to the sensor device), or partly within the sensor device (for example, for some of the difference values) and partly outside the sensor device (for example, for some other difference values).

[0075] The main advantage of using the difference is that the result is highly insensitive to external interfering fields. To the best of the inventors' knowledge, there are no prior art force sensors that are immune to stray fields.

[0076] In an embodiment, the predefined algorithm further considers at least one first magnetic field component, or at least one second magnetic field component.Although this embodiment is not theoretically 100% stray field immune, it may still have relatively large stray field suppression.

[0077] In an embodiment, each of the at least three first difference values ​​is determined as a pairwise difference between two first magnetic field components, and wherein each of the at least three second difference values ​​is determined as a pairwise difference between two second magnetic field components; or

[0078] This may be referred to as a "magnetic field gradient" and may be written in mathematical terms, for example, as: dx1 = Bx1 - Bx2; dx2 = Bx1 - Bx3, dx3 = Bx2 - Bx3, and dz1 = Bz1 - Bz2; dz2 = Bz1 - Bz3, dz3 = Bz2 - Bz3.

[0079] In an embodiment, each of the at least three first difference values ​​is determined as a difference between a first magnetic field component and a first common value, and wherein each of the at least three second difference values ​​is determined as a difference between a second magnetic field component and a second common value.

[0080] The first common value may be the first magnetic field component measured at the fourth sensor position (preferably the central sensor position), or may be the average of at least three first magnetic field components. This may be referred to as "mean removal" and may be written in mathematical terms, for example, as follows (assuming that the semiconductor substrate has only three 2D sensors, each measuring Bx and Bz): Bx_avg = (Bx1 + Bx2 + Bx3), Bz_avg = (Bz1 + Bz2 + Bz3); dx1 = Bx1-Bx_avg, dx2 = Bx2-Bx_avg, dx3 = Bx3-Bx_avg, dz1 = Bz1-Bz_avg, dz2 = Bz2-Bz_avg, dz3 = Bz3-Bz_avg.

[0081] In an embodiment, the predefined algorithm is configured for calculating each of the physical values ​​as a sum of at least twelve terms, wherein each of the at least twelve terms is a function of one or more of the differences.

[0082] In an embodiment, each of these sums includes a constant value determined by machine learning.

[0083] Machine learning is typically applied on a batch basis rather than on an individual product basis.

[0084] In an embodiment, the predefined algorithm is configured to calculate each of the physical values ​​as a sum of at least twelve terms; at least two terms contain linear expressions of only one of the differences; and at least two terms contain non-linear expressions of one or more of the differences.

[0085] Thus, at least two of these terms are scaled versions of only one of the differences, for example: (K1*dx1) or (K2*dx1+K3), where the constants K1, K2, K3 are determined by machine learning.

[0086] In an embodiment, each of these terms is a constant or an algebraic function of one or more of the differences.

[0087] "Algebraic functions" are a class of functions that include: "polynomial functions" (e.g., constants, linear functions, quadratic functions, cubic power functions) and "rational functions" (i.e., the ratio of two polynomial functions). Algebraic functions also include "piecewise functions" such as absolute value functions, floor functions, ceiling functions, sign functions. Algebraic functions do not include so-called "transcendental functions," which are the set of functions in which the independent variable appears as an exponential, root exponential, logarithm, or trigonometric ratio.

[0088] In other words, in this embodiment, none of the terms is or includes an exponential function, or a logarithmic function, or a trigonometric function (e.g., sine, cosine, tangent, cosecant, secant, cotangent), or an inverse trigonometric function (e.g., arctangent).

[0089] Using "only" algebraic functions and excluding transcendental functions is an advantage because algebraic functions are cheaper in terms of processing power or processing time and can be implemented in embedded processors.

[0090] In an embodiment, at least two terms or each sum is or contains a quadratic expression or a second order polynomial of only one of said differences.

[0091] For example: K1*sqr(dx1), or K2*sqr(dx1-K3), or K4+(K5*dx1)+K6*(dx1)2, where K1 to K6 are constants.

[0092] In an embodiment, some of the terms are third-order or fourth-order polynomial expressions.

[0093] In a preferred embodiment, no term is a polynomial expression greater than four. Using polynomial orders of at most four, or at most three, or at most two is advantageous because it requires less processing time and less processing power.

[0094] In an embodiment, each sum contains at least one term that is the product of two differences (eg, K7*dx1*dz1).

[0095] It was found that using products of the difference signals does help improve the accuracy of the results. Although the inventors do not wish to be bound by any theory, it appears that certain products of the differences correlate well with the physical movement of the magnets, although this correlation is not immediately obvious to a human observer.

[0096] In an embodiment, each sum contains at least one term that is a division of two differences (eg, K8*dx1 / dz1).

[0097] Using a ratio of two magnetic field values ​​(eg, a difference) is advantageous because such a ratio is highly robust with respect to temperature variations and demagnetization effects.

[0098] In an embodiment, the predefined algorithm is executed by a trained neural network using at least three first magnetic field components (e.g., Bx1, Bx2, Bx3) and at least three second magnetic field components (e.g., Bz1, Bz2, Bz3) as input signals and providing at least two (or at least three) physical values ​​as output values.

[0099] The predefined algorithm may include a neural network having a plurality of layers, wherein each layer includes a plurality of nodes.

[0100] In an embodiment, the neural network comprises only one layer, the layer having between 12 and 100 nodes.

[0101] In an embodiment, the neural network comprises only two layers, each layer having 10 to 100 nodes, or having 20 to 60 nodes.

[0102] In an embodiment, the neural network comprises only three layers, each layer having 10 to 100 nodes, or each layer having 5 to 50 nodes.

[0103] In an embodiment, the neural network is a recurrent neural network (RNN).

[0104] In an embodiment, the neural network is an artificial neural network (ANN).

[0105] In an embodiment, the neural network is a convolutional neural network (CNN).

[0106] In an embodiment, the predefined algorithm further includes a post-processing step; and the post-processing step is configured to adjust the determined physical quantity (e.g., determined using the above-mentioned proprietary algorithm, or determined using a neural network) by adding or subtracting an offset value determined by a separate calibration test.

[0107] “Individual calibration testing” means that the test is performed individually for each magnetic sensor system, in contrast to machine learning, which is not performed on an individual basis but rather is typically performed on a batch-by-batch basis.

[0108] This "individual calibration test" is preferably performed as an EOL test (End of Line Test), or it can be performed by the OEM customer.

[0109] In the case of a force sensor system or force sensor device or joystick, etc., the calibration test may include: (i) performing force measurements while applying zero force using a predefined algorithm by using multiple constants or parameters determined by machine learning (which are typically determined on a batch basis) to produce two or three force values ​​or position values ​​that are typically slightly deviated from zero; and (ii) storing these values ​​in a non-volatile memory of the system (e.g., a non-volatile memory of an integrated circuit).

[0110] During normal use of the sensor device, first a predefined algorithm is used to provide two or more measurement values ​​based on parameters determined by machine learning, and then a correction is applied by subtracting the values ​​measured during the calibration step explained above.

[0111] The main advantage of this embodiment is that it combines the best of two worlds, namely: a very good approximation to a physical value that is measured but then corrected using a predefined algorithm using multiple constants determined on a batch basis by machine learning, so that the "zero force" or "neutral position" of a joystick, etc. is offset corrected for each individual product.

[0112] In an embodiment, the magnet is flexibly mounted relative to the integrated circuit by means of a flexible material.

[0113] The flexible material can be a single layer of isotropic material without any voids or hollow areas. The material and the shape and size of the magnet can be designed so that the magnet can move in three directions X, Y, Z, but will not rotate significantly about its center (e.g., will rotate less than ±10°, or less than ±5° within the measurement range of the force sensor system).

[0114] In an embodiment, the flexible material is a polymer.

[0115] In an embodiment, the flexible material is an elastomer.

[0116] The elastomer may be arranged above or on top of the integrated circuit. In a preferred embodiment, the elastomer may directly contact the package of the integrated circuit.

[0117] In an embodiment, the elastomer is or includes silicone (eg, silicone rubber (eg, natural rubber)).

[0118] In an embodiment, the flexible material has a nonlinear stress-strain characteristic; and a linear regression coefficient of a portion of the nonlinear stress-strain characteristic corresponding to a measurement range of the magnetic sensor system is less than 0.90, or less than 0.85, or less than 0.80, or less than 0.75, or less than 0.70.

[0119] In other words, in these embodiments, the curve showing strain as a function of stress for the material is a highly non-linear function.

[0120] In an embodiment, the predefined algorithm further comprises a post-processing step, in which the temperature of the flexible material is measured or estimated and wherein the determined physical quantity is corrected to reduce temperature-dependent material properties.

[0121] The correction can be carried out individually using a predefined correction function for each determined physical quantity.

[0122] The compensation function may be, for example, a temperature-dependent scaling.The function f(.) may be stored in the form of a lookup table, or as a piecewise linear approximation, or as an analytical function (eg, as a polynomial expression).

[0123] A temperature sensor may be integrated inside the integrated circuit and the temperature of the temperature sensor may be used as an estimate of the elastic body.

[0124] In an embodiment, the predefined algorithm further comprises a post-processing step, or if already present, the post-processing step further comprises: performing an offset correction for each output value by subtracting a predefined value stored in the non-volatile memory during the calibration process.

[0125] The present invention also provides a force sensor system comprising the magnetic sensor system according to the first aspect, wherein at least two or three physical quantities to be determined are two or three force components (Fx, Fy, Fz) of the mechanical force applied on the contact surface of the flexible material.

[0126] The magnetic sensor system may be referred to as a “force sensor system” and the integrated circuit may be referred to as a “force sensor device”.

[0127] The force components Fx and Fy are often referred to as shear forces or lateral forces. The force component Fz is often referred to as downward pressure.

[0128] In an embodiment, a flexible material is located above or on top of the integrated circuit (eg, as a layer deposited on a package), and the magnets are at least partially or fully embedded within the flexible material.

[0129] A plurality of constants (or parameters or coefficients) can be determined by applying a series of tests in which a plurality of known forces having only the Fx component are applied, followed by another series of tests in which a plurality of known forces having only the Fy component are applied, followed by another series of tests in which a plurality of known forces having only the Fz component are applied. In each series of tests, the respective component values ​​are assumed to be values ​​within the respective predefined measurement ranges.

[0130] Alternatively, a plurality of constants (or parameters or coefficients) may be determined by applying a series of tests in which three-dimensional forces are applied, the three-dimensional forces having Fx, Fy, Fz components in their respective measurement ranges.

[0131] In an embodiment, multiple constants are determined by applying a series of known forces, where each of the Fx, Fy and Fz values ​​"swept" their respective measurement ranges, for example each in 5 steps, i.e. 5*5*5=125 different combinations; or each in 6 steps, i.e. 6*6*6=216 different combinations; or each in 7 steps, i.e. 343 combinations; or each in 8 steps, i.e. 512 combinations; or each in 9 steps, i.e. 729 combinations; or each in 10 steps, i.e. 1000 different combinations.

[0132] In an embodiment, no external disturbance field is applied during these steps. Needless to say, this is a huge advantage, as the influence of external disturbance fields is substantially eliminated by design (by taking into account gradient or mean correction values).

[0133] In another embodiment, an external disturbance field is applied during the steps.The external disturbance field may assume a pseudo-random value for each step.

[0134] The invention also provides a robotic finger comprising at least one force sensor system.

[0135] The present invention also provides a robotic hand comprising at least two robotic fingers.

[0136] The present invention also provides a joystick system or a joystick assembly for determining the 2D or 3D position of a joystick, the joystick system or the joystick assembly comprising: a magnetic sensor system according to the first aspect; and a joystick movable with at least two degrees of freedom relative to an integrated circuit; wherein a magnet is fixedly connected to the joystick.

[0137] The joystick system may determine, for example, two angle values ​​indicating the position of the joystick, for example, Fig.31 As shown in FIG. . The joystick may be rotatable about a pivot point. The pivot point may be located above the magnet. In other words, the magnet may be located between the pivot point and the semiconductor substrate.

[0138] Joysticks may be used in consumer electronics applications (eg, for gaming) or in agricultural vehicles.

[0139] An exemplary embodiment of a joystick includes a bearing by means of which the joystick is mounted to move with at least two degrees of freedom relative to a housing. The joystick has a portion movable by a user and an inner portion, which are opposite to each other on different sides of the bearing in a longitudinal direction. A magnet is arranged on the joystick. A semiconductor substrate having a plurality of magnetic sensors is arranged at a fixed position relative to the housing.

[0140] The present invention also provides a thumb joystick system or a thumb joystick assembly for determining the 2D or 3D position of a thumb joystick, the thumb joystick system or the thumb joystick assembly comprising: a magnetic sensor system according to the first aspect; and a thumb joystick movable with at least two or three degrees of freedom relative to an integrated circuit; wherein the magnet is fixedly connected to the thumb joystick.

[0141] The thumbstick system may determine, for example, two lateral displacement values ​​indicating the position of the stick, and optionally also give an indication of whether a drumstick is pressed (or pushed down).

[0142] According to another aspect, the present invention also provides a method for measuring at least two physical quantities related to the position of a permanent magnet (e.g., a 2D or 3D force vector, a 2D or 3D displacement vector, a 2D or 3D position of a joystick, a 2D or 3D position of a thumb joystick), wherein the permanent magnet can move relative to an integrated circuit and is configured to generate a magnetic field, the method comprising the following steps: a) measuring at least two (or at least three) first magnetic field components (e.g., Bx1, Bx2; Bx1, Bx2, Bx3) oriented in a first direction (e.g., X); b ... direction perpendicular to the first direction (e.g., X); at least two (or at least three) second magnetic field components (e.g., Bz1, Bz2; Bz1, Bz2, Bz3) oriented in a second direction (e.g., Y or Z) in one direction (e.g., X); c) determining the at least two physical quantities using a predefined algorithm, the predefined algorithm using the measured first magnetic field component and the second magnetic field component (e.g., Bx1, Bx2, Bx3; Bz1, Bz2, Bz3) as input, and using a plurality of at least eight (or at least twelve, or at least sixteen) constants (or coefficients or parameters) determined using machine learning.

[0143] In an embodiment, the method has one or more of the above features.

[0144] According to another aspect, the present invention also provides an integrated semiconductor device, comprising: a plurality of sensors, the plurality of sensors having Figure 3(a) to Figure 21 22( a) and 22( b) and one or both of the boxes 2224 (mean removal) and 2232 (gradient calculation), and is configured to output the value provided by the boxes 2223 or 2232 via an output interface (e.g., a serial bus using, for example, I2C or SPI or SENT protocol).

[0145] According to another aspect, the present invention also provides a force sensor device or system, comprising: an integrated circuit, the integrated circuit comprising a semiconductor substrate, the semiconductor substrate comprising a plurality of magnetic sensors, the plurality of magnetic sensors being configured to measure at least two (or at least three, or at least four) first magnetic field components (e.g., Bx1, Bx2) oriented in a first direction (e.g., X), and to measure at least two (or at least three, or at least four) second magnetic field components (e.g., Bz1, Bz2) oriented in a second direction (e.g., Y or Z), for example, perpendicular to the first direction (e.g., X); a permanent magnet, which is movable relative to the integrated circuit and is configured to generate a magnetic field; a processing circuit (inside the integrated circuit or outside the integrated circuit), the processing circuit being configured to determine at least two magnetic field gradients (e.g., dBx / dx, dBz / dx) derived from the magnetic field components, and to determine one or two or three force components (e.g., Fx, Fy, Fz) based on the at least two magnetic field gradients.

[0146] According to another aspect, the present invention also provides a force sensor device, comprising: an integrated circuit, the integrated circuit comprising a semiconductor substrate, the semiconductor substrate comprising a plurality of magnetic sensors, the plurality of magnetic sensors being configured to measure at least three or at least four magnetic field components oriented in a first direction, or being configured to measure at least a first and a second magnetic field components oriented in the first direction and to measure at least a third and a fourth magnetic field components oriented in a second direction; a permanent magnet, the permanent magnet being flexibly mounted to the integrated circuit by means of a flexible material, the permanent magnet generating a magnetic field; a processing circuit, the processing circuit being configured to determine at least one physical quantity or at least two physical quantities related to the position of the magnet relative to the sensor device, or to the force or pressure applied to the flexible material, based on at least two or at least three pairwise differences of the magnetic field components.

[0147] In an embodiment, the processing circuit is implemented on the same semiconductor substrate as the magnetic sensor. In another embodiment, the processing circuit is implemented on a first semiconductor substrate (e.g., a CMOS substrate) and the magnetic sensor is implemented on one or more sensor substrates (e.g., CMOS, Ga-As, Ga-In, or In-Sb) mounted next to, on top of, or below the first semiconductor substrate.

[0148] In an embodiment, the second direction is the same as the first direction. In another embodiment, the second direction is different from the first direction (eg, the second direction is orthogonal to the first direction).

[0149] The force sensor device can be configured to determine the physical quantity using one or more predefined functions. The function or functions can be stored in the non-volatile memory of the processing circuit, for example, in the form of a mathematical formula (e.g., as a polynomial expression with multiple coefficients (e.g., with 3 to 30 coefficients (e.g., with at least 3 or at least 4 or at least 6 or at least 8 or at least 12 coefficients)); or in the form of a sum with 3 to 15 terms (e.g., with at least 3 terms, or at least 4 terms, or at least 6 terms, or at least 8 terms, or at least 10 terms, or at least 12 terms); or in the form of a lookup table. Some terms may be the square of the magnetic field difference, or may be the cross product of two magnetic field differences obtained from a pair of sensors spaced apart in the same direction, or may be the cross product of two magnetic field differences obtained from a pair of sensors spaced apart in different directions.

[0150] The coefficients or parameters may be determined using machine learning. Alternatively, the coefficients or parameters may be determined using classical techniques such as, for example, using curve fitting techniques, linear or nonlinear regression techniques, or linear or nonlinear models.

[0151] The force sensor device may have three 1D pixels, or four 1D pixels, or three 2D pixels, or four 2D pixels, or five 2D pixels, or six 2D pixels, or seven 2D pixels, or eight 2D pixels, or nine 2D pixels, or four 2D pixels and one 3D pixel, or four 3D pixels, or five 3D pixels, or nine 3D pixels.

[0152] In an embodiment, at least two pairwise differences are determined, or at least three pairwise differences are determined, or at least four pairwise differences are determined, or at least six pairwise differences are determined, or at least eight pairwise differences are determined, and (one or more) output values ​​are determined based on these pairwise differences.

[0153] Particular and preferred aspects of the invention are set out in the accompanying independent and dependent claims. Features from the dependent claims may be combined with features of the independent claims and with features of other dependent claims as appropriate and not just as explicitly set out in the claims.

[0154] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0155] FIG. 1 is a schematic block diagram of a sensor circuit known in the art.

[0156] FIG. 2 is a schematic block diagram of a sensor circuit known in the art.

[0157] 3( a ) is a schematic representation of an illustrative example of a magnetic sensor system including a permanent magnet movable relative to a semiconductor substrate.

[0158] FIG. 3( b ) is a schematic representation of another illustrative example of a magnetic sensor system including a permanent magnet movable relative to two semiconductor substrates arranged side by side.

[0159] Figures 4 to 21 is a schematic block diagram of a sensor circuit that may be used in embodiments of the present invention.

[0160] FIG. 22( a ) shows a schematic block diagram of a magnetic sensor system proposed by the present invention.

[0161] FIG. 22( b ) shows a schematic block diagram of another magnetic sensor system proposed by the present invention.

[0162] Figure 23(a) to Figure 23(e) Examples of mechanical arrangements or sensor assemblies that may be used in embodiments of the present invention are shown.

[0163] Figures 24(a) and 24(b) show pictures of the force sensor system prototype.

[0164] Figure 24(c) shows a picture of the mechanical setup used to apply a known force.

[0165] 25( a ) and 25 ( b ) show the results of measurement values ​​of Bx and Bz when a force Fz oriented in a direction perpendicular to the semiconductor substrate is applied.

[0166] Fig.26 A computer model that can be used to simulate the mechanical arrangement of an embodiment of the present invention including an elastomer is shown.

[0167] Figures 27(a) and 27(b) show how well the forces measured by the calibration setup correspond to the forces predicted by the force sensor algorithm.

[0168] Figure 27(c) and Figure 27(d) show the "force error histogram".

[0169] Fig.28 is a graph illustrating the error of the measured shear force Fx as a function of an external disturbance field applied in the X direction with and without the mean removal block.

[0170] Fig.29 A graph illustrating the magnitude of a force Fz directed in a direction towards the semiconductor substrate versus the displacement of a magnet is shown.

[0171] Fig.30 is a schematic block diagram of a sensor device 3010 that may be used in embodiments of the present invention.

[0172] Fig.31 The principles used to illustrate the present invention can also be used to determine the tilt angles φ and ψ of the joystick assembly.

[0173] Fig.32 A flow chart of a method 3200 for measuring at least two physical quantities related to the position of a permanent magnet proposed by the present invention is shown.

[0174] These drawings are only schematic and non-limiting. In the drawings, for illustrative purposes, the size of some of the elements may be exaggerated and not drawn to scale. Any reference numerals in the claims should not be construed as limiting the scope. In different drawings, the same reference numerals refer to the same or similar elements. DETAILED DESCRIPTION

[0175] The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims.

[0176] The terms first, second, etc. in the specification and in the claims are used to distinguish between similar elements and not necessarily to describe a sequence in time, space, level, or in any other manner. It should be understood that the terms so used are interchangeable under appropriate circumstances, and that the embodiments of the invention described herein are capable of operating in a sequence different from that described or illustrated herein.

[0177] The terms top, bottom, etc. in the specification and claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in orientations other than those described or illustrated herein.

[0178] It should be noted that the term "comprising" used in the claims should not be interpreted as being limited to the means listed thereafter; it does not exclude other elements or steps. Thus, the term should be interpreted as specifying the presence of the stated features, integers, steps or components as mentioned, but does not exclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression "a device comprising means A and B" should not be limited to devices consisting only of component A and component B. It means that for the present invention, the only relevant components of the device are A and B.

[0179] References throughout this specification to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification do not necessarily all refer to the same embodiment, but may. Furthermore, in one or more embodiments, as would be apparent to one of ordinary skill in the art from this disclosure, the particular features, structures, or characteristics may be combined in any suitable manner.

[0180] Similarly, it should be appreciated that in the description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. However, this method of disclosure should not be interpreted as reflecting an intention that the claimed invention requires more features than those expressly recited in each claim. On the contrary, as reflected in the appended claims, the inventive aspects lie in fewer features than all of the features of a single preceding disclosed embodiment. Thus, the claims appended to the Detailed Description are hereby expressly incorporated into the Detailed Description, with each claim itself representing a separate embodiment of the invention.

[0181] In addition, although some embodiments described herein include some features included in other embodiments but do not include other features included in these other embodiments, as will be understood by those skilled in the art, the combination of features of different embodiments is intended to fall within the scope of the present invention and form different embodiments. For example, in the appended claims, any of the embodiments claimed for protection may be used in any combination.

[0182] In the description provided herein, numerous specific details are set forth. However, it should be understood that embodiments of the present invention may be implemented without these specific details. In other examples, well-known methods, structures, and techniques are not shown in detail to avoid confusion in understanding this description.

[0183] In this document, unless explicitly mentioned otherwise, the term "magnetic sensor device" or "sensor device" refers to a device comprising at least two magnetic sensor elements, which device is preferably integrated in a semiconductor substrate. The sensor device may be included in a package (also referred to as a "chip"), but that is not absolutely necessary.

[0184] In this document, the term “sensor element” or “magnetic sensor element” refers to a single vertical Hall element or a single horizontal Hall element or a single magnetoresistive element (eg a GMR element or an XMR element).

[0185] In this document, the term "magnetic sensor" or "magnetic sensor structure" may refer to a set of components or subcircuits or structures capable of measuring magnetic quantities, such as, for example, a set of at least two magnetic sensor elements, or a Wheatstone bridge containing four MR elements.

[0186] In certain embodiments of the present invention, the term "magnetic sensor" or "magnetic sensor structure" may refer to an arrangement including one or more integrated magnetic concentrators (IMCs) (also referred to as integrated flux concentrators) and two or four or eight horizontal Hall elements arranged near the periphery of the IMCs.

[0187] In this document, the expressions "in-plane component of the magnetic field vector" and "orthogonal projection of the magnetic field vector in the sensor plane" mean the same thing. If the sensor device is or comprises a semiconductor substrate, this also means "the magnetic field component parallel to the semiconductor substrate".

[0188] In this document, the expressions “out-of-plane component of a vector” and “Z-component of a vector” and “orthogonal projection of the vector onto an axis perpendicular to the sensor plane” mean the same thing.

[0189] Embodiments of the present invention are typically described using an orthogonal coordinate system fixed to the sensor device and having three axes X, Y, Z, wherein the X-axis and the Y-axis are parallel to the substrate and the Z-axis is perpendicular to the substrate.

[0190] In this document, the expressions "spatial derivative" or "derivative" or "spatial gradient" or "gradient" are used as synonyms. In the context of the present invention, the gradient is usually determined as the difference between two values ​​measured at two different positions that may be spaced apart by a distance in the range from 1.0 mm to 3.0 mm. In theory, the gradient is calculated as the difference between the two values ​​divided by the distance "dx" between the sensor positions, but in practice the division by "dx" is often omitted, since the measured signal needs to be scaled anyway.

[0191] In this document, horizontal Hall plates are typically referred to as H1, H2, etc., and signals from these horizontal Hall plates are typically referred to as h1, h2, etc.; vertical Hall plates are typically referred to as V1, V2, etc.; and signals from these vertical Hall plates are typically referred to as v1, v2, etc.

[0192] In this document, the terms "multiple coefficients", or "multiple parameters" or "multiple constants" mean the same thing when referring to machine learning or deep learning, regardless of whether the values ​​are used as coefficients in a matrix, or as offset values, or as scaling factors.

[0193] The present invention relates generally to the field of magnetic sensor devices, systems and methods, and more particularly to magnetic sensor devices, systems and methods in which the position of a magnet relative to a semiconductor substrate is indicative of at least two physical quantities, such as, for example, force components, or tilt angles of a joystick, or lateral positions of a thumb stick, etc.

[0194] Refer to the attached drawings.

[0195] FIG1 is a schematic block diagram of a sensor circuit known in the art. The sensor circuit includes a first sensor (or sensor structure) at a first sensor position X1 along the X-axis and a second sensor (or sensor structure) at a second sensor position X2; each sensor structure includes an integrated magnetic concentrator (IMC) and two horizontal Hall elements arranged on opposite sides of the IMC, and these sensor structures are also referred to as "2D magnetic pixels" in this article. Each of these 2D magnetic pixels is capable of measuring the Bx and Bz magnetic field components at the center of the IMC disk. The sensor circuit with two 2D pixels in FIG1 can be used to determine two magnetic field gradients dBx / dx and dBz / dx along the X-axis.

[0196] FIG2 is a schematic block diagram of a sensor circuit known in the art, which is a variation of FIG1 . The sensor circuit includes a first sensor structure at a first sensor position X1 along the X-axis and a second sensor structure at a second sensor position X2; each sensor structure includes an integrated magnetic concentrator (IMC) and four horizontal Hall elements arranged at the periphery of the IMC, and these sensor structures are also referred to herein as "3D magnetic pixels". Two of the four horizontal Hall elements are located on the X-axis, and the other two of the four horizontal elements are located on the Y-axis perpendicular to the X-axis. The sensor circuit with two 3D pixels of FIG2 can be used to determine three magnetic field gradients dBx / dx, dBy / dx, and dBz / dx along the X-axis.

[0197] FIG3( a) is a schematic representation of an illustrative example of a magnetic sensor system including a permanent magnet that can move relative to a semiconductor substrate. The semiconductor substrate includes a plurality of magnetic sensors. Although not explicitly shown in FIG3( a), the semiconductor substrate can be embedded in a packaged device and the magnet can be embedded in an elastomer located above or on top of the packaged device. The magnet can be an axially magnetized two-pole disk magnet.

[0198] FIG3( b) is a schematic representation of another illustrative example of a magnetic sensor system including a permanent magnet that can move relative to two semiconductor substrates arranged side by side and each including a plurality of magnetic sensors. Although not explicitly shown in FIG3( b), the semiconductor substrate can be embedded in a single packaged device and the magnet can be embedded in an elastomer located above or on top of the packaged device. The magnet can be an axially magnetized two-pole disk magnet.

[0199] Figure 4 3( a) or 3( b) or a variant thereof. When the sensor circuit is used in the magnetic sensor system of FIG. 3( a) or FIG. 3( b) or a variant thereof, the magnet is preferably located substantially above the center of the virtual circle.

[0200] Figure 5 is a schematic block diagram of a sensor circuit that can be used in an embodiment of the present invention. The sensor circuit comprises four 2D magnetic pixels, three of which are located on a virtual circle, and one of which is located at the center of the virtual circle. Figure 5 The sensor circuit of can be viewed as a 2D magnetic pixel with an additional one located at the center. Figure 4 A variant of the sensor circuit of FIG. 3( a) or FIG. 3( b) or a variant thereof. The sensor circuit can measure eight magnetic field components of the magnetic field generated by the magnet, which eight magnetic field components may be referred to herein as (Bx1, Bz1) at the first sensor position, (Bx2, Bz2) at the second sensor position, (Bx3, Bz3) at the third sensor position, and (Bx4, Bz4) at the fourth sensor position. When the sensor circuit is used in the magnetic sensor system of FIG. 3( a) or FIG. 3( b) or a variant thereof, the magnet is preferably located substantially above the center of the virtual circle.

[0201] exist Figure 5 In a variant (not shown), the sensor located at the center is a 3D magnetic pixel instead of a 2D magnetic pixel (e.g., as Fig.13 and Figure 15(a)-Figure 15(b) ), and is configured to measure three orthogonal magnetic field components Bx4, By4, Bz4 at a fourth sensor position.

[0202] Figure 6 3( a) or 3( b) or a variant thereof, the magnet is preferably located substantially above the center of the virtual circle.

[0203] The inventors came to the surprising insight that, at least in theory, these four sensor signals should be sufficient to uniquely determine the 3D position of the magnet relative to the semiconductor substrate or a physical quantity related to said position even in the presence of magnetic interference fields, since only Bz_ext is unknown (in this case, Bx_ext and By_ext are unrelated).

[0204] exist Figure 6 In a variant (not shown), the sensor circuit includes five horizontal Hall elements, four of which are located on a virtual circle, angularly spaced at multiples of 90°, and one of which is located at the center of the virtual circle. The sensor circuit is capable of measuring Bz1 to Bz5.

[0205] exist Figure 6 In a variant (not shown), the sensor circuit includes four vertical Hall elements, each element having a maximum sensitivity axis oriented in a single direction (e.g., X direction) parallel to the semiconductor substrate. The sensor circuit is capable of measuring Bx1 to Bx4. In another variant, the sensor circuit includes a fifth vertical Hall element located at the center of the virtual circle.

[0206] exist Figure 6In a variant (not shown), the sensor circuit includes four magnetoresistive (MR) elements, each element having a maximum sensitivity axis oriented in a single direction (e.g., X direction) parallel to the semiconductor substrate. The sensor circuit is capable of measuring Bx1 to Bx4. In another variant, the sensor circuit includes a fifth MR element located at the center of the virtual circle.

[0207] exist Figure 6 In a variant (not shown), the sensor circuit comprises an array of horizontal Hall elements (without IMC), each element being configured to measure Bz in a direction perpendicular to the semiconductor substrate, the elements being, for example, located on an N×M grid, where N and M are integer values ​​in the range from 2 to 5, for example, on a 2×4 grid, a 3×3 grid, a 3×4 grid, a 3×5 grid, a 4×4 grid, etc. The grid lines may be vertical, but this is not absolutely necessary. The distance between parallel grid lines may be constant, but this is also not absolutely necessary. Not all positions of the array need to be occupied by Hall elements.

[0208] exist Figure 6 In another variant (not shown), the sensor circuit includes a plurality of at least four magnetic sensors that are only horizontal Hall elements (without IMC), located at random or pseudo-random positions (e.g., not located on a circle or square or grid, and / or not equidistantly spaced from each other), each configured to measure Bz in a direction perpendicular to the semiconductor substrate.

[0209] FIG7( a) is a schematic block diagram of a sensor circuit that can be used in an embodiment of the present invention. The sensor circuit includes four 2D magnetic pixels located on a virtual circle and spaced apart by multiples of 90° in angle. The sensor circuit can measure eight magnetic field components of the magnetic field generated by the magnet, which may be referred to herein as (Bx1, Bz1) at the first sensor position, (Bx2, Bz2) at the second sensor position, (Bx3, Bz3) at the third sensor position, and (Bx4, Bz4) at the fourth sensor position. When the sensor circuit is used in the magnetic sensor system of FIG3( a) or FIG3( b) or a variant thereof, the magnet is preferably located substantially above the center of the virtual circle.

[0210] FIG. 7( b ) shows a variation of FIG. 7( a ) in which all 2D pixels are rotated by 45°.

[0211] Figure 8 is a schematic block diagram of a sensor circuit that can be used in an embodiment of the present invention. The sensor circuit includes five 2D magnetic pixels, four of which are located on a virtual circle and are angularly spaced at multiples of 90°, and one of which is located at the center of the virtual circle. Figure 8 The sensor circuit of can be regarded as a variant of the sensor circuit of FIG. 7( a) with an additional 2D magnetic pixel located at the center. The sensor circuit can measure ten magnetic field components of the magnetic field generated by the magnet, which can be referred to herein as (Bx1, Bz1) at the first sensor position, (Bx2, Bz2) at the second sensor position, (Bx3, Bz3) at the third sensor position, (Bx4, Bz4) at the fourth sensor position, and (Bx5, Bz5) at the fifth sensor position. When the sensor circuit is used in the magnetic sensor system of FIG. 3( a) or FIG. 3( b) or a variant thereof, the magnet is preferably located substantially above the center of the virtual circle.

[0212] exist Figure 8 In a variant (not shown), the sensor S5 located at the center is a 3D magnetic pixel instead of a 2D magnetic pixel (e.g., Fig.13 and shown in FIG. 15 ), and is configured to measure three orthogonal magnetic field components Bx5, By5, Bz5 at a fifth sensor position.

[0213] Fig. 9 3(a) or 3(b) or variants thereof, the magnet is preferably located substantially above the center sensor position (in its default position).

[0214] Fig.10 is a schematic block diagram of a sensor circuit that can be used in an embodiment of the present invention. The sensor circuit includes an array of 3×3=9 (nine) 2D magnetic pixels located on a grid having three rows and three columns. The sensor circuit can measure nine sets of two magnetic field components (Bu, Bz), each of which measures 2×9=18 (eighteen) magnetic field components in total. If the X direction is selected to be parallel to the row direction and the Y direction is selected to be parallel to the column direction, the U direction forms a 45° angle with the X direction. Fig.10 The sensor circuit can be viewed as a circuit in which each of the sensors is rotated 45° around the Z axis. Fig. 9 When the sensor circuit is used in the magnetic sensor system of FIG. 3( a ) or FIG. 3( b ) or a variant thereof, the magnet (when in its default position) is preferably located substantially above the central sensor position.

[0215] FIG11( a) is a schematic block diagram of a sensor circuit that can be used in an embodiment of the present invention. The sensor circuit includes an array of eight 2D magnetic pixels located on a grid having three rows and three columns. The sensor circuit can be considered as a circuit in which the center sensor is omitted and in which the two Hall elements of each sensor are located on a virtual line passing through the center position. Fig. 9 Variants of sensor circuits.

[0216] In a variation (not shown) of FIG. 11( a ), the sensor circuit further includes a 3D magnetic pixel having only four horizontal Hall elements located on an imaginary line parallel to the row and column directions, as depicted in FIG. 11( b ).

[0217] In a variation (not shown) of FIG. 11( a ), the sensor circuit further includes a 3D magnetic pixel having only four horizontal Hall elements located on an imaginary line forming an angle of 45° with respect to the row and column directions, as depicted in FIG. 11( c ).

[0218] In a variation of FIG. 11( a ) (not shown), the sensor circuit further includes a 3D magnetic pixel having eight horizontal Hall elements spaced at multiples of 45° (two of the eight horizontal Hall elements are located in rows and two of the eight horizontal Hall elements are located in columns), as depicted in FIG. 11( d ).

[0219] Fig.12 is a schematic block diagram of a sensor circuit that can be used in an embodiment of the present invention. The sensor circuit includes four 2D magnetic pixels located on a virtual circle. The two Hall elements of each sensor are located on radially oriented segments. The sensor structure is capable of measuring (Bx1, Bz1) at a first sensor position, (Bx2, Bz2) at a second sensor position, (By3, Bz3) at a third sensor position, and (By4, Bz4) at a fourth sensor position, thereby measuring a total of eight magnetic field components.

[0220] Fig.13 is a schematic block diagram of a sensor circuit that can be used in an embodiment of the present invention. The sensor circuit can be considered to further include a 3D magnetic pixel located at the center of a virtual circle, Fig.12 A variant of the sensor circuit of . The sensor circuit is capable of measuring (4x2)+(1x3)=8+3=11 magnetic field components.

[0221] FIG14( a) is a schematic block diagram of a sensor circuit that can be used in an embodiment of the present invention. The sensor circuit includes four 3D magnetic pixels located on a virtual circle and spaced at multiples of 90°. In this example, each sensor includes an IMC disk having four horizontal Hall elements, two of which are located on a virtual line parallel to the X direction, and two of which are located on a virtual line parallel to the Y direction. The sensor circuit is capable of measuring two in-plane field components (Bx, By) at four sensor positions, and is capable of measuring an out-of-plane field component Bz at four sensor positions, thereby being able to measure a total of sixteen magnetic field components. In other words, the sensor circuit is capable of measuring four magnetic field components tangent to the virtual circle, a magnetic field component radially oriented relative to the virtual circle, and four axially oriented magnetic field components.

[0222] Figure 14(b) is a schematic block diagram of a sensor circuit that may be used in embodiments of the present invention. The sensor circuit may be viewed as a variation of the sensor circuit of Figure 14(a) in which each sensor is rotated 45° relative to the Z axis perpendicular to the semiconductor substrate.

[0223] FIG15( a) is a schematic block diagram of a sensor circuit that can be used in an embodiment of the present invention. The sensor circuit can be viewed as a variant of the sensor circuit of FIG14( a) that further includes a 3D magnetic pixel located at the center of a virtual circle. The sensor circuit is capable of measuring (5x3)=15 magnetic field components.

[0224] Figure 15(b) is a schematic block diagram of a sensor circuit that may be used in embodiments of the present invention. The sensor circuit may be viewed as a variation of the sensor circuit of Figure 15(a) in which each sensor is rotated 45° relative to the Z axis perpendicular to the semiconductor substrate.

[0225] Fig.16 is a schematic block diagram of a sensor circuit that can be used in an embodiment of the present invention. The sensor circuit includes an array of 3×3=9 (nine) 3D magnetic pixels located on a grid having three rows and three columns. The sensor circuit can measure nine sets of three magnetic field components (Bx, By, Bz), each of which measures 3×9=27 magnetic field components in total. The sensor circuit can be viewed as a 3D magnetic pixel in which each 2D magnetic pixel is replaced by a 3D magnetic pixel. Fig. 9 Variants of sensor circuits.

[0226] exist Fig.16 In a variant (not shown), each sensor is rotated 45° around the Z axis perpendicular to the semiconductor substrate. The sensor is capable of measuring nine sets of three orthogonal magnetic field components (Bu, Bv, Bz), nine components oriented in the U direction, nine components oriented in the V direction, and nine components oriented in the Z direction.

[0227] FIG. 17( a) is a schematic block diagram of a sensor circuit that can be used in an embodiment of the present invention. The sensor circuit can be viewed as Fig.12 A variant of a sensor circuit in which each sensor comprises a horizontal Hall element (without IMC) configured to measure an out-of-plane magnetic field component Bz and comprises one (or at least one) vertical Hall element having an axis of maximum sensitivity oriented in a radial direction.

[0228] In a variation of FIG. 17( a) (not shown), each sensor has two vertical Hall elements oriented in the same direction but radially spaced apart, such as one vertical Hall element on either side of a horizontal Hall element, one at a larger imaginary circle and one at a smaller imaginary circle. The signals from the two corresponding vertical Hall elements can be added or averaged.

[0229] FIG. 17( b ) shows a variation of FIG. 17( a ) in which all 2D pixels are rotated by 45°.

[0230] Fig.18 is a schematic block diagram of a sensor circuit that can be used in an embodiment of the present invention. The sensor circuit can be viewed as a variation of the sensor circuit of FIG. 7( a) : wherein each sensor comprises a horizontal Hall element (without IMC) configured to measure an out-of-plane magnetic field component Bz, and comprises one (or at least one) vertical Hall element having a maximum sensitivity axis oriented in the X direction.

[0231] exist Fig.18 In a variant (not shown), the sensor circuit further includes a fifth sensor located at the center of the virtual circle, which fifth sensor also has a horizontal Hall element (without IMC) for measuring the Bz component and at least one vertical Hall element for measuring the Bx component at the center of the virtual circle.

[0232] FIG19( a) is a schematic block diagram of a sensor circuit that can be used in an embodiment of the present invention. The sensor circuit can be viewed as a variant of the sensor circuit of FIG14( a) where each sensor includes a horizontal Hall element (without IMC) configured to measure an out-of-plane magnetic field component Bz, and includes two vertical Hall elements having a maximum sensitivity axis oriented in the X direction and located on opposite sides of the horizontal Hall element, and includes two vertical Hall elements having a maximum sensitivity axis oriented in the Y direction and located on opposite sides of the horizontal Hall element. In other words, the horizontal Hall element is surrounded by four vertical Hall elements located on each side of the square. Each of these sensors is capable of measuring three orthogonal magnetic field components (Bx, By, Bz) to form a 3D magnetic pixel.

[0233] In a variant (not shown) of Figure 19(a), the sensor circuit further includes a fifth 3D magnetic pixel located at the center of the virtual circle. The sensor circuit can measure five sets of three magnetic field components (Bx, By, Bz), thereby measuring a total of 5×3=15 magnetic field components.

[0234] FIG19( b) is a schematic block diagram of a sensor circuit that can be used in an embodiment of the present invention. The sensor circuit can be viewed as a variant of the sensor circuit of FIG19( a) in which each sensor is rotated 45° around the Z axis perpendicular to the semiconductor substrate. The sensor circuit includes four 3D magnetic pixels, each of which is capable of measuring an out-of-plane magnetic field component Bz oriented in the Z direction perpendicular to the semiconductor substrate, and in addition, each 3D magnetic pixel is capable of measuring two in-plane magnetic field components (Bu, Bv) oriented in the U direction and the V direction.

[0235] In a variant (not shown) of Figure 19(b), the sensor circuit further comprises a fifth 3D magnetic pixel located at the center of the virtual circle. The sensor circuit is capable of measuring five sets of three orthogonal magnetic field components (Bx, By, Bz), thereby measuring a total of 5×3=15 magnetic field components.

[0236] Fig. 20 14(a) or 14(b) : The sensor circuit includes four sensors, each sensor including an integrated magnetic concentrator disk IMC, and eight horizontal Hall elements located near the periphery of the IMC disk and spaced at multiples of 45° in angle. Each of these sensors is capable of measuring four in-plane magnetic field components Bx, By, Bu, Bv and one out-of-plane magnetic field component Bz. The sensor circuit is capable of measuring 4×5=20 magnetic field components.

[0237] Fig.21 is a schematic block diagram of a sensor circuit that can be used in an embodiment of the present invention. The sensor circuit can be viewed as further comprising a fifth 3D magnetic pixel located at the center of the virtual circle. Fig. 20 A variant of the sensor circuit of . The sensor circuit is capable of measuring five sets of five orthogonal magnetic field components (Bx, By, Bu, Bv, Bz), thereby measuring a total of 5×5=25 magnetic field components.

[0238] In all the above embodiments (FIGS. 1 to 2) in which one or more integrated magnetic concentrators IMC are used Fig.21 ), the IMC preferably has a disk shape with a height of about 17 to 23 μm and a diameter of about 170 to 230 μm.

[0239] In all of the above embodiments in which the magnetic sensors (also referred to herein as 2D magnetic pixels or 3D magnetic pixels) are located on a virtual circle, the diameter of the virtual circle is preferably 1.7 to 2.3 mm, for example, equal to about 1.9 mm, or equal to about 2.0 mm, or equal to about 2.1 mm. In embodiments in which the sensors are located on a 3×3 grid, the distance between the grid lines is preferably about 0.7 mm to about 1.5 mm, or from about 0.9 mm to about 1.3 mm.

[0240] The horizontal Hall plate generally has a square shape with an area ranging from 15 μm×15 μm to 25 μm×25 μm, for example equal to about 20 μm×20 μm.

[0241] Figure 22 (a) shows a schematic block diagram of a magnetic sensor system 2200 proposed by the present invention, which can be used to measure one or two or three physical quantities related to the position of a permanent magnet, such as, for example, three orthogonal components of a force vector applied to the sensor system. The system may further be affected by external interference fields (also called stray fields) and by varying temperatures.

[0242] The sensor system 2200 includes one or more semiconductor substrates including a plurality of magnetic sensors 2210. The one or more semiconductor substrates are preferably incorporated into a semiconductor package (also referred to as a sensor chip), see, for example, FIG. 23( d ). In a preferred embodiment, the plurality of magnetic sensors are incorporated into a single semiconductor substrate that is less than 3.0 cm×3.0 cm (preferably, less than 2.5 mm×2.5 mm).

[0243] The sensor system further comprises a permanent magnet which is flexibly or elastically mounted relative to the semiconductor substrate(s), for example by means of an elastic material.

[0244] The permanent magnet 390, 2390 is preferably a single axially magnetized annular or disk-shaped magnet having an outer diameter of about 1.2 mm to about 1.8 mm (e.g., equal to about 1.5 mm); and having a height (in the axial direction) of about 0.3 mm to about 0.7 mm, or from 0.4 mm to 0.6 mm (e.g., equal to about 0.5 mm). In a preferred embodiment, the outer diameter of the permanent magnet is smaller than the diameter of the virtual circle on which the sensor element is located.

[0245] The permanent magnet may be mounted with the aid of a rod and bearings etc. (as is often the case in a joystick), or may be mounted with the aid of one or more springs, or may be embedded in a flexible material (e.g. in an elastomer), such as shown in FIGS. 3(a) and 3(b), or as shown in Figure 23(a) to Figure 23(e) , or as shown in the prototypes of FIG. 24( a) and FIG. 24( b), or as shown in Fig.26or as described in co-pending EP application number EP21182116.0, filed on June 28, 2021 by the same applicant and entitled “Force sensor with target on semiconductor package”, which document is incorporated by reference in its entirety (especially FIGS. 1 to 21). Figure 5 and corresponding description, which illustrates and describes the assembly of the force sensor with the elastomer), or included herein in any other suitable manner. The elastomer may have highly nonlinear stress-to-strain characteristics, making it extremely difficult or almost impossible to find a clear analytical formula for determining the component of the mechanical force applied to the magnet based on the signal obtained from the magnetic sensor. An additional problem encountered by the inventors is that the mechanical properties of the elastic material may also be temperature dependent. For example, over the envisioned temperature range, the elastic material may become harder as the temperature decreases. The permanent magnet and the mechanical mounting of the magnet are schematically represented by box 2204, which generates a magnetic field that depends on the applied mechanical force, but it can also be said that the magnetic field generated by the permanent magnet is "modulated" by the mechanical force.

[0246] Influences from (unknown) external interfering fields are usually added to the magnetic field generated by the magnet.

[0247] In the example of Figure 22(a), a mechanical force 2202 is applied to a magnet, and the physical quantity to be measured is the force components in the X, Y, and Z directions, and the present invention will be explained primarily with respect to a force sensor, keeping the description relatively simple, but the present invention is not limited thereto, and is also applicable to determining other physical quantities, such as, for example, determining the position of a joystick (e.g., two tilt angles), or determining the position of a thumb joystick (e.g., two lateral displacements, and / or downward displacements), and the like.

[0248] The mechanical force to be measured can be applied directly or indirectly to the magnet, for example, directly or indirectly to the contact surface of an elastic body enclosing the permanent magnet. The latter may be preferred, for example, to avoid slipping. The magnetic field generated by the permanent magnet can be detected by a sensor circuit including a plurality of magnetic sensors 2210 (for example, using Figure 3(a) to Figure 21 22(a) ) to measure, the invention is not limited thereto, since, for example, sensor circuits having a plurality of sensor elements located on a 4×4 grid or at pseudo-random positions will also work. In practice, magnetic sensors are typically biased with a current or voltage source, and the signal provided by the sensor element is typically amplified and digitized, etc., in a so-called "bias and readout circuit", which is not explicitly shown in FIG. 22(a) , since such circuits are well known in the art and are not the focus of the present invention, and therefore do not need to be explained in more detail here. It can be said that techniques such as "spin current", chopping, etc. may also be used.

[0249] The processing of the signals will be explained mainly with reference to the prototypes illustrated in Figures 3(b) and 7(b), which have been built, evaluated and simulated. But of course the invention is not limited to this example but also applies to other systems using the same principle.

[0250] The sensor circuit of FIG. 7( b ) provides eight magnetic field component signals: Bx1 , Bz1 , Bx2 , Bz2 , Bx3 , Bz3 , Bx4 , Bz4 , whereby in the example of the prototype, block 2210 provides these eight signals.

[0251] In block 2222, the eight magnetic field component signals are preferably amplified and offset corrected and sensitivity corrected in a known manner, for example, according to temperature. To this end, the sensor circuit preferably further includes a temperature sensor 2208. For completeness, it should be noted that this block can not only correct for temperature changes, but also correct for mechanical stresses applied to the silicon substrate in a known manner, for example, as described in co-pending patent application EP21161150.4 (publication number: EP3885779), and / or as described in co-pending patent application EP21161151.2 (publication number: EP3885778), both of which are incorporated herein by reference in their entirety, or in any other suitable manner. Block 2222 can also digitize the signal using one or more analog-to-digital converters ADC (not explicitly shown).

[0252] In the example of FIG. 22( a), four sensitivity-corrected Bx signals are input to block 2224, where the mean or average of the four sensitivity-corrected Bx signals is calculated and then subtracted from each of the sensitivity-corrected Bx signals. Similarly, four sensitivity-corrected Bz signals are input to block 2224, where the mean or average of the four sensitivity-corrected Bz signals is calculated and then subtracted from each of the sensitivity-corrected Bz signals. If implemented in this manner, block 2224 outputs four "mean-corrected" Bx-related signals and four "mean-corrected" Bz-related signals, for a total of eight signals. It is also possible to perform "mean removal" in the analog domain and digitize the mean-corrected Bx values ​​and mean-corrected Bz values.

[0253] In the example of FIG. 22( a), the processing circuit further includes a "feature expansion and polynomial expansion" block 2226 configured to receive four mean-corrected Bx values ​​and four mean-corrected Bz values, and to calculate one or more of the following: the sum of two values, the difference of two values, the product of two values, the ratio of two values, the square of a value, the sign of a value multiplied by the square of a value, the cube of a value, the absolute value of a value, the sum of the squares of two (e.g., orthogonal) values ​​(related to the "norm"), the sum of the squares of three (e.g., orthogonal) values ​​(related to the "norm"); and to output the (original) mean-corrected Bx and Bz values ​​and the additionally generated values ​​as output signals. In a preferred embodiment, the total number of values ​​"Ntot" provided by block 2226 is a value in the range from 12 to 100, or in the range from 12 to 80, or in the range from 16 to 64.

[0254] It should be noted that the difference between "feature expansion" and "polynomial expansion" is somewhat arbitrary and not relevant to the present invention. What is important is that block 2226 takes a certain number of input values ​​and generates a plurality of output values ​​(e.g., the same number, or preferably a larger number) based on values ​​derived therefrom. It was surprisingly found that by expanding the number of values, the accuracy of the final output (e.g., force components) was greatly improved, which is counterintuitive because these values ​​do not add "new information". In particular, it was found to be very advantageous to add additional values ​​in the form of squares of input values, and / or in the form of products of similar input values ​​(e.g., Bx1*Bx2), and / or in the form of different input values ​​(e.g., Bx1*Bz1).

[0255] In block 2230 , the physical quantity to be determined is calculated from these values, more specifically as a weighted sum of these values, each biased by an offset.

[0256] For example, if block 2226 outputs values ​​v1, v2, ... v64, block 2230 may calculate one or more components of the force vector (Fx, Fy, Fz) according to the following formula:

[0257] Fx=A1*(v1-B1)+A2*(v2-B2)+...+A64*(v64-B64)[1]

[0258] Fy=C1*(v1-D1)+C2*(v2-D2)+...+C64*(v64-D64)[2]

[0259] Fz=E1*(v1-F1)+E2*(v2-F2)+...+E64*(v64-F64)[3]

[0260] Among them, the values ​​A1 to A64, B1 to B64, C1 to C64, D1 to D64, E1 to D64, and F1 to F64 are constants, which are determined by machine learning or by deep learning.

[0261] It should be noted that the "training" or "learning" is done over a relatively wide range of 3D force values, i.e., a sufficient number of various combinations of 3D force components are selected to represent the 3D space of possibilities. In other words, the coefficients are trained using many combinations of forces (Fx, Fy, Fz), e.g., the number of measurements is at least 2 times or at least 5 times (e.g., about 10 times) the number of parameters to be determined.

[0262] There is an optional "Temperature Correction Box" 2225, as discussed in Fig.29 In the case where temperature is used as an additional part of box 2226 (representing feature enhancement and / or polynomial enhancement box, or neural network), "training" or "learning" should be performed using various combinations of (T, Fx, Fy, Fz).

[0263] FIG22( b) shows a schematic block diagram of another magnetic sensor system 2250 proposed by the present invention, which can be used to measure one or two or three physical quantities related to the position of the permanent magnet, such as, for example, three orthogonal components of the force vector applied to the sensor system. The system can be regarded as a variant of the system of FIG22( a) in which the mean removal block 2224 is replaced by the gradient calculator block 2232.

[0264] If the sensor circuit 2210 includes multiple sensors as depicted in FIG. 7( b ), the gradient calculator block may calculate one or more of the following Bx-related gradient signals:

[0265] g1=(Bx1-Bx3), g2=(Bx1-Bx4), g3=(Bx1-Bx2),

[0266] g4=(Bx3-Bx4), g5=(Bx3-Bx2), g6=(Bx4-Bx2)

[0267] And one or more of the following Bz-related gradient signals can be calculated:

[0268] g7=(Bz1-Bz3), g8=(Bz1-Bz4), g9=(Bz1-Bz2)

[0269] g10=(Bz3-Bz4), g11=(Bz3-Bz2), g12=(Bz4-Bz2)

[0270] All other things mentioned above for the system of Figure 22(a) also apply here.

[0271] It should be noted that in contrast to many prior art magnetic sensor systems in which analytical formulas are used, in the present invention there is no requirement that the signals entering block 2226 behave like sine and cosine functions of the physical quantity to be determined.

[0272] In an embodiment (not shown), a predefined algorithm is executed by a trained neural network using at least three first magnetic field components (e.g., Bx1, Bx2, Bx3) and at least three second magnetic field components (e.g., Bz1, Bz2, Bz3) as input signals and providing at least two (or at least three) physical values ​​as output values.

[0273] The neural network may replace blocks 2226 and 2230 of Figures 22(a) and 22(b). Optionally, in this case, blocks 2224 (mean removal) and 2232 (gradient calculator) may be omitted.

[0274] The predefined algorithm may include a neural network having a plurality of layers, wherein each layer includes a plurality of nodes. In an embodiment, the neural network comprises only one layer, which has 12 to 100 nodes. In an embodiment, the neural network comprises only two layers, each layer having 10 to 100 nodes, or having 20 to 60 nodes. In an embodiment, the neural network comprises only three layers, each layer having 10 to 100 nodes, or each layer having 5 to 50 nodes. In an embodiment, the neural network is a recurrent neural network (RNN). In an embodiment, the neural network is an artificial neural network (ANN). In an embodiment, the neural network is a convolutional neural network (CNN).

[0275] Figure 23(a) to Figure 23(e) An example of a mechanical arrangement including a sensor device or including a sensor assembly 2300 is shown, including a sensor device 2392, such as a packaged chip, which includes a semiconductor substrate enclosed in a molding compound; and an elastomer 2391, which is above or on top of the sensor device 2392; and a magnet 2390, which is embedded in the elastomer and located at a distance "d" (commonly referred to as an "air gap") from the sensor device. The sensor device can be mounted on a printed circuit board (PCB) 2393. The elastomer 2391 can be supported only by the semiconductor device, for example, as shown in FIG. Figure 23(c) to Figure 23(e)Alternatively, part of the elastomer may be supported by a printed circuit board, for example, as shown in FIG. 23( a) and FIG. 23( b). Optionally, there may be an intermediate layer (e.g., a glue layer) between the sensor chip 2392 and the elastomer 2391, for example, as shown in FIG. 23( d).

[0276] The magnet 2390 is preferably an axially magnetized annular or disk-shaped magnet. The outer diameter of the magnet can have a size comparable to the size of the sensor device (e.g., equal to, greater than, or less than the diameter of the virtual circle on which the magnetic sensor is located). However, preferably, the outer diameter of the magnet 2390 is less than the maximum distance between the magnetic sensor elements.

[0277] In the example of FIG. 23( a ), the magnet may have a height of approximately 8 mm (in the vertical direction, perpendicular to the semiconductor substrate) and a diameter of approximately 12 mm (parallel to the semiconductor substrate).

[0278] In the sensor assemblies illustrated in Figures 23(b) and 23(c), the magnet may have a diameter in the range of 5mm to 10mm and a height of approximately 3.5mm.

[0279] In the sensor assembly illustrated in FIG23( d ), the magnet may have a diameter of less than 2.5 mm or less than 2.0 mm (e.g., equal to about 1.5 mm); and may have a height of about 0.5 mm to about 1.0 mm. The thickness of the elastomer 2391 may be in the range of from 2.0 mm to 5.0 mm, or in the range of from 2.5 mm to 4.0 mm (e.g., equal to about 3.0 mm).

[0280] A skilled artisan with the benefit of this disclosure can easily find the appropriate size by considering the following rule of thumb: the larger the magnet, and / or the closer the magnet is to the semiconductor substrate; and the softer the elastomeric material, the larger the signal obtained from the magnetic sensor element.

[0281] 24( a ) and 24 ( b ) show pictures of a prototype of a force sensor system as described herein and used to develop and evaluate the algorithm described in FIGS. 22( a ) and 22( b ).

[0282] Figure 24(c) shows a picture of a mechanical setup for applying known forces (Fx, Fy, Fz) to a force sensor assembly. By applying a series of tests at different force values, and by measuring the corresponding magnetic field components, the parameters (e.g., A1 to F64) are determined using machine learning (ML).

[0283] Fig. 25(a) shows the results of the measurement values ​​of Bx1 to Bx4 when a force Fz oriented in a direction perpendicular to the semiconductor substrate and having an amplitude in the range of 0.0 Newton to 12.5 Newton is applied, and Fig. 25(b) shows the results of the measurement values ​​of Bz1 to Bz4 when a force Fz oriented in a direction perpendicular to the semiconductor substrate and having an amplitude in the range of 0.0 Newton to 12.5 Newton is applied. It can be seen that there is a certain spread between the curves, and the curves are not perfectly linear.

[0284] Surprisingly, the inventors have found that the values ​​of Bx1 to Bx4 show a very good correlation with the applied force and are thus very good indicators of the force component Fz, despite their relatively small values ​​(approximately 5 to 15 mT). Surprisingly, the inventors have also found that, despite the fact that the signals of the values ​​Bz1 to Bz4 are generally approximately twice the signals of Bx1 to Bx4, the differences between the values ​​Bz1 to Bz4 are very large. This was not expected. It shows that applying the analytical formula to any of the individual signals Bx1 to Bx4 and Bz1 to Bz4 will probably not result in a reliable measurement of the applied force component Fz, but as will be further shown, a combination of these signals (more specifically, a polynomial combination of these signals (e.g., a second order polynomial) and an algebraic combination of these signals (e.g., a product or ratio)) with a sufficient number of parameters can produce good results.

[0285] Fig.26 A computer model of a mechanical arrangement is shown which can be used to simulate how an elastic body deforms and how a magnet moves when a force with a normal force component Fz and / or with a shear force component Fx, Fy is applied. The computer model can be simulated using, for example, a commercially available tool called "Comsol".

[0286] use Figure 14(a)-Figure 14(b) The mechanical setup shown, for a given set of parameters determined by machine learning (e.g., A1 to F64), Fig.26 The computer model can then be used to validate the algorithm of Figure 22(a) or Figure 22(b) using these parameters.

[0287] Figures 27(a) and 27(b) show how the forces measured by the calibration setup (see Figure 24(c)) and predicted by the force sensor algorithm of the prototype implementation (see Figure 22(a)) work. Figure 27(a) relates to the forces in the "downward" direction, which are oriented in the negative Z direction, perpendicular to the semiconductor substrate. Figure 27(b) relates to the shear forces. It can be seen that there is a very good linear fit between the values.

[0288] It should be surprising that although no By component is measured, it is indeed possible to measure the applied force in the Y direction.

[0289] It should be noted that these results were obtained using the sensor circuit of FIG. 7( b ), which has only four 2D magnetic pixels that may not be oriented in an optimal direction.

[0290] It is contemplated that sensor circuits in which 2D pixels are oriented in different directions, and / or have more than four magnetic pixels, and / or have 3D magnetic pixels, and / or use algorithms with more parameters may provide more accurate results. However, it is not easy to predict how many sensors and / or how many parameters are needed to achieve a certain accuracy, or to predict the most cost-effective solution to achieve a certain accuracy. Even so, the present invention discloses a large number of solutions that produce workable and even very good results, even if they are not perfect.

[0291] FIG27( c ) shows a “force error histogram” when measuring (or determining) a force directed in the negative Z direction (denoted as Fz) using the sensor system of FIG22( a ). It can be appreciated that the vast majority of measurements (>97%) are accurate, with a maximum error within ±0.25 N (corresponding to a weight error of approximately ±25 grams), which is good enough for many applications, including many robotic applications where a robotic arm with a robotic finger needs to gently grasp an object without damaging it.

[0292] Figure 27(d) shows a "force error histogram" when measuring shear forces (ie, oriented parallel to the semiconductor substrate). It can be appreciated that the vast majority of measurements (>97%) are accurate, with a maximum error within ±0.15 N (corresponding to a weight error of approximately ±15 grams).

[0293] Fig.28 22 (a) is a graph showing the error of Fx according to the external interference field applied in the X direction with and without the mean removal block 2224 of FIG. 22 (a). The graph clearly shows that "mean removal" is a very effective method for removing the influence of stray fields. Similar results are expected when the gradient calculation block 2232 of FIG. 22 (b) is used.

[0294] Fig.29 A graph illustrating the magnitude (in arbitrary units) of the "normal force" Fz directed in the direction toward the semiconductor substrate versus the displacement (in arbitrary units) of the magnet is shown. It can be seen that the behavior is not completely linear, which may be due to the fact that the stiffness of the elastomer generally increases with increasing pressure applied to the elastomer.

[0295] Although Fig.29It is not explicitly shown in the present invention, but the inventors have also found that the stiffness of the elastomer also depends on the temperature. Tests have shown that this effect can be taken into account by a post-processing step, in which the values ​​of Fx, Fy, Fz are corrected according to the temperature, for example according to the following formula:

[0296] Fx_corr = Fx (using equation [1]) * [1 + K (Tchip-35)] [4]

[0297] Fy_corr = Fy (using equation [2]) * [1 + K (Tchip-35)] [5]

[0298] Fz_corr = Fz (using equation [3]) * [1 + K (Tchip-35)] [6]

[0299] Where Tchip(T 芯片 ) is the temperature in degrees Celsius measured by the on-chip temperature sensor, and K is a constant that can be determined during a calibration step.

[0300] This effect can also be taken into account in the optional "Temperature Correction" block 2225, for example according to the following formula:

[0301] Scorr=Sraw.[1+α(Tchip-35)]+β(Tchip-35)[7]

[0302] Where Tchip is the temperature in degrees Celsius measured by the on-chip temperature sensor, Sraw(S 原始 ) is the original signal value (e.g., mean-corrected value or gradient value) obtained from the previous block 2226 or 2232, Scorr (S 校正 ) is the temperature corrected signal value, α and β are two constants that can be determined by simulation or in a calibration step.

[0303] Fig.30 is a schematic block diagram of a sensor device 3010 that may be used in embodiments of the present invention. This block diagram is provided for completeness only.

[0304] The sensor device 3010 includes a semiconductor substrate including a plurality of magnetic sensors, only five of which are shown as M1 to M5, for example, Figures 4 to 21 Any circuit shown in the circuit.

[0305] The sensor device further includes bias and readout circuitry (e.g., as part of the processing circuit 3030) configured to receive signals m1, m2, etc. from the magnetic sensor. The signals are typically amplified and offset corrected. Preferably, the sensor device further includes a temperature sensor, and the magnetic sensitivity of the sensor element is preferably corrected based on the temperature (in the analog or digital domain). The processing circuit may further include at least one analog to digital converter (ADC) for converting the analog signal into a digital signal.

[0306] Depending on the implementation, the processing circuit 3030 may be further configured to perform one or more of the functions of blocks 2224 (mean removal), 2232 (gradient calculation), 2226 (feature expansion and polynomial expansion), 2230 (weights and biases) as described above, see Figures 22 (a) and 22 (b). In this case, the sensor device 3010 may output force component values ​​Fx, Fy, Fz. In order to be able to measure the applied force at a relatively high rate (e.g., at a frequency of at least 20 Hz, or at a frequency of at least 25 Hz, or at a frequency of at least 30 Hz, or at a frequency of at least 40 Hz), the number of expanded values ​​may be limited, and the complexity of the function used in the (polynomial) expansion block 2226 may be limited to algebraic functions (e.g., including square functions and products, but excluding division), and the number of terms to be added in block 2230 may be limited to a maximum of 50 terms, or a maximum of 40 terms, or a maximum of 36 terms. Such algorithms may be executed by a programmable signal processor (DSP), and a number of constants may be stored in the non-volatile memory 3031. Although not explicitly shown, it is also possible to use analog processing circuitry (e.g., an analog or digital accelerator, or an analog or digital coprocessor).

[0307] However, in other embodiments, the processing circuit will measure the magnetic field value (box 2210), and will implement sensitivity correction (box 2222), and may also optionally implement mean removal (2224) or gradient calculation (2232), but will not implement feature expansion (box 2226), and will not calculate the weighted sum (box 2230). In this case, the sensor device 3010 can output the value of box 2222, or 2224 or 2232 (preferably, the output is a digital value), and provide these values ​​to the external processor. The external processor will then perform feature and / or polynomial expansion (box 2226) and calculate the weighted sum (box 2230). The advantage of this implementation is that the external processor 3040 can be much more powerful, for example, with a clock frequency higher than 1.0 GHz, and / or can have multiple processor cores, and / or can have much more random access memory (random access memory, RAM) (for example, at least 1 GB of RAM).

[0308] In order to allow an external processor to perform post-processing corrections to account for the temperature dependence of the stiffness of the elastomer, the sensor device 3010 may also output the measured temperature T to the external processor.

[0309] Fig.31 It is provided for completeness to illustrate that the principles of the present invention can also be used to determine the tilt angles φ and ψ of a joystick assembly, wherein the magnet can be rotated about the pivot point 3101 by means of a handle or rod 3102.

[0310] The main advantage of embodiments of the present invention is that no explicit formula is required to determine the tilt angle, and the solution is highly insensitive to external interfering fields. It should be noted that in this case, no elastomeric material is required, but rather mechanical components would conventionally be used to hold the magnet and allow the magnet to move. A person skilled in the art will understand that Figure 3(a) to Figure 21 The sensor circuit shown in and the algorithm described above in Figures 22(a) and 22(b) can also be used to determine the tilt angle of the handle of the joystick assembly (a physical quantity related to the position of the magnet).

[0311] Although not explicitly shown, the principles of the present invention can also be used to determine the position of a thumb stick. In this case, by moving the thumb stick in a plane parallel to the semiconductor substrate, the magnet will be movable in a plane parallel to the semiconductor substrate. Optionally, one or more springs may be involved. Those skilled in the art will appreciate that Figure 3(a) to Figure 21 The sensor circuit shown in and the algorithm described above in Figures 22(a) and 22(b) can also be used to determine at least the lateral displacement of the thumb stick of the thumb stick assembly, and optionally, also determine the downward squeeze displacement (i.e., a physical quantity related to the position of the magnet).

[0312] Needless to say, the accuracy and robustness requirements of a thumb joystick assembly (e.g., as part of a gaming console for consumer electronics applications) with respect to interfering signals are quite different from those for robotic applications. In other words, it is quite feasible to build an integrated sensor device that performs all of the signal processing steps shown in Figures 22(a) and 22(b), albeit with a limited number of terms and constants, and with limited accuracy.

[0313] Fig.32 A flow chart of a method 3200 for measuring at least two physical quantities (e.g., a 2D or 3D force vector, a 2D or 3D displacement vector, a 2D or 3D position of a joystick, a 2D or 3D position of a thumbstick) related to the position of a permanent magnet that is movable relative to an integrated circuit and configured to generate a magnetic field is shown. The method 3200 includes the following steps:

[0314] a) measuring (3201) at least two (or at least three, or at least four) first magnetic field components (Bx1, Bx2; Bx1, Bx2, Bx3; Bx1 to Bx4) oriented in a first direction (e.g., X); the first direction can be parallel to the semiconductor substrate ("in-plane").

[0315] b) optionally determining (3202) a first gradient (e.g., dBx / dx) or a first mean-corrected value of said first magnetic field component;

[0316] c) measuring (3203) at least two (or at least three, or at least four) second magnetic field components (e.g., Bz1, Bz2; Bz1, Bz2, Bz3; Bz1 to Bz4) oriented in a second direction (e.g., Y or Z) perpendicular to the first direction (X). The second direction may be parallel to the semiconductor substrate ("in-plane") or may be perpendicular to the semiconductor substrate ("out-of-plane").

[0317] d) optionally determining (3204) a second gradient (e.g., dBz / dx) or a second mean-corrected value of the second magnetic field component;

[0318] e) determining the at least two physical quantities (e.g., Fx, Fy, Fz) using a predefined algorithm that uses the measured magnetic field components and / or gradients and / or mean-corrected values ​​as input, and uses a plurality of at least eight (or at least twelve, or at least sixteen) constants (or coefficients or parameters) determined using machine learning (ML) or deep learning.

[0319] Of course, the method can be further refined in the same manner as described above.

[0320] For example, in an embodiment, the at least two physical quantities may be determined using a predefined algorithm that uses as input at least three or at least four magnetic field differences derived from the at least two first magnetic field components and the at least two second magnetic field components, and uses the plurality of at least eight constants.

[0321] In another embodiment or further embodiment, the method may further include measuring the temperature of the semiconductor substrate; and correcting the measured first magnetic field component and the second magnetic field component based on the measured temperature, or considering the measured temperature as an additional input to a predefined algorithm, or processing the temperature in a post-processing step.

[0322] etc.

[0323] For completeness, it should be noted that blocks 2226 (mean removal) and 2232 (calculating gradients) can be omitted and stray fields are still eliminated by blocks 2226 and 2230 (which can be neural networks).

[0324] According to another aspect, the present invention also provides a force sensor device, comprising: an integrated circuit including a plurality of magnetic sensors; and a permanent magnet flexibly mounted to the integrated circuit by means of a flexible material (e.g., an elastomer); and a processing circuit. The processing circuit can be implemented on the same semiconductor substrate as the magnetic sensors, but this is not absolutely necessary, and the processing circuit can be implemented on a first semiconductor substrate (e.g., a CMOS substrate), and the magnetic sensors can be implemented on one or more sensor substrates (e.g., CMOS, or Ga-As, Ga-In, or In-Sb) mounted next to, on top of, or below the first semiconductor substrate, the one or more sensor substrates being mounted next to, on top of, or below the first semiconductor substrate in a manner similar to that described in US2022099709(A1), which is incorporated herein by reference in its entirety.

[0325] The plurality of magnetic sensors may be configured to measure at least three or at least four magnetic field components oriented in a first direction, or may be configured to measure at least a first and a second magnetic field component oriented in a first direction and to measure at least a third and a fourth magnetic field component oriented in a second direction. The second direction may be the same as the first direction, or may be different from (e.g., orthogonal to) the first direction.

[0326] The permanent magnet is configured to generate a magnetic field.

[0327] The processing circuit is configured to determine at least one pairwise difference, or at least two pairwise differences, or at least three pairwise differences between the pairs of magnetic field components, and to determine and output at least one value, or at least two values, or at least three values ​​related to the position of the magnet relative to the sensor device, or to the force or pressure exerted on the flexible material based on (e.g., according to) the one or more pairwise differences.

[0328] The force sensor device can be configured to determine the at least one physical quantity or the at least two physical quantities using one or more predefined functions. The function or functions can be stored in the non-volatile memory of the processing circuit, for example, in the form of a mathematical formula (e.g., as a polynomial expression with multiple coefficients (e.g., with 3 to 30 coefficients (e.g., with at least 3 or at least 4 or at least 6 or at least 8 or at least 12 coefficients)); or in the form of a sum with 3 to 15 terms (e.g., with at least 3 terms, or at least 4 terms, or at least 6 terms, or at least 8 terms, or at least 10 terms, or at least 12 terms); or in the form of a lookup table. The non-volatile memory of the processing circuit. Some of the terms may be the square of the magnetic field difference, or may be the cross product of two magnetic field differences obtained from a pair of sensors spaced apart in the same direction, or may be the cross product of two magnetic field differences obtained from a pair of sensors spaced apart in different directions.

[0329] The coefficients or parameters can be determined using machine learning. Alternatively, the coefficients or parameters can be determined using classical techniques (such as, for example, using curve fitting techniques, linear regression or nonlinear regression techniques, or linear or nonlinear models). It is worth noting that "machine learning" or "deep learning" is usually used for "neural networks" with "hidden layers" and usually requires much more calculations than classical curve fitting techniques.

[0330] A block diagram similar to that of Figures 22(a) and 22(b) may be applicable, where blocks 2226 ("Feature Expansion and Polynomial Expansion") and 2230 ("Weights and Biases") are replaced by the predefined function (e.g., the polynomial, or the lookup table).

[0331] The force sensor device can have Figure 23(a) to Figure 23(e) The appearance shown in , but of course, the present invention is not limited to this.

[0332] The force sensor device may have, for example, three 1D pixels, or four 1D pixels (e.g., as Figure 6 ), or three 2D pixels (e.g., as shown in Figure 4 ), or four 2D pixels (e.g., as shown in Figure 5or Figure 7(a) or Figure 7(b) or Fig.12 or Figure 17(a) or Figure 17(b) or Fig.18 ), or five 2D pixels (e.g., as shown in Figure 8 ), or nine 2D pixels (e.g., as shown in Fig. 9 or Fig.10 ), or eight 2D pixels (e.g., as shown in FIG. 11( a) ), or four 2D pixels and one 3D pixel (e.g., as shown in FIG. Fig.13 ), or four 3D pixels (e.g., as shown in FIG. 14( a) or FIG. 14( b) or FIG. 19( a) or FIG. 19( b)), or five 3D pixels (e.g., as shown in FIG. 15( a) or FIG. 15( b)), or nine 3D pixels (e.g., as shown in FIG. Fig.16 ).

[0333] In a preferred embodiment, at least two pairwise differences are determined, or at least three pairwise differences are determined, or at least four pairwise differences are determined, or at least six pairwise differences are determined, or at least eight pairwise differences are determined, and (one or more) output values ​​are determined based on these pairwise differences.

[0334] Many variations of the force sensor device are envisaged, which are similar to those described above. For example, the force sensor device may further include a temperature sensor, and the temperature may be taken into account in the calculations and / or may be used to correct for temperature-dependent material properties of the elastomer.

Claims

1. A force sensor system comprising a magnetic sensor system, the magnetic sensor system comprising: an integrated circuit comprising a semiconductor substrate comprising a plurality of magnetic sensors configured to measure at least two first magnetic field components oriented in a first direction and to measure at least two second magnetic field components oriented in a second direction; a magnet movable relative to the integrated circuit and configured to generate a magnetic field; as well as a processing circuit configured to determine at least two physical quantities related to the position of the magnet using a predefined algorithm based on the measured first and second magnetic field components or values ​​derived therefrom as inputs and using at least eight constants determined using machine learning, wherein the magnet is flexibly mounted relative to the integrated circuit by means of a flexible material; Therein, the at least two physical quantities to be determined are two or three force components (Fx, Fy, Fz) of the mechanical force applied on the contact surface of the flexible material.

2. The force sensor system according to claim 1, wherein: The predefined algorithm uses as input at least three or at least four magnetic field differences derived from the at least two first magnetic field components and the at least two second magnetic field components and uses the at least eight constants.

3. The force sensor system according to claim 1, in, The semiconductor substrate further includes a temperature sensor for measuring the temperature of the semiconductor substrate, and wherein the semiconductor substrate is configured to correct the measured first magnetic field component and the second magnetic field component based on the measured temperature, or wherein the predefined algorithm takes the measured temperature into account as an additional input, or wherein the measured temperature is used in a post-processing step.

4. The force sensor system according to claim 1, in, Each of the first direction and the second direction is parallel to the semiconductor substrate; or The first direction is parallel to the semiconductor substrate, and the second direction is perpendicular to the semiconductor substrate.

5. The force sensor system according to claim 1, in, The plurality of sensors includes at least one sensor including an integrated magnetic concentrator disk and three pairs of horizontal Hall elements arranged about a periphery of the disk, the Hall elements being angularly spaced a multiple of 120°; or wherein the plurality of sensors comprises at least one sensor comprising an integrated magnetic concentrator disk and four pairs of horizontal Hall elements arranged about a periphery of the disk, the Hall elements being angularly spaced at multiples of 45°; or wherein the semiconductor substrate includes a plurality of magnetic sensors located at intersections of a 2×2 grid, or located at intersections of a 3×3 grid, or located at intersections of a 4×4 grid; or wherein the semiconductor substrate comprises a plurality of magnetic sensors arranged in an irregular pattern; or Wherein, at least three of the magnetic sensors are located on a virtual circle.

6. The force sensor system according to claim 1, in, The semiconductor substrate includes a plurality of magnetic sensors arranged at pseudo-random positions.

7. The force sensor system according to claim 1, in, The magnet is a two-pole magnet; and / or The magnet is an axially magnetized annular or disc-shaped magnet.

8. The force sensor system according to claim 1, in, The predefined algorithm is configured for deriving at least three first difference values ​​from the at least two first magnetic field components, and for deriving at least three second difference values ​​from the at least two second magnetic field components; and Used to calculate the two or three force components based on the at least three first differences and the at least three second differences.

9. The force sensor system according to claim 8, in, Each of the at least three first difference values ​​is determined as a pairwise difference between two first magnetic field components, and wherein each of the at least three second difference values ​​is determined as a pairwise difference between two second magnetic field components; or wherein each of the at least three first difference values ​​is determined as a difference between a first magnetic field component and a first common value, and Therein, each of the at least three second difference values ​​is determined as a difference between the second magnetic field component and the second common value.

10. The force sensor system according to claim 8, in, The predefined algorithm is configured to calculate each of the two or three force components as a sum of at least twelve terms, and Each of the at least twelve items is a function of one or more of the at least three first differences and the at least three second differences.

11. The force sensor system according to claim 10, in, Each of the sums includes a constant value determined by machine learning.

12. The force sensor system according to claim 10, in, The predefined algorithm is configured to calculate each of the two or three force components as a sum of at least twelve terms, wherein at least two of the two terms contain linear expressions of only one of the at least three first differences and the at least three second differences; and Among them, at least two items include nonlinear expressions of one or more of the at least three first differences and the at least three second differences.

13. The force sensor system according to claim 10, in, At least two terms or each sum is a quadratic expression or a second-order polynomial of only one of the at least three first differences and the at least three second differences, or at least two terms or each sum contains a quadratic expression or a second-order polynomial of only one of the at least three first differences and the at least three second differences; and / or wherein each sum comprises at least one term which is a product of the at least three first differences and two of the at least three second differences; and / or wherein each sum comprises at least one term that is a division of two of the at least three first differences and the at least three second differences.

14. The force sensor system according to claim 1, in, The predefined algorithm is executed by a trained neural network, using at least two first magnetic field components and at least two second magnetic field components as input signals; and The two or three force components are provided as output values.

15. The force sensor system of claim 1, wherein: The flexible material is an elastomer.

16. The force sensor system according to claim 1, in, The predefined algorithm further comprises a post-processing step in which the temperature of the flexible material is measured or estimated, and The determined physical quantities are corrected in order to reduce temperature-dependent material properties.

17. A magnetic sensor system comprising: an integrated circuit comprising a semiconductor substrate comprising a plurality of magnetic sensors configured to measure at least two first magnetic field components oriented in a first direction and to measure at least two second magnetic field components oriented in a second direction; a magnet movable relative to the integrated circuit and configured to generate a magnetic field; a processing circuit configured to determine at least two physical quantities related to the position of the magnet using a predefined algorithm based on the measured first and second magnetic field components or values ​​derived therefrom as inputs and using at least eight constants determined using machine learning, Wherein, the predefined algorithm is configured to: deriving at least three first differences from the at least two first magnetic field components and deriving at least three second differences from the at least two second magnetic field components; and calculating the at least two physical quantities based on the at least three first differences and the at least three second differences; wherein each of the at least three first difference values ​​is determined as a pairwise difference between two first magnetic field components, and wherein each of the at least three second difference values ​​is determined as a pairwise difference between two second magnetic field components; or wherein each of the at least three first difference values ​​is determined as a difference between a first magnetic field component and a first common value, and Therein, each of the at least three second difference values ​​is determined as a difference between the second magnetic field component and the second common value.

18. The magnetic sensor system according to claim 17, wherein: The predefined algorithm uses as input the at least three first differences derived from the at least two first magnetic field components and the at least three second differences derived from the at least two second magnetic field components and uses the at least eight constants for determining the at least two physical quantities.

19. The magnetic sensor system according to claim 17, in, The semiconductor substrate further includes a temperature sensor for measuring the temperature of the semiconductor substrate, and wherein the semiconductor substrate is configured to correct the measured first magnetic field component and the second magnetic field component based on the measured temperature, or wherein the predefined algorithm takes the measured temperature into account as an additional input, or wherein the measured temperature is used in a post-processing step.

20. The magnetic sensor system according to claim 17, in, Each of the first direction and the second direction is parallel to the semiconductor substrate; or The first direction is parallel to the semiconductor substrate, and the second direction is perpendicular to the semiconductor substrate.

21. The magnetic sensor system according to claim 17, in, The plurality of sensors includes at least one sensor including an integrated magnetic concentrator disk and three pairs of horizontal Hall elements arranged about a periphery of the disk, the Hall elements being angularly spaced a multiple of 120°; or wherein the plurality of sensors comprises at least one sensor comprising an integrated magnetic concentrator disk and four pairs of horizontal Hall elements arranged about a periphery of the disk, the Hall elements being angularly spaced at multiples of 45°; or wherein the semiconductor substrate includes a plurality of magnetic sensors located at intersections of a 2×2 grid, or located at intersections of a 3×3 grid, or located at intersections of a 4×4 grid; or wherein the semiconductor substrate comprises a plurality of magnetic sensors arranged in an irregular pattern; or Wherein, at least three of the magnetic sensors are located on a virtual circle.

22. The magnetic sensor system according to claim 17, in, The semiconductor substrate includes a plurality of magnetic sensors arranged at pseudo-random positions.

23. The magnetic sensor system according to claim 17, in, The magnet is a two-pole magnet; and / or The magnet is an axially magnetized annular or disc-shaped magnet.

24. A magnetic sensor system comprising: an integrated circuit comprising a semiconductor substrate comprising a plurality of magnetic sensors configured to measure at least two first magnetic field components oriented in a first direction and to measure at least two second magnetic field components oriented in a second direction; a magnet movable relative to the integrated circuit and configured to generate a magnetic field; a processing circuit configured to determine at least two physical quantities related to the position of the magnet using a predefined algorithm based on the measured first and second magnetic field components or values ​​derived therefrom as inputs and using at least eight constants determined using machine learning, Wherein, the predefined algorithm is configured to: deriving at least two first differences from the at least two first magnetic field components and deriving at least two second differences from the at least two second magnetic field components; and calculating the at least two physical quantities based on the at least two first differences and the at least two second differences; wherein the predefined algorithm is configured to calculate each of the at least two physical quantities as a sum of at least twelve terms, and Each of the at least twelve items is a function of one or more of the at least two first differences and the at least two second differences.

25. The magnetic sensor system of claim 24, wherein: Each of the sums includes a constant value determined by machine learning.

26. The magnetic sensor system of claim 24, wherein: The predefined algorithm uses as input the at least two first differences derived from the at least two first magnetic field components and the at least two second differences derived from the at least two second magnetic field components and uses the at least eight constants for determining the at least two physical quantities.

27. The magnetic sensor system according to claim 24, in, The semiconductor substrate further includes a temperature sensor for measuring the temperature of the semiconductor substrate, and wherein the semiconductor substrate is configured to correct the measured first magnetic field component and the second magnetic field component based on the measured temperature, or wherein the predefined algorithm takes the measured temperature into account as an additional input, or wherein the measured temperature is used in a post-processing step.

28. The magnetic sensor system according to claim 24, in, Each of the first direction and the second direction is parallel to the semiconductor substrate; or The first direction is parallel to the semiconductor substrate, and the second direction is perpendicular to the semiconductor substrate.

29. The magnetic sensor system according to claim 24, in, The plurality of sensors includes at least one sensor including an integrated magnetic concentrator disk and three pairs of horizontal Hall elements arranged about a periphery of the disk, the Hall elements being angularly spaced a multiple of 120°; or wherein the plurality of sensors comprises at least one sensor comprising an integrated magnetic concentrator disk and four pairs of horizontal Hall elements arranged about a periphery of the disk, the Hall elements being angularly spaced at multiples of 45°; or wherein the semiconductor substrate includes a plurality of magnetic sensors located at intersections of a 2×2 grid, or located at intersections of a 3×3 grid, or located at intersections of a 4×4 grid; or wherein the semiconductor substrate comprises a plurality of magnetic sensors arranged in an irregular pattern; or Wherein, at least three of the magnetic sensors are located on a virtual circle.

30. The magnetic sensor system according to claim 24, in, The semiconductor substrate includes a plurality of magnetic sensors arranged at pseudo-random positions.

31. The magnetic sensor system according to claim 24, in, The magnet is a two-pole magnet; and / or The magnet is an axially magnetized annular or disc-shaped magnet.

Images