Magnetic position sensor system and method

Abstract

This application discloses a magnetic position sensor system and method. A position sensor system includes: a magnetic field source for generating a magnetic field, and a position sensor device movable relative to the magnetic field source, or vice versa. The position sensor device includes at least three magnetic sensor elements for measuring at least three magnetic field values ​​and processing circuitry for determining at least two magnetic field gradients or magnetic field differences based on the at least three magnetic field values. The processing circuitry is used to derive a first value indicating the position of the position sensor device from the at least two magnetic field gradients or differences, and to derive a second value indicating the integrity of the position sensor system from the at least two magnetic field gradients or differences.

Description

Technical Field

[0001] This invention generally relates to the field of magnetic sensor devices, systems and methods, and more specifically to magnetic position sensor systems, apparatus and methods that can not only determine linear or angular position, but also provide signals indicating system integrity or faults. Background Technology

[0002] Magnetic position sensor systems, particularly linear and angular position sensor systems, are known in the art. They offer the advantage of measuring linear or angular position without physical contact, thus avoiding problems such as mechanical wear, scratches, and friction.

[0003] There are many variations of position sensor systems that address one or more of the following requirements: using simple or inexpensive magnetic structures, using simple or inexpensive sensor devices, being able to measure over a relatively large area, being able to perform high-precision measurements, requiring only simple computation, being able to perform high-speed measurements, being highly robust to positioning errors, being highly robust to external interference fields, providing redundancy, being able to detect errors, being able to detect and correct errors, and having a good signal-to-noise ratio (SNR), etc.

[0004] This invention relates primarily to position sensor systems used in harsh environments, such as, for example, automotive, industrial, and robotic applications, where the main function of the sensor system is to determine linear or angular position even in the presence of electromagnetic interference signals, and where fault detection is an important supporting function to ensure functional safety. Summary of the Invention

[0005] The purpose of this invention is to provide a magnetic position sensor system including a magnetic source and a sensor device, which can provide position information and fault information (or integrity information) in a manner insensitive to external interference fields.

[0006] A specific objective of embodiments of the present invention is to provide a magnetic position sensor system capable of detecting fault conditions (e.g., those related to the mechanical installation of a magnetic source).

[0007] The purpose of certain embodiments of the present invention is to provide such systems including a magnetic source, wherein a sensor device is capable of detecting the presence of the magnetic source.

[0008] The object of a particular embodiment of the present invention is to provide an angular position sensor system comprising a permanent magnet rotatable about a rotation axis, wherein the sensor device preferably has a measurement range of 360° or 180°.

[0009] The purpose of a particular embodiment of the present invention is to provide a linear position sensor system comprising an elongated magnetic structure.

[0010] The purpose of this invention is to provide a system in which the determination of faults or system integrity requires less processing power or only simple arithmetic.

[0011] These and other objectives are achieved through the systems, devices, and methods provided by this invention.

[0012] According to a first aspect, the present invention provides a position sensor system comprising: a magnetic field source for generating a magnetic field; and a position sensor device movable relative to the magnetic field source, or vice versa, the position sensor device comprising: at least three magnetic sensing elements for measuring at least three magnetic field values ​​of the magnetic field; and a processing circuit configured to acquire the at least three magnetic field values ​​and determine at least two magnetic field gradients or at least two magnetic field differences based on the at least three magnetic field values, and to derive from the at least two magnetic field gradients or the at least two magnetic field differences a first signal (first value) indicating the position (e.g., linear or angular position) of the magnetic source relative to the position sensor device (or vice versa); wherein the processing circuit is further configured to derive from the at least two magnetic field gradients or the at least two magnetic field differences a second signal indicating a fault (e.g., electrical fault and / or mechanical fault) or integrity of the position sensor system.

[0013] Fault signals (or integrity signals) can, for example, indicate the presence of a magnetic source.

[0014] The main advantage of determining relative position based on magnetic field gradient or magnetic field difference is that such positions are highly insensitive to external disturbance fields.

[0015] The main advantage of this system is that it not only provides a first signal (or first value) indicating position (e.g., linear or angular), but also a second signal indicating faults, because in this way certain problems (e.g., electrical defects and / or mechanical defects, such as defective Hall elements or damaged magnets) can be detected, and the entire system using this position sensor system can become safer.

[0016] To the inventor's knowledge, in the prior art, magnetic field gradients or magnetic field differences are not used for fault detection or verification of electrical, mechanical, or system integrity.

[0017] The integrity signal itself is also highly insensitive to external disturbance fields due to the main advantage of being based on magnetic field gradient or magnetic field difference.

[0018] This system is ideally suited for use in harsh environments, such as, for example, automotive, industrial, or robotic environments.

[0019] In the embodiments, at each sensor location, only a single magnetic field component (e.g., Bz perpendicular to the semiconductor substrate orientation) is measured (see, for example, Figures 1 through 4 and...). Figure 14 (a) to Figure 16 (d)).

[0020] In an embodiment, the two orthogonal magnetic field components (e.g., Bx and Bz, or Bx and By) are at two different sensor locations (see, for example, Figures 5 to 11 Each of the sensors is measured, for example, the first sensor position and the second sensor position, which are preferably spaced at least 1.0 mm apart, for example, from about 1.5 mm to about 2.5 mm, for example, a distance of about 2.0 mm.

[0021] The sensor device may also be configured to provide the first signal or value as a position signal and to provide the second signal or value (or a value derived therefrom) as an integrity signal and / or a warning signal and / or an error signal.

[0022] In an embodiment, the position sensor device is further configured to output the first signal indicating a relative position, and to output the second signal or a signal derived therefrom as a separate signal.

[0023] In an embodiment, a first signal (e.g., as a digital or analog signal) is provided on a first output port, and a second signal (e.g., as a digital or analog signal) is provided on a second output port different from the first output port.

[0024] In one embodiment, the first signal and the second signal are provided as separate values ​​in the serial bit stream.

[0025] In one embodiment, the sensor device may be movable relative to the magnetic source.

[0026] In this embodiment, the magnetic source can be movable relative to the sensor device. For example, the magnetic source can be mounted on a rotatable shaft, and the sensor device can be mounted on a stator or frame.

[0027] In one embodiment, the sensor device includes at least three magnetic sensor elements oriented in a single direction; and the processing circuit is configured to determine at least three magnetic field differences based on the at least three magnetic field values ​​and derive the first signal from the at least three magnetic field differences; and to derive the second signal from the at least three magnetic field differences.

[0028] In one embodiment, the sensor device is further configured to determine the second signal as a polynomial expression of the at least two magnetic field gradients, the polynomial expression having at least two orders.

[0029] In an embodiment, the sensor device is further configured to determine the second signal as a polynomial expression of the at least two or the at least three magnetic field differences, the polynomial expression having at least two orders, for example, the sum of the squares of the differences.

[0030] These coefficients can be predetermined during the design phase, or determined and written into non-volatile memory (e.g., flash memory) embedded in the sensor device during calibration testing, and can be read from the non-volatile memory during actual use of the device.

[0031] In an embodiment, the polynomial expression is a second-order polynomial with non-zero first-order terms, for example, according to the following formula: Second signal = A*sqr(gradient 1) + B*sqr(gradient 2) + C*(gradient 1*gradient 2) + D*(gradient 1) + E*(gradient 2) + F, where gradient 1 is a first gradient derived from the at least three magnetic field values, and gradient 2 is a second gradient derived from the at least three magnetic field values ​​that is different from the first gradient, and A, B, C, D, E, and F are constant values, for example, predetermined values. Each of the values ​​A and B is different from zero. The values ​​C, D, E, and F may be equal to zero or may be different from zero.

[0032] In a particular embodiment, the values ​​C, D, and E are equal to zero.

[0033] In a particular embodiment, the values ​​C and D, and E and F are equal to zero.

[0034] In the embodiments, the polynomial expression is a third-order polynomial or a fourth-order polynomial.

[0035] In the embodiment, the coefficients of the polynomial expression are selected such that, regardless of the relative position, the second signal is substantially constant (within a predefined tolerance margin of ±25%, or ±20%, or ±15%, or ±10%, or ±5%) for the intended (effective) position in the correct mechanical mounting system.

[0036] In one embodiment, the sensor device is further configured to determine the second signal as the sum of the absolute values ​​of the at least two or the at least three magnetic field gradients.

[0037] In an embodiment, the sensor device is further configured to determine the second signal as the sum of the absolute values ​​of the at least two or the at least three differences.

[0038] In an embodiment, the second signal is selected such that the second signal is substantially independent of its relative position over the entire measurement range.

[0039] "Substantially constant" means within a relatively small range around a predefined value, for example, within ±25% of the predefined value, or within ±20% of the predefined value, or within ±15% of the predefined value, or within ±10% of the predefined value, or within ±5% of the predefined value, or even within ±2% of the predefined value.

[0040] The advantage of this embodiment is that the second signal is essentially constant for any position of the sensor device relative to the magnetic source, as it allows for checking the integrity of the mechanical installation (in particular), for example, detecting mechanical installation problems, without knowing or considering the actual position.

[0041] In an embodiment, the sensor device is further configured to compare the second signal with at least one threshold and to provide an output signal (e.g., a warning signal and / or an error signal) corresponding to the result of the at least one comparison.

[0042] In one embodiment, the position sensor system is connected to an external processor and configured to provide a second signal (or a value derived therefrom) to the external processor, and the external processor is configured to compare the second signal with at least one threshold.

[0043] In this embodiment, the actual comparison is performed outside the sensor device, for example, in an external processor, such as in an ECU.

[0044] In one embodiment, the position sensor system is connected to an external processor and configured to provide the external processor with the at least two gradient values ​​or the at least two gradient signals or the at least two or at least three magnetic field differences, and the external processor is configured to calculate a second signal based on the at least two gradients or the at least two or at least three differences.

[0045] In this embodiment, the actual calculation of the second signal is performed outside the sensor device, for example, in an external processor, such as in an ECU.

[0046] In an embodiment, the position sensor device is configured to output a first signal indicating a relative position, and is further configured to compare a second signal with a first threshold (T1) and a second threshold (T2), and to provide a second output signal indicating whether the second signal is a value between the first threshold and the second threshold.

[0047] In the embodiments (for example, as shown in Figures 1 to 4 or...), Figure 14 (a) to Figure 16 (d) shows that the magnetic field source is a permanent magnet (e.g., a toroidal magnet or a disk magnet) rotatable about a rotation axis; and the sensor device is configured to determine an angular position and is substantially located on the axis. Such a mechanical arrangement is also referred to herein as an "on-axis" arrangement.

[0048] In an embodiment, the magnetic field source is a permanent magnet having at least four poles (e.g., an axially magnetized four-pole, six-pole, or eight-pole disk magnet, or an axially magnetized four-pole, six-pole, or eight-pole toroidal magnet), and the sensor device includes a semiconductor substrate substantially orthogonal to the axis of rotation, the semiconductor substrate including a plurality of at least four pairs of sensor elements, each pair being configured to measure magnetic field values ​​(e.g., Bx, By, Bu, Bv) in different directions (e.g., X, Y, U, U) parallel to the substrate; and the sensor device is further configured to determine at least four magnetic field gradients or magnetic field differences associated with the at least four pairs of signals.

[0049] The second signal can be a polynomial expression of two different linear combinations of the at least four magnetic field gradients or differences (or values ​​derived therefrom).

[0050] The second signal may be a weighted sum of the squares of two different linear combinations of the at least four magnetic field gradients or differences (or values ​​derived therefrom).

[0051] In one embodiment, the at least eight sensor elements are located on a virtual circle.

[0052] In this embodiment, the magnetic field source is a permanent magnet with four poles (e.g., an axially magnetized quadrupole disk magnet or an axially magnetized quadrupole ring magnet), and the semiconductor substrate includes at least eight sensor elements located on a virtual circle; and the sensor device is configured to define at least four magnetic field gradients (e.g., dBx / dy, dBy / dx, dBu / dv, dBv / du) along at least four different directions parallel to the substrate and spaced 45° apart at angles; and calculate a second signal according to the following formula:

[0053] Signal 2 = (dBx / dx - dBy / dy) 2 Or according to the following formula:

[0054] Signal 2 = (dBu / du - dBv / dv) 2 +(dBx / dx-dBy / dy) 2 , or values ​​derived from it.

[0055] In an embodiment (e.g., as shown in FIG4(c)), the magnetic field source is a bipolar permanent magnet (e.g., a bar magnet or a radially magnetized bipolar disk magnet, or a radially magnetized bipolar ring magnet, or an axially magnetized bipolar disk magnet, or an axially magnetized bipolar ring magnet), and the sensor device includes: a semiconductor substrate substantially orthogonal to the axis of rotation, the semiconductor substrate including at least three or at least four sensor elements, each sensor element being configured to measure a magnetic field component (e.g., Bz) oriented in a direction substantially perpendicular to the semiconductor substrate; and the sensor device is further configured to determine two magnetic field gradients (e.g., dBz / dx; dBz / dy) of the magnetic field value (e.g., Bz) along two orthogonal directions (e.g., X, Y) parallel to the semiconductor substrate.

[0056] The second signal can be determined as a weighted sum of the squares of these gradients.

[0057] In one embodiment (for example, as shown in FIG4(b)), the semiconductor substrate includes four horizontal Hall elements without an IMC (Integrated Magnetic Concentrator) located on a virtual circle, the four horizontal Hall elements being 90° apart angularly.

[0058] In an embodiment (for example, as shown in FIG4(c)), the semiconductor substrate includes three or only three horizontal Hall elements without an IMC (Integrated Magnetic Concentrator), two of which are located on a virtual circle, spaced 90° apart, and one of which is located at the center of the virtual circle, thereby forming an L-shape or a right triangle.

[0059] In this embodiment, the second signal is the sum or weighted sum of the squares of these magnetic field gradients, or a value derived therefrom. For example, the sum can be expressed mathematically as: Signal2 = (dBz / dx) 2 +(dBz / dy) 2 For example, the weighted sum can be written as: signal2 = A(dBz / dx) 2 +B.(dBz / dy) 2 .

[0060] The sensor device can further test whether the sum is within a predefined range, or it can, for example, calculate the square root of the sum and test whether the square root is less than a first threshold or greater than a second threshold.

[0061] In the embodiments (see, for example, Figures 5 to 10 The magnetic field source is a permanent magnet rotatable about a rotation axis; and the sensor device is configured to determine an angular position and is located at a non-zero distance from the rotation axis. For example, the sensor device can be positioned such that its magnetic center is located at a distance of at least 3 mm or at least 4 mm from the rotation axis.

[0062] In the embodiments (see, for example, Figure 5 The magnetic field source is a bipolar permanent magnet (e.g., a diameter-magnetized bipolar disk magnet, a diameter-magnetized bipolar ring magnet, an axially magnetized bipolar disk magnet, or an axially magnetized bipolar ring magnet), and the sensor device is configured to measure a first magnetic field component (e.g., Bx) oriented in a circumferential direction (e.g., X) about the rotation axis, and a second magnetic field component (e.g., By) oriented in a radial direction (e.g., Y) relative to the rotation axis; and the sensor device is configured to determine a first magnetic field gradient (e.g., dBx / dx) of the first magnetic field component (e.g., Bx) along the circumferential direction (e.g., X), and to determine a second magnetic field gradient (e.g., dBy / dx) of the second magnetic field component (e.g., By) along the circumferential direction (e.g., X); and the sensor device is further configured to calculate a second signal as a function of the first magnetic field gradient and the second magnetic field gradient, for example, as the sum of the squares of these second magnetic field gradients.

[0063] In embodiments (e.g., such as) Figure 5 and Figure 8 As shown), the permanent magnet is a ring-shaped magnet with an inner radius (Ri) and an outer radius (Ro), and the positioning sensor device is positioned such that its magnetic core is located at a distance (Rs) between the inner radius and the outer radius, for example, essentially in the middle between the inner radius and the outer radius.

[0064] In embodiments (e.g., as shown in the example) Figure 6 or Figure 7 As shown in the diagram, the magnetic field source is a bipolar permanent magnet (e.g., a diameter-magnetized bipolar disk magnet, a diameter-magnetized bipolar ring magnet, an axially magnetized bipolar disk magnet, or an axially magnetized bipolar ring magnet), and the sensor device is configured to measure a first magnetic field component (e.g., Bx) oriented in a circumferential direction (e.g., X) about the rotation axis, and a second magnetic field component (e.g., Bz) oriented in a direction parallel to the rotation axis (e.g., Z); and wherein the sensor device is configured to determine a first magnetic field gradient (e.g., dBx / dx) of the first magnetic field component (e.g., Bx) along the circumferential direction (e.g., X), and to determine a second magnetic field gradient (e.g., dBz / dx) of the second magnetic field component (e.g., Bz) along the circumferential direction (e.g., X); and the sensor device is further configured to calculate the second signal as a function of the first and second magnetic field gradients, for example, as the sum or weighted sum of the squares of these magnetic field gradients.

[0065] In an embodiment, the permanent magnet has an outer radius (Ro), and the positioning sensor device is positioned such that its magnetic center is located at a distance (Rs) within the range of 80% to 120% of the outer radius, or within the range of 90% to 110% of the outer radius, or within the range of 95% to 105% of the outer radius.

[0066] In embodiments (e.g., as shown in the example) Figure 8 As shown in the diagram, the magnetic field source is a permanent magnet having at least four poles (e.g., an axially magnetized four-pole, six-pole, or eight-pole disk magnet, or an axially magnetized four-pole, six-pole, or eight-pole toroidal magnet), and the sensor device is configured to measure a first magnetic field component (e.g., Bx) oriented in a circumferential direction (e.g., X) relative to the rotation axis, and a second magnetic field component (e.g., Bz) oriented in a direction parallel to the rotation axis (e.g., Z); and the sensor device is configured to determine a first magnetic field gradient (e.g., dBx / dx) of the first magnetic field component (e.g., Bx) along the circumferential direction (e.g., X), and to determine a second magnetic field gradient (e.g., dBz / dx) of the second magnetic field component (e.g., Bz) along the circumferential direction (e.g., X); and the sensor device is further configured to calculate the second signal as a function of the first and second magnetic field gradients, for example, as a sum or weighted sum of the squares of these magnetic field gradients.

[0067] In embodiments (e.g., such as) Figure 9 and Figure 10 As shown in the diagram, the magnetic field source is a permanent magnet having at least four poles (e.g., an axially magnetized four-pole, six-pole, or eight-pole disk magnet, or an axially magnetized four-pole, six-pole, or eight-pole toroidal magnet), and the sensor device is configured to measure a first magnetic field component (e.g., Bx) oriented in a circumferential direction (e.g., X) relative to the axis of rotation, and a second magnetic field component (e.g., Br) oriented in a radial direction relative to the permanent magnet; and the sensor device is configured to determine a first magnetic field gradient (e.g., dBx / dx) of the first magnetic field component (e.g., Bx) along the circumferential direction (e.g., X), and to determine a second magnetic field gradient (e.g., dBr / dx) of the second magnetic field component (e.g., Br) along the circumferential direction (e.g., X); and the sensor device is further configured to calculate the second signal as a function of the first and second magnetic field gradients, for example, as the sum or weighted sum of the squares of these magnetic field gradients.

[0068] In this embodiment, the permanent magnet has an outer radius (Ro), and the positioning sensor device is positioned such that its magnetic center is located at a distance (Rs) within the range of 105% to 200% of the outer radius, or within the range of 105% to 150% of the outer radius, or within the range of 105% to 140% of the outer radius. Furthermore, in this embodiment, the sensor device is preferably located at an axial position substantially midway between the bottom and top surfaces of the permanent magnet.

[0069] In embodiments (e.g., such as) Figure 11 As shown), the magnetic field source is a magnetic structure having an elongated shape extending in a first direction (e.g., X) and having a plurality of at least two, at least three, or at least four magnetic poles magnetized in a second direction (e.g., Z) substantially perpendicular to the first direction (e.g., X); and the sensor device is movable relative to the magnetic structure in the first direction (e.g., X), or vice versa, and is configured to determine a linear position in the first direction (e.g., X); and the distance between the sensor device and the magnetic structure (measured in the second direction (e.g., Z)) is substantially constant; and wherein the sensor device is respectively configured to measure a first magnetic field component (e.g., Bx) oriented in the first direction (e.g., X) and a second magnetic field component (e.g., Bz) oriented in the second direction (e.g., Z); and the sensor device is configured to determine a first magnetic field gradient (e.g., dBx / dx) of the first magnetic field component (e.g., Bx) along the first direction (e.g., X), and to determine a second magnetic field gradient (e.g., dBx / dx) of the second magnetic field component (e.g., Bz) along the first direction (e.g., X). dBz / dx); and the sensor device is configured to calculate the second signal as a function of the first magnetic field gradient and the second magnetic field gradient, for example, as the sum or weighted sum of the squares of these magnetic field gradients.

[0070] Preferably, the magnetic structure has a plane of symmetry parallel to a first direction (e.g., X) and a second direction (e.g., Z), and preferably, the sensor device is positioned such that its magnetic center is substantially located in this plane of symmetry.

[0071] According to another aspect, the present invention also relates to sensor devices for use in any of the above-described position sensor systems, for example, for use in automotive, industrial, or robotic environments.

[0072] According to another aspect, the present invention also provides a method for determining location and determining fault or integrity of a sensor system according to the first aspect. The method includes the steps of: a) measuring at least three magnetic field values ​​of the magnetic field; b) determining at least two magnetic field gradients, or at least two or at least three magnetic field differences, based on the at least three magnetic field values; c) deriving a first signal indicating the location of the sensor device from the at least two magnetic field gradients or from the at least two or at least three magnetic field differences; and d) deriving a second signal indicating a fault or indicating the integrity of the location sensor system (e.g., indicating the presence of a magnetic source near the sensor device) from the at least two magnetic field gradients or from the at least two or at least three magnetic field differences.

[0073] This method is ideally suited for use in harsh environments, such as, for example, automotive, industrial, or robotic environments.

[0074] The method may further include the steps of providing the first signal as a first output signal and providing the second signal as a second output signal. The first and second output signals may be analog signals or digital signals, or one signal may be a digital signal and the other signal may be an analog signal.

[0075] In an embodiment, step d) includes: determining the second signal as a polynomial expression of the at least two magnetic field gradients, for example, as the sum or weighted sum of the squares of the gradient signals, or the sum of the squares of the difference signals, or the sum of the absolute values ​​of the difference signals.

[0076] The method may further include the step of retrieving the coefficients of the polynomial expression from non-volatile memory.

[0077] The method may further include step e): comparing the second signal with at least one threshold or at least two thresholds; and outputting at least one signal (e.g., a warning signal and / or an error signal) corresponding to the result of the at least one comparison or the at least two comparisons.

[0078] Specific and preferred aspects of the invention are set forth in the appended independent and dependent claims. Features from the dependent claims may be suitably combined with features of the independent claims and other dependent claims, and not merely as expressly set forth in the claims. These and other aspects of the invention will be apparent from the embodiments(s) described herein, and are illustrated with reference to these embodiments. Attached Figure Description

[0079] Figure 1(a) illustrates an angular position sensor system according to an embodiment of the present invention. The position sensor system includes a quadrupole magnet rotatable about a rotation axis, and a sensor device located in an "on-axis" position having eight horizontal Hall elements and an IMC structure.

[0080] Figure 1(b) shows a graph of the magnitude of the difference between the two gradients in example |dBx / dx-dBy / dy| at various locations near the axis of rotation.

[0081] Figure 2 An angular position sensor system according to another embodiment of the present invention is shown. The position sensor system includes a quadrupole magnet rotatable about a rotation axis, and a sensor device located in an "on-axis" position and having four vertical Hall elements configured to measure the radial magnetic field component.

[0082] Figure 3 An angular position sensor system according to another embodiment of the present invention is shown. The position sensor system includes a quadrupole magnet rotatable about a rotation axis, and a sensor device located in an "on-axis" position and having four vertical Hall elements configured to measure the circumferential magnetic field component (i.e., a field component oriented tangentially to an imaginary circle having a center located on the rotation axis).

[0083] Figures 4(a) and 4(b) illustrate an angular position sensor system according to another embodiment of the present invention. This position sensor system includes a diode magnet rotatable about a rotation axis, and a sensor device located in an "on-axis" position with four horizontal Hall elements but without an IMC (Integrated Magnetic Concentrator).

[0084] Figure 4(c) shows an angular position sensor system according to another embodiment of the present invention, wherein the sensor device 415 has three horizontal Hall elements, two of which are located on a virtual circle and one of which is located at the center of the virtual circle.

[0085] Figure 4(d) shows the simulation results of the sum of the squares of the differences between each of the Hall elements on the circle and the central element, which can be used for fault detection as in the embodiments of the present invention.

[0086] Figure 4(e) shows the simulation results of the sum of the absolute values ​​of the differences between each of the Hall elements on the circle and the central element, which can be used for fault detection as in the embodiments of the present invention.

[0087] Figure 5An angular position sensor system according to another embodiment of the invention is shown. The position sensor system includes a diode magnet rotatable about a rotation axis, and a sensor device located in an "off-axis" position (e.g., above or below the magnet) and configured to measure two circumferential field components and two radial field components. The sensor device has a substrate oriented substantially perpendicular to the rotation axis.

[0088] Figure 6 An angular position sensor system according to another embodiment of the present invention is shown. The position sensor system includes a bipolar magnet rotatable about a rotation axis, and a sensor device located near a “corner” position and configured to measure two circumferential and two axial field components. The sensor device has a substrate oriented substantially perpendicular to the rotation axis.

[0089] Figure 7 An angular position sensor system according to another embodiment of the present invention is shown. The position sensor system includes a magnet rotatable about a rotation axis (e.g., a bipolar or quadrupole magnet, or a magnet with more than four poles), and a sensor device located near a “corner” position and configured to measure two circumferential and two axial field components. The sensor device has a substrate oriented substantially parallel to the rotation axis.

[0090] Figure 8 An angular position sensor system according to another embodiment of the invention is shown. The position sensor system includes a quadrupole magnet rotatable about a rotation axis, and a sensor device located in an "off-axis" position (e.g., above or below the magnet) and configured to measure two circumferential and two axial magnetic field components. The sensor device has a substrate oriented substantially perpendicular to the rotation axis.

[0091] Figure 9 An angular position sensor system according to another embodiment of the invention is shown. The position sensor system includes a quadrupole magnet rotatable about a rotation axis, and a sensor device located in a plane substantially perpendicular to the rotation axis and substantially midway between the top and bottom of the magnet. The sensor device is configured to measure two circumferential magnetic field components and two radial magnetic field components.

[0092] Figure 10 An angular position sensor system according to another embodiment of the present invention is shown. The position sensor system includes a quadrupole magnet rotatable about a rotation axis, and a sensor device having a substrate oriented substantially parallel to the rotation axis and located substantially between the top and bottom surfaces of the magnet. The sensor device is configured to measure two circumferential magnetic field components and two radial magnetic field components.

[0093] Figure 11A linear position sensor system according to another embodiment of the present invention is shown. The position sensor system includes a multipole magnetic structure having an elongated shape extending in a first direction and having a plurality of magnetic poles magnetized in a second direction substantially perpendicular to the first direction, and a sensor device configured to measure two magnetic field components oriented in the first direction and two magnetic field components oriented in the second direction.

[0094] Figure 12 A flowchart is shown of a method for determining a first signal indicating position and a second signal indicating fault or integrity of a position sensor system, wherein both the first and second signals are insensitive to external interference fields.

[0095] Figure 13 This is a schematic block diagram of an exemplary position sensor device according to an embodiment of the present invention.

[0096] Figure 14 (a) and Figure 14 (b) shows another sensor system according to an embodiment of the invention, including a bipolar magnet and a sensor device comprising three horizontal Hall elements located on a virtual circle and angularly spaced in multiples of 120°; Figure 14 (c) shows the simulation results of the sum of squares of the differences between pairs of two magnetic field components; Figure 14 (d) shows the simulation results of the sum of the absolute values ​​of the differences between pairs of two magnetic field components.

[0097] Figure 15 (a) and Figure 15 (b) shows another sensor system comprising a bipolar magnet and a sensor device comprising three horizontal Hall elements located on a virtual circle and spaced apart angularly in multiples of 120°, and a fourth horizontal Hall element located at the center of the circle; Figure 15 (c) shows the simulation results of the sum of the squares of the differences between each of the Hall elements on the circle and the central element; Figure 15 (d) shows the simulation results of the sum of the absolute values ​​of the differences between each of the Hall elements on the circle and the central element.

[0098] Figure 16 (a) and Figure 16 (b) shows another sensor system including a bipolar magnet and a sensor device comprising three horizontal Hall elements located on a virtual circle and spaced apart angularly in multiples of 120°. Figure 16 (c) shows the simulation results of the sum of squares of the differences between each magnetic field component and the average of the three signals; Figure 16(d) shows the simulation results of the sum of the absolute values ​​of the differences between each magnetic field component and the average value of the three signals.

[0099] The accompanying drawings are illustrative only and not restrictive. In the drawings, some elements may be enlarged and drawn off-scale for illustrative purposes. No reference numerals in the claims should be construed as limiting the scope. In different drawings, the same reference numerals refer to the same or similar elements. Detailed Implementation

[0100] The invention will be described with reference to specific embodiments and particular drawings, but the invention is not limited thereto but is defined only by the claims. The described drawings are merely illustrative and not restrictive. In the drawings, some elements may be enlarged and not drawn to scale for illustrative purposes. Scale and relative scale do not correspond to an actual reduction in scale for the practice of the invention.

[0101] Furthermore, the terms first, second, etc., used in the specification and claims are used to distinguish between similar elements and are not necessarily used to describe an order in time, space, rank, or any other way. It should be understood that the terms thus used are interchangeable where appropriate, and the embodiments of the invention described herein can be operated in a different order than that described or explained herein.

[0102] Furthermore, the terms "top," "below," etc., used in the specification and claims are for descriptive purposes and are not necessarily used to describe relative positions. It should be understood that the terms used so are interchangeable where appropriate, and the embodiments of the invention described herein can operate in orientations other than those described or illustrated herein.

[0103] It should be noted that the term "comprising" as used in the claims should not be construed as limiting itself to the devices listed thereafter; it does not exclude other elements or steps. Therefore, the term should be interpreted as specifying the presence of the features, integers, steps, or components stated 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 statement "an apparatus comprising devices A and B" should not be limited to an apparatus consisting solely of components A and B. This means that for the purposes of this invention, the only relevant components of the apparatus are A and B.

[0104] Throughout this specification, the reference to "an embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of the invention. Therefore, the phrase "in one embodiment" or "in an embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, but may refer to the same embodiment. Furthermore, in one or more embodiments, as will be obvious to those skilled in the art from this disclosure, particular features, structures, or characteristics can be combined in any suitable manner.

[0105] Similarly, it should be understood that in the description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, drawing, or description for the purpose of simplifying the disclosure and aiding in the understanding of one or more inventive aspects. However, this method of disclosure should not be construed as reflecting an intention to claim more features than are expressly recited in each claim. Rather, as reflected in the appended claims, inventive aspects exist in fewer features than all the features of a single foregoing disclosed embodiment. Therefore, the claims appended following the detailed description are thus explicitly incorporated into this detailed description, wherein each claim itself represents a separate embodiment of the invention.

[0106] Furthermore, while some embodiments described herein include features that are included in other embodiments but not others, it will be understood by those skilled in the art that combinations of features from different embodiments are intended to fall within the scope of the invention and form different embodiments. For example, any embodiment of the claimed embodiments in the appended claims can be used in any combination.

[0107] Numerous specific details are set forth in the description provided herein. However, it should be understood that embodiments of the invention can be practiced without these specific details. In other instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this description.

[0108] In this document, the terms "magnetic sensor device," "sensor device," or "position sensor device" refer to a device comprising a substrate (preferably a semiconductor substrate) including at least two "magnetic sensor elements." The sensor device may be included in a package (also referred to as a "chip"), but this is not strictly necessary.

[0109] exist Figures 5 to 10In the illustrated embodiments (where the sensor device is not positioned with its magnetic center on the rotation axis), the Bx component typically refers to the magnetic field component oriented in a direction parallel to the direction of motion in the case of a linear position sensor, or, in the case of a curved trajectory, the magnetic field component oriented tangentially to the trajectory of motion, while the By component refers to the magnetic field component parallel to the semiconductor plane perpendicular to the Bx component. In this document, the Bx and By components also refer to "in-plane magnetic field components" because they are oriented parallel to the semiconductor plane of the sensor device. In these embodiments, the Bz component typically refers to the magnetic field component oriented perpendicular to the sensor substrate. In this document, the Bz component also refers to "out-of-plane components".

[0110] In this document, the terms "spatial derivative," "derivative," "spatial gradient," or "gradient" are used as synonyms. In the context of this invention, the gradient is generally determined as the difference between two values ​​obtained from magnetic sensors sensitive in the same direction and spaced apart from each other, or as the sum of the two values ​​if they are obtained from sensor elements sensitive in opposite directions. Therefore, the derivative dBx / dx is typically calculated herein as (Bx1 - Bx2), where Bx1 represents the Bx component measured at a first position, and Bx2 represents the Bx component measured at a second position along the X-axis at a distance "dx" from the first position, but mathematical division by "dx" is generally omitted. Similarly, the derivative dBy / dx is typically calculated as (By1 - By2), where By1 represents the By component measured at a first position, and By2 represents the By component measured at a second position along the X-axis at a distance "dx" from the first position, but mathematical division by "dx" is generally omitted. However, for example in... Figure 2 and Figure 3 In this case, the gradient dBx / dx is calculated as the sum (not the difference) of Vh0 and Vh1, since the vertical Hall elements H0 and H1 are oriented in opposite directions.

[0111] In this document, the terms "first value" and "first signal" are used interchangeably. Similarly, the terms "second value" and "second signal" are used interchangeably.

[0112] In this document, the terms arctan function or atan2 function refer to the arctangent function. Readers unfamiliar with the atan2 function (or the "2-parameter arctangent" function) can refer to, for example, https: / / en.wikipedia.org / wiki / Atan2 for more information. In the context of this invention, the formulas arctan(x / y), atan2(x,y), and arccot(y / x) are considered equivalent.

[0113] In this document, the terms "circumferential direction relative to the axis of rotation," "circumferential direction relative to the magnet," and "direction tangent to a virtual circle having a center on the axis of rotation" are used interchangeably. Figures 5 to 10 In some embodiments, this direction is represented by the X-axis (as seen in sensor devices).

[0114] This invention relates to position sensor systems for harsh environments, such as automotive, industrial, and robotic applications. In such environments, one challenge is obtaining accurate results despite potentially large interference signals. Another challenge relates to functional safety. The design of safety-related applications can be governed by safety standards such as ISO 26262 and IEC 61508.

[0115] More specifically, the present invention proposes a magnetic position sensor system that not only provides an accurate position signal but also a second signal indicating system integrity, or in other words, indicating fault conditions, such as electrical and / or mechanical fault conditions. One such fault condition is magnetic loss, for example, caused by mechanical forces applied to a magnetic source when mounted on a pole.

[0116] To address this problem, the present invention proposes a position sensor system comprising a magnetic field source (e.g., a permanent magnet or permanent magnet structure) and a position sensor device. The magnetic field source is configured to generate a magnetic field. The position sensor device is movable relative to the magnetic field source, or vice versa. The position sensor device includes at least three magnetically sensitive elements for measuring at least three magnetic field values; and processing circuitry configured to determine at least two magnetic field gradients or at least two or at least three magnetic field differences based on the at least three magnetic field values, and to derive from the at least two magnetic field gradients or the at least two or at least three magnetic field differences a first signal indicating the position of the magnetic source relative to the position sensor device (or vice versa), and to further derive from the at least two magnetic field gradients or the at least two or at least three magnetic field differences a second signal indicating a fault condition or integrity, such as the mechanical integrity or mechanical fault condition of the position sensor system, for example, indicating the presence of the magnetic source or indicating mechanical misalignment or physical damage to the magnet.

[0117] Magnetic position systems that use spatial gradients to determine linear or angular positions are known in the art, but to the inventors' knowledge, such systems lack provisions for detecting (e.g., mechanical) fault conditions; for example, either none are specified at all, or there are no provisions for robustness to external disturbance fields. However, the inventors of this invention have surprisingly discovered that gradient signals can also be used to determine mechanical installation problems, such as the loss of a magnetic source.

[0118] A second signal indicating a fault (e.g., system failure) or integrity (e.g., mechanical integrity or system integrity) can be determined as a polynomial expression of the at least two magnetic field gradients or differences, for example, as a second-order function of these gradients or differences. Its advantage is that no angle measurement function is required to calculate such a second signal.

[0119] In a particular embodiment, the second signal is calculated as the sum or weighted sum of the squares of the two gradient or difference signals. In other embodiments (e.g., FIG. 1), the second signal is calculated as the sum of the squares of the first difference between the two gradient signals and the squares of the second difference between the two gradient signals.

[0120] While not absolutely necessary, it is preferable that the second signal is substantially independent of the actual position, or in other words, substantially constant over the envisioned measurement range. This provides, among other things, the advantage that integrity (e.g., mechanical) can be assessed without actually calculating the position, and therefore at a frequency different from the frequency at which the current position is determined.

[0121] Optionally, the position sensor device is further adapted to compare the second signal with one or more predefined thresholds (e.g., hard-coded in a microcontroller or stored in non-volatile memory during production or calibration testing), for example, to test whether the second signal is within a predefined range. The sensor device may be further configured to provide an output signal based on the result of the at least one comparison, for example, indicating a "good condition" (e.g., when the signal has a value within a predefined range between the thresholds) or an "error condition" (e.g., when the signal has a value outside the predefined range, such as greater than an upper threshold or less than a lower threshold).

[0122] As will be further clarified, the basic principles of the present invention are applicable to various mechanical configurations, such as:

[0123] - Angular position sensor systems (see, for example, Figures 1-10) and linear position sensor systems (see, for example, Figure 11 );

[0124] - For various magnetic sources (e.g., two-pole disk magnets or two-pole toroidal magnets, or four-pole disk magnets or four-pole toroidal magnets, or toroidal magnets or disk magnets with more than four poles);

[0125] - For different topologies, such as angular position sensor systems, the sensor devices are mounted at different locations relative to the magnetic source, for example, in so-called "on-axis" locations (see, for example, Figures 1-4), or in so-called "off-axis" locations (see, for example, Figure 5 and Figure 8), or "in the corner" (see, for example, Figure 6 and Figure 7 ), or “outside the magnet” in this text also refers to “near the equator” (see, for example, Figure 9 and Figure 10 );

[0126] - For sensor devices with substrates mounted in various orientations (e.g., parallel to or perpendicular to the axis of rotation);

[0127] For sensor devices with various types of sensor elements, for example, only horizontal Hall elements with IMC (e.g., Figure 1a , Figure 5 c. Figure 6 e Figure 7 d、 Figure 8 c. Figure 8 d、 Figure 9 c. Figure 10d Figure 11 b、 Figure 11 c) Only has a horizontal Hall element without IMC (e.g., Figure 4b Figure 4c Figure 14 (a) Figure 15 (a) Figure 16 (a)) having both a horizontal Hall element and a vertical Hall element (e.g., Figure 6 f、 Figure 8 d、 Figure 10 e Figure 11 c) Only has a vertical Hall element (e.g., Figure 2, Figure 3 , Figure 5 d、 Figure 7 e Figure 9 d) However, other sensor elements, such as magnetoresistive elements (not shown), may also be used.

[0128] Now refer to the attached figures.

[0129] Figure 1(a) illustrates an angular position sensor system 100. This position sensor system includes a quadrupole ring magnet 102 or quadrupole disk magnet rotatable about a rotation axis, and a sensor device 101 located in a so-called “on-axis” position (or more precisely: having a magnetic center substantially located on the rotation axis of the magnet) and having eight horizontal Hall elements H0 to H7 and an IMC structure (referred to herein as a “sun structure”). The IMC structure has a central disk surrounded by eight radially oriented IMC elements having a generally trapezoidal shape. The sensor device has a semiconductor substrate oriented substantially perpendicular to the rotation axis. Such a sensor arrangement, although a “sun structure” with 12 Hall elements and 12 IMC elements is known in WO2014029885A1 (Figure 27), the sensor device described in WO'885 only provides a position signal, not an integrity signal or a fault signal.

[0130] Referring back to FIG1(a) of the present invention, it can be understood that a first signal indicating the angular position θ of the indicating magnet 102 relative to the sensor device 101 can be determined, for example, according to the following formula (or vice versa):

[0131] Signal 1 = arctan[(Vh1-Vh3+Vh5-Vh7) / (Vh0-Vh2+Vh4-Vh6)] [1a] where Vh0, Vh1, Vh2, etc. are signals (e.g., voltages) obtained from Hall elements H0, H1, H2, etc. This signal is highly insensitive to external disturbance fields in any direction. Then, the mechanical position θ can be derived from the first signal as follows:

[0132] Signal 1 = 2*θ [1b]

[0133] For example, a second signal indicating a fault or the system integrity at that location can be calculated using the following formula:

[0134] Signal 2 = (Vh1 - Vh3 + Vh5 - Vh7) 2 +(Vh0-Vh2+Vh4-Vh6) 2 [1c]

[0135] If the mechanical installation is correct, the signal is substantially constant and independent of angular position. This value can be predetermined, for example, during design, or it can be measured and stored in volatile memory, for example, during calibration testing. In the event of a mechanical installation problem, such as if the magnet is no longer present (e.g., accidentally removed due to vibration), the measured value of signal 2 will no longer be equal to the aforementioned constant value. Therefore, by measuring this value, a fault in the position sensor system can be detected, or in other words, the integrity of the position sensor system can be determined.

[0136] Note that (Vh1+Vh5) can be considered as the gradient signal (or spatial derivative) of the magnetic field component Bu oriented in the U direction along the U axis, and therefore can be written as dBu / du. Typically, the gradient is calculated as the difference (not the sum) between two parallel vectors pointing in the same direction, but in Figure 1(a), the gradient is calculated as a sum because the sensitivities of the Hall plates H1 and H5, and the associated IMC element, are opposite along the U axis.

[0137] Similarly, (Vh3+Vh7) is the gradient signal, which can also be written as dBv / dv.

[0138] Furthermore, (Vh0+Vh4) is the gradient signal, which can also be written as dBx / dx.

[0139] Furthermore, (Vh2+Vh6) is the gradient signal, which can also be written as dBy / dy.

[0140] Therefore, the second signal can also be written as:

[0141] Signal 2 = (dBu / du - dBv / dv) 2 +(dBx / dx-dBy / dy) 2 [1d]

[0142] Each of the X, Y, U, and V axes is parallel to the semiconductor substrate of the sensor device, and the U, Y, and V axes are located at 45°, 90°, and 135° relative to the X axis (measured in the counterclockwise direction), respectively.

[0143] As can be understood, in formulas [1a] and [1d], each term in the first and second squares has a coefficient of +1 or -1, but in practice, coefficients other than +1 or -1 may be used, for example, to account for sensitivity mismatch of sensor elements and / or gain mismatch of amplifiers (not shown). For example, suitable or optimal coefficients may be determined during calibration testing and stored in the non-volatile memory 1321 of the sensor device (see, for example, Figure 13 ).

[0144] Figure 1(b) shows a graph illustrating the magnitude of the difference between the two gradients dBx / dx and dBy / dy for various positions near the axis of rotation. From the figure, it can be understood that... Figure 1b In the example, the size is essentially constant within an imaginary circle with a radius of approximately 2 mm.

[0145] The second signal can also be identified as:

[0146] Signal 2 = (dBu / du) 2+(dBx / dx) 2 [1e]

[0147] The X-axis and U-axis are defined as an angle of 45°.

[0148] In the variant of the position sensor system shown in Figure 1, a hexapole or octapole magnet, or a magnet with more than eight poles, is used. In this case, the sensor structure must be adjusted so that the number of sensor elements is twice the number of poles.

[0149] exist Figure 12 The flowchart of method 1200 performed by a sensor device of the present invention (such as, for example, sensor device 101 of FIG. 1) will be shown, and... Figure 13 The diagram below shows a block diagram of such a sensor device.

[0150] Figure 2 An angular position sensor system 200 according to another embodiment of the invention is shown. The position sensor system 200 includes a quadrupole magnet 202 rotatable about a rotation axis (e.g., a radially or axially magnetized quadrupole ring magnet or quadrupole disk magnet), and a sensor device 201 located in an "on-axis" position (meaning having a magnetic center substantially located on the rotation axis). The sensor device 201 preferably includes a semiconductor substrate and is preferably oriented such that the substrate is substantially orthogonal to the rotation axis. The sensor device has four vertical Hall elements H0 to H3 located on a virtual circle, each configured to measure the radial magnetic field component of the magnetic field generated by the magnet 202. Figure 2 In the example, the vertical Hall elements are oriented such that the axis of their maximum sensitivity faces outward (as indicated by the arrow), but the invention will also work if the vertical Hall elements are oriented such that the axis of their maximum sensitivity faces inward, or even if these values ​​are correctly added or subtracted, such that some are oriented inward and others outward.

[0151] exist Figure 2 In the specific example shown, the angular position of the magnet can be calculated based on, for example, the following formula:

[0152] Signal 1 = arctan[(Vh0 + Vh1) / (Vh2 + Vh3)] [2a]

[0153] The mechanical position θ can be derived from the first signal, as follows: Signal 1 = 2 * θ. The first signal is insensitive to external disturbance fields. According to the invention, a second signal is determined, which indicates the fault or integrity of the sensor system, for example, electrical integrity and / or mechanical integrity. For example, this signal can be calculated according to the following formula:

[0154] Signal 2 = (Vh0 + Vh1)2 +(Vh2+Vh3) 2 [2b]

[0155] This can also be written as:

[0156] Signal 2 = (dBx / dx) 2 +(dBu / du) 2 [2c]

[0157] The X-axis and U-axis are defined as an angle of 45°.

[0158] exist Figure 2 In a variant of the illustrated embodiment (not shown), sensor device 201 has more than four vertical Hall elements (e.g., eight vertical Hall elements) located on an imaginary circle, these Hall elements being oriented radially inward or outward and spaced 45° apart. In this case, the second signal can be calculated as the sum of two terms, each term being the square of a linear combination of four signals, for example, a first-order polynomial with coefficients of +1 or -1, depending on the orientation (inward or outward) of the vertical Hall elements. As described above, one or more of the coefficients may be different from +1 or -1.

[0159] Figure 3 An angular position sensor system 300 according to another embodiment of the invention is shown. The position sensor system 300 includes a quadrupole magnet 302 rotatable about a rotation axis (e.g., a radially or axially magnetized quadrupole ring magnet or quadrupole disk magnet), and a sensor device 301 located in an "on-axis" position (meaning: having a magnetic center substantially located on the rotation axis). The sensor device 301 preferably includes a semiconductor substrate and is preferably oriented such that the substrate is substantially orthogonal to the rotation axis. The sensor device has four vertical Hall elements H0 to H3 located on a virtual circle and is configured to measure the circumferential magnetic field component (i.e., tangent to the virtual circle) of the magnetic field generated by the magnet 302. Figure 3 In the example, the vertical Hall elements H0 to H3 are oriented such that the axis of their maximum sensitivity points clockwise. However, if the vertical Hall elements are oriented such that the axis of their maximum sensitivity points counterclockwise, or even if these values ​​are correctly added or subtracted, such that some are oriented clockwise and others counterclockwise, the invention will also work.

[0160] exist Figure 3 In the specific example shown, the angular position of the magnet can be calculated based on, for example, the following formula:

[0161] Signal 1 = arctan[(Vh0 + Vh1) / (Vh2 + Vh3)] [3a]

[0162] The mechanical position θ can be derived from the first signal, as follows: Signal 1 = 2 * θ. The first signal is insensitive to external disturbance fields. According to the invention, a second signal is determined, which indicates a system fault or integrity, for example, electrical integrity and / or mechanical integrity. For example, this signal can be calculated according to the following formula:

[0163] Signal 2 = (Vh0 + Vh1) 2 +(Vh2+Vh3) 2 [3b]

[0164] This can also be written as:

[0165] Signal 2 = (dBy / dx) 2 +(dBv / du) 2 [3b]

[0166] The X, Y, U, and V axes are parallel to the substrate, and the U, Y, and V axes are defined at angles of 45°, 90°, and 135° respectively relative to the X axis in a counterclockwise direction.

[0167] exist Figure 3 In a variant of the illustrated embodiment (not shown), the sensor device has more than four vertical Hall elements (e.g., eight vertical Hall elements) located on an imaginary circle. These Hall elements are oriented such that the axis of their maximum sensitivity is tangent to the imaginary circle and points clockwise or counterclockwise, spaced 45 degrees apart. Similarly, in this case, the second signal can be calculated as the sum of two terms, each term being the square of a linear combination of four signals, for example, a first-order polynomial with coefficients of +1 or -1, depending on the orientation of the vertical Hall elements (inward or outward).

[0168] Figures 4(a) and 4(b) illustrate an angular position sensor system 400 according to another embodiment of the present invention. The position sensor system 400 includes a bipolar magnet (e.g., a bar magnet or a disk magnet or ring magnet that is diameterically or axially magnetized) rotatable about a rotation axis, and a sensor device 401 located in an "on-axis" position and having only three or four horizontal Hall elements but no IMC (Integrated Magnetic Concentrator). The sensor device 401 preferably includes a semiconductor substrate and is preferably oriented such that the substrate is substantially orthogonal to the rotation axis, thus the horizontal Hall elements are configured to measure a magnetic field component Bz that is substantially parallel to the rotation axis.

[0169] In the embodiment of FIG4(b), the sensor device 401 has four horizontal Hall elements H1 to H4 located on a circle and spaced 90° apart angularly.

[0170] The first signal indicating the angular position can be calculated as:

[0171] Signal 1=arctan[((Vh0-Vh2) / (Vh1-Vh3)] [4a]

[0172] The mechanical position θ can be derived from the first signal, as follows: Signal 1 = θ. The first signal is insensitive to external disturbance fields. According to the invention, a second signal is determined, which indicates a system fault or integrity, for example, the electrical integrity and / or mechanical integrity of the system. For example, this signal can be calculated according to the following formula:

[0173] Signal 2 = (Vh0 - Vh2) 2 +(Vh1-Vh3) 2 [4b]

[0174] This can also be written as:

[0175] Signal 2 = (dBz / dx) 2 +(dBz / dy) 2 [4c]

[0176] The X and Y axes are parallel to the substrate and are defined at a 90° angle, while the Z axis is perpendicular to the substrate.

[0177] In the embodiment shown in Figure 4(c), the sensor device 451 has only three horizontal Hall elements: one horizontal Hall element Hc is located at the center of the virtual circle, and two horizontal Hall elements H0 and H1 are located on the circle and spaced 90° apart. In this embodiment, the first signal indicating the mechanical position can be calculated according to the following formula:

[0178] Signal 1 = arctan[(Vh0 - Vhc) / (Vh1 - Vhc)] [4d]

[0179] Furthermore, a second signal indicating a system's fault or integrity (e.g., electrical integrity and / or mechanical integrity) can be calculated as:

[0180] Signal 2 = (Vh0 - Vhc) 2 +(Vh1-Vhc) 2 [4e]

[0181] This can also be written as:

[0182] Signal 2 = (dBz / dx) 2 +(dBz / dy) 2 [4f]

[0183] The X and Y axes are parallel to the substrate and are defined at a 90° angle, while the Z axis is perpendicular to the substrate.

[0184] Figure 4(d) shows the simulation results of the sum of the squares of the differences between each of the Hall elements H0, H1 on the circle and the central element Hc, for example, according to the formula:

[0185] Signal 2 = (Vh1 - Vhc) 2 +(Vh0-Vhc) 2

[0186] Among them, signal 2 is a signal indicating fault or system integrity, and Vh0 and Vh1 are signals obtained from two horizontal Hall elements H0 and H1 located on the virtual circle, and Vhc is a signal obtained from the horizontal Hall element Hc located at the center.

[0187] Since the horizontal Hall elements H0, H1, and Hc are oriented in the same (Z) direction, each of the difference signals (Vh1-Vhc) and (Vh0-Vhc) is essentially insensitive to external interference fields, and therefore the sum of the squares of these difference signals is also highly insensitive to external interference fields.

[0188] In the example shown, the sum is constant across the entire 360° measurement range. In practice, small variations in the signal may exist. It is possible to detect certain faults by calculating the sum and comparing it to a first threshold less than the constant, and / or by comparing it to a second threshold greater than the constant, and by testing whether the sum is a value below the first threshold and / or greater than the second threshold and / or between these two thresholds. In a practical implementation, the average or median can be determined during design and can be hard-coded, or the average or median can be determined during calibration testing and stored in the non-volatile memory 1321 of the sensor device 1320, which can be retrieved during actual use.

[0189] The first threshold can be a value ranging from 75% to 99% of the aforementioned average, for example, approximately 75%, approximately 80%, approximately 85%, approximately 90%, approximately 95%, approximately 96%, approximately 97%, or approximately 98%. The second threshold can be a value ranging from 101% to 125% of the aforementioned average, for example, approximately 102%, approximately 103%, approximately 104%, approximately 105%, approximately 110%, approximately 115%, approximately 120%, or approximately 125%.

[0190] As a numerical example, if a single signal has an amplitude of 1.0, the difference signal will also have an amplitude of approximately 1.0, and the average of the sum of squares will be equal to approximately 1.0. If the first threshold is set to 85% of 1.0 (approximately 0.85), and the second threshold is set to 115% of 1.0 (approximately 1.15), then if the calculated signal is a value within the range of 0.85 to 1.15, the second signal will indicate "system integrity is normal," while if the calculated sum is a value outside this range, the second signal will indicate "fault has occurred."

[0191] Figure 4(e) shows the simulation results of another second signal 2' indicating the fault, which is a variation of the formula in Figure 4(d), wherein the second signal 2' is calculated as the sum of the absolute values ​​of the differences between pairs of two magnetic field components, for example, according to the following formula:

[0192] Signal 2' = abs(Vh1 - Vhc) 2 +abs(Vh0-Vhc) 2

[0193] In this context, signal 2' is a signal indicating a fault or system integrity. Vh1 and Vh0 are signals provided by horizontal Hall elements located on the virtual circle, and Vhc is a signal provided by the horizontal Hall element located at the center, or a signal derived from them (e.g., after amplification, digitization, etc.). Since all horizontal Hall elements are oriented in the same direction (Z, perpendicular to the plane of the semiconductor substrate), each of the difference signals (Vh1-Vhc) and (Vh0-Vhc) is substantially insensitive to external interference fields, and therefore the sum of the absolute values ​​of these differences is also highly insensitive to external interference fields.

[0194] As a numerical example, if the original signals Vh1 and Vh0 have an amplitude of 1.0, then the difference signal will have an amplitude of approximately 1.0, and the sum of the absolute values ​​of these differences will be a value in the range of approximately 1.00 to approximately 1.41. Therefore, the average value is equal to approximately 1.20, and the "valid" sum of the absolute values ​​of the differences is a value in the range of approximately 1.00 to approximately 1.41, which is approximately 1.20 + / - approximately 18%.

[0195] In practice, considering typical tolerances (e.g., mechanical installation tolerances), a slightly larger tolerance margin can be chosen, such as ±20%, ±22%, ±24%, ±26%, ±28%, or ±30%. Of course, the larger this tolerance range, the lower the sensitivity of fault detection.

[0196] When comparing the examples in Figure 4(d) and Figure 4(e), it should be clear that the sum of squares in Figure 4(d) allows for a much smaller tolerance than the sum of absolute values ​​in Figure 4(e). However, the formula in Figure 4(d) requires calculating squares (and therefore multiplication), which is more demanding than calculating absolute values. Depending on the processor's capabilities (e.g., whether a hardware multiplier is present or not), a technician can choose either the second signal in Figure 4(d) or the second signal in Figure 4(e).

[0197] Figure 5 An angular position sensor system 500 according to another embodiment of the present invention is shown. The position sensor system 500 includes a bipolar magnet (e.g., a toroidal magnet or disk magnet magnetized radially) 502 rotatable about a rotation axis, and a sensor device 501 located in an “off-axis” position (e.g., “below the toroidal magnet” or “below the disk”) and configured to measure two circumferential field components (Bx) and two radial magnetic field components (By), as visible from the magnet.

[0198] Sensor device 501 preferably includes a semiconductor substrate, and is preferably oriented such that the substrate is substantially orthogonal to the axis of rotation. Figure 5 In the illustrated embodiment, the substrate of the sensor device is located at a predefined distance "g" (e.g., from 0.5 to 5.0 mm, for example, equal to about 2.0 mm) from the bottom or top surface of the annular magnet or disk magnet. The magnetic center of the sensor device is located at a distance "Rs" from the rotation axis (e.g., at least 1.4 mm, or at least 1.6 mm, or at least 1.8 mm, or at least 2.0 mm, or at least 2.5 mm, or at least 3.0 mm from the rotation axis). Figure 5 In the example, magnet 502 is a toroidal magnet with an inner radius Ri and an outer radius Ro, and Rs is preferably a value between the inner radius Ri and the outer radius Ro.

[0199] If an orthogonal coordinate system XYZ is connected to the sensor device such that the X-axis is tangent to the circumferential direction, the Z-axis is parallel to the rotation axis, and the Y-axis is radially oriented (i.e., perpendicular to the rotation axis), then the first signal indicating the angular position of the magnet relative to the sensor device (or vice versa) can be calculated as follows:

[0200] Signal 1 = arctan[K.(dBx / dx) / (dBy / dx)] [5a]

[0201] Where K is a constant, and K can be chosen such that the amplitude of K*(dBx / dx) is approximately equal to the amplitude of (dBy / dx).

[0202] Figure 5 (c) to Figure 5(d) shows various sensor structures that can be used to calculate these gradients. Figure 5 (c) The sensor device uses a so-called “dual-disc” structure comprising a horizontal Hall element and an IMC. More information about this structure can be found in US2018372475, the entire contents of which are incorporated herein by reference. Such disks can, for example, have a diameter of approximately 150 to approximately 250 micrometers, so the distance between two corresponding Hall elements can be on the order of approximately 200 micrometers. The distance between the centers of the two disks can be on the order of 1.5 mm to 2.5 mm, for example, equal to approximately 2.0 mm. Figure 5 The sensor device in (d) includes two pairs of vertical Hall elements spaced apart by a distance “dx” along the X-axis. Using the latter sensor structure, the value of dBx / dx can be calculated as (H2-H4), and the value of dBy / dx can be calculated as (H1-H3). However, other sensor structures can also be used. The second signal indicating the fault or integrity of the system in Figure 5 can be calculated as:

[0203] Signal 2 = A(dBx / dx) 2 +B(dBy / dx) 2 [5b]

[0204] Where A and B are constants. The values ​​of A and B can depend on the installation location (Rs and / or g). Preferably, the values ​​of A and B are chosen such that the second signal is substantially constant for all angular positions. In a preferred embodiment, the ratio of A / B is substantially equal to K. 2 In a particular embodiment, the value of B is chosen to be equal to 1, and the value of A is chosen to be equal to K. 2 .

[0205] Figure 6 An angular position sensor system 600 according to another embodiment of the present invention is shown, which can be considered as Figure 5 A variant of the 500 position sensor system.

[0206] Figure 6 The angular position sensor system 600 includes a bipolar magnet 602 rotatable about a rotation axis (e.g., a diameter-magnetized bipolar annular magnet or disk magnet), and a sensor device 601 located near a so-called "corner position" (e.g., near the periphery of the outer circle of the bottom or top surface of the annular magnet or disk magnet). The annular magnet or disk magnet has an outer radius Ro.

[0207] Sensor device 601 preferably includes a semiconductor substrate, and is preferably oriented such that the substrate is substantially orthogonal to the axis of rotation. Figure 6In the illustrated embodiment, the substrate of the sensor device is located in a plane at a predefined distance “g” (e.g., from 0.5 mm to 5.0 mm, for example, equal to about 2.0 mm) from the bottom or top surface of the annular magnet or disk magnet, and the substrate is substantially perpendicular to the rotation axis. The magnetic center of the sensor device 601 is located at a distance “Rs” from the rotation axis, which can be a value in the range of about 80% to 120% of Ro, or a value in the range of about 90% to 110% of Ro.

[0208] Figure 6 The sensor device 601 is configured to measure the circumferential field components (Bx1, Bx2) and axial field components (Bz1, Bz2) at two different positions X1 and X2 along the X-axis. If an orthogonal coordinate system XYZ is connected to the sensor device such that the X-axis is tangent to the circumferential direction, the Z-axis is perpendicular to the substrate and parallel to the rotation axis, and the Y-axis is parallel to the substrate and orthogonally intersects the rotation axis, then a first signal indicating the angular position of the magnet relative to the sensor device (or vice versa) can be calculated as follows:

[0209] Signal 1 = arctan[K*(dBx / dx) / (dBz / dx)] [6a]

[0210] Where K is a constant value, and K can be chosen such that the size of K*(dBx / dx) is approximately equal to the size of (dBz / dx).

[0211] Figure 6 (e) and Figure 6 (f) shows various sensor structures that can be used to calculate these gradients. Figure 6 (e) The sensor device uses a so-called “dual-disk” structure that includes a horizontal Hall element and an IMC. As mentioned above, more information about this structure can be found in US2018372475. Figure 6 The sensor device in (f) includes two horizontal Hall elements and two vertical Hall elements spaced apart by a distance "dx" along the X-axis. Using the latter sensor structure, the value of dBx / dx can be calculated as (Vh2 - Vh4), and the value of dBz / dx can be calculated as (Vh1 - Vh3). However, other sensor structures can also be used. (Indication) Figure 6 The second signal for a fault or integrity (e.g., electrical integrity and / or mechanical integrity) of a position sensor system can be calculated as:

[0212] Signal 2 = A(dBx / dx) 2 +B(dBz / dx) 2 [6b]

[0213] Where A and B are constants. The values ​​of A and B can depend on Rs and / or g. Preferably, the values ​​of A and B are chosen such that the second signal is substantially constant for all angular positions. In a preferred embodiment, the ratio of A / B is substantially equal to K. 2 In a particular embodiment, the value of B is chosen to be equal to 1, and the value of A is chosen to be equal to K. 2 The values ​​of A, B, and K can be predefined, for example, determined during the design phase and hard-coded, or they can be determined during calibration testing and stored in the non-volatile memory of the sensor device.

[0214] Figure 7 An angular position sensor system 700 according to another embodiment of the present invention is shown, which can be considered as Figure 6 A variant of the sensor system 600.

[0215] Figure 7 The angular position sensor system 700 includes a bipolar magnet 702 rotatable about a rotation axis (e.g., a diameter-magnetized bipolar annular magnet or disk magnet), and a sensor device 701 located near a so-called "corner position" (e.g., near the periphery of the outer circle of the bottom or top surface of the annular magnet or disk magnet). The annular magnet or disk magnet has an outer radius Ro.

[0216] The sensor device 801 preferably includes a semiconductor substrate, and is preferably oriented such that the substrate is substantially parallel to the axis of rotation. Figure 7 In the illustrated embodiment, the substrate of the sensor device is substantially located at a predefined distance “g” (e.g., from 0.5 to 5.0 mm, for example, equal to about 2.0 mm) from the bottom or top surface of the annular magnet or disk magnet. The magnetic center of the sensor device 701 is located at a distance “Rs” from the rotation axis, which can be a value in the range of about 80% to 120% of Ro, or a value in the range of about 90% to 110% of Ro.

[0217] Figure 7 The sensor device 701 is configured to measure the circumferential field components (Bx1, Bx2) and axial field components (Bz1, Bz2) at two different positions X1 and X2 along the X-axis. If an orthogonal coordinate system XYZ is connected to the sensor device such that the X-axis is tangent to the circumferential direction, the Y-axis is parallel to the substrate and parallel to the rotation axis, and the Z-axis is perpendicular to the substrate and orthogonally intersecting the rotation axis, then a first signal indicating the angular position of the magnet relative to the sensor device (or vice versa) can be calculated as follows:

[0218] Signal 1 = arctan[K*(dBx / dx) / (dBy / dx)] [7a]

[0219] Where K is a constant value, and K can be chosen such that the size of K*(dBx / dx) is approximately equal to the size of (dBy / dx).

[0220] Figure 7 (d) and Figure 7 (e) shows various sensor structures that can be used to calculate these gradients. Figure 7 (d) The sensor device uses a so-called "dual-disk" structure that includes a horizontal Hall element and an IMC. This can be compared with... Figure 6 (e) The same dual-disk structure, but the signals can be combined differently. As mentioned above, more information about this structure can be found in US2018372475. Figure 7 The sensor device in (e) comprises four vertical Hall elements H1 to H4, wherein the axes of maximum sensitivity of two (H2, H4) are oriented in the X-direction, and the axes of maximum sensitivity of two (H1, H3) are oriented in the Y-direction, spaced apart by a distance “dx” along the X-axis. Using the latter sensor structure, the value of dBx / dx can be calculated as (Vh2-Vh4), and the value of dBy / dx can be calculated as (Vh1-Vh3). However, other sensor structures may also be used. (Indication) Figure 7 The second signal for system failure or integrity can be calculated as:

[0221] Signal 2 = A(dBx / dx) 2 +B(dBy / dx) 2 [7b]

[0222] Where A and B are constants. The values ​​of A and B can depend on the installation location (e.g., depending on Rs and / or g). Preferably, the values ​​of A and B are chosen such that the second signal is substantially constant for all angular positions. In a preferred embodiment, the ratio of A / B is substantially equal to K. 2 In a particular embodiment, the value of B is chosen to be equal to 1, and the value of A is chosen to be equal to K. 2 The values ​​of A, B, and K can be predefined, for example, determined during the design phase and hard-coded, or they can be determined during calibration testing and stored in the non-volatile memory of the sensor device.

[0223] It should be pointed out that, Figure 7 The arrangement is also applicable to four-pole toroidal magnets or disk magnets, or magnets with more than four poles.

[0224] Figure 8An angular position sensor system 800 according to another embodiment of the present invention is shown. The angular position sensor system 800 includes a quadrupole magnet 802 (e.g., an axially magnetized toroidal magnet or an axially magnetized disk magnet) rotatable about a rotation axis, and a sensor device 801 located at a so-called "off-axis" position (e.g., at a distance of approximately 0.5 mm to 5.0 mm above or below the top or bottom surface of the magnet) and at a distance Rs from the rotation axis. If the magnet is a toroidal magnet having an inner radius Ri and an outer radius Ro, then Rs is preferably a value between Ri and Ro, for example, substantially between Ri and Ro.

[0225] Sensor device 801 is configured to measure two circumferential (Bx) magnetic field components and two axial (By) magnetic field components relative to a magnet. Figure 8 In the example, sensor device 801 has a substrate oriented substantially perpendicular to the axis of rotation, and the sensor device 801 is located at a distance “g” from the bottom surface of magnet 802.

[0226] If an orthogonal coordinate system X, Y, Z is attached to a sensor device such that the X and Y axes are parallel to the substrate, the Z axis is perpendicular to the substrate, the X axis is tangent to an imaginary circle of radius "Rs", the Z axis is parallel to the rotation axis, and the Y axis is radially oriented, then the first signal indicating the angular position can be written as:

[0227] Signal 1 = arctan[K*(dBx / dx) / (dBz / dx)] [8a]

[0228] Where K is a constant value, and K can be chosen such that the magnitude of K multiplied by the gradient (dBx / dx) is approximately equal to the magnitude of the gradient (dBz / dx).

[0229] The second signal indicating a fault or integrity of the position sensor system 800 can be calculated as:

[0230] Signal 2 = A(dBx / dx) 2 +B(dBz / dx) 2 [8b]

[0231] Where A and B are constants. The values ​​of A and B can depend on the installation location (e.g., depending on Rs and / or g). Preferably, the values ​​of A and B are chosen such that the second signal is substantially constant for all angular positions. In a preferred embodiment, the ratio of A / B is substantially equal to K. 2 In a particular embodiment, the value of B is chosen to be equal to 1, and the value of A is chosen to be equal to K. 2The values ​​of A, B, and K can be predefined (e.g., determined during design and, for example, hard-coded), or they can be determined during calibration testing and stored in the non-volatile memory of the sensor device.

[0232] Figure 8 (c) and Figure 8 (d) shows some examples of sensor structures that can be used to measure the magnetic field components and determine the gradient, but the invention is not limited thereto and other suitable sensor structures can also be used. Figure 8 c illustrates a “dual-disk structure” with four horizontal Hall elements and two IMC disks. As mentioned above, the disks can have a diameter of approximately 200 micrometers and can be spaced approximately 2.0 mm apart. Figure 8 (d) shows a sensor structure with two horizontal Hall elements and two vertical Hall elements, with a predefined distance “dx” between the two horizontal Hall elements and between the two vertical Hall elements, for example, in the range of about 1.0 mm to about 3.0 mm, but other suitable distances may also be used.

[0233] In one variant, magnet 802 may include more than four poles, for example, six or eight poles, or more than eight poles.

[0234] Figure 9 An angular position sensor system 900 according to another embodiment of the present invention is shown. The position sensor system 900 includes a multipole magnet 902 rotatable about a rotation axis (e.g., a ring magnet with radial magnetization having at least four, at least six, or at least eight poles or more than eight pole pairs) and a sensor device 901.

[0235] Sensor device 901 is located at a distance “Rs” from the rotation axis, where Rs is greater than the outer radius Ro of the magnet. Sensor device 901 is configured to measure the circumferential magnetic field component Bx (tangent to an imaginary circle of radius Rs) and the radial magnetic field component By (relative to the magnet) at two positions X1 and X2 spaced apart along the X-axis. It has a substrate oriented substantially perpendicular to the rotation axis and is located in a plane β perpendicular to the rotation axis, substantially midway between the top and bottom planes of the magnet. If the magnet has a thickness T, the substrate is preferably located at a distance T / 2 from the bottom and top planes.

[0236] If an orthogonal coordinate system X, Y, Z is attached to a sensor device such that the X and Y axes are parallel to the substrate, the Z axis is perpendicular to the substrate, the X axis is tangent to an imaginary circle of radius "Rs", the Z axis is parallel to the rotation axis, and the Y axis is radially oriented, then the first signal indicating the angular position can be written as:

[0237] Signal 1 = arctan[K*(dBx / dx) / (dBy / dx)] [9a]

[0238] Where K is a constant value, and K can be chosen such that the magnitude of K multiplied by the gradient (dBx / dx) is approximately equal to the magnitude of the gradient (dBy / dx).

[0239] Furthermore, a second signal indicating a fault or integrity (e.g., electrical integrity and / or mechanical integrity) of the position sensor system can be calculated as:

[0240] Signal 2 = A(dBx / dx) 2 +B(dBy / dx) 2 [9b]

[0241] Where A and B are constants. The values ​​of A and B can depend on Rs and / or h. Preferably, the values ​​of A and B are chosen such that the second signal is substantially constant for all angular positions. In a preferred embodiment, the ratio of A / B is substantially equal to K. 2 In a particular embodiment, the value of B is chosen to be equal to 1, and the value of A is chosen to be equal to K. 2 The values ​​of A, B, and K can be predefined, for example, determined during the design phase and hard-coded, or they can be determined during calibration testing and stored in the non-volatile memory of the sensor device.

[0242] Figure 9 (c) and Figure 9 (d) shows some examples of sensor structures that can be used to measure the magnetic field components and determine the gradient, but the invention is not limited thereto and other suitable sensor structures can also be used. Figure 9 (c) shows a “dual-disk structure” with eight horizontal Hall elements and two IMC disks. Figure 9 (d) shows a sensor structure with four vertical Hall elements. However, other suitable sensor structures can also be used.

[0243] In variants, magnet 902 may include fewer than eight pole pairs, such as four or six pole pairs, or more than eight pole pairs (e.g., 10 or 12 pole pairs).

[0244] Figure 10 An angular position sensor system 1000 according to another embodiment of the present invention is shown, which can be considered as Figure 9 The variants differ mainly in the following ways:

[0245] -The substrate of the sensor device 1001 is parallel to the rotation axis of the magnet.

[0246] - The Z-axis (perpendicular to the substrate) is oriented radially relative to the magnet, and the Y-axis is parallel to the rotation axis.

[0247] The sensor structure of the sensor device 1001 is configured to measure the gradient of the circumferential field component (tangent to an imaginary circle of radius Rs) and the gradient of the radial field component relative to the rotation axis, but these gradients are calculated by the sensor device in a different manner.

[0248] Figure 10 (a) shows the front view. Figure 10 (b) shows a top view. Figure 10 (c) shows a side view.

[0249] Figure 10 (d) shows that the sensor device may include a “dual-disc” structure.

[0250] Figure 10 (e) illustrates that the sensor device may include two vertical Hall elements and two horizontal Hall elements, spaced apart in the X direction, which is tangent to an imaginary circle of radius "Rs". The radius Rs is greater than the outer radius Ro.

[0251] If an orthogonal coordinate system X, Y, Z is attached to the sensor device such that the X and Y axes are parallel to the substrate, the Z axis is perpendicular to the substrate, the X axis is tangent to an imaginary circle of radius "Rs", the Y axis is parallel to the rotation axis, and the Z axis is perpendicular to the rotation axis, then the first signal indicating the angular position can be written as:

[0252] Signal 1 = arctan[K*(dBx / dx) / (dBz / dx)] [10a]

[0253] Where K is a constant value, and K can be chosen such that the magnitude of K multiplied by the gradient (dBx / dx) is approximately equal to the magnitude of the gradient (dBz / dx).

[0254] Furthermore, a second signal indicating a fault or integrity (e.g., electrical integrity and / or mechanical integrity) of the position sensor system can be calculated as:

[0255] Signal 2 = A(dBx / dx) 2 +B(dBz / dx) 2 [10b]

[0256] Where A and B are constants. The values ​​of A and B can depend on Rs and / or h. Preferably, the values ​​of A and B are chosen such that the second signal is substantially constant for all angular positions. In a preferred embodiment, the ratio of A / B is substantially equal to K. 2In a particular embodiment, the value of B is chosen to be equal to 1, and the value of A is chosen to be equal to K. 2 The values ​​of A, B, and K can be predefined (e.g., determined during design and, for example, hard-coded), or they can be determined during calibration testing and stored in the non-volatile memory of the sensor device.

[0257] Figure 10 (d) and Figure 10 (e) shows some examples of sensor structures that can be used to measure the magnetic field components and determine the gradient, but the invention is not limited thereto and other suitable sensor structures can also be used. Figure 10 (d) shows a “dual-disk structure” with eight horizontal Hall elements and two IMC disks. Figure 10 (e) illustrates a sensor structure with two vertical Hall elements and two horizontal Hall elements. However, other suitable sensor structures may also be used. Readers can find more details about the “dual-disk structure” and how it can be used to determine magnetic field gradients in US2018372475A1, the entire contents of which are incorporated herein by reference.

[0258] Figure 11 A linear position sensor system 1100 according to another embodiment of the present invention is shown. The position sensor system 1100 includes a multipole magnetic structure 1102 and a sensor device 1101. The multipole magnetic structure 1102 has an elongated shape extending in a first direction X and has a plurality of magnetic poles magnetized in a second direction Z substantially perpendicular to the first direction X. The sensor device 1101 is configured to measure two magnetic field components Bx oriented in the first direction X and two magnetic field components Bz oriented in the second direction Z at two different positions X1 and X2 spaced apart in the first direction X, and to calculate a first gradient dBx / dx and a second gradient dBz / dx based on these field components.

[0259] If an orthogonal coordinate system X, Y, Z is connected to a sensor device, such as Figure 11 As shown, the first signal indicating the angular position can be calculated using the following formula:

[0260] Signal 1 = arctan[K*(dBx / dx) / (dBz / dx)] [11a]

[0261] Where K is a constant value, which can be chosen such that the magnitude of K multiplied by the gradient (dBx / dx) is substantially equal to the magnitude of the gradient (dBz / dx). This angular position can be converted to a linear position in a known manner (e.g., by multiplying the angular position by a constant (e.g., corresponding to 2*p / 360°) and by considering the extrema from the starting position, or in any other way).

[0262] Furthermore, the second signal indicating the fault or integrity (e.g., electrical integrity and / or mechanical integrity) of the linear position sensor system 1100 can be calculated according to the following formula:

[0263] Signal 2 = A(dBx / dx) 2 +B(dBz / dx) 2 [11b]

[0264] Figure 11 (b) and Figure 11 (c) shows several sensor structures that can be used to calculate the gradient. Figure 11 (b) The sensor structure includes a so-called “dual-disk structure” with four horizontal Hall plates and two IMC disks (where, simply put, the Bx component can be determined by subtracting the signals obtained from two corresponding Hall elements located on opposite sides of the same disk, and the Bz component can be determined by adding the signals obtained from these two Hall elements). Figure 11 (c) The sensor structure includes two horizontal Hall plates H1 and H3 configured to measure Bz at X1 and X2 spaced along the X-axis, and two vertical Hall plates H2 and H4 configured to measure Bx at X1 and X2.

[0265] In a preferred embodiment, dx is less than p / 4 or less than p / 6, or less than p / 8 or less than p / 10, or less than p / 12, where p is the distance between the centers of adjacent poles. However, the invention is not limited to this, and other values ​​of dx relative to p can also be used.

[0266] Figure 12 A flowchart of method 1200 is shown to determine a first signal (or first value) indicating position and a second signal (or second value) indicating fault or integrity (e.g., electrical integrity and / or mechanical integrity) of a position sensor system. The system includes a magnetic source and a sensor device movably mounted (or vice versa) relative to the magnetic source, wherein both the first and second signals are insensitive to external interference fields. Method 1200 includes the following steps:

[0267] a) Measure at least three magnetic field values ​​of the magnetic field generated by the magnetic source 1201 (e.g., Vh0, Vhc, Vh1 in Figure 4(c); or Figures 5 to 10 (Vh1 to Vh4 in the middle);

[0268] b) Based on the at least three magnetic field values, determine at least two magnetic field gradients for 1202 (e.g., Figure 1, Figure 2 dBu / du and dBx / dx in Figure 4; or dBz / dx and dBz / dy in Figure 4; or Figure 5 , Figure 7 , Figure 9 dBx / dx and dBy / dx; or Figure 6 , Figure 8 , Figure 10 (dBx / dx and dBz / dx) or at least two or more magnetic field differences (see, for example, Figure 14 (a) to Figure 16 (d));

[0269] c) Derive from the at least two magnetic field gradients or from the at least two or at least three magnetic field differences a first signal or first value “Signal 1” indicating the (e.g., linear or angular) position of the sensor device;

[0270] d) A second signal “signal 2” is derived from the at least two magnetic field gradients or from the at least two or at least three magnetic field differences to indicate a fault or integrity (e.g., electrical integrity and / or mechanical integrity) of the position sensor system, for example, indicating the presence of the magnetic source.

[0271] Step a) may include: measuring three magnetic field values ​​oriented in a single direction at three different locations, or measuring two magnetic field values ​​at a first location and two magnetic field values ​​at a second location different from the first location.

[0272] Step b) may include, for example, in the case of an angular position sensor system, measuring the spatial gradient along the direction of relative motion, in the circumferential direction, or in a direction tangent to an imaginary circle having its center located on the axis of rotation.

[0273] In an embodiment, step b) may include, for example, as Figure 14 (c) or Figure 14 As shown in the example in (d), the difference between signals obtained from individual horizontal Hall elements located on a virtual circle is determined.

[0274] In an embodiment, step b) may include, for example, as Figure 15 (c) or Figure 15 As shown in the example in (d), the difference between the signal obtained from the horizontal Hall element located on the virtual circle and the signal obtained from the vertical Hall element located at the center of the circle is determined.

[0275] In an embodiment, step b) may include, for example, as Figure 16 (c) or Figure 16 As shown in the example in (d), the average signal of the signal obtained from the horizontal Hall element located on the circle is calculated, and the difference between the signal obtained from the horizontal Hall element located on the virtual circle and the average signal is calculated.

[0276] Step c) may further include: converting the first signal into an angular position, for example, according to the following formula: Signal 1 = N * θ, where N is an integer and θ is a mechanical angle. For a bipolar magnet, the value of N is typically equal to 1, while for a quadrupole magnet, the value of N is typically equal to 2.

[0277] In the case of a linear position sensor, step c) may further include converting the angular position value into a linear position value, for example by taking into account the pole number of the sensor device.

[0278] The method may optionally further include step e):

[0279] e) The second signal is compared with at least one threshold 1205, and the comparison result is output, for example, in the form of a low or high voltage level, corresponding to "good" or "bad" system integrity. It is also possible to compare the second signal with more than one threshold (e.g., with a lower threshold and a higher threshold), and output the comparison result in the form of a "good signal," "warning signal," or "error signal." Other variations will be readily apparent to those skilled in the art upon which this disclosure is made.

[0280] Figure 13 This is a schematic block diagram of an exemplary position sensor device 1302 that may be used in embodiments of the present invention. Position sensor devices are known in the art, but a brief description is provided for completeness.

[0281] Figure 13 Position sensor device 1302 includes components arranged in a specific manner as described above (e.g., in Figures 1 to 1). Figure 11 Multiple magnetically sensitive elements (e.g., eight horizontal Hall elements H0 to H7 in the example of Figure 1) on a semiconductor substrate (in the middle) Figure 2 The example shows four vertical Hall elements; etc.

[0282] The position sensor device 1302 further includes a processor or processing circuit, such as a programmable processing unit 1320, which is adapted to determine a first gradient signal and a second gradient signal based on signals acquired from the magnetic sensor element (e.g., by summing or subtracting two or more values).

[0283] The processing unit 1320 is preferably further adapted to determine a position, for example, an angular position based on the ratio of these gradient signals, for example, using a lookup table and interpolation, or by using an angle measurement function (e.g., an arctangent function) or any other suitable method. In the case of a linear position sensor system, the processing unit 1320 may be further adapted to convert the angular position value into a linear position value.

[0284] This position value can be output by the controller as the first output signal "POS".

[0285] According to the basic principles of the invention, the controller also calculates and optionally outputs a second signal "signal 2" or a value derived therefrom that indicates a fault or integrity of the system, for example after comparing the second signal with one or more predefined thresholds.

[0286] In an embodiment, the controller 1320 is configured to test whether the second signal is within a first predetermined range, and if the test result is true, the controller outputs an integrity signal "INT" with a first level (e.g., logic "1") corresponding to a "good" condition, and if the test result is false, the controller outputs a second level (e.g., logic "0") integrity signal corresponding to a "bad" condition, or vice versa. The output signal may be provided as a digital signal, an analog signal, or a combination thereof.

[0287] Although not explicitly shown, sensor device 1320 typically further includes bias circuitry, readout circuitry, one or more amplifiers, analog-to-digital converters (ADCs), etc. Such circuitry is well known in the art but is not the primary focus of this invention.

[0288] Although the present invention is described primarily using horizontal Hall elements and / or vertical Hall elements, the present invention is not limited to this type of magnetic sensing element, and other types of magnetic sensing elements, such as circular Hall elements or magnetoresistive elements, such as XMR or GMR elements, may also be used.

[0289] Figure 14 (a) and Figure 14 (b) illustrates another embodiment of the sensor system 1400, including a bipolar magnet 1402 and a sensor device 1401 comprising three horizontal Hall elements H1, H2, and H3 located on a virtual circle and angularly spaced in multiples of 120°. The magnet 1402 may be an axially or radially magnetized ring or disk magnet. The center of the virtual circle is preferably located on the rotation axis of the magnet. Each of the horizontal Hall elements H1, H2, and H3 measures a magnetic field component Bz oriented in the Z direction and perpendicular to the semiconductor substrate. The values ​​provided by the Hall elements H1, H2, and H3 are Vh1, Vh2, and Vh3, respectively.

[0290] Figure 14 (a) is a schematic diagram of sensor device 1401.

[0291] Figure 14 (b) is a perspective view of sensor system 1400.

[0292] Figure 14(c) shows the simulation results of the sum of squares of the differences between pairs of two magnetic field components, for example, according to the following formula:

[0293] Signal 2 = (Vh1 - Vh2) 2 +(Vh2-Vh3) 2 +(Vh3-Vh1) 2

[0294] Signal 2 is a fault indication signal, and Vh1, Vh2, and Vh3 are signals provided by (or derived from, for example, amplified, digitized, etc.) the horizontal Hall elements. Since the horizontal Hall elements H1, H2, and H3 are oriented in the same (Z) direction, each of the difference signals (Vh1-Vh2), (Vh2-Vh3), and (Vh3-Vh1) is essentially insensitive to external interference fields, and therefore the sum of the squares of these difference signals is highly insensitive to external interference fields.

[0295] In the example shown, the sum of the squares is constant across the entire 360° measurement range. In practice, the signal may vary slightly (e.g., due to differences in the magnetic sensitivity of the sensor elements). It is possible to detect certain faults by calculating the sum and comparing it to a first threshold less than the constant, and / or by comparing it to a second threshold greater than the constant, and by testing whether the sum is a value less than a lower threshold and / or greater than an upper threshold and / or a value between these two thresholds. In a practical implementation, the average or median value can be determined during design and can be hard-coded, or the average or median value can be determined during calibration testing and stored in the sensor device's non-volatile memory, which can be retrieved during actual use.

[0296] The first threshold can be a value ranging from 75% to 99% of the aforementioned average, for example, approximately 75%, approximately 80%, approximately 85%, approximately 90%, approximately 95%, approximately 96%, approximately 97%, or approximately 98%. The second threshold can be a value ranging from 101% to 125% of the aforementioned average, for example, approximately 102%, approximately 103%, approximately 104%, approximately 105%, approximately 110%, approximately 115%, approximately 120%, or approximately 125%.

[0297] As a numerical example, if a single signal has an amplitude of 1.0, the difference signal will also have an amplitude of approximately 1.73, and the average will be approximately 4.5. If the first threshold is set to 85% of 4.5 (approximately 3.83), and the second threshold is set to 115% of 4.5 (approximately 5.18), then if the calculated signal is a value within the range of 3.83 to 5.18, the second signal will indicate "system integrity is normal," while if the calculated sum is a value outside this range, the second signal will indicate "fault has occurred."

[0298] Figure 14 (d) shows the simulation results of another second signal 2' indicating a fault, which is Figure 14 (c) A variant of the formula, wherein the second signal 2' is calculated as the sum of the absolute values ​​of the differences between pairs of two magnetic field components, for example, according to the following formula:

[0299] Signal 2' = abs(Vh1 - Vh2) 2 +abs(Vh2-Vh3) 2 +abs(Vh3-Vh1) 2

[0300] Here, signal 2' is a fault indication signal, and Vh1, Vh2, and Vh3 are signals provided by horizontal Hall elements H1 to H3 (or signals derived from them, for example, after amplification, digitization, etc.). Since the horizontal Hall elements are oriented in the same (Z) direction, each of the difference signals (Vh1-Vh2), (Vh2-Vh3), and (Vh3-Vh1) is essentially insensitive to external disturbance fields, and therefore the sum of the absolute values ​​of these differences is highly insensitive to external disturbance fields.

[0301] As a numerical example, if the original signals Vh1, Vh2, and Vh3 have an amplitude of 1.0, then the difference signal will have an amplitude of approximately 1.73, and the sum of the absolute values ​​of these differences will be a value in the range of approximately 3.00 to approximately 3.46. Therefore, the average value is equal to approximately 3.23, and the "valid" sum of the absolute values ​​of the differences is a value in the range of approximately 3.00 to approximately 3.46, which is approximately 3.23 + / - approximately 7%.

[0302] Surprisingly, the sum of the absolute values ​​of these differences has a small “ripple” (only about + / - 7%), especially considering simple arithmetic: taking the absolute value is a very simple operation (simply omitting the sign), unlike, for example, calculating squares or polynomials, which typically require hardware multipliers and usually take much longer to process.

[0303] In practice, considering typical tolerances (e.g., mechanical installation tolerances), a slightly larger tolerance margin can be chosen, such as ±10%, ±12%, ±14%, ±16%, ±18%, or ±20%. Of course, the larger this tolerance range, the lower the sensitivity of fault detection.

[0304] Figure 15 (a) and Figure 15 (b) illustrates another embodiment of a sensor system 1500, which includes a bipolar magnet and a sensor device 1501. The sensor device 1501 includes three horizontal Hall elements H1, H2, H3 located on a circle and angularly spaced in multiples of 120°, and a fourth horizontal Hall element Hc located at the center of the circle. The magnet 2 can be an annular or disk magnet magnetized axially or radially. The center of the virtual circle is preferably located on the rotation axis of the magnet. Each of the horizontal Hall elements H1, H2, H3, Hc measures a magnetic field component Bz oriented in the Z direction and perpendicular to the semiconductor substrate. The values ​​provided by the Hall elements H1, H2, H3, Hc are Vh1, Vh2 and Vh3, Vhc, respectively.

[0305] Figure 15 (a) is a schematic diagram of sensor device 1501.

[0306] Figure 15 (b) is a perspective view of sensor system 1500.

[0307] Figure 15 (c) shows the simulation results of the sum of the squares of the differences between each of the Hall elements H1, H2, H3 on the circle and the central Hall element Hc, for example, according to the following formula:

[0308] Signal 2 = (Vh1 - Vhc) 2 +(Vh2-Vhc) 2 +(Vh3-Vhc) 2

[0309] Signal 2 is a fault indication signal. Vh1, Vh2, Vh3, and Vhc are signals provided by (or derived from, for example, amplified, digitized, etc.) the horizontal Hall elements H1, H2, H3, and Hc. Since the horizontal Hall elements are oriented in the same (Z) direction, each of the difference signals (Vh1-Vhc), (Vh2-Vhc), and (Vh3-Vhc) is essentially insensitive to external interference fields, and therefore the sum of the squares of these difference signals is highly insensitive to external interference fields.

[0310] In the example shown, the sum is constant across the entire 360° measurement range. In practice, the signal may vary slightly (e.g., due to differences in the magnetic sensitivity of the sensor elements). Certain faults can be detected by calculating the sum and comparing it to a first threshold less than the constant, and / or by comparing it to a second threshold greater than the constant, and by testing whether the sum falls between these two thresholds. In practical implementations, the average or median value can be determined during design and can be hard-coded, or the average or median value can be determined during calibration testing and stored in the sensor device's non-volatile memory, which can be retrieved during actual use.

[0311] The first threshold can be a value ranging from 75% to 99% of the aforementioned average, for example, approximately 75%, approximately 80%, approximately 85%, approximately 90%, approximately 95%, approximately 96%, approximately 97%, or approximately 98%. The second threshold can be a value ranging from 101% to 125% of the aforementioned average, for example, approximately 102%, approximately 103%, approximately 104%, approximately 105%, approximately 110%, approximately 115%, approximately 120%, or approximately 125%.

[0312] As a numerical example, if individual signals Vh1, Vh2, and Vh3 have an amplitude of 1.0, the difference signal will also have an amplitude of approximately 1.0, and the average value will be approximately 1.5. If the first threshold is set to 85% of 1.5 (approximately 1.28), and the second threshold is set to 115% of 1.5 (approximately 1.73), then if the calculated signal is a value within the range of 1.28 to 1.73, the second signal will indicate "system integrity is normal," while if the calculated sum is a value outside this range, the second signal will indicate "fault detected."

[0313] Figure 15 (d) shows the simulation results of another second signal 2' indicating a fault, which is Figure 15 (c) A variant of the formula, wherein the second signal 2' is calculated as the sum of the absolute values ​​of the differences between each of the Hall elements H1, H2, H3 located on the circle and the central element Hc, for example, according to the following formula:

[0314] Signal 2' = abs(Vh1 - Vhc) 2 +abs(Vh2-Vhc) 2 +abs(Vh3-Vhc) 2

[0315] In this context, signal 2' is a fault indication signal, Vh1, Vh2, and Vh3 are signals provided (or derived from, for example, amplified, digitized, etc.) by horizontal Hall elements H1, H2, and H3 located on the circle, and Vhc is a signal provided (or derived from) the central Hall element Hc. Since the horizontal Hall elements are oriented in the same (Z) direction, each of the difference signals (Vh1-Vhc), (Vh2-Vhc), and (Vh3-Vhc) is substantially insensitive to external interference fields, and therefore the sum of the absolute values ​​of these differences is highly insensitive to external interference fields.

[0316] As a numerical example, if the original signals Vh1, Vh2, and Vh3 have an amplitude of 1.0, then the difference signal will have an amplitude of approximately 1.0, and the sum of the absolute values ​​of these differences will be a value in the range of approximately 1.73 to approximately 2.00. Therefore, the average value is equal to approximately 1.87, and the "valid" sum of the absolute values ​​of the differences is a value in the range of approximately 1.73 to approximately 2.00, which is approximately 1.87 + / - approximately 7%.

[0317] Surprisingly, the sum of the absolute values ​​of these differences has a small “ripple” (only about + / - 7%), especially considering simple arithmetic: taking the absolute value is a very simple operation (simply omitting the sign), unlike, for example, calculating squares or polynomials, which typically require hardware multipliers and usually take much longer to process.

[0318] In practice, considering typical tolerances (e.g., mechanical installation tolerances), a slightly larger tolerance margin can be chosen, such as ±10%, ±12%, ±14%, ±16%, ±18%, or ±20%. Of course, the larger this tolerance range, the lower the sensitivity of fault detection.

[0319] Figure 16 (a) and Figure 16 (b) illustrates another embodiment of the sensor system 1600, including a bipolar magnet and a sensor device 1601 comprising three horizontal Hall elements H1, H2, H3 located on a circle and spaced angularly at multiples of 120°. The sensor device 1601 is configured to determine (e.g., in hardware and / or software) the average signal Vavg according to the following formula:

[0320] Vavg = (Vh1 + Vh2 + Vh3) / 3

[0321] Among them, Vh1, Vh2, and Vh3 are signals provided by horizontal Hall elements H1, H2, and H3, and Vavg is the average value of these three signals.

[0322] Figure 16(c) shows the simulation results of the sum of the squares of the differences between each magnetic field component and the average signal; this simulation provides a comparison with... Figure 15 The same result is shown in (c), and all of the above applies here as well.

[0323] Figure 16 (d) shows the simulation results of the sum of the absolute values ​​of the differences between each magnetic field component and the average signal. This simulation provides a comparison with... Figure 15 The same result is shown in (d), and all of the above applies here as well.

[0324] Although Figure 14 (a)-(d) Figure 15 (a)-(d) and Figure 16 The embodiments (a)-(d) are shown for a sensor system comprising a bipolar magnet and a sensor device including three horizontal Hall elements arranged on a circle and optionally a central Hall element. The same principle applies to a sensor system (not shown) comprising a quadrupole magnet (e.g., a quadrupole toroidal or disk magnet) and a sensor device (not shown) including six horizontal Hall elements arranged on a circle and spaced at angular intervals of multiples of 60° and optionally a central element Hc. The second signal can be calculated as: Signal 2 = (Vh1 - Vh2) 2 +(Vh2-Vh3) 2 +(Vh3-Vh4) 2 +(Vh4-Vh5) 2 +(Vh5- Vh6) 2 +(Vh6-Vh1) 2 The first signal is calculated as the sum of the squares of the differences between the signals obtained from adjacent Hall elements. It can be seen that the sum of these signals is essentially constant. The second signal can also be calculated as: Signal 2' = abs(Vh1-Vh2) + abs(Vh2-Vh3) + abs(Vh3-Vh4) + abs(Vh4-Vh5) + abs(Vh5-Vh6) + abs(Vh6-Vh1), where the sum of the absolute values ​​of the differences between the signals obtained from adjacent Hall elements is calculated. It can be seen that the sum of these signals has relatively small ripple.

[0325] Although the above only refers to Figure 4(c), Figure 14 (b) Figure 15 (b) and Figure 16The system shown in (b) explicitly describes a second signal in the form of the sum of absolute values, but it will be clear to skilled readers who benefit from this disclosure that in the other systems described above, a second signal in the form of the sum of the squares of the gradients or differences can be used, or a second signal in the form of the sum of the absolute values ​​of the gradients or differences can be used, or a second signal in the form of another function that is substantially constant over the measurement range, such as, for example, at least a second-order polynomial function, for example, a polynomial that includes only second- and fourth-order terms, or a polynomial that includes only even-order terms, but the invention is not limited thereto.

Claims

1. A position sensor system, comprising: A magnetic field source, which is used to generate a magnetic field; A position sensor device, wherein the position sensor device is movable relative to the magnetic field source, or the magnetic field source is movable relative to the position sensor device. The position sensor device includes: Semiconductor substrate; At least three magnetic sensing elements, said at least three magnetic sensing elements for measuring at least three magnetic field values ​​of the magnetic field, wherein said at least three magnetic sensing elements include a Hall element integrated in the semiconductor substrate; and The processing circuit is configured to acquire the at least three magnetic field values, and to determine at least two magnetic field gradients or at least two magnetic field differences based on the at least three magnetic field values, and to derive a first signal from the at least two magnetic field gradients or from the at least two magnetic field differences indicating the position of the magnetic field source relative to the position sensor device. Its features are, The processing circuitry is further configured to derive a second signal indicating a fault or integrity of the position sensor system from the at least two magnetic field gradients or from the at least two magnetic field differences. The magnetic field source is a magnetic structure having an elongated shape extending in a first direction (X) and having at least two, at least three, or at least four magnetic poles magnetized in a second direction (Z) substantially perpendicular to the first direction (X). The position sensor device is movable relative to the magnetic structure in the first direction (X), or the magnetic structure is movable relative to the position sensor device in the first direction (X), and the position sensor device is configured to determine a linear position in the first direction (X). The distance between the position sensor device and the magnetic structure is substantially constant. The sensor device is configured to measure a first magnetic field component (Bx) oriented in the first direction (X) and a second magnetic field component (Bz) oriented in the second direction (Z). The position sensor device is configured to determine a first magnetic field gradient (dBx / dx) of the first magnetic field component (Bx) along the first direction (X), and to determine a second magnetic field gradient (dBz / dx) of the second magnetic field component (Bz) along the first direction (X). Furthermore, the position sensor device is configured to calculate the second signal as a function of the first magnetic field gradient and the second magnetic field gradient; Alternatively, the position sensor device is configured to determine a first magnetic field difference of the first magnetic field component (Bx) and a second magnetic field difference of the second magnetic field component (Bz); Furthermore, the position sensor device is configured to calculate the second signal as a function of the first magnetic field difference and the second magnetic field difference.

2. The position sensor system according to claim 1, Its features are, The position sensor device includes at least three magnetic sensor elements oriented in a single direction.

3. The position sensor system according to claim 1, Its features are, The second signal is selected such that it is substantially independent of its relative position within the measurement range.

4. The position sensor system according to claim 1, Its features are, The position sensor device is further configured to determine the second signal as a polynomial expression of the at least two magnetic field gradients or a polynomial expression of the at least two magnetic field differences, the polynomial expression having at least two orders.

5. The position sensor system according to claim 1, Its features are, The position sensor device is further configured to determine the second signal as the sum of the squares of the at least two magnetic field gradients, or as the sum of the squares of the at least two magnetic field differences.

6. The position sensor system according to claim 1, Its features are, The position sensor device is further configured to determine the second signal as the sum of the absolute values ​​of the at least two magnetic field gradients, or as the sum of the absolute values ​​of the at least two magnetic field differences.

7. The position sensor system according to claim 1, Its features are, The position sensor device is further configured to compare the second signal with at least one threshold (T1) and to provide an output signal corresponding to the result of the at least one comparison.

8. A method (1200) for determining the position of a position sensor system according to claim 1 and for determining a fault or integrity of the position sensor system, the method comprising the following steps: a) Measure at least three magnetic field values ​​of the magnetic field described in (1201); b) Determine at least two magnetic field gradients, or at least two or at least three magnetic field differences, based on the at least three magnetic field values; c) Derive (1203) a first signal indicating the position of the position sensor device from the at least two magnetic field gradients or from the at least two magnetic field differences; d) A second signal (1204) indicating the fault and integrity of the position sensor system is derived from the at least two magnetic field gradients or from the at least two magnetic field differences.

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