Method and device for measuring mechanical force

Abstract

Sensor device for sensing a mechanical force, comprising: a substrate comprising one or more magnetic sensors (M1, M2, M3); an elastomer having a first surface area (111) fixedly arranged with respect to the substrate and having a second surface area (112) for receiving the force (F); a magnetic material (104) arranged inside the elastomer such that the magnetic material will move when the force is exerted on the second surface area (112); one or more pressure or stress sensors (P1, P2, P3) for sensing a pressure or stress caused by the force (F); a processing circuit (1130) for determining one or more force components of the force (F) exerted on the second surface area (112) based on sensor signals from the magnetic sensors and / or the pressure sensors; the magnetic sensors and the pressure sensors having a fixed relative position. Method (1000) of measuring a force.

Description

Technical Field

[0001] The present invention generally relates to the field of methods and devices for measuring mechanical forces, and more specifically, to methods and force sensors or tactile sensors that can be used for grasping and / or lifting objects in industrial and robotic applications. Background Technology

[0002] Tactile sensors for industrial and robotic applications are known in the art. They may include, for example, piezoresistive, piezocapacitive, piezoelectric, or barometric pressure sensing elements. Robotic grippers comprising two or more fingers, which may include such tactile sensors, can be used to grasp and lift objects.

[0003] Different types of sensor devices exist, each with its own advantages and disadvantages in terms of sensitivity, cost, size, accuracy, measurement range, robustness to external influences, and error detection capability. Often, two or more of these requirements conflict, and a compromise is chosen.

[0004] There is always room for improvement or replacement. Summary of the Invention

[0005] The purpose of embodiments of the present invention is to provide a sensor device, such as a force sensor device or tactile sensor device capable of measuring force (e.g., capable of measuring one force component (e.g., a force component perpendicular to the substrate, also called a "normal force component"), or two force components (e.g., two shear force components, or a normal force component and a shear force component), or three force components (e.g., a normal force component and two shear force components)).

[0006] Another object of embodiments of the present invention is to provide a method for measuring force (e.g., measuring one force component, two force components, or three force components of the force).

[0007] The object of embodiments of the present invention is to provide a method and apparatus for measuring force with high or increased accuracy or sensitivity (especially for relatively small forces) over a high or increased measurement range. Such a method or apparatus is capable of measuring both relatively small and relatively large forces with good or comparable accuracy. Improved accuracy may apply to at least one force component, or to at least two force components, or to at least three force components. Improved accuracy may be associated with reduced hysteresis.

[0008] The purpose of embodiments of the present invention is to provide a method and / or a device that has improved reliability, robustness or confidence in measurement, for example by providing an output that may be slightly inaccurate but is highly insensitive to external disturbances (e.g., external magnetic fields).

[0009] The purpose of embodiments of the present invention is to provide a method and / or a device that is capable not only of measuring force, but also of detecting errors (e.g., inconsistencies or defects or unreliable measurements).

[0010] These and other objectives are achieved through embodiments of the present invention.

[0011] According to a first aspect, the present invention provides a sensor device for sensing mechanical forces (e.g., for sensing one or more components of said mechanical force), the sensor device comprising: a substrate (e.g., a semiconductor substrate or a printed circuit board) including one or more magnetic sensors (e.g., at least three 2D magnetic pixels, or at least four 2D magnetic pixels, or at least three 3D magnetic pixels, or at least four 3D magnetic pixels) for sensing one or more characteristics of a magnetic field and for providing one or more first sensor signals (e.g., a first set of at least three sensor signals (e.g., m1, m2, m3)); an elastomer having a first surface region fixedly disposed relative to the substrate (e.g., directly or indirectly fixedly connected to said substrate) and a second surface region for receiving said force to be measured; a magnetic material (e.g., a permanent magnet and / or magnetic powder and / or magnetic particles) for generating said magnetic field, said magnetic material being disposed or embedded within the elastomer such that when said force is applied to the second surface region, the magnetic material will move; One or more pressure or stress sensors (e.g., at least one pressure sensor, or at most one pressure sensor, or at least three pressure or stress sensors (e.g., P1, P2, P3)) are arranged to (e.g., directly or indirectly) sense pressure or stress caused by the force, and are configured to provide one or more second sensor signals (e.g., a set of at least three sensor signals (e.g., p1, p2, p3)); processing circuitry is configured to determine one or more force components of the force applied to the second surface region based on the one or more first sensor signals and the one or more second sensor signals (e.g., based on a first set of at least three sensor signals and based on a second set of at least three sensor signals). These components may be: (e.g.,) a single force component (e.g., a normal force component, or a shear force); or two force components (e.g., a normal force component and a shear force); or two shear force components; or three orthogonal force components Fx, Fy, Fz); and wherein one or more magnetic sensors and one or more pressure or stress sensors have fixed positions relative to each other.

[0012] The advantage of using "magnetic sensing" is that such sensors can measure very small forces with high sensitivity (albeit within a relatively small measurement range). This is then beneficial when the sensor is used for touching (e.g., grasping, clamping) delicate objects. The advantage of using "pressure sensing" is that such sensors can measure over a relatively high measurement range (albeit with reduced sensitivity). By using both sensor types in a single device, the sensor device of the present invention combines the advantages of both. To the inventors' knowledge, a combination of magnetic and pressure sensors does not yet exist. But even so, the present invention is not merely a combination of two prior art technologies, but also, in the preferred embodiment, adds error detection capability and / or more reliable measurements compared to existing sensor devices.

[0013] The advantage of such sensor devices (e.g., force sensors or tactile sensors) is that they can measure force with increased accuracy, and / or with increased sensitivity, and / or over a wider measurement range. These sensor devices are well-suited for use as "tactile sensors" in robotic applications.

[0014] Another advantage is that by using two different types of sensors, one or more force components can be measured in a redundant manner, which allows for error detection within at least a portion of the measurement range and / or allows for more robust detection (e.g., pressure sensors are insensitive to magnetic interference fields; but magnetic sensors are also highly insensitive to magnetic interference fields when gradient measurements are used).

[0015] The elastomer is used as a transducer to “transmit” the force applied to the second contact surface to one or more pressure or stress sensors.

[0016] One or more magnetic sensors may be mounted on or embedded in the substrate.

[0017] One or more pressure or stress sensors may also be mounted to or embedded in the substrate.

[0018] One or more pressure or stress sensors may include, for example, one or more piezoresistive sensing elements, piezocapacitive sensing elements, piezoelectric sensing elements, or pneumatic pressure sensing elements. Pressure or stress sensors may include microelectromechanical (MEMS) structures, such as membranes.

[0019] Alternatively, the sensor device may include a second substrate separate from the first substrate but having a fixed position relative to the first substrate, and one or more pressure or stress sensors may be mounted to or embedded in the second substrate.

[0020] If the first substrate and the second substrate are two separate substrates, they are preferably arranged in parallel to each other.

[0021] Preferably, the substrate comprising one or more magnetic sensors (also referred to as the “substrate” or “first substrate”) is a rigid substrate (e.g., a semiconductor substrate, a semiconductor die, or a printed circuit board).

[0022] Preferably, the second substrate, which includes one or more pressure or stress sensors, is a rigid substrate (e.g., a semiconductor substrate, a semiconductor die, or a printed circuit board).

[0023] In the embodiments, the first substrate including one or more magnetic sensors and the second substrate including one or more pressure or stress sensors are the same semiconductor substrate, i.e., a single semiconductor substrate, such as a single semiconductor die, as shown in Figures 1 to 12. Figure 4 , Figure 14 , Figure 15 As shown in the diagram.

[0024] In this embodiment, the first substrate including one or more magnetic sensors and the second substrate including one or more pressure or stress sensors are the same printed circuit board (PCB), i.e., a single PCB, such as... Figure 7A or Figure 7B or Figure 14 As shown in the diagram.

[0025] In this embodiment, a first substrate including one or more magnetic sensors and a second substrate including a pressure or stress sensor are two separate substrates, wherein the first substrate is a semiconductor substrate and the second substrate is a printed circuit board (PCB), such as... Figure 5 and Figure 6 As shown in the diagram.

[0026] In this embodiment, the first substrate and the second substrate are two separate semiconductor substrates, which are integrated into a single semiconductor package (chip) (e.g., as shown in the image). Figure 16 or Figure 17 (See illustration in the image).

[0027] In this embodiment, the first substrate and the second substrate are two separate semiconductor substrates, bonded in two separate semiconductor packages (chips), and mounted on opposite sides of a third substrate (e.g., a printed circuit board). Figure 18 or Figure 19 (See illustration in the image).

[0028] In an embodiment, the at least three magnetic sensors may include three 2D magnetic pixels, or four 2D magnetic pixels, or three 3D magnetic pixels, or four 3D magnetic pixels.

[0029] If the sensor device is implemented, for example, in a chip, module, or printed circuit board, the chip, module, or printed circuit board can provide a first output signal indicating the measured force or one or more force components to an external system controller (e.g., an ECU (Electronic Control Unit)). If the system controller is provided (e.g., mounted) on the same module or PCB, the first output signal indicating the measured force or one or more force components can still be output by processing circuitry, but does not necessarily have to be output by the PCB.

[0030] In an embodiment, the sensor device is configured to measure a single force component, such as Fz oriented in a direction perpendicular to or substantially perpendicular to the substrate.

[0031] In one embodiment, the sensor device is configured to measure three orthogonal force components.

[0032] In some embodiments, the sensor device is configured to detect the strength of a magnetic interference field and / or to detect a mismatch between values ​​(magnetic versus pressure) given by two types of transducers. Upon such detection, the sensor device can provide a warning message and / or cease trusting the value provided by the magnetic sensor, relying solely on the value obtained from the pressure sensor (even for relatively small forces), resulting in a loss of resolution / accuracy, but still returning accurate values. Such sensor devices are highly robust.

[0033] One or more pressure or stress sensors may be located at the first surface region, but this is not strictly necessary. For example, they may be arranged below the first surface region but functionally connected to the first surface region (e.g., via a portion of a plastic mold or via a certain amount of air or gas trapped between the pressure / stress sensor and the elastomer). The gas may be nitrogen or other suitable gas.

[0034] Pressure or stress sensors can be in direct or indirect mechanical contact with an elastomer, such as direct mechanical contact with an elastomer (e.g., ...). Figure 4 , Figure 6 (as illustrated in Figure 1), for example, through indirect mechanical contact via plastic molding compound (e.g., as shown in Figure 1). Figure 2 , Figure 5 (as illustrated in the diagram), for example, indirect mechanical contact via an enclosed amount of air or gas (e.g., in...). Figure 7BIn a variant where the pressure sensor is located inside a cavity, for example, there is indirect mechanical contact between an enclosed quantity of air or gas and a plastic molding compound (not shown). If the contact is indirect via a quantity of air or gas, the force applied to the elastomer will first compress the quantity of air or gas, and this compressed air or gas will exert pressure on the pressure or stress sensor. When a force is applied to the elastomer, the gas will be compressed and will transmit the force or stress on the pressure / stress sensor.

[0035] In this embodiment, the number of magnetic sensors (#MS) is only one, and the number of pressure or stress sensors (#PS) is only one.

[0036] In the embodiment, #MS is one, and #PS is at least two.

[0037] In the embodiment, #MS is one, and #PS is at least three.

[0038] In the embodiment, #MS is two, and #PS is only one.

[0039] In the embodiments, #MS is two, and #PS is only two or at least two.

[0040] In the embodiments, #MS is two, and #PS is only three or at least three.

[0041] In the embodiment, #MS is three, and #PS is only one.

[0042] In the embodiments, #MS is three, and #PS is only two or at least two.

[0043] In the embodiment, #MS is three, and #PS is only three or at least three.

[0044] In the embodiment, #MS is four, and #PS is only one.

[0045] In the embodiments, #MS is four, and #PS is only two or at least two.

[0046] In the embodiments, #MS is four, and #PS is only three or at least three.

[0047] In the embodiment, #MS is at least four, and #PS is only one.

[0048] In the embodiments, #MS is at least four, and #PS is only two or at least two.

[0049] In the embodiments, #MS is at least four, and #PS is only three or at least three.

[0050] In this embodiment, the number of magnetic sensors is at least three, and the number of pressure or stress sensors is only one.

[0051] In this embodiment, the number of magnetic sensors is at least three, and the number of pressure or stress sensors is at least three.

[0052] In this embodiment, the number of magnetic sensors is equal to the number of pressure sensors or stress sensors.

[0053] In this embodiment, the number of magnetic sensors differs from the number of pressure sensors or stress sensors.

[0054] In embodiments, one or more magnetic sensors are one or more detection coils or inductors, such as planar coils, implemented, for example, in a multilayer printed circuit board or in an "interconnect stack" (sometimes also called a "metal stack") on a semiconductor substrate. The one or more detection coils can be configured to sense one or more characteristics of an alternating magnetic field. In this case, the magnetic material can be a conductive magnetic material, such as a conductive soft magnetic material, or a conductive ferromagnetic material. The conductive magnetic material can be arranged to indirectly generate a secondary magnetic field in response to a primary magnetic field generated by one or more excitation coils, which can also be implemented in the printed circuit board or in the "interconnect stack" on the semiconductor substrate. The one or more excitation coils can be located near the detection coils.

[0055] In one embodiment, one or more magnetic sensors are horizontal Hall elements, and one or more stress sensors include one or more piezoelectric strips, such as multiple piezoelectric strips arranged around the respective horizontal Hall element. In this embodiment, the stress sensor is located at the same location as the magnetic sensor.

[0056] In one embodiment, the sensor device includes only one permanent magnet.

[0057] In the embodiments, the magnet is a bipolar magnet or a quadrupole magnet.

[0058] Magnets can have a cylindrical shape, a disk shape, or a prism shape with a polygonal cross-section (e.g., triangular, square, hexagonal, octagonal) in a plane parallel to the substrate.

[0059] A magnet can be magnetized in a direction perpendicular to the substrate.

[0060] In one embodiment, the magnet may have a cylindrical shape with a predefined radius Rm, and the magnetic sensor is arranged on a first virtual circle with a radius R1. The ratio (R1 / Rm) may be a value in the range of 0.5 to 2.0, or from 0.8 to 1.2.

[0061] In one embodiment, the orthogonal projection of the center of the magnet onto the substrate (e.g., a single substrate or a first substrate) substantially coincides with the orthogonal projection of the center of the first circle (on which the magnetic sensor is located) onto the substrate.

[0062] In one embodiment, the orthogonal projection of the center of the magnet onto the substrate substantially coincides with the orthogonal projection of the center of the second circle (on which the pressure or stress sensor is located) onto the substrate.

[0063] In one embodiment, the semiconductor substrate may be at least partially surrounded by a plastic molding compound. An elastomer may be applied on top of the plastic molding compound, and the elastomer may be in direct mechanical contact with the pressure / stress sensor (e.g., via an opening in the plastic molding compound), or may be indirect mechanically contacted with the pressure / stress sensor via the plastic molding compound.

[0064] In this embodiment, the substrate is a semiconductor substrate. One or more (e.g., at least three) magnetic sensors may be embedded in the semiconductor substrate. One or more (e.g., at least three) pressure sensors or stress sensors may also be embedded in the semiconductor substrate.

[0065] In an embodiment, the semiconductor device may include a lead frame and / or multiple leads (also referred to as pins).

[0066] In an embodiment, the orthogonal projection of the periphery of the elastomer onto a plane parallel to the substrate is larger than the orthogonal projection of the periphery of the molding compound, for example, as shown in the example. Figure 5 As shown in the diagram.

[0067] In an embodiment, the orthogonal projection of the periphery of the elastomer onto a plane parallel to the substrate is smaller than the orthogonal projection of the periphery of the molding compound, as illustrated in Figure 1.

[0068] In this embodiment, the semiconductor substrate is surrounded by a plastic molding compound (also referred to as an "encapsulation"), and an elastomer is positioned on top of the molding compound. The molding compound can be in direct contact with a magnetic sensor, and can also be in direct contact with a pressure sensor or stress sensor, and the elastomer can be in direct contact with the molding compound, for example, as... Figure 1A and Figure 2 As illustrated in the diagram, the elastomer can thus have indirect mechanical contact with a pressure sensor or stress sensor.

[0069] In an embodiment, the molded package may have a recess positioned above the semiconductor substrate, and an elastomer may be positioned within and above the recess (e.g., as shown in the image). Figure 2 or Figure 3 (As illustrated in the diagram). The elastomer can be in direct contact with the pressure sensor or stress sensor (e.g., as shown in the diagram). Figure 3(as shown in the diagram), or it can be indirectly connected to a pressure sensor (e.g., as shown in the diagram). Figure 2 (See illustration in the image).

[0070] In one embodiment, the molded package may have a recess positioned above a semiconductor substrate, and an elastomer may be applied over the recess, and a certain amount of air or gas may be contained within the recess. During use, the cavity may serve as a compression chamber, and the air or gas inside the chamber may transmit mechanical force or pressure to a pressure or stress sensor.

[0071] In a preferred embodiment, the sensor device further includes at least one temperature sensor. This temperature sensor may be integrated into the semiconductor substrate or may be a discrete temperature sensor. The processing circuitry may be configured to estimate the temperature of the elastomer based on the measured temperature and to take this estimated temperature into account when determining the force applied to the elastomer. Indeed, the elastomer may become more flexible at higher temperatures, so the magnet displacement may be temperature-dependent.

[0072] In this embodiment, the substrate is a printed circuit board (PCB), and one or more (e.g., at least two or at least three) magnetic sensors are incorporated in a first packaged device mounted on the PCB, and one or more (e.g., at least two or at least three) pressure sensors are discrete components also mounted on the PCB, for example, arranged around the first packaged device (e.g., as shown in the image). Figure 5 and Figure 6 (See illustration in the image).

[0073] In this embodiment, the substrate is a printed circuit board (PCB), and each of the one or more magnetic sensors and each of the one or more pressure sensors are discrete components mounted on the PCB (e.g., such as...). Figure 7B (See illustration in the image).

[0074] In an embodiment, some or all of one or more magnetic sensors or “magnetic sensor units” are one-dimensional (1D) magnetic pixels, such as horizontal Hall elements, each Hall element being configured to measure the magnetic field component Bz at a corresponding location.

[0075] In embodiments, some or all of the one or more magnetic sensors or “magnetic sensor units” are two-dimensional (2D) magnetic pixels. Each such magnetic sensor unit may, for example, include two vertical Hall elements configured to measure the Bx and By components. Alternatively, each such magnetic sensor unit may, for example, include an integrated magnetic concentrator (IMC) and two horizontal Hall elements arranged 180° apart near the periphery of the IMC.

[0076] In embodiments, some or all of the one or more magnetic sensors or "magnetic sensor units" are three-dimensional (3D) magnetic pixels. Each such magnetic sensor unit may, for example, include a horizontal Hall element and two or four vertical Hall elements located in or around the horizontal Hall element. Alternatively, each such magnetic sensor unit may, for example, include a circular IMC and four horizontal Hall elements arranged near the periphery of the IMC and spaced apart at multiples of 90°.

[0077] In this embodiment, the second surface region has a dome shape. Such a surface region may be very suitable for gripping applications.

[0078] In an embodiment, the substrate includes the one or more magnetic sensors, and also includes the one or more pressure or stress sensors. The substrate may also be referred to as a "single substrate" or a "single semiconductor substrate".

[0079] In an embodiment, the substrate including the one or more magnetic sensors is a first substrate, and the sensor device further includes a second substrate, and the second substrate includes the one or more pressure or stress sensors.

[0080] In an embodiment, the first substrate is a first semiconductor substrate, and the second substrate is a second semiconductor substrate. One or more magnetic sensors (e.g., M1, M2, M3) are embedded in the first semiconductor substrate, and one or more pressure or stress sensors (e.g., P1, P2, P3) are embedded in the second semiconductor substrate. Examples of such sensor devices include... Figures 1A to 4 ,as well as Figure 14 and Figure 15 As shown in the image.

[0081] The first and second substrates can be a single semiconductor substrate, such as a single silicon substrate, like a single CMOS die. This single substrate can be overmolded to form a packaged semiconductor device (also known as a "chip").

[0082] The first and second substrates can be two separate substrates incorporated in a single package device, such as two semiconductor dies. These substrates can be mounted on top of each other, for example, on the top side of a lead frame (e.g., as shown in the image). Figure 16 (as illustrated in the diagram), or the second substrate can be mounted on the top side of the lead frame, and the first substrate can be mounted on the bottom side of the lead frame (e.g., as shown in the diagram). Figure 17 (See illustration in the image).

[0083] The first substrate and the second substrate can be two separate substrates, such as two semiconductor dies. The first substrate can be incorporated into a first semiconductor chip, and the second substrate can be incorporated into a second semiconductor chip. The first chip can be mounted on the upper side of a third substrate (e.g., a printed circuit board or a flexible substrate), and the second chip can be mounted on the lower side of the third substrate (e.g., the PCB or the flexible substrate), for example... Figure 18 and Figure 19 As shown in the diagram.

[0084] In one embodiment, the substrate including one or more magnetic sensors is a semiconductor substrate, and the one or more magnetic sensors are embedded in the semiconductor substrate, and the semiconductor substrate is incorporated in a packaged device, and one or more pressure or stress sensors are discrete components surrounding the packaged device.

[0085] The second substrate can be a printed circuit board (PCB). Preferably, the packaged device is an integrated semiconductor device (also known as a "chip").

[0086] The elastomer can be in direct or indirect physical contact with the packaged device and / or with the pressure / stress sensor.

[0087] Figure 5 or Figure 6 The middle figure illustrates an example of such an embodiment. The packaged device and pressure sensor can be mounted on a second substrate (e.g., a printed circuit board (PCB)). The packaged device can have a closed upper surface, or an upper surface with cavities or openings (e.g., as shown in the figure). Figure 6 (As illustrated in the figure). The opening may be completely filled with the elastomer, or it may be partially filled with the elastomer and partially filled with air or gas.

[0088] In an embodiment, the substrate including one or more magnetic sensors is a first substrate, and the sensor device further includes a second substrate, which is a semiconductor substrate including one or more pressure or stress sensors, and the second substrate is incorporated in a package device, and the one or more magnetic sensors are discrete components surrounding the package device.

[0089] Preferably, the packaged device is an integrated semiconductor device (also referred to as a "chip"), and preferably, the chip and one or more discrete magnetic sensors are mounted on a printed circuit board (PCB). Examples of such embodiments can be implemented as follows: Figure 5 or Figure 6 A variant in which the first substrate is a PCB.

[0090] In this embodiment, the substrate is a printed circuit board; and one or more magnetic sensors (e.g., M1, M2, M3) and one or more pressure or stress sensors (e.g., P1, P2, P3) are discrete components mounted on the printed circuit board. An example of such an embodiment is illustrated in Figure 7. Preferably, the sensors are located at at least three different locations.

[0091] In an embodiment, the elastomer has an arched or bridge-shaped shape with a hollow cavity and supporting edges or legs, and one or more magnetic sensors (e.g., M1, M2, M3) are arranged below or inside the cavity, and one or more pressure or stress sensors (e.g., P1, P2, P3) are arranged below the supporting edges or legs.

[0092] In an embodiment, the elastomer has an arched or bridge-shaped shape with a hollow cavity and supporting edges or legs, and one or more magnetic sensors (e.g., M1, M2, M3) and one or more pressure or stress sensors (e.g., P1, P2, P3) are arranged below or inside the cavity.

[0093] The magnetic material or magnetic particles are preferably positioned within the arched portion. When force is applied to such an elastomer, the magnetic material or particles may undergo relatively large displacements, thereby further improving the sensitivity of the sensor device.

[0094] Figure 7B An example with discrete magnetic sensors and discrete pressure sensors is shown.

[0095] exist Figure 7B In some variants, the magnetic sensor is integrated into a single device.

[0096] In one embodiment, an object with a height less than the height of the cavity can be placed at the center of the cavity to limit the displacement of the arched portion. An additional pressure sensor can be positioned below this object.

[0097] In an embodiment (not shown), the sensor device includes at least one sensor unit, or at least two sensor units, or more than three sensor units, each sensor unit including a magnetic sensor and a pressure or stress sensor.

[0098] In an embodiment, the substrate includes at least three magnetic sensors (M1, M2, M3) arranged on a first virtual circle; and the sensor device includes at least three pressure or stress sensors (P1, P2, P3) arranged on a second virtual circle; and the second virtual circle is concentric with the first virtual circle, or the orthogonal projection of the second virtual circle onto the substrate including the first virtual circle is concentric with the first virtual circle.

[0099] In an embodiment, the at least three magnetic sensors and the at least three pressure or stress sensors are mounted to a single substrate and / or embedded in a single substrate.

[0100] In an embodiment, the first virtual circle has a first radius (R1), and the second virtual circle has a second radius (R2); wherein the second radius (R2) is less than, substantially equal to, or greater than the first radius.

[0101] The magnetic sensors can be equidistantly spaced at an angle on the first circle.

[0102] Pressure or stress sensors can be equidistantly spaced at an angle on the second circle.

[0103] In an embodiment, the magnetic material is a permanent magnet, such as a single permanent magnet, and the first radius is less than or equal to the second radius.

[0104] In one embodiment, the first substrate includes at least three or at least four magnetic sensors arranged on a virtual circle or virtual ellipse, and the orthogonal projections of one or more pressure or stress sensors onto the substrate (in a direction perpendicular to the first substrate) are located inside the virtual circle or virtual ellipse.

[0105] Figure 15 An example of such an embodiment is shown in the figure.

[0106] Each magnetic sensor can measure at least two or at least three magnetic field components.

[0107] The sensor device may include three 2D magnetic pixels, or three 3D magnetic pixels, or four 2D magnetic pixels, or four 3D magnetic pixels that are equidistantly spaced on the virtual circle.

[0108] Each 2D magnetic pixel can be capable of measuring a magnetic field component (e.g., Bx or By) parallel to the first substrate and a magnetic field component (e.g., Bz) perpendicular to the first substrate. Each 2D magnetic pixel may include: horizontal Hall elements and vertical Hall elements without an integrated magnetic concentrator (IMC), or may include: a circular IMC disk and two horizontal Hall elements arranged near the periphery of the IMC and spaced apart at an angle of 180°.

[0109] Each 3D magnetic pixel can be capable of measuring two magnetic field components (e.g., Bx and By) parallel to the first substrate and one magnetic field component (e.g., Bz) perpendicular to the first substrate. Each 3D magnetic pixel may include: a horizontal Hall element and two vertical Hall elements positioned such that their principal sensitivity axes are perpendicular to each other; or may include: a circular IMC disk and four horizontal Hall elements arranged near the periphery of the IMC and spaced apart at multiples of 90°.

[0110] In one embodiment, the sensor device includes a single pressure or stress sensor located at the center of a virtual circle.

[0111] In an embodiment, the processing circuit is configured to determine one or more first force components (e.g., a single force component, such as F1z, or a normal force component and a shear force component Fsh, or three force components F1x, F1y, F1z) based on one or more first signals obtained from one or more magnetic sensors; and the processing circuit is configured to determine one or more second force components (e.g., a single force component F2z, or three force components F2x, F2y, F2z) ​​based on one or more second sensor signals obtained from one or more pressure or stress sensors; and the processing circuit is further configured to determine one or more force components of the force (F) applied to the second surface based on one or more first force components and one or more second force components.

[0112] In some embodiments, only the force components oriented perpendicular to the sensor substrate are determined. In other embodiments, three orthogonal force components are determined.

[0113] In one embodiment, the sensor device includes at least two magnetic sensors, and the processing circuitry is configured to determine one or more first force components based on one or more pairwise differences between first sensor signals obtained from the at least two magnetic sensors.

[0114] In an embodiment, the sensor device includes four magnetic sensors (e.g., M1, M2, M3, M4), each capable of measuring three orthogonal magnetic field components (e.g., M1: Bx1, By1, Bz1; M2: Bx2, By2, Bz2; M3: Bx3, By3, Bz3; M4: Bx4, By4, Bz4); and processing circuitry is configured to determine at least two magnetic field differences (e.g., dBxdx, dBydx, dBzdx, dBxdy, dBydy, dBzdz) between the parallel magnetic field components; and processing circuitry is configured to determine one or more first force components (e.g., F1x, F1y; F1z) based on the magnetic field differences.

[0115] For example, F1x can be determined based on one or more magnetic field differences along the X-axis, such as based solely on dBxdx, or solely on dBzdx, or based on both dBxdx and dBzdx, or based on dBxdx, dBydx, and dBzdx (e.g., as shown in the image). Figure 15 (as specified in the text).

[0116] For example, F1y can be determined based on one or more magnetic field differences along the Y-axis, such as based solely on dBydy, or solely on dBzdy, or based on both dBydy and dBzdy, or based on dBxdy, dBydy, and dBzdy (e.g., as shown in the image). Figure 15 (as specified in the text).

[0117] For example, F1z can be determined based on dBzdx and dBzdy, or based on dBzdx, dBzdy, dBxdx, and dBydy (e.g., as shown in the figure). Figure 15 (as specified in the text).

[0118] In an embodiment, the sensor device includes four magnetic sensors (M1, M2, M3, M4), each capable of measuring at least two (or only two) orthogonal magnetic field components (e.g., M1: Bx1, Bz1; M2: By2, Bz2; M3: Bx3, Bz3; M4: By4, Bz4); and processing circuitry is configured to determine at least two magnetic field differences (e.g., dBxdx, dBzdx, dBydy, dBzdy); and further configured to determine one or more first force components (F1x, F1y, F1z) based on the magnetic field differences.

[0119] Examples of such embodiments are Figure 15 The variant, in which H2, H4, H10, H12, H13, H15, H5, and H7 are omitted.

[0120] For example, F1x can be determined based on one or more magnetic field differences along the X-axis, such as only dBxdx, or only dBzdx, or both dBxdx and dBzdx (e.g., as shown in the image). Figure 15 (as specified in the text).

[0121] For example, F1y can be determined based on one or more magnetic field differences along the Y-axis, such as based solely on dBydy, or solely on dBzdy, or based on both dBydy and dBzdy (e.g., as shown in the image). Figure 15 (as specified in the text).

[0122] For example, F1z can be determined based on dBzdx and dBzdy, or based on dBzdx, dBzdy, dBxdx, and dBydy (e.g., as shown in the figure). Figure 15 (as specified in the text).

[0123] In an embodiment, the processing circuit is configured to: if one or more first force components (e.g., F1x, F1y, F1z) are less than a first threshold, determine one or more values ​​of one or more components of the force (F) applied to the second surface (e.g., Fx, Fy, Fz) as the one or more first force components (e.g., F1x, F1y, F1z); or otherwise, determine one or more values ​​of one or more components of the force (F) applied to the second surface (e.g., Fx, Fy, Fz) as one or more second force components (e.g., F2x, F2y, F2z).

[0124] In an embodiment, the processing circuit is configured to determine a first amplitude of a first vector corresponding to one or more first force components (F1x, F1y, F1z), and to test whether the first amplitude is less than a first predefined threshold; and if the result of the test is true (meaning that the first vector is relatively small and therefore no clipping occurs), then the one or more force components of the force to be measured are determined only based on the one or more first force components; and if the result of the test is false (meaning that the first vector is relatively large), then the one or more force components of the force to be measured are determined only based on one or more second force components.

[0125] In an embodiment, if a single force component (e.g., Fz) is measured, this means that Fz is set to F1z (if the value is less than a predefined threshold), or otherwise set to F2z. In an embodiment where three force components are measured, this means that if the magnitude of the vector (Fx, Fy, Fz) is less than a predefined threshold, then the value of (Fx, Fy, Fz) is set to be equal to (F1x, F1y, F1z), or otherwise set to be equal to (F2x, F2y, F2z).

[0126] In a variant, the processing circuit is configured to determine a single first force component (e.g., F1z) and a single second force component (e.g., F2z), and to test whether the second force component is greater than a predefined threshold. If the test result is true, the force to be measured is determined to be the second force component (e.g., F2z); and if the test result is false, the force to be measured is determined to be the first force component (e.g., F1z).

[0127] In a variant, the processing circuit is configured to determine the maximum value from the second set of three force components (F2x, F2y, F2z), and to test whether the maximum value is greater than a predefined threshold. If the test result is true, one or more force components (Fx, Fy, Fz) of the force (F) are determined to be one or more components from the second set of force components (F2x, F2y, F2z); otherwise, one or more force components (Fx, Fy, Fz) of the force (F) are determined to be one or more components from the first set of force components (F1x, F1y, F1z).

[0128] In an embodiment, the processing circuit is configured to determine one or more values ​​of one or more force components (Fx, Fy, Fz) of the force (F) applied to the second surface as a combination (e.g., linear combination, average value, weighted average value) of a first force component (F1z) or a component value of a first component quantity (F1x, F1y, F1z) (on one hand) and a component value of a corresponding component of a second force component (F2z) or a second component quantity (F2x, F2y, F2z).

[0129] In this embodiment, the values ​​of (Fx, Fy, Fz) can be calculated according to one or more of the following formulas: Fx = w11 F1x+w12 F2x; Fy=w21 F1y+w22 F2y;Fz=w31 F1z+w32 F2z, where w11 to w32 are predefined weighting factors that can be determined during the calibration process. These weighting factors can depend on the shape and size of the elastomer and the relative position of the sensor elements.

[0130] In an embodiment, the sensor device is configured to determine and output three orthogonal force components (e.g., Fx, Fy, Fz), which include a normal force component (e.g., Fz) and two shear force components (e.g., Fx, Fy).

[0131] In an embodiment, the sensor device is configured to determine and output two shear force components (e.g., Fx, Fy).

[0132] In an embodiment, the sensor device is configured to determine and output a normal force component (e.g., Fz) and a single shear force component (e.g., Fsh).

[0133] In an embodiment, the sensor device is configured to determine and output a single shear force component (e.g., Fsh).

[0134] The individual shear force component Fsh can be calculated using the following formula:

[0135] Fsh = sqrt[sqr(Fx) + sqr(Fy)], where sqrt() is the square root function and sqr() is the square function.

[0136] In an embodiment, a single shear force component (e.g., Fsh) or two (e.g., orthogonal) shear force components (e.g., Fx, Fy) are derived from signals obtained from one or more magnetic sensors (or solely from signals obtained from one or more magnetic sensors), optionally taking into account measured temperature values.

[0137] In the latter case, the sensor device may further include a temperature sensor for measuring the temperature of the first substrate or the second substrate as an estimate of the temperature of the elastomer.

[0138] In an embodiment, the normal force component is determined based on signals obtained from both the one or more magnetic sensors and the one or more pressure or stress sensors, optionally taking into account the measured temperature value.

[0139] In an embodiment, the normal force component (e.g., Fn) is determined as a weighted average of the first force component (F1z) and the second force component (F2z) using a predefined weighting factor or a temperature-related weighting factor.

[0140] For example, according to the following formula: Fn=w1 F1z + w2 F2z, where w1 and w2 are weighting factors, which can be predefined constants or functions of temperature, and can be stored in non-volatile memory in any suitable manner, such as in the form of one or more lookup tables, or as coefficients of a polynomial expression.

[0141] In an embodiment, the normal force component (e.g., Fn) is determined as a weighted average of a first normal force component F1z derived from a magnetic field difference signal and a second normal force component F2z derived from one or more pressure signals, wherein the weighting factor is optionally temperature-dependent.

[0142] In an embodiment, the processing circuitry is configured to perform a consistency test between one or more first sensor signals obtained from one or more magnetic sensors and one or more second sensor signals obtained from one or more pressure / stress sensors, or between one or more first force components (e.g., F1x, F1y, F1z) and one or more second force components (e.g., F2x, F2y, F2z); and if an inconsistency is detected, the one or more force components (Fx, Fy, Fz) of the force to be measured are determined based solely on the one or more second force components (e.g., F2x, F2y, F2z).

[0143] In an embodiment, the sensor device may optionally provide an error signal based on the result of the conformance test. This error signal may be output by the sensor device or may be transmitted (e.g., to another processor, such as an ECU).

[0144] The results of the conformance test can be provided as an error signal. For example, if the sensor device is implemented in a chip, module, or printed circuit board, the chip, module, or printed circuit board can provide a first output signal indicating the measured force component and a second output signal indicating the error.

[0145] In an embodiment, such a consistency test may include: 1) testing whether each force component (F1x, F1y, F1z) in the first set of force components is less than the corresponding value in the first set of predefined thresholds (T1x, T1y, T1z); and if the result of the test is true (meaning that all values ​​are relatively small and no clipping or saturation has occurred), then testing the consistency between T1x and T2x, and testing the consistency between T1y and T2y, and testing the consistency between T1z and T2z, for example by testing whether these values ​​deviate from a predefined absolute value, and / or by testing whether these values ​​deviate from a predefined percentage, for example by testing whether the ratio of T1x / T2x is a value within a predefined range, such as, for example, in the range from 80% to 120%, or in the range from 90% to 110%, or in the range from 95% to 105%. If at least one of the component values ​​(e.g., F1x) is greater than its corresponding first threshold (e.g., T1x), other pairwise consistency tests (e.g., consistency tests between F2y and T2y, and / or between F2z and T2z) can be skipped.

[0146] In an embodiment, the processing circuit is configured to determine the presence of a magnetic interference field (e.g., by measuring a magnetic field greater than that generated by a magnetic material (e.g., a magnet in an elastomer); and if a magnetic interference field of at least a predefined magnitude is detected, to determine one or more (e.g., three) force components (Fx, Fy, Fz) of the force (F) based solely on one or more second force components (F2x, F2y, F2z).

[0147] In an embodiment, the processing circuit is also configured to detect the presence of a magnetic interference field, for example by determining the amplitude of a magnetic field measured by any of the magnetic sensors, and to determine the presence of a magnetic interference field if the measured amplitude value is greater than a predefined maximum value.

[0148] According to a second aspect, the present invention also provides a robotic gripper comprising two or more movable elements (e.g., robotic fingers), each movable element comprising at least one sensor device according to the first aspect.

[0149] According to a third aspect, the present invention also provides a method for determining one or more (e.g., only one, only two, or three) force components (e.g., Fx, Fy, Fz) of a force (F) using a sensor device according to the first aspect, the method comprising the steps of: a) receiving one or more first sensor signals (e.g., m1, m2, m3) from one or more magnetic sensors (e.g., M1, M2, M3), and determining one or more first force components (e.g., F1z; F1x, F1y, F1z) based on the one or more first signals (e.g., m1, m2, m3); b) receiving one or more pressure sensors (e.g., M1, M2, M3) from one or more magnetic sensors (e.g., M1, M2, M3); and determining one or more first force components (e.g., F1z; F1x, F1y, F1z) based on the one or more first signals (e.g., m1, m2, m3); A force or stress sensor (e.g., P1, P2, P3) receives one or more second sensor signals (e.g., s1, s2, s3) and determines one or more second force components (e.g., F2z; F2x, F2y, F2z) ​​based on the one or more second sensor signals (e.g., s1, s2, s3); c) determines one or more force components (e.g., Fz; Fx, Fy, Fz) of the force to be measured based on the one or more first force components (e.g., F1x, F1y, F1z) and the one or more second force components (e.g., F2x, F2y, F2z).

[0150] In an embodiment, step a) includes: determining a first force component (e.g., F1z) or a first set of force components (e.g., F1x, F1y, F1z) based on the pairwise differences between the first set of signals (e.g., m1, m2, m3).

[0151] In an embodiment, step a) includes: determining a first force component (e.g., F1z) oriented in a direction perpendicular to the substrate; and step b) includes: determining a second force component (e.g., F2z) ​​oriented in the direction perpendicular to the substrate; and step c) includes: determining the force to be measured as the first force component (e.g., F1z) if the value of the first force component (e.g., F1z) is less than a first predefined threshold.

[0152] In an embodiment, step a) includes: determining a first force component (e.g., F1z) oriented in a direction perpendicular to the substrate; and step b) includes: determining a second force component (e.g., F2z) ​​oriented in the direction perpendicular to the substrate; and step c) includes: if the second force component (e.g., F2z) ​​is greater than a second predefined threshold, then determining the force to be measured as the second force component (e.g., F2z).

[0153] In an embodiment, step a) includes: determining a first set of three force components (e.g., F1x, F1y, F1z); and step b) includes: determining a second set of three force components (e.g., F2x, F2y, F2z); and step c) includes: if each value in the first set of force components is less than a first predefined threshold, then the force to be measured is determined as the first set of force components; and otherwise, the force to be measured is determined as the second set of force components.

[0154] In an embodiment, step a) includes: determining a first set of three force components (e.g., F1x, F1y, F1z); and step b) includes: determining a second set of three force components (e.g., F2x, F2y, F2z); and step c) includes: if at least one of the values ​​of the second set of force components is greater than a second predefined threshold, then the force to be measured is determined as a second set of force components; and otherwise, the force to be measured is determined as a second set of force components.

[0155] In an embodiment, step a) includes: determining a first group of three force components (e.g., F1x, F1y, F1z); and step b) includes: determining a second group of three force components (e.g., F2x, F2y, F2z); and step c) includes: if the value of a corresponding component from the first group of force components is less than a first predefined threshold, then each component of the force to be measured is determined as a corresponding component from the first group of force components; and otherwise, each component of the force to be measured is determined as a corresponding component from the second group of force components.

[0156] In an embodiment, the method further includes the following steps: performing a consistency check between the first set of sensor signals and the second set of sensor signals, and / or between the first force component (e.g., F1z) and the second force component (e.g., F2z), or between the first set of force components (e.g., F1x, F1y, F1z) and the second set of force components (e.g., F2x, F2y, F2z), and providing the result of the consistency check (e.g., an error signal).

[0157] In an embodiment, the method further includes the steps of: measuring or estimating the temperature of the elastomer; and step a) includes: taking into account the temperature (e.g., taking into account the temperature-dependent flexibility of the elastomer) to determine the first component or the first set of force components.

[0158] Specific and preferred aspects of the invention are set forth in the appended independent and dependent claims. Features from the dependent claims may be appropriately combined with features of the independent claims and other dependent claims, and not merely as expressly set forth in the claims.

[0159] These and other aspects of the invention will be apparent from the embodiments(s) described herein, and are illustrated with reference to the embodiments(s) described herein. Attached Figure Description

[0160] Figure 1A This is a cross-sectional view of an illustrative example of a force sensor device according to an embodiment of the present invention. The device includes an elastomer, a magnetic material in the form of a magnet, one or more (e.g., at least three) magnetic sensors, and one or more (e.g., at least three) pressure / stress sensors. Figure 1A In the example, one or more magnetic sensors and one or more pressure / stress sensors are integrated in a single semiconductor substrate.

[0161] Figure 1B The top view shows, for example, what can be seen in Figure 1A An illustrative example of the semiconductor substrate used shows a possible arrangement of three magnetic sensors on the inner ring and three pressure / stress sensors on the outer ring.

[0162] Figure 1A and Figure 1B They can be collectively referred to as Figure 1.

[0163] Figures 2 to 6 This is a cross-sectional view of another illustrative example of a force sensor device according to an embodiment of the present invention.

[0164] Figure 7AA top view of another illustrative example of a force sensor device according to an embodiment of the present invention is shown, and Figure 7B A cross-sectional view of another illustrative example of a force sensor device according to an embodiment of the present invention is shown.

[0165] Figure 7A and Figure 7B They can be collectively referred to as Figure 7.

[0166] Figure 8 A graph is shown with a first illustrative curve (in arbitrary units) and a second illustrative curve. The first illustrative curve shows one component of a first set of force components (F1x, F1y, F1z) that can be derived from the signal obtained from the magnetic sensor, and the second illustrative curve shows one component of a second set of force components (F2x, F2y, F2z) ​​that can be derived from the signal obtained from the pressure / stress sensor.

[0167] Figure 9 It shows Figure 8 The graph shows the curves and indicators of certain thresholds and regions.

[0168] Figure 10A , Figure 10B and Figure 10C A flowchart of a method for measuring force according to an embodiment of the present invention is shown, for example using the method shown in Figures 1 to 12. Figure 7B Any of the sensor devices shown in the diagram, or those using... Figures 14 to 19 The sensor device shown in the diagram.

[0169] Figure 10A , Figure 10B and Figure 10C They can be collectively referred to as Figure 10.

[0170] Figure 11 An illustrative example of a high-level block diagram of a sensor device is shown, which includes one or more magnetic sensors and one or more pressure / stress sensors (e.g., as shown in Figures 1 to 1). Figure 7B The system includes the arrangement shown in the diagram, processing circuitry, and optionally includes a temperature sensor and non-volatile memory.

[0171] Figure 12 Another illustrative example of a high-level block diagram of a sensor device is shown, which includes a first processing circuit connected to one or more magnetic sensors, and a second processor circuit connected to the first processing circuit and connected to one or more pressure / stress sensors.

[0172] Figure 13An illustrative example of a force sensor device or force sensor system is shown, comprising: a first sensor device including one or more magnetic sensors; a second sensor device including one or more pressure / stress sensors; and a combiner circuit connected to both the first sensor device and the second sensor device.

[0173] Figure 14 A substrate (e.g., a semiconductor substrate or PCB) comprising four magnetic sensors and one or more pressure / stress sensors is shown, as well as an elastomer comprising a magnet on top of the substrate, as may be used in embodiments of the invention.

[0174] Figure 15 A semiconductor substrate is shown, which includes four magnetic sensors in the form of four 3D magnetic pixels and a pressure / stress sensor, as may be used in embodiments of the present invention.

[0175] Figures 16 to 19 This is a cross-sectional view of another illustrative example of a force sensor device according to an embodiment of the present invention.

[0176] Figure 20 Measurements obtained from experiments in which normal forces were applied and released are shown, demonstrating strong hysteresis.

[0177] Figure 21A Measurements obtained from an experiment in which normal force was repeatedly applied and released are shown, demonstrating strong hysteresis.

[0178] Figure 21B The normal force component, determined to be a combination of the first force component F1z and the second force component F2z, is shown, exhibiting highly linear behavior with significantly reduced hysteresis.

[0179] Figure 21A and Figure 21B They can be collectively referred to as Figure 21.

[0180] Figure 22 It is a data flow diagram that illustrates how signals from one or more magnetic sensors and one or more pressure / stress sensors can be used to calculate one or more force components, such as normal force component Fn and / or shear force components Fx, Fy and / or shear force Fsh.

[0181] These figures are illustrative only and not restrictive. In the figures, some elements may be enlarged and not drawn to scale for illustrative purposes. No reference numerals in the claims should be construed as limiting the scope. In different figures, the same reference numerals refer to the same or similar elements. Detailed Implementation

[0182] The invention will be described with reference to specific embodiments and certain accompanying drawings, but the invention is not limited thereto but is defined only by the claims.

[0183] 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 a temporal, spatial, hierarchical, or any other order. 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 orders other than those described or illustrated herein.

[0184] The terms top, bottom, 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.

[0185] It should be noted that the term "comprising" as used in the claims should not be construed as limiting itself to the means 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 expression "device comprising means A and B" should not be limited to a device consisting solely of components A and B. This means that for the present invention, the only relevant components of the device are A and B.

[0186] 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 apparent to those skilled in the art from this disclosure, particular features, structures, or characteristics may be combined in any suitable manner.

[0187] 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 streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. However, this method of disclosure should not be construed as reflecting an intention to claim more features than are expressly recited in each claim. Rather, as reflected in the appended claims, the inventive aspect lies in fewer features than all the features of a single foregoing disclosed embodiment. Thus, the claims appended to the Detailed Description are thereby explicitly incorporated into this Detailed Description, wherein each claim itself represents a separate embodiment of the invention.

[0188] Furthermore, while some embodiments described herein include features found in other embodiments but not in those other embodiments, combinations of features from different embodiments are intended to fall within the scope of the invention and form different embodiments as will be understood by those skilled in the art. For example, any embodiment of the claimed embodiments in the appended claims may be used in any combination.

[0189] Furthermore, the terms “approximately,” “substantially,” or “about” indicate a range of tolerances that are considered normal by a person skilled in the art. Specifically, unless otherwise expressly stated or unless otherwise specified from the context, the above terms should be understood to include a tolerance range of the indicated quantity, up to a maximum of ±20%, preferably up to a maximum of ±10%.

[0190] 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.

[0191] In this document, the terms "pressure sensor or stress sensor", "pressure or stress sensor", or "pressure / stress sensor" have the same meaning.

[0192] In this document, the term "magnetic sensor element" may refer to a single vertical Hall element, a single horizontal Hall element, or a single magnetoresistive element (e.g., AMR element, GMR element, TRM element, or XMR element).

[0193] In this document, the terms “magnetic sensor” or “magnetic sensor structure” may refer to a set of components or sub-circuits or structures capable of measuring magnetic quantities, such as, for example, a set of at least two magnetic sensor elements, or a Wheatstone bridge containing four MR elements.

[0194] In some embodiments of the invention, the term "magnetic sensor" or "magnetic sensor structure" may refer to an arrangement that includes one or more integrated magnetic concentrators (IMCs) (also referred to as integrated magnetic flux concentrators) and two, four, or eight horizontal Hall elements arranged near the periphery of the IMC.

[0195] In this document, the terms "in-plane component of a vector" and "orthogonal projection of a vector onto the sensor plane" have the same meaning. If the sensor device is or includes a substrate (e.g., a semiconductor substrate or a printed circuit board), this also means "component parallel to the substrate."

[0196] In this document, the terms "out-of-plane component of a vector," "Z-component of a vector," and "orthogonal projection of a vector onto an axis perpendicular to the sensor plane" have the same meaning.

[0197] Embodiments of the present invention are typically described using an orthogonal coordinate system fixed to a sensor device and having three axes X, Y, and Z, wherein the X and Y axes are parallel to the substrate, and the Z axis is perpendicular to the substrate. In the context of the present invention, "substrate" typically refers to a first substrate comprising a plurality of magnetic sensors, unless the context clearly indicates otherwise.

[0198] 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 typically defined as the difference between two values ​​measured at two different locations spaced apart by a predefined distance. Theoretically, the gradient is calculated as the difference between the two values ​​divided by the distance between the sensor locations (e.g., "dx"), but in practice, the division by "dx" is often omitted because the measured signal needs to be scaled anyway.

[0199] In this document, horizontal Hall effect sensors are typically designated by H1, H2, etc., and signals from these horizontal Hall effect sensors are typically designated by h1, h2, etc.; vertical Hall effect sensors are typically designated by V1, V2, etc., and signals from these vertical Hall effect sensors are typically designated by v1, v2, etc.; magnetic sensors are typically designated by M1, M2, etc., and signals from these magnetic sensors are typically designated by m1, m2, etc.; pressure or stress sensors are typically designated by P1, P2, etc., and signals from these sensors are typically designated by p1, p2, etc.

[0200] This invention generally relates to methods and devices for measuring force, such as force sensors or tactile sensors, and more specifically, to force sensors or tactile sensors that can be used in industrial or robotic applications to grasp and lift objects. They can be mounted to robotic fingers and can be used to hold objects between such fingers.

[0201] For ease of description, the present invention will be explained primarily with reference to a sensor device comprising at least three magnetic sensors and at least one pressure / stress sensor, and configured to determine two force components (e.g., a normal force component Fn and a shear force component Fsh) or three force components (e.g., Fx, Fy, Fz). However, the invention is not limited thereto, and is also suitable for using sensor devices having fewer than three magnetic sensors and / or fewer than three pressure or stress sensors to determine at least one force component, such as a single force component Fz.

[0202] Please refer to the attached diagram.

[0203] Figure 1A This is a cross-sectional view of an illustrative example of a force sensor device or tactile sensor device 100. The force sensor device 100 of FIG1 includes an integrated circuit (or “chip”) 107 having a plastic molded package 102, and an elastomer 110 on top of the package. The device 100 further includes a permanent magnet 104 embedded in the elastomer 110. The magnet 104 generates a magnetic field. Figure 1A The integrated circuit 107 includes a semiconductor substrate (e.g., a CMOS substrate) that includes at least three magnetic sensors. Figure 1A Only one of them is visible) and at least three pressure or stress sensors. Figure 1A Only one of them is visible.

[0204] Figure 1B An example of a semiconductor substrate 101 is shown, which includes three magnetic sensors M1, M2, M3 (indicated schematically by squares for illustrative purposes) and three pressure sensors P1, P2, P3 (also indicated schematically by squares for illustrative purposes) embedded in the semiconductor substrate 101 and arranged in a particular manner, but the invention is not limited thereto.

[0205] exist Figure 1B In the example, three magnetic sensors M1, M2, M3 (e.g., horizontal Hall elements) are positioned on a first virtual circle with a first radius R1 and spaced angularly in multiples of 120°; and three stress sensors P1, P2, P3 (e.g., piezoresistive, piezocapacitive, piezoelectric, or barometric pressure sensors) are positioned on a second virtual circle with a second radius R2 and are also spaced angularly in multiples of 120°. Figure 1BIn the example, the second virtual circle is concentric with the first virtual circle, and the second radius R2 is greater than the first radius R1, but the present invention is not limited thereto.

[0206] Reference Figure 1A The elastomer 110 makes mechanical contact with the plastic molded package 102 at the first surface region 111. When no external force is applied to the second surface region 112 of the elastomer, the magnet 104 is in its "rest position" or "default position", and the magnetic sensor measures a first set of signals and the pressure sensor measures a second set of signals, corresponding to the "default magnet position" corresponding to "no external force applied".

[0207] When an external force F is applied to the second surface region 112 of the elastic body 110 (in) Figure 1A In the example, the second surface region 112 is positioned at the top), the elastomer 110 will elastically deform, and the magnet 104 will move slightly (e.g., in...). Figure 1A In the example shown, the magnet will move slightly downwards and to the right. The magnetic sensor will measure different magnetic fields and will provide a different first set of signals corresponding to the new position of the magnet, and thus to the applied external force. Techniques for converting such magnetic signals into three magnetic field components (F1x, F1y, F1z) are known in the art and may involve, for example, a trained artificial neural network (ANN), but the invention is not limited thereto, and other processing circuits or techniques may be used, such as those described in WO2023036900(A1), which is consistent with its overall (particularly its) Figure 22 (a) and Figure 22 (b) and the corresponding algorithm are incorporated herein by reference.

[0208] The force F applied to the elastomer 110, or a portion thereof, will also be sensed by pressure or stress sensors P1, P2, and P3, which will provide another set of second signals corresponding to the applied external force. For example, when a normal force (i.e., a force oriented in the negative Z direction perpendicular to the semiconductor substrate 101) is applied, the three pressure sensors will sense the same pressure value. As another example, when the force has components in both the negative Z and positive X directions, pressure sensors P1 and P3 will sense the same value, but sensor P2 will sense a higher value. It is known in the art how the second set of signals can be converted into a set of orthogonal force components (F2x, F2y, F2z). Since such algorithms are known and not the primary focus of this invention, they need not be explained in more detail here. Simply put, in some embodiments, the force component values ​​(F2x, F2y, F2z) ​​can be calculated using matrix multiplication between a matrix including predefined coefficients (which can be determined during the calibration process) and a matrix including the sensor signals.

[0209] As can be understood from the above, one or more force components (e.g., the first group of three orthogonal force components (F1x, F1y, F1z)) can be derived from the signals obtained from magnetic sensors M1, M2, and M3, and one or more force components (e.g., the second group of three orthogonal force components (F2x, F2y, F2z)) can be derived from the signals obtained from pressure or stress sensors.

[0210] Figure 1A and Figure 1B The force sensor device 100 may further include one or more processing circuits for determining one or more (e.g., three) force component values ​​(Fx, Fy, Fz) of the force applied to the elastic body 110 based on a first set of three orthogonal force component values ​​and a second set of three orthogonal force component values, as will be shown in [the diagram]. Figure 8 This will be further explained in Figure 10.

[0211] exist Figure 1A In the example, the elastomer 110 has a dome-shaped upper surface, but this is not absolutely necessary, and other geometries (such as planar surfaces) can also be used.

[0212] exist Figure 1A In the example, the integrated semiconductor device 107 has a lead frame with leads or pins 103 extending laterally from the package 102, but this is not required and other packages can also be used.

[0213] In another or further variant, the sensor device may include more than three magnetic sensor elements (e.g., four magnetic sensors) and / or more than three pressure or stress sensors, or fewer than three pressure / stress sensors (e.g., only one pressure / stress sensor).

[0214] exist Figure 1A In the example shown, magnet 104 is a solid permanent magnet having, for example, a cylindrical shape with a diameter of D and a height of H, but this is not absolutely necessary, and solid magnets with other shapes can also be used. In other variations (not shown), instead of a solid object or in addition to a solid object, sensor device 100 may include magnetic powder or magnetic particles distributed within elastomer 110.

[0215] In some embodiments, some or all of the “magnetic sensor” or “magnetic sensor unit” may be one-dimensional (1D) magnetic pixels (e.g., horizontal Hall elements or vertical Hall elements), and each “magnetic sensor” or “magnetic sensor unit” is configured to measure a single magnetic field component at the corresponding location, such as measuring Bz in the case of a horizontal Hall element.

[0216] Alternatively or additionally, some or all of the magnetic sensors or “magnetic sensor units” may be two-dimensional (2D) magnetic pixels. Each such magnetic sensor unit may, for example, include two vertical Hall elements, one for measuring the Bx component and one for measuring the By component. Alternatively, each such magnetic sensor unit may, for example, include an integrated magnetic concentrator (IMC) and two horizontal Hall elements spaced 180° apart.

[0217] Alternatively or additionally, some or all of the magnetic sensors or "magnetic sensor units" are three-dimensional (3D) magnetic pixels. Each such magnetic sensor unit may, for example, include a horizontal Hall element and two or four vertical Hall elements positioned adjacent to or around the horizontal Hall element. Alternatively, each such magnetic sensor unit may, for example, include a circular IMC and four horizontal Hall elements arranged near the periphery of the IMC at angular intervals of multiples of 90°.

[0218] In some embodiments of the invention, a first force component (e.g., F1z) or a first set of force components (F1x, F1y, F1z) is derived not only from a magnetic sensor signal, such as that provided by a horizontal Hall element, a vertical Hall element, or a magnetoresistive (MR) element, but also from the difference between parallel field components or from a magnetic field gradient signal. This provides the advantage that the first force component or first set of force components thus determined has improved robustness relative to external disturbance fields.

[0219] The permanent magnet 104 can be an axially magnetized bipolar magnet, for example, having a cylindrical or disk shape. The cylinder can have a diameter D and a height H. The ratio D / R1 can be a value in the range of 0.50 to 2.0, but the invention is not limited thereto.

[0220] exist Figure 1B In a variant (not shown), the radius R1 of the circle located by the magnetic sensor is greater than the radius R2 of the circle located by one or more pressure sensors.

[0221] exist Figure 1A and Figure 1B In a variant (not shown), substrate 101 includes three or four magnetic sensors (e.g., 2D magnetic pixels or 3D magnetic pixels) positioned on a virtual circle having a radius R1, and includes one or more pressure sensors or stress sensors positioned inside the virtual circle, but not necessarily on the second circle; for example, only one pressure sensor or stress sensor may be positioned substantially at the center of the virtual circle.

[0222] Figure 2 This is a cross-sectional view of an illustrative example of another force sensor device or tactile sensor device 200, which can be considered a variant of the force sensor device 100 of FIG1. ​​Except for the shape of the upper surface 212 of the elastomer 210, Figure 2 The main difference between the sensor device 200 and the sensor device 100 of FIG1 is that the molded package 202 of the integrated sensor device 207 (before the elastomer 210 is applied) has a cavity or recess 205 for receiving the bottom of the elastomer 210.

[0223] In this way, the thickness of the upper layer of the molding compound 202 can be reduced, and the risk of the elastomer 210 detaching from the molding package due to shear forces can be reduced. In addition, the magnet 204 can be positioned closer to the substrate 201, thereby allowing for a stronger magnetic field measured by the magnetic sensors M1, M2, and M3, which improves the signal-to-noise ratio (SNR) and thus improves accuracy.

[0224] The above is for Figure 1A and Figure 1B All other descriptions and variations thereof, with necessary modifications, also apply herein. For example, semiconductor substrate 201 may include more than three magnetic sensors, and / or may include more than three or fewer than three pressure / stress sensors, and / or the sensors may be compatible with... Figure 1B The same or different arrangements are shown in the diagram (e.g., as shown in the diagram). Figure 1B (as described in the variants).

[0225] exist Figure 2In a variant (not shown), a cavity is formed between the upper surface of the semiconductor substrate 201 and the elastomer 210, and the cavity is filled with air or gas, which transmits a portion of the force applied to the elastomer. Thus, the elastomer 210 does not need to be in direct physical contact with the pressure or stress sensor, but it can be in direct physical contact with the pressure or stress sensor.

[0226] exist Figure 2 In the variant (not shown), the elastomer 210 has a dome-shaped upper surface.

[0227] Figure 3 A cross-section of another illustrative sensor device 300 is shown. This illustrative sensor device 300 can be considered as a variant of the sensor device 100 of FIG1, or as... Figure 2 A further variant of the sensor device 200, wherein the molded package 302 of the semiconductor device 307 has an opening 308 that exposes the upper surface of the semiconductor substrate 301 before the elastomer 310 is applied, to allow direct physical contact between the elastomer 310 and the upper surface of the substrate without an intermediate molding compound. In this way, the sensitivity of the pressure / stress sensor can be further improved. The above refers to... Figure 2 All other descriptions and their variations, with the necessary modifications, also apply here.

[0228] By comparison Figure 2 and Figure 3 Once this disclosure is published, those skilled in the art who benefit from it will understand that, for a given elastomer, the sensitivity of force measurement using a magnetic sensor can be increased by mounting the magnet 204 closer to the substrate 201, and the sensitivity of force measurement using a pressure / stress sensor can be increased by reducing the thickness Tc of the compound layer between the substrate 201 and the elastomer 210.

[0229] Figure 3 This also illustrates another aspect: semiconductor devices can use stress sensors arranged near magnetic sensors, instead of using... Figure 1B The diagram illustrates three pressure sensors arranged as shown. Depending on the implementation, each pressure sensor can be located near the magnetic sensor or can surround the magnetic sensor (e.g., a horizontal Hall plate). This aspect is independent of the presence of opening 308 and can also be used... Figure 1A Devices or Figure 2 The device is included, but no separate accompanying drawings are provided.

[0230] Figure 4 It shows Figure 3Another variant of the cross-section, in which the orthogonal projection of the elastomer 410 onto the plane containing the substrate 401 is smaller than the size of the substrate 401, and thus also smaller than the contour of the molded package 402. In contrast, in Figure 1A , Figure 2 and Figure 3 In the device illustrated, the orthogonal projection of the elastomer onto the plane containing the semiconductor substrate is larger than the semiconductor substrate but smaller than the outline of the molded package. However, the invention is not limited to any of the above, and the projection or footprint of the elastomer may also be larger than the outline of the molded package, as will be further described.

[0231] Figure 5 A cross-section of another illustrative sensor device 500 is shown, which can be considered as another variant of the sensor device 100 of FIG1. Figure 5 The main difference between device 500 and device 100 in Figure 1 is:

[0232] (i) At least three pressure / stress sensors P1, P2, and P3 are not integrated into the semiconductor substrate 501 in which magnetic sensors M1, M2, and M3 are integrated. Figure 5 In the illustrated embodiment, pressure / stress sensors P1, P2, etc., are discrete sensors located outside the packaged device 507 and mounted on the printed circuit board 506. As can be seen, the packaged sensor device 507 can also be mounted on the printed circuit board 506; (ii) The elastomer 510 is located not only above the substrate 501 containing the magnetic sensor, but also above the pressure sensors P1, P2, etc. Here, the elastomer 510 has a second contact area 512 for receiving the applied external force F, and has one or more first contact areas 511, 511' for guiding or transmitting the force or a portion thereof to the pressure / stress sensors P1, P2, etc.

[0233] exist Figure 5 In the illustrated embodiment, the upper surface of the elastomer 510 is substantially planar, but this is not absolutely necessary for the invention to function, and preferably, the upper surface has a dome shape (not shown).

[0234] exist Figure 5 In the example shown, the semiconductor substrate 501 includes three magnetic sensors (M1 is shown only), which can be arranged on the first virtual circle and spaced apart at multiples of 120°. However, another arrangement of at least three magnetic sensor elements can also be used, such as four magnetic sensors spaced apart at 90°, each of which is a 1D magnetic pixel, a 2D magnetic pixel, or a 3D magnetic pixel.

[0235] exist Figure 5 In the example shown, printed circuit board 506 includes three pressure / stress sensors (P1 and P2 are shown only), which can be arranged on the second virtual circle and spaced apart at multiples of 120°, but another arrangement of at least three pressure / stress sensors, or an arrangement with fewer than three pressure / stress sensors, can also be used.

[0236] exist Figure 5 In a variant (not shown), the molded package of the integrated semiconductor device 507 has, for example, a similar design to... Figure 2 A cavity similar to the one illustrated in the figure (not shown). Optionally, the semiconductor substrate 501 may further include multiple stress sensors integrated in the semiconductor substrate.

[0237] Figure 6 A cross-section of another illustrative sensor device 600 is shown, which can be considered as... Figure 5 A further variant of the sensor device 500, the main difference being that the molded package of the integrated semiconductor device 607 has an opening, for example similar to... Figure 3 Sensor device 300. For Figure 5 All other descriptions and their variations also apply here. Figure 6 One or more optional stress sensors P4 integrated in the semiconductor substrate 601 are also shown. If present, they can provide further pressure (or stress) signals.

[0238] Figure 7A A top view of another illustrative example of a force sensor device 700 is shown, and Figure 7B A cross-sectional view of another illustrative example of a force sensor device 700 is shown.

[0239] The sensor device 700 includes a substrate 706, such as a printed circuit board (PCB). The PCB 706 may have a circular, square, or rectangular shape, but this is not absolutely necessary for the invention to function.

[0240] The sensor device 700 further includes a plurality of magnetic sensors M1 to M4 and a plurality of pressure / stress sensors P1 to P3 mounted on the PCB 706. In the example shown, the PCB 706 includes four magnetic sensors (or magnetic sensor units) M1 to M4 arranged on a first virtual circle having a first radius and spaced apart at multiples of 90°; and includes three pressure sensors P1 to P3 arranged on a second virtual circle having a second radius and spaced apart at multiples of 120°, but other numbers or arrangements of magnetic and pressure sensors may also be used.

[0241] The sensor device 700 further includes an elastomer 710 having a cavity 713. The cavity may be filled with air or a gas (e.g., nitrogen). A magnetic sensor may be positioned inside the cavity 713. A pressure / stress sensor may also be positioned inside the cavity. When a mechanical force is applied to a second surface region of the elastomer, the elastomer can transmit that force to the pressure or stress sensor (e.g., if the elastomer is in mechanical contact with these sensors), or it may cause an increase in the pressure of the air or gas, which can then be sensed by the pressure or stress sensor. Figure 7B In the example, the pressure or stress sensor is in direct contact with the elastomer via one or more first contact areas 711, 711'. The elastomer has a second contact area 712 for receiving the force to be measured.

[0242] The sensor device 700 further includes a magnetic material, such as a permanent magnet 704, magnetic powder, or magnetic particles, positioned in an elastomer 710 such that the magnetic material will displace when an external force F is applied to the second contact surface 712.

[0243] As from Figure 7B As can be understood, when a downward-oriented force F is applied to the second surface 712 of the elastic body 710, the magnet 704 will move in the negative Z direction, but due to the cavity 713, the displacement will be greater than the displacement without the cavity 713. Thus, the cavity 713 helps increase the sensitivity of measurements performed by the magnetic sensor. For relatively small forces, the displacement changes essentially linearly with the magnitude of the force, but above a certain threshold, i.e., for relatively strong forces, the relationship between displacement and the magnitude of the force may become highly nonlinear, and may even be limited to a maximum displacement. From the above, it can be understood that the relationship between the magnitude of the force and the displacement of the magnetic material (e.g., the magnet 704) depends on the orientation of the applied force.

[0244] In some embodiments, only a single force component is measured, namely the force component Fz oriented in a direction perpendicular to the substrate 706. In other embodiments, three force components (Fx, Fy, Fz) are measured. As explained above, a first value of the one or more force components can be calculated based on a signal obtained from a magnetic sensor, and a second value of the one or more force components can be calculated based on a signal obtained from a pressure / stress sensor. As will be further explained, the final value of the force to be determined can then be determined based on the first and second force components, or based on the first set of force component values ​​and the second set of force component values.

[0245] exist Figure 7A and Figure 7B In a variant (not shown), pressure or stress sensors P1 to P3 are also located inside the cavity 713.

[0246] Figure 8Graphs illustrating examples of signals obtainable from magnetic sensors and signals obtainable from pressure / force sensors are shown, illustrating how these signals vary according to an applied force oriented in a specific direction. Only one magnetic signal and only one pressure signal are shown, but the reader will understand that the number of signals can be as many as the number of sensors or sensor units.

[0247] It should be noted that Figure 8 The curves shown are for illustrative purposes only, and the exact curves for a particular device may deviate from the provided figures. Figure 8 The curve shown in the figure is valid, but the following discussion remains relevant. The inventors made the following observations: i) For relatively small forces, the signal obtained from the magnetic sensor is typically more accurate than the signal obtained from the pressure / stress sensor (e.g., in terms of signal-to-noise ratio SNR); therefore, for relatively small forces, the accuracy of one or more first force components is better than the accuracy of one or more second force components. ii) For relatively high forces, the signal obtained from the magnetic sensor is typically highly nonlinear, or may even be clipped or saturated, while the signal obtained from the pressure / stress sensor continues to behave in a highly linear manner over a larger measurement range; therefore, for relatively large forces, the accuracy of one or more second force components is better than that of one or more first force components.

[0248] Based on these observations, several measurement principles were developed for determining one or more force components of an applied force.

[0249] Figure 9 One or more force components (e.g., a set of three force components (Fx, Fy, Fz)) are shown to be derived from signals obtained from a magnetic sensor and / or from signals obtained from a pressure / stress sensor.

[0250] The simplest approach is to use only the signal from the pressure / stress sensor and convert it into a force signal, for example, by matrix multiplication with a matrix having predefined coefficients that can be determined during the calibration process. However, such methods do not provide good accuracy or good resolution for relatively small forces.

[0251] Figure 10A A flowchart is shown for a method 1000a for determining at least three force components (e.g., Fx, Fy, Fz) of a force (e.g., F) using a sensor device as described above, wherein the sensor device is, for example, in Figures 1A to 7B In any one of them, or for example in Figures 14 to 19 In any one of them, or a variant thereof. The method includes the following steps: a) Receive (1002) a first set of signals (e.g., m1, m2, m3) from at least three magnetic sensors (e.g., M1, M2, M3), and determine one or more first force components (e.g., the first force component F1z or the first set of three orthogonal force components F1x, F1y, F1z) based on the first set of signals; b) Receive (1003) a second set of signals (e.g., s1, s2, s3) from at least three pressure or stress sensors (e.g., P1, P2, P3), and determine one or more second force components (e.g., the second force component F2z or the second set of three orthogonal force components F2x, F2y, F2z) based on the second set of signals; c) Determine (1004) one or more force components (e.g., Fz; Fx, Fy, Fz) of the force (e.g., F) based on the one or more first force components (F1x, F1y, F1z) and / or based on the one or more second force components (F2x, F2y, F2z).

[0252] The method may further include step d): perform (1005) a consistency check between the first set of sensor signals and the second set of sensor signals, or between the (one or more) first force components and the (one or more) second force components, or between the first set of force components and the second set of force components, and provide the result of the consistency check (e.g., an error signal).

[0253] Several variants are contemplated, such as: In an embodiment, step a) includes: determining the one or more first force components based on the pairwise differences between the first set of signals (m1, m2, m3). These signals may be less sensitive to external interference fields. In an embodiment, the sensor device includes two magnetic sensors, each configured to measure an in-plane magnetic field component (e.g., Bx), and the magnitude of the force Fz is calculated as a function of the pairwise difference between the two signals, e.g., as a polynomial function or as a linear function.

[0254] In an embodiment, step a) includes: determining a first force component (F1z) oriented in a direction perpendicular to the substrate; and step b) includes: determining a second force component (F2z) oriented in the direction perpendicular to the substrate; and step c) includes: if the first force component (F1z) is less than a first predefined threshold (e.g., if F1z < T1z), then determining the component of the force to be measured (F) as the first force component (F1z); otherwise, determining the component (Fz) of the force to be measured as the second force component (F2z).

[0255] In an embodiment, step a) includes: determining a first force component (F1z) oriented in a direction perpendicular to the substrate; and step b) includes: determining a second force component (F2z) oriented in the direction perpendicular to the substrate; and step c) includes: if the second force component (F2z) is greater than a second predefined threshold (e.g., if F2z > T2z), then the component of the force (F) to be measured is determined as the second force component (F2z); otherwise, the component (Fz) of the force to be measured is determined as the first force component (F1z).

[0256] In an embodiment, step a) includes: determining a first force component (F1z) oriented in a direction perpendicular to the substrate; and step b) includes: determining a second force component (F2z) oriented in the direction perpendicular to the substrate; and step c) includes: determining the force component to be measured as a linear combination of the first force component (F1z) and the second force component (F2z). A weighting factor can be determined based on the first force vector and / or the second force vector, for example, to cause a smooth transition between 100% derived from a magnetic signal for weak forces and 100% derived from a pressure / stress sensor for strong forces. The weighting factor can be a predefined constant value, which can be hard-coded and / or stored in non-volatile memory (e.g., as...). Figures 20 to 22 (As described in the text). The weighting factor can be a temperature-related value.

[0257] In an embodiment, step a) includes: determining a first set of three force components (F1x, F1y, F1z); and step b) includes: determining a second set of three force components (F2x, F2y, F2z); and step c) includes: if each value in the first set of force components is less than a first predefined threshold, then the force to be measured (e.g., force vectors Fx, Fy, Fz) is determined as a first set of force components; and otherwise, the force to be measured is determined as a second set of force components.

[0258] In an embodiment, step a) includes: determining a first set of three force components (F1x, F1y, F1z); and step b) includes: determining a second set of three force components (F2x, F2y, F2z); and step c) includes: if at least one of the values ​​of the first set of force components is less than a first predefined threshold (T1), then the force to be measured (e.g., force vectors Fx, Fy, Fz) is determined as the first set of force components; and otherwise, the force to be measured is determined as the second set of force components.

[0259] In an embodiment, step a) includes: determining a first set of three force components (F1x, F1y, F1z); and step b) includes: determining a second set of three force components (F2x, F2y, F2z); and step c) includes: if each value in the second set of force components is greater than a second predefined threshold (T2), then the force to be measured (e.g., force vectors Fx, Fy, Fz) is determined as a second set of force components; and otherwise, the force to be measured is determined as a first set of force components.

[0260] In an embodiment, step a) includes: determining a first set of three force components (F1x, F1y, F1z); and step b) includes: determining a second set of three force components (F2x, F2y, F2z); and step c) includes: if at least one of the values ​​of the second set of force components is greater than a second predefined threshold (T2), then the force to be measured (e.g., force vectors Fx, Fy, Fz) is determined as a second set of force components; and otherwise, the force to be measured is determined as a first set of force components.

[0261] In an embodiment, step a) includes: determining a first group of three force components (F1x, F1y, F1z); and step b) includes: determining a second group of three force components (F2x, F2y, F2z); and step c) includes: if the corresponding component from the first group (e.g., F1x) is less than a first predefined threshold (T1), then each component (Fx, Fy, Fz) of the force to be measured is determined to be the corresponding component (e.g., F1x) from the first group; and otherwise, each component (Fx, Fy, Fz) of the force to be measured is determined to be the corresponding component (e.g., F2y) from the second group.

[0262] In an embodiment, step a) includes: determining a first group of three force components (F1x, F1y, F1z); and step b) includes: determining a second group of three force components (F2x, F2y, F2z); and step c) includes: if the corresponding component from the second group (e.g., F2x) is greater than a second predefined threshold (T2), then each component (Fx, Fy, Fz) of the force to be measured is determined to be the corresponding component from the second group (e.g., F2x); and otherwise, each component (Fx, Fy, Fz) of the force to be measured is determined to be the corresponding component from the first group (e.g., F1y).

[0263] In an embodiment, step a) includes: determining a first set of three force components (F1x, F1y, F1z), and determining a first amplitude of the first force vector (e.g., as the sum of squares of the values ​​F1x, F1y, F1z, or as the square root of the sum); and step b) includes: determining a second set of three force components (F2x, F2y, F2z), and determining a second amplitude of the second force vector (e.g., by calculating the sum of squares of the values ​​F2x, F2y, F2z, or as the square root of the sum); and step c) includes: if the first amplitude is less than a first predefined threshold (e.g., T3), then the force to be measured is determined as the first force vector; and otherwise, the force to be measured is determined as the second force vector.

[0264] In an embodiment, step a) includes: determining a first set of three force components (F1x, F1y, F1z) and determining a first magnitude of the first force vector (e.g., as the sum of squares of the values ​​F1x, F1y, F1z, or as the square root of the sum); and step b) includes: determining a second set of three force components (F2x, F2y, F2z) ​​and determining a second magnitude of the second force vector (e.g., by calculating the sum of squares of the values ​​F2x, F2y, F2z, or as the square root of the sum); and step c) includes: if the second magnitude is greater than a second predefined threshold (e.g., T4), then the force to be measured is determined as the second force vector; and otherwise, the force to be measured is determined as the first force vector.

[0265] In an embodiment, step a) includes: determining a first set of three force components (F1x, F1y, F1z); and step b) includes: determining a second set of three force components (F2x, F2y, F2z); and step c) includes: determining the force as a set of three force components (Fx, Fy, Fz), wherein each component (e.g., Fx) is calculated as a linear combination, such as the average or weighted average of the corresponding components of the first set (e.g., F1x) and the corresponding components of the second set (e.g., F2x). The weighting factor can be determined based on the magnitude of the first force vector and / or the second force vector, for example, to induce a smooth transition between 100% derived from a magnetic signal for a weak force and 100% derived from a pressure / stress sensor for a strong force. The weighting factor can be a predefined constant value, which can be hard-coded and / or stored in non-volatile memory (e.g., as shown in the image). Figures 20 to 2 (As described in section 3). The weighting factor can be a temperature-related value.

[0266] In an embodiment, step a) includes: determining a first set of three force components (F1x, F1y, F1z); and step b) includes: determining a force component F2z (e.g., oriented perpendicular to the substrate including the pressure / stress sensor); and step c) includes: determining the normal force component (Fz) of the force based on a weighted average of F1z and F2z (e.g., using a predefined constant or a temperature-dependent constant); and determining the shear force component (Fx, Fy, or Fsh) based only on the first force components (F1x, F1y, Fz).

[0267] In an embodiment, the method further includes the steps of: performing a consistency check between a first set of sensor signals and a second set of sensor signals, and / or between a first force component (F1z) and a second force component (F2z), or between a first set of force components (F1x, F1y, F1z) and a second set of force components (F2x, F2y, F2z), and providing the result of the consistency check (e.g., an error signal). The consistency test can be based, for example, on the absolute or relative difference between force vectors F1x and F2x, or F1y and F2y, or F1z and F2z, or between the first amplitude and the second amplitude. If an inconsistency is detected, it may be caused by a magnetic interference field. The inconsistency can be output or transmitted as an error signal.

[0268] In an embodiment, the method further includes the steps of: measuring or estimating the temperature of the elastomer; and step a) includes: taking into account the measured or estimated temperature (e.g., taking into account the temperature-dependent flexibility of the elastomer) to determine the one or more first components (F1x, F1y, F1z).

[0269] Figure 10B A flowchart of method 1000b for determining one or more force components is shown, which can be regarded as Figure 10A Variations of the method include the following steps: i) Provide a sensor arrangement including one or more magnetic sensors (e.g., M1, M2, M3) and one or more pressure or stress sensors (e.g., P1, P2, P3), an elastomer in contact with the pressure sensor, and a magnetic material disposed in the elastomer. a) Receive (1002b) one or more first sensor signals from one or more magnetic sensors, and determine one or more first force components (e.g., F1x, F1y, F1z) based on the one or more first sensor signals. b) Receive (1003b) one or more second sensor signals from one or more pressure / stress sensors, and determine one or more second force components (e.g., F2z) ​​based on the one or more second sensor signals. c) Determine (1004b) one or more force components based on the one or more first force components (e.g., F1x, F1y, F1z) and / or based on the one or more second force components (e.g., F2z).

[0270] After making necessary modifications, a concept was conceived that is consistent with the above (regarding...). Figure 10A The same variants of the method. In all these variants, one or more first force components (F1x, F1y, F1z) can be determined based on the magnetic field component signal or based on the magnetic field difference signal. The latter is less sensitive to external disturbance fields.

[0271] Figure 10C A flowchart of method 1000c for determining one or more force components (Fx, Fy, Fz) is shown. This method can be considered as... Figure 10A Variations of the method or Figure 10C A variant thereof, wherein step i) includes: providing a sensor arrangement comprising having at least three magnetic sensors (e.g., such as...). Figure 15 The figure shows a first substrate (at least three 2D pixels, or at least three 3D pixels, or at least four 2D pixels, or at least four 3D pixels) arranged as illustrated, a second substrate having one or more pressure / stress sensors, an elastomer in contact with one or more pressure sensors, and a magnetic material (e.g., a magnet) disposed within the elastomer. Steps a) to d) are related to... Figure 10B The steps are the same, but take into account the possibility that there may be only one second force component, namely F2z.

[0272] In this method, one or more first force components (F1x, F1y, F1z) can be determined based on the magnetic field component signal or based on the magnetic field difference signal. The latter is less sensitive to external disturbance fields.

[0273] In this method, the Fx and Fy components of the force (i.e., the shear components) can be determined based on the first force component (e.g., by setting Fx=F1x and Fy=F1y), and the Fz component of the force (i.e., the normal component) can be determined in any of the ways described above (especially with...). Figure 10A Related to, for example, as a weighted average of F1z and F2z, or as F1z (e.g., if F1z is less than a predefined threshold), or as F2z (e.g., if F2z is greater than a predefined threshold). In addition, with necessary modifications, a concept related to the above (regarding...) is envisioned. Figure 10A (The same variant of the method).

[0274] Figure 11An illustrative example of a high-level block diagram of a sensor device 1100 is shown, which includes one or more magnetic sensors (e.g., at least three magnetic sensors M1, M2, M3) and one or more pressure / stress sensors, such as multiple pressure / stress sensors P1, P2, P3. The magnetic sensors (one or more) and the pressure sensors can be as shown in Figures 1 to... Figure 7B The arrangement described and illustrated in the document, or as shown in the diagram Figures 14 to 19 The arrangement is illustrated herein, or a variation thereof, but other arrangements within the scope of the claims are also contemplated.

[0275] The sensor device 1100 may further include a temperature sensor TS. The temperature sensor can be configured to measure or estimate the temperature of the elastomer.

[0276] Sensor device 1100 typically also includes bias and readout circuitry (not shown) for biasing the sensor (e.g., with a constant voltage or constant current), and / or for reading signals from the sensor, and for optionally amplifying and digitizing these signals using at least one analog-to-digital converter (ADC), but such circuitry is well known in the art and is not the main focus of this invention, and therefore does not need to be described in detail.

[0277] If the sensor device includes at least one receiving coil and at least one excitation coil, the sensor device 1100 may further include an excitation circuit for exciting at least one excitation coil with an alternating voltage or current signal, and may further include a demodulation circuit for demodulating at least one signal obtained from at least one receiving coil.

[0278] Figure 11 The sensor device 1100 further includes processing circuitry 1130, which preferably includes a programmable processor, such as a microprocessor or a DSP (digital signal processor) with an arithmetic unit, configured to perform the functions described above. Figure 10A or Figure 10B The algorithm described herein, and / or any variant thereof described above. The processing circuitry 1130 may further include or be connected to a non-volatile memory 1131, which may store, for example, one or more thresholds, one or more matrix coefficients, one or more weighting factors, a table having weighting factors that vary according to temperature, one or more coefficients of a polynomial describing a first weighting factor and a second weighting factor that vary according to temperature, and so on.

[0279] Depending on the implementation, the sensor device 1100 can be configured to output one or more of the following: one or more first force components (e.g., F1z), one or more second force components (e.g., F2z), and one or more components of the determined force (e.g., Fz or Fx, Fy, Fz).

[0280] The sensor device 1100 may also optionally provide an error signal, for example when an inconsistency is detected as described in step d) of FIG10, or, for example, in the case of a magnetic interference field being detected.

[0281] The sensor device 1100 can be implemented in a single packaged semiconductor device, such as... Figures 1A to 4 or Figure 15 As illustrated, one or more magnetic sensor elements and one or more pressure / stress sensors are preferably implemented on a single semiconductor substrate, or on two separate semiconductor substrates embedded in a single package (see, for example...). Figure 16 or Figure 17 However, the invention is not limited thereto, and device 1100 may, for example, include a printed circuit board having one or two packaged devices (or “chips”) and optionally having discrete components (see, for example...). Figure 5 , Figure 6 , Figure 7B , Figure 18 , Figure 19 ).

[0282] In one embodiment, sensor device 1100 includes only one magnetic sensor and only one pressure or stress sensor, and is configured to output only a single force component, such as Fz.

[0283] In an embodiment, sensor device 1100 includes at least three or at least four magnetic sensors, but only one pressure or stress sensor, and is configured to output only a single force component, such as Fz.

[0284] Figure 12 An illustrative example of another high-level block diagram of sensor device 1200 is shown, which can be considered as... Figure 11A variant of the sensor device, sensor device 1200, includes a first processing circuit 1230 connected to one or more magnetic sensors (e.g., at least three magnetic sensors M1 to M3), and optionally also connected to a temperature sensor TS, and configured to determine one or more first force components, such as F1z or (F1x, F1y, F1z); and sensor device 1200 includes a second processing circuit 1240 connected to at least one or at least three pressure / stress sensors P1 to P3, and configured to determine one or more second force components, such as F2z or (F2x, F2y, F2z). For the same reasons mentioned above, the bias and readout circuitry is not shown. Although not shown, each of the first and second processing circuits may include or be connected to non-volatile memory.

[0285] exist Figure 12 In the example, the first processing circuit 1230 provides one or more first force components (e.g., F1z or F1x, F1y, F1z) to the second processing circuit 1240, and the second processing circuit provides the result of the force measurement. In other words, in this embodiment, the first processing circuit 1230 is configured to perform step a) of FIG. 10, and the second processing circuit 1240 is configured to perform steps b) and c) of the method of FIG. 10, and optionally also perform step d).

[0286] In a variant (not shown), the second processing circuit 1240 is configured to perform step b) and provide its output to the first processing circuit 1230, and the first processing circuit 1230 is configured to perform steps a) and c), and optionally also perform step d of the method of FIG. 10.

[0287] Figure 13 An illustrative example of yet another high-level block diagram of sensor device 1300 is shown, which can be considered as... Figure 11 or Figure 12 Another variant of the sensor device, wherein a first processing circuit 1330 is configured to perform step a), a second processing circuit 1340 is configured to perform step b), and another processor 1350 (e.g., an ECU) is configured to perform step c) of the method of FIG. 10, may be referred to as a "combiner circuit". In the example shown, each of the first and second processing circuits is connected to the combiner circuit via a separate communication line, but in the variant, both the first and second processing circuits are communicatively connected to the combiner circuit 1350 via a communication bus (not explicitly shown).

[0288] Figure 14A substrate 1401 (e.g., a semiconductor substrate or a printed circuit board) is shown, which includes four magnetic sensors M1, M2, M3, M4 (e.g., four horizontal Hall elements, or four 2D magnetic pixels, or four 3D magnetic pixels) and one or more pressure / stress sensors P1, as well as an elastomer 1410 including a magnet 1404, as may be used in embodiments of the invention. The elastomer may be in direct contact with the substrate 1401 (e.g., similar to...). Figure 3 ), or it can be applied over the packaging substrate (e.g., similar to Figure 1 or Figure 2 Magnet 1404 can be an axially magnetized bipolar cylindrical magnet or a disk magnet. Figure 14 The main purpose is to provide an example of a pressure sensor arrangement with four magnetic sensors and fewer than three pressure sensors.

[0289] Figure 15 A semiconductor substrate 1501 is shown, comprising four magnetic sensors in the form of four 3D magnetic pixels M1, M2, M3, and M4, and a pressure / stress sensor P1. In this example, each 3D magnetic pixel includes an integrated magnetic concentrator (IMC) and four horizontal Hall elements arranged near the periphery of the IMC disk at angular intervals of multiples of 90°. Formulas for determining the magnetic field components and magnetic field difference are provided.

[0290] exist Figure 15 In the example shown, four magnetic sensors are arranged on a virtual circle and spaced at 90° intervals, but they could also be positioned on a virtual ellipse.

[0291] exist Figure 15 In the example shown, the pressure sensor is placed inside the circle, more specifically, at the center of the virtual circle, but this is not absolutely necessary.

[0292] In a variant (not shown), each 3D magnetic pixel includes a horizontal Hall element and two or four vertical Hall elements arranged near the sides of the horizontal Hall element.

[0293] Figure 16 A cross-sectional view of a force sensor device 1600 is shown. The force sensor device 1600 includes a first semiconductor substrate 1601a and a second semiconductor substrate 1601b. The first semiconductor substrate 1601a includes one or more magnetic sensors (e.g., at least three or at least four magnetic sensors M1, M2, M3, M4), and the second semiconductor substrate 1601b includes one or more (e.g., at least three) pressure or stress sensors (only one pressure sensor P1 is shown).

[0294] exist Figure 16In the example, a first semiconductor substrate 1601a is mounted on top of a lead frame, and a second semiconductor substrate is mounted on top of the first semiconductor substrate. The two semiconductor substrates are fixedly positioned relative to each other. The two semiconductor substrates can be wire-bonded to the lead frame using bonding wires. The two substrates and bonding wires (if present) are encapsulated by a molding compound 1602 to form a single package device 1600. The package has an opening for receiving a bottom portion of an elastomer 1610. The elastomer includes a magnet 1604.

[0295] Figure 16 The sensor device 1600 can be considered as Figure 4 A variant of sensor device 400. The main difference is that device 1600 includes two separate semiconductor substrates mounted on top of each other, and the first semiconductor substrate 1601a preferably includes four 3D magnetic pixels positioned on a virtual circle or virtual ellipse, and the second semiconductor substrate 1601b preferably includes fewer than three pressure sensors. Preferably, the orthogonal projection of the pressure sensors(s) onto the first semiconductor substrate is located inside the virtual circle or virtual ellipse. Although not shown, the elastomer 1610 may have a dome-shaped upper surface.

[0296] Figure 17 A cross-sectional view of a force sensor device 1700 is shown, which can be considered as... Figure 17 This is a variant of sensor device 1600. The main difference is that the first semiconductor substrate 1701a (including a magnetic sensor) is mounted to the bottom side of the lead frame, while the second semiconductor substrate 1701b (including at least one pressure sensor) is mounted to the top side of the lead frame. The advantage of this device is that no mechanical stress caused by forces applied to the elastomer is applied to the magnetic sensor. All other contents described for sensor device 1600, with necessary modifications, also apply here.

[0297] Figure 18 A cross-sectional view of a force sensor device 1800 is shown. The force sensor device 1800 includes: a first semiconductor substrate 1801a, the first semiconductor substrate 1801a including at least one magnetic sensor, for example at least three or at least four magnetic sensors (e.g., such as...). Figure 15The diagram illustrates four 3D magnetic pixels arranged as shown. A first semiconductor substrate 1801a is incorporated in a first packaged device (or "chip") 1802a, which is mounted on the bottom side of a third substrate 1806 (e.g., a printed circuit board (PCB)). A second semiconductor substrate 1801b is incorporated in a second packaged device (or "chip") 1802b, which is mounted on the top side of the third substrate 1806, preferably at a position opposite to the first packaged device.

[0298] Preferably, the first substrate includes four 3D magnetic pixels located on a virtual circle or virtual ellipse, and preferably, the second chip 1802b is mounted such that the orthogonal projection of at least one pressure sensor on the first semiconductor substrate 1801a is located inside the virtual circle or virtual ellipse.

[0299] exist Figure 18 In the example shown, the elastomer 1810 is in conjunction with... Figure 6 A similar manner is applied, but this is not absolutely necessary, and in variations, the elastomer 1810 is as illustrated in Figure 1 (on top of the package, not extending beyond the package, and the package must be recessed), or as shown in Figure 1. Figure 2 The diagram shows (on the top of the package, not extending beyond the package, but the package has a recess), or as shown in the image. Figure 3 or Figure 4 As illustrated in the diagram (above the package, which has a recess, and the elastomer is in direct contact with the substrate containing at least one sensor element), an application is made.

[0300] Figure 19 An example of this type of variant is shown.

[0301] Although not explicitly stated, Figures 16 to 19 The elastomer of the device can have a dome-shaped upper surface.

[0302] Figure 20 The experimental measurement results are shown when a normal force is applied to the sensor device described above. More specifically, Figure 20 A graph with many measurement points is shown, illustrating the value of the normal force component F1z derived from the magnetic sensor signal (indicated by the black circle) when the force is increased (i.e., during compression) or decreased (i.e., during release), and the value of the normal force component F2z derived from the pressure or stress sensor signal (indicated by the letter x).

[0303] The inventors surprisingly discovered that the second force component F2z exhibited a slight hysteresis, but the first force component F1z exhibited a significant hysteresis. Even more surprisingly, the hysteresis affected the magnetic sensor signal and the pressure sensor signal in opposite ways. In fact, the value of F1z derived from the magnetic sensor signal at release was greater than the value of F1z at compression, but the value of F2z derived from the pressure / stress sensor signal at release was less than the value of F2z at compression. They surprisingly found that by combining the values ​​of F1z and F2z, the hysteresis of the elastomer could be significantly reduced.

[0304] In an embodiment, the normal force component Fn is determined as a linear combination, or as a weighted average of F1z and F2z, for example, according to the following formula: Fn=w1 F1z+w2 F2z, where w1 and w2 are weighting factors. The weighting factors can be predefined constants or they can depend on temperature. In the latter case, the formula can be written as: Fn = w1(T) F1z+w2(T) F2z.

[0305] Figure 21A The graphs showing numerous measurements of F1z and F2z obtained from experiments in which normal forces of various amplitudes were repeatedly applied and released demonstrate behavior with strong hysteresis.

[0306] Figure 21B A graph of the normal force Fn, which is determined to be the weighted average of the first force component F1z and the second force component F2z using a predefined constant weighting factor, is shown, demonstrating highly linear behavior with significantly reduced hysteresis.

[0307] Figure 22 The diagram illustrates how first sensor signals obtained from at least three magnetic sensors and second sensor signals (one or more) obtained from at least one pressure or stress sensor can be processed.

[0308] In block 2220, the first sensor signal is converted into one or more first force components (e.g., F1z, F1x, F1y) by using known techniques, linear regression techniques, or artificial neural networks, such as based on magnetic field component signals or magnetic field difference signals, optionally further considering temperature signals.

[0309] In block 2221, the second sensor signal(s) are converted into one or more second force components (e.g., F2z) ​​using known techniques (e.g., using a linearization function, a piecewise linear approximation function, or an optional lookup table with interpolation).

[0310] In box 2222, the magnitude of the shear force Fsh, independent of its direction, can be calculated. In the embodiment, the value of Fsh is derived from F1x and F1y, for example, according to the following formula:

[0311] Fsh = sqrt(sqr(F1x)+sqr(sqr(F1y)).

[0312] In box 2223, the value of the normal force component Fn can be calculated as a linear combination of F1z and F2z, for example, as a weighted average of F1z and F2z, for example, according to the following formula: Fn=w1 F1z+w2 F2z, where w1 and w2 are predefined constants; or according to the following formula: Fn=w1(T) F1z+w2(T) F2z, where w1(T) and w2(T) are predefined functions of temperature.

[0313] Finally, while most embodiments are described using magnetic sensing elements (such as Hall sensors) to sense or detect one or more characteristics of a static magnetic field generated by a permanent magnet, the invention is not limited thereto, and the magnetic sensor can also be implemented using one or more detection coils or inductors (e.g., planar coils), for example in a printed circuit board or in an "interconnect stack" of a semiconductor substrate, for sensing one or more characteristics of an alternating magnetic field. In this case, the magnetic material can be a conductive magnetic material, such as a conductive soft magnetic material, or a conductive ferromagnetic material. The conductive magnetic material can be arranged to indirectly generate a secondary magnetic field in response to a primary magnetic field generated by one or more excitation coils, which can also be implemented in the printed circuit board or in the "interconnect stack" of the semiconductor substrate, for example using materials such as EP3961926(A1) (particularly in its...). Figure 8 (a) to Figure 9 (d) or Figure 17 (a) to Figure 19 The coil arrangement described in ( ) is not limited thereto, and does not require at least one component or bonding pad to be positioned within the inner periphery. One or more excitation coils may be positioned near the detection coil. An advantage of embodiments using detection coils and conductive magnetic materials is that permanent magnets are not required.

[0314] Figure label: (Modulus 100): -00 Force sensor device or tactile sensor device -01 Substrate (e.g., semiconductor substrate) -02 (e.g., plastic) molding compounds -03 Leads (or pins) of the lead frame -04 Magnets (e.g., solid magnets or bulk magnets) or magnetic particles -05 Cavity or recess (in molded packaging) -06 Substrate (e.g., PCB) -07 Integrated circuits (e.g., chips, packaged semiconductor devices) -08 Opening -10 elastomer -11 First surface area (in direct or indirect contact with the pressure / stress sensor) -12 Second surface area (used to sense the force to be measured) -13 cavity (e.g., air cavity) Mi magnetic sensor mi signal from the magnetic sensor Pi pressure / stress sensor pi is the signal from the pressure / stress sensor. TS temperature sensor ts is the signal from the temperature sensor.

Claims

1. A sensor device (100; 200; 300; 400; 500; 600; 700; 1100; 1200; 1300; 1400; 1500; 1600; 1700; 1800; 1900) for sensing mechanical force (F), said sensor device comprising: -Substrate (101; 201; 301；401；501；601； 706; 1401; 1501; 1601a; 1701a; 1801a; 1901a), the substrate (101; 201; 301; 401; 501; 601; 706; 1401; 1501; 1601a; 1701a; 1801a; 1901a) includes one or more magnetic sensors (M1, M2, M3) for sensing one or more characteristics of the magnetic field and for providing one or more first sensor signals (m1, m2, m3). - An elastomer (110) having a first surface region (111) fixedly arranged relative to the substrate and a second surface region (112) for receiving the force (F) to be measured. - Magnetic material (104), said magnetic material (104) is used to generate said magnetic field, said magnetic material is arranged or embedded inside said elastomer (110) such that said magnetic material will move when said force (F) is applied to the second surface region (112); - One or more pressure or stress sensors (P1, P2, P3), said one or more pressure or stress sensors (P1, P2, P3) are arranged to directly or indirectly sense the pressure or stress caused by said force (F), and are configured to provide one or more second sensor signals (p1, p2, p3). - Processing circuits (1130; 1230, 1240; 1330, 1340, 1350), the processing circuits (1130; 1230, 1240; 1330, 1340, 1350) being configured to determine one or more force components (Fz; Fx, Fy, Fz) of the force (F) applied to the second surface region (112) based on the one or more first sensor signals (m1, m2, m3) and the one or more second sensor signals (p1, p2, p3); The one or more magnetic sensors and the one or more pressure or stress sensors have fixed positions relative to each other.

2. The sensor device according to claim 1, in, The second surface region (112) has a dome shape.

3. The sensor device according to claim 1 or 2, in, The substrate includes the one or more magnetic sensors and the one or more pressure or stress sensors; Alternatively, the substrate comprising the one or more magnetic sensors may be a first substrate, and the sensor device may further comprise a second substrate, wherein the second substrate comprises the one or more pressure or stress sensors.

4. The sensor device (500; 600) according to any one of claims 1 to 3. in, The substrate including the one or more magnetic sensors is a semiconductor substrate, and the one or more magnetic sensors are embedded in the semiconductor substrate (501; 601), and the semiconductor substrate is incorporated in a package device (507; 607), and the one or more pressure or stress sensors are discrete components surrounding the package device (507; 607).

5. The sensor device according to any one of claims 1 to 3, in, The substrate including the one or more magnetic sensors is a first substrate, and the sensor device further includes a second substrate, which is a semiconductor substrate including the one or more pressure or stress sensors, and the second substrate is incorporated in a package device, and the one or more magnetic sensors are discrete components surrounding the package device.

6. The sensor device (700) according to any one of claims 1 to 3. in, The substrate (706) is a printed circuit board; Furthermore, the one or more magnetic sensors (M1, M2, M3) and the one or more pressure or stress sensors (P1, P2, P3) are discrete components mounted on the printed circuit board.

7. The sensor device (700) according to any one of the preceding claims. in, The elastomer (710a; 710b) has an arched or bridge-shaped shape with a hollow cavity (713) and supporting edges or supporting legs; And one of the following arrangements: i) wherein the one or more magnetic sensors (M1, M2, M3) are arranged below or inside the cavity (713), and the one or more pressure or stress sensors (P1, P2, P3) are arranged below the support edge or support leg. ii) wherein the one or more magnetic sensors (M1, M2, M3) and the one or more pressure or stress sensors (P1, P2, P3) are arranged below or inside the cavity (713).

8. The sensor device (700) according to any one of the preceding claims. in, The substrate includes at least three magnetic sensors (M1, M2, M3) arranged on a first virtual circle. Furthermore, the sensor device includes at least three pressure or stress sensors (P1, P2, P3) arranged on the second virtual circle. Wherein, the second virtual circle is concentric with the first virtual circle, or wherein the orthogonal projection of the second virtual circle onto the substrate including the first virtual circle is concentric with the first virtual circle.

9. The sensor device according to any one of the preceding claims (1500; 1600; 1700; 1800; 1900). in, The substrate includes at least three magnetic sensors (M1, M2, M3) arranged on a virtual circle or virtual ellipse. Furthermore, the orthogonal projections of the one or more pressure or stress sensors onto the substrate are located inside the virtual circle or the virtual ellipse.

10. The sensor device according to any one of the preceding claims, in, The processing circuit is configured to determine one or more first force components based on the one or more first sensor signals obtained from the one or more magnetic sensors (M1, M2, M3); Furthermore, the processing circuitry is configured to determine one or more second force components based on the one or more second sensor signals obtained from the one or more pressure or stress sensors (P1, P2, P3); Furthermore, the processing circuit is further configured to determine one or more force components of the force (F) applied to the second surface (112) based on the one or more first force components and the one or more second force components.

11. The sensor device according to claim 10, Includes at least two magnetic sensors; And among them, The processing circuit is configured to determine the one or more first force components based on one or more pairwise differences between first sensor signals obtained from the at least two magnetic sensors.

12. The sensor device according to claim 10 or 11, It includes four magnetic sensors (M1, M2, M3, M4), each of which can measure three orthogonal magnetic field components (Bx1, By1, Bz1; Bx2, By2, Bz2; Bx3, By3, Bz3; Bx4, By4, Bz4). And among them, The processing circuit is configured to determine at least two magnetic field differences (dBxdx, dBydx, dBzdx, dBxdy, dBydy, dBzdy) between parallel magnetic field components. Furthermore, the processing circuit is configured to determine the one or more first force components (F1x, F1y; F1z) based on the magnetic field difference.

13. The sensor device according to claim 10 or 11, It includes four magnetic sensors (M1, M2, M3, M4), each of which can measure at least two orthogonal magnetic field components (Bx1, Bz1; By2, Bz2; Bx3, Bz3; By4, Bz4). And among them, The processing circuit is configured to determine at least two magnetic field differences (dBxdx, dBzdx, dBydy, dBzdy). Furthermore, the processing circuit is configured to determine the one or more first force components (F1x, F1y, F1z) based on the magnetic field difference.

14. The sensor device according to any one of claims 10 to 13, in, The processing circuit is configured to: if the one or more first force components (F1x, F1y, F1z) are less than a first threshold, determine one or more values ​​of the one or more components (Fx, Fy, Fz) of the force (F) applied to the second surface (112) as the one or more first force components (F1x, F1y, F1z); or otherwise, determine one or more values ​​of the one or more components (Fx, Fy, Fz) of the force (F) applied to the second surface (112) as the one or more second force components (F2x, F2y, F2z). Alternatively, the processing circuit is configured to determine a first amplitude of a first vector corresponding to the one or more first force components (F1x, F1y, F1z), and to test whether the first amplitude is less than a first predefined threshold; and if the test result is true, to determine the one or more force components (Fx, Fy, Fz) of the force to be measured based only on the one or more first force components; and if the test result is false, to determine the one or more force components of the force to be measured based only on the one or more second force components (F2x, F2y, F2z).

15. The sensor device according to any one of claims 10 to 14, in, The sensor device is configured to determine and output three orthogonal force components (Fx, Fy, Fz), which include normal force components (F1z, F2z, Fn) and two shear force components (Fx, Fy). Alternatively, the sensor device may be configured to determine and output two shear force components (Fx, Fy). Alternatively, the sensor device may be configured to determine and output the normal force components (F1z, F2z, Fn) and a single shear force component (Fsh). Alternatively, the sensor device may be configured to determine and output a single shear force component (Fsh).

16. The sensor device according to claim 15, in, The single shear force component (Fsh) or the two shear force components (Fx, Fy) are derived from signals obtained from the one or more magnetic sensors, selectively taking into account the measured temperature value.

17. The sensor device according to claim 15 or 16, in, The normal force component is determined based on signals obtained from both the one or more magnetic sensors and the one or more pressure or stress sensors, selectively taking into account the measured temperature value; Alternatively, the normal force component (Fn) may be determined as a weighted average of the first force component (F1z) and the second force component (F2z) using a predefined weighting factor or a temperature-related weighting factor.

18. The sensor device according to any one of the preceding claims, in, The processing circuit is configured or further configured to perform a consistency test between the one or more first sensor signals and the one or more second sensor signals, or between the one or more first force components (F1x, F1y, F1z) and the one or more second force components (F2x, F2y, F2z); Furthermore, if an inconsistency is detected, the force to be measured is determined solely based on the one or more second force components (F2x, F2y, F2z).

19. A robotic gripper comprising two or more movable elements, each movable element comprising at least one sensor device according to any one of the preceding claims.

20. A method (1000) for determining one or more force components (Fz; Fx, Fy, Fz) of a force (F) using a sensor device according to any one of the preceding claims, the method comprising the steps of: a) Receive (1002) one or more first sensor signals (m1, m2, m3) from the one or more magnetic sensors (M1, M2, M3), and determine one or more first force components (F1z; F1x, F1y, F1z) based on the one or more first sensor signals (m1, m2, m3). b) Receive (1003) one or more second sensor signals (s1, s2, s3) from the one or more pressure or stress sensors (P1, P2, P3), and determine one or more second force components (F2z; F2x, F2y, F2z) ​​based on the one or more second sensor signals (s1, s2, s3); c) Determine (1004) one or more force components (Fz; Fx, Fy, Fz) of the force (F) based on the one or more first force components (F1x, F1y, F1z) and based on the one or more second force components (F2x, F2y, F2z); And optionally, the method further includes the steps of: performing a consistency check between the one or more first sensor signals and the one or more second sensor signals, and / or between the one or more first force components (F1z; F1x, F1y, F1z) and the one or more second force components (F2z; F2x, F2y, F2z); And optionally, the method further includes the step of measuring or estimating the temperature of the elastomer, and wherein step a) includes determining the one or more first force components (F1z; F1x, F1y, F1z) taking into account the measured or estimated temperature.

21. The method according to claim 20, in, Step a) includes: determining the one or more first force components (F1z; F1x, F1y, F1z) based on the pairwise differences between the first set of signals (m1, m2, m3); Alternatively, step a) includes: determining a first force component (F1z) oriented in a direction perpendicular to the substrate; and step b) includes: determining a second force component (F2z) oriented in the direction perpendicular to the substrate; and step c) includes: if the first force component (F1z) is less than a first predefined threshold, then the force (F) to be measured is determined as the first force component (F1z); otherwise, the force (Fz) to be measured is determined as the second force component (F2z). Alternatively, step a) includes: determining a first force component (F1z) oriented in a direction perpendicular to the substrate; and step b) includes: determining a second force component (F2z) oriented in the direction perpendicular to the substrate; and step c) includes: if the second force component (F2z) is greater than a second predefined threshold, then the force to be measured is determined as the second force component (F2z); otherwise, the force to be measured (Fz) is determined as the first force component (F2z). Alternatively, step a) includes: determining a first force component (F1z) oriented in a direction perpendicular to the substrate; and step b) includes: determining a second force component (F2z) oriented in the direction perpendicular to the substrate; and step c) includes: determining the force (F) to be measured as a linear combination of the first force component (F1z) and the second force component (F2z); Alternatively, step a) includes: determining a first set of three force components (F1x, F1y, F1z); and step b) includes: determining a second set of three force components (F2x, F2y, F2z); and step c) includes: if each value in the first set of force components is less than a first predefined threshold (T1), then the force to be measured (e.g., force vectors Fx, Fy, Fz) is determined as the first set of force components; and otherwise, the force to be measured is determined as the second set of force components. Alternatively, step a) includes: determining a first group of three force components (F1x, F1y, F1z); and step b) includes: determining a second group of three force components (F2x, F2y, F2z); and step c) includes: if at least one of the values ​​of the first group of force components is less than a first predefined threshold (T1), then the force to be measured (e.g., force vectors Fx, Fy, Fz) is determined as the first group of force components; and otherwise, the force to be measured is determined as the second group of force components. Alternatively, step a) may include: determining a first set of three force components (F1x, F1y, F1z); and step b) may include: determining a second set of three force components (F2x, F2y, F2z); and step c) may include: if each value in the second set of force components is greater than a second predefined threshold (T2), then the force to be measured (e.g., force vectors Fx, Fy, Fz) is determined to be a force component of the second set; otherwise, the force to be measured is determined to be a force component of the first set. Alternatively, step a) includes: determining a first set of three force components (F1x, F1y, F1z); and step b) includes: determining a second set of three force components (F2x, F2y, F2z); and step c) includes: if at least one of the values ​​of the second set of force components is greater than a second predefined threshold (T2), then the force to be measured (e.g., force vectors Fx, Fy, Fz) is determined as a second set of force components; and otherwise, the force to be measured is determined as a first set of force components. Alternatively, step a) includes: determining a first group of three force components (F1x, F1y, F1z); and step b) includes: determining a second group of three force components (F2x, F2y, F2z); and step c) includes: if the corresponding component from the first group is less than a first predefined threshold (T1), then each component (Fx, Fy, Fz) of the force to be measured is determined to be a corresponding component from the first group; and otherwise, each component (Fx, Fy, Fz) of the force to be measured is determined to be a corresponding component from the second group. Alternatively, step a) may include: determining a first group of three force components (F1x, F1y, F1z); and step b) may include: determining a second group of three force components (F2x, F2y, F2z); and step c) may include: if the corresponding component from the second group is greater than a second predefined threshold (T2), then each component (Fx, Fy, Fz) of the force to be measured is determined to be a corresponding component from the second group; and otherwise, each component (Fx, Fy, Fz) of the force to be measured is determined to be a corresponding component from the first group. Alternatively, step a) includes: determining a first set of three force components (F1x, F1y, F1z) and determining a first amplitude of the first force vector; and step b) includes: determining a second set of three force components (F2x, F2y, F2z) ​​and determining a second amplitude of the second force vector; and step c) includes: if the first amplitude is less than a predefined threshold, then the force to be measured is determined as the first force vector; and otherwise, the force to be measured is determined as the second force vector. Alternatively, step a) may include: determining a first set of three force components (F1x, F1y, F1z) and determining a first amplitude of the first force vector; and step b) may include: determining a second set of three force components (F2x, F2y, F2z) ​​and determining a second amplitude of the second force vector; and step c) may include: if the second amplitude is greater than a predefined threshold, then the force to be measured is determined as the second force vector; and otherwise, the force to be measured is determined as the first force vector. Alternatively, step a) includes: determining a first group of three force components (F1x, F1y, F1z); and step b) includes: determining a second group of three force components (F2x, F2y, F2z); and step c) includes: determining the force as a group of three force components (Fx, Fy, Fz), wherein each component is calculated as a linear combination of corresponding components from the first group and the second group.

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