Sensor device for measuring the position of an element

Abstract

The invention relates to a sensor device for measuring the rotational position of an element rotatable about a rotational axis, comprising a sensor comprising transmitter means (110) for emitting a magnetic field and first receiving means for receiving a magnetic field formed by a first conductor (120) and second receiving means for receiving a magnetic field formed by a second conductor (130), said receiving means being arranged in an annular ring segment having a period P in the circumferential direction about the rotational axis; the first conductor and the second conductor each defining a plurality of loops, the shape of each loop following a basic function f0 in the circumferential direction, the period of the basic function f0 being half the period P, wherein only a part of the loops deviates from the basic function f0 by a correction function fc.

Description

Technical Field

[0001] This invention relates to a sensor device for measuring the rotational position of an element rotatable about a rotation axis. Additionally, this invention relates to a sensor device for measuring the linear position of an element movable along an axis. Background Technology

[0002] Such sensor devices typically include at least one transmitter component for emitting magnetic fields and at least two receiver components for receiving magnetic fields.

[0003] Furthermore, the sensor device is typically formed as a ring segment. The ring segment is a corner sector of the ring, "cutting off" the rest of the ring. More specifically, it is adjacent to the ring with outer and inner radii relative to the axis of rotation, where the outer radius is larger than the inner radius. Moreover, this segment is defined only on the ring by an angle Θ, where angle Θ is less than the sensor's full mechanical resolution of 360°. Such a ring segment saves cost and assembly space. Typically, multiple position elements are defined on the rotor at periodic intervals P, where n is an integer inversely proportional to Θ. Summary of the Invention

[0004] Figure 12 A sensor device 1000 is shown for measuring the rotational position of an element 1200 rotatable about a rotation axis. The sensor includes a transmitter component 1010 for emitting a magnetic field, a first receiver component formed by a first conductor 1020, and a second conductor 1030. The receiver components 1020 and 1030 are arranged within an annular segment for receiving the magnetic field, having a period P about the rotation axis along the circumferential direction C. The first conductor 1020 and the second conductor 1030 each define a plurality of loops, each loop following a fundamental function f0 in the circumferential direction C, with a period half of the period P.

[0005] A drawback of existing sensor devices is their frequent inaccuracy. For example, the annular segments can introduce harmonics of angular error due to the difference in magnetic flux at the ends of the sensor relative to its center. Furthermore, these angular errors can vary across the air gap between the stator carrying the sensor device and the rotor carrying the load.

[0006] Therefore, an object of the present invention is to provide a solution that offers higher accuracy. Another object is to provide a solution that optimizes assembly space, particularly by reducing the area of ​​the annular segment.

[0007] The above objectives are achieved through the independent claims. Advantageous embodiments are achieved through the dependent claims.

[0008] According to an embodiment, the sensor device is used to measure the rotational position of an element rotatable about a rotation axis. According to a first embodiment, a polar coordinate system is used, where each point on the plane is determined by its distance from the pole (i.e., the rotation axis). The distance from the pole is measured in the radial direction, while the angle is measured about the pole in the circumferential direction.

[0009] The sensor device includes a transmitter component for emitting a magnetic field. The transmitter component may include a coil to generate the magnetic field. To save space, the coil may be planar. In particular, the coil may be a helical coil.

[0010] Additionally, according to an embodiment, the sensor device includes a first receiving member formed of a first conductor and a second receiving member formed of a second conductor, the receiving members being arranged within an annular segment for receiving a magnetic field, the annular segment having a period P in the circumferential direction about a rotation axis. An annular segment having a period P means that the annular segment substantially has a period P in the circumferential direction. Specifically, a period P that deviates only from ΔP is intended to be considered an annular segment substantially having a period P. In particular, ΔP is less than half the period P.

[0011] More specifically, each receiving device is arranged around the pole in the circumferential direction within the angular end Θ. Mechanically, the annular segment has a non-zero length P that defines the fundamental period. Electrically, the period P corresponds to 2π or 360 degrees. In this document, the term angular resolution refers to electrical resolution.

[0012] Furthermore, according to the embodiment, the first conductor and the second conductor each define multiple loops. The two conductors enable absolute angle measurement within the loop segment. That is, by comparing two different signals, for example, through division, the absolute position within the loop segment can be determined. This is particularly important for rotational sensors. Specifically, in linear sensors, a single conductor is typically used for relative position measurement. However, even in the case of linear sensors using two conductors, the end portions are not used in the sensor.

[0013] Furthermore, each conductor defines multiple loops. More specifically, as used herein, a loop is a turn of the conductor. Thus, as magnetic field lines pass through the loops, the two receiving elements formed by the individual conductors sense the magnetic field generated by the transmitting element. The element, made of a conductive material, is rotatable about an axis of rotation on a rotor element. When eddy currents are induced in the element, it influences the magnetic field of the transmitting element. In other words, the magnetic field generated by the transmitting element is distributed according to the angular position of the element. Therefore, the element alters the induced voltage in each of the two receiving elements.

[0014] Furthermore, the shape of each loop follows the fundamental function f0 in the circumferential direction, with a period of half the period P. Here, "follows" means that the trace of each loop is shaped by the fundamental function f0.

[0015] The fundamental function f0, with a period of half the period P, indicates that each conductor defines at least two regions, where the two regions are congruent in the circumferential direction when the first region is offset by half the period P. This arrangement allows for the most compact design of the sensor within a ring segment, thus determining angles within 2π. It is noteworthy that following the circumferential direction does not require each loop to extend by half the period P in the circumferential direction. For example, one conductor could form three loops, with the edge loops adjacent to the center loop. The two edge loops together form a region covering half the period P.

[0016] Furthermore, according to the embodiment, only a portion of the loop deviates from the fundamental function f0—the correction function fc. This configuration allows for correction of errors caused by the magnetic field, which differ at the ends of the sensor relative to the center, thus allowing for more accurate measurements.

[0017] As used in this paper, "only a portion of a loop" means that at least one loop, but not all loops, deviates from the shape defined by the fundamental function f0. In other words, at least one loop is shaped by the fundamental function f0.

[0018] As used in this paper, the correction function fc is understood as a function whose magnitude is smaller than that of the fundamental function f0.

[0019] As used herein, "deviation" refers to the fact that the corrected region and the uncorrected region become non-identical when the corrected region is offset by half of the period P in the circumferential direction. The uncorrected region is shaped by a loop following the uncorrected fundamental function f0 in the circumferential direction. The corrected region is shaped by a loop additionally corrected by the correction function fc. In particular, when the corrected region is offset by half of the period P in the circumferential direction, it deviates from the uncorrected region by only a predetermined amount. This predetermined amount allows for the reconstruction of a signal with reduced errors caused by the magnetic field. It is worth noting that the magnetic field differs at the ends of the sensor relative to the center of the sensor.

[0020] Advantageously, the first conductor forms an even number of first loops, and the second conductor forms an odd number of second loops. The even number of first loops allows the end portions of the surrounded region at the circumferential ends to be wedge-shaped, particularly having angled or sharp ends. This configuration avoids errors, thus allowing for more accurate measurement of the signals generated by the first loops. Furthermore, the signals received by the first receiving member and the signals received by the second receiving member are offset in the circumferential direction. This allows for optimized interpolation between the signals received by the first receiving member and the signals received by the second receiving member, thereby allowing for more accurate measurements.

[0021] Even more advantageously, multiple first loops are eye-shaped, and multiple second loops are candy-shaped. The eye-shaped first loops define two convex regions, each expanding and contracting circumferentially about its axis of rotation. The candy-shaped second loops define three loops adjacent circumferentially: a central loop and two edge loops. The central loop defines a convex region, each expanding and contracting circumferentially about its axis of rotation. Similarly, when one edge loop is offset circumferentially by a period P and attached to another edge loop, the two edge loops together form a combined loop. Therefore, the combined loop defines a convex region that expands and contracts circumferentially about its axis of rotation. This configuration allows for optimized use of available sensor space and enables more precise measurements.

[0022] According to an advantageous embodiment, the centroids of the regions defined by the first and second conductors are equal in the circumferential direction. This configuration allows the phase shift term between the values ​​measured by the two receiving components to become zero, thus eliminating the need to account for the phase shift when correcting the measurement. This allows for more accurate measurements. In particular, such errors are difficult to correct later at the user end using software.

[0023] On the other hand, the fundamental function f0 is composed of multiple trigonometric functions. Composition means, for example, combining multiple different trigonometric functions through mathematical operations. Even more advantageously, the correction function fc is derived by changing the amplitude and / or phase of at least one of the trigonometric functions. Therefore, the correction function can be calculated in a particularly simple and accurate manner, enabling more precise measurements.

[0024] According to another aspect, each loop, or at least a portion of each loop, is substantially mirror-symmetric with respect to the circumferential direction. Additionally or alternatively, the first and second conductors, at least a portion of each of the first and second conductors, follow substantially mirror-symmetric trajectories with respect to the radial direction. Such a configuration allows the receiving component to use a symmetrical structure of annular segments, thereby avoiding or at least reducing errors caused by edge effects.

[0025] "Essentially" means that a portion of each loop or a portion of the first and second conductors is symmetrical. In other words, at least a portion of each loop is mirror-symmetrical with respect to the circumferential direction. However, due to the correction function, not all loops or the complete first and second conductors are symmetrical structures.

[0026] According to another advantageous aspect, the plurality of loops defined by the first conductor are offset by a quarter of a period P relative to the loop defined by the second conductor in the circumferential direction. More specifically, the two receiving members have substantially identical shapes (except for a correction factor) that follow half of the period P and are offset from each other by a quarter of the period P in the circumferential direction. This allows for precise determination of the angle.

[0027] According to another advantageous aspect, the adjacent loops defined by the first conductor and the adjacent loops defined by the second conductor are wound in opposite directions. Therefore, voltages with opposite signs are induced in the adjacent loops. In other words, the multiple loops wound in opposite directions allow for a phase / anti-phase arrangement of the loops. Such a configuration allows for more precise determination of angles.

[0028] In another advantageous embodiment, portions of the two conductors defining the loop in the circumferential direction mainly or only include curved portions. This can further improve signal quality. In particular, straight portions may be absent in this region. However, such straight portions may exist in other portions of the conductors. For example, portions of the conductors that define the loop in the radial direction and / or do not surround the loop, e.g., connect adjacent loops, and / or do not constrain / restrict the loop in the circumferential direction, but extend radially toward the loop and / or serve as contacts, e.g., terminating at terminals or solder portions, may include straight portions.

[0029] In a space-saving configuration, the transmitter component surrounds the receiver component. In particular, the transmitter component is shaped as a ring segment.

[0030] To keep the sensor device compact, the transmitter component and / or at least one receiver component can be substantially located in a plane. Preferably, the components are located in the same plane. The plane can be perpendicular to the axis of rotation. Such a plane must be understood as a substantially flat object, with one dimension being much smaller than the other two. Parts of the sensor device can be located, for example, on the front side of the PCB, while other parts can be located on the back side of the PCB. In such an embodiment, the sensor device will still be substantially located in a plane.

[0031] In an easily manufactured embodiment, the transmitter component and / or at least one receiver component may include a conductive path on a PCB. The conductive path may include or be a conductor.

[0032] The magnetic field can be an alternating magnetic field. For example, this can be achieved by applying alternating current to the transmitter component.

[0033] According to the second embodiment, the sensor device is used to measure the linear position of an element that moves linearly along an axis.

[0034] The sensor device includes: a transmitter component for emitting a magnetic field; a first receiver component for receiving a magnetic field formed by a first conductor; and a second receiver component for receiving a magnetic field formed by a second conductor, the receiver components being arranged within a segment having a substantially length L along an axis; the first and second conductors each defining a plurality of loops, each loop having a shape along the axis following a fundamental function f0 and having a length of half L, wherein only a portion of the loop has a shape deviating from the fundamental function f0 by a correction function fc.

[0035] The second embodiment is the same as the first embodiment; however, the concept of a correction function applies to linear sensors.

[0036] According to the second embodiment, the sensor device is used to measure the linear position of an element that can move along a linear axis. According to the second embodiment, a Cartesian coordinate system is used.

[0037] The sensor device includes a transmitter component for emitting a magnetic field. The transmitter component may include a coil to generate the magnetic field. To save space, the coil may be planar. In particular, the coil may be a helical coil.

[0038] Furthermore, according to the second embodiment, the sensor device includes a first receiving member formed of a first conductor and a second receiving member formed of a second conductor, the receiving members being arranged within a segment, preferably rectangular in shape, having a length L along the axis, for receiving a magnetic field. A segment having a length means that the segment substantially has a length L along the axis. Specifically, a length L that deviates only from ΔL is intended to be considered a segment substantially having a length L. In particular, ΔL is less than half the length L.

[0039] Furthermore, according to the second embodiment, the first conductor and the second conductor each define multiple loops. The two conductors enable absolute position measurement within a line segment. That is, the absolute position within the segment can be determined by comparing two different signals, for example, through division. This is particularly important for linear sensors, as they require accurate measurements at the edges. Typically, end portions are not used in linear sensors.

[0040] Furthermore, each conductor defines multiple loops. More specifically, as used herein, a loop is a turn of a wire. Thus, as magnetic field lines pass through a loop, the two receiving elements formed by the free conductors sense the magnetic field generated by the transmitting element. The element, made of a conductive material, is linearly movable along the axis of the receiving element and influences the magnetic field of the transmitting element when eddy currents are induced within it. In other words, the magnetic field generated by the transmitting element is distributed according to the linear position of the element. Therefore, the element alters the induced voltage in each of the two receiving elements.

[0041] Furthermore, the shape of each loop follows the fundamental function f0 along the axis, and its length is a general representation of length L. Here, "follows" means that the trace of each loop is shaped by the fundamental function f0.

[0042] The fundamental function f0, with a length half that of length L, indicates that each conductor defines at least two regions, where the two regions are congruent along the axis when the first region is offset by half the length L along the axis. This arrangement allows for the most compact design of the sensor within a segment. It is worth noting that following the axis does not require each loop to extend half the length L in the axial direction. For example, one conductor could form three loops, with the edge loops adjacent to the center loop. The two edge loops together form a region covering half the length L.

[0043] Furthermore, according to the second embodiment, only a portion of the loop deviates from the fundamental function f0—the correction function fc. This configuration allows for correction of errors caused by the magnetic field, which differ at the ends of the sensor relative to the center, thus allowing for more accurate measurements.

[0044] As used in this paper, "only a portion of a loop" means that at least one loop, but not all loops, deviates from the shape defined by the fundamental function f0. In other words, at least one loop is shaped by the fundamental function f0.

[0045] As used in this paper, the correction function fc is understood as a function whose magnitude is smaller than that of the fundamental function f0.

[0046] As used herein, "deviation" refers to the point where the corrected region and the uncorrected region become non-equivalent when the corrected region is offset by half the length L in the axial direction. The uncorrected region is shaped by a loop along the axis following the uncorrected fundamental function f0. The corrected region is shaped by a loop additionally corrected by the correction function fc. In particular, when the corrected region is offset along the axis to half the length L, it deviates from the uncorrected region by only a predetermined amount. This predetermined amount allows for the reconstruction of a signal with reduced errors caused by the magnetic field. It is worth noting that the magnetic field differs at the ends of the sensor relative to the center of the sensor.

[0047] Advantageously, the first conductor forms an even number of first loops, and the second conductor forms an odd number of second loops. The even number of first loops allows the end portion of the surrounded region at its axial end to be wedge-shaped, particularly with angled or sharp ends. This configuration avoids errors, thus allowing for more accurate measurement of the signals generated by the first loops. Furthermore, the signals received by the first receiving member and the signals received by the second receiving member are offset in the axial direction. This allows for optimized interpolation between the signals received by the first receiving member and the signals received by the second receiving member, thereby allowing for more accurate measurements.

[0048] Even more advantageously, multiple first loops are eye-shaped, and multiple second loops are candy-shaped. The eye-shaped first loops define two convex regions, each expanding and contracting along its axis. The candy-shaped second loops define three loops adjacent in the axial direction: a central loop and two edge loops. The central loop defines a convex region, each expanding and contracting along its axis. Similarly, when one edge loop is offset in the axial direction by a period L and attached to another edge loop, the two edge loops together form a combined loop. Thus, the combined loop defines a convex region that expands and contracts in the axial direction. This configuration allows for optimized use of available sensor space and enables more accurate measurements.

[0049] According to the advantages of the second embodiment, the centroids of the regions defined by the first and second conductors are equal in the axial direction. This configuration allows the phase shift term between the values ​​measured by the two receiving components to become zero, thus eliminating the need to consider the phase shift when correcting the measurement. This allows for more accurate measurements. In particular, such errors are difficult to correct later at the user end using software.

[0050] According to another aspect of the second embodiment, the fundamental function f0 is composed of multiple trigonometric functions. Composition means, for example, combining multiple different trigonometric functions through mathematical operations. Even more advantageously, the correction function fc is derived by changing the amplitude and / or phase of at least one of the trigonometric functions. Therefore, the correction function can be calculated in a particularly simple and accurate manner, allowing for more precise measurements. According to another aspect, each loop or at least a portion of each loop is substantially mirror-symmetric with respect to the axial direction. Additionally or alternatively, the first conductor and the second conductor, at least a portion of each of the first conductor and the second conductor, follow substantially mirror-symmetric trajectories with respect to a direction perpendicular to the axial direction. Such a configuration allows the receiving component to use a symmetrical structure of segments, thereby avoiding or at least reducing errors caused by edge effects.

[0051] "Essentially" means that a portion of each loop or a portion of the first and second conductors is symmetrical. In other words, at least a portion of each loop is mirror-symmetrical with respect to the axial direction. However, due to the correction function, not all loops or the complete first and second conductors are symmetrical structures.

[0052] According to another advantageous aspect of the second embodiment, the plurality of loops defined by the first conductor are offset in the axial direction by a quarter of a length L relative to the loop defined by the second conductor. More specifically, the two receiving members have substantially identical shapes (except for a correction factor) that follow half of the length L and are offset from each other in the axial direction by a quarter of the length L. This allows for precise determination of the axial position.

[0053] According to another advantageous aspect of the second embodiment, the adjacent loops defined by the first conductor and the adjacent loops defined by the second conductor are wound in opposite directions. Therefore, voltages with opposite signs are induced in the adjacent loops. In other words, the multiple loops wound in opposite directions allow for a phase / anti-phase arrangement of the loops. Such a configuration allows for more precise location determination.

[0054] In another advantageous aspect of the second embodiment, portions of the two conductors defining the loop in the axial direction primarily or solely comprise bent portions. This can further improve signal quality. In particular, straight portions may be absent in this region. However, such straight portions may exist in other portions of the conductors. For example, portions of the conductor that define the loop in a direction perpendicular to the axis and / or do not surround the loop, e.g., connect adjacent loops, and / or do not constrain / restrict the loop in the axial direction, but instead extend into the loop and / or serve as contacts in a direction perpendicular to the axis, e.g., terminating at a terminal or solder portion, may include straight portions.

[0055] In the space-saving configuration of the second embodiment, the transmitter component surrounds the receiver component. In particular, the transmitter component is a segment with a rectangular shape.

[0056] To keep the sensor device compact, the transmitter component and / or at least one receiver component can be substantially located in a plane. Preferably, the components are located in the same plane. The plane can be perpendicular to the surface of the target element. Such a plane must be understood as a substantially flat object, with one dimension being much smaller than the other two. Parts of the sensor device can be located, for example, on the front side of the PCB, while other parts can be located on the back side of the PCB. In such an embodiment, the sensor device will still be substantially located in a plane.

[0057] In the ease of manufacture aspect of the second embodiment, the transmitter component and / or at least one receiver component may include a conductive path on a PCB. The conductive path may include or be a conductor.

[0058] The magnetic field can be an alternating magnetic field. For example, this can be achieved by applying alternating current to the transmitter component.

[0059] The invention will now be described in detail by way of example using advantageous embodiments and with reference to the accompanying drawings. The described embodiments are merely possible positions in which the various features described above may be provided independently of each other or may be omitted. Attached Figure Description

[0060] The invention will now be described by way of example with reference to the accompanying drawings, in which:

[0061] Figure 1This is a schematic diagram of the components of a sensor device according to the first embodiment, which is used to measure the rotational position of an element that can rotate about a rotation axis;

[0062] Figure 2 It is a schematic diagram of a loop that follows the fundamental function f0 in the circumferential direction;

[0063] Figure 3 This is a schematic diagram of the first receiving component and the coil;

[0064] Figure 4 This is a schematic diagram of the first receiving component, which contains a rotatable element arranged at the rotor.

[0065] Figure 5 This is a schematic diagram of the second receiving component and the coil;

[0066] Figure 6 According to another embodiment Figure 1 A schematic diagram of a portion of the sensor device;

[0067] Figure 7 According to another embodiment Figure 1 A schematic diagram of a portion of the sensor device;

[0068] Figure 8 According to another embodiment Figure 1 A schematic diagram of a portion of the sensor device;

[0069] Figure 9 According to another embodiment Figure 1 A schematic diagram of the sensor device;

[0070] Figure 10 This is the circuit board of the first part of the sensor;

[0071] Figure 11 This is the circuit board of the second part of the sensor;

[0072] Figure 12 This is a schematic diagram of the components of a sensor device used to measure the rotational position of an element that can rotate about a rotation axis. Detailed Implementation

[0073] The invention will now be explained in more detail with reference to the accompanying drawings. (Refer to...) Figure 1 This is a schematic diagram of a sensor device assembly 100 for measuring the rotational position of an element 200 that can rotate about a rotation axis. The rotatable element can be a shaft, such as the shaft of a car engine.

[0074] A conductive element 200 is attached to a rotatable element, causing it to rotate with the element. Not shown in the figure, the element consists of n components, where n is an integer. Each component is connected to a shaft and protrudes laterally from the shaft perpendicular to the axis of rotation.

[0075] The sensor device includes a transmitter component 110 for emitting a magnetic field, a first receiver component formed by a first conductor 120, and a second receiver component formed by a second conductor 130.

[0076] The element 200 forming the wing interferes with the magnetic field generated by the transmitter component 110, causing the receiving elements 120 and 130 to receive different magnetic field strengths depending on the position and thus rotational position of the element 200. Therefore, the rotational position of the element 200 can be deduced from the signals received by the receiving components 120 and 130.

[0077] in addition, Figure 1 An auxiliary line 130' is shown, which defines the shape of the second conductor 130 following the fundamental function f0 and not deviating from the shape of the fundamental function f0 by the correction function fc. It is noteworthy that the auxiliary line 130' and... Figure 12 The second conductor 1030 shown is equivalent. The first conductor 120 defines two loops around regions 122 and 124. The second conductor 130 defines three loops around regions 132, 134, and 136. The first conductor 120 and the second conductor cover a ring segment with a period P in the circumferential direction C.

[0078] For reference Figure 2 As described in detail, the shapes of the four loops surrounding regions 122, 124, 132, and 136 follow a fundamental function f0 with a period of P / 2 in the circumferential direction C. According to... Figure 1 In the illustrated embodiment, the shape of a loop around region 134 deviates from the fundamental function f0 – correction function fc. Notably, auxiliary line 130' defines a loop that surrounds region 134' and follows the fundamental function f0 with P / 2 in the circumferential direction C.

[0079] First, refer to Figure 2 The basic function f0 is described in more detail. According to one embodiment, the basic function f0 consists of a first function f1 and a second function f2. The first function f1 and the second function f2 are substantially mirror-symmetric to each other with respect to the circumferential direction of the cylinder. According to one embodiment, the first function f1 can be represented by equation (1), and the second function f2 can be represented by equation (2):

[0080] (1) f1=HA0+HA1*cos(α)+HA2*cos(2α)+HA3*cos(3α)

[0081] (2) f2=HA0-HA1*cos(α)-HA2*cos(2α)-HA3*cos(3α),

[0082] The coefficients HA0 to HA3 describe the magnitudes of the trigonometric functions, and α is the independent variable of the trigonometric functions. Advantageously, the coefficients can be chosen such that the endpoints of the first function f1 and the endpoints of the second function f2 converge.

[0083] in addition, Figure 3 An example of a first receiving member formed by a first conductor 120 defining two loops is shown, the shape of each loop following a fundamental function f0 in the circumferential direction. More specifically, the first conductor 120 defines two surrounding regions 122 and 124. In particular, the first conductor 120 depicts the shape of two adjacent eyes, referred to herein as eye-shaped loops. It is noteworthy that each loop follows a fundamental function f0 in the circumferential direction. Figure 2 The shape defined in the code.

[0084] According to one embodiment, the loops are wound in opposite directions. More specifically, at the intersection 126, the first conductor 120 is not short-circuited. In other words, in the region of intersection 126, the first conductor 120 is at different levels to avoid current. For example, as... Figure 10 and Figure 11 As shown, the first portion 120A of the first conductor can be located on the front side of the PCB, while the second portion 120B of the first conductor can be located on the back side of the PCB.

[0085] like Figure 3 As shown, when the surrounded region 122 is offset by half the period P in the circumferential direction C, the surrounded regions 122 and 124 are congruent. In other words, the two surrounded regions are shaped in the circumferential direction by the same fundamental function f0 with period P.

[0086] In addition, Figure 3 The center indicates the transmitter component 110 surrounding the first receiving component. When a magnetic field is emitted from the transmitter component 110, an induced voltage is generated. Arrows 123 and 125 indicate the winding direction of the coil. For illustrative purposes, the conductors in the figure are closed, but in reality, one side of the loop is open and connected to the chip that measures these signals.

[0087] Since the two adjacent loops formed by the first conductor 120 are wound in opposite directions, and the regions 122 and 124 defined by the loop conductors are equal, the measured net voltage is 0V.

[0088] Apart from Figure 3 , Figure 4 An element 200 is shown, which is opposite to the region 122 surrounded by the loop of conductor 120.

[0089] Due to the magnetic field generated by transmitter component 110, eddy currents are induced in element 200. Therefore, the magnetic field decreases within region 122. Consequently, as indicated by arrow 127, a low voltage is induced in the loop surrounding region 122, and the measured voltage is not equal to 0V. The rotational position of the element can be derived from the amount of the induced voltage.

[0090] in addition, Figure 5 An example of a first receiving member formed by a second conductor 130 defining three loops is shown, the shape of each loop following a fundamental function f0 in the circumferential direction. More specifically, the second conductor 130 defines three surrounded regions 132, 134, and 136. In particular, the second conductor 130 depicts a candy shape, referred to herein as a candy-shaped loop. It is noteworthy that the central region 134... Figure 2 The surrounded region shown is the same. Furthermore, by offsetting edge region 132 in the circumferential direction with a period P and combining region 132 with edge region 136, it is possible to derive the same... Figure 2 The combined regions shown are the same as the areas surrounded by the same area.

[0091] According to one embodiment, adjacent loops are wound in opposite directions. In other words, at intersections 138 and 139, the second conductor 130 is not short-circuited. In other words, at the regions of intersections 138 and 139, the second conductor 130 is positioned at different levels to avoid current. For example, as... Figure 10 and Figure 11 As shown, the first portion 130A of the second conductor can be located on the front side of the PCB, while the second portion 130B of the second conductor can be located on the back side of the PCB.

[0092] like Figure 5 As shown, when the surrounded region 132 is offset by half of the period P in the circumferential direction C, the surrounded region 132 is congruent to a portion of the surrounded region 134. Similarly, when a portion of the surrounded region 136 is offset by half of the period P in the circumferential direction C, the surrounded region 134 is congruent to a portion of the surrounded region 134.

[0093] According to the present invention, only a portion of the loop deviates from the fundamental function f0. Figure 1 In the embodiment shown, the loop around region 134 deviates from the fundamental function f0, which is determined by... Figure 1 The auxiliary line 130' is shown in the diagram.

[0094] More in detail, such as Figure 1As shown, transmitter component 110 follows the shape of annular segments. Specifically, transmitter component 110 includes radial portions 112 and 114 and segment portions 116 and 118. Due to the radial portions 112 and 114, the magnetic field is not constant in the circumferential direction. More specifically, the magnetic field is non-uniform in the circumferential direction. Therefore, the angular resolution deteriorates near the radial portions 112 and 114. A correction function fc is used to compensate for these errors.

[0095] according to Figure 1 In the embodiment shown, the correction function fc is derived by changing the coefficient HA1 in equations (1) and (2) of the central loop of the second conductor 130 (i.e., the loop surrounding region 134). Therefore, the error caused by the radial portions 112 and 114 is compensated by changing the region 134 surrounded by the central loop formed by the second conductor 130.

[0096] Figures 6 to 9 Alternative embodiments are shown. Specifically, in Figures 6 to 8 In the middle, the shape of the loop defined by the second conductor 130 surrounding the edge region 136 deviates from the shape of the loop that follows the basic function (indicated by the auxiliary line 130'). Figure 6 The correction function fc in the embodiment shown is derived by changing the coefficient HA1 in equations (1) and (2). Figure 7 The correction function fc in the embodiment shown is derived by changing the coefficients HA1 and HA3 in equations (1) and (2). Figure 8 The correction function fc in the illustrated embodiment is derived by adding a phase shift term to the independent variable in equations (1) and (2). A combination of phase shift and coefficient variation can be used to determine the correction function fc.

[0097] In addition, Figure 9 In this case, the shape of the loop defined by the first conductor 120 surrounding region 124 deviates from the shape of the loop that follows the basic function (indicated by the auxiliary line 120').

[0098] It is worth noting that, Figures 6 to 9 Only a portion of the sensor device is shown. According to an advantageous embodiment, the first and second conductors follow substantially mirror-symmetrical trajectories with respect to a radial axis 150, which points in the radial direction.

[0099] It must be understood that, for illustrative purposes, alternative embodiments are described separately. Combinations of these embodiments are possible. For example, a loop defined by a first conductor and two loops defined by a second conductor are corrected, while a third loop of the second conductor (e.g., a central loop) is shaped by a fundamental function f0. It is worth noting that the fundamental function f0 is not limited to the four terms discussed in equations (1) and (2).

[0100] Advantageously, element 200 is an annular segment having a length P / 2 in the circumferential direction. Element 200 is opposite to sensor 100. The outer radius 210 of the element is greater than the radius of segment 116, and the inner radius 220 of the element is smaller than the radius of segment 118.

[0101] Furthermore, the correction function can be adapted to compensate for errors in the magnetic field caused by varying air gaps. For example, the distance between the element 200 opposite the sensor 100, i.e., the air gap, depends on the temperature of the sensor assembly. For instance, if a car is in motion, the sensor assembly will heat up. During sensor operation, the correction function fc can compensate for the temperature effects that cause changes in the air gap. Therefore, the angular resolution is optimized.

[0102] Figure 10 The circuit board showing the first part of the sensor is shown. Figure 11 The circuit diagram of the second part of the sensor is shown.

[0103] According to one embodiment, a first portion 110A of the transmitter component is located on the front side of the printed circuit board (PCB), and a second portion 110B is located on the back side of the PCB. In such an embodiment, the sensor device is still substantially located in a plane.

[0104] according to Figure 10 and Figure 11 In the illustrated embodiment, the transmitter component includes a conductive path forming a coil, particularly a helical coil on an arc-shaped carrier, implemented as a PCB. When current passes through the transmitter component, a magnetic field is generated, which is subsequently disturbed by the rotating component and received by the receiving component. Depending on whether the current in the transmitter component flows in one direction or another (e.g., clockwise or counterclockwise in the transmitter component), the magnetic field points in one direction or another.

[0105] according to Figure 10 and Figure 11 In another aspect of the illustrated embodiment, the first receiving member includes a first portion 120A of a first conductor located on the front side, and a second portion 120B of the first conductor located on the back side of the PCB. The second receiving member includes a first portion 130A of the first conductor located on the front side, and a second portion 130B of the first conductor located on the rear side of the PCB.

[0106] According to another embodiment not shown in the figures, the receiving component can be manufactured separately from the coil. In particular, at least one of the receiving components can be manufactured on a PCB, and the transmitter can be manufactured on a different PCB.

[0107] The second embodiment is not shown in the figure. However, the described concepts can be applied to linear sensors.

[0108] List of reference numerals

[0109] Figure label description

[0110] 100, 1000 components

[0111] 110, 1010 transmitter components

[0112] The first part of the 110A transmitter component

[0113] The second part of the 110B transmitter component

[0114] 112, 114 Radial portions

[0115] Sections 116 and 118

[0116] 120, 1020 First conductor

[0117] 120A First part of the first conductor

[0118] 120B First conductor, second part

[0119] 120' Auxiliary Line

[0120] 122, 124 The enclosed area defined by the loop

[0121] 130, 1030 Second conductor

[0122] 130A Second Conductor First Part

[0123] 130B Second conductor, second part

[0124] 132, 133, 136 The enclosed region defined by the loop.

[0125] 130' Auxiliary Line

[0126] 134' The enclosed area defined by auxiliary lines

[0127] 150 Mirror Axis

[0128] C. Circumferential direction

[0129] R radial direction

[0130] P cycle

[0131] P / 2 half-cycle

[0132] P / 4 quarter cycle

Claims

1. A sensor device for measuring the rotational position of an element rotatable about a rotation axis, the sensor device comprising: Transmitter component (110) for transmitting a magnetic field; A first receiving member, formed by a first conductor (120) and receiving the magnetic field, and The second receiving member, formed by the second conductor (130) and receiving the magnetic field, is arranged in an annular segment having a period P along the circumferential direction (C) about the axis of rotation. The first conductor and the second conductor each define multiple loops, the shape of each loop following a fundamental function f0 in the circumferential direction. The period of the fundamental function f0 is half of the period P, and the fundamental function is composed of multiple trigonometric functions. The shape of a portion of the loop of only one of the first conductors and the second conductor deviates from the fundamental function f0 - correction function fc, while the other loops of the first conductor and the second conductor follow the fundamental function.

2. The sensor device according to claim 1, wherein the number of the first conductors forms an even number of first loops, and the number of the second conductors forms an odd number of second loops.

3. The sensor device according to claim 2, wherein the plurality of first loops are eye-shaped and the plurality of second loops are candy-shaped.

4. The sensor device of claim 3, wherein the centroids of the regions defined by the first conductor and the second conductor are substantially equal in the circumferential direction.

5. The sensor device of claim 4, wherein the correction function fc is derived by changing the amplitude and / or phase of at least one of the trigonometric functions.

6. The sensor device of claim 5, wherein each loop is substantially mirror-symmetric with respect to the circumferential direction.

7. The sensor device of claim 6, wherein the first conductor and the second conductor follow a trajectory that is substantially mirror-symmetric with respect to the radial direction (R).

8. The sensor device according to claim 7, wherein, The plurality of loops defined by the first conductor are offset relative to the loop defined by the second conductor along the circumferential direction by one-quarter of the period P.

9. The sensor device according to claim 8, wherein, The adjacent loop defined by the first conductor and the adjacent loop defined by the second conductor are wound in opposite directions.

10. The sensor device of claim 9, wherein the portions of the two conductors defining the loop in the circumferential direction primarily comprise bent portions.

11. The sensor device of claim 10, wherein the transmitter component comprises a coil.

12. The sensor device of claim 11, wherein the transmitter component surrounds the first receiver component and the second receiver component.

13. The sensor device of claim 12, wherein the transmitter component and / or at least one of the first receiver component or the second receiver component is substantially located in a plane, and / or at least one of the first receiver component or the second receiver component includes a conductive path on a PCB.

14. A sensor device for measuring the linear position of an element moving linearly along an axis, the sensor device comprising: Transmitter components used to emit magnetic fields; A first receiving member, formed by a first conductor, receives the magnetic field. The second receiving member is formed by the second conductor and receives the magnetic field. The first receiving member and the second receiving member are arranged in a segment having a length L along the axis. The basic function is composed of a plurality of trigonometric functions. The first conductor and the second conductor each define a plurality of loops, the shape of each loop following a fundamental function f0 along the axis, the length of which is half the length L. The shape of a portion of the loop of only one of the first conductors and the second conductor deviates from the fundamental function f0 - correction function fc, while the other loops of the first conductor and the second conductor follow the fundamental function.

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