EP1725837A1 - Magnet sensor arrangement - Google Patents

Magnet sensor arrangement

Info

Publication number
EP1725837A1
EP1725837A1 EP05701536A EP05701536A EP1725837A1 EP 1725837 A1 EP1725837 A1 EP 1725837A1 EP 05701536 A EP05701536 A EP 05701536A EP 05701536 A EP05701536 A EP 05701536A EP 1725837 A1 EP1725837 A1 EP 1725837A1
Authority
EP
European Patent Office
Prior art keywords
gap
magnetic
sensor arrangement
magnetic sensor
sensor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP05701536A
Other languages
German (de)
French (fr)
Inventor
Rasmus Rettig
Christian Bauer
Birgit Vogelgesang
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from DE102004063539A external-priority patent/DE102004063539A1/en
Application filed by Robert Bosch GmbH filed Critical Robert Bosch GmbH
Publication of EP1725837A1 publication Critical patent/EP1725837A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
    • G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
    • G01D5/142—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices
    • G01D5/147—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices influenced by the movement of a third element, the position of Hall device and the source of magnetic field being fixed in respect to each other

Definitions

  • the invention relates to a magnetic sensor arrangement, in particular for sensing the movement of linearly or rotationally moved elements, according to the generic features of the main claim.
  • magnetic field-sensitive sensors are used in many areas in which contactless detection of a movement is desired. This can be both a rotational movement and a linear movement.
  • the movement can be determined directly by the time-changing magnetic field at the sensor location.
  • passive transmitter elements which consist of a soft magnetic material
  • the magnetic field is generated by a working magnet which is firmly connected to the sensor. The sensor measures the change in the magnetic field of the working magnet, which is caused by the movement of the encoder elements.
  • XMR sensors In addition to the Hall technology for magnetic field measurement which is known per se, so-called XMR technologies, ie magnetoresistive measuring principles, are also increasingly being used in the case of passive sensor elements in the motor vehicle sector. It should be noted that XMR sensors, in contrast to Hall sensors, detect the so-called "in-plane" component of the magnetic field in the sensor element. XMR sensors previously used use a working magnet, the field of which must be adjusted so that the offset at the location of the sensitive element is zero, or a so-called back bias field is generated that defines the working point of the sensor.
  • DE 101 28 135 AI describes a concept in which a hard magnetic layer nearby, i.e. is deposited in particular on and / or under a magnetoresistive layer stack.
  • This hard magnetic layer then couples mainly to the magnetosensitive layers through its stray field and thereby generates a so-called bias magnetic field, which acts as a magnetic field offset, so that even with only a slight variation of an external magnetic field superimposed on the internal magnetic field, a well measurable and relatively large one Change in the actual measured value, which is detected as a change in resistance in the layer arrangement, can be achieved.
  • the sensors described above are often designed in a manner known per se for speed detection, for example in motor vehicle technology, in a so-called gradiometer arrangement.
  • the sensor thus only measures the signal of a magnetic pole wheel whose pole pair spacing corresponds approximately to the predefined gradiometer spacing.
  • the gradiometer principle in contrast to the absolutely measuring XMR elements, the sensitivity of the sensors to homogeneous interference fields can be reduced.
  • a comparison of the magnets previously used so that the offset can be eliminated at both locations of the sensor elements of the gradiometer arrangement can no longer be carried out here; Electronic adjustment is possible in principle, but here there is a relatively small signal with a large offset.
  • the magnetic sensor arrangement according to the invention has two sensor elements in a gradiometer arrangement, each of which is assigned to one of two magnetic regions of a gap permanent magnet arranged at a predetermined distance. These areas and the entire gap permanent magnet are advantageously arranged with regard to the dimensions, the gap width and the gap shape, the gap depth and their positions in relation to the sensor elements such that the offset of the output signal of the sensor elements in the gradiometer alignment is minimized.
  • the design of a magnetic circuit that has a working field for one the gradiometer principle, ie generated with a detection of the field gradient sensor is optimized and thus enables offset-free operation of the sensor with variation of the magnetic field by moving encoder elements, in particular ferromagnetic gearwheels.
  • the magnetic circuit was composed of two areas, the fields of which overlap so that the so-called "in-plane" components of the resulting magnetic field, or the working field in the sensitive x-direction in the case of XMR sensors, at the gradiometer positions be reduced so that they vary around the zero position due to the influence of the passive encoder elements. This means that very small signals can be detected without offset.
  • the single-component gap magnet according to the invention is of simpler construction and less expensive to manufacture.
  • the gap of the gap magnet has a wedge-shaped or another curved contour.
  • This gap shape means that the offset optimization in the magnetic circuit is not reduced to the two gradiometer positions, but takes place over a wide area parallel to the surface of the magnet or a flux guide disk. This results in significantly reduced positioning requirements for the gradiometer position of the XMR sensor element with regard to the magnet arrangement.
  • the gap of the gap permanent magnet it is also possible for the gap of the gap permanent magnet to have a rectangular contour.
  • flux guide disks are arranged as homogenizing plates between the sensor elements and the magnetic areas. This homogenizes the field in the plane of the sensor elements and reduces the necessary positioning accuracy of the sensor elements compared to the magnet pair for offset-free operation.
  • the magnetization of the regions is rotated by a predetermined angle ⁇ in each case deviating from its longitudinal direction facing the sensor elements.
  • This premagnetization which is caused by the oblique position of the field, ensures that the sensor elements are located in a magnetic field in which the sensitivity is maximal due to a so-called bias field.
  • an arrangement of the aforementioned homogenizing plates is advantageously possible.
  • the invention can be used particularly advantageously in a magnetic sensor arrangement for detecting the angle of rotation of a wheel as a transmitter element, the wheel, for example as a steel wheel, being provided with teeth on its periphery for influencing the magnetic field in the region of the magnetic sensor arrangement.
  • speed sensors on the wheel or on the crankshaft there are areas of application as speed sensors on the wheel or on the crankshaft, as phase sensors on the camshaft, as speed sensors in the transmission or as other linear travel, angle or proximity sensors in which the magnetic field changes are induced by moving metallic elements , drawing
  • FIG. 1 shows a basic view of a magnetic sensor arrangement with two magnetic areas, which are part of a one-component gap permanent magnet and which are each opposite a magnetoresistive sensor element in a gradiometer arrangement,
  • FIG. 2 shows an arrangement expanded compared to FIG. 1 with flow guide disks as homogenizing plates
  • FIG. 3 shows an exemplary embodiment of a magnetic sensor arrangement with two individual magnets which, as a modification to FIG. 1, have an angled magnetic field
  • FIG. 4 shows an embodiment according to FIG. 3 with homogenizing plates corresponding to FIG. 2,
  • FIG. 5 shows a view of a magnetic sensor arrangement for a sensor wheel provided with steel teeth
  • FIG. 6 shows a diagram of the course of the magnetic field as a function of the position of a tooth or a tooth gap of the sensor wheel according to FIG. 5,
  • FIG. 7 shows a basic view of an exemplary embodiment of the magnetic sensor arrangement with a gap permanent magnet, which, in modification of the previously described described embodiments has a wedge-shaped gap,
  • FIG. 8 shows an arrangement with a flux guide disk that is expanded compared to FIG. 7,
  • FIG. 9 shows an exemplary embodiment in which the wedge-shaped gap is arranged in a compact flow guide disk
  • FIG. 10 shows an exemplary embodiment that has magnetic fields angled away from FIG. 7,
  • FIG. 11 shows an arrangement expanded with respect to FIG. 10 with a flow guide disk
  • FIG. 12 shows an exemplary embodiment with an angled magnetic field, in which the wedge-shaped gap is arranged in a compact flux guide disk
  • Figure 13 is a view of a magnetic sensor arrangement with a wedge-shaped gap for a sensor wheel provided with steel teeth and
  • FIG. 14 shows a diagram of the course of the magnetic field as a function of the position of a tooth or a tooth gap of the sensor wheel according to FIG. 13.
  • FIG. 1 shows a basic view of a magnetic sensor arrangement 1 which has a permanent magnet designed as a split magnet 2.
  • the gap magnet 2 has magnetic on both sides of a gap 3 in the same direction. areas 4 and 5, whose respective magnetic field B is aligned with field lines indicated here in the direction of a sensor 6.
  • the sensor 6 is designed here as an XMR sensor and has two magnetoresistive sensor elements 7 and 8.
  • the sensor elements 7 and 8 are shown in a gradiometer arrangement with the gradiometer distance GM and detect the changes in the respective field gradient, which are caused, for example, by a metallic sensor element, for example a gearwheel shown in FIG. 5, which is guided past the magnetic sensor arrangement 1.
  • the optimal working point of the sensor 6 is set via the distance between the individual magnets 4 and 5, defined by the gap width sa and the gap depth st, and can be adapted to the gradiometer distance GM of the sensor elements 7 and 8. Furthermore, the field line profiles depend on the dimensions h, b and t of the gap magnet 2. For a fixed gradiometer distance GM, e.g. 2.5 mm, can be determined here, for example, by the size, material and arrangement of the gap magnet 2 in such a way that the sensor 6 operates without offset and thus can detect signals that are as small as possible in order in turn to allow the greatest possible distance from a transmitter element.
  • GM e.g. 2.5 mm
  • the magnetic field lines of the magnetic sensor arrangement 1 run such that a small so-called “in-plane” component exists to the outside at the location of the sensor elements 7 and 8.
  • the magnetic field is varied, with the "in-plane” components around the zero position be modulated and thus generate an offset-free signal of the gradiometer arrangement.
  • FIG. 2 An exemplary embodiment can be seen in FIG. 2, in which, in a modification of the exemplary embodiment according to FIG. 1, additional homogenizing plates 9 and 10 are attached between the surfaces of the magnetic regions 4 and 5 and the sensor 6.
  • the field in the plane of the sensor 6 is homogenized with the homogenizing plates 9 and 10 and the necessary positioning accuracy of the sensor 6 with respect to the magnet pair or the areas 4 and 5 is reduced for offset-free operation.
  • the sensor elements 7 and 8 require constant bias. This premagnetization ensures that the sensor elements 7 and 8 are in a magnetic field in which the sensitivity is at a maximum. This so-called bias field is realized in each case with an embodiment shown in FIGS. 3 and 4.
  • this bias field is generated by rotating the magnetization B in the regions
  • FIG. 5 shows a section of a model in which the magnetic sensor arrangement 1 according to the invention, for example according to FIG. 1, is used in connection with a sensor wheel 11 which is provided with teeth 12. -lü ⁇
  • FIG. 7 shows an exemplary embodiment of a gap magnet 20 which is particularly favorable for achieving the advantages according to the invention and which has a wedge-shaped gap 21.
  • FIG. 7 shows the gap magnet 20 and its position relative to the sensor elements 7 and 8 in a gradiometer arrangement in a manner comparable to that in FIG. 1. The optimum working point is set here via the special shape and the dimensions of the wedge-shaped gap 21.
  • a variant of the gap magnet 20, which is provided with a flux guide disk 22 which adapts to the shape of the gap 21, can be seen from FIG.
  • FIG. 9 shows an exemplary embodiment of a magnet 23, in which, instead of a suitably shaped gap 21 in the gap magnet, a specially shaped flux guide disk 24 on the surface of the rectangular magnet 23 for insertion sentence is coming. Due to the properties of the soft magnetic material of the flux guide disk 24, the field in the plane of the sensor elements 7 and 8 is shaped differently than in the case of a pure magnet, the x component (cf. FIG. 7) of the magnetic field being minimized over wide x ranges.
  • the sensor elements 7 and 8 may cause a constant premagnetization.
  • This premagnetization ensures that the sensor elements 7 and 8 are in a magnetic field in which the sensitivity is at a maximum. This can be brought about by a “bias field” according to FIG. 10 and subsequently also according to FIGS. 11 and 12 by rotating the magnetization B in the magnets 20 and 23, respectively.
  • FIG. 10 shows an arrangement without a flow guide disk (see FIG. 7)
  • FIG. 11 shows an arrangement with a flow guide disk 22 (see FIG. 8)
  • FIG. 12 shows an arrangement with a compact flow guide disk 24 with an integrated gap 21 (see FIG. 9).
  • FIG. 13 shows a section of an arrangement that is comparable to FIG. 5 and with which magnetic field simulations for designing the wedge shape of the gap 21 of the flux guide disk 24 can be carried out.
  • the shape of the gap 21 is of great importance, geometries which differ from the rectangular shape being particularly advantageous. As shown in FIGS. 7 to 14, this can be a wedge-shaped gap 21 or any curved shape of the gap.
  • the optimized shape of the gap 21 ensures an offset reduction of the magnetic field B in the gradiometer direction not only at the two positions of the sensor elements 7 and 8 but also over a wide range, so that the required positioning accuracy of the gradiometer in relation to the magnet 20 can be significantly reduced.
  • a simulation result is again shown in FIG. 14 as an example.
  • the x component of the B field (Bx) is plotted here over the gradiometer position x relative to the center of the sensor. It can be seen that the amount of the offset of the magnetic field B is smaller than lmT over a wide range. It can also be seen here that the course of the magnetic field Bx for the two simulated positions of the encoder wheel 11 (tooth 12, course 25) and the gap (course 26)) takes place symmetrically around the zero position, that is to say that the signal of the respective one Sensor element 7,8 is offset-free. The magnetic stroke as the difference between the tooth and gap position, however, remains high.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Transmission And Conversion Of Sensor Element Output (AREA)

Abstract

The invention relates to a magnet sensor arrangement (1) containing sensor elements (7,8) that are sensitive to magnetic fields, the electrical properties of said elements being modifiable according to a magnetic field that can be influenced by a mobile passive transmitter (11). Said magnet sensor arrangement (1) comprises two sensor elements (7,8) in a gradiometer arrangement, that are respectively associated with one of two magnetic regions (4, 5) of a permanent magnet embodied as a gap magnet (2;20;23), said regions being arranged at a pre-determined distance (sa). The magnetic regions (4,5) and the gap magnet (2;20;23) are arranged, in terms of, for example, the wedge shape, dimensions (h,b,t), gap length (sa), gap depth (st), and positions thereof in relation to the sensor elements (7,8), in such a way that the offset of the output signal of the sensor elements (7,8) is minimised in the gradiometer arrangement.

Description

Magnetsensoranordnung The magnetic sensor system
Stand der TechnikState of the art
Die Erfindung betrifft eine Magnetsensoranordnung, insbesondere zur Sensierung der Bewegung von linear oder rota- torisch bewegten Elementen, nach den gattungsgemäßen Merkmalen des Hauptanspruchs .The invention relates to a magnetic sensor arrangement, in particular for sensing the movement of linearly or rotationally moved elements, according to the generic features of the main claim.
Es ist an sich bekannt, dass magnetfeldempfindliche Sensoren in vielen Bereichen Anwendung finden, bei denen eine berührungsfreie Detektierung einer Bewegung gewünscht ist. Dabei kann es sich sowohl um eine Rotationsbewegung als auch eine Linearbewegung handeln. Zu unterscheiden sind hier zwei grundlegend verschiedene Messprinzipien. Zum einen lasst sich durch Anbringen eines oder mehrerer magnetischer Dipole als aktive Elemente auf dem zu detek- tierenden Element die Bewegung direkt durch das sich zeitlich ändernde Magnetfeld am Sensorort bestimmen. Im Gegensatz dazu wird bei passiven Geberelementen, die aus einem weichmagnetischen Material bestehen, das magnetische Feld durch einen Arbeitsmagneten erzeugt, der fest mit dem Sensor verbunden ist. Der Sensor misst die Änderung des Magnetfeldes des Arbeitsmagneten, die durch die Bewegung der Geberelemente hervorgerufen wird. Neben der an sich bekannten Hall-Technologie zur Magnetfeldmessung werden vermehrt auch bei passiven Geberelementen im Kraftfahrzeugbereich alternativ sog. XMR- Technologien, d.h. magnetoresistive Messprinzipien, eingesetzt. Dabei ist zu beachten, dass XMR-Sensoren im Gegensatz zu Hall-Sensoren die sog. "in-plane"-Komponente des Magnetfeldes im Sensorelement detektieren. Bisher übliche XMR-Sensoren verwenden dazu einen Arbeitsmagneten, dessen Feld so abgeglichen werden muss, dass der Offset am Ort des sensitiven Elementes Null ist oder es wird ein sogenanntes Backbias-Feld erzeugt, das den Arbeitspunkt des Sensors definiert.It is known per se that magnetic field-sensitive sensors are used in many areas in which contactless detection of a movement is desired. This can be both a rotational movement and a linear movement. There are two fundamentally different measuring principles. On the one hand, by attaching one or more magnetic dipoles as active elements on the element to be detected, the movement can be determined directly by the time-changing magnetic field at the sensor location. In contrast to this, in the case of passive transmitter elements, which consist of a soft magnetic material, the magnetic field is generated by a working magnet which is firmly connected to the sensor. The sensor measures the change in the magnetic field of the working magnet, which is caused by the movement of the encoder elements. In addition to the Hall technology for magnetic field measurement which is known per se, so-called XMR technologies, ie magnetoresistive measuring principles, are also increasingly being used in the case of passive sensor elements in the motor vehicle sector. It should be noted that XMR sensors, in contrast to Hall sensors, detect the so-called "in-plane" component of the magnetic field in the sensor element. XMR sensors previously used use a working magnet, the field of which must be adjusted so that the offset at the location of the sensitive element is zero, or a so-called back bias field is generated that defines the working point of the sensor.
Beispielsweise ist in der DE 101 28 135 AI ein Konzept beschrieben, bei dem eine hartmagnetische Schicht in der Nähe, d.h. insbesondere auf und/oder unter einem magneto- resistiven Schichtstapel, deponiert wird. Diese hartmagnetische Schicht koppelt dann vorwiegend durch ihr Streufeld an die magnetosensitiven Schichten und erzeugt dabei ein sogenanntes Bias-Magnetfeld, das als Magnetfeld- Offset wirkt, so dass auch bei einer nur schwachen Variation eines dem internen Magnetfeld überlagerten externen Magnetfelds eine gut messbare und relativ große Veränderung des eigentlichen Messwertes, der als Widerstandsänderung in der Schichtanordnung detektiert wird, erreichbar ist.For example, DE 101 28 135 AI describes a concept in which a hard magnetic layer nearby, i.e. is deposited in particular on and / or under a magnetoresistive layer stack. This hard magnetic layer then couples mainly to the magnetosensitive layers through its stray field and thereby generates a so-called bias magnetic field, which acts as a magnetic field offset, so that even with only a slight variation of an external magnetic field superimposed on the internal magnetic field, a well measurable and relatively large one Change in the actual measured value, which is detected as a change in resistance in the layer arrangement, can be achieved.
Die zuvor beschriebenen Sensoren werden in an sich bekannter Weise zur Drehzahlerfassung, beispielsweise in der Kraftfahrzeugtechnik, oft in einer sogenannten Gradiometeranordnung ausgeführt. Das heißt je zwei Zweige einer Wheatstoneschen Messbrücke sind in vorgegebenem Abstand angeordnet, so dass ein homogenes Magnetfeld kein Brückensignal bewirkt. Eine Variation des Magnetfelds im Bereich des vorgegebenen Abstands hingegen erzeugt ein Brückensignal. Damit misst der Sensor nur das Signal eines magnetischen Polrads, dessen Polpaarabstand in etwa dem vorgegebenen Gradiometerabstand entspricht.The sensors described above are often designed in a manner known per se for speed detection, for example in motor vehicle technology, in a so-called gradiometer arrangement. This means that two branches of a Wheatstone measuring bridge are arranged at a predetermined distance, so that a homogeneous magnetic field does not cause a bridge signal. A variation of the magnetic field in the In contrast, the area of the predetermined distance generates a bridge signal. The sensor thus only measures the signal of a magnetic pole wheel whose pole pair spacing corresponds approximately to the predefined gradiometer spacing.
Durch den Einsatz des Gradiometerprinzips in einer magne- toresistiven XMR-Messbrücke lässt sich im Gegensatz zu den absolut messenden XMR-Elementen eine Reduzierung der Empfindlichkeit der Sensoren gegenüber homogenen Störfeldern erreichen. Ein Abgleich der bisher eingesetzten Magnete, so dass an beiden Orten der Sensorelemente der Gradiometeranordnung der Offset eliminiert werden kann, lässt sich hier jedoch nicht mehr durchführen; eine e- lektronischer Abgleich ist zwar prinzipiell möglich, aber hier ist ein relativ kleines Signal auf großem Offset vorhanden .By using the gradiometer principle in a magnetoresistive XMR measuring bridge, in contrast to the absolutely measuring XMR elements, the sensitivity of the sensors to homogeneous interference fields can be reduced. A comparison of the magnets previously used so that the offset can be eliminated at both locations of the sensor elements of the gradiometer arrangement can no longer be carried out here; Electronic adjustment is possible in principle, but here there is a relatively small signal with a large offset.
Vorteile der ErfindungAdvantages of the invention
Bei einer Weiterbildung einer Magnetsens,oranordnung der eingangs angegebenen Art weist die Magnetsensoranordnung erfindungsgemäß zwei Sensorelemente in einer Gradiometeranordnung auf, die jeweils einem von zwei in einem vorgegebenen Abstand angeordneten magnetischen Bereiche eines Spaltpermanentmagneten zugeordnet sind. Diese Bereiche und der gesamte Spaltpermanentmagnet sind in vorteilhafter Weise hinsichtlich der Abmaße, der Spaltbreite sowie der Spaltform, der Spalttiefe und ihrer Positionen zu den Sensorelementen so angeordnet, dass der Offset des Ausgangssignals der Sensorelemente in der Gradiometera- nordung minimiert ist.In a development of a magnetic sensor arrangement of the type specified at the outset, the magnetic sensor arrangement according to the invention has two sensor elements in a gradiometer arrangement, each of which is assigned to one of two magnetic regions of a gap permanent magnet arranged at a predetermined distance. These areas and the entire gap permanent magnet are advantageously arranged with regard to the dimensions, the gap width and the gap shape, the gap depth and their positions in relation to the sensor elements such that the offset of the output signal of the sensor elements in the gradiometer alignment is minimized.
Mit der Erfindung wird somit erreicht, dass die Auslegung eines Magnetkreises, der ein Arbeitsfeld für einen auf dem Gradiometerprinzip, d.h. mit einer Erfassung des Feldgradienten arbeitenden Sensors erzeugt, optimiert ist und somit einen offsetfreien Betrieb des Sensors bei Variation des magnetischen Feldes durch sich bewegende Geberelemente, insbesondere ferromagnetische Zahnräder, ermöglicht. Dazu wurde der Magnetkreis aus zwei Bereichen zusammengesetzt, deren Felder sich so überlagern, dass die sog. "in-plane"-Komponenten des resultierenden magnetischen Feldes, bzw. das Arbeitsfeld in der sensitiven x- Richtung bei XMR-Sensoren, an den Gradiometerpositionen soweit reduziert werden, dass sie durch den Einfluss der passiven Geberelemente um die Nulllage variieren. Somit können sehr kleine Signale offsetfrei detektiert werden.With the invention it is thus achieved that the design of a magnetic circuit that has a working field for one the gradiometer principle, ie generated with a detection of the field gradient sensor is optimized and thus enables offset-free operation of the sensor with variation of the magnetic field by moving encoder elements, in particular ferromagnetic gearwheels. For this purpose, the magnetic circuit was composed of two areas, the fields of which overlap so that the so-called "in-plane" components of the resulting magnetic field, or the working field in the sensitive x-direction in the case of XMR sensors, at the gradiometer positions be reduced so that they vary around the zero position due to the influence of the passive encoder elements. This means that very small signals can be detected without offset.
Dies ist besonders bei sehr empfindlichen magnetoresisti- ven XMR-Sensoren von Vorteil, die möglichst ohne eine Offset-Korrektur einen großen Arbeitsbereich, d.h. sehr große bis sehr kleine Feldstärken, abdecken sollen. Im Vergleich zu Magnetkreisen, die aus mehreren separaten Komponenten bestehen, "'ist der erfindungsgemäße einkompo- nentige Spaltmagnet einfacher aufgebaut und kostengünstiger in der Herstellung.This is particularly advantageous in the case of very sensitive magnetoresistive XMR sensors, which have a large working area, i.e. very large to very small field strengths. In comparison to magnetic circuits, which consist of several separate components, the single-component gap magnet according to the invention is of simpler construction and less expensive to manufacture.
In besonders vorteilhafter Weise weist der Spalt des Spaltmagneten eine keilförmige oder auch eine sonstige kurvenförmige Kontur auf. Diese Spaltform bewirkt, dass bei dem Magnetkreis die Offset inimierung nicht auf die beiden Gradiometerpositionen reduziert ist, sondern über einen weiten Bereich parallel zur Oberfläche des Magneten bzw. einer Flussleitscheibe stattfindet. Somit ergeben sich deutlich reduzierte Positionierungsanforderungen an die Gradiometerposition des XMR-Sensorelements hinsichtlich der Magnetanordnung. Weiterhin ist es jedoch auch möglich, dass der Spalt des Spaltpermanentmagneten eine rechteckige Kontur aufweist.In a particularly advantageous manner, the gap of the gap magnet has a wedge-shaped or another curved contour. This gap shape means that the offset optimization in the magnetic circuit is not reduced to the two gradiometer positions, but takes place over a wide area parallel to the surface of the magnet or a flux guide disk. This results in significantly reduced positioning requirements for the gradiometer position of the XMR sensor element with regard to the magnet arrangement. Furthermore, however, it is also possible for the gap of the gap permanent magnet to have a rectangular contour.
Bei einer vorteilhaften Ausführungsform sind zwischen den Sensorelementen und den magnetischen Bereichen Flussleit- scheiben als Homogenisierungsplatten angeordnet. Damit wird das Feld in der Ebene der Sensorelemente homogenisiert und die notwendige Positioniergenauigkeit der Sensorelemente gegenüber dem Magnetpaar zum offsetfreien Betrieb reduziert.In an advantageous embodiment, flux guide disks are arranged as homogenizing plates between the sensor elements and the magnetic areas. This homogenizes the field in the plane of the sensor elements and reduces the necessary positioning accuracy of the sensor elements compared to the magnet pair for offset-free operation.
Vorteilhaft ist es außerdem, wenn gemäß einer weiteren Ausführungsform die Magnetisierung der Bereiche abweichend von ihrer den Sensorelementen zugewandten Längsrichtung jeweils um einen vorgegebenen Winkel α gedreht ist.It is also advantageous if, according to a further embodiment, the magnetization of the regions is rotated by a predetermined angle α in each case deviating from its longitudinal direction facing the sensor elements.
Durch diese, durch die Schräglage des Feldes bedingte Vormagnetisierung wird erreicht, dass sich die Sensorelemente in einem Magnetfeld befinden, bei dem die Sensiti- vität durch ein sogenanntes Bias-Feld maximal ist. Auch hierbei ist eine Anordnung von den zuvor erwähnten Homogenisierungsplatten in vorteilhafter Weise möglich.This premagnetization, which is caused by the oblique position of the field, ensures that the sensor elements are located in a magnetic field in which the sensitivity is maximal due to a so-called bias field. Here, too, an arrangement of the aforementioned homogenizing plates is advantageously possible.
Besonders vorteilhaft lässt sich die Erfindung bei einer Magnetsensoranordnung zur Erfassung des Drehwinkels eines Rades als Geberelement einsetzen, wobei das Rad, z.B. als Stahlrad, an seinem Umfang mit Zähnen zur Beeinflussung des Magnetfeldes im Bereich der Magnetsensoranordnung versehen ist. Insbesondere bei einer Anwendung in einem Kraftfahrzeug ergeben sich Einsatzgebiete als Drehzahlfühler am Rad oder an der Kurbelwelle, als Phasengeber an der Nockenwelle, als Drehzahlsensor im Getriebe oder als sonstige Linearweg-, Winkel- oder Näherungssensoren, bei denen die Magnetfeldänderungen durch bewegte metallische Elemente induziert werden. ZeichnungThe invention can be used particularly advantageously in a magnetic sensor arrangement for detecting the angle of rotation of a wheel as a transmitter element, the wheel, for example as a steel wheel, being provided with teeth on its periphery for influencing the magnetic field in the region of the magnetic sensor arrangement. In particular in an application in a motor vehicle, there are areas of application as speed sensors on the wheel or on the crankshaft, as phase sensors on the camshaft, as speed sensors in the transmission or as other linear travel, angle or proximity sensors in which the magnetic field changes are induced by moving metallic elements , drawing
Ausführungsbeispiele der Erfindung werden anhand der Zeichnung erläutert. Es zeigen:Embodiments of the invention are explained with reference to the drawing. Show it:
Figur 1 eine Prinzipansicht einer Magnetsensoranordnung mit zwei magnetischen Bereichen, die Bestandteil eins einkomponentigen Spaltpermanentmagneten sind und die jeweils einem magnetoresistiven Sensorelement in einer Gradiometeranordnung gegenüberliegen,FIG. 1 shows a basic view of a magnetic sensor arrangement with two magnetic areas, which are part of a one-component gap permanent magnet and which are each opposite a magnetoresistive sensor element in a gradiometer arrangement,
Figur 2 eine gegenüber der Figur 1 erweiterte Anordnung mit Flussleitscheiben als Homogenisierungsplatten,FIG. 2 shows an arrangement expanded compared to FIG. 1 with flow guide disks as homogenizing plates,
Figur 3 ein Ausführungsbeispiel einer Magnetsensoranordnung mit zwei Einzelmagneten, die in Abwandlung zur Figur 1 ein abgewinkelt liegendes Magnetfeld aufweisen,FIG. 3 shows an exemplary embodiment of a magnetic sensor arrangement with two individual magnets which, as a modification to FIG. 1, have an angled magnetic field,
Figur 4 ein Ausführungsbeispiel nach der Figur 3 mit Homogenisierungsplatten entsprechend der Figur 2,FIG. 4 shows an embodiment according to FIG. 3 with homogenizing plates corresponding to FIG. 2,
Figur 5 eine Ansicht einer Magnetsensoranordnung für ein mit Stahlzähnen versehenes Geberrad,FIG. 5 shows a view of a magnetic sensor arrangement for a sensor wheel provided with steel teeth,
Figur 6 ein Diagramm des Verlaufs des Magnetfeldes in Abhängigkeit von der Position eines Zahnes bzw. einer Zahnlücke des Geberrades nach der Figur 5,FIG. 6 shows a diagram of the course of the magnetic field as a function of the position of a tooth or a tooth gap of the sensor wheel according to FIG. 5,
Figur 7 eine Prinzipansicht eines Ausführungsbei- spiels der Magnetsensoranordnung mit einem Spaltpermanentmagneten, der in Abänderung von den vorher be- schriebenen Ausführungsbeispielen einen keilförmigen Spalt aufweist,FIG. 7 shows a basic view of an exemplary embodiment of the magnetic sensor arrangement with a gap permanent magnet, which, in modification of the previously described described embodiments has a wedge-shaped gap,
Figur 8 eine gegenüber der Figur 7 erweiterte Anordnung mit einer Flussleitscheibe,FIG. 8 shows an arrangement with a flux guide disk that is expanded compared to FIG. 7,
Figur 9 ein Ausführungsbeispiel, bei dem der keilförmige Spalt in einer kompakten Flussleitscheibe angeordnet ist,FIG. 9 shows an exemplary embodiment in which the wedge-shaped gap is arranged in a compact flow guide disk,
Figur 10 ein Ausführungsbeispiel, das in Abwandlung von der Figur 7 abgewinkelt liegende Magnetfelder aufweist,FIG. 10 shows an exemplary embodiment that has magnetic fields angled away from FIG. 7,
Figur 11 eine gegenüber der Figur 10 erweiterte Anordnung mit einer Flussleitscheibe,FIG. 11 shows an arrangement expanded with respect to FIG. 10 with a flow guide disk,
Figur 12 ein Ausführungsbeispiel mit einem abgewinkelten Magnetfeld, bei dem der keilförmige Spalt in einer kompakten Flussleitscheibe angeordnet ist,FIG. 12 shows an exemplary embodiment with an angled magnetic field, in which the wedge-shaped gap is arranged in a compact flux guide disk,
Figur 13 eine Ansicht einer Magnetsensoranordnung mit keilförmigem Spalt für ein mit Stahlzähnen versehenes Geberrad undFigure 13 is a view of a magnetic sensor arrangement with a wedge-shaped gap for a sensor wheel provided with steel teeth and
Figur 14 ein Diagramm des Verlaufs des Magnetfeldes in Abhängigkeit von der Position eines Zahnes bzw. einer Zahnlücke des Geberrades nach der Figur 13.FIG. 14 shows a diagram of the course of the magnetic field as a function of the position of a tooth or a tooth gap of the sensor wheel according to FIG. 13.
Beschreibung der AusführungsbeispieleDescription of the embodiments
In Figur 1 ist eine Prinzipansicht einer Magnetsensoranordnung 1 gezeigt, die einen als Spaltmagnet 2 ausgeführten Permanentmagneten aufweist. Der Spaltmagnet 2 weist beiderseits eines Spaltes 3 in gleicher Richtung magneti- sierte Bereiche 4 und 5 auf, deren jeweiliges magnetisches Feld B mit hier angedeuteten Feldlinien in Richtung auf einen Sensor 6 ausgerichtet ist. Der Sensor 6 ist hier als XMR-Sensor ausgeführt und weist zwei magnetore- sistive Sensorelemente 7 und 8 auf. Die Sensorelemente 7 und 8 sind in einer Gradiometeranordnung mit dem Gradiometerabstand GM dargestellt und erfassen die Änderungen des jeweiligen Feldgradienten, die z.B. durch ein metallisches Geberelement, z.B. ein in Figur 5 gezeigtes Zahnrad, das an der Magnetsensoranordnung 1 vorbeigeführt wird, verursacht wird.FIG. 1 shows a basic view of a magnetic sensor arrangement 1 which has a permanent magnet designed as a split magnet 2. The gap magnet 2 has magnetic on both sides of a gap 3 in the same direction. areas 4 and 5, whose respective magnetic field B is aligned with field lines indicated here in the direction of a sensor 6. The sensor 6 is designed here as an XMR sensor and has two magnetoresistive sensor elements 7 and 8. The sensor elements 7 and 8 are shown in a gradiometer arrangement with the gradiometer distance GM and detect the changes in the respective field gradient, which are caused, for example, by a metallic sensor element, for example a gearwheel shown in FIG. 5, which is guided past the magnetic sensor arrangement 1.
Die Einstellung des optimalen Arbeitspunktes des Sensors 6 erfolgt über den Abstand der Einzelmagnete 4 und 5, definiert durch die Spaltbreite sa und die Spalttiefe st, zueinander und kann an den Gradiometerabstand GM der Sensorelemente 7 und 8 angepasst werden. Weiterhin hängen die Feldlinienverläufe von den Abmaßen h, b und t des Spaltmagneten 2 ab. Für einen festen Gradiometerabstand GM, z.B. 2,5 mm, kann hier beispielsweise durch Größe, Material und Anordnung des Spaltmagneten 2 so bestimmt werden, dass der Sensor 6 offsetfrei arbeitet und somit möglichst kleine Signale detektieren kann um wiederum einen möglichst großen Abstand zu einem Geberelement zu ermöglichen.The optimal working point of the sensor 6 is set via the distance between the individual magnets 4 and 5, defined by the gap width sa and the gap depth st, and can be adapted to the gradiometer distance GM of the sensor elements 7 and 8. Furthermore, the field line profiles depend on the dimensions h, b and t of the gap magnet 2. For a fixed gradiometer distance GM, e.g. 2.5 mm, can be determined here, for example, by the size, material and arrangement of the gap magnet 2 in such a way that the sensor 6 operates without offset and thus can detect signals that are as small as possible in order in turn to allow the greatest possible distance from a transmitter element.
Ohne ein außen vorbeigeführtes Geberelement, z.B. ein Zahnrad, verlaufen die magnetischen Feldlinien der Magnetsensoranordnung 1 so, dass am Ort der Sensorelemente 7 und 8 eine kleine sogenannte "in-plane"-Komponente nach außen existiert. Durch den Einsatz z.B. eines sich bewegenden Zahnrads kommt es zu einer Variation des Magnetfeldes, wobei die "in-plane"-Komponenten um die Nulllage moduliert werden und damit ein offsetfreies Signal der Gradiometeranordnung erzeugen.Without a sensor element guided outside, for example a gearwheel, the magnetic field lines of the magnetic sensor arrangement 1 run such that a small so-called "in-plane" component exists to the outside at the location of the sensor elements 7 and 8. By using a moving gear, for example, the magnetic field is varied, with the "in-plane" components around the zero position be modulated and thus generate an offset-free signal of the gradiometer arrangement.
Aus Figur 2 ist ein Ausführungsbeispiel zu entnehmen, bei dem in Abwandlung zu dem Ausführungsbeispiel nach der Figur 1 zusätzliche Homogenisierungsplatten 9 und 10 zwischen den Oberflächen der magnetischen Bereiche 4 und 5 und dem Sensor 6 angebracht sind. Bei diesem Ausführungs- beispiel wird mit den Homogenisierungsplatten 9 und 10 das Feld in der Ebene des Sensors 6 homogenisiert und damit die notwendige Positioniergenauigkeit des Sensors 6 gegenüber dem Magnetpaar bzw. der Bereiche 4 und 5 zum offsetfreien Betrieb reduziert.An exemplary embodiment can be seen in FIG. 2, in which, in a modification of the exemplary embodiment according to FIG. 1, additional homogenizing plates 9 and 10 are attached between the surfaces of the magnetic regions 4 and 5 and the sensor 6. In this exemplary embodiment, the field in the plane of the sensor 6 is homogenized with the homogenizing plates 9 and 10 and the necessary positioning accuracy of the sensor 6 with respect to the magnet pair or the areas 4 and 5 is reduced for offset-free operation.
Bei einigen Anwendungsbeispielen mit den zuvor beschriebenen magnetoresistiven XMR-Sensorelementen 7 und 8 benötigen die Sensorelemente 7 und 8 eine konstante Vormagnetisierung. Durch diese Vormagnetisierung wird erreicht, dass sich die Sensorelemente 7 und 8 in einem Magnetfeld befinden, bei dem die Sensitivität maximal ist. Realisiert wird dieses sogenannte Bias-Feld jeweils mit einem aus Figur 3 und 4 zu entnehmenden Ausführungsbeispiel.In some application examples with the magnetoresistive XMR sensor elements 7 and 8 described above, the sensor elements 7 and 8 require constant bias. This premagnetization ensures that the sensor elements 7 and 8 are in a magnetic field in which the sensitivity is at a maximum. This so-called bias field is realized in each case with an embodiment shown in FIGS. 3 and 4.
Wie in den Figuren 3 und 4 gezeigt, wird dieses Bias-Feld durch eine Drehung der Magnetisierung B in den BereichenAs shown in FIGS. 3 and 4, this bias field is generated by rotating the magnetization B in the regions
4 und 5 um den Winkel CC realisiert. Dabei lassen sich auch hier, wie zuvor beschrieben, wiederum zwei Aufbauvarianten ohne (Figur 3) und mit einer Justageverbesserung durch Homogenisierungsplatten 9 und 10 (Figur 4) realisieren.4 and 5 realized by the angle CC. Here, as described above, two construction variants without (FIG. 3) and with an adjustment improvement by means of homogenizing plates 9 and 10 (FIG. 4) can also be realized here.
In Figur 5 ist ein Ausschnitt eines Modells dargestellt, bei dem die erfindungsgemäße Magnetsensoranordnung 1, beispielsweise nach der Figur 1, im Zusammenhang mit einem Geberrad 11, das mit Zähnen 12 versehen ist, angewen- -lü¬FIG. 5 shows a section of a model in which the magnetic sensor arrangement 1 according to the invention, for example according to FIG. 1, is used in connection with a sensor wheel 11 which is provided with teeth 12. -lü¬
det wird. Als Beispiel ist in einem Diagramm nach Figur 6 ein Messergebnis dargestellt. Aufgetragen ist hier die sogenannte "in-plane"-Komponente des magnetischen Feldes Bx über der Gradiometerposition relativ zur Mitte des Sensors 6, jeweils für einen Zahn 12 (Verlauf 13) und für eine Zahnlücke (Verlauf 14) .det. As an example, a measurement result is shown in a diagram according to FIG. The so-called "in-plane" component of the magnetic field Bx is plotted here above the gradiometer position relative to the center of the sensor 6, in each case for a tooth 12 (course 13) and for a tooth gap (course 14).
Es ist hier bei einem vorgegeben konstruktiven Versuchsaufbau mit einem Gradiometerabstand GM von 2,5 mm zu erkennen, dass der Verlauf des Magnetfeldes Bx an der Sensorelementposition 1,25 mm für die zwei simulierten Positionen des Geberrades 11 (Zahn 12, Verlauf 13) und der Lücke (Verlauf 14) ) symmetrisch um die Nulllage erfolgt, das heißt, dass das Signal des jeweiligen Sensorelementes 7,8 offsetfrei ist.It can be seen here in a given constructive test setup with a gradiometer distance GM of 2.5 mm that the course of the magnetic field Bx at the sensor element position 1.25 mm for the two simulated positions of the encoder wheel 11 (tooth 12, course 13) and the Gap (course 14)) takes place symmetrically around the zero position, that is to say that the signal of the respective sensor element 7, 8 is offset-free.
In Figur 7 ist ein für die Erreichung der erfindungsgemäßen Vorteile besonders günstiges Ausführungsbeispiel eines Spaltmagneten 20 gezeigt, der einen keilförmigen Spalt 21 aufweist. Die Figur 7 zeigt hier in vergleichbarer Weise wie bei der Figur 1 den Spaltmagneten 20 und dessen Position relativ zu den Sensorelementen 7 und 8 in einer Gradiometeranordnung. Die Einstellung des optimalen Arbeitspunktes erfolgt hier über die spezielle Formgebung und die Abmaße des keilförmigen Spalts 21.FIG. 7 shows an exemplary embodiment of a gap magnet 20 which is particularly favorable for achieving the advantages according to the invention and which has a wedge-shaped gap 21. FIG. 7 shows the gap magnet 20 and its position relative to the sensor elements 7 and 8 in a gradiometer arrangement in a manner comparable to that in FIG. 1. The optimum working point is set here via the special shape and the dimensions of the wedge-shaped gap 21.
Aus Figur 8 ist in Abwandlung zu der Figur 7 eine Variante des Spaltmagneten 20 zu entnehmen, die mit einer Flussleitscheibe 22 versehen ist, die sich der Form des Spaltes 21 anpasst.A variant of the gap magnet 20, which is provided with a flux guide disk 22 which adapts to the shape of the gap 21, can be seen from FIG.
Figur 9 zeigt ein Ausführungsbeispiel eines Magneten 23, bei dem anstelle eines geeignet geformten Spaltes 21 im Spaltmagneten eine speziell geformte Flussleitscheibe 24 auf der Oberfläche des rechteckigen Magneten 23 zum Ein- satz kommt. Durch die Eigenschaften des weichmagnetischen Materials der Flussleitscheibe 24 wird das Feld in der Ebene der Sensorelemente 7 und 8 anders geformt als bei einem reinen Magneten, wobei die x-Komponente (vgl . Figur 7) des Magnetfelds über weite x-Bereiche minimiert wird.FIG. 9 shows an exemplary embodiment of a magnet 23, in which, instead of a suitably shaped gap 21 in the gap magnet, a specially shaped flux guide disk 24 on the surface of the rectangular magnet 23 for insertion sentence is coming. Due to the properties of the soft magnetic material of the flux guide disk 24, the field in the plane of the sensor elements 7 and 8 is shaped differently than in the case of a pure magnet, the x component (cf. FIG. 7) of the magnetic field being minimized over wide x ranges.
Es kann eventuell vorteilhaft sein, wenn bei der Verwendung von sogenannten XMR-Sensoren die Sensorelemente 7 und 8 eine konstante Vormagnetisierung bewirkt wird. Durch diese Vormagnetisierung wird erreicht, dass sich die Sensorelemente 7 und 8 in einem Magnetfeld befinden, bei dem die Sensitivität maximal ist. Dies kann durch ein „Bias-Feld" gemäß Figur 10 und daran anschließend auch gemäß Figur 11 und 12 durch eine Drehung der Magnetisierung B in den Magneten 20 bzw. 23 bewirkt werden.It may be advantageous if, when using so-called XMR sensors, the sensor elements 7 and 8 cause a constant premagnetization. This premagnetization ensures that the sensor elements 7 and 8 are in a magnetic field in which the sensitivity is at a maximum. This can be brought about by a “bias field” according to FIG. 10 and subsequently also according to FIGS. 11 and 12 by rotating the magnetization B in the magnets 20 and 23, respectively.
In der Figur 10 ist eine Anordnung ohne Flussleitscheibe (vgl. Figur 7), in der Figur 11 ist eine Anordnung mit einer Flussleitscheibe 22 (vgl. Figur 8) und in der Figur 12 ist eine Anordnung mit einer kompakten Flussleitscheibe 24 mit eingearbeitetem Spalt 21 (vgl. Figur 9) gezeigt.FIG. 10 shows an arrangement without a flow guide disk (see FIG. 7), FIG. 11 shows an arrangement with a flow guide disk 22 (see FIG. 8), and FIG. 12 shows an arrangement with a compact flow guide disk 24 with an integrated gap 21 (see FIG. 9).
Aus Figur 13 ist ein mit der Figur 5 vergleichbarer Ausschnitt einer Anordnung zu entnehmen, mit dem Magnetfeldsimulationen zur Auslegung der Keilform des Spaltes 21 der Flussleitscheibe 24 durchgeführt werden können.FIG. 13 shows a section of an arrangement that is comparable to FIG. 5 and with which magnetic field simulations for designing the wedge shape of the gap 21 of the flux guide disk 24 can be carried out.
Mit dieser Anordnung können für einen festen Gradiometerabstand, als Beispiel wurden 2,5 mm gewählt, Magnetfeld- simulationen durchgeführt und die Größe, das Material und die Form des Spalts 21 so bestimmt werden, dass der Sensor bei hoher Sensitivität offsetminimiert arbeitet und somit möglichst kleine Signale detektieren kann. Damit erreicht man in einer Anwendung große Abstände zum einem ferromagnetischen Geberrad.With this arrangement, for a fixed gradiometer spacing, 2.5 mm was selected as an example, magnetic field simulations were carried out and the size, the material and the shape of the gap 21 could be determined in such a way that the sensor works offset-minimized with high sensitivity and thus as small as possible Can detect signals. In order to one achieves large distances to a ferromagnetic sensor wheel in one application.
Wie schon in der Beschreibungseinleitung erwähnt, ist die Form des Spaltes 21 von großer Bedeutung, wobei insbesondere von der Rechteckform abweichende Geometrien vorteilhaft sind. Dabei kann es sich, wie anhand der Figuren 7 bis 14 dargestellt, um einen keilförmigen Spalt 21 oder auch um eine beliebige kurvenartige Ausformung des Spalts handeln. Die optimierte Formgebung des Spaltes 21 gewährleistet eine Offsetreduktion des Magnetfeldes B in Gradi- ometerrichtung nicht nur an den zwei Positionen der Sensorelemente 7 und 8 sondern über einen weiten Bereich hinaus, so dass die erforderliche Positioniergenauigkeit des Gradiometers gegenüber dem Magneten 20 deutlich herabgesetzt werden kann.As already mentioned in the introduction to the description, the shape of the gap 21 is of great importance, geometries which differ from the rectangular shape being particularly advantageous. As shown in FIGS. 7 to 14, this can be a wedge-shaped gap 21 or any curved shape of the gap. The optimized shape of the gap 21 ensures an offset reduction of the magnetic field B in the gradiometer direction not only at the two positions of the sensor elements 7 and 8 but also over a wide range, so that the required positioning accuracy of the gradiometer in relation to the magnet 20 can be significantly reduced.
Als Beispiel ist in Figur 14 wiederum ein Simulationsergebnis dargestellt. Aufgetragen ist hier die x-Komponente des B-Feldes (Bx) über der Gradiometerpositipn x relativ zur Sensormitte. Es ist zu erkennen, dass hier der Betrag des Offsets des Magnetfeldes B über einen weiten Bereich kleiner als lmT ist. Es ist auch hier zu erkennen, dass der Verlauf des Magnetfeldes Bx für die zwei simulierten Positionen des Geberrades 11 (Zahn 12, Verlauf 25) und der Lücke (Verlauf 26) ) symmetrisch um die Nulllage erfolgt, das heißt, dass das Signal des jeweiligen Sensorelementes 7,8 offsetfrei ist. Der magnetische Hub als Unterschied zwischen der Position Zahn und Lücke, bleibt jedoch unverändert hoch. A simulation result is again shown in FIG. 14 as an example. The x component of the B field (Bx) is plotted here over the gradiometer position x relative to the center of the sensor. It can be seen that the amount of the offset of the magnetic field B is smaller than lmT over a wide range. It can also be seen here that the course of the magnetic field Bx for the two simulated positions of the encoder wheel 11 (tooth 12, course 25) and the gap (course 26)) takes place symmetrically around the zero position, that is to say that the signal of the respective one Sensor element 7,8 is offset-free. The magnetic stroke as the difference between the tooth and gap position, however, remains high.

Claims

Patentansprüche claims
1) Magnetsensoranordnung mit magnetfeldempfindlichen Sensorelementen (7,8) deren elektrische Eigenschaften in Abhängigkeit von einem Magnetfeld veränderbar sind, das durch ein bewegtes passives Geberelement (11) beeinflussbar ist, dadurch gekennzeichnet, dass die Magnetsensoranordnung (1) zwei Sensorelemente (7,8) in einer Gradiometeranordnung aufweist, die jeweils einem von zwei in einem vorgegebenen Abstand (sa) angeordneten Bereichen (4,5) eines als Spaltmagneten (2) ausgeführten Permanentmagneten zugeordnet sind, wobei die magnetischen Bereiche (4,5) und der Spaltpermanentmagnet (2; 20) hinsichtlich der Abmaße (h,b,t), der Spaltbreite (sa) sowie der Spalttiefe (st) und ihrer Positionen zu den Sensorelementen (7,8) so angeordnet sind, dass der Offset des Ausgangssignals der Sensorelemente (7,8) in der Gradiometeranordung minimiert ist. 2) Magnetsensoranordnung nach Anspruch 1, dadurch gekennzeichnet, dass der Spalt (21) in Richtung der Spalttiefe (st) des Spaltpermanentmagneten (20; 23) eine Kontur mit einer keilförmigen Verengung aufweist.1) Magnetic sensor arrangement with magnetic field-sensitive sensor elements (7, 8) whose electrical properties can be changed as a function of a magnetic field which can be influenced by a moving passive transmitter element (11), characterized in that the magnetic sensor arrangement (1) has two sensor elements (7, 8) in a gradiometer arrangement, each of which is assigned to one of two regions (4, 5), arranged at a predetermined distance (sa), of a permanent magnet designed as a gap magnet (2), the magnetic regions (4, 5) and the gap permanent magnet (2; 20) with respect to the dimensions (h, b, t), the gap width (sa) and the gap depth (st) and their positions in relation to the sensor elements (7,8) are arranged so that the offset of the output signal of the sensor elements (7,8 ) is minimized in the gradiometer arrangement. 2) Magnetic sensor arrangement according to claim 1, characterized in that the gap (21) in the direction of the gap depth (st) of the gap permanent magnet (20; 23) has a contour with a wedge-shaped narrowing.
3) Magnetsensoranordnung nach Anspruch 1, dadurch gekennzeichnet, dass der Spalt des Spaltpermanentmagneten (2) eine rechteckige Kontur aufweist.3) Magnetic sensor arrangement according to claim 1, characterized in that the gap of the gap permanent magnet (2) has a rectangular contour.
4) Magnetsensoranordnung nach Anspruch 1, dadurch gekennzeichnet, dass der Spalt in Richtung der Spalttiefe (st) des Spaltpermanentmagneten eine vorgegebene kurvenförmige Kontur aufweist.4) Magnetic sensor arrangement according to claim 1, characterized in that the gap in the direction of the gap depth (st) of the gap permanent magnet has a predetermined curved contour.
5) Magnetsensoranordnung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass zwischen den Sensorelementen (7,8) und den magnetischen Bereichen (4,5) Flussleitscheiben (9,10) angeordnet sind.5) Magnetic sensor arrangement according to one of the preceding claims, characterized in that between the sensor elements (7,8) and the magnetic areas (4,5) flux guide disks (9,10) are arranged.
6) Magnetsensoranordnung nach Anspruch 5, dadurch gekennzeichnet, dass als Flussleitscheibe (24) ein kompakter Körper angeordnet ist, in den der Spalt (21) eingeformt ist.6) Magnetic sensor arrangement according to claim 5, characterized in that a compact body, into which the gap (21) is formed, is arranged as a flow guide disk (24).
7) Magnetsensoranordnung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die Magnetisierung der Bereiche (4,5) abweichend von ihrer den Sensorelementen (7,8) zugewandten Längsrichtung jeweils um einen vorgegebenen Winkel (α) gedreht ist.7) Magnetic sensor arrangement according to one of the preceding claims, characterized in that the magnetization of the regions (4,5) deviates from their longitudinal direction facing the sensor elements (7,8) in each case by a predetermined angle (α).
8) Magnetsensoranordnung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die Magnetsensoranordnung (1) zur Erfassung des Drehwinkels eines Rades (11) als Geberelement eingesetzt ist, wobei das Rad (11) an seinem Umfang mit Zähnen (12) zur Beeinflussung des Magnetfeldes im Bereich der Magnetsensoranordnung (1) versehen ist.8) Magnetic sensor arrangement according to one of the preceding claims, characterized in that the magnetic sensor arrangement (1) for detecting the angle of rotation of a wheel (11) is used as a transmitter element, the wheel (11) on its circumference with teeth (12) for influencing the magnetic field is provided in the area of the magnetic sensor arrangement (1).
9) Magnetsensoranordnung nach Anspruch 8, dadurch gekennzeichnet, dass das Rad (11) ein Stahlrad ist.9) Magnetic sensor arrangement according to claim 8, characterized in that the wheel (11) is a steel wheel.
10) Magnetsensoranordnung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die Sensorelemente (7,8) magnetoresistive XMR-Sensoren sind. 10) Magnetic sensor arrangement according to one of the preceding claims, characterized in that the sensor elements (7,8) are magnetoresistive XMR sensors.
EP05701536A 2004-03-11 2005-01-18 Magnet sensor arrangement Withdrawn EP1725837A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE102004011810 2004-03-11
DE102004063539A DE102004063539A1 (en) 2004-03-11 2004-12-30 Magnet sensor for use in gradiometer has two magnetic field sensors on plate bridging V-shaped groove in permanent magnet, arranged so that offset of sensor output is minimized
PCT/EP2005/050185 WO2005088259A1 (en) 2004-03-11 2005-01-18 Magnet sensor arrangement

Publications (1)

Publication Number Publication Date
EP1725837A1 true EP1725837A1 (en) 2006-11-29

Family

ID=34960153

Family Applications (1)

Application Number Title Priority Date Filing Date
EP05701536A Withdrawn EP1725837A1 (en) 2004-03-11 2005-01-18 Magnet sensor arrangement

Country Status (3)

Country Link
US (1) US8120351B2 (en)
EP (1) EP1725837A1 (en)
WO (1) WO2005088259A1 (en)

Families Citing this family (87)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080238417A1 (en) * 2007-03-29 2008-10-02 Canon Denshi Kabushiki Kaisha Magnetic substance detection sensor and magnetic substance detecting apparatus
DE102007023815A1 (en) * 2007-05-21 2008-11-27 Sensitec Gmbh Arrangement for scanning a linear or circular scale of ferromagnetic material
US8587297B2 (en) * 2007-12-04 2013-11-19 Infineon Technologies Ag Integrated circuit including sensor having injection molded magnetic material
US8575920B2 (en) 2007-12-05 2013-11-05 Infineon Technologies Ag Magneto-resistive magnetic field sensor
US8058870B2 (en) * 2008-05-30 2011-11-15 Infineon Technologies Ag Methods and systems for magnetic sensing
US8174256B2 (en) 2008-05-30 2012-05-08 Infineon Technologies Ag Methods and systems for magnetic field sensing
US20110187359A1 (en) * 2008-05-30 2011-08-04 Tobias Werth Bias field generation for a magneto sensor
US8610430B2 (en) * 2008-05-30 2013-12-17 Infineon Technologies Ag Bias field generation for a magneto sensor
US8779760B2 (en) 2011-06-09 2014-07-15 Infineon Technologies Ag Angle measurement system including magnet with substantially square face for through-shaft applications
SE536012C2 (en) * 2011-09-14 2013-04-02 Scania Cv Ab Device for measuring the movement of the pump piston roller as it moves against the camshaft in an injection system
US9494660B2 (en) 2012-03-20 2016-11-15 Allegro Microsystems, Llc Integrated circuit package having a split lead frame
US9666788B2 (en) 2012-03-20 2017-05-30 Allegro Microsystems, Llc Integrated circuit package having a split lead frame
US10234513B2 (en) * 2012-03-20 2019-03-19 Allegro Microsystems, Llc Magnetic field sensor integrated circuit with integral ferromagnetic material
US9812588B2 (en) 2012-03-20 2017-11-07 Allegro Microsystems, Llc Magnetic field sensor integrated circuit with integral ferromagnetic material
US9817078B2 (en) 2012-05-10 2017-11-14 Allegro Microsystems Llc Methods and apparatus for magnetic sensor having integrated coil
CN102722932A (en) * 2012-06-19 2012-10-10 兰州大学 Magnetic head of currency detector
EP2713140B1 (en) 2012-09-26 2014-10-08 Nxp B.V. Magnetic field sensor system with a biasing magnet producing a spatially symmetric magnetic field within a plane being defined by magnetoresistive sensor elements
US9411025B2 (en) 2013-04-26 2016-08-09 Allegro Microsystems, Llc Integrated circuit package having a split lead frame and a magnet
US10495699B2 (en) 2013-07-19 2019-12-03 Allegro Microsystems, Llc Methods and apparatus for magnetic sensor having an integrated coil or magnet to detect a non-ferromagnetic target
US10145908B2 (en) 2013-07-19 2018-12-04 Allegro Microsystems, Llc Method and apparatus for magnetic sensor producing a changing magnetic field
US9810519B2 (en) 2013-07-19 2017-11-07 Allegro Microsystems, Llc Arrangements for magnetic field sensors that act as tooth detectors
US9590601B2 (en) 2014-04-07 2017-03-07 Lockheed Martin Corporation Energy efficient controlled magnetic field generator circuit
US9638821B2 (en) 2014-03-20 2017-05-02 Lockheed Martin Corporation Mapping and monitoring of hydraulic fractures using vector magnetometers
US10338162B2 (en) 2016-01-21 2019-07-02 Lockheed Martin Corporation AC vector magnetic anomaly detection with diamond nitrogen vacancies
US9551763B1 (en) 2016-01-21 2017-01-24 Lockheed Martin Corporation Diamond nitrogen vacancy sensor with common RF and magnetic fields generator
US10168393B2 (en) 2014-09-25 2019-01-01 Lockheed Martin Corporation Micro-vacancy center device
US9910104B2 (en) 2015-01-23 2018-03-06 Lockheed Martin Corporation DNV magnetic field detector
US9853837B2 (en) 2014-04-07 2017-12-26 Lockheed Martin Corporation High bit-rate magnetic communication
US9845153B2 (en) 2015-01-28 2017-12-19 Lockheed Martin Corporation In-situ power charging
US10520558B2 (en) 2016-01-21 2019-12-31 Lockheed Martin Corporation Diamond nitrogen vacancy sensor with nitrogen-vacancy center diamond located between dual RF sources
US10088452B2 (en) 2016-01-12 2018-10-02 Lockheed Martin Corporation Method for detecting defects in conductive materials based on differences in magnetic field characteristics measured along the conductive materials
US9557391B2 (en) 2015-01-23 2017-01-31 Lockheed Martin Corporation Apparatus and method for high sensitivity magnetometry measurement and signal processing in a magnetic detection system
US9829545B2 (en) 2015-11-20 2017-11-28 Lockheed Martin Corporation Apparatus and method for hypersensitivity detection of magnetic field
US9910105B2 (en) 2014-03-20 2018-03-06 Lockheed Martin Corporation DNV magnetic field detector
US9817081B2 (en) 2016-01-21 2017-11-14 Lockheed Martin Corporation Magnetometer with light pipe
US9823092B2 (en) 2014-10-31 2017-11-21 Allegro Microsystems, Llc Magnetic field sensor providing a movement detector
WO2016190909A2 (en) 2015-01-28 2016-12-01 Lockheed Martin Corporation Magnetic navigation methods and systems utilizing power grid and communication network
WO2016126436A1 (en) 2015-02-04 2016-08-11 Lockheed Martin Corporation Apparatus and method for recovery of three dimensional magnetic field from a magnetic detection system
GB2550809A (en) 2015-02-04 2017-11-29 Lockheed Corp Apparatus and method for estimating absolute axes' orientations for a magnetic detection system
US9741924B2 (en) * 2015-02-26 2017-08-22 Sii Semiconductor Corporation Magnetic sensor having a recessed die pad
WO2017007514A1 (en) * 2015-07-08 2017-01-12 Lockheed Martin Corporation Precision position encoder/sensor using nitrogen vacancy diamonds
WO2017078766A1 (en) 2015-11-04 2017-05-11 Lockheed Martin Corporation Magnetic band-pass filter
WO2017087013A1 (en) 2015-11-20 2017-05-26 Lockheed Martin Corporation Apparatus and method for closed loop processing for a magnetic detection system
WO2017095454A1 (en) 2015-12-01 2017-06-08 Lockheed Martin Corporation Communication via a magnio
WO2017127081A1 (en) 2016-01-21 2017-07-27 Lockheed Martin Corporation Diamond nitrogen vacancy sensor with circuitry on diamond
WO2017127090A1 (en) 2016-01-21 2017-07-27 Lockheed Martin Corporation Higher magnetic sensitivity through fluorescence manipulation by phonon spectrum control
WO2017127098A1 (en) 2016-01-21 2017-07-27 Lockheed Martin Corporation Diamond nitrogen vacancy sensed ferro-fluid hydrophone
AU2016387314A1 (en) 2016-01-21 2018-09-06 Lockheed Martin Corporation Magnetometer with a light emitting diode
US10371765B2 (en) 2016-07-11 2019-08-06 Lockheed Martin Corporation Geolocation of magnetic sources using vector magnetometer sensors
US10274550B2 (en) 2017-03-24 2019-04-30 Lockheed Martin Corporation High speed sequential cancellation for pulsed mode
US10527746B2 (en) 2016-05-31 2020-01-07 Lockheed Martin Corporation Array of UAVS with magnetometers
US10281550B2 (en) 2016-11-14 2019-05-07 Lockheed Martin Corporation Spin relaxometry based molecular sequencing
US10145910B2 (en) 2017-03-24 2018-12-04 Lockheed Martin Corporation Photodetector circuit saturation mitigation for magneto-optical high intensity pulses
US10338163B2 (en) 2016-07-11 2019-07-02 Lockheed Martin Corporation Multi-frequency excitation schemes for high sensitivity magnetometry measurement with drift error compensation
US20170343621A1 (en) 2016-05-31 2017-11-30 Lockheed Martin Corporation Magneto-optical defect center magnetometer
US10677953B2 (en) 2016-05-31 2020-06-09 Lockheed Martin Corporation Magneto-optical detecting apparatus and methods
US10345395B2 (en) 2016-12-12 2019-07-09 Lockheed Martin Corporation Vector magnetometry localization of subsurface liquids
US10330744B2 (en) 2017-03-24 2019-06-25 Lockheed Martin Corporation Magnetometer with a waveguide
US10359479B2 (en) 2017-02-20 2019-07-23 Lockheed Martin Corporation Efficient thermal drift compensation in DNV vector magnetometry
US10228429B2 (en) 2017-03-24 2019-03-12 Lockheed Martin Corporation Apparatus and method for resonance magneto-optical defect center material pulsed mode referencing
US10317279B2 (en) 2016-05-31 2019-06-11 Lockheed Martin Corporation Optical filtration system for diamond material with nitrogen vacancy centers
US10345396B2 (en) 2016-05-31 2019-07-09 Lockheed Martin Corporation Selected volume continuous illumination magnetometer
US10571530B2 (en) 2016-05-31 2020-02-25 Lockheed Martin Corporation Buoy array of magnetometers
US10408890B2 (en) 2017-03-24 2019-09-10 Lockheed Martin Corporation Pulsed RF methods for optimization of CW measurements
US10260905B2 (en) 2016-06-08 2019-04-16 Allegro Microsystems, Llc Arrangements for magnetic field sensors to cancel offset variations
US10041810B2 (en) 2016-06-08 2018-08-07 Allegro Microsystems, Llc Arrangements for magnetic field sensors that act as movement detectors
US10012518B2 (en) * 2016-06-08 2018-07-03 Allegro Microsystems, Llc Magnetic field sensor for sensing a proximity of an object
US10215590B2 (en) 2016-06-08 2019-02-26 Allegro Microsystems, Llc Magnetic field sensor for sensing a proximity and/or a location of an object
US10371760B2 (en) 2017-03-24 2019-08-06 Lockheed Martin Corporation Standing-wave radio frequency exciter
US10379174B2 (en) 2017-03-24 2019-08-13 Lockheed Martin Corporation Bias magnet array for magnetometer
US10338164B2 (en) 2017-03-24 2019-07-02 Lockheed Martin Corporation Vacancy center material with highly efficient RF excitation
US10459041B2 (en) 2017-03-24 2019-10-29 Lockheed Martin Corporation Magnetic detection system with highly integrated diamond nitrogen vacancy sensor
US10866117B2 (en) 2018-03-01 2020-12-15 Allegro Microsystems, Llc Magnetic field influence during rotation movement of magnetic target
US11255700B2 (en) 2018-08-06 2022-02-22 Allegro Microsystems, Llc Magnetic field sensor
US11079254B2 (en) 2018-08-22 2021-08-03 Christopher James Hahn Magnet rangefinder
US10514476B2 (en) 2018-08-22 2019-12-24 Christopher James Hahn Adjustable sensitivity magnet sensor
WO2020056618A1 (en) * 2018-09-19 2020-03-26 Hamlin Electronics (Suzhou) Ltd. Speed sensor assembly
US11035979B2 (en) 2018-10-08 2021-06-15 Christopher James Hahn Visual biofeedback apparatus
US10823586B2 (en) 2018-12-26 2020-11-03 Allegro Microsystems, Llc Magnetic field sensor having unequally spaced magnetic field sensing elements
US11131567B2 (en) 2019-02-08 2021-09-28 Honda Motor Co., Ltd. Systems and methods for error detection in crankshaft tooth encoding
US11181016B2 (en) 2019-02-08 2021-11-23 Honda Motor Co., Ltd. Systems and methods for a crank sensor having multiple sensors and a magnetic element
US11162444B2 (en) 2019-02-08 2021-11-02 Honda Motor Co., Ltd. Systems and methods for a crank sensor having multiple sensors and a magnetic element
US11199426B2 (en) 2019-02-08 2021-12-14 Honda Motor Co., Ltd. Systems and methods for crankshaft tooth encoding
US10984936B2 (en) 2019-05-17 2021-04-20 Altius Space Machines Inc. Electropermanent magnet array
US11237020B2 (en) 2019-11-14 2022-02-01 Allegro Microsystems, Llc Magnetic field sensor having two rows of magnetic field sensing elements for measuring an angle of rotation of a magnet
US11280637B2 (en) 2019-11-14 2022-03-22 Allegro Microsystems, Llc High performance magnetic angle sensor
US11959820B2 (en) 2021-03-17 2024-04-16 Honda Motor Co., Ltd. Pulser plate balancing

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3426784A1 (en) * 1984-07-20 1986-01-30 Bosch Gmbh Robert MAGNETORESISTIVE SENSOR FOR DELIVERING ELECTRICAL SIGNALS
US4859941A (en) * 1987-03-18 1989-08-22 Sprague Electric Company Proximity selectro with integral magnet, pole-piece plate and pair of magnetic transducers
US5021736A (en) 1989-09-19 1991-06-04 Texas Instruments Incorporated Speed/position sensor calibration method with angular adjustment of a magnetoresistive element
DE4020228A1 (en) * 1990-06-26 1992-01-02 Philips Patentverwaltung ARRANGEMENT FOR DETECTING A MOVING FERROMAGNETIC ELEMENT
US5304926A (en) * 1992-04-08 1994-04-19 Honeywell Inc. Geartooth position sensor with two hall effect elements
JPH10221114A (en) * 1997-02-10 1998-08-21 Mitsubishi Electric Corp Detecting device
US6050242A (en) * 1998-10-21 2000-04-18 Pertronix, Inc. Lobe sensor arrangement for an ignition system
DE10009173A1 (en) * 2000-02-26 2001-09-06 Bosch Gmbh Robert Measuring device for the contactless detection of a ferromagnetic object
DE10128135A1 (en) 2001-06-09 2002-12-19 Bosch Gmbh Robert Magneto-resistive layer arrangement used in a GMR sensor element, an AMR sensor element or a gradiometer comprises a non-magnetic electrically conducting intermediate layer arranged between magnetic layers, and a hard magnetic layer
US6498474B1 (en) * 2001-06-27 2002-12-24 Kelsey-Hayes Company Rotational velocity and direction sensing system
DE10141371A1 (en) 2001-08-23 2003-03-13 Philips Corp Intellectual Pty Magnetoresistive sensor device
DE10158052A1 (en) * 2001-11-27 2003-06-05 Philips Intellectual Property Arrangement for determining the position of a motion sensor element
US20030107366A1 (en) * 2001-12-06 2003-06-12 Busch Nicholas F. Sensor with off-axis magnet calibration
DE10210184A1 (en) * 2002-03-07 2003-09-18 Philips Intellectual Property Magnetic field arrangement for detection of the position and rotational velocity of a rotating element has a coil arrangement for generation of an additional time varying magnetic field to reduce finishing tolerance effects
US7045997B2 (en) * 2002-07-23 2006-05-16 Mitsubishi Denki Kabushiki Kaisha Magnetic detection apparatus

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2005088259A1 *

Also Published As

Publication number Publication date
US8120351B2 (en) 2012-02-21
WO2005088259A1 (en) 2005-09-22
US20080116884A1 (en) 2008-05-22

Similar Documents

Publication Publication Date Title
EP1725837A1 (en) Magnet sensor arrangement
DE102004063539A1 (en) Magnet sensor for use in gradiometer has two magnetic field sensors on plate bridging V-shaped groove in permanent magnet, arranged so that offset of sensor output is minimized
EP1725836A1 (en) Magnetic sensor arrangement
DE102012201348B4 (en) SENSOR
DE112010005280B4 (en) Magnetic position detection device
DE102007025000B3 (en) Magnetic field sensor for monitoring wheel movement in anti-skid system of automobiles, has magnetic field sensor arrangement and magnet body
EP2156143B1 (en) Magnetic field sensor
EP2137498A2 (en) Device for recording the rotational speed of a rotatable part
DE102005038516A1 (en) Device for detecting revolutions of a steering shaft
WO2001063213A1 (en) Measuring device for contactlessly detecting a ferromagnetic object
DE102004017191A1 (en) Device and method for determining a direction of an object
DE102016118376A1 (en) Magnetic angle sensor device and method of operation
DE102009022821A1 (en) Methods and systems for magnetic field detection
EP1527324B1 (en) Magnetoresistive sensor
EP1399750A1 (en) Magneto-resistive layer arrangement and gradiometer with said layer arrangement
DE19647420B4 (en) Device for detecting a magnetic field
DE102007023385A1 (en) Device for non-contact detection of linear or rotational movements
DE19851323B4 (en) Magnetic detector
DE102004063245B4 (en) Magnetic detector
DE102021126775A1 (en) ZERO GAUSS MAGNET FOR DIFFERENTIAL, ROTATION-INDENSITIVE MAGNETIC SPEED SENSORS
DE10250319A1 (en) Device for determining the rotation of a shaft comprises a shaft, a transmitting magnet arranged on the surface of a front side of the shaft or integrated in the region of the surface of the front side, and a GMR sensor element
CH696859A5 (en) Current sensor having a plurality of magnetic field sensors.
DE19955573A1 (en) Position measurement device for absolute or relative angle or path displacements, especially for determining throttle valve position in a combustion engine, is largely dependent only on magnetic field direction, not height or homogeneity
DE10357149A1 (en) The magnetic sensor system
DE19853482B4 (en) magnetic field detector

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20061011

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB HU

DAX Request for extension of the european patent (deleted)
RBV Designated contracting states (corrected)

Designated state(s): DE FR GB HU

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20150801