WO2002095334A1 - Method for contactless, linear position measurement - Google Patents

Method for contactless, linear position measurement Download PDF

Info

Publication number
WO2002095334A1
WO2002095334A1 PCT/DE2002/001819 DE0201819W WO02095334A1 WO 2002095334 A1 WO2002095334 A1 WO 2002095334A1 DE 0201819 W DE0201819 W DE 0201819W WO 02095334 A1 WO02095334 A1 WO 02095334A1
Authority
WO
WIPO (PCT)
Prior art keywords
magnetic field
sensor
sensors
field sensors
signals
Prior art date
Application number
PCT/DE2002/001819
Other languages
German (de)
French (fr)
Inventor
Jens Hauch
Klaus Ludwig
Original Assignee
Siemens Aktiengesellschaft
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
Application filed by Siemens Aktiengesellschaft filed Critical Siemens Aktiengesellschaft
Priority to EP02726095A priority Critical patent/EP1390696A1/en
Publication of WO2002095334A1 publication Critical patent/WO2002095334A1/en

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
    • G01D5/145—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 relative movement between the Hall device and magnetic fields

Definitions

  • the invention relates to a sensor line for position detection with at least two magnetic field sensors which detect a magnetic field and emit signals which each have a maximum value, a minimum value and an intermediate half level, and to a method for contactless, linear position measurement between two components. with the use of two magnetic field sensors attached to a first component, which detect a magnetic field and emit signals which have a maximum value, a minimum value and an intermediate half level.
  • Magnetic field measurement is used to obtain a distance signal for position measurement by means of relative movements between the permanent magnet and the magnetic field sensor.
  • An example of such an application can be found in WO 00/09972, in which a magnetic field sensor is used as a position sensor for an electromechanical actuator for gas exchange valves of an internal combustion engine.
  • the measuring range that can be covered with such a measuring method regularly depends on the properties of the magnetic field sensor and of the permanent magnet.
  • the achievable spatial resolution is opposite to the measuring range.
  • the magnetic field sensors used in such sensor lines are available in particular in versions in which in a close range between two end positions that of the magnetic sensor sor signal is almost linear, which enables a high resolution of the measurement signal and a precise position determination.
  • the permanent magnet is generally rod-shaped. It can be aligned so that its magnetic axis is perpendicular to the direction of movement with which the permanent magnet is moved over the magnetic field sensor.
  • Magnetic sensor arrangements for position measurement have the advantage that only little construction is required, in particular the sensors and permanent magnets can be kept very small. In addition, they are very robust and particularly insensitive to contamination.
  • the output signal of the magnetic field sensor is normally converted, in particular if, as in the case of a linear sensor, it is proportional to the measured field strength, by means of a fixed calibration curve within a predetermined working range, which essentially reflects the aforementioned linear relationship.
  • a switch is made between the signals of the individual magnetic field sensors in such a way that the signal of each sensor is evaluated in the range of optimal resolution and signal strength.
  • the invention is therefore based on the object of increasing the measurement accuracy in a contactless position measurement of the type mentioned at the beginning with two magnetic field sensors and reducing the influences of errors mentioned with regard to temperature dependence and mechanical component tolerances.
  • This object is achieved with the aid of a sensor line for contactless, linear position measurement with at least two magnetic field sensors which detect a magnetic field and emit the signals which have a maximum value, a minimum value and an intermediate half level in that the magnetic field sensors are spaced apart that a magnetic field sensor emits a maximum value when the immediately adjacent magnetic field sensor emits a signal at half level.
  • This sensor arrangement enables a particularly advantageous signal evaluation with a favorable signal / noise ratio.
  • the staggering of the magnetic field sensors is no longer dependent on the mere extension of the sensors, as one would actually expect, but is instead related to the signal emitted by the sensors.
  • the sensitivity of the magnetic field sensors and the expansion and field strength of the magnetic field source therefore play a role.
  • the spacing of the magnetic field sensors should therefore preferably be selected depending on the application.
  • the magnetic field sensors of the sensor line according to the invention can in principle be matched to a wide variety of magnetic field sources. Both existing ones are suitable for this Magnetic field sources and specially set up for measuring purposes. It is advantageous and economical if the magnetic field sensors of a sensor line that can be attached to a first component are set to a permanent magnet attached to a second component and emit signals that are dependent on its position. It is advantageous that the spacing of the magnetic field sensors in the sensor line is selected to match the extent of the magnetic field source, for example a permanent magnet.
  • the object is also achieved by a method for contactless, linear position measurement using a sensor line according to the invention, in which the signals of two immediately adjacent magnetic field sensors are divided and formed from the result of the arc tangent as a distance signal which relates to the lateral position of the permanent magnet of the two magnetic field sensors whose signals are divided.
  • the invention then achieves extensive independence with regard to temperature or mechanical misalignment errors without resorting to external characteristics or further sensors.
  • the calculation rule according to the invention for the first and the second magnetic field sensor signal produces a straight characteristic curve over a relatively large working range, which is almost completely independent of the distance between the permanent magnet and the magnetic field sensor.
  • the method according to the invention also has the advantage that, regardless of the location of the magnetic field source, a valid signal is present immediately after the method is started. A previous movement of the magnetic field source, for example over the entire measuring range of a magnetic field sensor, as in the prior art, is not necessary.
  • the method according to the invention thus achieves so-called “true power on” properties, which is extremely advantageous particularly in automotive applications.
  • the method according to the invention can further greatly reduce the effort required for the exact adjustment of the distance between the magnetic field source and the magnetic field sensors, as a result of which the area of application for such contactless position measuring systems is greatly increased.
  • the sensitivity to errors decreases on movements of the magnetic field source that are not parallel to the plane in which the magnetic field sensor is located.
  • the method according to the invention makes magnetic field measurements not only suitable for straight-line movements, but also for slightly curved or oblique movements.
  • the method according to the invention provides a linear relationship between the calculated distance signal and the position of the magnetic field source with respect to the magnetic field sensors.
  • three or more magnetic field sensors can be staggered to cover a larger measuring range.
  • Two distance signals are formed from the signals from two adjacent magnetic field sensors and evaluated in a hysteresis.
  • a sensor line in which more than two magnetic field sensors are spaced along a longitudinal axis on which the magnetic field source moves can cover an almost arbitrarily large measuring range.
  • the advantages of the measurement Process also used over a large measuring distance that is larger than the working range of two magnetic field sensors.
  • 1 is a schematic representation of a sensor line for contactless position measurement
  • Fig. 5 examples of the evaluation of the distance signals of two adjacent magnetic field sensors using a hysteresis loop.
  • the sensor line 1 shows a schematic illustration for contactless position measurement by means of magnetic field sensors which are fastened to a first component and a permanent magnet which is fastened to a second component which is movable relative to the first component.
  • the sensor line 1 shown there has several linear Hall sensors 2a, 2b and 2c, which are attached at a sensor distance d to one another on the sensor line.
  • the sensor line 1 is attached to a first component (not shown).
  • the permanent magnet 3 is attached to a (not shown) second component, which is opposite the first component in the longitudinal direction x. There is an air gap h between the permanent magnet 3 and the sensor line 1, the dimension of which is dependent on the component tolerance and temperature.
  • the permanent magnet 3 is aligned with its magnetization axis between north pole N and south pole S parallel to the longitudinal direction x, but can also be different depending on the measurement task.
  • Each Hall sensor 2a to 2c measures the magnetic field of the permanent magnet 3.
  • FIG. 1 shows a sensor row 1 with a plurality of Hall sensors 2a to 2c. It is also possible to use only two Hall sensors 2a and 2b if the measuring range over which a displacement between permanent magnet 3 and Hall sensor 2a and 2b is to be detected in the longitudinal direction x is sufficiently small.
  • the sensor signal S emitted by each Hall sensor 2a to 2c is shown in a family of curves 4 in FIG. 2.
  • the signal S is plotted in FIG. 2 as a function of the longitudinal direction x and is obtained from a sensor which outputs a voltage between 0 and 5 volts.
  • the family of curves 4 contains various sensor signals S, the air gap h being the family of parameters.
  • each sensor signal S of the family of curves 4 has a maximum value 6 and a minimum value 7.
  • a half level 8 lies between the maximum value 6 and the minimum value 7. This half level 8 is assumed when the permanent magnet 3 lies exactly in the center above the Hall sensor 2.
  • the curve groups 4a and 4b of the two Hall sensors 2a and 2b with different sizes of the air gap h, that is to say different distances of the permanent magnet 3 from the Hall sensors 2a to 2c, are shown in FIG. 3.
  • the distance d between the Hall sensors is chosen such that the curve group 4a of the Hall sensor 2a shows the maximum value 6 precisely when the signal emitted by the Hall sensor 2b has exactly half level.
  • FIG. 4 illustrates the situation with three sensors 2a to 2c for a constant value of the air gap h.
  • the maximum values 6a to 6c like the minimum values 7a to 7c and the half levels 8a to 8c, are at a constant distance from one another corresponding to the distance d between the sensors 2a to 2c.
  • the distance d between the Hall sensors 2a to 2c is such that the Hall sensor 2a outputs a maximum value 6a when the curve 4b of the following Hall sensor 2b reaches the half level 8b, and its maximum value 6b in the longitudinal direction x in turn with the half level 8c of the curve 4c of the Hall sensor 2c coincides.
  • the air gap h is a critical measure for the installation adjustment of the permanent magnet 7 with respect to the sensor line 1.
  • the air gap h changes due to temperature influences.
  • the sensor signal S there is a further dependency of the sensor signal S on the coercive force of the permanent magnet 3, which is usually also temperature-dependent. Therefore, the quotient of two sensor signals S, e.g. of the Hall sensors 2a and 2b, and the arc tangent T is calculated as a distance signal.
  • the evaluation signal has a working range a with an almost constant slope. If the measuring range is now expanded by the use of more than two magnetic field sensors, 2 evaluation curves 9ab and 9bc are obtained with the above-described distance d between the sensors, with working areas a overlapping in the longitudinal direction x over a wide range. The overlap is used in the form of a hysteresis at the transition between the individual characteristic curves 9ab and 9bc of curves 4a, 4b and 4c of the individual Hall sensors 2a, 2b and 2c.
  • the hysteresis arises from the fact that, with a movement extending in the longitudinal direction x, jumping from approximately the middle of the working area a of the evaluation curve 9ab to the subsequent evaluation curve 9bc. In the case of an opposite movement in decreasing longitudinal direction x, the next characteristic curve is jumped from approximately the middle of the working range of the respective characteristic curve.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Transmission And Conversion Of Sensor Element Output (AREA)
  • Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)

Abstract

The invention relates to a method for contactless, linear measurement, wherein a sensor line is provided with at least two magnetic field sensors (2a-c) which give off signals which respectively have a maximum value (6), a minimum value (7) and a half value (8) lying therebetween. The magnetic field sensors (2a-c) are distanced from each other in such a way that a magnetic field sensor (2a) gives off a maximum value (6) if the immediately adjacent sensor emits a signal having a half value (8). The signals of two directly adjacent magnetic field sensors are divided for evaluation and the arc tangent is formed from the result thereof.

Description

Beschreibungdescription
Verfahren zur kontaktlosen, linearen PositionsmessungMethod for contactless, linear position measurement
Die Erfindung bezieht sich auf eine Sensorzeile zur Positionserfassung mit mindestens zwei Magnetfeldsensoren, die ein Magnetfeld detektieren und Signale abgeben, welche jeweils einen Maximalwert, einen Minimalwert und einen dazwischenliegenden Halbpegel aufweisen, und auf ein Verfahren zur kon- taktlosen, linearen Positionsmessung zwischen zwei Bauteilen, mit der Verwendung zweier an einem ersten Bauteil befestigten Magnetfeldsensoren, die ein Magnetfeld detektieren und Signale abgeben, welche einen Maximalwert, einen Minimalwert und einen dazwischenliegenden Halbpegel aufweisen.The invention relates to a sensor line for position detection with at least two magnetic field sensors which detect a magnetic field and emit signals which each have a maximum value, a minimum value and an intermediate half level, and to a method for contactless, linear position measurement between two components. with the use of two magnetic field sensors attached to a first component, which detect a magnetic field and emit signals which have a maximum value, a minimum value and an intermediate half level.
Das Prinzip solcher Sensoranordnungen ist im Stand der Technik zur kontaktlosen Positionsmessung bekannt. Dabei wird die Magnetfeldmessung eingesetzt, um durch Relativbewegungen zwischen Permanentmagnet und Magnetfeldsensor ein Abstandssignal zur Positionsmessung zu gewinnen. Ein Beispiel für eine solche Anwendung findet sich in der WO 00/09972, bei der ein Magnetfeldsensor als Positionssensor für einen elektromecha- nischen Stellantrieb für Gaswechselventile einer Brennkraftmaschine eingesetzt wird.The principle of such sensor arrangements is known in the prior art for contactless position measurement. Magnetic field measurement is used to obtain a distance signal for position measurement by means of relative movements between the permanent magnet and the magnetic field sensor. An example of such an application can be found in WO 00/09972, in which a magnetic field sensor is used as a position sensor for an electromechanical actuator for gas exchange valves of an internal combustion engine.
Der Messbereich, der mit einem solchen Messverfahren abgedeckt werden kann, hängt regelmäßig von den Eigenschaften des Magnetfeldsensors sowie des Permanentmagneten ab. Dabei ist die erreichbare Ortsauflösung gegenläufig zum Messbereich. Um bei gleichbleibender Auflösung einen größeren Messbereich abdecken zu können, ist es bekannt, mehrere Sensoren entlang einer Längsachse aufzureihen, so dass eine Sensorzeile erhalten wird.The measuring range that can be covered with such a measuring method regularly depends on the properties of the magnetic field sensor and of the permanent magnet. The achievable spatial resolution is opposite to the measuring range. In order to be able to cover a larger measuring range with a constant resolution, it is known to line up a plurality of sensors along a longitudinal axis, so that a sensor line is obtained.
Die in solchen Sensorzeilen verwendeten Magnetfeldsensoren sind insbesondere in Ausführungen verfügbar, bei denen in einem Nahbereich zwischen zwei Endpositionen das vom Magnetsen- sor abgegebene Signal annähernd linear verläuft, wodurch eine hohe Auflösung des Messsignals und eine präzise Positionsbestimmung möglich ist. Bei derartigen linearen Magnetfeldsensoren ist der Permanentmagnet in der Regel stabförmig ausge- bildet. Er kann so ausgerichtet werden, dass seine Magnetachse senkrecht zur Bewegungsrichtung, mit der der Permanentmagnet über den Magnetfeldsensor bewegt wird, liegt.The magnetic field sensors used in such sensor lines are available in particular in versions in which in a close range between two end positions that of the magnetic sensor sor signal is almost linear, which enables a high resolution of the measurement signal and a precise position determination. In the case of such linear magnetic field sensors, the permanent magnet is generally rod-shaped. It can be aligned so that its magnetic axis is perpendicular to the direction of movement with which the permanent magnet is moved over the magnetic field sensor.
Magnetsensoranordnungen zur Positionsmessung haben den Vor- teil, dass nur geringer baulicher Aufwand nötig ist, insbesondere können die Sensoren und Permanentmagneten sehr klein gehalten werden. Darüber hinaus sind sie sehr robust und insbesondere verschmutzungsunanfällig. Zur Auswertung wird normalerweise das Ausgangssignal des Magnetfeldsensors, insbe- sondere wenn es, wie bei einem linearen Sensor, proportional zur gemessenen Feldstärke ist, mittels einer festen Kalibra- tionskurve innerhalb eines vorgegebenen Arbeitsbereiches, der im wesentlichen den vorerwähnten linearen Zusammenhang wiedergibt, umgesetzt. Zur Auswertung der Magnetfeldsensoren ei- ner Sensorzeile wird dabei jeweils so zwischen den Signalen der einzelnen Magnetfeldsensoren umgeschaltet, dass das Signal eines jeden Sensors im Bereich optimaler Auflösung und Signalstärke ausgewertet wird.Magnetic sensor arrangements for position measurement have the advantage that only little construction is required, in particular the sensors and permanent magnets can be kept very small. In addition, they are very robust and particularly insensitive to contamination. For evaluation purposes, the output signal of the magnetic field sensor is normally converted, in particular if, as in the case of a linear sensor, it is proportional to the measured field strength, by means of a fixed calibration curve within a predetermined working range, which essentially reflects the aforementioned linear relationship. In order to evaluate the magnetic field sensors of a sensor line, a switch is made between the signals of the individual magnetic field sensors in such a way that the signal of each sensor is evaluated in the range of optimal resolution and signal strength.
Dabei müssen jedoch SignalSchwankungen durch Einbautoleranzen hinsichtlich der gegenseitigen Lage von Permanentmagnet und Magnetfeldsensor so gering wie möglich gehalten werden, da die Signale der Magnetfeldsensoren stark vom Abstand des Permanentmagneten abhängen, mit dem dieser über die Sensorzeile geführt wird. Auch sind Magnetfeldmessungen bei Anwendungen, bei denen starke Temperaturunterschiede auftreten können, nicht besonders vorteilhaft, da Temperaturänderungen zum einen in der Regel eine Änderung des Abstandes zwischen Magnetfeldsensor und Permanentmagnet mit sich bringen und zum ande- ren die Koerzitivkraft der meisten Permanentmagneten stark von der Temperatur abhängt. Für Anwendungen, bei denen die dadurch bedingten Fehler nicht tolerierbar sind, bzw. bei de- nen deren Vermeidung zu unverhältnismäßig hohen Kosten führen würde, sind andere Sensoren bekannt, beispielsweise mit optischen Sensorkonzepten. Diese sind jedoch in der Regel teurer und haben andere Nachteile, wie Verschmutzungsanfälligkeit. Auch ist es möglich, nach Temperaturmessungen eine Fehlerkorrektur vorzunehmen. Dies ist aber ebenfalls aufwendig.However, signal fluctuations due to installation tolerances with regard to the mutual position of the permanent magnet and magnetic field sensor must be kept as low as possible, since the signals of the magnetic field sensors strongly depend on the distance of the permanent magnet with which it is guided over the sensor line. Also, magnetic field measurements are not particularly advantageous in applications in which large temperature differences can occur, since temperature changes on the one hand generally result in a change in the distance between the magnetic field sensor and the permanent magnet and, on the other hand, the coercive force of most permanent magnets is strongly dependent on the temperature , For applications in which the errors caused by this cannot be tolerated or where If their avoidance would lead to disproportionately high costs, other sensors are known, for example with optical sensor concepts. However, these are usually more expensive and have other disadvantages, such as susceptibility to contamination. It is also possible to correct errors after temperature measurements. But this is also expensive.
Der Erfindung liegt deshalb die Aufgabe zugrunde, bei einer kontaktlosen Positionsmessung der eingangs erwähnten Art mit zwei Magnetfeldsensoren die Messgenauigkeit zu steigern und die erwähnten Fehlereinflüsse hinsichtlich Temperaturabhängigkeit und mechanischer Bauteiletoleranzen zu verringern.The invention is therefore based on the object of increasing the measurement accuracy in a contactless position measurement of the type mentioned at the beginning with two magnetic field sensors and reducing the influences of errors mentioned with regard to temperature dependence and mechanical component tolerances.
Diese Aufgabe wird mit Hilfe einer Sensorzeile zur kontaktlo- sen, linearen Positionsmessung mit mindestens zwei Magnetfeldsensoren, die ein Magnetfeld detektieren und die Signale abgeben, welche einen Maximalwert, einen Minimalwert und einen dazwischenliegenden Halbpegel aufweisen, erfindungsgemäß dadurch gelöst, dass die Magnetfeldsensoren so beabstandet sind, dass ein Magnetfeldsensor einen Maximalwert abgibt, wenn der unmittelbar benachbarte Magnetfeldsensor ein Signal mit Halbpegel abgibt.This object is achieved with the aid of a sensor line for contactless, linear position measurement with at least two magnetic field sensors which detect a magnetic field and emit the signals which have a maximum value, a minimum value and an intermediate half level in that the magnetic field sensors are spaced apart that a magnetic field sensor emits a maximum value when the immediately adjacent magnetic field sensor emits a signal at half level.
Diese Sensoranordnung ermöglicht eine besonders vorteilhafte Signalauswertung mit günstigem Signal/Rausch-Verhältnis . Die Staffelung der Magnetfeldsensoren ist erfindungsgemäß nicht mehr von der bloßen Ausdehnung der Sensoren abhängig, wie man eigentlich erwarten würde, sondern wird auf das von den Sensoren abgegebene Signal bezogen. Mithin spielen die Empfind- lichkeit der Magnetfeldsensoren und die Ausdehnung sowie die Feldstärke der Magnetfeldquelle eine Rolle. Die Beabstandung der Magnetfeldsensoren ist somit vorzugsweise anwendungsabhängig zu wählen.This sensor arrangement enables a particularly advantageous signal evaluation with a favorable signal / noise ratio. According to the invention, the staggering of the magnetic field sensors is no longer dependent on the mere extension of the sensors, as one would actually expect, but is instead related to the signal emitted by the sensors. The sensitivity of the magnetic field sensors and the expansion and field strength of the magnetic field source therefore play a role. The spacing of the magnetic field sensors should therefore preferably be selected depending on the application.
Die Magnetfeldsensoren der erfindungsgemäßen Sensorzeile können prinzipiell auf unterschiedlichste Magnetfeldquellen abgestimmt sein. Dazu eignen sich sowohl bereits vorhandene Magnetfeldquellen als auch speziell zu Messzwecken eingerichtete. Vorteilhaft und wirtschaftlich ist es, wenn die Magnetfeldsensoren einer Sensorzeile, die an einem ersten Bauteil befestigbar ist, auf einen an einem zweiten Bauteil befestigten Permanentmagneten eingestellt sind und Signale abgeben, die von dessen Lage abhängig sind. Vorteilhaft ist es, dass die Beabstandung der Magnetfeldsensoren in der Sensorzeile passend zur Ausdehnung der Magnetfeldquelle, beispielsweise eines Permanentmagneten, gewählt wird.The magnetic field sensors of the sensor line according to the invention can in principle be matched to a wide variety of magnetic field sources. Both existing ones are suitable for this Magnetic field sources and specially set up for measuring purposes. It is advantageous and economical if the magnetic field sensors of a sensor line that can be attached to a first component are set to a permanent magnet attached to a second component and emit signals that are dependent on its position. It is advantageous that the spacing of the magnetic field sensors in the sensor line is selected to match the extent of the magnetic field source, for example a permanent magnet.
Prinzipiell sind für die erfindungsgemäße Sensorzeile alle geeigneten Magnetfeldsensoren tauglich, die ein entsprechendes Signal abgeben, das zwischen einem Maximalwert und einem Minimalwert mit dazwischenliegendem Halbpegel schwankt, wenn der Permanentmagnet über die Magnetfeldsensoren geführt wird. Besonders hohe Messgenauigkeiten ergaben sich mit linearen Hallsensoren, weshalb es zu bevorzugen ist, lineare Hallsensoren als Magnetfeldsensoren zu verwenden.In principle, all suitable magnetic field sensors are suitable for the sensor line according to the invention, which emit a corresponding signal that fluctuates between a maximum value and a minimum value with an intermediate half level when the permanent magnet is guided over the magnetic field sensors. Linear Hall sensors gave particularly high measurement accuracies, which is why it is preferable to use linear Hall sensors as magnetic field sensors.
Die Aufgabe wird zudem gelöst durch ein Verfahren zur kontaktlosen, linearen Positionsmessung unter Verwendung einer erfindungsgemäßen Sensorzeile, bei dem die Signale zweier unmittelbar benachbarter Magnetfeldsensoren dividiert und vom Ergebnis der Arcus-Tangens gebildet wird als ein Abstandssig- nal, das die seitliche Lage des Permanentmagneten bezüglich der beiden Magnetfeldsensoren, deren Signale dividiert werden, wiedergibt.The object is also achieved by a method for contactless, linear position measurement using a sensor line according to the invention, in which the signals of two immediately adjacent magnetic field sensors are divided and formed from the result of the arc tangent as a distance signal which relates to the lateral position of the permanent magnet of the two magnetic field sensors whose signals are divided.
Die Erfindung erreicht dann ohne Rückgriff auf externe Kenn- linien oder weitere Sensorik eine weitgehende Unabhängigkeit hinsichtlich Temperatur- oder mechanischer Dejustagefehler . Überraschenderweise zeigte sich, dass die erfindungsgemäße Rechenregel für das erste und das zweite Magnetfeldsensorsignal über einen relativ großen Arbeitsbereich eine gerade Kennlinie ergibt, die so gut wie vollständig unabhängig vom Abstand zwischen Permanentmagnet und Magnetfeldsensor ist. Durch das erfindungsgemäße Verfahren ergibt sich weiter der Vorteil, dass unabhängig von der örtlichen Lage der Magnet- feldquelle sofort nach Aufnahme des Verfahrens ein gültiges Signal vorliegt. Eine vorherige Bewegung der Magnetfeldquelle, beispielsweise über den kompletten Messbereich eines Magnetfeldsensors, wie beim Stand der Technik, ist nicht erforderlich. Das erfindungsgemäße Verfahren erreicht also soge- nannte „True Power On" Eigenschaften, was insbesondere bei automobilen Anwendungen äußerst vorteilhaft ist.The invention then achieves extensive independence with regard to temperature or mechanical misalignment errors without resorting to external characteristics or further sensors. Surprisingly, it was found that the calculation rule according to the invention for the first and the second magnetic field sensor signal produces a straight characteristic curve over a relatively large working range, which is almost completely independent of the distance between the permanent magnet and the magnetic field sensor. The method according to the invention also has the advantage that, regardless of the location of the magnetic field source, a valid signal is present immediately after the method is started. A previous movement of the magnetic field source, for example over the entire measuring range of a magnetic field sensor, as in the prior art, is not necessary. The method according to the invention thus achieves so-called “true power on” properties, which is extremely advantageous particularly in automotive applications.
Durch das erfindungsgemäße Verfahren kann weiter der Aufwand, der zur genauen Justage des Abstandes zwischen Magnetfeld- quelle und den Magnetfeldsensoren erforderlich ist, stark vermindert werden, wodurch der Anwendungsbereich für derartige kontaktlose Positionsmeßsysteme stark vergrößert wird. Darüber hinaus sinkt die Fehlerempfindlichkeit auf Bewegungen der Magnetfeldquelle, die nicht parallel zu der Ebene verlau- fen, in der sich der Magnetfeldsensor befindet. Somit sind durch das erfindungsgemäße Verfahren Magnetfeldmessungen nun nicht nur für geradlinige Bewegungen, sondern auch für leicht bogenförmige oder schräg verlaufende Bewegungen tauglich.The method according to the invention can further greatly reduce the effort required for the exact adjustment of the distance between the magnetic field source and the magnetic field sensors, as a result of which the area of application for such contactless position measuring systems is greatly increased. In addition, the sensitivity to errors decreases on movements of the magnetic field source that are not parallel to the plane in which the magnetic field sensor is located. Thus, the method according to the invention makes magnetic field measurements not only suitable for straight-line movements, but also for slightly curved or oblique movements.
Das erfindungsgemäße Verfahren liefert in einem gewissen Arbeitsbereich einen linearen Zusammenhang zwischen dem errechneten Abstandssignal und der Position der Magnetfeldquelle bezüglich der Magnetfeldsensoren. Zur Vergrößerung des Arbeitsbereiches können drei oder mehrere Magnetfeldsensoren gestaffelt werden, um einen größeren Messbereich abzudecken. Dabei werden jeweils zwei Abstandssignale aus den Signalen zweier benachbarter Magnetfeldsensoren gebildet und in einer Hysterese ausgewertet. Somit kann durch eine Sensorzeile, in der mehr als zwei Magnetfeldsensoren entlang einer Längsachse beabstandet aufgereiht sind, auf der sich die Magnetfeldquelle bewegt, ein nahezu beliebig großer Messbereich abgedeckt werden. Damit werden die Vorteile des erfindungsgemäßen Mess- Verfahrens auch über eine große Messstrecke, die größer als der Arbeitsbereich zweier Magnetfeldsensoren ist, ausgenutzt.In a certain working range, the method according to the invention provides a linear relationship between the calculated distance signal and the position of the magnetic field source with respect to the magnetic field sensors. To enlarge the working area, three or more magnetic field sensors can be staggered to cover a larger measuring range. Two distance signals are formed from the signals from two adjacent magnetic field sensors and evaluated in a hysteresis. Thus, a sensor line in which more than two magnetic field sensors are spaced along a longitudinal axis on which the magnetic field source moves can cover an almost arbitrarily large measuring range. The advantages of the measurement Process also used over a large measuring distance that is larger than the working range of two magnetic field sensors.
Die Erfindung wird nachfolgend unter Bezugnahme auf die Zeichnung beispielhalber noch näher erläutert. In der Zeichnung zeigt :The invention is explained in more detail below by way of example with reference to the drawing. The drawing shows:
Fig. 1 eine schematische Darstellung einer Sensorzeile zur kontaktlosen Positionsmessung,1 is a schematic representation of a sensor line for contactless position measurement,
Fig. 2 eine Kurvenschar eines Magnetfeldsensors, über den in verschiedenen Abständen ein Permanentmagnet geführt wird,2 shows a family of curves of a magnetic field sensor, over which a permanent magnet is guided at different intervals,
Fig. 3 Kurvenscharen zweier beabstandeter Magnetfeldsenso- ren, über die in verschiedenen Abständen ein Permanentmagnet geführt wird,3 family of curves of two spaced apart magnetic field sensors, over which a permanent magnet is guided at different intervals,
Fig. 4 Beispiele für die Kurven dreier gestaffelter Magnetfeldsensoren in einer Sensorzeile undFig. 4 examples of the curves of three staggered magnetic field sensors in a sensor line and
Fig. 5 Beispiele für die Auswertung der Abstandsignale zweier benachbarter Magnetfeldsensoren mittels einer Hystereseschleife.Fig. 5 examples of the evaluation of the distance signals of two adjacent magnetic field sensors using a hysteresis loop.
Eine schematische Darstellung zur kontaktlosen Positionsmessung mittels Magnetfeldsensoren, die an einem ersten Bauteil befestigt sind, und einem Permanentmagneten, der an einem relativ zum ersten Bauteil beweglichen zweiten Bauteil befestigt ist, zeigt Fig. 1. Die dort dargestellte Sensorzeile 1 weist mehrere lineare Hallsensoren 2a, 2b und 2c auf, die in einem Sensorabstand d zueinander auf der Sensorzeile befestigt sind. Die Sensorzeile 1 ist an einem (nicht dargestellten) ersten Bauteil angebracht.1 shows a schematic illustration for contactless position measurement by means of magnetic field sensors which are fastened to a first component and a permanent magnet which is fastened to a second component which is movable relative to the first component. The sensor line 1 shown there has several linear Hall sensors 2a, 2b and 2c, which are attached at a sensor distance d to one another on the sensor line. The sensor line 1 is attached to a first component (not shown).
Über der Sensorzeile 1 bewegt sich in Längsrichtung x einX moves in the longitudinal direction above the sensor line 1
Permanentmagnet 3. Der Permanentmagnet 3 ist an einem (nicht dargestellten) zweiten Bauteil befestigt, das sich gegenüber dem ersten Bauteil in Längsrichtung x verschiebt. Zwischen Permanentmagnet 3 und der Sensorzeile 1 befindet sich ein Luftspalt h, dessen Abmessung bauteiletoleranz- und temperaturabhängig ist. Der Permanentmagnet 3 ist mit seiner Magne- tisierungsachse zwischen Nordpol N und Südpol S parallel zur Längsrichtung x ausgerichtet, kann aber je nach Messaufgabe auch anders liegen. Jeder Hallsensor 2a bis 2c misst das Magnetfeld des Permanentmagneten 3.Permanent magnet 3. The permanent magnet 3 is attached to a (not shown) second component, which is opposite the first component in the longitudinal direction x. There is an air gap h between the permanent magnet 3 and the sensor line 1, the dimension of which is dependent on the component tolerance and temperature. The permanent magnet 3 is aligned with its magnetization axis between north pole N and south pole S parallel to the longitudinal direction x, but can also be different depending on the measurement task. Each Hall sensor 2a to 2c measures the magnetic field of the permanent magnet 3.
In Fig. 1 ist eine Sensorzeile 1 mit mehreren Hallsensoren 2a bis 2c dargestellt. Es können auch nur zwei Hallsensoren 2a und 2b verwendet werden, falls der Messbereich, über den eine Verschiebung zwischen Permanentmagnet 3 und Hallsensor 2a und 2b in Längsrichtung x erfasst werden soll, ausreichend gering ist.1 shows a sensor row 1 with a plurality of Hall sensors 2a to 2c. It is also possible to use only two Hall sensors 2a and 2b if the measuring range over which a displacement between permanent magnet 3 and Hall sensor 2a and 2b is to be detected in the longitudinal direction x is sufficiently small.
Das von jedem Hallsensor 2a bis 2c abgegebene Sensorsignal S ist in Fig. 2 in einer Kurvenschar 4 dargestellt. Das Signal S ist in Fig. 2 als Funktion der Längsrichtung x aufgetragen und von einem Sensor gewonnen, der eine Spannung zwischen 0 und 5 Volt abgibt.The sensor signal S emitted by each Hall sensor 2a to 2c is shown in a family of curves 4 in FIG. 2. The signal S is plotted in FIG. 2 as a function of the longitudinal direction x and is obtained from a sensor which outputs a voltage between 0 and 5 volts.
Die Kurvenschar 4 enthält verschiedene Sensorsignale S, wobei der Luftspalt h der Scharparamenter ist.The family of curves 4 contains various sensor signals S, the air gap h being the family of parameters.
Wie man sieht, weist jedes Sensorsignal S der Kurvenschar 4 einen Maximalwert 6 sowie einen Minimalwert 7 auf. Zwischen Maximalwert 6 und Minimalwert 7 liegt ein Halbpegel 8. Dieser Halbpegel 8 wird dann eingenommen, wenn der Permanentmagnet 3 genau mittig über dem Hallsensor 2 liegt. Die Amplitude zwischen Maximalwert 6 und Minimalwert 7 hängt von der Größe des Luftspaltes h ab. Sie nimmt von einem Luftspalt h = 10 mm, dem flachsten Sensorsignal S der Kurvenschar 4, bis h = 3 mm, den am steilsten verlaufenden Sensorsignal S der Kurvenschar 4, zu. Alle Kurvenscharen haben jedoch den Maximalwert 6 und den Minimalwert 7 sowie den Halbpegel 8 in Längsrichtung x am selben Ort. Die Kurvenscharen 4a und 4b der zwei Hallsensoren 2a und 2b bei verschiedenen Größen des Luftspalts h, also verschiedenen Abständen des Permanentmagneten 3 von den Hallsensoren 2a bis 2c, zeigt Fig. 3. Dabei ist der Abstand d der Hallsensoren so gewählt, dass die Kurvenschar 4a des Hallsensors 2a den Maximalwert 6 jeweils genau dann zeigt, wenn das vom Hallsensor 2b abgegebene Signal genau Halbpegel hat .As can be seen, each sensor signal S of the family of curves 4 has a maximum value 6 and a minimum value 7. A half level 8 lies between the maximum value 6 and the minimum value 7. This half level 8 is assumed when the permanent magnet 3 lies exactly in the center above the Hall sensor 2. The amplitude between maximum value 6 and minimum value 7 depends on the size of the air gap h. It increases from an air gap h = 10 mm, the flattest sensor signal S of the family of curves 4 to h = 3 mm, the steepest sensor signal S of the family of curves 4. However, all families of curves have the maximum value 6 and the minimum value 7 and the half level 8 in the longitudinal direction x at the same location. The curve groups 4a and 4b of the two Hall sensors 2a and 2b with different sizes of the air gap h, that is to say different distances of the permanent magnet 3 from the Hall sensors 2a to 2c, are shown in FIG. 3. The distance d between the Hall sensors is chosen such that the curve group 4a of the Hall sensor 2a shows the maximum value 6 precisely when the signal emitted by the Hall sensor 2b has exactly half level.
Fig. 4 verdeutlicht die Verhältnisse bei drei Sensoren 2a bis 2c für einen konstanten Wert des Luftspalts h. Die Maximalwerte 6a bis 6c weisen wie die Minimalwerte 7a bis 7c und die Halbpegel 8a bis 8c voneinander einen konstanten Abstand entsprechend dem Abstand d der Sensoren 2a bis 2c auf. Der Ab- stand d der Hallsensoren 2a bis 2c ist so, dass der Hallsensor 2a einen Maximalwert 6a abgibt, wenn die Kurve 4b des folgenden Hallsensors 2b den Halbpegel 8b erreicht, und deren Maximalwert 6b in Längsrichtung x ihrerseits mit dem Halbpegel 8c der Kurve 4c des Hallsensors 2c zusammenfällt.FIG. 4 illustrates the situation with three sensors 2a to 2c for a constant value of the air gap h. The maximum values 6a to 6c, like the minimum values 7a to 7c and the half levels 8a to 8c, are at a constant distance from one another corresponding to the distance d between the sensors 2a to 2c. The distance d between the Hall sensors 2a to 2c is such that the Hall sensor 2a outputs a maximum value 6a when the curve 4b of the following Hall sensor 2b reaches the half level 8b, and its maximum value 6b in the longitudinal direction x in turn with the half level 8c of the curve 4c of the Hall sensor 2c coincides.
Der Luftspalt h ist für die EinbauJustierung des Permanentmagneten 7 bezüglich der Sensorzeile 1 ein kritisches Maß. Durch Temperatureinflüsse ändert sich jedoch der Luftspalt h. Darüber hinaus ergibt sich eine weitere Abhängigkeit des Sen- sorsignals S von der Koerzitivkraft des Permanentmagneten 3, welche in der Regel ebenfalls temperaturabhängig ist. Deshalb wird zur Auswertung der Quotient zweier Sensorsignale S, z.B. der Hallsensoren 2a und 2b bestimmt, und davon der Arcus- Tangens T als Abstandssignal berechnet.The air gap h is a critical measure for the installation adjustment of the permanent magnet 7 with respect to the sensor line 1. However, the air gap h changes due to temperature influences. In addition, there is a further dependency of the sensor signal S on the coercive force of the permanent magnet 3, which is usually also temperature-dependent. Therefore, the quotient of two sensor signals S, e.g. of the Hall sensors 2a and 2b, and the arc tangent T is calculated as a distance signal.
Mit diesem Abstandssignal ist eine Größe gewonnen, die eine Auswertung des Signals der Hallsensoren 2a und 2b erlaubt, welche weitestgehend unabhängig vom Luftspalt h und von etwaigen Temperatureinflüssen ist.With this distance signal, a quantity is obtained which allows an evaluation of the signal of the Hall sensors 2a and 2b, which is largely independent of the air gap h and of any temperature influences.
Das Auswertesignal hat, wie die Auswertekurve 9ab in Fig. 5 zeigt, einen Arbeitsbereich a mit nahezu konstanter Steigung. Wird nun der Messbereich durch den Einsatz von mehr als zwei Magentfeldsensoren erweitert, erhält man bei vorbeschriebenem Abstand d der Sensoren 2 Auswertekurven 9ab und 9bc, mit sich in Längsrichtung x über einen weiten Bereich überlappenden Arbeitsbereichen a. Die Überlappung wird in Form einer Hysterese beim Übergang zwischen den einzelnen Kennlinien 9ab und 9bc der Kurven 4a, 4b und 4c der einzelnen Hallsensoren 2a, 2b und 2c ausgenutzt.As the evaluation curve 9ab in FIG. 5 shows, the evaluation signal has a working range a with an almost constant slope. If the measuring range is now expanded by the use of more than two magnetic field sensors, 2 evaluation curves 9ab and 9bc are obtained with the above-described distance d between the sensors, with working areas a overlapping in the longitudinal direction x over a wide range. The overlap is used in the form of a hysteresis at the transition between the individual characteristic curves 9ab and 9bc of curves 4a, 4b and 4c of the individual Hall sensors 2a, 2b and 2c.
Die Hysterese entsteht dadurch, dass bei in zunehmender Längsrichtung x verlaufender Bewegung etwa ab der Mitte des Arbeitsbereiches a der Auswertekurve 9ab auf die anschließende Auswertekurve 9bc gesprungen wird. Bei einer gegenläufigen Bewegung in abnehmender Längsrichtung x wird etwa ab der Mitte des Arbeitsbereiches der jeweiligen Kennlinie auf die nächste Kennlinie gesprungen werden.The hysteresis arises from the fact that, with a movement extending in the longitudinal direction x, jumping from approximately the middle of the working area a of the evaluation curve 9ab to the subsequent evaluation curve 9bc. In the case of an opposite movement in decreasing longitudinal direction x, the next characteristic curve is jumped from approximately the middle of the working range of the respective characteristic curve.
Die im Bereich des Überlappens der A swertekurven 9ab, 9bc ausgeführte Hysterese erlaubt eine eindeutige Zuordnung des Sensorsignals und vermeidet uneindeutige Zuweisungen am Sprungpunkt . The hysteresis carried out in the area of overlap of the value curves 9ab, 9bc allows the sensor signal to be clearly assigned and avoids ambiguous assignments at the jump point.

Claims

Patentansprüche claims
1. Sensorzeile zur Positionserfassung mit mindestens zwei Magnetfeldsensoren (2a, 2b, 2c) , die ein Magnetfeld detektie- ren und Signale (5) abgeben, welche jeweils einen Maximalwert (6) , einen Minimalwert (7) und einen dazwischenliegenden Halbpegel (8) aufweisen, d a d u r c h g e k e n n z e i c h n e t, daß die Magnetfeldsensoren (2a, 2b, 2c) so beabstandet sind, daß ein Magnetfeldsensor (2a, 2b) einen Maximalwert (6a,1. Sensor line for position detection with at least two magnetic field sensors (2a, 2b, 2c) that detect a magnetic field and emit signals (5), each of which has a maximum value (6), a minimum value (7) and an intermediate half level (8) characterized in that the magnetic field sensors (2a, 2b, 2c) are spaced such that a magnetic field sensor (2a, 2b) has a maximum value (6a,
6b) abgibt, wenn der unmittelbar benachbarte Magnetfeldsensor (2b, 2c) ein Signal mit Halbpegel (8b, 8c) abgibt.6b) emits when the immediately adjacent magnetic field sensor (2b, 2c) emits a signal with half level (8b, 8c).
2. Sensorzeile nach Anspruch 1, dadurch gekennzeichnet, daß die Sensorzeile (1) an einem ersten Bauteil befestigbar ist, und die Magnetfeldsensoren (2a, 2b, 2c) von der Lage einer an einem zweiten Bauteil befestigten Magnetfeldquelle (3) abhängige Signale (S) abgeben.2. Sensor line according to claim 1, characterized in that the sensor line (1) can be attached to a first component, and the magnetic field sensors (2a, 2b, 2c) dependent on the position of a magnetic field source (3) attached to a second component signals (S ) submit.
3. Sensorzeile nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß die Magnetfeldsensoren als lineare Hallsensoren (2a, 2b, 2c) ausgebildet sind.3. Sensor line according to claim 1 or 2, characterized in that the magnetic field sensors are designed as linear Hall sensors (2a, 2b, 2c).
4. Verfahren zur kontaktlosen, linearen Positionsmessung mit einer Sensorzeile nach Anspruch 1, bei dem die Signale zweier unmittelbar benachbarter Magnetfeldsensoren dividiert und vom Ergebnis der Arcus-Tangens gebildet wird als ein Abstandssignal, das die seitliche Lage des Permanentmagneten bezüglich der beiden Magnetfeldsensoren, deren Signale divi- diert werden, wiedergibt.4. A method for contactless, linear position measurement with a sensor line according to claim 1, in which the signals of two immediately adjacent magnetic field sensors are divided and formed from the result of the arc tangent as a distance signal, which is the lateral position of the permanent magnet with respect to the two magnetic field sensors, their signals be divided.
5. Verfahren nach Anspruch 4, bei dem eine Sensorzeile mit mehr als zwei Magnetfeldsensoren verwendet wird, wobei je- weils zwei Abstandssignale aus den Signalen zweier benachbarter Magnetfeldsensoren gebildet werden und die zwei Abstandssignale in einer Hysterese ausgewertet werden. 5. The method according to claim 4, in which a sensor line with more than two magnetic field sensors is used, wherein each because two distance signals are formed from the signals of two adjacent magnetic field sensors and the two distance signals are evaluated in a hysteresis.
PCT/DE2002/001819 2001-05-21 2002-05-21 Method for contactless, linear position measurement WO2002095334A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP02726095A EP1390696A1 (en) 2001-05-21 2002-05-21 Method for contactless, linear position measurement

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE2001124761 DE10124761B4 (en) 2001-05-21 2001-05-21 Sensor line and method for contactless, linear position measurement
DE10124761.3 2001-05-21

Publications (1)

Publication Number Publication Date
WO2002095334A1 true WO2002095334A1 (en) 2002-11-28

Family

ID=7685610

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/DE2002/001819 WO2002095334A1 (en) 2001-05-21 2002-05-21 Method for contactless, linear position measurement

Country Status (3)

Country Link
EP (1) EP1390696A1 (en)
DE (1) DE10124761B4 (en)
WO (1) WO2002095334A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1502858A2 (en) * 2003-08-01 2005-02-02 G.D Societ Per Azioni Automatic machine for processing articles and having a position detecting device with hall-effect sensors
EP1674395A1 (en) * 2004-12-23 2006-06-28 G.D S.p.A. A device for transferring and inspecting groups of cigarettes

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102012112216A1 (en) * 2012-12-13 2014-06-18 Conti Temic Microelectronic Gmbh Method for determining position on traverse path, involves arranging encoder magnet on traverse path in movable manner, where position to be determined is defined through position of encoder magnet
DE102016206905A1 (en) 2016-04-22 2017-10-26 Festo Ag & Co. Kg Sensor system and method for determining a position of a measuring element along a movement path

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0422225A1 (en) * 1988-08-31 1991-04-17 Fanuc Ltd. Magnetic absolute position encoder
EP0478394A1 (en) * 1990-09-28 1992-04-01 Kayaba Kogyo Kabushiki Kaisha Displacement detecting apparatus
US5892161A (en) * 1997-09-09 1999-04-06 Tyco Group S.A.R.L. Transducer assembly for an electronically monitored mechanical pipette

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3443176C1 (en) * 1984-11-27 1990-11-15 Angewandte Digital Elektronik Gmbh, 2051 Brunstorf Procedure for the calibration of an electronic position transmitter
DE19632656A1 (en) * 1996-08-13 1998-02-19 Ruf Electronics Gmbh Absolute magnetic encoding

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0422225A1 (en) * 1988-08-31 1991-04-17 Fanuc Ltd. Magnetic absolute position encoder
EP0478394A1 (en) * 1990-09-28 1992-04-01 Kayaba Kogyo Kabushiki Kaisha Displacement detecting apparatus
US5892161A (en) * 1997-09-09 1999-04-06 Tyco Group S.A.R.L. Transducer assembly for an electronically monitored mechanical pipette

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1502858A2 (en) * 2003-08-01 2005-02-02 G.D Societ Per Azioni Automatic machine for processing articles and having a position detecting device with hall-effect sensors
EP1502858A3 (en) * 2003-08-01 2005-04-13 G.D Societ Per Azioni Automatic machine for processing articles and having a position detecting device with hall-effect sensors
US6978877B2 (en) 2003-08-01 2005-12-27 G.D Societa' Per Azioni Automatic machine for processing articles and having a position detecting device with hall-effect sensors
CN100519350C (en) * 2003-08-01 2009-07-29 吉第联合股份公司 Automatic machine for processing articles
EP1674395A1 (en) * 2004-12-23 2006-06-28 G.D S.p.A. A device for transferring and inspecting groups of cigarettes
US7779846B2 (en) 2004-12-23 2010-08-24 G.D. S.P.A. Device for transferring and inspecting groups of cigarettes

Also Published As

Publication number Publication date
EP1390696A1 (en) 2004-02-25
DE10124761A1 (en) 2003-02-20
DE10124761B4 (en) 2004-02-19

Similar Documents

Publication Publication Date Title
EP2182330B1 (en) Positioning / distance measuring system with encoded measurement body
EP1295089B1 (en) Device for contactless measurement of a displacement path, especially for the detection of position and movement
EP0726448B1 (en) Magnetic position sensor
EP1158276A1 (en) Inductive position sensor
EP1081454A1 (en) Inductive position sensor
DE19855358A1 (en) Path-measuring device, especially for brake pedal movement in vehicle has at least one analog sensor and at least one incremental sensor to output analog and pulse train signals of path, respectively
DE102017222676A1 (en) displacement sensor
WO2001063213A1 (en) Measuring device for contactlessly detecting a ferromagnetic object
DE102006010780A1 (en) Position measuring system for hydraulic cylinders
EP1662232A1 (en) Linear position sensor
EP1390695A1 (en) Method for non-contact linear position measurement
EP2149784A1 (en) Magnetic path sensor system
DE102007036202A1 (en) Magnetic field sensor i.e. speed sensor, testing and simulation circuit for e.g. motor vehicle wheel, has frequency generator activating magnetic coils, where magnetic field produced by coils is phase shifted against each other
EP1390696A1 (en) Method for contactless, linear position measurement
DE102011000486A1 (en) Coded magnetostrictive absolute position measuring system, particularly length measuring system for determining position of two objects, comprises magnetic code carrier which is arranged at object
DE10162849B4 (en) Length measuring system in which a scale is moved relative to the position of spaced length sensors
DE19612422A1 (en) Potentiometer with linearly movable slider and magnetic sensor
CH696859A5 (en) Current sensor having a plurality of magnetic field sensors.
EP1992914B1 (en) Incremental displacement sensor and method for determining the displacement of an object relative to another object
EP3617658B1 (en) Sensor
DE10123539A1 (en) Magnetic length measuring device for workpieces during machining has all electronic systems located in sensor housing
EP0873497B1 (en) Device for the detection of deflections of a magnetic body
EP3583388B1 (en) Sensor device
DE102006042580A1 (en) Valve position i.e. hydraulic regulating valve, measuring device for active chassis stabilization system, has sensor responding to change in magnetic field, and comprising two sensor units arranged in common housing
DE10135541B4 (en) Electric motor with position measuring system

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE TR

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
WWE Wipo information: entry into national phase

Ref document number: 2002726095

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 2002726095

Country of ref document: EP