DE102018200234A1 - Sensor system for determining at least one rotational property of a rotating element - Google Patents

Abstract

A sensor system (110) for determining at least one rotational property of an element (112) rotating about at least one axis of rotation A is proposed. The sensor system (110) comprises: - at least one first sender wheel (122), wherein the first sender wheel (122) is connectable to at least a first part (116) of a rotating element (112), wherein the first sender wheel (122) further comprises at least two first electrically conductive segments (156) and at least two first electrically non-conductive segments (158), which are each arranged radially about the axis of rotation A, - at least one second encoder wheel (124), wherein the second encoder wheel (124) with at least one second Part (118) of the rotating element (112) is connectable, wherein the second sender wheel (124) at least two second electrically conductive segments (148) and at least two second electrically non-conductive segments (150), each arranged radially about the axis of rotation A. - at least one torsion element (120), wherein the first part (116) and the second part (118) are rotatably coupled to each other by the torsion element (120), - at least e in sensor element (134), wherein the sensor element (134) is arranged, a relative rotation of the first encoder wheel (122) and the second encoder wheel (124) to each other depending on a Überdeckungsmaß the first electrically conductive segments (156) and the second electrically conductive segments (150) to be determined; characterized in that the sensor element (134) at least one excitation coil (138), and at least one two receiver coils (140, 142), which are at least partially circular in shape.

Description

State of the art

Numerous sensors are known from the prior art which detect at least one rotational property of rotating elements. Examples of such sensors are described in Konrad Reif (ed.): Sensors in motor vehicles, 2nd edition, 2012, pages 63-74 and 120-129. For example, a position of a camshaft of an internal combustion engine can be determined relative to a crankshaft with a so-called phase encoder by means of a Hall sensor.

Typically, a donor wheel is mounted on the rotating axle. There may be teeth on the sender wheel that are sensed by the Hall sensor as the camshaft rotates. So will in the DE 10 2012 213 539 A1 a method for determining a phase angle of an adjustable camshaft of an internal combustion engine, which comprises a transmitter wheel and a camshaft adjuster is described. The phase angle of the camshaft is determined on the basis of triggered by the encoder wheel phase edge interrupts and a model that is dependent on at least one operating characteristic of the camshaft adjuster.

In DE 10 2004 019 379 A1 For example, a method and apparatus for determining a differential angle will be described. Torque in a powertrain should be easier and better recorded. For this purpose, it is provided to determine a differential angle at two measuring points by subtracting the rotational angles at the two measuring points in each case applied with a corresponding transmission ratio. From the differential angle can be closed directly to a transmitted torque without detouring over the rotational speed.

Despite the improvements made by such sensor devices, there is still room for improvement. A challenge in many known methods is still to allow a simultaneous determination of a rotation angle of a shaft and a torque.

Disclosure of the invention

In the context of the present invention, therefore, a sensor system for determining at least one rotational property of a rotating element is proposed.

The sensor system comprises at least a first sender wheel. The first encoder wheel is connectable to at least a first part of a rotating element. The first encoder wheel comprises at least two first electrically conductive segments and at least two first electrically non-conductive segments, which are each arranged radially around the axis of rotation. The sensor system comprises at least one second sender wheel. The second encoder wheel is connectable to at least a second part of the rotating element. The second encoder wheel comprises at least two second electrically non-conductive segments and at least two second electrically conductive segments, which are each arranged radially around the axis of rotation. The sensor system further comprises at least one torsion element, wherein the first part and the second part are rotatably coupled to each other by the torsion element and at least one sensor element. The sensor element comprises at least one exciter coil and at least two receiver coils. The excitation coil and the receiver coils are each formed at least partially circular.

In the context of the present invention, a "sensor system" is basically understood to mean any device which is suitable for detecting at least one measured variable. Accordingly, a sensor system for determining at least one rotation property is understood to mean a sensor system which is set up to detect, for example measure, the at least one rotation property and which can generate, for example, at least one electrical signal corresponding to the detected property, such as a voltage or a Electricity. Combinations of properties can also be detected.

In the context of the present invention, a "rotation property" is basically understood to mean a property which at least partially describes the rotation of the rotating element. This may, for example, be an angular velocity, a rotational speed, an angular acceleration, an angular position or another property which may at least partially characterize a continuous or discontinuous, uniform or non-uniform rotation or rotation of the rotating element. For example, the rotation property may be a position, in particular an angular position, an angular acceleration or a combination of at least two of these variables. Other properties and / or other combinations of properties may also be detectable.

In particular, the rotation property may be a rotation angle. The term "rotation" generally refers to a self-imaging of an object with at least one fixed point. When rotated, the distances, lengths, and angles of the object can be changed stay, only one situation can change. During rotation, a point may be fixed that does not change its position. The point can be called a fixed point or center of rotation. During the rotation, in principle all points of the object are shifted by an identical angle of rotation, which can be designated as an angle between P and P '. The object basically only changes its position during rotation, its appearance remains the same. This is because the distance of the points P and P 'to the center of rotation Z remains identical. In the context of the present invention, a "rotation angle" is basically understood to mean an angle about which a geometric object is rotated. The angle of rotation is thus the same for all points of the object. Furthermore, the rotation property may be a torque. The term "torque" generally refers to a rotational action of a force on any rotatably mounted object. The torque basically indicates how strong a force acts on the rotatably mounted object. Decisive for an effect of a force on a rotatable body may be an amount of force, a direction of the force and a distance of a line of action of the force from the axis of rotation. In particular, the sensor system can be configured to determine at least one angle of rotation and at least one torque.

In the context of the present invention, a "rotating element" is basically understood to mean any element which rotates about at least one axis. For example, the rotating element may be a shaft, for example a shaft in an engine, for example a camshaft or a crankshaft. For example, an angular position of a camshaft or a rotational speed of a camshaft or an angular acceleration of a camshaft or a combination of at least two of these variables can be determined. Other properties and / or other combinations of properties may also be detectable.

The rotating element has a first part and a second part. The terms "first part" and "second part" are to be considered as pure descriptions without indicating an order or ranking and, for example, without precluding the possibility that several types of first parts or second parts or exactly one kind may be provided. Furthermore, additional parts, for example, one or more third parts may be present.

The term "torsion element" basically refers to any element which, in the case of a load with a torque and / or a torsional moment, which acts around a longitudinal axis of the element, is deformable, in particular helically deformable. An effect of the torsion moment on the element can cause an object to twist through a twist angle and distort it by a shear angle. The torsion element can in particular be wholly or partly designed as a cylinder, in particular as a hollow cylinder. The first encoder wheel and the second encoder wheel can be rotated by a torsion angle against each other. The torsion angle can therefore correspond to a difference angle between the first encoder wheel and the second encoder wheel. The torsion angle may in particular be 0.25 to 10 °, preferably 0.5 to 5 ° and particularly preferably 1 to 3 °.

The terms "first sender wheel" and "second sender wheel" are to be regarded as pure descriptions without indicating an order or ranking and excluding, for example, without the possibility that several types of first donor wheels or second donor wheels or just one kind may be provided. Furthermore, additional donor wheels, for example, one or more third donor wheels may be present. In the context of the present invention, a "sensor wheel" can in principle be understood to be any component which can be connected to the rotating element and is designed to effect at least one measurable signal, in particular a change in magnetic field, upon connection to the rotating element per revolution of the rotating element.

As already mentioned above, the first sender wheel can be connected to the first part of the rotating element and the second sender wheel can be connected to the second part of the rotating element. The first sender wheel and / or the second sender wheel may, for example, be permanently or reversibly connected or connectable to the rotating element or may also be integrally formed with the rotating element or integrated into the rotating element.

The first sender wheel may have a connecting element, for example a sleeve, wherein the connecting element is set up to firmly connect the first sender wheel to the first part of the rotating element and / or to the torsion element. The connecting element may in particular have a recess and the first part of the rotating element may be at least partially received in the recess. The first encoder wheel may be formed at least partially planar and the connecting element may be at least partially formed as a hollow cylinder. The torsion element may be at least partially enveloped by the connecting element. The second electrically conductive segments and the second electrically non-conductive segments may each radially around the Be arranged connecting element. In particular, the second electrically conductive segments and the second electrically non-conductive segments can each be arranged alternately around the connecting element.

The second sender wheel may have at least one annular element. The term "annular element" basically refers to any element that is completely or at least partially shaped as a ring. The annular element may in particular have a passage opening. The through-hole may be wholly or at least partly of a shape selected from the group consisting of: a circle, an ellipsoid, an oval-shaped. Other embodiments are conceivable in principle. The second sender wheel can be connectable by means of the annular element with the second part of the rotating element. The second electrically conductive segments and the second electrically non-conductive segments may each be arranged radially around the annular element. In particular, the second electrically conductive segments and the second electrically non-conductive segments may each be arranged alternately around the annular element. In particular, the second electrically conductive segments and the second electrically non-conductive segments may each be attached to the annular element. The annular element can be wholly or at least partially made of at least one electrically conductive material, in particular of at least one material with an electrical conductivity of greater than 10 ⁶ S · cm ^-1 . In particular, the annular member may be made of at least one material selected from the group consisting of: aluminum, copper, steel. Other materials are also conceivable.

The first sender wheel and the second sender wheel can be arranged in particular at a distance of 100 .mu.m to 1000 .mu.m, in particular from 200 .mu.m to 800 .mu.m and particularly preferably from 50 .mu.m to 150 .mu.m to each other. However, the first sender wheel and the second sender wheel can also be arranged such that the first sender wheel and the second sender wheel touch.

The first sender wheel and / or the second sender wheel may in particular be configured in a planar manner. Furthermore, the first sender wheel and / or the second sender wheel may have an at least partially circular basic shape.

The terms "first electrically conductive segment", "first electrically non-conductive segment", "second electrically conductive segment" and "second electrically non-conductive segment" are to be regarded as mere descriptions without indicating an order or ranking and without precluding, for example, that a plurality of types of first electrically conductive segments or second electrically conductive segments or in each case exactly one type can be provided. Furthermore, additional segments, for example one or more third electrically conductive segments may be present.

The first electrically conductive segments, the second electrically conductive segments, the first electrically non-conductive segments and / or the second electrically non-conductive segments may each be formed at least partially planar. The first electrically conductive segments, the second electrically conductive segments, the first electrically non-conductive segments and / or the second electrically non-conductive segments may continue to extend transversely, in particular perpendicular to the axis of rotation. In particular, the first electrically conductive segments, the second electrically conductive segments, the first electrically nonconductive segments and / or the second electrically nonconductive segments may be circular sector segments. The term "circular sector" basically denotes any partial area of a circular area which is delimited by at least one circular arc and at least two circular radii. Other forms are conceivable in principle. For example, the segments may be at least partially formed as a pin-shaped, a tooth-shaped or a serrated bulge or recess.

The first encoder wheel may have at least three of the first electrically conductive segments and at least three of the first electrically non-conductive segments, in particular three of the first electrically conductive segments and three of the first electrically non-conductive segments. The second encoder wheel may have at least three of the second electrically conductive segments and at least three of the second electrically non-conductive segments, in particular three of the second electrically conductive segments and three of the second electrically non-conductive segments. In particular, a number of the first electrically non-conductive segments may be identical to a number of the first electrically conductive segments. In particular, a number of the second electrically non-conductive segments may be identical to a number of the segments.

The first electrically non-conductive segments and / or the second electrically non-conductive segments may each be made entirely or at least partially from at least one electrically non-conductive material. The non-conductive material may in particular have an electrical conductivity of less than 10 ^-8 S · cm ^-1 and a resistivity of greater than 10 ⁸ Ω · cm respectively. Furthermore, the first electrically non-conductive segments and / or the second electrically non-conductive segments may be wholly or partly made of a material having poor electrical conductivity. The electrically poorly conductive material may in particular have an electrical conductivity of less than 10 ^-3 S · cm ^-1 . The first electrically nonconductive segments and / or the second electrically nonconductive segments may in particular be wholly or at least partially made from at least one ceramic material and / or from at least one flame retardant and flame retardant composite material comprising at least epoxy resin and at least one glass fiber fabric. Other materials are also conceivable. Furthermore, the first electrically non-conductive segments and / or the second electrically non-conductive segments may be formed as a recess, in particular as a circular sector-shaped recess.

The first electrically conductive segments and / or the second electrically conductive segments may each be wholly or at least partially made of at least one material having an electrical conductivity greater than 10 ⁶ S · cm ^-1 . In particular, the first electrically conductive segments and / or the second electrically conductive segments may be wholly or at least partially made of at least one material selected from the group consisting of: aluminum, copper, steel. Other materials are also conceivable.

The first electrically conductive segments and the first electrically non-conductive segments may each have the same shape. The second electrically conductive segments and the second electrically non-conductive segments may each have the same shape.

The first electrically non-conductive segments may be at an angle α ₁ be spaced apart. The first electrically conductive segments can be at an angle β ₁ be spaced apart. The second electrically non-conductive segments may be at an angle α ₂ be spaced apart. The second electrically conductive segments may be at an angle β ₂ be spaced apart. The angle α ₁ and the angle α ₂ can be essentially the same size. The angle β ₁ and the angle β ₂ can be essentially the same size. The angle α ₁ and the angle β ₁ can be essentially the same size. The angle α ₂ and the angle β ₂ can be essentially the same size. At least one of the angles α ₁ . α ₂ . β ₁ . β ₂ may substantially correspond to the torsion angle or substantially equal to twice the torsion angle. Preferably, a sum of α ₁ and β ₁ and / or a sum of α ₂ and β ₂ essentially correspond to an integer divisor of 360 °. Even slight deviations are tolerated. For example, deviations may be tolerated which are not more than 10%, in particular not more than 5% or even not more than 2% of the absolute value of the angle.

In particular, the first electrically conductive segments can each have a first circular-arc-shaped side, and the first electrically non-conductive segments can each have a second circular-arc-shaped side. The first circular arc-shaped side can be the angle α ₁ span to the axis of rotation and the second arcuate side can the angle β ₁ span to the axis of rotation. In particular, the second electrically conductive segments can each have a third circular-arc-shaped side, and the second electrically non-conductive segments can each have a fourth circular-arc-shaped side. The third circular arc-shaped side can be the angle α ₂ span to the axis of rotation and the fourth circular arc-shaped side can angle β ₂ span to the axis of rotation. The angle α ₁ and the angle α ₂ can be essentially the same size. The angle β ₁ and the angle α ₁ can be essentially the same size. The angle β ₂ and the angle α ₂ can be essentially the same size. The term "spaced apart at an angle" in the context of the present invention basically means that two or more objects, which extend radially from one axis, span the angle to the axis.

The first donor wheel can have a diameter d ₁ and the second encoder wheel may have a diameter d ₂ respectively. The diameter d ₂ The second encoder wheel may preferably be 10 mm to 100 mm, preferably 20 mm to 80 mm, and more preferably 30 mm to 50 mm. The diameter d ₂ can be larger than the diameter d ₁ , In particular, the diameter can be d ₁ from 1 mm to 20 mm, preferably from 2 mm to 15 mm, more preferably from 3 mm to 10 mm, smaller than the diameter d ₂ , The second sender wheel may be arranged between the first sender wheel and the sensor element.

The second encoder wheel can have a radius r _g2 around the axis of rotation. The radius r _g2 can be the diameter d ₂ correspond. In particular, the second electrically conductive segments and / or the second electrically non-conductive segments within the radius r _g2 be arranged around the axis of rotation. The first donor wheel can have a radius r _g1 around the axis of rotation. The radius r _g1 can be the diameter d ₁ correspond. In particular, the second electrically conductive segments and / or the second electrically non-conductive segments within of the radius r _g1 be arranged around the axis of rotation. The radius r _g1 can be greater than the radius r _g2 , The annular element of the second encoder wheel may have a radius r _g0 around the axis of rotation. The radius r _g0 can be smaller than the radius r _g1 ,

In principle, a "sensor element" in the sense of the present invention is understood to mean any device which is set up to detect at least one property or a measured variable, in particular a physical measured variable. The sensor element may in particular be designed to generate at least one sensor signal, in particular at least one electrical sensor signal, for example an analog and / or digital sensor signal. In particular, the detected property may include a position, for example an angular position. In particular, the sensor element may be an inductive magnetic sensor. However, other embodiments are possible in principle. The sensor element can be configured in particular as a printed circuit board. The sensor element may have a passage, and the rotating element, in particular the second part of the rotating element, may be accommodated at least partially in the passage. The sensor element may be arranged below the second encoder wheel. Furthermore, the sensor element may be fixed in relation to a rotation of the rotating element.

The sensor element may comprise at least one coil arrangement. In the context of the present invention, a "coil arrangement" can in principle be understood to mean any device which comprises at least one coil. In the context of the present invention, a "coil" is fundamentally understood to mean any component which has an inductance and is suitable for generating a magnetic field during current flow and / or vice versa. For example, a coil may comprise at least one complete or partially closed conductor loop or winding.

The sensor element comprises, as already stated above, at least one exciter coil and at least two receiver coils. In the context of the present invention, an "exciter coil" can basically be understood to mean a coil which generates a magnetic flux when an electrical voltage and / or an electrical current are applied. The exciter coil may have at least one exciter coil. The exciter coil can therefore also be referred to as a circulating exciter coil. The excitation coil may be configured to be charged with an AC voltage. The alternating voltage can be 1 MHz to 10 MHz, preferably 2 MHz to 5 MHz and particularly preferably 3.5 MHz. The exciter coil may thus be arranged to generate an electromagnetic alternating field. The alternating electromagnetic field may be configured to couple in the receiver coils and induce interactions. In the context of the present invention, a "receiver coil" is basically understood to mean a coil which is set up to generate a signal due to an inductive coupling between the exciter coil and the receiver coil, which signal depends on the inductive coupling. The receiver coils may be disposed within the exciter coil. The first transmitter wheel and / or the second transmitter wheel may be inductively coupled to the receiver coils.

The sensor system may be configured to detect an inductive coupling and / or a change in an inductive coupling between the exciter coil and the receiver coils. In particular, the sensor element can be set up, the inductive coupling caused by a movement and / or a position of the first sender wheel and the second sender wheel and / or the change in the inductive coupling between the exciter coil and the one caused by a movement and / or a position of the sender wheel To detect receiver coils. For this purpose, the sensor element may, for example, have a corresponding evaluation unit. In particular, the evaluation unit can have at least one evaluation circuit. In particular, the evaluation circuit may be configured to evaluate the signals of the position sensor. The evaluation circuit may be, for example, a processor. The evaluation unit can be arranged with the at least one coil arrangement on a common circuit carrier. The evaluation unit can also be arranged separately from the at least one coil arrangement.

A typical value range of a coupling factor may be, for example, -0.3 to +0.3. In this case, a coupling factor can be understood in particular to be an amplitude ratio between a received signal and a transmitted or exciter signal. The coupling factor can in particular run sinusoidally with the angle of rotation.

As already stated above, the excitation coil and the receiver coils are each formed at least partially circular. The term "circular formation" basically refers to a shape of any element that is at least partially shaped like a circle. Deviations from a circular shape are, however, conceivable in principle, so that the element can at least partially have an oval shape and / or an ellipsoidal shape. Also edges to one or more Sections of the element are conceivable in principle. For example, deviations can be tolerated, which are at any point not more than 20%, in particular not more than 10% or even not more than 5% of an absolute value of the circular shape. The term "sectional formation" basically means that any element in one or more sections has a desired shape. The sections can adjoin one another. Furthermore, one or more further sections, which have a different shape than the desired shape, can be arranged between the sections. The element may thus partially have the desired shape. The term "at least sections of training" basically means that any element may have a desired shape in sections. Alternatively, the whole element may have the desired shape. Consequently, the element may be wholly or partially of the desired shape. The exciter coil and the receiver coils can each be arranged about the axis of rotation. Furthermore, the excitation coil and the receiver coils may be arranged concentrically about the axis of rotation. The term "concentric arrangement" basically means that two or more objects are arranged symmetrically about a common axis, in particular around a common center. In particular, the excitation coil and the receiver coils can each be arranged at least in sections in a circle and arranged in different radii, as explained in greater detail below, about an identical axis, in particular about the axis of rotation.

The sensor element may have at least one first receiver coil and at least one second receiver coil. Furthermore, the sensor element can have at least one third receiver coil. The terms "first receiver coil", "second receiver coil" and "third receiver coil" are to be considered as pure descriptions without indicating any order or ranking and, for example, without precluding the possibility of having multiple types of first receiver coils, second receiver coils and third receiver coils, respectively exactly one kind can be provided. Furthermore, additional receiver coils, for example, one or more fourth receiver coils may be present.

The first receiver coil can have a radius r _e1 have about the axis of rotation A. Furthermore, the second receiver coil has a radius r _e2 have about the axis of rotation A. The radius r _e1 can be greater than the radius r _e2 , The exciter coil a radius r _e0 have about the axis of rotation A. The radius r _e3 can be smaller than the radius r _e0 , The radius r _g2 The second encoder wheel can be greater than or equal to the radius r _e2 be the second receiver coil. The radius r _g1 The first encoder wheel can be greater than or equal to the radius r _e1 be the first receiver coil. The sensor element may further comprise the third receiver coil. The third receiver coil can have a radius r _e3 have about the axis of rotation A. The radius r _e3 can be smaller than the radius r _e2 the second receiver coil. The radius r _g0 of the annular element may be greater than or equal to the radius r _e3 be the third receiver coil. The first receiver coil can have a radius r _e1 have about the axis of rotation A. In the context of the present invention, the term "having a radius" can basically be understood to mean that any element is limited by a radius about an axis. The element may therefore be disposed at least partially within the radius about the axis. The radius can be an equivalent radius. In particular, the exciter coil and / or the receiver coils can each have one or more conductor tracks. The conductor tracks may have a cross section, in particular a rectangular cross section with a center point, a plurality of center points may span a line, which are arranged at a distance from the axis of rotation which corresponds to the radius r _e0 . r _e1 . r _e2 or. r _e3 equivalent.

In a further aspect of the present invention, a method is proposed for determining at least one rotational property of an element rotating about at least one axis of rotation. The method is carried out using a sensor system according to the present invention, ie according to one of the above-mentioned embodiments or according to one of the embodiments described in more detail below. Accordingly, for definitions and optional configurations, reference may be made largely to the description of the sensor system. However, other embodiments are possible in principle.

The method according to the invention can comprise the method steps which are described below. The method steps may preferably be carried out in the predetermined order. In this case, one or even several method steps can be performed simultaneously or overlapping in time. Furthermore, one, several or all of the method steps can be carried out simply or repeatedly. The method may additionally comprise further method steps.

1. a) Aufnehmen induktiver Signale mittels des Sensorelements; und
2. b) Auswerten der induktiven Signale und Ermitteln der Rotationseigenschaft mittels der induktiven Signale.

The process steps are:

1. a) receiving inductive signals by means of the sensor element; and
2. b) evaluating the inductive signals and determining the rotation property by means of the inductive signals.

The inductive signals may be voltage signals, in particular voltages generated in the receiver coils. In particular, the voltages in the receiver coils can be generated due to the inductive coupling of the receiver coils with the at least one exciter coil. In particular, the inductive coupling and / or the change in the inductive coupling in the coil arrangement may depend on a movement and / or on a position of the first encoder wheel and / or the second encoder wheel. Furthermore, the method may include determining the angular position of the rotating element and the torque using the detected, dependent on the position and / or the movement of the encoder wheels inductive coupling and / or changing the inductive coupling.

Furthermore, the method may include the processing of the inductive signals by an evaluation circuit. Furthermore, the method may include forwarding the inductive signals to a control device, for example a processor. Furthermore, the method may comprise a determination of the rotational property, for example the angular position, by means of an evaluation of the inductive signals.

The sensor element may comprise the at least one first receiver coil and the at least one second receiver coil. From a difference between a first inductive signal of the first receiver coil and a second inductive signal of the second receiver coil, at least one rotational property can be determined.

In particular, the first receiver coil can be the radius r _e1 have the axis of rotation A and the second receiver coil can the radius r _e2 around the axis of rotation A, where r _e1 > r _e2 . The second encoder wheel can be the radius r _g2 around the axis of rotation, where r _e2 ≤ r _g2 . The first donor wheel the radius r _g1 around the axis of rotation A, where r _e1 ≤ r _g1 . From the difference between the first inductive signal and the second inductive signal, at least one distance between the first encoder wheel and the second encoder wheel can be determined

The sensor element may further comprise at least a third receiver coil. The third receiver coil can be the radius r _e3 around the axis of rotation A, where r _e2 > r _e3 . The second sender wheel can furthermore have the at least one annular element and the second sender wheel can be connectable to the second part of the rotating element by means of the annular element. The annular element can be the radius r _g1 around the axis of rotation, where r _e1 ≤ r _g1 . From a difference between the second inductive signal and a third inductive signal of the third receiver coil, at least one torque can be determined. From the third inductive signal of the third receiver coil can be further closed to a distance between the sensor element and the annular element.

Advantages of the invention

The proposed device and method have numerous advantages over known devices and methods. In particular, the device can be inexpensive, since only one sensor element can be used. Furthermore, a sensor evaluation can basically be very simple, since a calculation effort is reduced. The sensor system can have a small installation space. In addition, the sensor system, in particular through the use of compensation structures, tolerances robust and temperature stable. Furthermore, the method can represent a simple measuring principle and have an easily implementable redundancy principle. Furthermore, the sensor system can have a very high sensitivity and the measuring principle can be independent of many external influences such as humidity, lubricants and interference fields. An application-specific integrated circuit can in principle be used here. Basically, the sensor system can be an externally robust system which, in contrast to magnetic principles, can also be used in an environment of high currents, in particular motor currents, for example in an electric vehicle.

list of figures

Further optional details and features of the invention will become apparent from the following description of preferred embodiments, which are shown schematically in the figures.

• 1 eine schematische Darstellung eines Ausführungsbeispiels eines erfindungsgemäßen Sensorsystems in einer Schnittdarstellung;
• 2A und 2B schematische Darstellungen von Ausführungsbeispielen eines zweiten Geberrads (2A) und eines ersten Geberrads (2B);
• 3A bis 3C verschiedene Ansichten des ersten Geberrads und des zweiten Geberrads in Draufsicht; und
• 4 schematische Darstellung eines exemplarischen Ausführungsbeispiels eines Sensorelements

Show it:

• 1 a schematic representation of an embodiment of a sensor system according to the invention in a sectional view;
• 2A and 2 B schematic representations of embodiments of a second encoder wheel ( 2A) and a first donor wheel ( 2 B) ;
• 3A to 3C different views of the first encoder wheel and the second encoder wheel in plan view; and
• 4 schematic representation of an exemplary embodiment of a sensor element

Embodiments of the invention

In 1 is an embodiment of a sensor system 110 shown. The sensor system 110 comprises a rotating element 112 , In particular, it may be in the rotating element 112 around a wave 114 act. The rotating element has a first part 116 and a second part 118 on. The first part 116 and the second part 118 are through a torsion element 120 connected with each other. The sensor system 110 also has at least one first sender wheel 122 and at least one second sender wheel 124 on. The first donor wheel 122 can with the first part 116 of the rotating element 112 be rigidly connected. The second donor wheel 124 can be a connecting element 126 For example, a sleeve 128 , and the connecting element 126 can the second donor wheel 124 stuck with the second part 118 of the rotating element 112 connect. The connecting element 126 in particular, a recess 130 and the second part 118 of the rotating element 112 can be at least partially in the recess 130 be included. The second donor wheel 131 can be an annular element 132 and the annular element 132 can the second donor wheel 131 stuck with the second part 118 connect the rotating element. Furthermore, the sensor system 110 a sensor element 134 on. The sensor element 134 can be an implementation 136 and the rotating element 112 Can be at least partially in the implementation 136 be included. The sensor element 134 can be below the first sender wheel 122 be arranged. Furthermore, the sensor element 134 stationary with respect to a rotation of the rotating element 112 to be appropriate. The sensor element comprises at least one exciter coil 138 and at least two receiver coils. The sensor element 134 according to 1 can be at least a first receiver coil 140 , at least one second receiver coil 142 and at least a third receiver coil 144 respectively.

The second donor wheel 124 can have a radius r _g2 around the axis of rotation. The first donor wheel can have a radius r _g1 around the axis of rotation. The radius r _g1 can be greater than the radius r _g2 , The annular element 132 of the second encoder wheel 124 can have a radius r _g0 around the axis of rotation. The radius r _g0 can be smaller than the radius r _g1 , The first receiver coil 140 can have a radius r _e1 have about the axis of rotation A. Furthermore, the second receiver coil 142 a radius r _e2 have about the axis of rotation A. The radius r _e1 can be greater than the radius r _e2 , The exciter coil 138 can have a radius r _e0 have about the axis of rotation A. The annular element 132 can have a radius r _g0 have about the axis of rotation A. The radius r _e3 can be smaller than the radius r _e0 , The radius r _g2 of the second encoder wheel 124 can be greater than or equal to the radius r _e2 the second receiver coil 142 his. The radius r _g1 the first donor wheel 122 can be greater than or equal to the radius r _e1 the first receiver coil 140 his. The third receiver coil 144 can have a radius r _e3 have about the axis of rotation A. The radius r _e3 may be smaller than the radius r _e2 the second receiver coil. The radius r _g0 of the annular element may be greater than or equal to the radius r _e3 be the third receiver coil

2A and 2 B show schematic representations of embodiments of a second encoder wheel 124 ( 2A) and a first donor wheel 122 ( 2 B) , The first donor wheel 122 and the second encoder wheel can at least partially the first encoder wheel 122 and the second donor wheel 124 according to 1 correspond to the description of the 1 can be referenced.

The second donor wheel 124 according to 2A can have a circular basic shape. The second donor wheel 124 can be at least two second electrically conductive segments 148 and at least two first electrically non-conductive segments 150 respectively. The second electrically conductive segments 148 and / or the second electrically non-conductive segments 150 can in particular be planar and extend transversely, in particular perpendicular to the axis of rotation A. The second electrically conductive segments 148 and the second electrically non-conductive segments 150 can be configured as circular sector segments. The second electrically non-conductive segments 150 can as a recess 142 be formed, in particular as a circular sector-shaped recess 142 , The second electrically conductive segments 148 and the second electrically non-conductive segments 150 can each have the same shape. The second electrically conductive segments 148 can each have a third arcuate side 152 and the second electrically non-conductive segments 150 can each have a fourth arcuate side 154 respectively. The third circular arc-shaped side 152 can span an angle α ₁ to the rotation axis A and the second circular arc-shaped side 154 can span an angle β ₁ to the rotation axis A. The second donor wheel 124 can have a diameter d ₂ having a double of the radius r _g2 equivalent.

The first donor wheel 122 according to 2 B may be at least two first electrically conductive segments 138 and at least two second electrically non-conductive segments 140 respectively. The second electrically conductive segments 138 and the second electrically non-conductive segments 140 can in particular be planar and extend transversely, in particular perpendicular to the axis of rotation A. The first electrically conductive segments 156 and the first electrically non-conductive segments 158 can be configured as circular sector segments. The first electrically non-conductive segments 156 can as a recess 146 be formed, in particular as a circular sector-shaped recess 142 , The first electrically conductive segments 156 and the first electrically non-conductive segments 158 can each have the same shape. The first electrically conductive segments 156 can each have a first arcuate side 160 and the second electrically non-conductive segments 158 can each have a second arcuate side 162 respectively. The first circular arc-shaped side 160 can be an angle α ₂ span to the rotation axis A and the second circular arc-shaped side 162 can be an angle β ₂ span up to the axis of rotation A. The angle α ₁ and the angle α ₂ can be essentially the same size. The angle β ₁ and the angle α ₁ can be essentially the same size. The angle β ₂ and the angle α ₂ can be essentially the same size. The first donor wheel 122 can have a diameter d ₁ having a double of the radius r _g1 equivalent.

3A to 3C show different views of the first donor wheel 122 and the second encoder wheel 124 in plan view. In 3A No relative rotation is shown in 3B a mean relative twist and in 3C a large relative twist. For maximum sensitivity of the sensor element 134 can be the first donor wheel 122 and the second donor wheel 124 be positioned so rotated relative to each other that they form together in the plan view without acting on a torque together a continuous electrically conductive surface, as in 3A shown. Now it comes to the action of a torque and a relative rotation of the first encoder wheel 122 and the second encoder wheel 124 Depending on the relative angle of rotation, a variable area of an electrically insulating or less conductive surface may result in a plan view, as in FIG 3B and 3C shown. A detection of a size of this surface can allow a conclusion on a twist angle and it can be determined a torque.

In 4 shows a schematic representation of the exemplary embodiment of a sensor element 134 , The sensor element 134 at least largely corresponds to the sensor element 134 as it is in 1 is shown so that at least largely referenced above discussion.

The sensor element 134 has the exciter coil 138 on. Furthermore, the sensor element 134 the first receiver coil 140 , the second receiver coil 142 and the third receiver coil 144 each with the radii r _e0 . r _e1 . r _e2 and r _e3 as explained above. The exciter coil 138 and / or the receiver coils 140 . 142 . 144 can each be at least partially circular and concentric about the axis of rotation A. The exciter coil 138 and / or the receiver coils 140 . 142 . 144 can each as a planar coil 164 be formed, which in one or more levels of a circuit board (not shown) may be integrated. The exciter coil 138 and / or the receiver coils 140 . 142 . 144 are in 4 each represented with one turn. The exciter coil 138 and / or the receiver coils 140 . 142 . 144 However, they can also have several turns. The exciter coil 138 can be acted upon by an alternating voltage having a frequency in the range of a few MHz, preferably 3.5 MHz. As a result, an alternating electromagnetic field can arise, which in the receiver coils 140 . 142 . 144 can couple and induce AC voltages there. The third receiver coil 144 can, regardless of a rotation of the torsion element 120 be permanently covered by an electrically conductive material. In particular, the third receiver coil 144 permanently from the annular element 132 of the second encoder wheel 124 be covered. An induced voltage can thus be a distance between the sensor element 134 and the second donor wheel 124 depend. The second receiver coil 142 may be particularly sensitive to a relative rotation of the first encoder wheel 122 and the second encoder wheel 124 and thus on a torque. The first receiver coil 140 may continue to be set up on the first donor wheel 122 to react. Consequently, a distance measurement can be performed.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102012213539 A1 [0002]
• DE 102004019379 A1 [0003]

Claims (10)

Sensor system (110) for determining at least one rotational property of an element (112) rotating about at least one axis of rotation A, the sensor system (110) comprising: - at least one first encoder wheel (122), the first encoder wheel (122) having at least one first part (116) of a rotating element (112) is connectable, wherein the first encoder wheel (122) further comprises at least two first electrically conductive segments (156) and at least two first electrically non-conductive segments (158), each arranged radially about the axis of rotation A. are; - At least a second encoder wheel (124), wherein the second encoder wheel (124) with at least a second part (118) of the rotating element (112) is connectable, wherein the second encoder wheel (124) at least two second electrically conductive segments (148) and comprises at least two second electrically non-conductive segments (150) which are each arranged radially about the axis of rotation A; - At least one torsion element (120), wherein the first part (116) and the second part (118) by the torsion element (120) are rotatably coupled to each other; - At least one sensor element (134), wherein the sensor element (134) is arranged, a relative rotation of the first encoder wheel (122) and the second encoder wheel (124) to each other depending on a Überdeckungsmaß the first electrically conductive segments (156) and the second electrically determine conductive segments (150); characterized in that the sensor element (134) at least one excitation coil (138), and at least one two receiver coils (140, 142), which are at least partially circular in shape. A sensor system (110) according to the preceding claim, wherein the exciter coil (138) and the receiver coils (140, 142) are concentrically disposed about the axis of rotation A. A sensor system (110) according to any one of the preceding claims, wherein the sensor element (134) comprises at least a first receiver coil (140) and at least a second receiver coil (142), the first receiver coil (140) having a radius r _e1 about the axis of rotation A. wherein the second receiver coil (142) has a radius r _e2 about the axis of rotation A, where r _e1 > r _e2 . A sensor system (110) according to the preceding claim, wherein the second encoder wheel (124) has a radius r _g2 about the axis of rotation A, where r _e2 ≤ r _g2 , wherein the first encoder wheel (122) has a radius r _g1 about the axis of rotation A, where r _e1 ≤ r _g1 . The sensor system (110) according to one of the two preceding claims, wherein the sensor element (134) further comprises at least a third receiver coil, wherein the third receiver coil has a radius r _e3 about the axis of rotation A, where r _e3 <r _e2 . Sensor system (110) according to the preceding claim, wherein the second transmitter wheel (124) has at least one annular element (132), wherein the second transmitter wheel (124) is connected to the second part (118) of the rotating element (132) by means of the annular element (132). 112), wherein the annular member (132) has a radius r _g1 about the axis of rotation A, where r _e1 ≤ r _g1 . Method for determining at least one rotational property of an element (112) rotating about at least one axis of rotation A, the method comprising using at least one sensor system (110) according to one of the preceding claims, the method further comprising the following steps: a) receiving inductive signals by means of the sensor element (134); and b) evaluating the inductive signals and determining the rotation property by means of the inductive signals. The method of the preceding claim, wherein the sensor element (134) comprises at least a first receiver coil (140) and at least a second receiver coil (142), wherein a difference between a first inductive signal of the first receiver coil (140) and a second inductive signal second receiver coil (142) at least one rotation property is determined. A method according to the preceding claim, wherein the first receiver coil (140) has a radius r _e1 about the axis of rotation A, the second receiver coil (142) having a radius r _e2 about the axis of rotation A, where r _e1 > r _e2 , the second one Sender wheel (124) has a radius r _g2 about the axis of rotation, where r _e2 ≦ r _g2 , wherein the first sender wheel (122) has a radius r _g1 about the axis of rotation A, where r _e1 ≦ r _g1 , where the difference between the first inductive signal and the second inductive signal at least a distance between the first encoder wheel (122) and the second encoder wheel (124) is determined. The method of the preceding claim, wherein the sensor element (134) further comprises at least one third receiver coil (144), the third receiver coil (144) having a radius r _e3 about the axis of rotation A, where r _e2 > r _e3 , wherein the second encoder wheel (124) further comprises at least one annular element (132), wherein the second encoder wheel (124) by means of ring-shaped element (132) is connectable to the second part (118) of the rotating element (112), wherein the annular element (132) is arranged within a radius r _g1 about the axis of rotation A, wherein r _e1 ≤ r _g1 , wherein one of Difference between the second inductive signal and a third inductive signal of the third receiver coil (144) at least one torque is determined.

Images