DE102018213648A1 - Sensor system and method for determining at least one rotational property of an element rotating about at least one rotational axis - Google Patents

Abstract

A sensor system (110) is proposed for determining at least one rotational property of an element rotating about at least one axis of rotation (112). The sensor system (110) comprises at least a first sensor (114) and at least a second sensor (116), characterized in that
• the sensor system (110) further comprises at least one magnetic hollow body (118) which can be connected to the rotating element, the magnetic hollow body (118) enclosing an interior space (122) and being rotatably mounted about an axis of rotation (120);
• The first sensor (114) and the second sensor (116) are arranged such that the first sensor (114) and the second sensor (116) each generate a measurement signal as a function of an interaction with a magnetic field of the magnetic hollow body (118) ,

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 a motor vehicle, 2nd edition, 2012, pages 63-74 and 120-129. For example, a position of a camshaft of an internal combustion engine relative to a crankshaft with a phase generator can be determined by means of a Hall sensor.

For example, to implement traction in electric vehicles, either asynchronous machines or synchronous machines are often used, each of which consists of a stationary stator and a rotating rotor. A so-called resolver is often used to determine a rotor speed or a torque. This is usually an electromagnetic transmitter in which a rotor package is mounted on the shaft of the motor in a speed-proof manner. An excitation coil and two receiving coils are mounted on a stator in a circular ring. An AC voltage signal is applied to the excitation coil and passes through the entire arrangement with an alternating electromagnetic field. Depending on the angle of rotation, a sinusoidal amplitude-modulated voltage is now induced in the first receiving coil, while a cosine-shaped amplitude-modulated voltage is induced in the second receiving coil. However, the resolver generally requires a relatively large amount of installation space, involves complex signal preparation and signal processing, and generally has to be installed with very low mechanical tolerances in order to achieve a sufficiently high level of accuracy. For these reasons, the system costs are correspondingly high. Furthermore, for reasons of space, it is generally not possible to mount a redundant receiving coil system on the stator of the resolver in order to increase the availability of the sensor. It follows that failure of the sensor in many cases leads to failure of the vehicle. In addition to electromagnetic resolvers, there were also optical resolvers, such as in DE 10 2013 203 937 A1 described, which, however, in addition to high costs, generally have a cross-sensitivity to contamination and are therefore not suitable for use in every environment.

Also known, for example, are inductive absolute angle sensors, in particular based on an eddy current effect, such as from DE 10 2014 220 458 A1 , Here, for example, a metallic target is moved over sensor coils which are subjected to alternating voltage and induce an eddy current in this target. This leads to a reduction in the coil inductances and allows the frequency of the rotation angle to be deduced via a change in frequency in a resonant circuit. However, this embodiment can, for example, have a high cross sensitivity to mechanical installation tolerances, for example to tilting the target, and a possible locking of the frequencies to external disturbances, for example so-called injection locking. Furthermore, a redundant coil system, which is required to ensure functional safety, doubles the space requirement of the sensor.

Also known, for example from EP 0 909 955 B1 , is another sensor principle based on coupled coils. This type of sensor is characterized in that an alternating electromagnetic field is generated in a single excitation coil, which couples into several receiving coils and induces a voltage there in each case. For the measurement of the angle of rotation, a rotatably mounted, conductive target is required which, depending on its angular position, in particular relative to the coils, influences the inductive coupling between the excitation coil and the receiving coils. Disadvantages here are, for example, the circuitry required to provide the signals and the lack of real-time capability for signal processing. Especially at high speeds, well-known digital interfaces such as SENT are often too slow to provide angle information sufficiently often. Although a redundant sensor signal can be generated without additional space requirement if the coil systems are adequately designed, complex self-diagnostics are necessary in the two application-specific integrated circuits (ASICs) to be used to rule out so-called "common cause errors", for example failures due to at least one common cause , This can sometimes mean that it can be discriminated, in particular differentiated, whether the motor no longer rotates if the outputs of the ASIC signals do not change, or whether both ASICs have an error.

Are further, for example, from DE 4 011 503 A1 , Phase encoder and speed sensor for speed and derived rotation angle measurement in internal combustion engines. On the sensor side, this can be Hall elements, for example, which are applied to a back bias magnet. If a ferromagnetic gearwheel, for example a target, rotates past these Hall elements, this leads to a change in the Hall voltage since the magnetic circuit changes. The Hall signal is advantageous through a Comparator circuit or a Schmitt trigger converted into a digital signal that can trigger real-time ignition of an internal combustion engine, for example. In order to be able to measure, in particular determine, absolute angles with such sensors, it is possible, for example, to use three sensors which are arranged at 120 ° to one another electrically. Variants of this arrangement are also known, such as arrangements with other sensor elements for magnetic field detection, for example magnetoresistive sensor elements instead of Hall elements, or arrangements with alternately magnetized sensor element, for example with a so-called multipole sensor wheel, instead of sensors with an integrated back bias magnet in Combination with ferromagnetic gear. However, such arrangements often have the restriction, for example, that absolute position detection can only be achieved in connection with special tooth / gap patterns, for example by reference gaps on the crankshaft sprocket and varied tooth / gap lengths on the camshaft sprocket. This particularly limits the effectively usable resolution of the speed or position information. A further restriction is that such a sensor solution must be designed to be fully redundant when there are high demands on functional safety, which is not always feasible due to space constraints.

Also known are absolute angle sensors, which are based on the measurement of a spatially resolved magnetic field strength. In principle, a suitably magnetized target is fixedly connected to the shaft and the orientation of the magnetic field lines is detected, similar to a compass. Possible embodiments are based on magnetoresistive effects or the Hall effect and are commercially available. However, redundant implementations are difficult to implement. Common cause errors would also be difficult to detect here, since two identical ASICs are normally used in redundant systems.

Despite the improvements brought about by such sensor devices, there is still room for improvement. Such sensor devices usually have a high requirement for the space required. However, this is not always available.

Disclosure of the invention

Within the scope of the present invention, therefore, a sensor system for determining at least one rotational property of an element rotating about at least one rotational axis and a method for determining at least one rotational property of an element rotating about at least one rotational axis are proposed, which have the disadvantages of the devices known from the prior art and Procedure addressed. In particular, the need for a space in the sensor arrangement is to be reduced.

In a first aspect of the present invention, a sensor system for determining at least one rotational property of an element rotating about at least one rotational axis is proposed. The sensor system comprises at least one first sensor and at least one second sensor. The sensor system further comprises at least one magnetic hollow body that can be connected to the rotating element. The magnetic hollow body includes an interior and is rotatably mounted about an axis of rotation of the magnetic hollow body. The first sensor and the second sensor are arranged such that the first sensor and the second sensor each generate a measurement signal as a function of an interaction with a magnetic field of the magnetic hollow body.

The first sensor can be an incremental angle sensor and can be set up to generate a first signal as a function of a relative angular position of the magnetic hollow body. The second sensor can be an absolute angle sensor and can be set up to generate a second signal as a function of an absolute angular position of the magnetic hollow body.

In the context of the present invention, a “sensor system” is understood in principle to be any device which is suitable for detecting at least one measurement variable. A sensor system for determining at least one rotation property is accordingly understood to be a sensor system which is set up to detect, for example measure, the at least one rotation property and which, for example, can generate at least one electrical signal corresponding to the detected property, such as a voltage or a Electricity. Combinations of properties can also be recorded. In particular, the sensor system can be or comprise a rotor position sensor and / or a rotor position sensor.

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

In the context of the present invention, an “angular position” basically means an angle of rotation of a device capable of rotation, for example the rotating element or a sensor wheel of the sensor system, with respect to an axis perpendicular to the axis of rotation.

In particular, an angular position can refer to a previous angular position, for example refer to an angle of rotation that was present at an earlier point in time. In particular, an angular position referring to a previous angular position can be referred to as an incremental angular position, for example as an incremental angle. Furthermore, an angular position can also be absolute, i.e. H. without reference to a previous angular position. In particular, an angular position that does not relate to a previous angular position, for example not to an angle of rotation, can be referred to as an absolute angular position, for example as an absolute angle.

The term "rotation" generally refers to a self-image of an object with at least one fixed point. With a rotation, distances, lengths and angles of the object can remain unchanged, only one position can change. When rotating, a point can be fixed that does not change its position. The point can be referred to as a fixed point or center of rotation. During rotation, all points of the object are fundamentally shifted by the same angle of rotation, which can be referred to as the angle between P and P '. The object basically only changes its position during rotation, its appearance remains the same. This is because the distance between 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 around which a geometric object is rotated. The angle of rotation is therefore the same at all points of the object.

The sensor system can in particular be set up for use in a motor vehicle. In the context of the present invention, a “rotating element” is basically understood to mean any element that rotates about at least one axis, in particular about an axis of rotation. For example, the rotating element can be a shaft, for example a shaft in a drive machine, 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 can also be ascertainable.

The sensor system can be used in particular in an asynchronous machine or in a synchronous machine, each of which has a stationary stator and a rotating rotor. The asynchronous machine and / or the synchronous machine can be used to implement traction in electric vehicles. The stator can in particular comprise three winding strands, for example offset by 120 ° / p to one another, where p represents a number of pole pairs. In asynchronous machines, the rotor usually comprises electrically conductive rods short-circuited at the ends. When a rotor field is rotated, a voltage can be induced in the rods, which causes a current to flow, which in turn builds up a counter-magnetic field and a rotational movement occurs. The induced voltage is zero if the stator field and rotor rotate at the same speed. There is a speed difference, which is referred to as slip and which affects the torque of the engine. In synchronous machines, the rotor comprises a rotor that carries an excitation coil in which a direct current flows and generates a static magnetic field. Alternatively, a permanent magnet can be used as the rotor. It is then a permanently excited synchronous machine, which has a higher efficiency due to the powerless excitation and can therefore be more suitable for traction applications. A speed of the rotor can be identical to the speed of an excitation field. The torque can depend on a phase offset, that is to say an angular difference between the stator field and the rotor. To control the power electronics and correspondingly provide electrical power for the stator coils, the speed of the rotor for asynchronous machines and an absolute angular position of the rotor for synchronous machines must be known.

In the context of the present invention, a “sensor” is basically understood to mean any device which is suitable for detecting, for example measuring, at least two measured variables. In the context of the present invention, a system is understood to mean a device consisting of a plurality of components. The sensor system comprises at least two sensors. In particular, the sensor system can be used, for example, to determine the at least one rotational property of the rotating element generate at least one electrical signal corresponding to the at least one rotational property of the rotating element, such as a voltage or a current. Combinations of properties can also be recorded. In particular, the sensor system for determining the at least one rotational property can, for example, also evaluate the at least one electrical signal.

The designations “first sensor” and “second sensor” are to be regarded as pure descriptions without specifying an order or ranking and, for example, without excluding the possibility that several types of first sensors or second sensors or exactly one type can be provided. Additional sensors, for example one or more third sensors, may also be present.

As already stated above, the first sensor of the sensor system can be an incremental angle sensor. For example, the first sensor can be set up to determine at least one incremental angular position, in particular an incremental angle, of the rotating element. The first sensor can be set up to determine a speed and / or a direction of rotation. As already stated above, the second sensor of the sensor system can be an absolute angle sensor. For example, the second sensor can be set up to determine at least one absolute angular position, for example an absolute angle, of the rotating element. In particular, the second sensor can be set up to generate a second signal as a function of an absolute angular position of the rotating element. With regard to the terms “incremental angle” and “absolute angle”, reference can be made to the above explanations. For example, the first sensor can be set up to generate a first signal as a function of a relative angular position of the rotating element.

For example, the first sensor and the second sensor can each comprise at least one sensor selected from the group consisting of: a magnetic sensor and an inductive sensor, in particular an inductive position sensor. An “inductive position sensor” can in principle be understood in the context of the present invention to be any sensor that can generate a signal corresponding to a detected property, in particular a measurement signal, in particular an electrical measurement signal, for example a voltage or a current, wherein the measurement signal is generated is based on a change in magnetic flux.

In particular, the detected property can include a position, for example an angular position. In particular, the inductive position sensor can be an inductive magnetic sensor. However, other configurations are also possible in principle.

In particular, the second sensor can be set up to interact with the magnetic hollow body. For example, the second sensor can in particular interact with the magnetic field of the magnetic hollow body. An interaction of the second sensor with the magnetic field of the magnetic hollow body can be effected, for example, in accordance with a rotation of the magnetic hollow body, in particular in accordance with a rotation of the rotating element. The second sensor can be set up to detect an orientation of a rotating magnetic field.

In particular, the at least two sensors can each be based on at least one different effect. For example, each of the at least two sensors can be based on a different effect. In particular, the different effects on which the at least two sensors are based can be selected from the group consisting of: a Hall effect; an anisotropic magnetoresistive effect (AMR effect); a giant magnetoresistance effect (GMR effect); a magnetic tunnel resistance effect (TMR effect); a colossal magnetoresistive effect (CMR effect).

The sensor system can further comprise at least one evaluation unit. In particular, the evaluation unit can be set up, for example, to evaluate the first signal of the first sensor and the second signal of the second sensor.

Furthermore, the evaluation unit can be set up, for example, to determine the at least one rotational property of the rotating element from the first signal and the second signal. In particular, the evaluation unit can be set up, for example, to determine the at least one rotational property from a combination of the first signal and the second signal.

The sensor system can also have at least one housing. In the context of the present invention, a “housing” is understood in principle to mean any device which preferably gives the sensor system mechanical stability and / or stability against environmental influences. In particular, the device housing can be made entirely or partially of at least one plastic material, for example from an injection molded plastic material.

For example, the at least two sensors can be arranged in the housing. In particular, the sensors can be accommodated, for example, at least partially surrounded by the housing. For example, the sensors can be embedded, for example cast, in a plastic housing. Furthermore, the sensors can for example be in electrical contact with the evaluation unit, for example via electrical conductor tracks, in particular via busbars, for example electrically connected.

In particular, the sensor system can, for example, continue to have at least one connector. In particular, the plug can also be arranged in the housing and / or at least partially surrounded by the housing. For example, the housing can be fixed mechanically, in particular mechanically, by means of the plug, for example in a motor vehicle. Furthermore, the connector of the sensor system can preferably be set up to connect the at least two sensors of the sensor system to a control unit. The plug can in particular be set up to connect the sensor system to a control unit, in particular to a control unit of a motor vehicle. For example, the plug of the sensor system can be set up to enable both mechanical fastening of the housing and electrical contacting, for example a connection, between the at least two sensors and a control unit, in particular a control unit of a motor vehicle. Furthermore, the sensor system can have further components such as, for example, microcontrollers, interference suppression capacitors or the like, which can also be arranged in the housing, for example.

The housing can in particular comprise at least one material selected from the group consisting of: a polymer; a plastic; a thermoplastic; a polybutylene terephthalate (PBT), for example PBT-HR; a polyphenylene sulfide (PPS); a polyamide, for example PA66.

In the context of the present invention, a “magnetic hollow body” is basically understood to mean any element which has a cavity and which can form or generate a magnetic field. In the context of the present invention, a “cavity” is basically understood to mean any region that is completely enclosed in at least one plane. The magnetic hollow body can in particular be a magnetic cylinder, for example a ring. In particular, the magnetic hollow body can have, for example, a permanent or permanent magnet and / or comprise at least one magnetized element. The magnetic hollow body can therefore also be referred to as a magnetic hollow cylinder.

The magnetic hollow body can in particular comprise at least one pair of poles. In the context of the present invention, a “pole pair” is basically understood to mean two magnetic poles that can only occur in pairs and between which a magnetic field is formed. For example, the magnetic hollow body can have at least one magnetic north pole and one magnetic south pole, between which a magnetic field is formed. The magnetic north pole and the magnetic south pole can each have a complementary magnetization. The magnetic hollow body can, for example, also have at least two pole pairs, in particular at least two magnetic north poles and at least two magnetic south poles. The magnetic north pole and the magnetic south pole can each be arranged symmetrically about the axis of rotation. Magnetic north and south poles always alternate along an arbitrary circle within the magnetic hollow body, the center of which lies on the axis of rotation.

For example, the rotating element can comprise a rotor of an electric drive, in which case in particular a number of the pole pairs of the magnetic hollow body can for example also correspond to a number of drive pole pairs of the electric drive. The magnetic north pole and the magnetic south pole can also be referred to as diametrically magnetized regions. The magnetic hollow body can accordingly at least two of the diametrically magnetized areas, i.e. have at least two magnetized regions located on a diameter of the magnetic hollow body.

The magnetic hollow body can comprise at least one hard magnetic material. Furthermore, the magnetic hollow body can comprise at least one ferromagnetic material. In particular, the magnetic hollow body can comprise the hard magnetic material and the ferromagnetic material. The hard magnetic material can be at least partially coated with the ferromagnetic material. The hard magnetic material can comprise an alloy or a ceramic. The alloy or ceramic can have at least one element selected from the group consisting of: iron, cobalt, nickel, ferrite. The hard magnetic material can in particular samarium-cobalt, neodymium-iron-boron and / or magnetized include metallic alloys of iron, nickel and / or aluminum with additions of cobalt, manganese and / or copper. Furthermore, the hard magnetic material can have polymers with magnetizable additives. The hard magnetic material can have a static magnetic field. The ferromagnetic material can be designed to be magnetized and to become a magnet itself in contact with another magnet. The ferromagnetic material comprises a large number of Weiss areas. In an unmagnetized state, a Weiss district can be disordered. In a magnetized state, the Weiss districts can be at least partially aligned. The ferromagnetic material can comprise an alloy. The alloy can have at least one element selected from the group consisting of: iron, cobalt, nickel, ferrite.

The term “interior space” basically designates an area or part of any object which is wholly or partly enclosed by other parts of the object. The object can in particular have one or more walls and the interior can be at least partially formed by the walls. The walls can in particular each have an outwardly facing side and an inwardly facing side. The side facing outwards can face an external environment of the object. The side facing inwards can face the interior. The interior can be open or closed. A closed interior can be enclosed on all sides by one or more walls of the object. An open interior can have at least one area which is directly connected to the external environment of the object. The interior may be the cavity as defined above or may include the cavity. As already explained above, the first sensor and the second sensor are each arranged within the interior, that is to say in the region of the interior. The first sensor and the second sensor can each be arranged in the cavity of the magnetic hollow body.

The terms "axis of rotation" and "axis of rotation" each denote a straight line around which any body rotates or can rotate. In the context of the present invention, the term “axis of rotation” denotes a straight line around which the rotating element is rotatably mounted. In the context of the present invention, the term “axis of rotation” denotes a straight line around which the magnetic hollow body is rotatably mounted. The axis of rotation and the axis of rotation can be identical. However, the axis of rotation and the axis of rotation can also be different from one another. For example, the axis of rotation and the axis of rotation can be arranged offset to one another. In particular, the axis of rotation and the axis of rotation can be arranged parallel to one another.

The first sensor and the second sensor can each be arranged within the interior of the magnetic hollow body. The first sensor and / or the second sensor can be arranged offset to the axis of rotation of the magnetic hollow cylinder. The term “to be arranged offset” can basically include that a center of gravity of a first element is different from a center of gravity of a second element. The first sensor and / or the second sensor can be partially arranged on the axis of rotation. In particular, a center of gravity of the first sensor or a center of gravity of a second sensor can be different from the axis of rotation of the magnetic hollow body. Furthermore, the first sensor and the second sensor can be arranged offset to one another. The first sensor and / or the second sensor can each extend parallel to the axis of rotation.

Alternatively, the first sensor and / or the second sensor can each be arranged transversely, in particular perpendicularly, to the axis of rotation. The first sensor and / or the second sensor can be partially arranged on the axis of rotation. The first sensor and / or the second sensor can each extend parallel to the axis of rotation.

Other arrangements of the first sensor and the second sensor are also conceivable in principle. The first sensor and the second sensor can each be arranged outside the magnetic hollow body, in particular outside the interior of the magnetic hollow body. Alternatively, the first sensor can be arranged outside the magnetic hollow body, in particular outside the interior of the magnetic hollow body, and the second sensor can be arranged inside the interior of the magnetic hollow body. Furthermore, the second sensor can be arranged outside the magnetic hollow body, in particular outside the interior of the magnetic hollow body, and the first sensor can be arranged inside the interior of the magnetic hollow body.

Depending on the type of magnetization of the magnetic hollow body, the at least one sensor located in the interior of the hollow body can be arranged near the inner surface of the hollow body or near the axis of symmetry or rotation of the hollow body. The distance between the hollow body and the sensor (s) arranged near the inside or outside surface of the hollow body can be, for example, in a range from 0.1 mm to 10 mm, in particular from 0.1 mm to 5 mm, preferably from 0.1 mm to 3 mm.

In a further aspect of the present invention, a method for determining at least one rotational property of an element rotating about at least one rotational axis is proposed. The method according to the invention can include the method steps which are described below. The method steps can preferably be carried out in the specified order. One or even several process steps can be carried out simultaneously or overlapping in time. Furthermore, one, several or all of the method steps can be carried out simply or repeatedly. The method can also include further method steps

1. a) Bereitstellen mindestens eines Sensorsystems wie es bereits beschrieben wurde oder im Folgenden noch beschrieben wird;
2. b) Bestimmen mindestens eines ersten Messsignals mittels des ersten Sensors, insbesondere in Abhängigkeit der relativen Winkelposition des magnetischen Hohlkörpers;
3. c) Bestimmen mindestens eines zweiten Messsignals mittels des zweiten Sensors, insbesondere in Abhängigkeit der absoluten Winkelposition des magnetischen Hohlkörpers; und
4. d) Bestimmen der mindestens einen Rotationseigenschaft aus dem ersten Messsignal und dem zweiten Messsignal.

The process steps are:

1. a) providing at least one sensor system as has already been described or will be described below;
2. b) determining at least one first measurement signal by means of the first sensor, in particular as a function of the relative angular position of the magnetic hollow body;
3. c) determining at least one second measurement signal by means of the second sensor, in particular as a function of the absolute angular position of the magnetic hollow body; and
4. d) determining the at least one rotational property from the first measurement signal and the second measurement signal.

The method is carried out using a sensor system according to the present invention, that is to say according to one of the above-mentioned embodiments or according to one of the embodiments described in more detail below. Accordingly, reference can largely be made to the description of the sensor system for definitions and optional configurations. However, other configurations are also possible in principle.

Furthermore, a computer program is proposed within the scope of the present invention, which executes the method according to the invention in one of its configurations when it runs on a computer or computer network. Furthermore, in the context of the present invention, a computer program with program code means is proposed in order to carry out the method according to the invention in one of its configurations when the program is executed on a computer or computer network. In particular, the program code means can be stored on a computer-readable data carrier. In addition, in the context of the present invention, a data carrier is proposed on which a data structure is stored which, after loading into a working and / or main memory of a computer or computer network, can carry out the method according to the invention in one of its configurations. In the context of the present invention, a computer program product with program code means stored on a machine-readable carrier is also proposed in order to carry out the method according to the invention in one of its configurations when the program is executed on a computer or computer network. A computer program product is understood to mean the program as a tradable product. In principle, it can be in any form, for example on paper or a computer-readable data carrier, and can in particular be distributed over a data transmission network. Finally, within the scope of the present invention, a modulated data signal is proposed, which contains instructions that can be executed by a computer system or computer network for executing a method according to one of the described embodiments.

Advantages of the invention

The proposed device and the proposed method have numerous advantages over known devices and methods. A sensor system, in particular a rotor position sensor system, is provided, which can have a combination of an absolute angle sensor and an incremental angle sensor. This places high demands on functional safety, for example on an ASIL D Classification according to ISO26262, achievable. Both sensors are preferably based on different technologies and the signals from both sensors can be checked against each other for plausibility. The absolute angle sensor and the incremental angle sensor can be arranged in the interior of the magnetic hollow body.

In particular, it is possible to provide a functionally safe sensor system that can be used to control electrical machines. For example, a combination of two individual sensors can meet high functional safety requirements. Furthermore, radial tolerances, in particular bearing play, of the sensor wheel can be detected by the proposed device and the proposed method. In particular, the proposed device and the proposed method can, for example, meet higher safety requirements than known devices and methods.

Furthermore, the proposed device and the proposed method can, for example, be significantly less expensive than known devices and methods. In particular, for example, costs incurred during assembly, when changing sensors, for example in the event of repairs, can be significantly reduced in comparison to existing devices and methods, for example by better accessibility. In particular, a position of the sensor system can be easily accessible. For example, the proposed device, in particular the sensor system, can be attached, in particular positioned, to a shaft end. Furthermore, the proposed device may require less space than existing devices. In particular, the proposed device can be, for example, a very small system. For example, the proposed device and the proposed method can have greater flexibility, in particular a simpler and more flexible structure, than conventional devices and methods. In particular, the proposed devices and methods can be used for all types of electrical machines. Furthermore, the proposed device and the proposed method enable a simpler and therefore more robust speed determination in comparison to conventional devices and methods, since in particular complicated calculations, for example differentiation, can be dispensed with, in particular for example when determining the speed by using absolute angle information.

list of figures

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

• 1A und 1B eine schematische Darstellung eines Ausführungsbeispiels eines erfindungsgemäßen Sensorsystems in einer Draufsicht (1A) und in einer Schnittdarstellung (1B);
• 2A und 2B eine schematische Darstellung eines weiteren Ausführungsbeispiels eines erfindungsgemäßen Sensorsystems in einer Draufsicht (2A) und in einer Schnittdarstellung (2B);
• 3A und 3B eine schematische Darstellung eines weiteren Ausführungsbeispiels eines erfindungsgemäßen Sensorsystems in einer Draufsicht (3A) und in einer Schnittdarstellung (3B);
• 4A und 4B eine schematische Darstellung eines ersten Sensors und eines magnetischen Hohlkörpers (4A) und eine bespielhafte Signaldarstellung des ersten Sensors ( 4B);
• 5 eine schematische Darstellung eines Ausführungsbeispiels eines erfindungsgemäßen Sensorsystems in einer Draufsicht;
• 6 eine schematische Darstellung eines weiteren Ausführungsbeispiels eines erfindungsgemäßen Sensorsystems in einer Draufsicht; und
• 7A und 7B eine schematische Darstellung von weiteren Ausführungsbeispielen eines erfindungsgemäßen Sensorsystems in einer Draufsicht.

Show it:

• 1A and 1B a schematic representation of an embodiment of a sensor system according to the invention in a plan view ( 1A) and in a sectional view ( 1B) ;
• 2A and 2 B a schematic representation of a further embodiment of a sensor system according to the invention in a plan view ( 2A) and in a sectional view ( 2 B) ;
• 3A and 3B a schematic representation of a further embodiment of a sensor system according to the invention in a plan view ( 3A) and in a sectional view ( 3B) ;
• 4A and 4B a schematic representation of a first sensor and a magnetic hollow body ( 4A) and an exemplary signal representation of the first sensor ( 4B) ;
• 5 a schematic representation of an embodiment of a sensor system according to the invention in a plan view;
• 6 a schematic representation of another embodiment of a sensor system according to the invention in a plan view; and
• 7A and 7B a schematic representation of further embodiments of a sensor system according to the invention in a plan view.

Embodiments of the invention

1A and 1 B each show a sensor system 110 for determining at least one rotational property of one about at least one axis of rotation 112 rotating element (not shown). In 1A a schematic representation is shown. 1B shows a sectional view.

The sensor system 110 has at least a first sensor 114 and at least a second sensor 116 and a rotating magnetic hollow body which can be connected to the rotating element 118 on. The magnetic hollow body 118 can be an axis of rotation 120 exhibit. The axis of rotation 120 of the magnetic hollow body 118 and the axis of rotation 112 of the rotating element can be identical. The magnetic hollow body 118 closes an interior 122 on. The interior 122 can be used as an open interior 124 be trained. Like for example in 1A illustrated, the magnetic hollow body 118 especially a pair of poles 126 include, in particular a magnetic north pole 128 and a magnetic south pole 130 ,

The first sensor 114 and the second sensor 116 are shown schematically as rectangles. There should be no preferred orientation of the sensors 114 . 116 be shown. Relative placement with respect to the hollow body is crucial. An exact placement can deviate from the shown variants due to rotation and reflection in the room.

The first sensor 114 and the second sensor 116 are in the interior 122 of the magnetic hollow body 118 arranged. The first sensor 114 and the second sensor 116 can be offset to the axis of rotation 120 of the magnetic hollow body 118 be arranged. This is particularly true in 1B represents a section through the in 1A drawn axis A'-A represents. Furthermore, the first sensor 114 and the second sensor 116 also be staggered. The first sensor 114 and the second sensor 116 can each be parallel to the axis of rotation 120 extend.

The first sensor 114 can be an incremental sensor 132 and can be configured to generate a first signal as a function of a relative angular position of the rotating element. The second sensor can be an absolute angle sensor 134 and can be set up to generate a second signal as a function of an absolute angular position of the rotating element. For further details regarding the technical design of the sensors, reference is made to the above description.

2A and 2 B each show another embodiment of a sensor system 110 for determining at least one rotational property of one about at least one axis of rotation 112 rotating element (not shown). In 2A a schematic representation is shown. 2 B shows a sectional view. The sensor system 110 according to the 2A and 2 B corresponds at least largely to the sensor system 110 according to the 1A and 1B , so that at least largely on the description of the 1A and 1B can be referred to above.

The sensor system 110 according to the 2A and 2 B differs from the sensor system 110 according to the 1A and 1B in that the sensor system 110 still at least one housing 136 having. The first sensor 114 and the second sensor 116 can in the housing 136 be arranged as in 2 B shown. The housing 136 can be a plastic case 138 be and the sensors 114 . 116 can in the plastic case 138 embedded, for example poured. Furthermore, the sensors 114 . 116 , for example via electrical conductor tracks (not shown), with electrical contacts 142 , especially a plug 144 be connected. In particular, the connector 114 also in the housing 136 arranged and / or at least partially from the housing 136 be surrounded. The housing 136 can partially in the interior 122 of the magnetic hollow body 18 protrude.

The sensors 114 . 116 can either directly into the plastic housing 138 be cast in 10 and over the electrical conductor tracks with the plug 144 be connected or else be placed on circuit boards, not shown, which can optionally carry further electronic components, such as microcontrollers or interference suppression capacitors for EMC, and then completely or partially in the plastic housing 138 are embedded. With the arrangement shown, it is fundamentally possible to integrate two complete sensor systems, in particular by mirroring the structure on the axis of rotation 120 , Both fully redundant absolute angle and incremental angle signals can then be present.

3A and 3B each show another embodiment of a sensor system 110 for determining at least one rotational property of one about at least one axis of rotation 112 rotating element (not shown). In 3A a schematic representation is shown. 3B shows a sectional view. The sensor system 110 according to the 3A and 3B corresponds at least largely to the sensor system 110 according to the 1A and 1B , so that at least largely on the description of the 1A and 1B can be referred to above.

The sensor system 110 according to the 3A and 3B differs from the sensor system 110 according to the 1A and 1B in the arrangement of the sensors 114 . 116 , The first sensor 114 and / or the second sensor 116 can each cross, in particular perpendicular, to the axis of rotation 120 be arranged. The first sensor 114 and / or the second sensor 116 can partially on the axis of rotation 120 be arranged. The first sensor 114 and / or the second sensor 116 can be parallel to the axis of rotation 120 extend. A measuring range can preferably be adapted to a number of pole pairs. To do this, the number of pole pairs of the magnetic hollow cylinder 118 selected identical to a number of pole pairs of the electrical machine.

4A shows a schematic representation of a first sensor 114 and a magnetic hollow body 118 , 4B shows an exemplary signal representation of the first sensor 114 , The sensor system 110 according to 4A corresponds at least largely to the sensor system 110 according to the 1A and 1B , so that at least largely on the description of the 1A and 1B can be referred to above.

The incremental angle sensor 134 can be a Hall sensor 146 be with three Hall elements 148 , A direction of rotation detection can thus be realized. The Hall element 148 each have lateral extensions in the range of a few mm. A width is preferably b ₁ between a left Hall element 150 and a right Hall element 152 1 mm to 4 mm and corresponds approximately to a width b ₂ of a magnetized area 128 . 130 ,

In 4B is an output O depending on a time t shown. There can be a difference signal of the Hall voltages from the left Hall element 150 and the middle Hall element 154 and 102.2 as A channel and a difference signal of the Hall voltages from the right Hall element 152 and the middle Hall element 154 be referred to as the B channel. Always exceeds the difference of Hall voltages a certain upper threshold, an ASIC, not shown, becomes a logical one 0 output, if the difference falls below a certain lower threshold, the output changes to a logical one 1 , Due to the geometry, the outputs of the A and B channels are out of phase, as in 4B shown. The direction of rotation is detected here, for example, by evaluating the sign of the phase shift.

In principle, a number of the complementarily magnetized areas 128 . 130 can be maximized to ensure high resolution of the incremental angle signal. The size of the areas is limited by the fact that the magnetic contrast, which in particular can correspond to one of the Hall voltage differences, must be sufficiently large. Because the number of complementary magnetized areas 128 . 130 a uniqueness range of the absolute angle sensor 134 is defined, the number of complementarily magnetized regions is preferred 128 . 130 to adapt the number of pole pairs of the machine.

5 shows a further embodiment of a sensor system according to the invention 110 for determining at least one rotational property of one about at least one axis of rotation 112 rotating element (not shown). In 5 a schematic representation is shown. The sensor system 110 according to the 5 corresponds at least largely to the sensor system 110 according to the 1A and 1B , so that at least largely on the description of the 1A and 1B can be referred to above.

The sensor system 110 according to 5 differs from the sensor system 110 according to the 1A and 1B by the arrangement of the sensors 114 . 116 , The first sensor 114 and the second sensor 116 are outside the magnetic hollow body 118 , especially outside of the interior 122 of the magnetic hollow body 118 arranged.

6 shows a further embodiment of a sensor system according to the invention 110 for determining at least one rotational property of one about at least one axis of rotation 112 rotating element (not shown). In 6 a schematic representation is shown. The sensor system 110 according to the 6 corresponds at least largely to the sensor system 110 according to the 1A and 1B , so that at least largely on the description of the 1A and 1B can be referred to above.

The absolute angle sensor 134 basically serves to determine an absolute angle information which is in the angular range of two adjacent, complementarily magnetized regions 128 . 130 is unique. Because the areas 128 . 130 in the sensor system 110 according to the 4A and 4B cover a range of 360 °, the angle measuring range of the absolute angle sensor is also 300 at 360 °. The sensor system 110 according to 6 has two of the magnetic north poles 128 and two of the south magnetic poles 130 on. Accordingly, the uniqueness range for the arrangement in FIG 6 only 180 °.

The term "unambiguously" basically means that something is reversibly clear, possibly also unmistakably clear. For example, a ring magnet with two pairs of pools has a uniqueness range of 180 ° and is not suitable for absolute angle information from 0 to 360 °. For example, a position of 5 ° can be confused with a position of 185 °. a further sensor or a further measure is consequently required for this.

7A and 7B each show a further embodiment of a sensor system according to the invention 110 for determining at least one rotational property of one about at least one axis of rotation 112 rotating element (not shown). In the 7A and 7B a schematic representation is shown in each case. The sensor system 110 according to the 7A and 7B corresponds at least largely to the sensor system 110 according to the 1A and 1B , so that at least largely on the description of the 1A and 1B can be referred to above.

The sensor system 110 according to the 7A and 7B differs from the sensor system 110 according to the 1A and 1B by the arrangement of the sensors 114 . 116 , The first sensor 114 is outside the magnetic hollow body 118 , especially outside of the interior 122 of the magnetic hollow body 118 arranged. The second sensor 116 is inside the interior 122 of the magnetic hollow body.

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included 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.

Patent literature cited

• DE 102013203937 A1 [0002]
• DE 102014220458 A1 [0003]
• EP 0909955 B1 [0004]
• DE 4011503 A1 [0005]

Claims (10)

Sensor system (110) for determining at least one rotational property of an element rotating about at least one axis of rotation (112), the sensor system (110) comprising at least one first sensor (114) and at least one second sensor (116), characterized in that • the sensor system (110) further comprises at least one magnetic hollow body (118) which can be connected to the rotating element, the magnetic hollow body (118) enclosing an interior space (122) and being rotatably mounted about an axis of rotation (120); and • the first sensor (114) and the second sensor (116) are arranged such that the first sensor (114) and the second sensor (116) each have a measurement signal as a function of an interaction with a magnetic field of the magnetic hollow body (118) to generate. Sensor system (110) according to the preceding claim, wherein the first sensor (114) is an incremental angle sensor (132) and is set up to generate a first measurement signal as a function of a relative angular position of the magnetic hollow body (118), the second sensor (116) is an absolute angle sensor (134) and is set up to generate a second measurement signal as a function of an absolute angular position of the magnetic hollow body (118). Sensor system (110) according to one of the preceding claims, wherein the first sensor (114) and the second sensor (116) are each arranged within the interior (122) of the magnetic hollow body (118). Sensor system (110) according to the preceding claim, wherein the first sensor (114) and / or the second sensor (116) are arranged offset to the axis of rotation (120). Sensor system (110) according to one of the preceding claims, wherein the first sensor (114) and / or the second sensor (116) are arranged transversely, in particular perpendicularly, to the axis of rotation (120). Sensor system (110) according to one of the preceding claims, wherein the first sensor (114) and the second sensor (116) are each based on a different effect, the effect being selected from the group consisting of: a Hall effect; an anisotropic magnetoresistive effect (AMR effect); a giant magnetoresistance effect (GMR effect); a magnetic tunnel resistance effect (TMR effect); a colossal magnetoresistive effect (CMR effect). Sensor system (110) according to one of the preceding claims, wherein the magnetic hollow body (118) comprises at least one pole pair (126), the pole pair (126) having at least one magnetic north pole (128) and at least one magnetic south pole (130). Sensor system (110) according to one of the preceding claims, wherein the magnetic hollow cylinder (118) comprises at least one hard magnetic material and at least one ferromagnetic material, the hard magnetic material being at least partially coated with the ferromagnetic material. Sensor system (110) according to one of the preceding claims, wherein the sensor system (110) further comprises at least one housing (136), the housing (136) comprising electrical contacts (142), which are set up, the first sensor (114) and / or to connect the second sensor (116) to a control and evaluation unit, the first sensor (114) and / or the second sensor (116) being accommodated in the housing (136) and by means of electrical conductor tracks with the electrical contacts (142 ) are connected. Method for determining at least one rotational property of an element rotating about at least one axis of rotation (112), the method comprising the following steps: a) providing at least one sensor system (110) according to one of the preceding claims; b) determining at least the first measurement signal by means of the first sensor (114); c) determining at least the second measurement signal by means of the second sensor (116); and d) determining the at least one rotational property from the first measurement signal and the second measurement signal.

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