Rotation angle sensor
阅读说明:本技术 旋转角度传感器 (Rotation angle sensor ) 是由 F·乌特默伦 A·默茨 于 2018-06-13 设计创作,主要内容包括:旋转角度传感器(10)包括具有发射线圈(20)和至少一个接收线圈(22)的定子元件(12),其中,发射线圈(20)和至少一个接收线圈(22)布置在电路板(18)上。旋转角度传感器(10)包括围绕旋转轴线(A)旋转地受支承的转子元件(14)。旋转角度传感器(10)具有测量范围(β)。在此设置为,至少一个接收线圈(22)在周向方向(U)上基本上完全环绕旋转轴线(A),其中,至少一个接收线圈(22)通过多个相邻的部分绕组(50a-f)形成,其中,每个部分绕组(50a-f)由两个向左弯曲的和两个向右弯曲的圆弧形印制导线(40、42)的区段形成,它们分别具有相同的曲率半径,其中,第一右弯印制导线(40)走向经过三个点,-经过位于第一圆(91)上的第一点(P1);-经过位于第三圆(93)上并且沿周向方向相对于第一点(P1)扭转测量范围(β)的四分之一的第二点(P2),-经过位于第二圆(92)上并且沿周向方向相对于第一点(P1)扭转测量范围(β)的一半的第三点(P3),其中,左弯印制导线(42)由右弯印制导线(40)的镜像得出。(The angle of rotation sensor (10) comprises a stator element (12) having a transmitter coil (20) and at least one receiver coil (22), wherein the transmitter coil (20) and the at least one receiver coil (22) are arranged on a circuit board (18), the angle of rotation sensor (10) comprises a rotor element (14) which is mounted so as to rotate about an axis of rotation (A), the angle of rotation sensor (10) has a measuring range (β), it being provided that the at least one receiver coil (22) substantially completely surrounds the axis of rotation (A) in the circumferential direction (U), wherein the at least one receiver coil (22) is formed by a plurality of adjacent partial windings (50a-f), wherein each partial winding (50a-f) is formed by a section of two left-curved and two right-curved circular-arc-shaped conductor tracks (40, 42) which each have the same radius of curvature, wherein the first right-curved conductor track (40) runs through three points, runs through a first point (P1) on a first circle (91), runs through a third point (93) and runs through a quarter-turn of the second right-curved conductor track (40, via a quarter-turn curve (P) through a second point (5932) which runs through a fourth point (P) on a third circle (3875) and wherein the measuring range (3875) runs through a second point (P) in relation to a measuring range (P) of the left-3) along a measuring range (P3).)
1. A rotation angle sensor (10) for sensing a rotation angle, the rotation angle sensor comprising: a stator element (12) having a transmitting coil (20) and at least two receiving coils (22, 22a, 22b, 22c),
wherein the transmitting coil (20) and the receiving coil (22, 22a, 22b, 22c) are arranged on a circuit board (18);
a rotor element (14) mounted rotatably about a rotational axis (A) with respect to the stator element (12), through which the transmitter coil (20) and the receiver coil (22, 22a, 22b, 22c) are inductively coupled, such that the inductive coupling is dependent on the rotational angle between the stator element (12) and the rotor element (14) and the transmitter coil (20) induces at least two angle-dependent alternating voltages in the receiver coil (22, 22a, 22b, 22 c);
wherein the rotation angle sensor (10) has a measurement range (β) which is obtained by a quotient of 360 DEG and an integer natural number (n),
the receiving coils (22, 22a, 22b, 22c) substantially completely encircle the axis of rotation (A) in a circumferential direction (U),
wherein each receiving coil (22, 22a, 22b, 22c) is formed by a plurality of adjacent partial windings (50a, 50b, 50c, 50d, 50e, 50f), wherein the adjacent partial windings (50a, 50b, 50c, 50d, 50e, 50f) are oppositely oriented with respect to the current flow direction,
wherein each partial winding (50a, 50b, 50c, 50d, 50e, 50f) is formed by at least two segments of a circular-arc-shaped conductor track (42) bent to the left and at least two segments of a circular-arc-shaped conductor track (40) bent to the right with respect to a radial direction (R) extending outward from the axis of rotation (A),
wherein all left-hand curved conductor tracks (42) and all right-hand curved conductor tracks (40) have the same radius of curvature,
wherein all left-hand bent conductor tracks (42) and all right-hand bent conductor tracks (40) extend between two concentric circles around the axis of rotation, a first circle (91) having a first radius (r1) and a second circle (92) having a second radius (r2),
wherein there is a third circle (93) concentric with the first circle (91) and having a third radius (r3) derived from the average of the first radius (r1) and the second radius (r2),
wherein the first right-hand bend printed conductor (40) runs through three points,
-passing through a first point (P1) located on said first circle (91);
-passing a second point (P2) located on the third circle (93) and twisted in a circumferential direction by one quarter of the measurement range (β) with respect to the first point (P1),
-passing through a third point (P3) located on the second circle (92) and twisted in the circumferential direction by half of the measuring range (β) with respect to the first point (P1),
wherein a further right-hand bend printed conductor (40) results from the right-hand bend printed conductor (40) followed by a rotation of half the measuring range (β) in the circumferential direction about the axis of rotation (A),
wherein the left-hand bend conductor tracks (42) result from the mirror images of the right-hand bend conductor tracks (40) on respective radial lines (L) which extend from the axis of rotation (A) through the intersection (S) of the respective right-hand bend conductor tracks (40) with the third circle (93).
2. The rotation angle sensor according to claim 1,
wherein each partial winding (50a, 50b, 50c, 50d, 50e, 50f) is formed by exactly two segments of a circular-arc-shaped conductor track (42) bent to the left and exactly two segments of a circular-arc-shaped conductor track (40) bent to the right, and/or,
wherein the segments of the left-hand curved circular-arc-shaped conductor tracks (42) and the right-hand curved circular-arc-shaped conductor tracks (40) extend, as viewed in the circumferential direction u, substantially over an angular range of at least 20% of the measuring range (β).
3. The rotation angle sensor according to claim 1 or 2,
wherein the circuit board (18) extends between an inner circle (32) having an inner radius (ri) and an outer circle (34) concentric with the inner circle (32) having an outer radius (ra),
wherein the inner circle (32) is concentric with the axis of rotation (A),
wherein the first radius (r1) is at least 1mm and at most 5mm larger than the inner radius (ri), and/or,
wherein the second radius (r2) is at least 1mm smaller and at most 5mm smaller than the outer radius (ra).
4. Rotation angle sensor according to one of the preceding claims,
wherein the rotor element (14) and the receiving coil (22, 22a, 22b, 22c) are designed in such a way that an alternating voltage is induced in the receiving coil (22, 22a, 22b, 22c), the amplitude of which alternating voltage is sinusoidally related to the angle of rotation.
5. Rotation angle sensor according to one of the preceding claims,
wherein all right-hand bent conductor tracks (40) are arranged on a first side (19a) of the circuit board (18) and all left-hand bent conductor tracks (42) are arranged on a second side (19b) of the circuit board (18) facing away from the first side (19 a).
6. The rotation angle sensor (10) according to one of the preceding claims, wherein a plated-through hole (84) is provided on an end of the circular-arc-shaped conductor tracks (40a, 40b), in which the circular-arc-shaped conductor tracks (40, 42) in different planes are connected.
7. Rotation angle sensor (10) according to one of the preceding claims,
wherein the circuit board (18) has a first connection plating through hole (86) and a second connection plating through hole (87),
wherein the two connecting plated-through holes (86, 87) are arranged on the third circle (93) directly adjacent to a virtual intersection point (Px) of the right-hand conductor track (40) and the left-hand conductor track (42),
wherein the right-hand bent conductor track (40) and the left-hand bent conductor track (42) are interrupted in the region of the two connecting feedthrough holes (86, 87), wherein at each of the connecting feedthrough holes (86, 87) a partial section (41) of the right-hand bent conductor track (40) and a partial section (43) of the left-hand bent conductor track (42) which run towards one another from the radially outer side and from the radially inner side, respectively, are electrically conductively connected to one another.
8. Rotation angle sensor (10) according to one of the preceding claims,
wherein the receiving coils (22, 22a, 22b, 22c) are offset in the circumferential direction (U) relative to one another by an angle which is determined by dividing the measuring range (β) by the number (m) of receiving coils (22, 22a, 22b, 22 c).
9. Rotation angle sensor (10) according to one of the preceding claims,
wherein the rotor element (14) has at least one induction section (26) having a different electrical conductivity than an area of the rotor element (14) lying beside it in the circumferential direction (U) about the axis of rotation (A); and/or wherein the at least one induction section (26) is ring-segment shaped.
10. Rotation angle sensor (10) according to claim 9,
wherein the at least one sensor section (26) has a spread angle in the circumferential direction which is greater than half of the measurement range (β) of the rotation angle sensor (10).
11. Rotation angle sensor (10) according to claim 9,
wherein the at least one induction section (26 ') has a plurality of radial slots (58) having a different electrical conductivity than the induction section (26'); and/or wherein the groove (58) is arranged on an edge of the induction section (26') in the circumferential direction; and/or the presence of a gas in the gas,
wherein the grooves (58) are spaced apart in the circumferential direction by an angle which is half as large as the measurement range (β) of the rotation angle sensor (10).
12. Stator element (12) for a rotation angle sensor (10) having a measurement range (β) which is derived from a quotient of 360 ° and an integer natural number (n), the stator element (12) comprising:
a stator element (12) having a transmitting coil (20) and at least two receiving coils (22, 22a, 22b, 22c),
wherein the transmitting coil (20) and the receiving coil (22, 22a, 22b, 22c) are arranged on a circuit board (18);
it is characterized in that the preparation method is characterized in that,
the receiving coils (22, 22a, 22b, 22c) substantially completely encircle the axis of rotation (A) in the circumferential direction (U),
wherein each receiving coil (22, 22a, 22b, 22c) is formed by a plurality of adjacent partial windings (50a, 50b, 50c, 50d, 50e, 50f),
wherein adjacent partial windings (50a, 50b, 50c, 50d, 50e, 50f) are oppositely oriented with respect to the current flow direction,
wherein each partial winding (50a, 50b, 50c, 50d, 50e, 50f) is formed by at least two segments of a circular-arc-shaped conductor track (42) bent to the left and at least two segments of a circular-arc-shaped conductor track (40) bent to the right with respect to a radial direction (R) extending outward from the axis of rotation (A),
wherein all left-hand curved conductor tracks (42) and all right-hand curved conductor tracks (40) have the same radius of curvature,
wherein all left-hand bent conductor tracks (42) and all right-hand bent conductor tracks (40) extend between two concentric circles around the axis of rotation, a first circle (91) having a first radius (r1) and a second circle (92) having a second radius (r2),
wherein there is a third circle (93) concentric with the first circle (91) and having a third radius (r3) derived from the average of the first radius (r1) and the second radius (r2),
wherein the first right-hand bend printed conductor (40) runs through three points,
-passing through a first point (P1) located on said first circle (91);
-passing a second point (P2) located on the third circle (93) and twisted in a circumferential direction by one quarter of the measurement range (β) with respect to the first point (P1),
-passing through a third point (P3) located on the second circle (92) and twisted in the circumferential direction by half of the measuring range (β) with respect to the first point (P1),
wherein a further right-hand bend printed conductor (40) results from the right-hand bend printed conductor (40) followed by a rotation of half the measuring range (β) in the circumferential direction about the axis of rotation (A),
wherein the left-hand bend conductor tracks (42) result from the mirror images of the right-hand bend conductor tracks (40) on respective radial lines (L) which extend from the axis of rotation (A) through the intersection (S) of the respective right-hand bend conductor tracks (40) with the third circle (93).
Technical Field
The invention relates to a rotation angle sensor, by means of which, for example, a rotation angle between a shaft and a further component can be determined. The invention further relates to a stator element for such a rotation angle sensor. Within the framework of the present application, the expression "comprising" is used synonymously with the expression "having".
Background
For measuring the angle of rotation, for example, angle of rotation sensors are known in which a magnet is rotated by a corresponding magnetic field sensor. The measurement of the magnetic field vector allows the angle of rotation to be inferred. Such sensors also react to external magnetic fields, which are caused, for example, by currents generated by adjacently arranged cable wires and which may be very sensitive to interference.
Another type of rotation angle sensor utilizes the eddy current effect. In this case, for example, the metal target is moved over a sensor coil, which is supplied with an alternating voltage and induces eddy currents in the target. This results in a reduction of the inductance of the sensor coil and allows the angle of rotation to be inferred by a change in frequency. For example, the coil is part of a resonant circuit whose resonant frequency shifts when the inductance changes. However, this type of rotation angle sensor can have a high lateral sensitivity with respect to assembly tolerances (mainly the inclination of the target). The generated frequencies can also be disturbed by external electromagnetic fields (Injection Locking), since they are usually operated at frequencies in the range of some tens of MHz.
EP 0909955B 1 shows a rotation angle sensor with a planar conductor wire loop short-circuited on a target, which interacts with an electromagnetic alternating field of an excitation coil.
In this case, for example, a signal is generated which is similar to a rectangular signal dependent on the angle of rotation and which has to be converted into the angle of rotation by the evaluation unit in a complex manner. The angular resolution is limited by the sloping edges of such signals.
Disclosure of Invention
Embodiments of the present invention advantageously make it possible to provide a robust, cost-effective and small-space-demanding rotation angle sensor in which the generated sensor signals can be easily evaluated.
Ideas about embodiments of the present invention can also be considered to be based on ideas and cognition described below.
The invention relates to a rotation angle sensor which can be used in particular in environments with high electromagnetic interference fields. The rotation angle sensor can be used, for example, in or near the motor compartment of the vehicle, for example for determining the position of a throttle, the rotor position of a BLDC motor, the position of an accelerator pedal or the position of a camshaft. The rotation angle sensor described below is cost-effective, requires little installation space and is based on a simple measuring principle.
According to a first aspect of the present invention, a rotation angle sensor for sensing a rotation angle is presented. The rotation angle sensor comprises a stator element having a transmitter coil and at least two receiver coils, wherein the transmitter coil and the receiver coils are arranged on a circuit board. The rotation angle sensor further comprises or has a rotor element which is mounted rotatably about the axis of rotation with respect to the stator element, by means of which rotor element the transmission coil is inductively coupled with the receiving coil, so that the inductive coupling is dependent on the rotation angle between the stator element and the rotor element and the transmission coil induces at least two angularly dependent alternating voltages in the receiving coil. The rotation angle sensor has a measurement range, which is derived from a quotient of 360 ° and an integer natural number. Particularly advantageously, the rotation angle sensor has a measurement range of <360 °.
In this case, it is provided that the receiving coils substantially completely surround the axis of rotation in the circumferential direction, wherein each receiving coil is formed by a plurality of adjacent partial windings, wherein the adjacent partial windings are oriented oppositely with respect to the current flow direction. In this case, each partial winding is formed, with respect to a radial direction extending outward from the axis of rotation, from at least two segments of circular-arc conductor tracks bent to the left and at least two segments of circular-arc conductor tracks bent to the right. All left-hand bend printed conductors and all right-hand bend printed conductors have the same radius of curvature. All left-hand and all right-hand conductor tracks extend between two concentric circles around the axis of rotation, namely a first circle with a first radius and a second circle with a second radius, wherein there is a third circle which is concentric with the first circle and has a third radius which is derived from the average of the first radius and the second radius, wherein the first right-hand conductor track runs through three points: passing through a first point located on a first circle; passing through a second point located on a third circle and twisted in the circumferential direction relative to the first point by a quarter of the measurement range; passing through a third point located on a second circle and twisted in the circumferential direction with respect to the first point by half of the measuring range. The further right-angled conductor track is formed by the following right-angled conductor track by rotating the latter about the axis of rotation by half the measuring range in the circumferential direction. The left-hand bend conductor tracks result from the mirror images of the right-hand bend conductor tracks on respective radial lines extending from the axis of rotation through the intersection of the respective right-hand bend conductor tracks with the third circle.
In this case, the partial winding of the receiver coil can be defined as the part of the receiver coil which is surrounded by the mutually non-intersecting conductor tracks of the receiver coil. The orientation of the partial windings is determined by the current flow through the receiving coil. The oppositely oriented partial windings have respectively an opposite current flow when a current flows through the receiving coil, i.e. in the partial winding having the first orientation the current passes the partial winding in a clockwise direction or to the right and in the partial winding having the second, opposite orientation the current passes the partial winding in a counter-clockwise direction or to the left.
The four sides of such a diamond can be formed, for example, by two partial sections (test ü ck) of two left-hand conductor tracks and two right-hand conductor tracks, respectively.
The current flow directions in at least two sections of the left-hand conductor track forming part of the winding can be opposite to each other, for example. Likewise, the current flow directions in at least two sections of the right-hand bent conductor track forming part of the winding can be opposite to one another.
In this case, the configuration of the partial winding is understood to mean that, when an imaginary straight line starting from the axis of rotation and running in the radial direction passes through the interior of the receiver coil, said straight line intersects the circular-arc-shaped conductor tracks of the receiver coil which are bent to the left and to the right. In this way, it is also possible, for example, for the amplitude of the alternating voltage induced in the receiving coil or the measurement signal to be substantially sinusoidal as a function of the angle of rotation.
With the proposed configuration of the rotation angle sensor, the partial voltages induced by the transmitter coils cancel out in sum (as long as no target or rotor element is present) and are output as an output signal at 0 volts at the receiver coil. By means of this fact, for example, a self-diagnostic function can advantageously be achieved, since the sensor can recognize that the target or the rotor element either does not exist or has at least one electrical interruption. This is particularly advantageous in particular in respect of the keyword "automotive safety integrity level" (ASIL) and the diagnostic functions associated therewith. Furthermore, the external magnetic field, which can in principle be present as a homogeneous field, effectively suppresses the EMV interference effects. The configuration of the stator elements with partial windings substantially completely around the axis of rotation leads to an increased signal-to-noise ratio, a smaller tolerance sensitivity and thus a greater accuracy with respect to stator elements with only a segmented configuration.
The stator element, which can also carry the evaluation unit, can be arranged, for example, opposite the end of a shaft, on which the rotor element is fixed. However, the stator elements may also be arranged around the shaft such that the shaft passes through the stator elements. The rotor element may carry one or more inductive segments which move with the shaft, cover the receiver coil and thereby change the inductivity of the receiver coil or the corresponding inductive coupling between the transmitter coil and the receiver coil. If the transmitting coil is charged with an alternating voltage, an alternating voltage is induced in the receiving coil, the amplitude of which depends on the respective inductive coupling. The evaluation unit can then calculate the angle of rotation signal, for example, from the alternating voltage emitted by the sensor as a measurement signal or its amplitude. In this way, the rotation angle sensor can be realized cost-effectively, since no expensive magnets are required.
The term "the receiving coil substantially completely surrounds the axis of rotation in the circumferential direction" is understood here to mean that the receiving coil completely surrounds the axis of rotation in the circumferential direction by at least 90%, advantageously by at least 95%, and particularly advantageously by at least 99%, i.e. at least approximately covers an angular range of 360 °. Small deviations from a full 360 ° loop can be produced, for example, by connecting wires.
According to one specific embodiment, each partial winding is formed from exactly two segments of circular-arc conductor tracks bent to the left and exactly two segments of circular-arc conductor tracks bent to the right. This advantageously enables a particularly space-saving production of the partial winding and thus of the receiving coil, in particular on only two sides of the circuit board. In addition, in this way, a sinusoidal measurement signal can advantageously be generated, which can be evaluated particularly easily.
Alternatively or additionally, it can be provided that the segments of the left-hand and right-hand curved conductor tracks extend, viewed in the circumferential direction, over substantially at least 20% of the angular range of the measuring range, preferably over at least 23% of the measuring range, for example over 25% of the measuring range. This advantageously results in that the partial winding covers a particularly large area. Furthermore, it is advantageously provided that, viewed in the circumferential direction, virtually no sections on the printed circuit board are configured without partial winding coverage. Therefore, the measurement accuracy can be advantageously improved.
According to one embodiment, the circuit board extends between an inner circle having an inner radius and an outer circle having an outer radius, which is concentric with the inner circle. The inner circle is concentric with the axis of rotation, wherein a first radius of the first circle is at least 1mm and at most 5mm larger than the inner radius.
Alternatively or additionally, it is provided that the second radius of the second circle is at least 1mm smaller and at most 5mm smaller than the outer radius.
The inner radius can be determined, for example, by a passage in the circuit board, through which the shaft can be inserted, for example. The outer radius may be, for example, an outer contour of the circuit board, which may be configured, for example, in a circular or annular manner.
The first radius is at least 1mm and at most 5mm larger than the inner radius, so that on the one hand a sufficient distance is ensured with respect to the through-opening through the circuit board in order to avoid damage to the receiving coil which occurs if tolerances are present in the production. At the same time, the first radius of the first circle is sufficiently small to enable as large a coverage of the measurement field as possible by the receiving coil.
In this case, it can also be provided that the transmitting coil is arranged at least partially between the first circle and the inner circle on the circuit board. In this way, a particularly compact and miniaturized stator element can be constructed.
The second radius of the second circle is at least 1mm smaller and at most 5mm smaller than the outer radius, which advantageously results in a particularly large surface area being available for the receiving coil. This can particularly advantageously improve the signal-to-noise ratio. With a minimum spacing of 1mm relative to the outer radius of the outer circle, damage to the receiving coil due to tolerances during production of the sensor or during handling or assembly is advantageously avoided, since there is a sufficiently large position for the circuit board to be gripped at its outer edge.
Furthermore, advantageously, the transmitting coil may be arranged at least partially in a region between the outer circle and the second circle. In this way, a particularly large transmitting coil with a large radius can be realized.
According to one embodiment, the rotor element and the receiving coil are designed such that an alternating voltage is induced in the receiving coil, the amplitude of which is sinusoidally related to the angle of rotation.
In other words, the measurement signal provided by the receiver coil, i.e. the amplitude of the alternating voltage induced in the receiver coil, is sinusoidal or a sinusoidal function dependent on the angle of rotation due to the geometry of the receiver coil and the rotor element.
It is understood that the sinusoidal measurement signal may be a signal that deviates less than 5% or less than 1% from a pure sinusoidal function.
A particularly simple evaluation can be achieved by sinusoidal amplitudes, for example, without expensive electronic components or software having high robustness. Furthermore, when there are at least two receiving coils, a signal reliability test can be achieved by using a trigonometric rule.
According to an embodiment of the invention, the at least two receiving coils are formed in (only) two planes of the circuit board, i.e. in particular on the outer face.
In this case, it can be provided, for example, that all right-angled conductor tracks are arranged on a first side of the printed circuit board and all left-angled conductor tracks are arranged on a second side of the conductor tracks facing away from the first side.
In this way, the circuit board can be manufactured cost-effectively. A multi-layer circuit board, in particular a circuit board having more than two layers, is not required. The production can thereby be significantly simplified and more cost-effective to implement.
This can be done by: the ends of the circular-arc-shaped conductor tracks are provided with plated-through holes, in which the circular-arc-shaped conductor tracks in different planes are connected. The circular-arc-shaped conductor tracks of the receiver coils may in particular be arranged alternately in opposite planes of the circuit board.
This advantageously results in that the stator element with a circuit board having only 2 layers can be constructed, for example, from FR4 material or better.
According to one embodiment, plated-through holes are provided at the ends of the circular-arc-shaped conductor tracks, in which the circular-arc-shaped conductor tracks in the different planes are connected. This advantageously results in that the partial windings of the receiving coil do not intersect on the same side of the circuit board and therefore do not lead to a short circuit. By this configuration, the receiving coil can be equipped with a high density of partial windings, thereby improving the measurement signal.
According to one specific embodiment, the circuit board has a first connection feedthrough and a second connection feedthrough, wherein the two connection feedthroughs are arranged directly adjacent to a virtual intersection of the right-hand conductor track and the left-hand conductor track on a third circle. The right-hand and left-hand conductor tracks are interrupted in the region of the two connecting plated-through holes. At each of the connection plating through holes, a partial section of the right-angled conductor track and a partial section of the left-angled conductor track, which run from the radially outer side and from the radially inner side toward one another, are electrically conductively connected to one another.
This advantageously results in that adjacent partial windings of the receiving coil can be configured in a particularly simple and space-saving manner with an orientation opposite to the current flow direction. By means of this configuration, a polarity reversal of the current flow direction at a position radially outside the second circle or radially between the axis of rotation and the first circle can be eliminated, as a result of which it is possible to avoid the formation of additional conductor track sections, which can generate additional signal magnitudes.
According to one embodiment, the receiver coils are offset in the circumferential direction relative to one another by an angle which is determined by dividing the measurement range by the number of receiver coils.
The number of receiving coils is understood here to be the total number of receiving coils of the measuring system. If, for example, two redundant measuring systems are arranged on the same circuit board, each measuring system having three receiving coils, the number of receiving coils corresponds to m 3.
By means of the proposed angular shift, a particularly well analyzable processed signal is provided, thereby improving the accuracy of the rotation angle sensing.
In this way, each receiving coil produces a maximally different measuring signal. This advantageously improves the accuracy of the angle determination.
For example, two or three receiver coils, which are offset at a defined angle relative to one another, for example in the circumferential direction, and which provide an angularly offset measurement signal, can be arranged on the stator element. The sinusoidal signals as measurement signals can be evaluated particularly advantageously in two or three receiver coils, since an inverse transformation is possible. This may be an anti-tangential transformation in two receiver coils (i.e. a two-phase system) or a Clarke transformation in three receiver coils (i.e. a three-phase system). By means of the inverse transformation, deviations, which occur, for example, as a result of mechanical tolerances, can also be easily subtracted from the measurement signal.
It is also possible for two redundant receiver coil systems or measuring systems (for example, consisting of two or three receiver coils each) to be present on the stator element. In this case, the measurement signals of the individual receiver coil systems or measurement systems can be evaluated in the manner mentioned above. This also enables the angle of rotation to be determined in the event of a system failure, which can improve safety in critical systems.
According to an embodiment of the invention, the rotor element has at least one induction section having a different electrical conductivity than a region of the rotor element lying aside in the circumferential direction about the axis of rotation. The induction section may be, for example, a metal section (with high electrical conductivity) which is fixed to a non-metallic part of the rotor element, a metal projection on the rotor element, but also a slot (with low electrical conductivity) in the metallic rotor element.
The at least one inductive segment may be, for example, ring segment shaped. It is possible for the rotor element to have a plurality of identically shaped induction sections. This makes it possible to provide a particularly simple and cost-effective design of the rotor element, which may also be referred to as a target. In addition, an imbalance is not produced when the target has a high rotational speed.
According to an embodiment of the invention, the at least one sensor segment has a spread angle (i.e. the maximum angle spread by the sensor segment) in the circumferential direction, which is half the measurement range of the rotation angle sensor. The partial windings of the receiver coil can also have such a flare angle. In this way, a maximum variation of the measurement signal over the measurement range can be achieved. Improved accuracy and a more robust signal may thereby advantageously be achieved.
According to an embodiment of the invention, the at least one induction section has a plurality of radial slots, said slots having a different electrical conductivity than the induction section. The slots may be arranged on the edge of the sensor section in the circumferential direction, wherein the sensor section may have a flare angle greater than half the measurement range. The slots may be spaced apart in the circumferential direction by an angle which is half the measuring range of the rotation angle sensor. The induction section may be divided into one large sub-section and a smaller sub-section spaced apart from it in the circumferential direction.
The measurement signal can be shaped by the slots, since the small subsegments can influence the inductive coupling of the partial windings arranged adjacent to the partial windings that are covered by the large subsegments. The measurement signals, which are based on the receiver coils also having a small deviation from the sinusoidal function, can be influenced in particular by the induction section in such a way that the deviation becomes smaller.
According to a second aspect of the invention, a stator element for a rotation angle sensor is proposed, which stator element is described above and below. A stator element for a rotation angle sensor has a measurement range which is derived from the quotient of 360 DEG and an integer natural number, comprising a stator element having a transmitter coil and at least two receiver coils. The transmitting coil and the receiving coil are arranged on a circuit board. The receiving coil substantially completely surrounds the axis of rotation in the circumferential direction. Each receiving coil is formed by a plurality of adjacent partial windings. Adjacent partial windings are oriented oppositely with respect to the current flow direction, wherein each partial winding is formed, with respect to a radial direction extending outward from the axis of rotation, by at least two segments of a circular-arc-shaped conductor track bent to the left and at least two segments of a circular-arc-shaped conductor track bent to the right. All left-hand bend printed conductors and all right-hand bend printed conductors have the same radius of curvature. All left-hand bend conductor tracks and all right-hand bend conductor tracks extend between two circles concentric about the axis of rotation, a first circle having a first radius and a second circle having a second radius. There is a third circle concentric with the first circle and having a third radius derived from an average of the first radius and the second radius. The first right-hand bend printed conductor runs through three points: passing through a first point located on a first circle; passing through a second point located on a third circle and twisted in the circumferential direction relative to the first point by a quarter of the measurement range; passing through a third point located on a second circle and twisted in the circumferential direction with respect to the first point by half of the measuring range. The further right-angled conductor track is formed by the following right-angled conductor track by rotating the latter about the axis of rotation by half the measuring range in the circumferential direction. The left-hand bend conductor tracks result from the mirror images of the right-hand bend conductor tracks on respective radial lines extending from the axis of rotation through the intersection of the respective right-hand bend conductor tracks with the third circle.
A particularly cost-effective, highly precise and easily producible rotation angle sensor can be produced advantageously by a stator element of this type.
It is understood that the right-hand bend and the left-hand bend may be formed by a plurality of partial conductor tracks directly adjacent to one another. The partial winding may be formed, for example, from a total of four partial sections, two partial sections each belonging to two left-hand conductor tracks and two partial sections each belonging to two right-hand conductor tracks.
The number of partial windings may correspond to twice the integral natural number by which the measuring range is defined.
It may be provided that the transmitter coil is arranged concentrically to the axis of rotation.
Drawings
Embodiments of the invention are described below with reference to the drawings, wherein the drawings and the description are not to be considered as limiting the invention.
Fig. 1 schematically shows a longitudinal section of a rotation angle sensor according to an embodiment of the invention.
Fig. 2 shows a schematic top view of a stator element for the rotational angle sensor in fig. 1, wherein only the first receiving coil is shown.
Fig. 3 shows an enlarged portion of fig. 2.
Fig. 4 shows a schematic top view of the stator element of fig. 2, in which three receiving coils of the measuring system are shown.
Fig. 5 shows a schematic top view of a rotor element for the rotation angle sensor of fig. 1.
Fig. 6 shows a schematic top view of an alternative induction section for the rotor element of fig. 5.
Fig. 7 shows a graph of a measurement signal generated by a rotation angle sensor according to an embodiment of the invention.
The figures are schematic only and not to scale. The same reference numerals indicate features which are the same or functionally equivalent in the drawings.
Detailed Description
Fig. 1 shows a
The
The
Fig. 2 shows the
Here, the
In the present example, the
The current flow direction of each partial winding is shown by the ring arrows. In the exemplary embodiment shown, each partial winding is formed, with respect to a radial direction R extending outward from the axis of rotation a, from two partial sections of two circular-arc conductor tracks 42 bent to the left and two partial sections of two circular-arc conductor tracks 40 bent to the right. Arrows are drawn on some of these conductor tracks, which arrows indicate the direction of current flow.
Adjacent partial windings have the same faces in a pair-wise manner: in the example shown, the surfaces of the
On this basis, the
All left-bent conductor tracks 42 and all right-bent conductor tracks 40 have the same radius of curvature, wherein all left-bent conductor tracks 42 and all right-bent conductor tracks 40 extend between two concentric circles around the axis of rotation a, namely a
The radial direction R is illustrated by way of example in fig. 1, which intersects a right-hand circular-arc-shaped
The further right-hand
At the ends of the circular-arc-shaped conductor tracks 40, 42, plated-through
In the present case, the measurement range is β ° -120 °, so that six
In order to achieve a reversal of the orientation of the adjacent
The virtual intersection point Px is not a real intersection point of the conductor tracks 40, 42, since these run in different planes of the
Fig. 3 shows an enlarged portion of fig. 2 in the region of the two connecting plated-through
Fig. 4 shows a
The receiving
For example, the transmitting
As indicated above, the measuring range β of the angle of
The
The receiving
The second and third receiving coils 22b, 22c are of substantially the same design as the
The intersection of the circular-arc-shaped conductor tracks 40, 42 of the first, second and
The intersections of the circular-arc-shaped conductor tracks 40, 42 are spaced apart by the same angle in the circumferential direction, the angle between the intersections being β/4 (here 30 °). thus, the intersections of the circular-arc-shaped conductor tracks 40, 42 of the
In general, the required geometric torsion ξ of the receiver coils 22 is determined from the measuring range β and the number m of receiver coils according to the formula ξ ═ β/m, m ≧ 3, or ξ ═ β/(2m), m ═ 2.
In the exemplary embodiment shown, a 40 ° geometric rotation ξ of the three
It is possible for the three receiving
This can be achieved by: all right-hand circular-arc-shaped conductor tracks 40 of the three
In order to achieve opposite current flow directions of adjacent partial windings, in the illustrated embodiment, two connection-plated through
Fig. 5 shows a schematic top view of the
The
The
Preferably, straight or linear radial dividing lines are used, thereby ensuring particularly simple and production-safe manufacture.
The inner radius rit and the outer radius rat of the
Fig. 6 shows an alternative embodiment of a sensor segment 26' constructed from a plurality of
The sub-segments 56a, 56b are separated from one another by a slot 58 (e.g., a milled portion) having a different conductivity than the sub-segments 56a, 56 b. In this way, the sinusoidal shape of the measurement signal can be improved.
The width of each of the
Fig. 7 shows a diagram with three sinusoidal measurement signals 60 which can be emitted by the
Due to the different lengths of the supply lines, the positioning of the conductor tracks in different planes of the printed
This deviation can be deducted particularly easily from the
For example, three sinusoidal measurement signals 60 with a typical electrical phase difference of 120 ° are generated in the three
It is also possible for the
In general, at least two receiving
For reasons of redundancy, the
Finally it is pointed out that concepts such as "having", "comprising", etc. do not exclude other elements or steps and that concepts such as "a" or "an" do not exclude a plurality. Reference signs in the claims shall not be construed as limiting.
- 上一篇:一种医用注射器针头装配设备
- 下一篇:编码器