Sensor arrangement for detecting rotational angles on a rotating component in a vehicle

Abstract

A sensor arrangement is configured to detect rotational angles on a rotating component in a vehicle. The rotating component is coupled to at least one measurement transmitter which generates at least one piece of angle information in connection with at least one measurement sensor in order to determine the rotational angle of the rotating component. A first measurement transmitter and a first measurement sensor form a first angle sensor which generates first angle information that is dependent on the rotational movement of the rotating component, and a second measurement transmitter and a second measurement sensor form a second angle sensor which generates second angle information that is dependent on the rotational movement of the rotating component. A current rotational angle of the rotating component is ascertained from the first angle information and the second angle information. The first angle sensor and the second angle sensor are designed as inductive sensors.

Claims

1. A sensor arrangement for detecting rotational angles on a rotating component in a vehicle, comprising: a common circuit carrier; a first angle sensor configured as an eddy current sensor including (i) a first measuring transducer coupled to the rotating component and having at least one detection range consisting of an electrically conductive material and (ii) a first measuring pickup arranged on the common circuit carrier and having at least two detection coils, an inductance of the at least two detection coils of the first measuring pickup being influenced by a position of the at least one detection range of the first measuring transducer such that the inductance of the at least one detection coils of the first measuring pickup changes periodically in response to rotational movement of the rotating component and is evaluable as a measure of a rotational angle of the rotating component, the first angle sensor configured to generate a first angle information item that is dependent on rotational movement of the rotating component; and a second angle sensor configured as an eddy current sensor including (i) a second measuring transducer coupled to the rotating component and having at least one detection range consisting of an electrically conductive material and (ii) a second measuring pickup arranged on the common circuit carrier and having at least two detection coils, an inductance of the at least two detection coils of the second measuring pickup being influenced by a position of the at least one detection range of the second measuring transducer such that the inductance of the at least two detection coils of the second measuring pickup changes periodically in response to rotational movement of the rotating component and is evaluable as a measure of the rotational angle of the rotating component, the second angle sensor configured to generate a second angle information item that is dependent on the rotational movement of the rotating component, wherein the at least two detection coils of the first measuring pickup are distributed in the common circuit carrier in a plurality of layers and the at least two detection coils of the second measuring pickup are distributed in the common circuit carrier in a plurality of layers, wherein a current rotational angle of the rotating component is determinable from the first angle information item and the second angle information item, wherein the first measuring transducer and the second measuring transducer are respectively configured as an annular disk driven by the rotating component, and wherein the at least one detection range of the first measuring transducer and the at least one detection range of the second measuring transducer are arranged as an annular segment on an outer edge region of the respective annular disk and include the electrically conductive material.

2. The sensor arrangement as claimed in claim 1, wherein the first measuring transducer has four detection ranges and, on an outer circumference, a first annular gear with a first number of teeth, and is fitted onto the rotating component and connected thereto in a rotationally fixed manner.

3. The sensor arrangement as claimed in claim 2, wherein: the second measuring transducer has two detection ranges and, on an outer circumference, a second annular gear which has a second number of teeth and meshes with the first annular gear of the first measuring transducer, and the first number of teeth and the second number of teeth have a predetermined tooth ratio.

4. The sensor arrangement as claimed in claim 1, wherein the at least two detection coils of the first measuring pickup and the at least two detection coils of the second measuring pickup are arranged in the form of annular segments in the common circuit carrier.

5. The sensor arrangement as claimed in claim 3, wherein: the first measuring pickup has three detection coils and generates the first angle information item with a first periodicity, the second measuring pickup has three detection coils and generates the second angle information item with a second periodicity, a periodicity ratio of the first periodicity to the second periodicity is the inverse of the tooth ratio of the first number of teeth to the second number of teeth.

6. The sensor arrangement as claimed in claim 1, wherein the common circuit carrier, the first measuring pickup, and the second measuring pickup are configured such that the first measuring transducer at least partially covers the at least two detection coils of the first measuring pickup with an outer edge region and the second measuring transducer at least partially covers the at least two detection coils of the second measuring pickup with an outer edge region.

7. The sensor arrangement as claimed in claim 1, further comprising: a reference coil arranged on the common circuit carrier away from the first angle sensor and the second angle sensor such that an inductance of the reference coil is independent of rotational movement of the rotating component.

8. The sensor arrangement as claimed in claim 7, further comprising: an evaluation and control unit configured to (i) determine the first angle information item based on the inductance of the reference coil and a periodic change in the inductance of the at least two detection coils of the first measuring pickup, (ii) determine the second angle information item based on the inductance of the reference coil and a periodic change in the inductance of the at least two detection coils of the second measuring pickup, and (iii) determine a rotation angle of the rotating component based on the first angle information item and the second angle information item.

9. A sensor arrangement for detecting rotational angles on a rotating component in a vehicle, comprising: a common circuit carrier; a first angle sensor including (i) a first measuring transducer coupled to the rotating component and having at least one detection range and (ii) a first measuring pickup arranged on the common circuit carrier and having at least one detection coil, an inductance of the at least one detection coil of the first measuring pickup being influenced by a position of the at least one detection range of the first measuring transducer, the first angle sensor configured to generate a first angle information item that is dependent on rotational movement of the rotating component; a second angle sensor including (i) a second measuring transducer coupled to the first measuring transducer and having at least one detection range, and (ii) a second measuring pickup arranged on the common circuit carrier and having at least one detection coil, an inductance of the at least one detection coil of the second measuring pickup being influenced by a position of the at least one detection range of the second measuring transducer, the second angle sensor configured to generate a second angle information item that is dependent on the rotational movement of the rotating component; a reference coil arranged on the common circuit carrier away from the first angle sensor and the second angle sensor such that an inductance of the reference coil is independent of rotational movement of the rotating component; and an evaluation and control unit configured to (i) determine the first angle information item based on the inductance of the reference coil and a periodic change in the inductance of the at least one detection coil of the first measuring pickup, (ii) determine the second angle information item based on the inductance of the reference coil and a periodic change in the inductance of the at least one detection coil of the second measuring pickup, and (iii) determine a rotation angle of the rotating component based on the first angle information item and the second angle information item.

10. The sensor arrangement as claimed in claim 9, wherein: the first measuring transducer and the second measuring transducer are respectively configured as an annular disk driven by the rotating component, and the at least one detection range of the first measuring transducer and the at least one detection range of the second measuring transducer are arranged as an annular segment on an outer edge region of the respective annular disk and include the electrically conductive material.

11. The sensor arrangement as claimed in claim 10, wherein the first measuring transducer has four detection ranges and, on an outer circumference, a first annular gear with a first number of teeth, and is fitted onto the rotating component and connected thereto in a rotationally fixed manner.

12. The sensor arrangement as claimed in claim 11, wherein: the second measuring transducer has two detection ranges and, on an outer circumference, a second annular gear which has a second number of teeth and meshes with the first annular gear of the first measuring transducer, and the first number of teeth and the second number of teeth have a predetermined tooth ratio.

13. The sensor arrangement as claimed in claim 9, wherein the at least one detection coil of the first measuring pickup and the at least one detection coil of the second measuring pickup are arranged in the form of annular segments in the common circuit carrier.

14. The sensor arrangement as claimed in claim 12, wherein: the first measuring pickup has three detection coils and generates the first angle information item with a first periodicity, the second measuring pickup has three detection coils and generates the second angle information item with a second periodicity, a periodicity ratio of the first periodicity to the second periodicity is the inverse of the tooth ratio of the first number of teeth to the second number of teeth.

15. The sensor arrangement as claimed in claim 9, wherein the at least one detection coil of the first measuring pickup and the at least one detection coil of the second measuring pickup are distributed in the common circuit carrier in a plurality of layers.

16. The sensor arrangement as claimed in claim 9, wherein the common circuit carrier, the first measuring pickup, and the second measuring pickup are configured such that the first measuring transducer at least partially covers the at least one detection coil of the first measuring pickup with an outer edge region and the second measuring transducer at least partially covers the at least one detection coil of the second measuring pickup with an outer edge region.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a schematic representation of an exemplary embodiment of a sensor arrangement according to the disclosure.

(2) FIG. 2 shows a schematic characteristic curve diagram of overlap angles of three detection coils of a measuring pickup as a function of the rotational angle of a rotating component.

(3) FIG. 3 shows a more detailed characteristic curve diagram of the overlap angle of the three detection coils of a measuring pickup as a function of the rotational angle of a rotating component of FIG. 2 and an angle information item generated therefrom.

(4) FIG. 4 shows a more detailed characteristic curve diagram of the overlap angle of three detection coils of another measuring pickup as a function of the rotational angle of a rotating component and another angle information item generated therefrom.

(5) FIG. 5 shows a schematic characteristic curve diagram of the angle information items of FIGS. 3 and 4 as a function of the rotational angle of a rotating component.

DETAILED DESCRIPTION

(6) As can be seen in FIG. 1, the exemplary embodiment represented of a sensor arrangement 1 according to the disclosure for detecting rotational angles on a rotating component 3 in a vehicle comprises at least one measuring transducer 20, 30, which is coupled to the rotating component 3 and, in conjunction with at least one measuring pickup 15, 17, generates at least one angle information item .sub.1, .sub.2 for determination of the rotational angle of the rotating component 3. In this case, a first measuring transducer 20 and a first measuring pickup 15 form a first angle sensor 5 that generates a first angle information item .sub.1 dependent on the rotational movement of the rotating component 3. A second measuring transducer 30 and a second measuring pickup 17 form a second angle sensor 7 that generates a second angle information item .sub.2 dependent on the rotational movement of the rotating component 3. A current rotational angle of the rotating component 3 can be determined from the first angle information item .sub.1 and the second angle information item .sub.2. According to the disclosure, the first angle sensor 5 and the second angle sensor 7 are configured as inductive sensors, the measuring transducers 20, 30 respectively having at least one detection range 22, 24, 26, 28, 32, 34 and the measuring pickups 15, 17 respectively having at least one detection coil L.sub.1, L.sub.2, L.sub.3, L.sub.4, L.sub.5, L.sub.6. The at least one detection range 22, 24, 26, 28, 32, 34 of the respective measuring transducer 20, 30 influences the inductance of the at least one corresponding detection coil L.sub.1, L.sub.2, L.sub.3, L.sub.4, L.sub.5, L.sub.6 of the measuring pickup 15, 17 so that the inductance of the at least one detection coil L.sub.1, L.sub.2, L.sub.3, L.sub.4, L.sub.5, L.sub.6 changes periodically because of the rotational movement of the rotating component 3 and can be evaluated as a measure of the rotational angle of the rotating component 3.

(7) Embodiments of the sensor arrangement 1 according to the disclosure may, for example, be used as a steering angle sensor for determining the steering angle of a vehicle or as a rotational angle sensor for determining a pedal position in the vehicle.

(8) As can furthermore be seen in FIG. 1, the measuring transducers 20, 30 are respectively configured as an annular disk which is driven by the rotating component 3. The at least one detection range 22, 24, 26, 28, 32, 34 is arranged in the form of an annular segment on the outer edge region of the annular disk and consists essentially of an electrically conductive material in the exemplary embodiment represented. Thus, the detection ranges 22, 24, 26, 28, 32, 34 may, for example, be configured as metal inlays. As an alternative, the detection ranges 22, 24, 26, 28, 32, 34 may consist essentially of a ferromagnetic material.

(9) In order to facilitate the driving of the measuring transducers 20, 30 configured as an annular disk and the transmission of the rotational movement of the rotating component 3 to the measuring transducers 20, 30, in the exemplary embodiment represented the measuring transducers 20, 30 are configured as gear wheels. Thus, in the exemplary embodiment represented, the first measuring transducer 20 has four detection ranges 22, 24, 26, 28 and, on the outer circumference, a first annular gear (not represented in more detail) which has a first number of teeth. The first measuring transducer 20 is fitted onto the rotating component 3 and is connected thereto in a rotationally fixed manner. In the embodiment as a steering angle sensor, the rotating component 3 represents a steering column of the vehicle. In the exemplary embodiment represented, the second measuring transducer 30 has two detection ranges 32, 34 and, on the outer circumference, a second annular gear which has a second number of teeth and meshes with the first annular gear of the first measuring transducer 20. In this case, the first measuring transducer 20 has a larger diameter than the second measuring transducer 30. The first annular gear therefore has more teeth than the second annular gear, the first number of teeth and the second number of teeth having a predetermined tooth ratio. In order to generate the measurement signals of the two measuring transducers 20, 30 with a similar periodicity, the larger first measuring transducer 20 has more detection ranges than the small second measuring transducer 30. This leads to a smaller periodicity angle of the larger first measuring transducer 20.

(10) In the exemplary embodiment represented, the first annular gear has 69 teeth and the four detection ranges 22, 24, 26, 28 of the first measuring transducer 20, which are configured as annular segments, have a width of about 45 and are distributed uniformly on the outer edge. The small second annular gear has 33 teeth and the two detection ranges 32, 34 of the second measuring transducer 30, which are configured as annular segments, have a width of about 90 and are arranged opposite one another on the outer edge.

(11) As can furthermore be seen from FIG. 1, the at least one detection coil L.sub.1, L.sub.2, L.sub.3 of the first measuring pickup 15 and the at least one detection coil L.sub.4, L.sub.5, L.sub.6 of the second measuring pickup 17 are arranged in the form of annular segments on a common circuit carrier 9. An evaluation and control unit 10 may evaluate the detection coils L.sub.1, L.sub.2, L.sub.3, L.sub.4, L.sub.5, L.sub.6 of the measuring pickups 15, 17 simultaneously or in a predetermined sequence. Furthermore, the evaluation and control unit 10 uses a reference coil L.sub.Ref arranged on the circuit carrier 9 for differential measurements with the detection coils L.sub.1, L.sub.2, L.sub.3, L.sub.4, L.sub.5, L.sub.6 of the measuring pickups 15, 17. The detection coils L.sub.1, L.sub.2, L.sub.3, L.sub.4, L.sub.5, L.sub.6 of the measuring pickups 15, 17 and the reference coil L.sub.Ref may be arranged distributed in the circuit carrier 9 in a plurality of layers, in order to increase the inductance and facilitate the evaluation. The electrical connections between the coils L.sub.1, L.sub.2, L.sub.3, L.sub.4, L.sub.5, L.sub.6, L.sub.Ref and the evaluation and control unit 10 have not been represented for the sake of clarity. In the exemplary embodiment represented, the first measuring pickup 15 has three detection coils L.sub.1, L.sub.2, L.sub.3 and generates the first angle information item with a first periodicity. The second measuring pickup 17 likewise has three detection coils L.sub.4, L.sub.5, L.sub.6 and generates the second angle information item with a second periodicity. The reference coil L.sub.Ref and the detection coils L.sub.1, L.sub.2, L.sub.3, L.sub.4, L.sub.5, L.sub.6 all have similar sizes. For the large first measuring transducer 20, the three detection coils L.sub.1, L.sub.2, L.sub.3 of the first measuring pickup 15 respectively have a width of 45 and a spacing of 15 in the radius of the large first measuring transducer 20. For the small second measuring transducer 30, the three detection coils L.sub.1, L.sub.2, L.sub.3 of the second measuring pickup 17 have a width of 90 and a spacing of 30 in the radius of the small second measuring transducer 30. In principle, the periodicity should be approximately the inverse of the tooth ratio, or the radius ratio. Here, the first measuring transducer 20 and the rotating component 3 have approximately two times the number of teeth and half the periodicity angle.

(12) As can furthermore be seen in FIG. 1, the circuit carrier 9 and the measuring pickups are arranged with respect to one another in such a way that the first measuring transducer 20 at least partially covers the detection coils L.sub.1, L.sub.2, L.sub.3 of the first measuring pickup 15 with its outer edge region and the second measuring transducer 30 at least partially covers the detection coils L.sub.4, L.sub.5, L.sub.6 of the second measuring pickup 17 with its outer edge region. In the exemplary embodiment represented the circuit carrier 9 does not fully enclose the rotating component 3 but has a recess that encloses the rotating component 3 over an angle of about 180. The first measuring pickup 15, arranged at the edge of the recess, therefore likewise covers the first measuring transducer 20 only over an angle of about 180. The second measuring pickup 17, however, covers the second measuring transducer 30 fully, i.e. over an angle of 360.

(13) The inductance of the individual detection coils L.sub.1, L.sub.2, L.sub.3, L.sub.4, L.sub.5, L.sub.6 is dependent on the overlap angle .sub.1, .sub.2, .sub.3, .sub.4, .sub.5, .sub.6 of the respective detection coil L.sub.1, L.sub.2, L.sub.3, L.sub.4, L.sub.5, L.sub.6 with one of the detection ranges 22, 24, 26, 28, 32, 34 of the corresponding measuring transducer 20, 30. The inductance may be determined by the evaluation and control unit 10 by means of a frequency measurement of a tuned circuit which comprises the respective detection coil L.sub.1, L.sub.2, L.sub.3, L.sub.4, L.sub.5, L.sub.6, or by means of a direct inductance measurement using the imaginary component of the impedance of the tuned circuit at a fixed frequency, or by mixing with a reference frequency. The evaluation and control unit 10 then calculates the detected inductance signal back to the overlap angle .sub.1, .sub.2, .sub.3, .sub.4, .sub.5, .sub.6 of the respective detection coil L.sub.1, L.sub.2, L.sub.3, L.sub.4, L.sub.5, L.sub.6 with one of the detection ranges 22, 24, 26, 28, 32, 34.

(14) FIGS. 2 and 3 respectively show the dependency of the overlap angles .sub.4, .sub.5, .sub.6 of the three detection coils L.sub.4, L.sub.5, L.sub.6 of the second measuring pickup 17 as a function of the rotational angle of the rotating component 3. From the represented signal profiles of the three overlap angles .sub.4, .sub.5, .sub.6, the evaluation and control unit 10 can then determine the second angle information item .sub.2 of the small second measuring transducer 30 to within the periodicity of 180. The signal profiles of the three overlap angles .sub.4, .sub.5, .sub.6 are to some extent redundant. From each of the signal profiles, the evaluation and control unit 10 can determine the second angle information item .sub.2, the evaluation and control unit 10 only evaluating the information items from the other two signal profiles additionally in order to determine whether the branch is an increasing branch or a decreasing branch of the signal profile is present. The second angle information item .sub.2 can therefore be determined for each signal profile of the overlap angles .sub.1, .sub.5, .sub.6, the evaluation and control unit 10 preferably calculating an average value and using the calculated average value as the second angle information item .sub.2 for further evaluations and calculations. Possible tilts of the measuring transducers 20, 30 can therefore be compensated for and calculated out.

(15) FIG. 4 shows the dependency of the overlap angles .sub.1, .sub.2, .sub.3 of the three detection coils L.sub.1, L.sub.2, L.sub.3 of the first measuring pickup 15 as a function of the rotational angle of the rotating component 3. In a similar way to the calculation of the second angle information item .sub.2, the evaluation and control unit 10 can determine the first angle information item .sub.1 of the large first measuring transducer 20 to within the periodicity of 90 from the represented signal profiles of the three overlap angles .sub.1, .sub.2, .sub.3.

(16) FIG. 5 shows the two angle information items .sub.1, .sub.2 of FIGS. 3 and 4, from which the revolution of the rotating component 3 is determined, as a function of the rotational angle of the rotating component. If the first angle information item .sub.1 of the large first measuring transducer 20 is multiplied by 2, it can now be seen that the two angle information items .sub.1, .sub.2 only repeat after 2000, about 6 revolutions. The current rotational angle of the rotating component 3 can therefore be determined with a high accuracy.

(17) Embodiments of the sensor arrangement 1 according to the disclosure for detecting rotational angles on a rotating component 3 in a vehicle have the advantage that the circuit carrier 9 does not fully enclose the rotating component 3, and the layout area can therefore be reduced. In order to be able to minimise the area under the small second measuring transducer 30, and therefore also keep the circuit carrier 9 as small as possible, the division ratio between the large first measuring transducer 20 and the small second measuring transducer 30 may be increased from 2 to 3.