SENSOR SYSTEM FOR DETERMINING AT LEAST ONE ROTATIONAL CHARACTERISTIC OF AN ELEMENT ROTATING ABOUT AT LEAST ONE AXIS OF ROTATION

Abstract

A sensor system for determining at least one rotational characteristic of an element rotating about at least one axis of rotation; the sensor system including at least one signal-generating wheel connectable to the rotating element. The signal-generating wheel has a signal-generating wheel profile. The sensor system further includes at least one inductive position sensor; the inductive position sensor having at least one coil set-up that includes at least one operating coil and at least one receiving coil. In addition, the sensor system includes at least one phase detector; the phase detector including at least one magnetic field generator and at least one magnetic sensor element.

Claims

1-14. (canceled)

15. A sensor system for determining at least one rotational characteristic of an element rotating about at least one axis of rotation, the sensor system comprising: at least one signal-generating wheel connectable to the rotating element, the signal-generating wheel having a signal-generating wheel profile; at least one inductive position sensor, the inductive position sensor having at least one coil set-up that includes at least one operating coil and at least one receiving coil; at least one phase detector, the phase detector including at least one magnetic field generator and at least one magnetic sensor element.

16. The sensor system as recited in claim 15, wherein the magnetic sensor element includes at least one element selected from the group made up of a Hall-effect element and a magnetoresistive element.

17. The sensor system as recited in claim 15, wherein the coil set-up is situated on at least one circuit substrate, the circuit substrate is positioned substantially coaxially to the axis of rotation, and the circuit substrate surrounds the signal-generating wheel or a circular segment of the signal-generating wheel in a substantially circular manner.

18. The sensor system as recited in claim 17, wherein the circuit substrate surrounds the signal-generating wheel or a circular segment of the signal-generating wheel in a substantially circular manner, and at at least one angular position, the coil set-up covers at least one profile element and at least one space between two profile elements of the signal-generating wheel.

19. The sensor system as recited in claim 15, wherein the sensor system is configured to measure an inductive coupling and/or a change in an inductive coupling between the operating coil and the receiving coil, and the sensor system is further configured to acquire an electrical measuring signal of the phase detector.

20. The sensor system as recited in claim 15, wherein the sensor system is configured to measure the inductive coupling and/or change in an inductive coupling between the operating coil and the receiving coil produced by a movement and/or a position of the signal-generating wheel, and wherein the sensor system is further configured to acquire an electrical measuring signal of the phase detector produced by the position of the signal-generating wheel.

21. The sensor system as recited in claim 15, wherein the sensor system is configured to determine an angular position of the rotating element from the inductive coupling and/or a change in an inductive coupling between the operating coil and the receiving coil produced by movement of the signal-generating wheel and/or by a position of the signal-generating wheel, and wherein the sensor system is further configured to determine the angular position and/or a rotational speed of the rotating element with the aid of at least one electrical measuring signal of the phase detector produced by the position of the signal-generating wheel.

22. The sensor system as recited in claim 15, wherein the sensor system is configured to allow an angular position of the rotating element to be available upon a switching-on of a voltage supply.

23. The sensor system as recited in claim 15, wherein the at least one receiving coil is made up of at least two consecutive partial windings, and the consecutive partial windings are oriented countercurrently.

24. The sensor system as recited in claim 15, wherein the signal-generating wheel includes at least one profile element.

25. The sensor system as recited in claim 15, wherein the sensor system includes at least two signal-generating wheels.

26. The sensor element as recited in claim 25, wherein the two signal-generating wheels have different signal-generating wheel profiles.

27. A method for determining at least one rotational characteristic of an element rotating about at least one axis of rotation, the method comprising: using at least one signal-generating wheel connectable to the rotating element, the signal-generating wheel having a signal-generating wheel profile; picking up at least one inductive signal with the aid of at least one inductive position sensor, the inductive position sensor having at least one coil set-up that includes at least one operating coil and at least one receiving coil; and picking up at least one phase detector signal with the aid of at least one phase detector, the phase detector including at least one magnetic field generator and at least one magnetic sensor element.

28. The method as recited in claim 27, further comprising: determining an angular position of the rotating element with the aid of the measured inductive coupling and/or a change in an inductive coupling in the coil set-up dependent on a position of the signal-generating wheel and/or a movement of the signal-generating wheel; and determining the angular position and/or a rotational speed of the rotating element with the aid of at least one phase detector signal produced by the position of the signal-generating wheel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Further optional details and features of the present invention are derived from the description below of preferred exemplary embodiments, which are represented schematically in the figures.

[0031] FIG. 1 shows a top view of a schematic representation of an exemplary embodiment of a sensor system according to the present invention.

[0032] FIGS. 2 and 3 show in each instance, a schematic representation of an exemplary embodiment of a coil set-up.

[0033] FIG. 4 shows a schematic view of an exemplary embodiment of a circuit substrate.

[0034] FIGS. 5A, 5B and 6 show schematic views of exemplary embodiments of a signal-generating wheel having a signal-generating wheel profile, as well as of a further signal-generating wheel profile (FIG. 6).

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0035] FIG. 1 shows a top view of a schematic representation of an exemplary embodiment of a sensor system 110 according to the present invention. FIGS. 2 and 3 each show a schematic representation of an exemplary embodiment of a coil set-up 112 for use in sensor system 110 according to FIG. 1. FIG. 4 shows a schematic view of an exemplary embodiment of a circuit substrate 114, which may also be used in sensor system 110 according to FIG. 1. FIGS. 5A, 5B and 6 show schematic exemplary embodiments of a signal-generating wheel 116 having a signal-generating wheel profile 118, which may also be used in sensor system 110 according to FIG. 1. In the following, these figures are explained together.

[0036] Sensor system 110 may be configured, in particular, for use in a motor vehicle. In particular, sensor system 110 may be configured to measure at least one rotational characteristic of a camshaft. For example, sensor system 110 may be configured to measure an angular position of the camshaft and/or a rotational speed of the camshaft. In particular, sensor system 110 may include one or more additional functional elements not shown in the figures, such as electrodes, electrode leads and contacts, a plurality of layers, heating elements or other elements, as shown, for example, in the related art mentioned above.

[0037] Sensor system 110 for determining at least one rotational characteristic of an element rotating about at least one axis of rotation 120 has at least one signal-generating wheel 116 connectable to the rotating element. Signal-generating wheel 116 has a signal-generating wheel profile 118. Sensor system 110 includes at least one inductive position sensor 122. Inductive position sensor 122 includes at least one coil set-up 112, which contains at least one operating coil 124 and at least one receiving coil 126. Sensor system 110 further includes at least one phase detector 128. Phase detector 128 includes at least one magnetic field generator 130 and at least one magnetic sensor element 132.

[0038] FIG. 1 shows, inter alia, the phase detector 128 having magnetic field generator 130 and magnetic sensor element 132. Magnetic field generator 130 may include at least one element selected from the group made up of: a permanent magnet; an electromagnet, for example, a current-carrying coil, in particular, a current-carrying coil having an iron core.

[0039] Magnetic sensor element 132 may include at least one element selected from the group made up of: a Hall-effect element and a magnetoresistive element. Coil set-up 112 may be situated on at least one circuit substrate 114, as can be seen in FIGS. 2 and 3. Circuit substrate 114 may be positioned substantially coaxially to axis of rotation 120, as shown in FIG. 1. Circuit substrate 114 may surround signal-generating wheel 116 or a circular segment of signal-generating wheel 116 in a substantially circular manner, as can be seen in FIG. 1, as well. In particular, at at least one angular position of signal-generating wheel 116, coil set-up 112, in particular, the coil set-up 112 situated on circuit substrate 114, may cover at least one profile element 134 and at least one space 136 between two profile elements 134 of signal-generating wheel 116. In particular, an opening angle of coil set-up 112, shown in FIGS. 1, 2 and 3, may correspond to at least one opening angle of the circular segment of signal-generating wheel 116, likewise shown in FIG. 1, the opening angle including at least one profile element 134 and at least one space 136 between two profile elements 134. Through this, it is possible for a maximum angular resolution to be reproduced.

[0040] Circuit substrate 114 may be designed to be flexible. For example, the circuit substrate may be designed to be flexible and/or curved, in particular, in the shape of a circle or circular segment, as shown in FIG. 4. In particular, circuit substrate 114 may include a flexible material. Circuit substrate 114 may be selected from the group made up of: a circuit board, in particular, a rigid-flex circuit board, for example, a curved rigid-flex circuit board; a rigid circuit board, in particular, a rigid circuit board having notches; a circuit card; a board and a printed circuit, in particular, a printed circuit board (PCB). In addition, circuit substrate 114 may be situated in a housing not shown here, in particular, in an injection-molded housing.

[0041] FIGS. 2 and 3 show, inter alia, two different coil set-ups 112 by way of example. Operating coil 124 may include at least one excitation winding 138. Receiving coil 126 may include at least one receiving winding 140. Receiving winding 140 may include at least two partial windings 142. Partial windings 142 may be oriented countercurrently. In particular, receiving coil 126 may be made up of a receiving winding 140; receiving winding 140 being made up of two partial windings 142; the partial windings 142 being oriented countercurrently. Sensor system 110 may include a plurality of receiving coils 126, for example, a receiving coil system, in particular, a sine/cosine system or a multiphase system. In principle, other coil systems are also conceivable. Sensor system 110 may be configured to model a sine system, a cosine system or a multiphase system for detection. In particular, sensor system 110 may have a quantity of 1 to 100 receiving coils 126, preferably, 2 to 10 receiving coils 126, particularly preferably, 3 receiving coils 126. In particular, receiving coils 126 may each be made up of at least two partial windings 142; in each instance, the partial windings 142 immediately following each other being able to be oriented countercurrently. In particular, receiving coils 126 may exhibit an electrical phase shift with respect to each other. In particular, in each instance, the at least one receiving winding 140 of receiving coils 126, in particular, the partial windings 142 oriented countercurrently, may be staggered according to the electrical phase shift, as shown illustratively in FIG. 3 for a two-phase system that includes a first receiving coil 144 and a second receiving coil 146. In the case of two receiving coils 126, a shift in particular, a geometric twist, of second receiving coil 146 in comparison with first receiving coil 144, in particular, of partial windings 140 of second receiving coil 146 in comparison with partial windings 140 of first receiving coil 144, may be derived from:

=/4(1)

[0042] In a multiphase system including a quantity m of at least 3 receiving coils, the shift may be derived from:

=/m(2)

[0043] In another preferred exemplary embodiment, sensor system 110 may include an operating coil 124 and three receiving coils 126. Receiving coils 126 may each be made up of at least two partial windings 142; the partial windings directly following each other being oriented countercurrently. Receiving coils 126 may exhibit an electrical phase shift of 120 with respect to each other. In particular, partial windings 142 of the three receiving coils 126 may be positioned so as to be staggered in accordance with the electrical phase shift.

[0044] FIGS. 5A and 5B show a top view (FIG. 5A) and a side view (FIG. 5B) of an example of a signal-generating wheel 116 having a signal-generating wheel profile 118. FIG. 6 shows a side view of an alternative embodiment of a signal-generating wheel profile 118. Signal-generating wheel 116 includes at least one profile element 134. While the profile elements 134 in the embodiment of FIG. 5B extend across an entire width of signal-generating wheel 116, the profile elements 134 in the alternative embodiment of FIG. 6 are contoured over the width and form a track profiled in the width. For example, as is apparent in FIG. 6, profile elements 134 each have a rhombic shape. However, other shapes are also conceivable. The at least one profile element 134 may be selected, in particular, from the group made up of: a salient, in particular, a pin-shaped, a tooth-shaped or a serrated salient, for example, a tooth; a notch; a cut-out, for example, a hole; a track profiled in the width of the signal-generating wheel. Signal-generating wheel 116 may include at least one material selected from the group made up of: an electrically conductive material; a ferromagnetic material; a metal. In particular, profile element 134 may include at least one material selected from the group made up of: an electrically conductive material; a ferromagnetic material; a metal. In particular, sensor system 110 may include at least two signal-generating wheels 116. In particular, signal-generating wheels 116 may include different signal-generating wheel profiles 118.

[0045] Sensor system 110 may be configured to measure the inductive coupling and/or a change in the inductive coupling between operating coil 124 and receiving coil 126. In addition, sensor system 110 may be configured to acquire an electrical measuring signal of phase detector 128. The electrical measuring signal may be, in particular, a voltage signal. The electrical measuring signal of phase detector 128 may be, in particular, an electrical measuring signal of magnetic sensor element 132, in particular, of the Hall-effect element. In particular, sensor system 110 may be configured to measure the inductive coupling and/or the change in the inductive coupling between operating coil 124 and receiving coil 126 produced by a movement and/or a position of signal-generating wheel 116. In addition, sensor system 110 may be configured to acquire the electrical measuring signal of phase detector 128 produced by the position of the signal-generating wheel. Furthermore, sensor system 110 may be configured to determine an angular position of the rotating element from the inductive coupling and/or change in the inductive coupling between operating coil 124 and receiving coil 126 produced by the movement and/or the position of signal-generating wheel 116. Moreover, sensor system 110 may be configured to determine the angular position and/or the rotational speed of the rotating element with the aid of at least one electrical measuring signal of phase detector 128 produced by the position of signal-generating wheel 116. In particular, sensor system 110 may be configured to determine the angular position and/or the rotational speed of the rotating element, using at least two electrical measuring signals of phase detector 128 produced by the position of signal-generating wheel 116.

[0046] In particular, sensor system 110 may be configured to transmit the electrical measuring signal of phase detector 128 to a control unit not shown here. In addition, sensor system 110 may include an evaluation unit 148. The evaluation unit may include at least one evaluation circuit. The evaluation unit may be positioned with coil set-up 112 on a common circuit substrate 114, as shown in FIG. 4. The evaluation unit may also be positioned separately from coil set-up 112 on another circuit substrate 114.

[0047] The rotating element has at least one axis of rotation 120. The at least one signal-generating wheel 116 is connectable to the rotating element. Signal-generating wheel 116 may also have an axis of rotation 120. In particular, the rotating element and signal-generating wheel 116 may have a common axis of rotation 120. The rotating element and signal-generating wheel 116 may rotate about common axis of rotation 120. As shown in FIG. 1, during rotation, signal-generating wheel 116 may sweep over coil set-up 112 of inductive position sensor 122; the coil set-up of the inductive position sensor being mounted, for example, concentrically about signal-generating wheel 116 and/or about the circular segment of signal-generating wheel 116. An excitation voltage may be applied to operating coil 124. For example, a voltage of 0.5 to 10 V, preferably, a voltage of 1.5 V, at a frequency of 1 MHz to 10 MHz, particular preferably, 5 MHz, may be applied to operating coil 124. The at least one receiving coil 126 may include at least two partial windings 142 oriented countercurrently. When a voltage is applied to operating coil 124, the voltage induced in receiving coil 126 may also be zero, for example, in the absence of signal-generating wheel 116. While sweeping over coil set-up 112, signal-generating wheel profile 118 may change the inductive coupling between operating coil 124 and receiving coil 126. According to the method of the present invention, in this exemplary embodiment, at least one inductive signal, for example, a voltage signal, is picked up by inductive position sensor 122 in accordance with the inductive coupling and/or the change in the inductive coupling, which may be produced by the position of signal-generating wheel 116 and/or the movement of signal-generating wheel 116. In addition, the method may include determining the angular position of signal-generating wheel 116. The angular position of signal-generating wheel 116 may correspond to an angular position of the rotating element. In particular, sensor system 110 may be configured to allow the angular position of the rotating element to be available upon the switching-on of a voltage supply (true power-on function). Furthermore, during rotation, signal-generating wheel 116 may sweep over magnetic sensor element 132 of phase detector 128. Signal-generating wheel profile 118 may influence the magnetic field generated by magnetic field generator 130. According to the method of the present invention, in this exemplary embodiment, the phase detector signal, in particular, the voltage signal of magnetic sensor element 132, is additionally picked up in accordance with the magnetic field produced by the position of signal-generating wheel 116. Furthermore, the method may include determining the angular position of the signal-generating wheel and/or determining the rotational speed of the rotating element with the aid of the at least one phase detector signal. Moreover, the method may include processing the at least one acquired phase detector signal, using an evaluation circuit not shown here. In addition, the method may include transmitting the at least one acquired phase detector signal to a control unit also not shown in the figures.