CN105222817B

CN105222817B - Sensor device for determining at least one rotation characteristic of a rotating element

Info

Publication number: CN105222817B
Application number: CN201510349773.5A
Authority: CN
Inventors: F·西古拉; K·莱
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2014-06-26
Filing date: 2015-06-23
Publication date: 2020-05-22
Anticipated expiration: 2035-06-23
Also published as: KR20160001677A; DE102014212262A1; CN105222817A

Abstract

A sensor device (10) for determining at least one rotational characteristic of a rotating element (12) is proposed. The sensor device (10) comprises at least one transmitter (14) and a transmitter wheel (16). The transmitter wheel (16) has teeth (18), tooth gaps (20) between the teeth (18), and at least one transmitter wheel gap (26). The transmitter (14) is designed to generate an output signal (46). The output signal (46) comprises at least one first value (52) assigned to one of the teeth (18) or a second value (54) assigned to the tooth gap (20). The at least one transmitter wheel gap (26) is designed in such a way that the output signal (46) comprises a third value (56) which is assigned to the transmitter wheel gap (26) and which differs in size from the second value (54).

Description

Sensor device for determining at least one rotation characteristic of a rotating element

Background

Various sensors are known from the prior art which detect at least one rotational characteristic of a rotating element. Herein, rotational characteristics are generally understood to be characteristics that describe, at least in part, the rotation of a rotating element. For example, angular velocity, rotational speed, angular acceleration, rotational angle, angular position or other characteristics may be used, which may characterize a continuous or discontinuous, uniform or non-uniform rotation or rotation of the rotating element. From Konrad Reif (Hrsg.): examples of such sensors are known from Sensoren im Krafffahrzeug, first edition 2010, pages 63-73 and pages 120-129. The particular emphasis of the invention is on the detection of the number of revolutions of the crankshaft or camshaft, to which, however, the invention is not limited in principle.

In the control of internal combustion engines, it is known, for example, to use incremental transmitters (incremental sensors) on the crankshaft and/or camshaft. The encoder disk usually has incremental markings which comprise teeth and tooth gaps, which interact with signals of the crankshaft or camshaft.

The transmitter system utilizes a non-uniform arrangement of incremental marks. A typical realization is a transmitter wheel with 60 minus 2 teeth, i.e. 58 teeth, and a transmitter wheel gap of two teeth.

Despite the advantages brought about by the transmitter described above, it still has the potential for improvement. The purpose of the transmitter backlash is to synchronize the motor control with the crankshaft position. The motor control device continuously measures the time between two tooth flanks of the passing sensor. Here, the transmitter backlash is detected by: the time between a tooth arranged in front of the transmitter wheel gap and a tooth arranged behind the transmitter wheel gap is greater than the time between other adjacent teeth. In other words, the time interval of the tooth/transmitter wheel gap pairs is greater than the time interval of the tooth/tooth gap pairs. However, if the half time interval of a tooth/transmitter wheel gap pair is greater than the time interval of a tooth/transmitter wheel gap pair, the motor control resynchronizes the wrong angle or, if it has already been synchronized, its synchronization is lost, because the motor control no longer ensures the correct position.

Disclosure of Invention

A corresponding object of the invention is to provide a sensor device for determining at least one rotational characteristic of a rotating element, which sensor device avoids the disadvantages described above at least as far as possible and is suitable in particular for the safe and reliable detection of backlash in a encoder wheel even under difficult edge conditions.

The sensor device according to the invention for determining at least one rotation characteristic of a rotating element comprises at least one transmitter and a transmitter wheel. The transmitter wheel has teeth, tooth gaps between the teeth, and at least one transmitter wheel gap. The transmitter (Geber) is designed to generate an output signal. The output signal comprises at least one first value assigned to one of the teeth or a second value assigned to the tooth gap. The at least one transmitter wheel gap is designed such that the output signal comprises a third value assigned to the transmitter wheel gap and whose magnitude differs from the second value.

The third value may in particular be smaller than the second value. Here, the second value may be smaller than the first value. The transmitter wheel gap preferably has a recess in the transmitter wheel. The recess may have a depth of 0.1mm to 1.0 mm. The output signal may be an analog output signal. Alternatively, the output signal may be a digital output signal, in particular a rectangular signal. The output signal may in particular be an electrical output signal. The output signal is, for example, a voltage. The transmitter may have at least one transmitter element for providing an output signal. The transmitter element may be a hall element. Alternatively, the transmitter may be an inductive transmitter. Within the scope of the invention, the rotation characteristic may be the number of revolutions of the rotating element.

Furthermore, the sensor device may comprise at least one incremental bearing connectable to the rotary element. The at least one incremental bearing may be a gear. The gear may be at least partially composed of a ferromagnetic material. Alternatively or additionally, the at least one incremental bearing may be a magnetic multipole wheel. The multipole wheel can be formed, for example, by permanent magnet particles contained in plastic by means of a polarization alternating from region to region. It can also be provided that the at least one incremental bearing has a permanent-magnetic region and that the incremental bearing is provided for forming eddy currents. In this case, the increment support in the form of a pole wheel described above is preferably used.

Within the scope of the invention, an incremental bearing is understood to be a bearing which can be connected to a rotary element or to a rotary element. The carrier part can be designed, for example, in the form of a transmitter wheel. In incremental measuring methods, an incremental carrier is usually used. A frequently used measuring method in revolution transmitters is the incremental counting method, in which the change in value per time unit is measured by counting of individual values (also referred to as incremental values) and different rotation characteristics, for example the number of revolutions or one of the other characteristics described above, are inferred therefrom. The increment carrier generally has value transmitters arranged periodically along the path, which can each individually detect and each trigger an increase or a decrease in the counter value by one increment. The incremental carrier can consist, for example, of a toothed wheel coordinated with a corresponding magnetic transmitter, which toothed wheel consists of a magnetizable material, which produces a detectable event in the region of each tooth and in the region of each gap arranged between two teeth by different influences of the magnetic field as long as the material moves through an external magnetic field. It is also conceivable for the incremental carrier to be designed in the form of a multi-pole wheel, which is usually designed by means of alternating or alternating magnetic polarization in the sequence of the permanent magnet regions. In this case, the multipole wheel can generate a plurality of detectable magnetic events by the formation of a plurality of individual magnetic field regions (by interference with an external magnetic field, for example by superposition), i.e. by measurement of the change in the external magnetic field, or by direct measurement of a plurality of magnetic field regions between two adjacent permanent magnet regions.

The sensor device may comprise at least one analysis processing unit. The at least one evaluation unit can be provided for evaluating the output signal. The evaluation of the output signal is generally understood here to mean any arbitrary processing step which is carried out on the output signal for obtaining information about the rotational behavior of the rotating element. In this case, for example, it can be provided that, when the absolute angular position is the rotation characteristic to be detected, the evaluation unit evaluates the output signal at least partially, but preferably completely, and provides the obtained information about the rotation characteristic of the rotating element in the form of data signals, for example, of a motor control device, in particular of a motor control device, which does not belong to the sensor device. In this case, the motor control device receives information about the rotation characteristics, for example from the evaluation unit, and has to compare and/or check the rotation characteristics on the basis of said information with regard to the accuracy of the respective information about the rotation characteristics.

Furthermore, it is possible to implement the entire evaluation of the individual output signals of the sensor device in the sensor device by means of evaluation electronics which are substantially matched to the sensor device in such a way that the acquisition of information about the rotational behavior can be carried out in approximately real time.

A further advantageous embodiment of the sensor device with at least one evaluation unit is that the at least one evaluation unit has a signal output. The at least one evaluation unit can be provided to provide, at its output, only one of the evaluated sensor signals as a function of the number of revolutions of the rotating element. The rotation characteristic may be, in particular, the number of revolutions.

Drawings

Further optional details and features of the invention result from the description of preferred embodiments, which is schematically illustrated in the drawings.

The figures show:

FIG. 1: a schematic view of a sensor device according to the invention;

FIG. 2: an output signal provided by the sensor device.

Detailed Description

Fig. 1 shows a schematic representation of the structure of a sensor device 10 according to the invention for determining at least one rotation characteristic of a rotating element 12. In the embodiment shown, the rotation characteristic relates to the number of revolutions of the rotating element 12. However, it is understood that other rotational characteristics, such as angular velocity and angular acceleration, can also be detected by means of the sensor device 10.

The rotating element 12 is, for example, a crankshaft of an internal combustion engine. The sensor device 10 includes at least one transmitter 14 and a transmitter wheel 16. The transmitter wheel 16 is connected to the rotating element 12. The transmitter wheel 16 has teeth 18 and tooth spaces 20 between the teeth 18. The transmitter wheel 16 has, for example, a number 58 of teeth 18. The width 22 of the tooth space 20 may be the same as the width 24 of the tooth 18. The transmitter wheel 16 also has at least one transmitter wheel gap 26. The transmitter wheel gap 26 is configured such that it is different from the tooth gap 20, as described in more detail below. The transmitter wheel gap 26 has a width 28 that is greater than the width 22 of the tooth gap 22 or the width 24 of the tooth 18. The transmitter wheel gap 26 has, for example, a width 28 that is four times as large as the width 22 of the tooth gap 22 or the width 24 of the tooth 18. Thus, the transmitter wheel 16 has a number of 60 minus 2 teeth 18, i.e. 58 teeth, and has a transmitter wheel gap 26 of two teeth 18 with corresponding wheel gaps 20. Furthermore, the encoder wheel gap 26 has a recess 30 formed in the encoder wheel 16. The recess 30 may have a depth 32 of 0.1mm to 1.0mm, for example 0.5 mm. Thus, the distance 34 from the tooth crest 36 to the surface 38 of the tooth space 20 is less than the distance 40 from the tooth crest 36 to the surface 42 of the recess 30. In other words, the surface 42 of the recess 30 is spaced further from the tooth crest 36 than the surface 38 of the tooth clearance 20. It is understood, however, that the recess 30 may have a greater depth 32 depending on the respective application. Thus, to improve the zonal dispenser wheel gap 26 and the tooth gap 22, the recess 30 may, for example, have a depth 32 greater than 1.0mm, such as 1.5mm, 2.0mm, or 5.0 mm. The transmitter 14 has at least one transmitter element 44. The transmitter element 44 is for example a hall element. The transmitter 14 is configured to generate an output signal, as described in more detail below.

Fig. 2 shows an output signal 46 provided by the sensor device 10 or the transmitter 14. The output signal 46 varies depending on whether the tooth 18, the tooth gap 20, or the transmitter wheel gap 26 passes by the transmitter 14. The output signal can be an analog output signal 46, as shown in fig. 2. It should be understood that a digital output signal, which may be present, for example, as a rectangular signal, may be provided from the transmitter element 44. The output signal 46 is preferably an electrical output signal 48, such as a voltage 50, the variation of which is shown in fig. 2.

The output signal 46 comprises at least one first value 52 assigned to one of the teeth 18 or a second value 54 assigned to the tooth gap 20. Thus, output signal 46 includes a first value 52 as tooth 18 passes transmitter 14 or output signal 46 includes a second value 54 as tooth gap 20 passes transmitter 14. The second value 54 is in particular smaller than the first value 52. That is, when the tooth gap 20 passes over the transmitter element, the transmitter element 44 provides a smaller voltage 50 than when the tooth 18 passes over the transmitter element. Transmitter wheel gap 26 is configured conditionally by recess 30 such that output signal 46 comprises a third value 56, which is assigned to transmitter wheel gap 26 and which differs in magnitude from second value 54. The third value 56 is less than the second value 54. That is, when the transmitter wheel gap 26 with the recess 30 passes the transmitter element, the transmitter element 44 provides a smaller voltage 50 than when the wheel gap 20 passes the transmitter element. The smaller voltage value enables a univocal identification of the transmitter wheel gap 26.

Claims

1. A sensor device (10) for determining at least one rotational characteristic of a rotating element (12), comprising at least one transmitter (14) and a transmitter wheel (16), wherein the transmitter wheel (16) has teeth (18), tooth gaps (20) between the teeth (18) and at least one transmitter wheel gap (26), wherein the transmitter (14) is designed to generate an output signal (46), wherein the output signal (46) comprises at least one first value (52) assigned to one of the teeth (18) or a second value (54) assigned to the tooth gap (20),

it is characterized in that the preparation method is characterized in that,

the at least one transmitter wheel gap (26) is designed in such a way that the output signal (46) comprises a third value (56) which is assigned to the transmitter wheel gap (26) and which differs in magnitude from the second value (54), wherein the transmitter wheel gap (26) has a recess (30) in the transmitter wheel (16) and thus a distance (34) from a tooth crest (36) to a surface (38) of the tooth gap (20) is smaller than a distance from a tooth crest (36) to a surface (42) of the recess (30).

2. The sensor device (10) according to claim 1, wherein the third value (56) is smaller than the second value (54).

3. The sensor device (10) according to claim 1 or 2, wherein the recess (30) has a depth (32) of 0.1mm to 1.0 mm.

4. The sensor device (10) according to claim 1 or 2, wherein the output signal (46) is an analog output signal.

5. The sensor device (10) according to claim 1 or 2, wherein the output signal (46) is an electrical output signal (48).

6. The sensor device (10) according to claim 1 or 2, wherein the output signal (46) is a voltage (50).

7. The sensor device (10) according to claim 1 or 2, wherein the transmitter (14) has at least one transmitter element (44) for providing the output signal (46).

8. The sensor device (10) according to claim 7, wherein the transmitter element (26) is a Hall element.

9. Sensor device (10) according to claim 1 or 2, wherein the rotation characteristic is a number of revolutions of the rotating element (12).