DE102019218729A1 - Detection device for detecting rotational movement information of a rotating component of a drive train of a motor vehicle - Google Patents

Abstract

Detection device (1) for detecting rotational movement information, in particular relating to a speed and / or a direction of rotation, of a rotating component of a drive train of a motor vehicle, which detection device (1) has a rotationally symmetrical base body (3) with a plurality of rotary encoders (2) in the circumferential direction Has gaps (8) spaced apart on the base body (3) arranged or formed teeth (7), wherein at least two tooth flanks (9, 10) of the rotary encoder (2) are geometrically unequal.

Description

The invention relates to a detection device for detecting rotational movement information, in particular relating to a speed and / or a direction of rotation, of a rotating component of a drive train of a motor vehicle, which detection device comprises a rotary encoder having a rotationally symmetrical base body with a plurality of circumferentially spaced gaps arranged or formed on the base body Has teeth.

Acquisition devices for acquiring rotational movement information, in particular for determining rotational speeds of rotating components of drive trains of motor vehicles, are known in principle from the prior art. Two incremental encoders, which are phase-shifted by 90 ° with respect to one another, are usually used to determine the rotational speed and to provide information about the direction of rotation of such rotating components. Signals generated by such rotary encoders, in particular the two sensor signals detected by the sensors, can be evaluated accordingly, so that both speed determination and rotational direction information can be determined as a function of the individual signal edges.

Furthermore, it is known from the prior art to use only one sensor instead of two sensors phase-shifted by 90 ° and to encode the rotational movement information relating to the direction of rotation of the rotary encoder over the length of the increments, i.e. the length of the teeth or gaps. In other words, it is thus possible to detect from the signal of the individual sensor assigned to the rotary encoder in which direction the rotary encoder and thus the assigned component is rotating, since depending on the sequence of the signal edges, in particular based on the length of the successive signal edges, a corresponding evaluation is possible.

The invention is based on the object of specifying an improved detection device in which, in particular, only one rotary encoder is required to detect the rotational movement information.

The invention is achieved by a detection device having the features of claim 1. Advantageous refinements are the subject of the subclaims.

As described above, the invention relates to a detection device for detecting rotational movement information from rotating components or from a rotating component of a drive train of a motor vehicle. The rotational movement information can in particular include the speed and a direction of rotation of the rotating component. In other words, it is possible to use the detection device to detect in which direction and at which speed a rotary encoder assigned to a component is rotating, in order to be able to draw conclusions about the rotational speed and the direction of rotation of the corresponding component. The rotary encoder, which the detection device comprises, has a rotationally symmetrical base body, for example a disk or a cylinder, a plurality of teeth being formed or arranged on the base body in the circumferential direction, which are spaced from one another by gaps. In other words, a tooth profile consisting of teeth and gaps alternates on the outer surface of the base body, or teeth that are spaced from one another by gaps. A gap is thus arranged between two teeth of the tooth profile of the base body.

The invention is based on the knowledge that at least two tooth flanks of the rotary encoder are geometrically unequal. In the context of this application, a tooth flank can be understood as a transition on the outer surface of the rotary encoder, in which a tooth merges into a gap and vice versa. In other words, the tooth flank relates, for example, to the transition from a gap, that is to say an area of the rotary encoder with a smaller diameter, to a tooth, that is to say an area of the rotary encoder with a larger diameter. The geometry of the tooth flanks can ultimately be selected as desired, as long as at least two tooth flanks of the rotary encoder are geometrically unequal. Two tooth flanks are, for example, geometrically unequal if they differ from one another in their cross-section in one section, that is, if their pitch or shape differs in at least one section. Unequal tooth flanks thus lead to asymmetrical teeth. The mere reversal or mirroring of a tooth flank is not understood as “geometrically unequal” in the context of this application.

It is thus possible to identify which of the tooth flanks is detected first by means of the sensor in order to be able to detect rotational direction information in addition to a speed. Since the at least two tooth flanks of the rotary encoder are geometrically unequal, they generate a corresponding signal in the assigned sensor, which is arranged in the area of the rotary encoder, which enables an evaluation so that the rotational movement information can be recorded or determined. In other words, information on the direction of rotation can be impressed on the shape or the geometry of the tooth flanks, since it depends on the shape of the tooth flanks, that is to say individually detected tooth flank, a defined sensor signal can be recorded. In particular, due to the special shape of the tooth flanks, different frequencies can be generated in the sensor signal or the detected signal flank will rise or fall depending on the geometry of the tooth flanks.

In particular, according to the selected geometry of the tooth flanks, a distorted or warped voltage signal can be generated by the sensor compared to uniform teeth, which is characteristic of the respective tooth flank or tooth flank combination and thus creates the possibility of recognizing which of the tooth flanks first or in which Sequence of tooth flanks to be guided past the sensor. It is thus possible to code the direction of rotation information on the rotary encoder without changing the length of the individual teeth or increments or gaps. It is possible to use exactly one rotary encoder for each rotating component to record the rotational movement information, which in particular describes the speed and the direction of rotation of the rotating component.

As with conventional rotary encoders, a voltage signal can be generated inductively by moving the increments or the teeth past a corresponding sensor, for example by induction on a coil, the sensor signal being generated depending on the distance or the proximity of the outer surface of the rotary encoder to the coil becomes. As a result, the sensor signal is directly dependent on whether a tooth or a gap is moved past the sensor or influences the course of the tooth flanks, i.e. how the individual tooth flanks rise and fall as well as the sensor signal. By monitoring a magnetic flux over time and changing it, a voltage results from which, based on the known geometry of the tooth flanks, the direction in which the rotary encoder is moving can be derived. Since the sensor signal ultimately depends on the distance between the sensor and the outer surface of the rotary encoder, different signals are also generated by differently shaped tooth flanks. This means that the signal can be used to identify which tooth flank is passing the sensor.

For example, two flanks of the same tooth lying opposite one another in the circumferential direction can be designed to be unequal. Basically, a tooth has two tooth flanks that are opposite one another in the circumferential direction. Thus, each gap in the circumferential direction is followed by a tooth flank of a tooth, which rises to the maximum outer circumference of the tooth, which in turn is followed by a tooth flank in the circumferential direction, which connects the outer circumference of the tooth with the tooth gap following in the circumferential direction. According to this embodiment, it is possible to design the two tooth flanks that are opposite in the circumferential direction and are assigned to the same tooth, i.e. ultimately connect the tooth with the gaps surrounding it in the circumferential direction, to be non-uniform, i.e. to change their geometry in particular. For example, different gradients and / or different shapes of the tooth flanks can be selected so that when the tooth flanks are passed the sensor, different voltage signals are generated, thus creating the possibility of detecting which of the two tooth flanks is detected first and thus in which direction the rotary encoder turns.

The tooth flanks of all teeth that are opposite one another in the circumferential direction can be designed to be unequal. On the one hand, it is possible to design the teeth to be basically uniform, with each of the teeth having two different tooth flanks which connect the tooth to the gaps that are adjacent in the circumferential direction. Basically, the tooth profile of the teeth and gaps is uniform across the encoder, i.e. the tooth profile can continue periodically in the circumferential direction. In this case, however, the individual teeth can have different tooth flanks, so that the tooth flank in a first circumferential direction does not correspond to the tooth flank in a second circumferential direction.

The rotary encoder can furthermore have teeth with identical tooth flanks or at least two groups of teeth with identical tooth flanks, in particular alternately arranged in the circumferential direction, with at least two tooth flanks differing from teeth of different groups. According to this embodiment, it can be provided that all teeth of the rotary encoder have identical tooth flanks, ie that of each tooth the tooth flank facing the corresponding direction is identical to all other tooth flanks of the other teeth of the rotary encoder pointing in this direction, the teeth thus being identical to one another are trained. Alternatively, it is also possible for the rotary encoder to have several groups of teeth on its outer circumference, the individual groups having mutually identical tooth flanks, but two teeth of different groups having different tooth flanks.

The two groups can, for example, be arranged alternately in the circumferential direction, so that a tooth of a second group follows a tooth of a first group, the tooth flanks of the teeth of the two different groups being designed differently. It is thus possible to distinguish in which direction of rotation and with which speed the encoder is turned or the teeth are moved past the sensor.

The two different tooth flanks of a tooth can, for example, have a different pitch, for example the tooth can be designed in the shape of a sawtooth. It is thus possible, in particular, for a first tooth flank to be made significantly steeper, that is to say with a significantly higher slope, than the second tooth flank of the same tooth. For example, a sawtooth profile can be formed in which on a first side there is a sudden increase in the tooth compared to a gap diameter and on the other side of the tooth in the circumferential direction there is a comparatively flat, for example uniform or non-uniform drop to the diameter of the subsequent gap. The sawtooth profile is of course only one example, the design of the tooth flanks of a tooth with a different pitch is not limited to a sawtooth profile, but any profile can be used in which the first tooth flank has a different pitch than the second tooth flank of the same tooth.

Of course, the individual tooth flanks of the tooth or of the rotary encoder can have several sections with different pitches, so that each tooth flank can have different sections that have different pitches from one another. For example, two successive tooth flanks can be sinusoidal in the circumferential direction, in particular with different frequencies. Thus, in the circumferential direction, a first group of tooth flanks can be described by a first sine function and a second group of tooth flanks by a second sine function. In particular, the two sine functions can differ in their frequency.

For example, all teeth have a first tooth flank which is directed in a first circumferential direction, the first tooth flank being defined and designed based on a first sine function. Accordingly, all teeth of the rotary encoder according to this embodiment have second tooth flanks in a second circumferential direction, which are defined and formed based on a second sine function, wherein the first sine function and second sine function can differ in their frequencies. By guiding the tooth profile past the sensor, a corresponding voltage signal is generated, whereby, depending on the signal edges, a statement can be made about the direction in which the rotary encoder is rotating. The speed of rotation or the rotational speed can also be determined from the spacing of the successive maxima or minima of the signal edges.

The detection device can furthermore have a validation device and / or can be or can be connected to at least one validation device, which validation device is designed to validate determined rotational movement information based on a validation criterion. The validation device is therefore basically designed to validate, i.e. to confirm or refute, rotational movement information that has been recorded with the recording device, as described above. For this purpose, a specific validation criterion can be defined that enables a decision to be made as to whether the rotational movement information determined is realistic, i.e. possible and, for example, physically sensible. In particular in the case of different driving states in which a comparatively rapid change in the rotational movement information occurs, it is possible for the detection device to detect rotational movement information that deviates from the rotational movement actually carried out. For example, changes in the rotary movement, for example strong accelerations or decelerations or spontaneous changes in the direction of rotation of the rotating component, can lead to the individual sensor signals being distorted, that is, when a first tooth flank or a first tooth is decelerated or accelerated while a first tooth flank or a first tooth is being passed The sensor signal is distorted and the sensor signal is therefore incorrectly determined or evaluated.

The validation device makes it possible to check whether the detected rotational movement information basically corresponds to the movement carried out by the rotating component or whether a discrepancy occurs that needs to be corrected or that requires a new acquisition of the rotational movement information. The validation device can also be understood as an “observer” for the validation of the rotational movement information. The validation device can be part of a control device, for example as a “software module”, or it can itself comprise a control device to which corresponding validation criteria can be supplied.

In principle, all criteria or parameters suitable for checking the authenticity of the rotational movement information can be used as validation criteria. In particular, the validation device can be designed to use an intrinsic parameter of the rotating system or the rotating component and / or a driving state of a motor vehicle to which the detection device is assigned and / or an input variable of the motor vehicle To use validation of the determined rotational movement information.

The intrinsic parameters of the rotating system or of the rotating component can be understood to be all parameters conditioned by the component or the system, which basically allow the rotary movement to be checked or the corresponding rotary movement to be physically carried out. For example, an inertia or a mass or executable accelerations or other parameters describing a physical framework condition can be used as intrinsic parameters. As the driving state of the motor vehicle, among other things, the currently present, the preceding or the following driving state of the motor vehicle can be recorded and used to validate the rotational movement information. For example, starting from a stationary motor vehicle, that is, starting from a standstill, the rotational movement information can be recorded and a corresponding conclusion can be drawn as to whether the rotational movement information that was recorded by means of the recording device is valid. It is also possible to compare successive driving states and to check these with the rotational movement information or their changes. In particular, a change in the direction of rotation in the event of a change in the driving state can be checked.

Furthermore, input variables of the motor vehicle, i.e. various system input variables, for example an engine speed, a requested acceleration, the basic inertia of the system, a requested or current engine torque and the like, can be used to check whether the detected rotational movement information is valid.

In addition, the invention relates to a rotary encoder for a detection device according to the invention, as described above. The invention also relates to a drive train for a motor vehicle with at least one rotary encoder according to the invention and / or at least one detection device according to the invention. Of course, all the advantages, details and features that have been described in relation to the detection device according to the invention can be completely transferred to the rotary encoder according to the invention and the drive train according to the invention. Of course, the detection device, the rotary encoder and the drive train can be installed or used in a motor vehicle.

• 1 eine erfindungsgemäße Erfassungsvorrichtung;
• 2 ein erfindungsgemäßer Drehgeber für eine Erfassungsvorrichtung gemäß 1; und
• 3 ein Diagramm eines beispielhaften Sensorsignals.

The invention is explained below using an exemplary embodiment with reference to the figures. The figures are schematic representations and show:

• 1 a detection device according to the invention;
• 2 an inventive rotary encoder for a detection device according to 1 ; and
• 3rd a diagram of an exemplary sensor signal.

1 shows a detection device 1 for the acquisition of rotational movement information, for example relating to the speed and the direction of rotation of a component of a drive train (not shown). The detection device 1 has a rotary encoder 2 which is shown in the section. The rotary encoder 2 has a base body 3rd on, which is rotationally symmetrical, for example as a disk or cylinder. The rotary encoder 3rd is around an axis 4th rotatable, as if by an arrow 5 is indicated. The rotary encoder 2 is correspondingly coupled with the rotating component of the drive train, so that the rotary encoder executes the rotary movement that the component performs 2 is set in rotation and thus by the detection device 1 the rotational movement of the component can be deduced.

On the outer circumference of the base body 3rd instructs the rotary encoder 2 a tooth profile 6th on that in the circumferential direction of the encoder 2 multiple teeth 7th and gaps 8th having. Every tooth is visible 7th of two gaps 8th in the circumferential direction and surround each gap 8th is in the circumferential direction by two teeth 7th limited. The teeth 7th of the encoder 2 In this exemplary embodiment, each have a first tooth flank 9 and a second tooth flank 10 on that ultimately fill in the loopholes 8th with your teeth 7th connect, i.e. the minimum diameter of the base body 3rd of the encoder 2 in the area of a gap 8th with the maximum diameter of the base body 3rd of the encoder 2 in the area of a tooth 7th connect.

The tooth flanks 9 , 10 of each tooth 7th are geometrically unequal in this exemplary embodiment, that is to say that they are in the cross-sectional illustration shown in FIG 1 are shown differ from each other. In this exemplary embodiment, there are tooth flanks 9 , 10 different pitch selected, so that in this example the tooth flanks 9 rise flatter than the comparatively steeper tooth flanks 10 . Of course, the embodiment is only exemplary, so that other geometries or slopes or arrangements of the teeth can also be used 7th and tooth flanks 9 , 10 or gaps 8th possible are. The detection device 1 also has a sensor 11 on, which comprises, for example, a coil. By leading the tooth profile past 6th on the sensor 11 becomes a voltage in the sensor 11 induced by means of a control device 12th can be evaluated. With others The sensor creates words 11 a sensor signal that is dependent on the rotary movement of the rotary encoder 2 changed and thus based on the evaluation of the control device 12th the rotational movement information can be determined.

In particular, it is possible to determine at what speed, that is to say at what speed of rotation, and in which direction of rotation the rotary encoder 2 around the axis 4th is rotated. For this purpose, the shape of the signal flanks of the sensor signal can be determined, which correspond to the profile of the tooth flanks 9 , 10 surrender. In other words, it can thus be determined whether a tooth flank is first 10 and then the tooth flank 9 or the tooth flank first 9 and then the tooth flank 10 of a tooth 7th on the sensor 11 is passed. Thus, the direction of rotation of the encoder 2 and thus the one with the rotary encoder 2 coupled component of the drive train can be determined. Depending on the distances between the maxima and minima of the successive teeth 7th and gaps 8th attached to the sensor 11 can also be passed, the speed of the rotary encoder 2 executed rotary movement can be determined.

It is therefore advantageously possible to use only a single sensor 11 both the speed and the direction of rotation of the encoder 2 to be determined reliably, so that there is no need to provide a second sensor.

2 shows a tooth profile 6th a rotary encoder 2 according to a second embodiment. In the in 2 The section shown is three teeth 7th represented accordingly by gaps 8th are spaced from each other. Every tooth 7th has a first tooth flank 9 and a second tooth flank 10 on, which are geometrically designed differently. In this embodiment, the tooth flanks are 9 , 10 each defined by a sine function, the tooth flanks 9 by the same sine function and the tooth flanks 10 are defined by another sine function. The two sine functions differ, for example, in terms of frequency.

Every tooth produces accordingly 7th in the case of a rotary movement in a first direction of rotation, a characteristic first sensor signal in the sensor 11 and in the case of a rotary movement in the second direction of rotation, a characteristic second sensor signal that differs from the first sensor signal in the sensor 11 differs. Depending on the pitch or the shape of the tooth flanks 9 , 10 they induce a different voltage curve in the sensor 11 so that by means of the control device 12th it can be determined whether the tooth flank first 9 or the tooth flank first 10 of each tooth 7th the sensor 11 happens.

An exemplary diagram of the sensor signal is shown in 3rd shown. There is a first turn 13th , a second curve 14th and a third curve 15th shown, the different rotary movements or different tooth profiles 6th assigned. For example, with the reference number 15th denotes a curve in which a tooth profile 6th with uniform tooth flanks 9 , 10 is used. It can be seen that the signal edges of the signal are also uniform, so that no statement can be made about the direction in which the rotary encoder is going 2 is moved.

In contrast, the signal in the first curve is essentially sinusoidal 13th and the second curve 14th , for example, a counterclockwise and a clockwise rotation of the rotary encoder 2 or vice versa, distorted so that the direction of rotation can be determined. For example, denotes the first curve 13th that a sensor signal of the sensor 11 represents a movement of the tooth profile 6th out 2 in a first direction of rotation. A first tooth flank, for example a tooth flank, can be seen here 9 of each tooth 7th first on the sensor 11 passed so that there is a steep increase in the sensor signal, for example the voltage. This is followed by a comparatively flat drop in the sensor signal, for example the voltage, since the tooth flank 10 is designed to be correspondingly flatter, that is to say the frequency of the essentially sinusoidal signal differs from the geometry of the first tooth flanks 9 differs.

Will the rotary encoder 2 rotated in the opposite direction is activated by means of the sensor 11 or the control device 12th the second curve 14th recorded, whereby the first curve can be seen 13th from the second curve 14th a distinction can be made, in particular with regard to the slope of the signal flanks, which ultimately result from the rotational movement of the tooth flanks 9 , 10 relative to the sensor 11 , i.e. a corresponding rotation of the rotary encoder 2 around the axis 4th surrender. Furthermore, from the curves 13th , 14th the speed can be determined, for example from the distance between the maxima and minima.

The detection device 1 (see. 1 ) also has a validation device 16 on, in this embodiment with the control device 12th connected, for example in the control device 12th is integrated. The validation facility 16 is designed to provide rotational movement information that is obtained by means of the detection device 1 was determined to validate based on validation criteria. For example, the validation facility 16 for this purpose, an intrinsic parameter of the drive train or of the rotating component or of the motor vehicle can be supplied. In particular, drive parameters, for example current or requested powers or torques of the drive, physical conditions of the drive train or of the motor vehicle, for example masses, inertia, accelerations and the like of the validation device can be used 16 are fed.

In addition, it is also possible to send current, preceding or following driving states of the motor vehicle to the validation device 16 to send so that it can validate the determined rotational movement information based on the corresponding parameters. In particular, input variables of the motor vehicle, for example requested engine torques, pedal positions and the like, can be used to validate the rotational movement information.

It goes without saying that all advantages, details and features of the exemplary embodiments shown in the individual figures can be exchanged, transferred and combined with one another as required.

List of reference symbols

1

Detection device

2

Rotary encoder

3

Base body

4th

axis

5

arrow

6th

Tooth profile

7th

tooth

8th

gap

9, 10

Tooth flank

11

sensor

12th

Control device

13-15

Curve

16

Validation facility

Claims (10)

Detection device (1) for detecting rotational movement information, in particular relating to a speed and / or a direction of rotation, of a rotating component of a drive train of a motor vehicle, which detection device (1) has a rotationally symmetrical base body (3) with a plurality of rotary encoders (2) in the circumferential direction Has gaps (8) spaced apart teeth (7) arranged or formed on the base body (3), characterized in that at least two tooth flanks (9, 10) of the rotary encoder (2) are geometrically unequal. Detection device according to Claim 1 , characterized in that two tooth flanks (9, 10) of the same tooth (7) lying opposite one another in the circumferential direction are unequal. Detection device according to Claim 1 or 2 , characterized in that the opposing tooth flanks (9, 10) of all teeth (7) in the circumferential direction are unequal. Detection device according to one of the preceding claims, characterized in that the rotary encoder (2) has teeth (7) with identical tooth flanks (9, 10) or the rotary encoder (2) has at least two groups of teeth (7), in particular alternately arranged in the circumferential direction. with identical tooth flanks (9, 10), at least two tooth flanks (9, 10) differing from teeth (7) of different groups. Detection device according to one of the preceding claims, characterized in that two tooth flanks (9, 10) of a tooth (7) have different slopes, in particular sawtooth-shaped. Detection device according to one of the preceding claims, characterized in that at least two successive tooth flanks (9, 10) are sinusoidal, in particular with different frequencies. Detection device according to one of the preceding claims, characterized in that the detection device (1) has at least one validation device (16) and / or can be or is connected to at least one validation device (16), which validation device (16) is designed to provide rotational movement information validate based on a validation criterion. Detection device according to Claim 7 characterized in that the validation device (16) is designed to use an intrinsic parameter of the rotating system and / or a driving state of a motor vehicle to which the detection device is assigned and / or an input variable of the motor vehicle to validate the determined rotational movement information. Rotary encoder (2) for a detection device (1) according to one of the preceding claims Drive train for a motor vehicle with at least one rotary encoder (2) Claim 9 and / or at least one detection device (1) according to one of the Claims 1 to 8th .

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