阅读说明：本技术 用于运行具有用来传递转矩的离合器设备的车辆的驱动系的方法 (Method for operating a drive train of a vehicle having a clutch device for transmitting torque ) 是由 M.韦勒 E.雷斯福尔 F.奥伯比希勒 P.拉芬 A.施尼策勒 M.齐默曼 于 2019-08-20 设计创作，主要内容包括：本发明涉及一种用于运行具有离合器设备(3)的车辆(2)的驱动系(1)的方法,其中,所述离合器设备(3)能通过操纵机构(4)予以操纵,以便能切换地传递转矩；其中,所述操纵机构(4)的第一状态(5)并且由此所述离合器设备(3)的第二状态(6)能通过所述操纵机构(4)的驱动单元(8)的位置(7)来调整；其中,该方法至少包括如下步骤：a)确定对所述离合器设备(3)提出的第一转矩要求(9)是恒定的；和b)确定所述驱动单元(8)的第一位置(11)在所述间隔(10)内是恒定的；和,然后,c)利用抖动函数(13)操控所述驱动单元(8),其中,所述驱动单元(8)的位置(7)连续地以所述第一位置(18)为幅度改变；和d)如果不再满足在步骤a)和b)中列出的条件,则结束所述抖动函数(13)。(The invention relates to a method for operating a drive train (1) of a vehicle (2) having a clutch device (3), wherein the clutch device (3) can be actuated by an actuating element (4) in order to be able to transmit torque in a switchable manner; wherein a first state (5) of the operating mechanism (4) and thus a second state (6) of the clutch device (3) are adjustable by means of a position (7) of a drive unit (8) of the operating mechanism (4); wherein, the method at least comprises the following steps: a) determining that a first torque request (9) made to the clutch device (3) is constant; and b) determining that a first position (11) of the drive unit (8) is constant within the interval (10); and, then, c) operating the drive unit (8) with a dithering function (13), wherein the position (7) of the drive unit (8) continuously changes with the first position (18) as an amplitude; and d) ending the dithering function (13) if the conditions listed in steps a) and b) are no longer met.)

1. Method for operating a drive train (1) of a vehicle (2) having a clutch device (3), wherein the clutch device (3) can be actuated by an actuating element (4) in order to be able to transmit a torque in a switchable manner, wherein a first state (5) of the actuating element (4) and thus a second state (6) of the clutch device (3) can be set by means of a position (7) of a drive unit (8) of the actuating element (4), wherein the method comprises at least the following steps:

a) determining that a first torque request (9) made to the clutch device (3) is constant at least over an interval (10) of at most 100ms, or has a maximum torque deviation (11) of at most 100Nm within the interval (10); and

b) determining that a first position (18) of the drive unit (8) is constant over the interval (10) or has a maximum position deviation (12) corresponding to the maximum torque deviation (11); and the combination of (a) and (b),

c) -operating the drive unit (8) with a dithering function (13), wherein the position (7) of the drive unit (8) is continuously varied with the first position (18) as an amplitude; and

d) ending the dithering function (13) if the conditions listed in steps a) and b) are no longer met.

2. The method as claimed in claim 1, wherein the method with steps a) to d) is only initiated if the first torque request (9) for the clutch device (3) is greater than a first limit value (14).

3. The method according to any of the preceding claims, wherein the first torque requirement (9) is at least 800 newton meters.

4. Method according to one of the preceding claims, wherein the method with steps a) to d) is only introduced if there is an overheating warning of the drive unit (8).

5. Method according to one of the preceding claims, wherein the drive unit (8) comprises an electric motor (15), wherein a rotational movement (16) of the electric motor (15) is converted into a translational movement (17) for actuating the clutch device (3), wherein the position (7) is an angular position of the rotational movement (16) which can be actuated by a control unit (16); wherein the position (7) can be actuated by the control unit (17) with an angle value of at least 5 and at most 30.

6. Method according to claim 5, wherein step c) comprises changing said position (7) between at least a second position (19) and a third position (20), wherein said second position (19) and said third position (20) are spaced from said first position (11) in mutually different rotational directions (21, 22) of said drive unit (8), respectively:

at least 15 degrees, or alternatively,

at most 100 degrees.

7. Method according to any of the preceding claims 5 and 6, wherein in case of the first position (18) determined in step b) the rotational movement (16) of the angle value of 10 degrees corresponds to a change of the torque requirement (23) of at least 25 Newton meters.

8. The method according to any of the preceding claims, wherein step c) comprises changing the position (7) between at least a second position (19) and a third position (20), wherein the second position (19) corresponds to a second torque requirement (24) and the third position (20) corresponds to a third torque requirement (25), wherein the second torque requirement (24) and the third torque requirement (25) differ by at most 150 newton-meters.

9. Method according to any one of the preceding claims, wherein step c) comprises varying the position (7) between at least a second position (19) and a third position (20), wherein the frequency (26) of the dithering function (13) is between 0.2 and 4 hertz.

10. Method according to any of the preceding claims, wherein the drive unit (8) comprises an electric motor (15) which can be operated by means of multiphase currents, wherein, in the case of a substantially constant torque demand (23), the electric motor (15) is stationary and only one of the phases is loaded with branch currents, wherein a movement of the electric motor (15) and thus a plurality of phases is loaded with branch currents is ensured by the method, wherein the substantially constant torque demand (23) is responded to by means of a varying torque.

11. The method according to claim 10, wherein the motor (15) is controlled by the dithering function (13) such that the motor (15) can follow oscillations (27) of the dithering function (13) as the motor (15) moves.

12. Vehicle (2) having a clutch device (3), wherein the clutch device (3) is assigned an electronic control unit (28) which is suitable and set up for carrying out the method according to one of the preceding claims.

Technical Field

The invention relates to a method for operating a drive train of a vehicle having a clutch device, in particular for transmitting and/or distributing torque.

The invention relates in particular to a method for driving power control in demand-oriented all-wheel systems and/or drive axle locks, and to vehicles which are designed in a relevant manner by means of control and in which information is available about the current motor torque, the longitudinal acceleration, the lateral acceleration, the yaw rate (which represents the speed of the vehicle about a vertical axis), the steering angle and/or the wheel rotational speed. The invention relates in particular to all-wheel-drive vehicles in which either the rear axle or the front axle can be engaged (locally (anti) and/or temporarily) by means of an electronically controlled clutch device. Alternatively or cumulatively, the invention can also be applied to a shaft lock, in particular a driving shaft lock, in which one side of the shaft can be at least partially decoupled from the opposite side (in the axial direction) of the shaft by means of an electronically regulated clutch device. This makes it possible to distribute the torque between the two wheels of the axle as desired. The clutch device is preferably an electromechanical clutch system, in particular an electronically controlled laminated clutch (Lamellenkupplung). The electromechanical clutch system is in particular a clutch system or a clutch device in which an electronic servomotor (electric motor) is provided for adjusting the clutch force. For such electronic servomotors, a mechanical coupling is usually produced between the rotational angle of the motor (rotational movement) and the clutch travel distance (translational movement).

Background

For actuating the respective clutch device, a control unit (ECU) is known to which (zuordnen) electronics are assigned. Such an electronic control unit can be integrated into the clutch device itself or into an electronic control system of the vehicle, in particular of the upper stage of the drive train.

In order to ensure the best possible driving dynamics of the demand-oriented all-wheel drive vehicle even in extreme cases (e.g. frequent load changes, repeated starting in mountainous areas, repeated changes between single-axle operation and all-wheel operation, etc.), high demands are placed on the electronic control unit of the clutch device. In particular, in the extreme case described above, the electronic control unit, the power stage and/or the electronic servomotor can heat up rapidly and even overheat in this case due to the high stresses. The known electronic control unit, power stage and/or electronic servomotor are switched off in this case, in particular in the event of overheating, in order to avoid permanent damage to the respective component, in particular to the control unit and/or the electronic servomotor.

However, this overheating protection measure has the following disadvantages: they directly influence the operating or driving behavior of the vehicle and sometimes temporarily lead to a failure of the demand-oriented (budarvillientienten) all-wheel system. This can result in a loss in driving comfort and/or driving power that can be perceived by the driver.

Disclosure of Invention

Based on this, it is an object of the present invention to at least partially solve the problems described for the prior art. In particular, a method for operating a drive train of a vehicle is to be proposed, which provides overheating protection that (hardly) influences the driving behavior of the vehicle (to the greatest possible extent). In particular, the method should lead to an undesired overheating of the Electronic Control Unit (ECU) and/or the electronic servomotor even in extreme cases, without the driver noticing a (noticeable) power reduction.

These objects are achieved with a method according to the features of patent claim 1. Further advantageous embodiments of the method are given in the dependent patent claims. It should be pointed out that the features listed individually in the patent claims can be combined with one another in any technically meaningful way and define further designs of the invention. Furthermore, the features given in the patent claims will be expressed and explained more precisely in the description, in which further preferred designs of the invention are shown.

The method for operating a drive train of a vehicle having a clutch device facilitates this. The clutch device can be actuated by an actuating mechanism in order to be able to transmit torque in a switchable manner. The first state of the actuating mechanism and thus the second state of the clutch device can be adjusted by the position of the drive unit of the actuating mechanism (einstellen). The method at least comprises the following steps:

a) determining that the first torque request to be made to the clutch device is constant at least for an interval of at most 100ms [ milliseconds ] or has a maximum torque deviation of at most 100Nm [ newton meters ], preferably at most 20Nm, particularly preferably at most 10Nm, within this interval; and

b) determining that the first position of the drive unit is constant over the interval or has a maximum positional deviation (e.g. at most 2 tic or 1 tic) corresponding to a maximum torque deviation (a change in position corresponding to a change in torque demand or to a change in torque transmitted through the clutch arrangement); and (then),

c) manipulating the drive unit with a dithering function, wherein the position of the drive unit continuously varies in magnitude with the first position; and

d) if the conditions listed in steps a) and b) are no longer met, the dithering function is ended.

The aforementioned sequence of method steps occurs during normal operation of the drive train of the vehicle. Method steps a) to d) can be repeated continuously during operation of the drive train. Method steps a) to d) can be carried out or repeated at least temporarily also in parallel.

The method proposed here is based in particular on the following idea: the actuation of the clutch device is influenced in such a way that the drive unit is moved (rather than being stationary) in order to meet a predetermined torque demand or in order to transmit a predetermined torque via the clutch device. That is to say that in fact, in particular, the torque transmitted is also changed.

In particular, the drive unit comprises an electric machine which can be operated by means of multiphase currents, wherein, in the case of a substantially constant torque demand, the electric machine is stationary and only one of the phases of the multiphase system is loaded with branch currents. This method ensures that the motor is moved so as to branch the current to a plurality of phase loads (betalasten).

In particular, the load (Belastung) of one of the phases (which is loaded with the branch current when the position of the electric machine is constant) can thus be reduced, since a plurality of phases are loaded by the movement of the electric machine for the rotation of the electric machine. This makes it possible to at least delay or even completely prevent overheating of the drive unit.

By means of the dithering function, the electric motor is in particular controlled such that the electric motor can follow the oscillations of the dithering function as the electric motor moves. The electric machine should in particular perform exactly one movement, so that instead of one phase, a plurality of phases of a multiphase system are loaded with current.

The dithering function is the manipulation of the motor such that the motor moves in amplitude with the first position, or oscillates in amplitude with the first position. Using the wobble function, on the one hand, the electric machine is moved, wherein, on the other hand, a torque which is as constant as possible is to be transmitted in accordance with the current first torque request actually in accordance with step a).

The clutch device is preferably an electromechanical clutch system, in particular an electronically controlled laminated clutch. The electromechanical clutch system is in particular a clutch system or a clutch device in which an electronic servomotor (an electric machine as an actuating element) is provided for adjusting the clutch force. For such electronic servomotors, a mechanical coupling is usually produced between the rotational angle of the motor (rotational movement) and the clutch travel distance (translational movement).

In particular, the torque demand of the control unit is achieved by the clutch device by, for example, a displacement of the laminations of the laminated clutch. For this purpose, the actuating element is moved in the first state and thus adjusts the second state of the clutch device (the position of the laminations for transmitting the torque according to the torque demand). In a first state of the actuating element, the drive unit of the actuating element has a defined position.

According to step a), it is determined (for example, checked by the control unit) that the first torque request made to the clutch device is constant at least for an interval of at most 100ms [ milliseconds ] or has a maximum torque deviation of 100Nm [ newton meters ], preferably 20Nm, particularly preferably at most 10Nm, within this interval.

It is determined from step b) that the first position of the drive unit is constant over the interval or has a maximum position deviation corresponding to a maximum torque deviation (a change in position corresponding to a change in torque demand or to a change in torque transmitted through the clutch device).

Steps a) and b) can also be carried out jointly if desired. In particular, the further conditions according to step b) or a) result from the determination according to step a) or b), respectively.

In particular, the drive unit comprises an electric motor, wherein a rotational movement of the electric motor is converted into a translational movement for actuating the clutch device. The position is an angular position of the rotary movement that can be manipulated by the control unit.

In particular, the rotational movement of the drive unit can be controlled in the order of "tic". An tic corresponds in particular to an angle value (respectively identical) of 5 to 30 angles, in particular 5 to 10 angles. Preferably, the 360 degree rotational motion can be divided into 42 tic or 64 tic.

The position can preferably be determined by means of an angle value. The smallest angle value that can be set by the control unit is in particular exactly one tic.

In the case of the (first) position determined in step a) or b), a rotational movement of an angular value of 10 degrees corresponds in particular to a variation of the transmitted torque of at least 0.1Nm and/or at most 25Nm, preferably at least 1Nm and/or at most 15 Nm.

It is thus checked in particular whether the drive unit is only moving within a limited dimension (i.e. performing a rotational movement) or even stationary. In this case, overheating may be and is expected, since in particular, for example, only one phase of the polyphase system is loaded or acted upon by the current necessary for actuating the first position.

If it is therefore determined that the drive unit has not moved sufficiently and that overheating may be present or occurs, a dithering function is introduced according to step c), by means of which the position of the drive unit is changed, in particular continuously, by the first position as an amplitude.

In this case, the position is changed in particular in small dimensions, so that on the one hand the electric drive unit rotates (and the phases of the polyphase system are supplied with current) and on the other hand the torque transmitted is only changed to a certain extent, so that driving comfort is not influenced or is not influenced to a significant extent.

According to step d), in particular when the movement of the drive unit is present again to a sufficient extent (for example due to a small or varying torque requirement), the dithering function is then ended.

The method with steps a) to d) is only initiated if the first torque request to the clutch device is greater than a first limit value.

The first torque requirement is in particular at least 500Nm, preferably at least 800Nm, particularly preferably at least 1000 Nm.

In particular, the method is then carried out when an (impermissible) overheating of components of the drive unit (for example, power electronics, etc.) is expected. Overheating is more likely to be expected when large torques are transmitted, since for this purpose a large current is necessary, by means of which the clutch device is moved to the desired state.

The method with steps a) to d) is only introduced if there is an overheating warning of the drive unit. In particular, temperature measurements or computer-based and/or model-based temperature determination may be carried out, for example. The overheating warning may be set as a signal of the control unit, so that the method is only performed after the signal has been set.

The drive unit may comprise an electric motor, wherein a rotational movement of the electric motor is converted into a translational movement for operating the clutch device. The position is an angular position of the rotary movement that can be manipulated by the control unit. This position can be manipulated by the control unit with an angle value of at least 5 degrees and at most 30 degrees ("tic").

Step c) comprises, in particular, changing the position between at least a second position and a third position, wherein the second position and the third position are spaced apart from the first position in mutually different rotational directions of the drive unit:

at least 15 degrees, preferably at least 20 degrees, particularly preferably at least 25 degrees; and/or

An angle of at most 100, preferably at most 75, particularly preferably at most 45.

In particular, the second position is arranged substantially equally far from the third position, spaced apart from the first position.

In particular, in the case of the first position determined in step b), a rotational movement of an angular value of 10 degrees corresponds to a variation of the transmitted torque of at least 0.1Nm and/or at most 25Nm, preferably at least 1Nm and/or at most 15 Nm.

In particular, step c) comprises changing the position between at least the second position and a third position, wherein the second position corresponds to the second torque request and the third position corresponds to the third torque request, wherein the second torque request and the third torque request differ from each other by at most 150Nm, in particular by at most 100Nm, preferably by at most 50 Nm. In particular, the first torque request for the first position differs from the second and third torque requests by the same respective value.

In particular, step c) comprises varying the position between at least the second position and the third position, wherein the frequency of the dithering function is between 0.2 and 4 hertz, in particular between 0.5 and 2 hertz.

In particular, the dithering function has a sinusoidal waveform signal, so that the drive unit oscillates sinusoidally with the first position as an amplitude (with the amplitude of the difference of the second position and the third position). Other signal shapes are of course possible.

The second position and the third position may be changed during step c) or selected differently (e.g. depending on the current torque demand, etc.).

The drive unit comprises in particular an electric machine which can be operated by means of multiphase currents, wherein, in the case of a substantially constant torque demand, the electric machine is stationary and only one of the phases is loaded with branch currents. By this method, the movement of the motor will be ensured, thereby branching the current to a plurality of phase loads.

With the dithering function, the motor may be manipulated such that the motor is able to follow the oscillations of the dithering function as the motor moves. The dithering function thus has in particular a frequency and an amplitude, so that the motor can follow at least this frequency (with mechanical movement).

Furthermore, a vehicle having a clutch device is proposed, wherein the clutch device is assigned an electronic control unit which is suitable and set up for carrying out the aforementioned method. The control unit implements the method, in particular during operation of the vehicle.

Clutch devices are used in particular for transmitting torque, for example from a drive machine (for example an internal combustion engine or an electric drive) of a motor vehicle to a drive train. The clutch device serves in particular to distribute the torque variably over different axles of the vehicle. The electronic control unit may comprise a program-controlled microprocessor and an electronic memory, in which a corresponding control program is stored.

Clutch devices usually have a laminated clutch and at least one (externally controllable) actuating unit for activating or deactivating the torque transmission. The actuating unit may comprise an electric motor, for example an electronic actuator, in particular an electronic servomotor. The laminated clutch usually comprises at least one compressible laminated core which is compressible by means of an actuating unit in order to introduce a torque transmission. The operating unit is usually controlled by an electronic control unit, which in turn outputs an electrical control current to the operating unit via a corresponding operating line.

A system for data processing is also proposed, which comprises a processor adapted and/or configured such that it carries out the method described or claimed herein or (individually, partially or completely) carries out its steps. Furthermore, a computer program may be provided, which comprises instructions that, when the program is implemented by a computer, cause the computer to carry out the steps of the method (individually, partially or completely).

The details, features and advantageous designs described above in connection with the method may accordingly also be found on the vehicle proposed here and vice versa. Reference is hereby made in full to the description thereof made for a detailed description of the features.

It is to be noted in advance that the terms "first", "second", … are used here primarily (only) to distinguish one or more items, parameters or processes of the same type, i.e. in particular, but not necessarily, the relation and/or sequence of these items, parameters or processes with respect to one another is predefined. If a relationship and/or order is necessary, such will be explicitly described herein or will become apparent to those of ordinary skill in the art upon examination of the specific design described.

Drawings

The invention and the technical field are described in detail below with the aid of the accompanying drawings. It should be noted that the present invention is not limited by the illustrated embodiments. Unless explicitly stated otherwise, it is also possible in particular to extract some aspects of the situation depicted in the figures and to combine them with other constituents and knowledge from the present description. Schematically showing:

fig. 1 shows a vehicle with a clutch device for transmitting torque from a drive unit to a drive train; and

fig. 2 shows two diagrams for describing the method.

Detailed Description

Fig. 1 shows a vehicle 2 having a clutch device 3 for transmitting torque from a drive machine 29 to a drive train 1. The clutch device 3 is assigned an electronic control unit 28 which is suitable and configured for carrying out the method described above or for carrying out the method. The clutch device 3 can be actuated by an actuating element 4 in order to be able to transmit torque in a switchable manner. The first state 5 of the actuating element 4 and thus the second state 6 of the clutch device 3 can be adjusted by the position 7 of the drive unit 7 of the actuating element 3. The drive unit 7 is here an electric motor 15, wherein a rotational movement 16 of the electric motor 15 is converted into a translational movement 17 for actuating the clutch device 3. Position 7 is the angular position of the rotary motion 16 that can be manipulated by the control unit 28.

The actuating element 3 is controlled by an electronic control unit 28, which in turn outputs an electrical control current to the actuating element 3 via the respective actuating element.

Fig. 2 shows two diagrams for describing the method. In the above diagram, the (actual) position 7[ angle value ] of the drive unit 8 (or its position 7 which is necessary for transmitting the torque demand 23 which is currently present in each case) is shown on the vertical axis, and the torque demand 23[ Nm ] is shown. The time 31 seconds is plotted on the horizontal axis. The curve shown shows the trend of the position 7 with respect to the target position 24.

In the following chart, the effective value [ ampere ] of the current 30 is shown on the vertical axis. Time 31 is plotted on the horizontal axis. The curve shown shows the trend of the current 30. The dashed segment of the curve shows the current 30 that exists when the method is not performed.

According to step a), it is determined (for example, checked by the control unit 28) that the first torque request 9 to the clutch device 3 is constant within the interval 10 or has the largest torque deviation 11 within the interval 10.

According to step b), it is determined that the first position 18 of the drive unit 8 is constant over the interval 10 or has the largest position deviation 12 corresponding to the largest torque deviation 11 (the change in position 7 corresponding to the change in torque demand 23 or to the change in torque transmitted through the clutch device 3).

If it is determined that the drive unit 8 is not moving sufficiently and that (eintreten) overheating may be present or occur, a dithering function 13 is introduced according to step c), by means of which the position 7 of the drive unit 8 is continuously varied with the first position 18 as an amplitude.

The position 7 is changed in this case in small dimensions, so that on the one hand the electric drive unit 8 rotates (and the currents 30 are applied to the phases of the polyphase system), and on the other hand only the transmitted torque is changed to a certain extent, so that the driving comfort is not or only not significantly influenced.

According to step d), when the movement of the drive unit 8 is present again to a sufficient extent (for example due to a small or varying torque demand 23), the dithering function 13 is then ended.

The method with steps a) to d) is only initiated if the first torque request 9 for the clutch device 3 is greater than the first limit value 14.

When an (impermissible) overheating of components of the (erwarten) drive unit 8 (for example, power electronics, etc.) is expected, the method is then carried out, it is more likely that an overheating is expected when a high torque is transmitted, since for this purpose a high current 30 is necessary, by means of which the clutch device 3 is moved to the desired (gew ü nschten) state.

The method with steps a) to d) is only introduced if there is an overheating warning of the drive unit 8. The overheating warning is set as a signal 32 of the control unit 28, so that the method is only performed after setting said signal 32.

Step c) comprises changing the position 7 between the second position 19 and the third position 20, wherein the second position 19 and the third position 20 are spaced from the first position 18 by a certain angular value in mutually different rotational directions 21, 22 of the drive unit 8.

Step c) includes changing position 7 between a second position 19 and a third position 20, wherein the second position 19 corresponds to the second torque request 24 and the third position 20 corresponds to the third torque request 25. Step c) further comprises changing the position 7 between the second position 19 and the third position 20, wherein the frequency 26 of the oscillation 27 of the dithering function 13 is chosen such that the drive unit 8 follows the oscillation 27.

List of reference numerals

1 drive train

2 vehicle

3 Clutch device

4 operating mechanism

5 first state

6 second state

7 (actual) position

8 drive unit

9 first torque request

10 space apart

11 maximum torque deviation

12 maximum positional deviation

13 dithering function

14 first limit value

15 machine

16 rotational movement

17 translational movement

18 first position

19 second position

20 third position

21 first direction of rotation

22 second direction of rotation

23 Torque request

24 second torque request

25 third Torque request

26 frequency

27 oscillating

28 control unit

29 drive machine

30 current (l)

31 time (h)

32 signal