DE102020214121A1 - Emergency operation strategy for a motor vehicle drive train comprising an automatic transmission that can be driven by a plurality of drive machines - Google Patents

Abstract

The invention relates to an emergency operation strategy for a drive train (2) of a motor vehicle (1) with an automatic transmission (30) that can be driven by several drive machines (10, 20, 50), wherein in the power flow between the automatic transmission (30) and a first of these drive machines (10) a separating clutch (34) is arranged. This separating clutch (34) and a gear change device (35) of the automatic transmission (30) are controlled by an electrohydraulic control unit (36) of the automatic transmission (30) on the basis of specifications from an electronic control unit (31) of the automatic transmission (30), this electronic control unit ( 31) monitors the activation of the separating clutch (34) and gear change device (35) with regard to admissibility and proper implementation and reacts to the situation in the event of a fault. In the event of a fault, the electronic control unit (31) of the automatic transmission (30) generates a transmission message that depends on the severity of the fault and transmits it to other electronic control units (11, 21) in the motor vehicle (1). Measures are defined in this transmission message which are to be processed by different electronic control devices (11, 21, 31) depending on the severity of the error.

Description

The invention relates to a strategy for operating a drive train in a motor vehicle in emergency transmission operation, according to the preamble of claim 1. The invention also relates to an automatic transmission operated using this strategy and a motor vehicle comprising an automatic transmission operated using this strategy.

Modern motor vehicles whose drive train includes an internal combustion engine, an electric motor and an automatically shifting transmission that can be driven by these two engines—also known as an automatic transmission—are widely known from the prior art. An automatic transmission with an integrated electric motor is usually referred to as a hybrid transmission. At least the internal combustion engine can usually be uncoupled from the transmission input shaft of the automatic transmission by means of a separating clutch. Due to the specific control requirements for operating the combustion engine, electric motor and automatic transmission, different control units are usually provided for these assemblies, namely an electronic engine control unit for the combustion engine, an electronic hybrid control unit including power electronics for the electric motor that can also be used as a generator, and an electronic transmission control unit for the automatic transmission , whose gear changes are usually initiated by an electrohydraulic control unit of the automatic transmission as specified by the electronic transmission control unit.

The electronic transmission control unit usually includes a diagnostic system for monitoring the transmission-side functions, in particular for monitoring the actuation of the separating clutch and gear change device, so that the electronic transmission control unit can initiate appropriate measures for the respective error in the event of a fault. Usually, when less serious faults are detected in the automatic transmission, for which a gear change in the automatic transmission is still possible, the electronic transmission control unit initiates replacement functions tailored to the specific fault, so that further operation of the automatic transmission is still possible with the acceptance of minor restrictions. On the other hand, if serious errors are detected in the automatic transmission, especially if errors are detected which make it impossible to change gears in the automatic transmission, the electronic transmission control unit usually initiates an emergency program with at least severely restricted drivability of the motor vehicle in order to save the automatic transmission from further destruction. Examples of common emergency programs for automatic transmissions can be found in the DE 101 11 830 A1 , the EP 0 316 358 B1 , the EP 1 431 626 A1 and the DE 198 58 540 A1 .

That's how she beats DE 101 11 830 A1 proposes, as an emergency program for a continuously variable automatic transmission with belt-type variator and electro-hydraulic control, to open the starting clutch of the automatic transmission when the event that triggers the emergency program occurs, so that the motor vehicle rolls out as a result of the interruption in traction. When the engine is restarted for the first time and the error persists, the valve in the electrohydraulic control unit provided for controlling the starting clutch is then hydraulically reset, combined with the variator provided for setting the transmission ratios being pressurized with a hydraulically preset pressure ratio between the primary and secondary sides of the variator.

As an emergency program for a stepped automatic transmission with electrohydraulic control, the EP 0 316 358 B1 proposes to shift the automatic transmission into its highest gear when the event that triggers the emergency program occurs. If the engine is subsequently restarted and the error persists, the automatic transmission again hydraulically engages the highest gear when the gear is engaged and also remains in this highest gear. Deviating from this, the emergency program of the EP 1 431 626 A1 described 6-speed automatic transmission as an emergency gear, the fifth forward gear. This prevents the drive motor from overspeeding, since the sixth forward gear in the automatic transmission here has an overdrive ratio.

A differentiated emergency program for a stepped automatic transmission is from the DE 198 58 540 A1 famous. Here, when the event that triggers the emergency program occurs in the automatic transmission, an emergency gear is engaged, which depends on the gear actually engaged at the time of the error. If the engine is subsequently restarted and the error is still present, a predefined emergency gear is engaged hydraulically in the automatic transmission when the gear is engaged, which gear ratio makes it possible for the motor vehicle to cope with an incline that is typical for a parking garage. The automatic transmission remains in this emergency gear for as long as the error causing the emergency program is present.

The present invention is based on the finding that in the drive train described above, a limited emergency operation of the automatic transmission in a firmly predefined emergency gear in conjunction with the possibility of electric motor drive is problematic if the power flow between the internal combustion engine and Do not allow the separating clutch provided for the automatic transmission to fully open.

It is therefore an object of the present invention, based on the prior art mentioned, to create an improved emergency operation strategy for a drive train of a motor vehicle, which comprises a plurality of drive machines and an automatic transmission that can be driven by these drive machines and in which in the power flow between a first drive machine and the automatic transmission a Separating clutch is arranged. According to the invention, this object is achieved by an emergency operation strategy with the features of patent claim 1.

The invention is based on an emergency operation strategy for a drive train of a motor vehicle comprising a plurality of drive units and an automatic transmission which can be driven selectively, in parallel or in series by these drive units, in which a separating clutch is arranged in the power flow between a drive shaft of a first drive unit and a transmission input shaft of the automatic transmission. Both this separating clutch and a gear change device of the automatic transmission are actuated by an electrohydraulic control unit of the automatic transmission on the basis of specifications from an electronic control unit of the automatic transmission, with the electronic control unit of the automatic transmission monitoring the actuation of the separating clutch and gear change device with regard to admissibility and proper implementation and reacting to the situation in the event of a fault .

The first drive machine is preferably designed as an internal combustion engine, while the second drive machine is designed as an electric motor, the drive shaft of which is constantly connected or operatively connected to the transmission input shaft of the automatic transmission. In this way, the automatic transmission can be driven selectively or in parallel by the internal combustion engine and the electric motor.

Provision can then be made for the drive train to have a third drive machine, which is designed as an electrical machine, the drive shaft of which is either permanently connected or operatively connected to the drive shaft of the first drive machine or can be connected or operatively connected to the drive shaft of the first drive machine, so that the Automatic transmission can be driven in series by the first and the third prime mover.

Provision can also be made for an additional drive machine to be in the form of an electric machine, the drive shaft of which is permanently connected or operatively connected to a transmission output shaft of the automatic transmission.

In the event of an error, the electronic transmission control unit generates a message that depends on the severity of the error and transmits this message to other electronic control units in the motor vehicle, with measures being defined in the message that are to be processed by different electronic control units depending on the severity of the error.

In a preferred embodiment, the emergency operation strategy has three escalation levels graded according to the severity of the error.

As the most serious of these three escalation levels, it is proposed that if the electronic transmission control unit detects a serious error in the separating clutch or in the activation of the separating clutch that prevents the separating clutch from opening safely, the measure should be to switch off all drive machines of the automatic transmission.

As an alternative to this or in addition to this, in the most serious escalation level, even if the electronic control unit of the automatic transmission detects a serious error that prevents differentiated drive of the automatic transmission with the drive machines, switching off all drive machines of the automatic transmission can be defined as a measure.

The execution of all measures defined in the most serious escalation level is preferably initiated and possibly also monitored by an electronic control unit which is assigned to at least one of the drive units of the motor vehicle, for example by an electronic control unit of the second drive unit.

As the middle of the three escalation levels of the emergency operation strategy, it is proposed that when the electronic control unit of the automatic transmission detects a medium-severe error in which limited operation of the automatic transmission is still possible without changing gears, the action defined is to engage a predefined emergency gear in the automatic transmission.

In this case, the implementation of engaging the emergency gear is preferably initiated by the electronic control unit of the automatic transmission. Any activation of a drive machine of the motor vehicle that is necessary for the automatic transmission is preferably initiated by an electronic control unit and, if necessary also monitored, which is assigned to at least one of the drive units of the motor vehicle, for example by the electronic control unit of the second drive unit.

As the least serious or least significant of the three escalation levels of the emergency operation strategy, it is proposed that if the electronic control unit of the automatic transmission detects a fault in which restricted operation of the automatic transmission with at least some of the gear changes possible in normal operation of the automatic transmission is still possible, as a measure Triggering an error-specific predefined replacement function is defined, which is implemented in the electronic control unit of the automatic transmission. Activation and execution of this substitute function are done by the electronic control unit of the automatic transmission. In this case, any actuation of a drive machine of the motor vehicle that is required for the automatic transmission is also initiated and possibly also monitored by the electronic control unit of the automatic transmission.

An automatic transmission for a drive train of a motor vehicle with several drive units for driving this automatic transmission, which has a transmission input shaft, a transmission output shaft, a separating clutch arranged in the power flow between the transmission input shaft and a drive shaft of a first of the drive machines, a gear change device arranged in the power flow between the transmission input shaft and the transmission output shaft, an electrohydraulic control unit for activating the separating clutch and gear change device, and an electronic control unit that communicates with the drive units in terms of data technology for activating the electrohydraulic control unit and in whose electronic control unit the emergency operating strategy according to the invention is implemented, is the subject matter of independent patent claim 14.

A motor vehicle operated with the emergency operation strategy according to the invention with a drive train comprising several drive machines and an automatic transmission that can be driven by these drive machines and whose transmission input shaft can be connected to a drive shaft of a first of these drive machines via a separating clutch is the subject of independent patent claim 15.

• 1 ein beispielhaftes Blockschaltbild eines Kraftfahrzeug-Antriebsstrangs mit einem von mehreren Antriebsmaschinen antreibbaren Automatgetriebe; und

The invention is explained in more detail below with reference to the figures. show:

• 1 an exemplary block diagram of a motor vehicle drive train with an automatic transmission that can be driven by a plurality of drive machines; and

1 an exemplary function flowchart for an emergency operation strategy according to the invention with three escalation levels graded according to error severity.

Below and with reference to the in 1 shown block diagram is first described in more detail an embodiment of a drive train of a modern motor vehicle with hybrid drive. The motor vehicle is provided with reference number 1 here, the drive train with reference number 2. This drive train 2 acting on a drive axle 3 of motor vehicle 1 comprises a total of (and by way of example) four different drive machines, of which the first drive machine 10 is designed as an internal combustion engine, whereas the second , Third and fourth prime mover 20, 50, 60 are all designed as electric motors. Furthermore, the drive train 2 includes an automatic transmission 30 of any type and an axle drive 40 assigned to the drive axle 3. A fuel tank 8 is provided in the motor vehicle 1 to supply energy to the internal combustion engine 10, and a high-voltage battery 5 to supply energy to the three electric motors 20, 50, 60. a low-voltage battery 4 for supplying energy to all other electrical consumers. The high-voltage power supply and the low-voltage power supply are electrically connected to one another via a DC/DC voltage converter.

The automatic transmission 30 can be driven selectively or in parallel by the internal combustion engine 10 and the electric motor 20 . For this purpose, a drive shaft 12 - also called a crankshaft - of the internal combustion engine 10 can be connected to a transmission input shaft 32 of the automatic transmission 30 via a separating clutch 34, whereas a drive shaft 22 - also called a rotor shaft - of the electric motor 20 is permanently connected to the transmission input shaft 32. In this case, the separating clutch 34 and the electric motor 20 can be structurally an integral part of the automatic transmission 30 , that is to say they can be arranged spatially within a housing of the automatic transmission 30 . The electric motor 50 as the third drive machine of the drive train 2 is constantly operatively connected with its drive shaft 52 to the crankshaft 12 of the internal combustion engine 10, here for example via a chain drive 54. The automatic transmission 30 can thus be driven in series by the internal combustion engine 10 and the electric motor 50.

The electric motor 60 as an additional fourth drive machine is assigned to the drive axle 2 of the motor vehicle 1 . For this purpose, a drive shaft of this electric motor 60 is constantly connected both to an input shaft of the axle drive 40 and to a transmission output shaft 33 of the automatic transmission 30 . In the usual way, there is a power flow between the transmission input shaft 32 and the transmission Output shaft 33 is provided with a gear change device 35 so that automatic transmission 30 can transfer the drive power from internal combustion engine 10 and electric motors 20 and 50 to drive axle 3 of motor vehicle 1 in discrete gear steps or continuously variable transmission, depending on the design of automatic transmission 30.

In the exemplary embodiment illustrated here, a separate electronic control unit 11, 21, 51, 61 is provided for each of the four drive machines 10, 20, 50, 60. The electronic control unit 11 of the internal combustion engine 10 is often referred to simply as the engine control unit. The electronic control unit 21 of the electric motor 20 is often also referred to as a hybrid control unit, even if the electric motor 20 is structurally integrated into the automatic transmission 30 . The electronic control unit 31 of the automatic transmission 30 is often referred to simply as the transmission control unit. This electronic control unit 31 is used for the situational activation of an electrohydraulic control unit 36 of the automatic transmission 30 , this electrohydraulic control unit 36 in turn controlling the separating clutch 34 and the gear change device 35 of the automatic transmission 30 . The corresponding control lines 9 are indicated in the block diagram as dashed lines, here for the sake of simplicity without distinguishing between hydraulic and electrical lines.

Since the electric motors 20, 50 and 60 in the present exemplary embodiment are all designed as high-voltage AC machines, there is a DC/AC voltage converter 23 between the respective electronic control unit 21, 51, 61 and the respective electric motor 20, 50, 60. 53, 63 electrically interposed. The electronic control unit 11 of the internal combustion engine 10 and the electronic control unit 31 of the automatic transmission 30 , on the other hand, are conventionally connected to the low-voltage power supply of the motor vehicle 1 .

It is essential that all of these electronic control units 11 , 21 , 31 , 51 , 61 can communicate with one another via a data bus 8 provided in the motor vehicle 1 . In addition to the usual exchange of measured variables, which are used functionally and individually by several of these electronic control units 11, 21, 31, 51, 61, this communication line also enables control tasks to be carried out according to the specifications of one of these electronic control units 11, 21, 31, 51 , 61 can be delegated to another of these electronic control units. The present invention makes use of this circumstance within the scope of the emergency operation strategy according to the invention.

Below and with reference to the in 2 The function flow diagram shown is now an embodiment of such an inventive emergency operation strategy for the in 1 shown drive train 2 described in more detail. Implemented as a software module in the electronic transmission control unit 31 , this emergency operation strategy is integrated into the functional sequence for controlling the separating clutch 34 and the gear change device 35 . Correspondingly, the starting point S1 in the flow chart shown in FIG.

The first method step V1 following the starting point S1 after successful initialization of the software designates the continuous processing of a conventional diagnostic module. For example, as part of this processing, all sensors, actuators, electrical and electronic components installed in the automatic transmission 30 are checked for proper functioning, the external signals read in by the software are checked for plausibility and each situational activation of the separating clutch 34 and gear change device 35 is checked for admissibility Tripping and proper execution Tripping is monitored.

In a first query A1 that follows method step V1 or is included in the continuous diagnosis in method step V1, it is checked whether or not there is a fault relevant to automatic transmission 30. If this is not the case, there is a return to the first method step V1, so that the continuous diagnosis is continued. If, on the other hand, a relevant error is detected in query A1, the method is now continued as an emergency operation strategy according to the invention, characterized by function block S2. The emergency operation strategy according to the invention knows three escalation levels staggered according to the severity of the error, namely “minor serious”, “moderate” and “severe”.

After the start of the emergency operation strategy according to the invention in function block S2, a second query A2 is carried out, in which it is checked whether the error detected in the first query A1 is a serious error that prevents safe opening of the separating clutch 34 or a differentiated one Drive of the automatic transmission 30 with the internal combustion engine 10 and the two electric motors 20, 50 prevented.

• Die Getriebediagnose hat erkannt, dass die Trennkupplung 34, die entsprechend dem in 1 dargestellten Antriebsstrang 2 im Kraftfluss zwischen der Kurbelwelle 12 des Verbrennungsmotors 10 und der Rotorwelle 22 des Elektromotors 20 angeordnet ist, nicht mehr richtig schließen kann, beispielsweise wegen verschlissenem Reibbelag. Als praktikable Reaktion auf diesen Einzelfehler wird nun die schadhafte Trennkupplung 34 geöffnet, um anschließend mittels des am Getriebeeingang angeordneten Elektromotors 10 rein elektrisch weiterfahren zu können. Tritt nun als zweiter Fehler ein elektrischer Kurzschluss in der Spannungsversorgung des elektrohydraulischen Steuergerätes 36 des Automatgetriebes 30 oder ein elektrischer Kurzschluss an dem im elektrohydraulischen Steuergerät 36 zur Ansteuerung des Trennkupplung 34 vorgesehenen elektrohydraulischen Steuerventils auf, führt dies hier automatisch zu einer hydraulischen Ansteuerung der Trennkupplung 34 in zum Kupplungsschließen führender Richtung. Diese Fehlerreaktion jedoch steht nicht nur in krassem Widerspruch zu der bereits ausgelösten Fehlerreaktion „Trennkupplung öffnen“, sondern verursacht auch einen unbeabsichtigten Wechsel vom rein elektrischen Betrieb zu einem parallel-hybridischen Betrieb, bei dem ja ein gleichzeitiger elektromotorischen und verbrennungsmotorischen Antrieb prinzipiell zulässig ist. Mit einer aus dem Stand der Technik bekannten Notbetriebsstrategie ist eine solche Fehlerkombination nicht zufriedenstellend beherrschbar.

An example of such a fatal error is the following:

• The transmission diagnosis has recognized that the separating clutch 34, which, in accordance with the in 1 Drive train 2 shown is arranged in the power flow between the crankshaft 12 of the internal combustion engine 10 and the rotor shaft 22 of the electric motor 20, can no longer close properly, for example because of a worn friction lining. As a practicable reaction to this individual error, the defective separating clutch 34 is now opened in order to then be able to continue driving purely electrically by means of the electric motor 10 arranged at the transmission input. If the second fault is an electrical short circuit in the voltage supply of the electrohydraulic control unit 36 of the automatic transmission 30 or an electrical short circuit in the electrohydraulic control valve provided in the electrohydraulic control unit 36 for actuating the separating clutch 34, this automatically leads to a hydraulic actuation of the separating clutch 34 in this case direction leading to clutch engagement. However, this error reaction is not only in stark contradiction to the error reaction that has already been triggered: "Open the separating clutch", but also causes an unintentional change from purely electric operation to parallel-hybrid operation, in which a simultaneous electric motor and combustion engine drive is permitted in principle. Such an error combination cannot be controlled satisfactorily with an emergency operation strategy known from the prior art.

Coming back to the functional flow chart shown in FIG. 1, if the presence of an error in the “serious” category is detected in the second query A2, the method or the emergency operation strategy according to the invention is continued with a second method step V2, in which the escalation level is set to “severe”. is set. According to the invention, in this escalation level “most serious” as a measure against the detected error is defined that all drive machines 10, 20, 50 acting on the transmission input shaft 32 are to be switched off as quickly as possible. In addition, a later restart of the drive machines 10, 20, 50 is prohibited until the error determined in query A2 is no longer present.

In addition, in the escalation level “severe” as an additional measure, a torque limitation for the drive machines 10, 20, 50 effective in the switch-off phase can be defined in order to reduce the torque load on the separating clutch 34 immediately.

Correspondingly, in a third method step V3 following the second method step V2, all the measures taken in the previous method step V2 are encoded as a transmission message and fed into the data bus 8 of the motor vehicle 1. This transmission message is addressed to the electronic control unit 21 of the electric motor 20, with the result that this control unit 21 decodes the transmission message and then initiates the measures required to protect the automatic transmission 30 and also monitors the execution of these specifications. If the control unit 21 assigned to the electric motor 20 does not have direct access to the internal combustion engine 10, the control unit 21 must transmit the command to switch off the internal combustion engine 10 and, if necessary, also the command to limit the torque on the drive shaft 11 of the internal combustion engine 10 to the (functional) electronic Control unit 11 of the internal combustion engine 10 delegate. The same applies mutatis mutandis to those measures that can only be carried out by the electronic control unit 51 of the electric motor 50 .

If, on the other hand, the second query A2 returns a negative result, i.e. if the error detected in the first query A1 cannot be assigned to the most serious escalation level of the emergency operation strategy, a third query A3 is carried out, in which it is checked whether the error detected in the first query A1 is correct error is a moderate error. A malfunction is considered to be a medium-severe fault here, although it causes a significant impairment of the full functionality of the automatic transmission 30 and, in particular, makes proper gear changes impossible, but does not endanger the separating clutch 34 . If such an error has currently been detected, the method is continued with a fourth method step V4, in which the escalation level is set to “moderately severe”. In this escalation level “moderately severe”, the measure against the detected error is defined as that a predefined emergency gear is to be engaged in the automatic transmission 30, in which the motor vehicle 1 can still be driven, albeit with severe restrictions. This emergency gear would also have to be engaged when a gear is later engaged in the automatic transmission 30 if the error determined in query A3 is still present.

In addition, in the "moderate" escalation level, a torque limitation for the drive machines 10, 20, 50 is defined as a supplementary measure in order to protect the torque-carrying components in the automatic transmission 30 - in particular the transmission input shaft 32 - from a torque peak when shifting into emergency gear on the one hand and the torque load of Automatic transmission 30 to reduce overall when driving in emergency gear.

Correspondingly, in a fifth method step V5 following the fourth method step V4, all the measures taken in the previous method step V4 are encoded as a transmission message and fed into the data bus 8 of the motor vehicle 1. This message is addressed, for example, both to the electronic transmission control unit 31 itself and to the electronic control unit 21 of the electric motor 20 in such a way that the electronic transmission control unit 31 initiates the shifting of the gear change device 35 into the predefined emergency gear, whereas the electronic control unit 21 initiates the of the automatic transmission 30 necessary torque limitations for the various drive machines 10, 20, 50 initiated and optionally also monitored.

If, on the other hand, the third query A3 returns a negative result, i.e. if the error detected in the first query A1 cannot be assigned to the medium or moderately severe escalation level of the emergency operation strategy, a fourth query A4 is carried out, in which it is checked whether the error in the The error detected in the first query A1 is a minor error. A less serious error is a malfunction that impairs the functionality of the automatic transmission 30 but allows a limited operation of the automatic transmission 30 with at least some of the gear changes that are possible in normal operation. If such an error has currently been detected, the method is continued with a sixth method step V6, in which the escalation level is set to “less serious”—equivalent to “least significant”. In this escalation level "less severe" is defined as a measure against the detected error that in the automatic transmission 30 a replacement function tailored to the detected error, which is implemented together with other error-specific predefined replacement function in the software of the electronic transmission control unit 31 provided for operating the automatic transmission 30 , is to be activated.

Correspondingly, in a seventh method step V7 following the sixth method step V6, the measure taken in the previous method step V6 is encoded as a transmission message and—for purely informative purposes—fed into the data bus 8 of the motor vehicle 1 . The content of this transmission message is primarily addressed to the electronic transmission control unit 31 itself. In the present case, the error-specific replacement function required to protect the automatic transmission 30 is activated and processed by the electronic transmission control unit 31 . In this case, any activation of the internal combustion engine 10 and the electric motors 20, 50 that is required for the automatic transmission 30 is still initiated by the electronic transmission control unit 31 and, if necessary, also monitored.

If, on the other hand, the fourth query A4 returns a negative result, i.e. if the error detected in the first query A1 cannot be assigned to the smallest or less serious escalation level of the emergency operation strategy, the previously detected error does not require any further attention or no longer exists in the meantime. For this reason, the method is continued with a ninth method step V9, in which any data that may have had to be temporarily stored as part of the previous queries A1 to A4 is deleted. Then there is a return to the first method step V1, so that the continuous diagnosis is continued.

Starting from the processing of method steps V3, V5 and V7, ie after the respective measures corresponding to the respective escalation level have been implemented by the control units responsible for them, the method or the emergency operation strategy is continued with an eighth method step V8. This method step V8 marks the start of an error reverse filtering whose parameters are error-specifically predefined. Correspondingly, in a fifth query A5 following method step V8, whether the error previously determined in the first query A1 is currently still considered relevant. If the result of the query is positive, the error-specific error back-filtering has not yet been processed, which is why there is a return to query block A5. A return to normal operation of the automatic transmission 30 is only possible if the result of query A5 is negative.

Correspondingly, if the result of query A5 is negative, the method is continued with a function block S3, which marks the end of the emergency operation strategy and at the same time the transition to normal operation of automatic transmission 30, before the method is continued with the ninth method step V9 already described, followed by the jump back before the diagnostic method step V1.

Overall, the in 2 The proposed procedure for the emergency operation strategy according to the invention, with appropriate maintenance of availability, provides the highest possible security for the automatic transmission 30, including the separating clutch 34 upstream of the automatic transmission 30 in the direction of the internal combustion engine 10, against progressive destruction after a fault has been detected in the automatic transmission 30 and/or on the separating clutch 34.

Reference List

1

motor vehicle

2

drive train of the motor vehicle

3

Drive axle of the motor vehicle

4

low-voltage battery

5

high-voltage battery

6

DC/DC voltage converter

7

fuel tank

8th

data bus

9

control line

10

first prime mover; internal combustion engine;

11

electronic control unit of the first drive machine

12

Drive shaft of the first prime mover; Internal combustion engine crankshaft

20

second prime mover; electric motor

21

electronic control unit of the second drive machine

22

drive shaft of the second prime mover; Rotor shaft of the electric motor

23

DC/AC voltage converter of the second drive machine

30

automatic transmission

31

electronic control unit of the automatic transmission

32

transmission input shaft

33

transmission output shaft

34

disconnect clutch

35

gear change device

36

electrohydraulic control unit of the automatic transmission

40

final drive

50

third prime mover

51

electronic control unit of the third drive machine

52

Drive shaft of the third prime mover

53

DC/AC voltage converter of the third drive machine

54

chain drive

60

additional prime mover

61

electronic control unit of the additional drive machine

62

Drive shaft of the additional drive machine

63

DC/AC voltage converter of the additional drive machine

S1

function start; Initialization of the software in the electronic control unit of the automatic transmission

S2

Start of the emergency operation strategy

S3

End of the emergency operation strategy

A1

first query; detection of an error

A2

second query; Detection of a fatal error

A3

third query; Medium error detection

A4

fourth query; Detection of a minor error

A5

fifth query; Error reset detection

V1

first process step; diagnosis

v2

second process step; Set the most serious escalation level

V3

third process step; Addressing the measures to engine control

V4

fourth process step; Setting the middle escalation level

V5

fifth process step; Addressing of the measures differentiated at transmission control and engine control

V6

sixth process step; Set the smallest escalation level

V7

seventh process step; Addressing the measures to transmission control

V8

eighth process step; Start error back filtering

V9

ninth method step; data erasure

QUOTES INCLUDED IN DESCRIPTION

This list of the documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 10111830 A1 [0003, 0004]
• EP 0316358 B1 [0003, 0005]
• EP 1431626 A1 [0003, 0005]
• DE 19858540 A1 [0003, 0006]

Claims (15)

Emergency operation strategy for a drive train (2) of a motor vehicle (1) comprising a plurality of drive units (10, 20, 50) and an automatic transmission (30) which can be driven by these drive units (10, 20, 50), wherein in the power flow between a drive shaft (12) one A separating clutch (34) is arranged between the first drive machine (10) and a transmission input shaft (32) of the automatic transmission (30), the separating clutch (34) and a gear change device (35) of the automatic transmission (30) being controlled by an electrohydraulic control unit (36) of the automatic transmission (30) are activated on the basis of specifications from an electronic control unit (31) of the automatic transmission (30), with the electronic control unit (31) of the automatic transmission (30) monitoring the activation of the separating clutch (34) and gear change device (35) with regard to admissibility and proper implementation and reacts situationally in the event of an error, characterized in that the electronic control unit (31) of the automatic transmission es (30) in the event of an error, a transmission message dependent on an error severity is generated and transmitted to other electronic control units (11, 21) in the motor vehicle (1), measures being defined in this transmission message which, depending on the error severity, are sent by different electronic control units (11, 21 , 31) are to be processed. emergency operation strategy claim 1 , characterized in that the first drive machine (10) is designed as an internal combustion engine, whereas the second drive machine (20) is designed as an electric motor, the drive shaft (22) of which is constantly connected or operatively connected to the transmission input shaft (32) of the automatic transmission (30). emergency operation strategy claim 1 or 2 , characterized in that the drive train (2) has a third drive machine (50), which is designed as an electrical machine, the drive shaft (52) of which is either permanently connected or operatively connected to the drive shaft (12) of the first drive machine (10), or but can be connected or operatively connected to the drive shaft (12) of the first drive machine (10). emergency operation strategy claim 1 , 2 or 3 , characterized in that the drive train (2) has an additional drive machine (60), which is designed as an electric machine whose drive shaft (62) is constantly connected or operatively connected to a transmission output shaft (33) of the automatic transmission (30). Emergency operation strategy according to one of Claims 1 until 4 , characterized in that the emergency operation strategy has three escalation levels graded according to error severity. emergency operation strategy claim 5 , characterized in that the most serious escalation stage is when the electronic control unit (31) of the automatic transmission (30) detects a serious error in the separating clutch (34) or in the actuation of the separating clutch (34), which means that the separating clutch (34 ) prevented, as a measure a shutdown of all drive machines (10, 20, 50) of the automatic transmission (30) is defined. emergency operation strategy claim 5 , characterized in that the most serious escalation level is when the electronic control unit (31) of the automatic transmission (30) detects a serious error that prevents a differentiated drive of the automatic transmission (30) with the drive machines (10, 20, 50), as a measure a switching off of all drive machines (10, 20, 50) of the automatic transmission (30) is defined. emergency operation strategy claim 5 , 6 or 7 , characterized in that the execution of all measures defined in the most serious escalation level is initiated by an electronic control unit which is assigned to at least one of the drive units (10, 20, 50, 60) of the motor vehicle (1). emergency operation strategy claim 2 and 8th , characterized in that the execution of all measures defined in the most serious escalation level is initiated by an electronic control unit (21) of the second drive machine (20). Emergency operation strategy according to one of Claims 5 until 9 , characterized in that as a medium-severe escalation level, when the electronic control unit (31) of the automatic transmission (30) detects a medium-severe error in which limited operation of the automatic transmission (30) is still possible without changing gear, the action is to engage a predefined emergency gear is defined in the automatic transmission (30). emergency operation strategy claim 10 , characterized in that the execution of the engagement of the emergency gear is initiated by the electronic control unit (31) of the automatic transmission (30), whereas each control of a drive machine (10, 20, 50, 60) of the Motor vehicle (1) by an electronic control unit ini is tiated, which is associated with at least one of the drive machines (10, 20, 50, 60) of the motor vehicle (1). emergency operation strategy claim 2 and 11 , characterized in that every control of a drive machine (10, 20, 50, 60) required for the automatic transmission (30) is initiated by the electronic control unit (21) of the second drive machine (20). Emergency operation strategy according to one of Claims 5 until 12 , characterized in that as a minor escalation level when the electronic control unit (31) of the automatic transmission (30) detects an error in which a restricted operation of the automatic transmission (30) with at least some of the gear changes possible in normal operation of the automatic transmission (30) is still possible is possible, the triggering of an error-specific, predefined replacement function is defined as a measure, which is implemented in the electronic control unit (31) of the automatic transmission (30), with activation and execution of this replacement function being handled by the electronic control unit (31) of the automatic transmission (30). , and wherein every control of a drive motor (10, 20, 50, 60) of the motor vehicle (1) that is required for the automatic transmission (30) is also initiated by the electronic control unit (31) of the automatic transmission (30). Automatic transmission for a drive train (2) of a motor vehicle (1) with several prime movers (10, 20, 50) for driving this automatic transmission (30), which has a transmission input shaft (32), a transmission output shaft (33), a transmission in the power flow between the transmission input shaft (32 ) and a drive shaft (12) of a first of the drive machines (10) arranged separating clutch (34), a gear change device (35) arranged in the power flow between the transmission input shaft (32) and the transmission output shaft (33), an electrohydraulic control unit (36) for controlling the separating clutch ( 34) and gear change device (35) and an electronic control unit (31) for activating the electrohydraulic control unit (36), the electronic control unit (31) communicating with the drive units (10, 20, 50) in terms of data technology, characterized in that in the Electronic control unit (31) an emergency operation strategy according to one of Claims 1 until 13 is implemented. Motor vehicle with a drive train (2), comprising several drive machines (10, 20, 50) and an automatic transmission (30) which can be driven by these drive machines (10, 20, 50), the transmission input shaft (32) of which has a drive shaft via a separating clutch (34). (12) a first of these drive machines (10) can be connected, characterized in that the motor vehicle (1) with an emergency operation strategy according to one of Claims 1 until 13 is operated.

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