DE10160308A1 - Method for operating a drive train having a multiple clutch device and a powershift transmission and such drive train with corresponding control unit - Google Patents

Abstract

A method for operating a drivetrain and a drivetrain (10) with a controller (36), carrying out said method are disclosed. According to one aspect of the invention, at least in one operating state, from a driving operating state, or an overrun operating state for the drivetrain, on switching between a first speed with a first gearbox input shaft (20; 22) and a second speed with a second gearbox input shaft (22; 20), a clutch device (26; 28) on the first gearbox input shaft and a clutch device (28; 26) on the second gearbox input shaft are operated and a torque generation device (12, 50), comprising a drive unit (12) is controlled, such that, at least one of the following criteria is met with relation to a switching process comprising said switching: 1) during the switching process an at least approximately constant or monotonically changing torque is exerted on the gearbox output shaft, 2) during the switching process an essentially monotonically increasing or monotonically decreasing vehicle acceleration is achieved.

Description

The invention relates to a method for operating a motor vehicle The powertrain belonging to it, which has: a torque generator supply arrangement, the at least one drive unit, optionally in Form of an internal combustion engine, and, if desired, an auxiliary unit includes to generate an auxiliary torque; a synchronizer gearbox (especially powershift transmission) with little at least two transmission input shafts and at least one transmission output shaft, wherein a first transmission input shaft at least a first Gear and a second transmission input shaft at least a second Gear is assigned; one between the drive unit and the transmission arranged multiple coupling device, possibly double clutch lungseinrichtung, for torque transmission between the drive unit and the transmission, which is assigned to the first transmission input shaft first clutch arrangement and one of the second transmission input shaft has assigned second clutch arrangement, the two Coupling arrangements can be actuated independently of one another.

Such a method is known from DE 196 31 983 C1. The in the method disclosed in this patent was based on the objective of when switching completely without intervention in management (engine management) get by the internal combustion engine, so its power actuator at Switching does not affect. The procedure should also enable as far as possible without internal synchronization of the transmission come. According to this approach, a gearbox that is only suitable for be  correct gear types an internal synchronization of the transmission required, whereas synchronization is required for other circuit types to a certain extent is achieved externally by means of the coupling device.

The method of DE 196 31 983 C1 requires that we do this on the output kend torque is not constant during the switching process. here can lead to unwanted intermediate acceleration processes or Intermediate decelerations occur during the switching sequence. The The result is a loss of comfort for the driver and the vehicle occupants during the switching process.

In contrast, the invention proposes to ensure a high Comfort for the driver and vehicle occupants before that at least an operating state of a train operating state and a pushing Operating state of the drive train or the motor vehicle in the scarf the clutch between a first gear and a second gear arrangements actuated in this way and the torque generation arrangement in such a way controlled that at least one, preferably several or - most preferably - all of the following criteria related to one of those Switch comprehensive switching sequence are fulfilled: a) during switching sequence occurs on the transmission output shaft or on the output side thereof a transition phase a monotonously changing, at least partially transmitted from the transmission to the transmission output shaft, to the vehicle in the In the sense of an acceleration or deceleration preferably a difference between a momentary value at the on start of the transition phase and a momentary value at the end of the transition phase essentially a change in gear ratio at the Shifting corresponds, b) that remains on the gearbox during the shift sequence output shaft or on the output side of the same, at least partially mediated from the transmission to the transmission output shaft and essentially constant after the transition phase, c) during the Shaft drain is essentially via the transmission input shafts  constant, temporarily a sum of one over the first Transmission input shaft initiated first moment contribution and one second moments introduced via the second transmission input shaft corresponding transmission input torque is introduced into the transmission, d) an essentially monotonous increase occurs during the switching sequence vehicle acceleration, which decreases substantially or monotonously reached.

When above and in the following one speaks of monotonically increasing (monotonically increasing) or monotonously decreasing (monotonously decreasing), "monotonously increasing / increasing" means that the relevant size remains constant or increases, and means "monotonically decreasing / decreasing" that the size in question remains constant or falls. These terms have their meanings known from mathematics:
A function f is called monotonically falling (increasing) if for all x ₁ , x ₂ from (a, b] with a ≦ x ₁ <x ₂ ≦ b:

f (x ₁ ) / f (x ₂ ) (f (x ₁ ) ≦ f (x ₂ )).

The terms "strictly monotonically increasing / increasing" and "strictly monotonically decreasing / decreasing" are used in a corresponding manner, as is the case in mathematics:
The function f in [a, b] is called strictly monotonically falling (increasing), if for all x ₁ , x ₂ from [a, b] with a ≦ x ₁ <x ₂ ≦ b:

f (x ₁ ) <f (x ₂ ) (f (x ₁ ) <f (x ₂ )).

The term "continuous" used in the following is also intended to derive from the Mathematics have a well-known meaning.  

According to the proposal of the invention it is provided, for example, that an active intervention in engine management or an active influencing the power actuator of the drive unit (possibly internal combustion engine machine) and, if necessary, by activating the auxiliary accordingly aggregates the Mo given by the torque generation arrangement ment (possibly engine torque) is controlled so that on the output Torque fluctuations that occur due to forced acceleration and deceleration processes of the engine and / or the transmission gangswelle (generally as a result of forced positive and negative Acceleration processes) are compensated. Through this compensation tion is the goal of a monotonically increasing or monotonously falling longitudinal acceleration achievable.

This is preferably at least one criterion when shifting up from one lower gear (exit gear) to a higher gear (target gear) fulfilled. It is further preferred that the at least one criterion is when down shift from a higher gear (output gear) to a lower one Gear (target gear) is fulfilled. Is it the exit aisle? a first gear, the target gear is a second gear. It is the exit gear by a second gear, the finish gear is a first Gear.

According to a preferred implementation, this is at least one criterion fulfilled both in the train operating state and in the overrun operating state.

It is suggested that the switching sequence be done before inserting the target gangs an actuation of the clutch arrangement assigned to the target gear in the sense of extensive or complete disengagement. In front or / and while the target gear is engaged, the shift sequence can be a Actuation of the clutch arrangement assigned to the output gear in Meaning of a reduction in what can be transmitted by the clutch arrangement Include moments. For this purpose, it is further developed that in the  Train operating state the Mo transferable from the clutch assembly ment is set to a value that is about the current or before based on the Mo generation arrangement provided ment corresponds. Regarding the overrun operating condition is continuing education suggested that in the overrun mode, that of the clutch arrangement transferable torque is set to a value that in terms of amount less than the current or previous of the moments generation arrangement provided moment.

The switching sequence can be before or / and during or / and after insertion the target gear a control of the torque generation arrangement in Meaning an increase or decrease in one of the moments Provide arrangement provided torque.

In order to meet the highest comfort requirements, it can be provided that a moment contribution due to one in the course of inserting the target gear occurring acceleration or deceleration of a rotating mass arrangement compensation is compensated by setting an appropriate compensation tion torque contribution of the torque generation arrangement or / and by corresponding actuation of those assigned to the exit gear Clutch arrangement.

For the "rearrangement" of the torque to be transmitted from one coupling arrangement for the other clutch arrangement is proposed that the clutch arrangement assigned to the output gear into one Slip state is brought and then the one already inserted Target gear assigned clutch arrangement in the sense of a clutch and the clutch arrangement assigned to the output gear in the sense of a Disengaging is actuated. The clutch is preferably actuated Arrangements coordinated with each other, such that one of the coupling Total transmitted moment essentially  remains constant. This can take place, for example, in that a selected slip speed is kept constant.

With this "rearrangement" of the moment to be transmitted, the Target gear assigned clutch arrangement controlled in the sense of the one be engaged and the clutch assigned to the exit gear Regulation arrangement are operated in the sense of disengaging. Alternatively, the clutch arrangement assigned to the output gear can be used controlled in the sense of disengaging and the target gear assigned clutch arrangement regulated in the sense of engaging be operated.

The transfer of the moment to be transferred from one to the other Transmission input shaft due to the described actuation of the clutch Arrangements (one speaks of a so called "overlap circuit") has a corresponding change of the torque occurring at the transmission output shaft, since the Gear ratio in the output gear and the gear ratio in Finish are different from each other. In the "overlap scarf tion phase "is initially the gear ratio of the output gear is decisive and at the end of the "overlap switching phase" Gear ratio of the target gear is decisive. In the course of the overlap to a certain extent a smaller and smaller contribution the gear ratio of the output gear and a growing one Contribution of the gear ratio of the target gear to the total Transmission output shaft transmitted torque. You can probably from a continuously changing in the overlap switching phase speak "effective translation" of the gearbox, at least together hang with the transmission of the total on the transmission input shafts torque applied to the transmission output shaft and the result torque transformation corresponding to the effective transmission translations.  

Regarding the train operating state, it is proposed that in the train Operating status in the course or after a setting of the by the Target gear associated clutch arrangement transmissible torque a value that is approximately equal to that of the moment or prior to the moment provided moment corresponds to the moments ten generation arrangement in the sense of a lowering of this ready Set torque is driven to a speed of the moments generation arrangement to a speed of the assigned to the target gear At least approximate the transmission input shaft.

Regarding the overrun operating state, it is proposed that in the Thrust operating condition in the course or after an adjustment of the by the transmissible torque associated with the target gear clutch arrangement to a value that is approximately equal to that currently or preceding the Torque generation arrangement provided torque corresponds to that Torque generation arrangement so controlled and / or the Target gear assigned clutch assembly is operated such that the torque that can be transmitted by this clutch arrangement is larger in magnitude is provided as one of the torque generation arrangement at the same time set torque to a speed of the torque generation arrangement a speed of the transmission input shaft assigned to the target gear at least approximate.

To meet particularly high comfort requirements, it can be provided that that a moment contribution due to one in the course of the approximation of the Acceleration or deceleration of a rotational speed Senanordnung is compensated, if necessary by setting a corresponding compensation moment contribution of the moment generator supply arrangement.

In general, it will be useful that in the course of or after the proximity tion of the speed of the torque generation arrangement to the speed of the  gearbox input shaft assigned to the target gear to the target gear ordered clutch assembly essentially fully engaged becomes. At the latest when this coupling process is completed, the "Um storage "of the torque to be transmitted from the one clutch assembly ended to the other clutch assembly.

To be defined for a subsequent switching operation and with regard to the objective of creating advantageous conditions can be in the course of or after the approximation of the speed of the torque generation arrangement the speed of the transmission input shaft assigned to the target gear clutch arrangement assigned to the output gear at least so far be engaged that a speed assigned to the output gear Neten transmission input shaft to the speed assigned to the target gear Neten transmission input shaft is at least approximated. Here, For example, if high comfort requirements are to be met, a moment contribution due to a occurring in the course of the approximation of the speeds Compensate acceleration or deceleration of a rotating mass arrangement be adjusted by setting a corresponding compensation torque contribution of the torque generation arrangement.

As a rule, it will be advisable that in the course of or after the Annä Production of the speed of the torque generation arrangement to the speed the transmission input shaft assigned to the target gear generates the torque is controlled in such a way that it is ready for a moment represents that of the torque generation arrangement before switching process provided at least approximately corresponds. hereby are defined and advantageous with regard to the objective conditions created for a subsequent switching operation.

The torque provided by the torque generation arrangement can ready by the drive unit in at least one switching sequence phase provided momentary contribution and one provided by the auxiliary unit  Include moment contribution. Both contributions can be positive (e.g. in a train operating state) or both contributions can be negative (at for example in an overrun operating state) or it may be that a Post is positive and the other is negative. A negative moment contribution is usually applicable, can be described as drag torque NEN.

A crankshaft starter generator can advantageously be used as an auxiliary unit be applied. A brake arrangement (for example formed by the vehicle brakes or a separate auxiliary brake on a ge suitable location of the drive train) can be considered as an auxiliary unit. With reference to criterion a) according to the invention proposal it should be provided that the transition phase essentially from a Overlap circuit phase is formed, in which the clutch arrangement Openings can be operated in opposite directions to one between the drive unit and the torque to be transmitted from the output gear assigned transmission input shaft to that assigned to the target gear Shift transmission input shaft. The length of the transition phase and the change in the vehicle's longitudinal acceleration or driving therein tool deceleration, i.e. the acceleration or deceleration gradient in the transition phase, is an essential factor for driving comfort Vehicle occupants, since the acceleration or deceleration changes as changes in the inertia acting on the vehicle occupants express forces. A gradual change in a vehicle occupant, if necessary, the driver, acting inertia can by this can be easily compensated for by appropriate muscle work therefore not reducing comfort. Such inertial forces or changes of the inertia forces acting on the vehicle occupants Accelerate or decelerate or a change in acceleration or delay expected to a certain extent.  

This can, for example, provide sufficient driving comfort achieved that the transition phase lasts about 700 ms. Gegebe otherwise, the duration of the transition phase will be affected by those concerned Make transmission gears (exit gear and target gear) dependent so that different lengths for the gear spread Transition phase depending on the exit course. For example, one can choose the lengths of the transition phases so that a delay or desired acceleration gradient is reached.

If the transition phase is essentially formed by the overlap switching phase, this means that the comfort requirement corresponds appropriate expansion of this phase over time is a comparatively large one Friction work for the coupling arrangements of the coupling device. in the This is usually the case with wet-running multi-plate clutches completely unproblematic, since this usually has a correspondingly large reibar be able to withstand without further ado, without the service life or Le life is significantly impaired.

In the case of dry-running clutch arrangements, such as the friction plate benbauart, such a, comparatively long duration of the over gangsphase (= overlap switching phase) a right large, if not too heavy a load on the clutch assembly gene mean, resulting in a correspondingly short service life or life duration would result. For dry running clutch assemblies should the overlap scarf in terms of service life phase should be as short as possible.

The relationship between load and life on the one hand and The length of the overlap switching phase becomes over following particularly clear: the on a double clutch on the over friction circuit occurring in principle, which is basically independent of the design dependent, can be the product of the transmitted moment and the slip  speed are specified (friction power = torque × slip speed). Which measured the service life in the case of the dry-running double clutch Frictional work, which is the determining factor, is therefore essentially proportional nal to the length of time of the overlap switching phase. The following applies: Friction work = friction power × Δt.

In the case of dry-running clutch arrangements, the result is Conflict of goals that with regard to the load or lifespan Overlap circuit phase should be as short as possible, but this is the goal of a smooth transition when shifting, that is The need for comfort conflicts. For a smooth transition because the overlap switching phase should be as long as possible, so a "jerk" when shifting the moment from one Ge drive input shaft to avoid the other transmission input shaft.

To resolve the conflict of objectives and / or to avoid thermal problems or to make it easier to control, especially for dry-blue fende coupling arrangements, but if desired also for wet blue fende clutch arrangements (for example, multi-plate clutch arrangement ) proposed that the transition phase essentially formed is from an overlap shift phase in which the clutch assembly Openings can be operated in opposite directions to one between the drive unit and the torque to be transmitted from the output gear assigned transmission input shaft to that assigned to the target gear Shift transmission input shaft, as well as from one of the overlap circuit phase preceding gradient phase and / or one of the Overlap circuit phase subsequent gradient phase in which a monotonous change in the torque acting on the vehicle, where applicable, the torque occurring at the transmission output shaft, is brought about by appropriate control of the torque generation arrangement and / or by appropriate actuation of the output gear or the target gear associated clutch assembly.  

Based on the knowledge that the from switching because of the Change in gear ratio resulting in change in drive moments or drag torque at the transmission output is known and thus starting from the momentary moment before the switching sequence End of the switching sequence occurring moment is known or can be determined (The same applies in principle to the effective longitudinal vehicle acceleration or vehicle longitudinal deceleration before and after the switching process) after the training proposal in particular proposed the ent speaking change in the vehicle's longitudinal acceleration or vehicle Longitudinal deceleration (or the corresponding change in torque on Gearbox output) not by itself during the overlap shift phase for a powershift transmission continuously changing Realize "effective" translation of the gearbox, but by others (additional) measures (including management intervention the drive unit (engine management) and / or a corresponding one Control of an auxiliary unit delivering an auxiliary torque or / and a corresponding actuation of the clutch arrangements) the effect To change the same drive torque or drag or braking torque that is inherent in the overlap shift phase Change in the longitudinal acceleration or deceleration of the vehicle is to a certain extent embedded in a preceding and / or subsequent change in longitudinal acceleration or deceleration by means of the additional measures, for example the intervention in the engine management or / and a corresponding control of the clutch arrangements. The result is an overlap circuit phase in time around a preceding and / or a subsequent gradients prolonged transition phase, which the vehicle occupants like felt a correspondingly long overlap switching phase becomes. So it becomes, so to speak, the one before and / or after "overlap circuit" including the following gradient phase simulated. If you take, for example, a transition phase length of 700 ms, for example the overlap  circuit phase have a length of, for example, 100 to 150 ms. in the For example, at least one accounted for about 550 to 600 ms Gradient phase, for example one of the overlap switching phase preceding gradient phase of length 400 to 500 ms and one of the Overlap circuit phase subsequent gradient phase of length 100 to 150 ms. For the reduction of the total friction work especially those periods of the transition phase should be possible be long in which there is no or minimal clutch slip. For example, one can precede the overlap switching phase outgoing gradient phase so that little or no Clutch slip occurs. It is then recommended that the overlap before the gradient phase as far as possible to expand.

It is pointed out that the further educational invention proposal is also of interest if - for example in the case of a wet-running Double clutch of the multi-plate design the load on the clutch arrangement Openings can be managed by appropriate cooling and the service life of the double clutch due to long overlap circuit phases would not be unduly impaired. By Reduction of the friction work, the heat input is lower, so that by applying the proposed invention the cooling oil circuit only for Removal of smaller amounts of heat would have to be designed, which and result in energy savings.

In the overlap shift phase, the clutch assemblies can now can be controlled in such a way that a strictly monotonous, preferably a steady, most preferably an at least approximately linear Change in the torque occurring at the transmission output shaft is enough. It is also proposed that the overlap circuit phase preceding gradient phase and / or in the Overlap circuit phase following the gradient phase  Torque generation arrangement so controlled and / or the Output gear or the clutch gear assigned to the target gear such is actuated that a strictly monotonous, preferably steady, supreme preferably an at least approximately linear change in the the vehicle acting, possibly on the transmission output shaft occurring moment is reached. For a particularly high driving com It is further proposed that the control or actuation is such that a strictly monotonous, preferably over the entire transition phase a steady, most preferably an at least approximately linear Modification of the effect on the vehicle, possibly on the transmission output shaft occurring torque is reached.

As already indicated, one can advantageously provide that the monotonous, preferably continuous and possibly strictly monotonous or linear Modification of the effect on the vehicle, possibly on the transmission output shaft in the overlapping scarf the previous gradient phase and / or in the transfer phase intersection circuit phase set subsequent gradient phase is based on a change in gear ratio change in gearbox output shaft resulting from shifting occurring moments. In this context, this is particularly important thought that the monotonous, preferably continuous and possibly strictly monotonous or linear change in the vehicle's possibly occurring at the transmission output shaft torque m the relevant gradient phase is set on the basis of a Torque target gradients or acceleration target gradients or / and a predetermined period of time for the overlap switching phase or / and a predetermined period of time for the gradient phase in question or / and a predetermined period of time for the transition phase or / and a gear ratio assigned to the output gear or / and one the gear ratio assigned to the target gear or / and one momentary drive torque or drag torque of the drive unit  or / and a desired drive torque or drag torque Drive unit.

The above, referring to the reduction of the friction work or thermi load on the clutch assemblies without significant comfort in principle, any loss-making proposals are already included in all of the above Switched types of switching (high-pull, high-push, back-pull, Back-thrust) applicable. The following are for these types of circuits made more specific further training proposals, which are only examples or preferred configurations are to be viewed and are in no way restrictive are to be interpreted.

Regarding the high-pull circuit type, it is proposed, for example, that when shifting up from a lower gear (output gear) to a higher gear (target gear) in the train operating state one from the An drive unit provided drive torque and / or that of the Output gear associated with clutch arrangement transmitted or via wearable moment in the pre-overlap phase gradient phase monotonous, preferably strictly monotonous, highest preferably linear, from an initial value to an intermediate value is lowered. It can be advantageous if in the overlap the switching phase provided by the drive unit moment of the intermediate value monotone, preferably strictly monotone, most preferably linear, is raised. Further education is featured suggest that the drive torque provided by the drive unit in the overlap switching phase to another intermediate value is raised above the initial value and preferably in the course the gradient phase following the overlap switching phase from the further intermediate value to an out if desired initial value brought at least approximately corresponding final value becomes. It can advantageously be provided that the drive unit provided drive torque in the of the overlap scarf  the subsequent gradient phase of the further intermediate value is first brought to a value below the initial value and then raised to the final value and / or that one of the Target gear assigned clutch arrangement transmitted or transfer real moment in the phase following the overlap circuit Gradient phase from the / an intermediate value at the end of the overlap first, monotonous, preferably strictly monotonous, most preferably linear, lowered, and then optionally is raised again, especially after that from the drive unit provided moment has reached the final value.

For example, regarding the down-pull circuit type, it is suggested that when shifting down from a higher gear (output gear) to a lower gear (target gear) in the train operating state one of the Drive unit provided drive torque and / or that of the Output gear associated with clutch arrangement transmitted or via wearable moment in the pre-overlap phase gradient phase monotonous, preferably strictly monotonous, highest preferably linear, from an initial value to an intermediate value is raised. It can advantageously be provided that in the Overlap circuit phase prepared by the drive unit set driving torque from the intermediate value monotonously, preferably strictly monotonous, most preferably linear, is lowered.

In a further development, it is proposed that the drive unit be ready set drive torque in the overlap shift phase another intermediate value is lowered below the initial value and preferably in the course of the overlap switching phase subsequent gradient phase from the further intermediate value to one if desired, correspond at least approximately to the initial value appropriate final value is brought. In this context, one can advantageously provide that a clutch assigned to the target gear  transferable or transferable moment in the transfer cutting circuit phase subsequent gradient phase from the / egg an intermediate value at the end of the overlap switching phase mono tone, preferably strictly monotonous, most preferably linear to one further intermediate value, possibly corresponding to the final value is raised, and then possibly further raised, ins especially after the moment provided by the drive unit has reached the final value.

For example, regarding the down-shift circuit type suggest that when shifting down from a higher gear (output gear) to a lower gear (target gear) in overrun mode drag torque applied by the drive unit in the overlap circuit phase from an initial value monotonous, preferably strictly monotonous, most preferably linear, to an intermediate value is reduced. It can advantageously be provided that the Drive unit applied drag torque in the course of the over intersection phase subsequent gradient phase of the Intermediate value first further reduced and then to a desired one the final value at least approximately corresponding to the initial value brought. Further training is proposed that one of the Target gear assigned clutch arrangement transmitted or transfer real moment in the phase following the overlap circuit Gradient phase from an intermediate value at the end of the overlap switching phase monotonous, preferably strictly monotonous, highly preferred point linearly to another, possibly the amount of the final value corresponding intermediate value is raised, and then if necessary is raised further, especially after that from the drive unit applied drag torque has reached the final value.

For example, regarding the high-overrun circuit type is suggested that when shifting up from a lower gear (output gear)  to a higher gear (target gear) in overrun mode one of the Drive unit applied drag torque in the overlap circuit phase preceding gradient phase monotone, preferably strictly monotonous, most preferably linear, from an initial value an intermediate value is reduced and / or that that of the off gearbox assigned clutch arrangement transmitted or transfer moment in the phase preceding the overlap switching phase Gradient phase monotonous, preferably strictly monotonous, most preferred wise linear, lowered from an initial value to an intermediate value becomes. This can be advantageous from that of the exit aisle orderly clutch assembly transferable moment in the gradien in terms of the amount of the phase below that applied by the drive unit Reduce drag torque.

The transition phase can advantageously be at least partially from a brake phase be formed in which a monotonous change to the vehicle acting moment is effected by appropriate actuation ei ner / the brake assembly of the vehicle, possibly on the wheels of the Vehicle brakes, preferably at least in one At least partial phase of the braking phase in coordination with an actuation one of the coupling arrangements. Referring to the training proposal for the "extension" of the overlap circuit phase by at least one gradient phase can, for example, that of Overlap circuit phase preceding gradient phase or / and the gradients following the overlap switching phase tenphase be at least partially formed by a braking phase.

In general, the main thought is that one in a pushing operation braking torque of the drive unit occurring in at least one Phase of the switching sequence by one of / the brake assembly of the Vehicle, preferably by one of the driving wheels effective vehicle brakes, applied braking torque  is at least partially substituted. By substituting the brake moments due to the replacement braking torque can be undesirable positive Accelerations or an unwanted temporary after let a vehicle deceleration be avoided, for example wise in connection with an active synchronization the target gear with the participation of the drive unit (possibly internal combustion engine ne).

In this context, it is also proposed that a sub stitution is provided such that i) matched the previous the braking torque of the drive unit introducing into the transmission, the Output gear assigned clutch arrangement in the sense of a Disengagement and ii) the brake assembly in the sense of generating the Replacement braking torque is actuated. This can advantageously be provided be that, at least initially, the equivalent braking torque from the previously transmit the clutch arrangement assigned to the output gear Essentially corresponds to a braking torque, this clutch arrangement as a result of actuation in the sense of disengagement preferably no more essential moment, or at least initially a total braking torque from the replacement braking torque and one of the clutch arrangement assigned to the output gear still over essentially the rest of the carried moment before that of the end gearbox associated clutch assembly transmitted braking torque equivalent.

In a further development, it is proposed that the equivalent braking torque be con is continuously reduced, coordinated with an actuation of the target gear assigned clutch arrangement in the sense of engaging and / or on a change in an instantaneous one provided by the drive unit Moments in the sense of reducing a positive momentary on drive torque of the drive unit or in the sense of an enlargement momentary braking torque of the drive unit. With regard to the one  The objectives set out above can reduce the replacement brake moments in such a way that it affects the vehicle as a whole kend braking torque due to the provided by the drive unit instantaneous moment and the instantaneous braking effect of the brakes arrangement changes monotonically, preferably strictly monotonously. In this Context, it is preferred that the equivalent braking torque correspond chend a continuous change in the coupling device torque introduced into the transmission due to the drive Unit provided torque is reduced and preferably then in Essentially disappears when the dome assigned to the target gear Development arrangement essentially completely or a predetermined Transmits braking torque of the drive unit.

In this context, it should be borne in mind that the driver during the Driving the brake pedal could slow the vehicle down. This could be due to falling engine speed or driving speed a thrust downshift may be required. This thrust downshift can brake-assisted according to the previous explanations respectively. Here, the braking torque can be compared to that previously braking torque set by operating the brake pedal or / and during an overlap shift phase (if provided) or an active synchronization can be further increased. The shift sequence then starts with the braking torque, so to speak even with a braking torque specified by the driver, so that after the "circuit" the braking torque may not be zero, son on the braking torque specified by the driver or that brake torque should be reduced that existed before the "switching".

With regard to the aforementioned relief of the synchronizer device or synchronizing devices of the gearbox especially for one manufacturer downshifting in a coasting mode is considered special before proposed that in the overrun mode in preparation for a  Downshifting from a higher gear (output gear) to one lower gear (target gear) in a preparation phase of the shift sequence the clutch arrangement assigned to the output gear essentially fully disengaged, the drive unit to provide a positi ven drive torque controlled and the assigned to the target gear Coupling arrangement in an acceleration torque transmitting corresponding to a partial engagement of the clutch assembly Partial engagement is brought in such a way that the assigned to the target gear Nete transmission input shaft through this clutch arrangement based on the positive drive torque together with the drive unit itself in the direction of a synchronous rotation assigned to the target gear number is accelerated. Regarding the insertion of the target gear is in this context specifically suggested that the finish then is engaged when the speed of the gearbox assigned to the target gear input shaft essentially reaches or reaches the synchronous speed corresponding to a predetermined threshold differential speed interval Has approached synchronous speed. A corresponding discharge results device of the synchronization device or synchronization devices of the Gearbox, without an interruption of traction or thrust refraction must be accepted.

As a rule, it will make sense, at the latest after the target has been inserted the drive unit in the sense of reducing the positive Ant Driving torque and the provision of a braking torque. The torque provided by the drive unit is preferably continuously changed until the braking torque provided a pre given value, possibly the value prevailing at the start of the switching sequence, has reached.

The retention of the tensile force or pushing force according to the invention is indeed from Comfort reasons always desirable. In certain situations you can but an interruption in thrust or traction also in  Terms of accepting the resulting loss of comfort to the Friction work on the coupling arrangements in an overlap scarf device or / and on the synchronizer or the synchronizer to limit or minimize equipment in the transmission. One can therefore provide that between the first and second train operating states a distinction is made, whereby for the first train operating states of the scarf between the first gear and the second gear in the sense of one Upshifting and / or in the sense of downshifting the clutch arrangements actuated in this way and the torque generation arrangement in such a way be controlled; that at least one of the criteria a) to d) is related on the switching sequence is fulfilled, and being for second train operating states without fulfilling at least one of the criteria a) to d) in With respect to the switching sequence, the switching sequence is carried out in such a way that an interruption in traction occurs. It can also be provided that a distinction is made between first and second thrust operating states, being for first overrun operating states when switching between the first gear and second gear in the sense of an upshift or / and in the sense of a downshift actuating the clutch arrangements in this way and the torque generation arrangement are controlled in such a way that at least one of the criteria a) to d) in relation to the switching sequence is satisfied, and being without second thrust operating states the fulfillment of at least one of the criteria a) to d) in relation to the Shift sequence The shift sequence is carried out in such a way that a thrust power interruption occurs.

The invention further relates to a drive train, possibly in a A motor vehicle comprising: a torque generation arrangement that at least one drive unit, possibly in the form of an internal combustion engine machine, and, if desired, an auxiliary unit for generating a Auxiliary torque includes; a synchronizing device Transmission (in particular powershift transmission) with at least two transmissions input shafts and at least one transmission output shaft, one  first transmission input shaft at least a first gear and a two te transmission input shaft is assigned to at least one second gear; a Mehr arranged between the drive unit and the transmission compartment coupling device, if necessary double coupling device, for torque transmission between the drive unit and the gearbox, the first clutch assigned to the first transmission input shaft arrangement and a second assigned to the second transmission input shaft Has coupling arrangement, the two coupling arrangements are independently operable. According to the invention, a Control unit assigned to the drive train, which is set up for this is in connection with switching between a first and a second course to maintain an at least approximately constant, mediated from the transmission to the transmission output shaft Moments on the transmission output shaft before and after a transition phase, in which a monotonous change from transmission to transmission gear wave mediated torque preferably correspond essentially after the change in gear ratio occurs when shifting, or / and to achieve a substantially monotonically increasing or essentially monotonically decreasing vehicle acceleration or / and the torque generation to achieve a desired driving comfort control arrangement according to the inventive method and the To actuate coupling device according to the inventive method gene.

As already mentioned, the auxiliary unit can be a crank Actuate shaft starter generator. You can also use a brake assembly possibly the vehicle brakes acting on the wheels of the vehicle, as Provide or use auxiliary unit. The clutch assemblies can advantageously be designed as wet-running multi-plate clutch arrangements leads. For example, a multiple coupling device, specifically double clutch device, thought as in different The applicant's patent applications are evident. It will particularly focus on  German patent applications 199 55 356.3 (AT November 17, 1999); 100 04 179.5, 100 04 186.8, 100 04 184.1, 100 04 189.2, 100 04 190.6, 100 04 105.7 (all AT 01.02.2000); 100 34 730.4 (AT 07/17/2000) referenced (see for example DE 100 04 179 A1), the disclosure of which in the disclosure content of the present application is included. at the coupling arrangements can also be dry-running Act clutch assemblies (e.g. friction disc type). It will be at for example on the double clutch disclosed in DE 35 26 630 A1 construction referenced.

The invention is illustrated below with reference to the figures clear embodiments explained in more detail.

Fig. 1 shows schematically a drive train which can be operated according to a method according to the invention and has a control unit which works according to a method according to the invention.

Fig. 2 is a diagram illustrating an example of a shift sequence according to the invention when shifting up under train operating conditions.

Fig. 3 is a diagram illustrating an example of a shift sequence according to the invention when downshifting under train operating conditions.

Fig. 4 is a diagram illustrating an example of a shaft drain according to the invention when shifting up under overrun conditions.

Fig. 5 is a diagram illustrating an example of a shift sequence according to the invention when downshifting under overrun conditions.

FIG. 6 schematically shows a modification of the drive train according to FIG. 1, according to which a dry-running double clutch of the friction disk type is provided instead of a wet-running multi-plate clutch.

Fig. 7 is a diagram illustrating another example of an inventive shift sequence when shifting up under train operating conditions.

Fig. 8 is a diagram illustrating another example of a shift sequence according to the invention when downshifting under overrun operating conditions.

Fig. 9 is a diagram illustrating another example of a shift sequence according to the invention when shifting down under train operating conditions.

Fig. 10 is a diagram illustrating another example of a switching sequence to the invention OF INVENTION when down-shifting under train operating conditions.

Fig. 11 to 14 are diagrams each illustrating another example of a switching sequence according to the invention when down-shifting under thrust operating conditions in which a brake-assisted active synchronization is provided.

Fig. 15 is a diagram illustrating another example of a switching sequence to the invention OF INVENTION when down-shifting under thrust operating conditions.

Fig. 1 shows an example of a drive train 10 of a motor vehicle. The drive train has a drive unit 12 in the form of an internal combustion engine, especially an internal combustion engine, as indicated by a crankshaft 14 drawn as a symbol. A so-called load shift transmission 18 with two radially shifted transmission input shafts 20 and 22 is connected to the motor 12 via a double clutch 24 . The double clutch 24 comprises two clutch arrangements 26 and 28 , one of which is assigned to the transmission input shaft 20 and the other to the transmission input shaft 22 . The exemplary embodiment is a wet-running multi-plate clutch arrangement which can be actuated hydraulically by means of a respective hydraulic slave cylinder (not shown) integrated in the double clutch. A corresponding hydraulic pump 30 is shown schematically. A cooling oil circuit associated with the double clutch with a cooling oil pump etc. is not shown. Suitable double clutch constructions are known for example from DE 100 04 179 A1.

The actuation of the two clutch arrangements takes place by means of control valves 32 and 34 , which can be controlled electrically by a control unit 36 . The control unit receives input signals from an accelerator pedal 38 , a gear selection or / and influencing unit 38 , a speed sensor 40 assigned to the transmission input shaft 20 , a speed sensor 42 assigned to the transmission input shaft 22 and a speed sensor 44 assigned to the engine output shaft (crankshaft 14 ). The control unit can also receive further signals and measured values from other sensors and signal generators, such as a vehicle speed sensor, a steering angle sensor, a brake actuation state sensor, etc.

By comparing the speed of the speed sensor 44 on the one hand and the speed of the speed sensor 40 or 42 on the other hand, the control unit can determine a slip state of the clutch arrangement 26 or the clutch arrangement 28 . The control unit 36 controls a power actuator of the engine 22 in order to adjust the power output or the engine output torque. The delivered torque can also be a negative torque (drag torque). According to a preferred embodiment of the drive train, this has, for example, an additional unit between the engine 12 and the double clutch 24 for generating a positive or negative torque. The additional unit can be, for example, a crank shaft starter generator, which on the one hand serves to start the engine and on the other hand can be used as a generator. In Fig. 1, a crankshaft starter generator 50 is shown, which has a stator arrangement arranged on the motor 12 and a rotor arrangement arranged on the input side of the double clutch 24 . The crankshaft starter generator 50 is activated by the control unit 36 in order to provide a positive or negative torque as required.

Regarding the powershift transmission 18 , it should also be noted that it is preferably a fully synchronized transmission with a corresponding synchronizing device 52 . The synchronizing device 52 does not need to be a central synchronizing device for the entire transmission. The synchronizing device can also be formed by conventional synchronizing means, for example in the form of synchronizing rings. An output shaft of the transmission is designated 54 .

In the following, exemplary switching sequences will now be explained with reference to FIGS . 2 to 5, which implement variants of an operating method according to the invention for a drive train, for example the drive train of FIG. 1. The switching sequences can be implemented, for example, with the intermediation of the control unit 36 by correspondingly controlling the drive unit 12 , the clutch arrangements 26 and 28 and - if appropriate - the auxiliary unit 50 , possibly as a function of parameters specified by the unit 38 . The switching sequences are preferably carried out fully automatically by the control unit 36 .

In the following explanations, reference is made to transmission input shafts 1 and 2, clutches 1 and 2 and gears 1 and 2. The transmission input shaft 1 can correspond to the shaft 20 and the transmission input shaft 2 can correspond to the shaft 22 , or vice versa. Accordingly, the clutch 1 of the clutch assembly 26 and the clutch 2 can correspond to the clutch assembly 28 , or vice versa. Gear 1 is a gear assigned to the transmission input shaft 1 (the output gear) and gear 2 is a gear assigned to the transmission input shaft 2 (the target gear).

Switching sequence TRAIN-HIGH

Assumption: it is in a train operating state by a smaller one, the Gearbox input shaft 1 assigned gear 1 to a larger, the Gearbox input shaft 2 assigned to gear 2 switched.

With the pull-high switching mode, the motor delivers a positive torque to the Transmission. This moment is transmitted via the transmission input shaft 1. The Clutch 1 is connected to the transmission input shaft 1, clutch 2 to the Transmission input shaft 2. In the initial state, both clutches are complete closed and are therefore under pressure. Both As a result, transmission input shafts rotate at engine speed. On the Gearbox input shaft 1 is in gear and thus the frictional connection between the transmission input shaft 1 and the transmission output shaft manufactured.

A preferred switching sequence comprising five switching phases is explained below with reference to FIG. 2. The switching phases designated by the Arabic numerals 1 to 5 in FIG. 2 correspond to the following phases I to V. Possible variants and configurations of the switching phases are shown in dashed lines in FIG. 2 and are explained separately below as "alternatives" to the switching phase in question. To differentiate between the various curves and curve sections, these are identified by the identifiers N _Mo for engine speed, N _G1 for speed of gearbox input shaft 1, N _G2 for speed of gearbox input shaft 2, M _Mo for engine torque, M _K1 for clutch 1 torque and M _K2 for clutch torque 2 provided. An additional contribution to the changes in the speeds resulting from the positive longitudinal acceleration and representing the change in the vehicle speed is not taken into account in the partial diagram for the speeds. Furthermore, for the sake of simplicity, it was assumed that the engine torque remained constant over the engine speed (without active intervention in the engine control system). The switching process calculated from the beginning of switching phase 1 to the end of switching phase 5 could, for example, take about 0.5 to 1 seconds.

Phase I

In initiating the switching process, clutch 2 is opened completely.

Phase II

The clutch torque of clutch 1, M _K1 , is reduced to the current engine torque, M _Mo0 . In addition, a gear is engaged on the transmission input shaft 2 which is higher than the gear engaged on the transmission input shaft 1. By means of the synchronization device of the transmission, this leads to a drop in the speed of the transmission input shaft 2 to the synchronous speed corresponding to the gear engaged.

Phase III

The engine torque is briefly increased by appropriate intervention in the engine management via the clutch _torque of clutch 1, M _K1 = M _Mo0 , which leads to an increase in engine speed via the speed of transmission _input shaft 1 and accordingly to clutch 1 slipping. In order to prevent a further increase in the engine speed, the engine torque is reduced again to the original engine torque M _Mo0 . The slip state is maintained due to a resulting equilibrium of moments.

The clutch 1 is thus in slip and a selected slip speed (for example a differential speed of approximately 10-20 rpm) is adjusted via the clutch 1. After reaching the selected slip speed of clutch 1, clutch 2 is closed in a controlled manner. The clutch 1 is regulated in such a way that the selected slip speed is retained. As a result, the controlled closing of the clutch 2 causes the clutch 1 to open in a controlled manner, since the previously selected slip speed can only be kept constant if the sum of the moments MK ₁ + MK ₂ , that of the two clutches on the transmission input shafts and thus - with mediation of the transmission - is transmitted to the transmission output shaft, is constantly equal to the selected engine torque.

M _K1 + M _K2 = M _Mo0

The clutch 2 takes on more and more engine torque until the clutch 1 is fully opened. The clutch 2 can now transmit the complete engine torque, M _Mo0 , and is no longer closed.

Phase IV

Since the engine and thus also the engine-side half of clutch 2 rotates at gearbox input shaft 1 + slip speed, but the gearbox-side half of clutch 2 rotates at gearbox input shaft 2 speed, an active lowering of the engine torque to M _Mo1 below clutch _torque M _K2 = M _Mo0 (ie through an appropriate intervention in the engine management) the engine speed down to the speed of the transmission _input shaft 2. Braking the engine brings additional torque,

which is from the energy stored in the flywheel of the engine,

comes on the transmission input shaft 2 and thus on the transmission output shaft.

The total torque applied to the transmission output shaft corresponds to the transmissible torque of clutch 2 without taking into account a transmission factor caused by the gear ratio effective in the target gear and is composed as follows:

Mo1 + M _RotMot = M _Mo0

The reduction in the engine torque corresponds to the torque contribution due to the braking of the engine. This means that no additional torque is applied to the transmission output shaft when the engine is braking. As indicated, the gear ratio has not yet been taken into account in the above torque equation. Strictly speaking, M _{Mo0 is} the torque transmitted to the transmission _input shaft 2, which is only equal to the torque transmitted to the transmission output shaft in the case of a ratio 1: 1. For another gear ratio, a factor indicating the torque transformation due to the effective gear ratio has to be taken into account.

The fully opened clutch 1 now allows the on the Gearbox output shaft 1 gear engaged virtually without torque exit.

Phase V

The clutch 2 is closed completely. The clutch 1 is closed, which leads to the speed N _{G1 of} the transmission _input shaft 1 falling to the level of the transmission input shaft 2. The engine torque is returned to the original value M _Mo0 .

Phase I (alternative)

It may be that the clutch 2 only so far before the start of the shift sequence it is concluded that the transmitted drag torque is sufficient, the Maintain transmission input shaft 2 at engine speed. At the engine control nothing changes during the entire switching process.

Phase II (alternative)

The engagement of a higher gear than that engaged on the transmission input shaft 1 now inevitably leads to a braking of the transmission input shaft 2. The energy gain associated therewith

would be additional torque with static, engine torque

bring on the transmission output shaft, which would lead to an undesirable intermediate acceleration of the vehicle. In order to prevent this intermediate acceleration process, the engine torque M _{Mo1 is} reduced during the synchronization process to _{such an} extent that the sum of the engine torque M _Mo1 and the transmission _input shaft torque M _{G2 of} the transmission input shaft 2 remains constant with the engine torque M _Mo0 before the synchronization process.

M _total = M _Mo0 = M _Mo1 + M _G2

As a rule, the momentary contribution will slow down due to the Gearbox input shaft 2 is only a small effect, so that Embodiment described here the compensation of this momentary contribution due to a corresponding reduction in engine torque, this is not a mandatory measure is.

Phase III (alternative)

If the current engine torque M _{Mo0 is} already equal to the maximum available engine torque M _max , the engine _torque cannot be raised above M _Mo0 through normal intervention in engine management.

In order to achieve the slip speed required for clutch control, the additional torque which exceeds M _max can be supplied by an OVERBOOST function of the engine and / or by an auxiliary unit, for example a crankshaft starter generator.
Or and:
The sum of the moments M _K1 + M _K1 , which is transmitted from the two clutches to the transmission output shaft, must remain below the selected engine torque M _Mo0 until the desired slip speed is reached:

M _K1 + M _K2 <M _Mo0 .

Or and:
It can also be provided that the differential speed of engine speed - transmission input shaft speed of the transmission input shaft 2 is defined as the slip speed and is regulated by clutch 2. The clutch 1 is then opened in a controlled manner. The clutch 2 is thus closed in a controlled manner.

Phase V (alternative)

The acceleration energy that is released when the transmission input shaft 1 is braked

can, as in phase II, by lowering the motor torque 87681 00070 552 001000280000000200012000285918757000040 0002010160308 00004 87562ents

compared to the original M _Mo0 level. The engine torque is then raised to the original level M _Mo0 .

As a rule, the moment contribution due to the braking of the transmission input shaft 1 is only a small effect, so that in the exemplary embodiment described here the compensation of this moment contribution by appropriate setting of the engine torque is not a mandatory measure.
Or and:
It can be provided that the clutch 1 is closed only to such an extent that its transmissible torque is sufficient to bring the transmission input shaft 2 to the speed of the engine.

Result

The entire course of acceleration during the coupling process runs monotonously without intermediate _deceleration or intermediate acceleration processes, since at any time essentially the moment M _Mo0 is introduced into the transmission by means of the transmission input shafts and is transmitted to the transmission output shaft in accordance with the transmission ratios in the output and target gears. Accordingly, an essentially constant (phases I, II, IV, V) or monotone (preferably strictly monotone, e.g. linear) falling (phase III) driving torque acts on the transmission output shaft at all times.

Switching sequence TRAIN-BACK

Assumption: it is in a train operating state by a larger one, the Gearbox input shaft 1 assigned gear 1 to a smaller, the Gearbox input shaft 2 assigned to gear 2 switched.

With the pull-return circuit type, the motor delivers a positive torque to the Transmission. This moment is transmitted via the transmission input shaft 1. The Clutch 1 is connected to the transmission input shaft 1, clutch 2 to the Transmission input shaft 2. In the initial state, both clutches are complete closed and are therefore under pressure. Both As a result, transmission input shafts rotate at engine speed.

A gear is engaged on the transmission input shaft 1 and thus is the Power shot between the transmission input shaft 1 and the Gearbox output shaft manufactured.

A preferred switching sequence comprising five switching phases is explained below with reference to FIG. 3. The switching phases denoted by the Arabic numerals 1 to 5 in FIG. 3 correspond to the following phases I to V. Possible variants and configurations of the switching phases are shown in dashed lines in FIG. 3 and are explained separately below as "alternatives" to the switching phase in question. To differentiate between the various curves and curve sections, these are identified by the identifiers N _Mo for engine speed, N _G1 for speed of gearbox input shaft 1, N _G2 for speed of gearbox input shaft 2, M _Mo for engine torque, M _K1 for clutch 1 torque and M _K2 for clutch torque 2 provided. An additional contribution to the changes in the speeds resulting from the positive longitudinal acceleration and representing the change in the vehicle speed is not taken into account in the partial diagram for the speeds. Furthermore, for the sake of simplicity, it was assumed that the engine torque remained constant over the engine speed (without active intervention in the engine control system). The switching process calculated from the beginning of switching phase 1 to the end of switching phase 5 could, for example, take about 0.5 to 1 seconds.

Phase I

In order to initiate the switching process, clutch 2 is opened completely.

Phase II

The clutch torque of clutch 1, M _K1 , is reduced to the engine torque M _Mo0 valid in phase I. In addition, a gear is engaged on the transmission input shaft 2 which is lower than the gear engaged on the transmission input shaft 1. By means of the synchronization device of the transmission, this leads to an increase in the speed of the transmission input shaft 2 to the synchronous speed corresponding to the gear engaged. The engine torque is thereby raised by corresponding intervention in the engine management as over, the transferable clutch torque M _K1 of the coupling 1 to a value M _MO1 that the differential moment M _slip = M _o1 - M _K1 leads to an increase in engine speed above the speed of the gearbox input shaft 2 ,

Phase III

After reaching the selected engine speed above the speed of the transmission input shaft 2, the engine torque is reduced again to the original torque M _{Mo0 in} order to prevent a further increase in the engine speed. The clutch 1 is in slip and the selected slip speed between the transmission input shaft 1 and the engine speed is adjusted by means of the clutch 1. The clutch 2 is closed in a controlled manner. This triggers a controlled opening of clutch 1, since the previously selected slip speed can only be kept constant if the sum of the moments M _K1 + M _K2 , that of the two clutches on the transmission input shafts and thus - through the transmission - on Transmission output shaft is transmitted, is constantly equal to the selected engine torque M _Mo0 .

M _K1 + M _K2 = M _Mo0

The clutch 2 takes on more and more engine torque until the clutch 1 is fully opened. The clutch 2 can now transmit the complete engine torque, M _Mo0 , and is no longer closed.

Phase IV

Since the engine and thus also the engine-side half of clutch 2 rotates at gearbox input shaft 2 + slip speed (between gearbox input shaft 2 and engine), but the gearbox-side half of clutch 2 rotates at gearbox input shaft 2, the engine torque is reduced to M _Mo2 under the clutch torque M _K2 = M _Mo0 , the engine speed is pulled down to the speed of the transmission _input shaft 2. Braking the engine brings additional torque,

which from the energy stored in the flywheel of the engine

comes on the transmission input shaft 2 and thus on the transmission output shaft. The total torque applied to the transmission output shaft corresponds to the transmissible torque of clutch 2 without taking into account a transmission factor caused by the gear ratio effective in the target gear and is composed as follows:

M _Mo1 + M _RotMot = M _Mo0

This means that no additional torque is applied to the transmission output shaft when the engine is braking. The gear ratio has not yet been taken into account in the above torque equation, but is only included in the form of a factor. Strictly speaking, M _{Mo0 is} the torque transmitted to the transmission _input shaft 2, which is only equal to the torque transmitted to the transmission output shaft in the case of a ratio 1: 1.

The fully opened clutch 1 now allows the on the Gearbox output shaft 1 gear engaged virtually without torque exit.

Phase V

The clutch 2 is closed completely. The clutch 1 is closed, which leads to the increase in the speed n1 of the transmission input shaft 1 to the level of the transmission input shaft 2. The engine torque is returned to the original value M _Mo0 .

Phase I (alternative)

It may be that the clutch 2 only so far before the start of the shift sequence it is concluded that the transmitted drag torque is sufficient, the Maintain transmission input shaft 2 at engine speed. At the engine control nothing changes during the entire switching process.

Phase II (alternative)

If the engine torque M _Mo0 valid in phase I is already equal to the maximum available engine torque M _max , the engine _torque cannot be raised above M _Mo0 by normal intervention in the engine management system.

In order to bring the engine speed above the speed of the transmission input shaft 2, the torque to be used, which exceeds M _max , can be supplied by an OVERBOOST function of the engine and / or can be supplied by an auxiliary unit, for example a crankshaft starter generator.
Or and:
The acceleration energy required to accelerate the transmission input shaft 2

at static engine torque, the torque experienced by the transmission output shaft would be around

reduce, which would lead to an undesirable negative intermediate acceleration of the vehicle. In order to prevent this intermediate acceleration process, the clutch 1 can be moved during the synchronization so that the clutch can transmit a torque corresponding to the sum of the original engine torque M _Mo0 and the transmission _input shaft torque of the transmission _input shaft 2 M _G2 :

M _K1 = M _Mo0 + M _G2

As a rule, the negative torque contribution due to the acceleration of the transmission input shaft 2 will be only a small effect, so that in the exemplary embodiment described here, the compensation of this torque contribution by appropriate adjustment of the clutch 1 is not a mandatory measure.
Or and:
The transmissible clutch torque M _K1 of clutch 1 is reduced below the engine torque M _Mo0 in this phase in order to achieve the slip _speed required for clutch control. In order to prevent a further increase in the engine speed, the clutch torque M _{K1 is raised} to the engine torque M _Mo0 after the desired engine speed has been reached.

Phase III (alternative)

Alternatively, the differential engine speed Gearbox input shaft speed of gearbox input shaft 2 as slip speed  be defined and adjusted by clutch 2. The clutch 1 will then open in a controlled manner and, as a result, clutch 2 is closed in a controlled manner.

Phase V (alternative)

The acceleration energy required to increase the speed of the transmission input shaft 1

can by increasing the engine torque by

on M _Mo3 = M _Mo0 + M _{G1 can be} compensated. The engine torque is then reduced again to the original level M _Mo0 .

As a rule, the negative torque contribution due to the acceleration of the transmission input shaft 1 will be only a small effect, so that in the exemplary embodiment described here, the compensation of this torque contribution by a corresponding increase in the engine torque is not a mandatory measure.
Or and:
It can be provided that the clutch 1 is closed only to such an extent that its transmissible torque is sufficient to bring the transmission input shaft 2 to the speed of the engine.

Result

The entire course of acceleration during the coupling process runs monotonously without intermediate _deceleration or intermediate acceleration processes, since at any time the torque M _Mo0 is introduced into the transmission by means of the transmission input shafts and is transmitted to the transmission output shaft in accordance with the transmission ratios in the output and target gears. Accordingly, an essentially constant (phase I, II, IV, V) or monotone (preferably strictly monotone, e.g. linear) increasing (phase III) driving torque acts on the transmission output shaft at all times.

SHIFT-HIGH switching sequence

Assumption: It is in a coasting mode from a smaller one, the Gearbox input shaft 1 assigned gear 1 to a larger, the Gearbox input shaft 2 assigned to gear 2 switched.

With the thrust-high switching mode, the motor delivers a drag torque to the Gearbox, which is referred to below as a negative torque.

This negative torque is transmitted via the transmission input shaft 1. The Clutch 1 is connected to the transmission input shaft 1, clutch 2 to the Transmission input shaft 2. In the initial state, both clutches are complete closed and are therefore under pressure. Both As a result, transmission input shafts rotate at engine speed. On the Gearbox input shaft 1 is in gear and thus the frictional connection between the transmission input shaft 1 and the transmission output shaft manufactured.

A preferred switching sequence comprising five switching phases is explained below with reference to FIG. 4. The switching phases denoted by the Arabic numerals 1 to 5 in FIG. 4 correspond to the following phases I to V. Possible variants and configurations of the switching phases are shown in dashed lines in FIG. 4 and are explained separately below as "alternatives" to the switching phase in question. To differentiate between the various curves and curve sections, these are identified by the identifiers N _Mo for engine speed, N _G1 for speed of gearbox input shaft 1, N _G2 for speed of gearbox input shaft 2, M _Mo for engine torque, M _K1 for clutch 1 torque and M _K2 for clutch torque 2 provided. An additional contribution to the changes in the speeds resulting from the negative longitudinal acceleration (deceleration) and representing the change in the vehicle speed is not taken into account in the partial diagram for the speeds. Furthermore, for the sake of simplicity, it was assumed that the engine torque remained constant over the engine speed (without active intervention in the engine control system). The switching process calculated from the beginning of switching phase 1 to the end of switching phase 5 could, for example, take about 0.5 to 1 seconds.

Phase I

In order to initiate the switching process, clutch 2 is opened completely.

Phase II

The transferable clutch torque M _K1 is now brought below the current amount of the engine torque.

MK1 <| M _towing |

As a result, the engine speed falls below the speed of the synchronous speed of the transmission input shaft 2. The drag torque transmitted to the transmission input shaft 1 and thus to the transmission output shaft is now | M _K1 |. A corresponding reduction in the braking effect on the vehicle is shown in the longitudinal acceleration of the vehicle (negative in the overrun operating state, which can therefore also be referred to as a longitudinal deceleration), as is shown by way of example in the bottom diagram of FIG. 4. A gear is engaged on the transmission input shaft 2 which is higher than the gear engaged on the transmission input shaft 1. By means of the synchronization device of the transmission, this leads to a drop in the speed of the transmission input shaft 2 to the synchronous speed corresponding to the gear engaged.

Phase III

In order to prevent a further drop in the engine speed, the drag torque of the engine is reduced to | M _K1 | by appropriate intervention in the engine management reduced. The clutch 1 is in slip and a selected slip speed is adjusted via the clutch 1. After reaching the selected slip speed of clutch 1, clutch 2 is closed in a controlled manner. This triggers a further controlled opening of clutch 1, since the previously selected slip speed can only be kept constant if the sum of the moments M _K1 + M _K2 , which is transmitted from the two clutches to the engine, is constantly the same in this phase is the valid amount of engine drag torque.
MK1 + MK2 = | M _towing | The clutch 2 takes on more and more engine torque until the clutch 1 is fully opened.

Phase IV

The engine drag torque remains at the level from phase III. The clutch torque of clutch 2, M _K2 , is increased to the amount of the maximum engine _drag torque | M _drag | increases, which leads to an increase in the engine speed to the speed of the transmission input shaft 2.

The acceleration energy to be used

of the engine would result in a negative intermediate acceleration of the vehicle if not the negative engine torque by the amount

remains raised and the clutch torque of clutch 2 increases to | M _towing | remains. Because the negative engine torque by the amount

remains raised and the clutch torque of clutch 2 increases to | M _towing | remains, the drag torque acting on the transmission input shaft 2 and transformed into the transmission output shaft remains constant:

| M _towing | = M _K2 = | M _Mot | + | M _RotMot

This results in a correspondingly constant drag torque on the Transmission output shaft or - generally speaking - on the vehicle drive. The fully opened clutch 1 now allows the on the Take gearbox input shaft 1 out of gear virtually without torque.  

Phase V

The motor torque is brought back to the maximum drag torque. The clutch 2 is closed. The clutch 1 is closed. This leads to the speed n1 of the transmission input shaft 1 dropping to the level of the transmission input shaft 2. This gives additional torque

brought to the transmission output shaft. This Moment can be by means of an additional unit, for example by a suitable one Switching a crankshaft starter generator as a generator to be compensated.

Phase I (alternative)

It may be that before the start of the shift sequence - phase I - clutch 2 only is closed to such an extent that the transmitted drag torque is sufficient, the Maintain transmission input shaft 2 at engine speed. At the engine control nothing changes during the entire switching process.

Phase II (alternative)

The engagement of a higher one than that inserted on the transmission input shaft 1 Ganges inevitably leads to braking of the transmission input shaft 2.

This is an energy gain

connected, the extra moment

on the transmission output shaft. This moment can be compensated for by means of an additional unit, for example by suitably switching a crankshaft starter generator as a generator.
Or and:
The reduced drag torque | M _K1 | due to the opening of the clutch 1, which is transmitted to the transmission output shaft, can be increased to the original drag torque by means of an additional unit, for example by suitably switching a crankshaft starter generator as a generator.
Or and
It may be the case that clutch 2 is open at the start of the switching sequence. This means that the transmission input shaft 2 must be accelerated in phase 2. The energy required for this is drawn from the transmission output shaft, which leads to an increase in the drag torque at the drive. It can advantageously be provided that this increase in the drag torque reduces the clutch torque M _K1 below the maximum engine _drag torque | M _drag | compensated.

Phase III (alternative)

Alternatively, the engine torque can also be raised by means of an additional unit, for example a crankshaft starter generator.
Or and:
The engine torque is kept at the level of the maximum drag torque. The clutch torque of clutch 1, M _K1 , is increased to the amount of the maximum engine _drag torque | M _drag | increased to prevent a further drop in engine speed. Now a slip speed is adjusted via clutch 1, clutch 2 is closed in a controlled manner and clutch 1 is opened in a controlled manner.
Or and:
Alternatively, in phase III, the differential engine speed - transmission input shaft speed of the transmission input shaft 2 can be defined as the slip speed and can be regulated by clutch 2. The clutch 1 is then opened in a controlled manner and, as a result, the clutch 2 is closed in a controlled manner.

Phase IV (alternative)

Alternatively, the engine torque can also be raised by means of an additional unit, for example a crankshaft starter generator.
Or and:
The engine drag torque is brought back to the maximum drag torque. Since the motor and thus also the motor-side half of clutch 2 rotates at the speed of the input shaft 2 - slip speed, but the transmission-side half of clutch 2 rotates at the speed of the transmission input shaft 2, a further controlled closing of the clutch 2 increases its transmissible torque via the Engine _drag torque brought, M _K2 <| M _drag | to accelerate the engine speed to the speed of the transmission input shaft 2.

Phase V (alternative)

It can be provided that the clutch 1 is closed only to the extent that that its transmittable torque is sufficient, the transmission input shaft 2 on the Bring speed of the engine.

Result

The entire course of deceleration runs during the coupling process monotonously without intermediate deceleration or acceleration processes, since at the transmission output shaft is essentially a constant at all times permanent (phase I, IV, V) or monotonic (preferably strictly monotonic, e.g. linear) falling (phase II, III) drag torque acts.

Switching sequence PUSH-BACK

Assumption: it is in a coasting mode from a larger one, the Gearbox input shaft 1 assigned gear 1 to a smaller, the Gearbox input shaft 2 assigned to gear 2 switched.

With the push-return connection type, the motor delivers a drag torque to the Gearbox, which is referred to below as a negative torque.  

This negative torque is transmitted via the transmission input shaft 1. The Clutch 1 is connected to the transmission input shaft 1, clutch 2 to the Transmission input shaft 2. In the initial state, both clutches are complete closed and are therefore under pressure. Both As a result, transmission input shafts rotate at engine speed. On the Gearbox input shaft 1 is in gear and thus the frictional connection between the transmission input shaft 1 and the transmission output shaft manufactured.

A preferred switching sequence comprising five switching phases is explained below with reference to FIG. 5. The switching phases designated by the Arabic numerals 1 to 5 in FIG. 5 correspond to the following phases I to V. Possible variants and configurations of the switching phases are shown in dashed lines in FIG. 4 and are explained separately below as "alternatives" to the switching phase in question. To differentiate between the various curves and curve sections, these are identified by the identifiers N _Mo for engine speed, N _G1 for speed of gearbox input shaft 1, N _G2 for speed of gearbox input shaft 2, M _Mo for engine torque, M _K1 for clutch 1 torque and M _K2 for clutch torque 2 provided. An additional contribution to the changes in the speeds resulting from the negative longitudinal acceleration (deceleration) and representing the change in the vehicle speed is not taken into account in the partial diagram for the speeds. Furthermore, for the sake of simplicity, it was assumed that the engine torque remained constant over the engine speed (without active intervention in the engine control system). The switching process calculated from the beginning of switching phase 1 to the end of switching phase 5 could, for example, take about 0.5 to 1 seconds.

Phase I

In order to initiate the switching process, clutch 2 is opened completely.  

Phase II

The transferable clutch torque M _K1 is brought below the current amount of the engine torque.

M _K1 <| M _towing |

As a result, the engine speed falls below the speed of the synchronous speed of the transmission input shaft 1. The drag torque transmitted to the transmission input shaft 1 and thus to the transmission output shaft is now | M _K1 |. A resulting slight reduction in the engine braking effect on the vehicle is comparatively small and is not shown in the bottom diagram in FIG. 5 or is compensated for by a corresponding measure. A gear is engaged on the transmission input shaft 2 which is lower than the gear engaged on the transmission input shaft 1. By means of the synchronization device of the transmission, this leads to an acceleration of the speed of the transmission input shaft 2 to the synchronous speed corresponding to the gear engaged. This is the acceleration energy

needed, which is the moment of the transmission output shaft

would reduce.

In order to ensure a constant torque on the transmission output shaft, it can be provided that the additional drag torque due to the acceleration of the transmission input shaft 2 reduces the drag torque M _K1 caused by the opening of the clutch 1 below the maximum engine _drag torque | M _drag | compensated.

Phase III

In order to prevent a further drop in the engine speed, the drag torque of the engine is reduced to | M _K1 | by appropriate intervention in the engine management reduced. The clutch 1 is in slip and a selected slip speed is adjusted via the clutch 1. After reaching the selected slip speed of clutch 1, clutch 2 is closed in a controlled manner. This triggers a further controlled opening of the clutch 1, since the previously selected slip speed can only be kept constant if the sum of the moments M _K1 + M _K2 , which is transmitted from the two clutches to the engine, constant the amount of the drag torque of the Motors is.

M _K1 + M _K2 = | M _towing |

Clutch 2 takes on more and more engine torque until clutch 1 is fully open.

Phase IV

The engine drag torque remains at the level from phase III. Since the engine and thus also the engine side half of clutch 2 rotates at the speed of the input shaft 1 - slip speed, but the transmission side half of clutch 2 rotates at the speed of the input shaft 2, clutch 2 is closed in a controlled manner, the transmissible torque of which is equal to the amount of the drag torque of the Motor is, M _K2 = | M _towing |. The engine speed is hereby accelerated to the speed of the transmission input shaft 2.

The acceleration energy to be used

of the engine would result in a negative intermediate acceleration of the vehicle if not the negative engine torque by the amount

remains raised and the clutch torque of clutch 2 increases to | M _towing | remains. Because the negative engine torque by the amount

remains raised and the clutch torque of clutch 2 increases to | M _towing | remains, the drag torque acting on the transmission input shaft 2 and transformed to the transmission output shaft remains constant:

| M _towing | = M _K2 = | M _Mot | + | M _RotMot |

This results in a correspondingly constant drag torque on the Transmission output shaft or - generally speaking - on the vehicle drive. The fully opened clutch 1 now allows the on the Take gearbox input shaft 1 out of gear virtually without torque.

Phase V

The motor torque is brought to the maximum drag torque.

The clutch 2 is closed. The clutch 1 is closed. this leads to to decrease the speed n1 of the transmission input shaft 1 to the level of Transmission input shaft 2.

Phase I (alternative)

It may be that before the start of the shift sequence - phase I - clutch 2 only is closed to such an extent that the transmitted drag torque is sufficient, the Maintain transmission input shaft 2 at engine speed. At the engine control nothing changes during the entire switching process.

Phase II (alternative)

The reduced drag torque | M _K1 | due to the opening of the clutch 1, which is transmitted to the transmission output shaft, can be increased to the original drag torque by means of an additional unit, for example by suitably connecting a crankshaft starter generator as a generator.
Or and:
The negative intermediate acceleration process caused by the acceleration of the transmission input shaft 2 can be compensated for by means of an additional unit, for example by suitably connecting a crankshaft starter generator.

Phase III (alternative)

Alternatively, the engine torque can also be raised by means of an additional unit, for example a crankshaft starter generator.
Or and:
The engine torque is kept at the level of the maximum drag torque. The clutch torque of clutch 1, M _K1 , is increased to the amount of the maximum engine _drag torque | M _drag | increased to prevent a further drop in engine speed. Now a slip speed is adjusted, clutch 2 is closed in a controlled manner and clutch 1 is opened in a controlled manner.
Or and:
Alternatively, in phase III, the differential speed of engine speed-transmission input shaft speed of transmission input shaft 2 can be defined as the slip speed and can be regulated by clutch 2. The clutch 1 is then opened in a controlled manner and the clutch 2 is closed in a controlled manner in succession.

Phase IV (alternative)

Alternatively, the engine torque can also be raised by means of an additional unit, for example a crankshaft starter generator.
Or and:
The engine drag torque is brought back to maximum drag torque. Since the engine and thus also the engine-side half of clutch 2 rotates at gearbox input shaft 2 - slip speed, but the gearbox-side half of clutch 2 rotates at gearbox input shaft 2 speed, further controlled engagement of clutch 2 brings its transmissible torque to the engine drag torque , M _K2 <| M _towing | to accelerate the engine speed to the speed of the transmission input shaft 2. Shortly before the synchronous speed is reached, the clutch torque of clutch 2 changes to MK2 | M _Schlepp | reduced.

Phase V (alternative)

The clutch 1 is closed. This leads to an increase in the speed n1 of the transmission input shaft 1 to the level of the transmission input shaft 2. In order to accelerate the transmission input shaft 1, the acceleration energy becomes

needed. To avoid a negative intermediate acceleration of the vehicle, the negative engine torque by the amount

be raised so that the drag torque on the drive of the vehicle remains constant.
Or and:
It can be provided that the clutch 1 can only be closed to such an extent that its transmissible torque is sufficient to bring the transmission input shaft 2 to the speed of the engine.

Result

The entire course of deceleration runs during the coupling process monotonously without intermediate deceleration or acceleration processes, since at the transmission output shaft is essentially a constant at all times permanent (phases I, II, IV, V) or monotonic (preferably strictly monotonic, z. B. linear) increasing (phase III) drag torque.  

Fig. 6 shows a further example of a drive train 10 of a motor vehicle. Only the changes compared to the drive train according to FIG. 1 are explained. Instead of a dual clutch 24 with two wet-running disk clutch assemblies 26 and 28 is a double clutch is in the example of Fig. 6 24 calculations with two dry-running Kupplungsanord 26 and 28 of the friction disk is provided. The two friction-disk clutch arrangements can be actuated, for example, by means of hydraulic slave cylinders integrated in the double clutch in a hydraulic way, which is assumed in FIG. 6. Corresponding implementation options can be found, for example, in DE 35 26 630 A1. However, it is also possible to use dry-running double clutches with a completely different design, for example reference is made to EP 0 931 951 A1.

Below 7, further exemplary switching operations are now described with reference to FIG. To 9 (15 cf. Also Fig. 10 and Fig.) Explains the embodiments of an operating method according to the invention for a drive train, such as the drive train of FIG. 1 or FIG. 6 , realize. The switching sequences can be realized, for example, by means of the control unit 36 by correspondingly actuating the drive unit 12 , the clutch arrangements 26 and 28 and, if appropriate, the auxiliary unit 50 , if appropriate as a function of parameters specified by the unit 38 . The switching sequences are preferably carried out fully automatically by the control unit 36 .

In the following explanations, the focus of which is on the difference compared to the switching sequences according to FIGS. 2 to 5 (knowledge and understanding of these switching sequences is assumed to this extent), in turn, on transmission input shafts 1 and 2, clutches 1 and 2 and gears 1 and 2 Referenced. The transmission input shaft 1 can correspond to the shaft 20 and the transmission input shaft 2 to the shaft 22 , or vice versa. Accordingly, the coupling 1 of the coupling arrangement 26 and the coupling 2 of the coupling arrangement 28 can speak ent, or vice versa. Gear 1 is a gear assigned to the transmission input shaft 1 (the output gear) and gear 2 is a gear assigned to the gear input shaft 2 (the target gear).

FIG. 7 shows an example of a shift sequence according to the invention, in which the friction work occurring in the overlap shift phase for the clutch arrangements is reduced, but nevertheless a "soft" acceleration transition is ensured. The switching sequence according to the invention in accordance with the exemplary embodiment dealt with here is characterized by a comparatively long (for example 700 ms) transition phase in which the longitudinal acceleration of the vehicle drops strictly monotonously, in the present case linearly and continuously. This transition phase is formed in the execution example of the sub-phases A, B and C, of which the sub-phase B is the overlap circuit phase in which the two clutch arrangements are actuated in opposite directions to redistribute the drive torque from one to the other transmission input shaft. As in the exemplary embodiments from FIGS . 2 to 6, it is assumed in this and in the following exemplary embodiments that the output gear is gear 1 (to which the transmission input shaft 1 and the clutch arrangement 1 are assigned) and that the target gear is gear 2 (To which the transmission input shaft 2 and the clutch assembly 2 is assigned).

The overlap circuit phase B can be a length, for example from about 100 to 150 ms. The overlap circuit phase B is preceded by phase A, referred to as the "gradient phase" has a length of 400 to 500 ms. The overlap circuit phase B follows what is also referred to as the "gradient phase" Phase C after, which has a length of 100 to 150 ms, for example.  

In the gradient phase A falls a phase II (in the figure by the corresponding Arabic numeral 2 in a circle), in which the target gear 2 is actuated in the sense of an engagement, so that the transmission input shaft 2 under the action of the synchronizing device of the transmission is brought to a speed corresponding to the instantaneous speed of the transmission output shaft, so that at the end of this partial phase II, which corresponds to phase II according to FIG. 2, the gear is engaged.

A reduction in the rebars occurring on the clutch arrangements beit results primarily from the shortening of the overlap scarf phase B compared to the transition that determines driving comfort phase in which the longitudinal acceleration changes. In the overlap The clutch arrangements become strong burdened by slip.

According to the exemplary embodiment, in phase A, by intervening in the engine management, the torque given off by the engine is reduced in a strictly monotonous manner (in this case, linearly), to the moment value M ₁ at the end of phase A. Disengaged actuated so that the torque from the clutch arrangement 1 is essentially equal to the engine torque. This can be achieved, for example, by a so-called micro-slip control, in which a so-called micro-slip (eg 10 to 50 rpm) is regulated by means of the clutch arrangement. Thus, at the end of phase A, the torque that can be transmitted (and actually transmitted) by the clutch arrangement _{1 has} dropped to the value M ₁ . In principle, however, it is also possible to decouple the actuation of the clutch arrangement from the change in the engine torque. It is crucial that in phase A of the clutch assembly 1 a dropping according to the desired change in the longitudinal acceleration drive torque is transmitted to the transmission input shaft 1, and it does not matter in itself whether this is due to a corresponding change in the engine torque and / or a corresponding change in the engagement state the clutch nan order 1 is reached. For example, one could reduce the engine torque in the manner shown in FIG. 7 in the second uppermost diagram and leave the clutch arrangement 1 fully engaged over phase A and only actuate in the sense of disengagement at the end of phase A, so that this is from this clutch arrangement transmissible torque approximates the engine torque at the end of phase A. The Darge shown in Fig. 7 actuation of the clutch assembly 1 appears particularly advantageous because it opens up the possibility of a simple micro-slip control.

The fact that at the beginning of the overlap shift phase B, the clutch torque is already reduced to the value M ₁ , there is a further reduction in the total amount of friction work occurring in phase B for clutch arrangement 1 due to clutch slip, since the frictional power occurring at the clutch arrangement is proportional to the transmission Torque (friction power = transmission torque × slip speed). At the beginning of the overlap shift phase B, the torque acting on the clutch arrangement 1 has already been reduced, which results in a corresponding reduction in the friction work per unit of time over the phase B.

In the course of the overlap shift phase B, the engine torque M _{Mo is} then increased again, to a value M ₂ which is above the torque M _FW (driver's desired torque) prevailing before the shift sequence begins. This ensures that at the end of phase B the drive torque M _GA occurring at the transmission output is even greater than the drive torque corresponding to the driver's desired torque, taking into account the torque transformation resulting from the change in the transmission ratio. The change in the longitudinal acceleration is therefore not yet complete, but can then be continued via the gradient phase C by the clutch arrangement 2 being actuated again in the sense of a slight disengagement. The torque that can be transmitted by the clutch arrangement 2 (and thus the torque that is actually transmitted by this clutch arrangement) drops from the value M ₂ at the beginning of phase C to the driver's desired torque M _FW at the end of phase C, which completes a change in the longitudinal acceleration that in terms of the difference between the longitudinal acceleration before and after the shift sequence corresponds to a change in the longitudinal acceleration resulting from the rearrangement of a constant drive torque from the transmission input shaft 1 to the transmission input shaft 2 due to the change in the gear ratio. The vehicle occupants experience inertia forces as would occur if the overlap switching phase were extended to the entire transition phase A + B + C. The driving comfort is thus achieved as in a relatively long overlap shift phase, without having to put up with a correspondingly large friction load due to clutch slip for the clutch arrangements. It should be noted that for the clutch arrangement 2 at the end of phase B a somewhat increased friction work occurs per unit of time, since the clutch torque is raised to the value M ₂ via the driver's desired torque. However, this effect is subordinate to the shortening of the overlap circuit phase B compared to the transition phase. Overall, a significant reduction in friction work can be achieved by reducing the length of the overlap shift phase for both clutch arrangements.

Regarding the second uppermost diagram in FIG. 7, it should also be explained that in phase C the engine torque is reduced in order to “use up” the clutch slip on the clutch arrangement 2, that is to say to pull the engine speed down to the speed of the transmission input shaft 2. Since the torque transmitted in phase C is limited upwards by the transferable torque of the clutch arrangement 2 and stored energy is retrieved in the engine's flywheel when the engine torque is deflected, with the engine being braked accordingly, it depends on the exact course of the engine torque reduction not in phase C. However, it is advisable to "use up" the clutch slip as quickly as possible in order to keep the friction work still occurring in phase C for the clutch arrangement 2 as small as possible. Therefore, according to the exemplary embodiment, the motor drive is switched off completely, so that the negative motor friction torque (motor drag torque) acts and, accordingly, the clutch slip is temporarily used up.

Shortly before adjustment of the engine speed to the speed of the transmission input shaft 2, the engine torque is increased again in such a way that, after the slip has been used up, the engine torque is equal to the target engine torque M _FW . The clutch arrangement 2 can then be fully engaged since the torque that can be called up by the engine now has a limiting effect. Apart from a contribution to the braking of the transmission input shaft 1 when the clutch arrangement 1 is engaged, it is in principle irrelevant when the clutch arrangement 1 is engaged again (if this is desired at all).

With regard to the representation in FIG. 7, it is also pointed out that portions of the curves shown in dashed lines are purely exemplary and that the curves could in principle run in any desired manner in these time ranges. Regarding the third uppermost diagram, it should also be pointed out that the actual transmission output torque MGA is not shown, but rather the transmission output torque transformed on the transmission side according to the translation of the gear train assigned to the clutch arrangement 2. Had the actual transmission output torque been drawn in, the torque transmitted by the clutch arrangement 2 at the end of phase B could not be the same as the transmission output torque, unless the transmission ratio 1: 1 applies in gear 2. In the case of a gear ratio not equal to 1: 1, the same representational transformation must be assumed for the three output phases A, B and C, i.e. also in phases A and B, in which the clutch arrangement 1 and the transmission gear 1 are effective.

As far as the friction work for the clutch assemblies possible to reduce, it is recommended that those phases or temporal To extend sections of the switching sequence as far as possible in which no clutch slip or at most minimal slip, for example Micro slip occurs. For example, phase A could be special choose long. One could then do without phase C.

If you want to do without phase C, you could raise the clutch torque for clutch arrangement 2 to setpoint M _FW in phase B. In this case, the engine torque in phase B will be increased accordingly less, for example to the value M _FW at the end of phase B.

A switching sequence according to the invention, for example as shown in FIG. 7, can be implemented as follows, for example. Phase A begins with the triggering of the switching request (if necessary, automated via switching characteristics or via a manually operated switch). After the shift request is triggered, a desired acceleration gradient is calculated, with which the target acceleration level is to be reached from the initial acceleration level. The start and end times of the individual sub-phases (phases A, B and C) can then be determined using this gradient. These times then determine the necessary torque reduction (in the example, engine torque reduction) in phase A starting from the driver's desired torque M _FW to the value M ₁ . This reduction is achieved in the exemplary embodiment by a corresponding intervention in the engine management.

The amount of torque reduction is dependent on the gear ratio jump between the starting and target gears, and the proportion of this torque reduction that is attributable to phase A is dependent on the length of time t ₁ of phase A. If a linear torque reduction is taken as a basis, then the torque value M _{1 is} calculated at the end of phase A.

M ₁ = M _FW × (1 - (1 - i _Z / i _A ) × t ₁ / t _g )

where i _A , i _Z and t _{g denote} the gear ratio in the initial cooking (i _A ), in the target gear (i _Z ) and the total duration 19 of the transition phase A + B + C (x = multiplication operator). This formula can be easily derived on the basis of the straight line equation and the assumption that the vehicle acceleration corresponds to the product of the transmission input torque and transmission ratio.

After in phase A the clutch arrangement of the output gear in Is engaged and the clutch of the target gear is open or is opened, Phase B is characterized by the torque transfer from the clutch arrangement 1 on the clutch assembly 2. According to the out In this example, an engine speed is set in this phase is above the speeds of both transmission input shafts, so that one clutch assembly is controlled and the other based of clutch slip can be operated in a controlled manner. For example the clutch arrangement 1 is opened in a controlled manner and the clutch arrangement 2 regulated closed.

In the exemplary embodiment, the target value M _{2 of} the clutch torque of the clutch arrangement 2 is above the driver's desired torque M _FW . Assuming a linear course, the value M _{2 is} calculated

M ₂ = M _FW × (1 - (1 - i _Z / i _A ) × t ₂ / t _g ) × i _A / i _Z

t ₂ indicates the duration of phase A and phase B together, i.e. determines the end of phase B.

Phase C is determined in the exemplary embodiment by the approximation of the engine speed approximately from the level of the transmission input shaft speed 1 to the level of the transmission input shaft speed 2. As mentioned, the engine torque can be induced to a maximum of the engine friction torque. The clutch torque is reduced from the moment M ₂ to the moment that corresponds to the driver's desired torque. After the same of the speeds of the engine and the transmission input shaft 2, the clutch assembly 2 can then be completely closed. The clutch arrangement 1 can be closed again immediately after disengaging the gear 1 or at a later point in time in order to match the speed of the transmission input shaft 1 to the speed of the transmission input shaft 2. The uppermost diagram in FIG. 7 assumes that clutch arrangement 1 is closed again immediately after gear 1 is disengaged. In the third uppermost diagram, two different options for closing the clutch arrangement 1 are shown in dashed lines. You can also keep the clutch assembly 1 open, depending on the circuit concept implemented.

Concerning the speed curves in FIG. 7, it is also pointed out that, in deviation from the representations according to FIGS. 2 to 5, an increase in the speeds corresponding to the instantaneous vehicle acceleration is taken into account.

Fig. 8 shows an embodiment of a switching sequence according to the invention for the case of a downshift under thrust conditions. It is again assumed that the starting gear (the higher gear) is addressed as "gear 1" and that the target gear (the lower gear) is addressed as "gear 2". In the embodiment, the "transition phase" is formed by phases B and C, of which phase B is the overlap circuit phase. Starting from a state in which a drag torque M _{S is} applied by the engine, for example the friction torque according to FIG. 7, the drag torque of the engine is brought to a drag torque value M in phase B by appropriate intervention in the engine management (by corresponding “accelerating”) ₁ reduced, linear in the example. The clutch arrangement 2 is engaged in phase B to such an extent that its transmissible torque corresponds approximately to the drag torque M ₁ . Thus acts at the end of phase B on the transmission output, a drag torque that is greater than it would be due to a transmission input-side drag torque M _S on the transmission input shaft 2 due to the effective gear ratio in gear 2. Accordingly, the vehicle deceleration (negative longitudinal acceleration) has not yet reached its end value at the end of phase B, but is only linearly brought to the end value in phase C by corresponding actuation of the clutch arrangement 2 (increased in amount). This results in a corresponding enlargement of the transition phase compared to the overlap switching phase, for example to a value t _g = 500 to 700 ms (for example compared to a value t ₁ of 300 to 500 ms for the overlap switching phase B.

In phase C there is an appropriate intervention in the engine management first the engine drag torque is relatively further reduced to the Align engine speed with the speed of transmission input shaft 2 and thus use up the slip of the clutch assembly 2. After that the engine drag torque is returned to the initial value M5 leads. The clutch arrangement 2 is gradually closed in such a way that that their transmissible moment of the desired longitudinal acceleration in corresponds to phase C.

One could also include, for example, a phase A preceding phase B (in which sub-phase II falls, in which target gear 2 is engaged with corresponding synchronization of the rotational speeds) in the transition phase, for example by using an additional unit (for example, crankshaft starter generator 50 according to FIG . 1 or 6 or the braking system of the vehicle), a corresponding negative torque, that is a corresponding extra drag torque is generated.

Fig. 9 shows an example of a switching sequence according to the invention in the case of a train downshift, that is, for a downshift under train operating conditions. It is again assumed that the starting gear (the higher gear) is referred to as "gear 1" and the target gear (the lower gear) as "gear 2". The representation of the diagrams of FIG. 9 corresponds to the representation of the diagrams of FIG. 3. The change in the rotational speeds due to the effective vehicle acceleration is therefore not taken into account, and phases I to V of FIG. 3 are identified in the shift sequence, whereby as in FIG. 3, the Arabic number corresponding to the Roman switching phase number is entered in a respective circle in FIG. 9.

Phase III can be identified as the overlap circuit phase or phase B in the sense of the preceding examples according to FIGS . 7 and 8. In addition to the overlapping circuit phase III, the transition phase also includes the preceding phase II (= phase A) and the subsequent phase IV (= phase C).

In order to achieve an acceleration gradient in phase A, the clutch torque M _K1 is in phase A after the production of clutch slip by lowering the clutch torque of the clutch arrangement 1 to the initial value of the engine torque M _FW and raising the engine torque M _Mo above this value linearly increased to the value M _{1 in} accordance with the desired gradient, with a simultaneous further increase in the engine torque M _M0 , so that the engine torque is always above the clutch torque. For example, the difference between these moments is set such that the engine speed runs up to a predetermined speed level above the new synchronous speed resulting from the engagement of gear 2.

It should be noted that this sequence is only possible if the vehicle has not previously been driven with maximum engine torque or if, in the case of driving with maximum engine torque, an additional torque can be supplied by an additional unit (such as the crankshaft starter generator). Before the switching sequence is carried out, it must therefore be checked whether this switching sequence is even possible. If this is not the case or, for example, a "sport mode" is selected after a faster and less comfortable change in the longitudinal acceleration is desired, the shift sequence of FIG. 3 can be used, for example, in order to reduce the frictional load on the clutch arrangement in the overlap shift phase, this then correspondingly in terms of time can be shortened. There are also other variations or combinations of the switching sequence according to FIG. 9 and the switching sequence according to FIG. 3. For example, when the maximum engine torque is present, the change in longitudinal acceleration can be distributed to phases 3 and 4, which means that little or no reduction in friction work is achieved, but greater comfort is also achieved in the “sport mode” mentioned.

In phase III, i.e. in the overlap circuit phase B, the engine torque is reduced to the value M ₂ , which is below the target value MFw at the end of the transition phase, so that the final value of the longitudinal acceleration has not yet been reached. The clutch arrangement 2 is controlled or regulated in phase III in such a way that its transmissible torque also assumes the value M ₂ at the end of phase III. If the clutch arrangement 1 is opened in a controlled manner and the clutch arrangement 2 is closed in a controlled manner, the transferable torque of the clutch arrangement 2 automatically increases to the value M ₂ at the end of phase III.

In phase IV (phase C), the clutch torque of the clutch arrangement 2 is then ramped up to a value corresponding to the original engine torque (that is, corresponding to the target engine torque M _FW ). The engine torque is below the clutch torque in phase IV and is only controlled to the original torque M _FW at the end of phase IV so that the engine speed adapts to the speed of the transmission input shaft 2. Thereafter, the engine torque remains in phase V at the value M _FW , and the clutch assembly 2 can be fully engaged.

Another example of a train downshift according to the invention is shown in FIG. 10. The type of representation corresponds to the examples of FIGS. 7 and 8, the change in the speeds due to the prevailing vehicle acceleration is therefore taken into account.

According to the example in FIG. 10, at the beginning of the gradient phase A, the engine torque is rapidly increased from the driver's desired torque M _FW to the maximum engine torque M _{max in} order to bring the engine speed to the target speed as quickly as possible. For this purpose, a corresponding slip on the clutch arrangement 1 is accepted. The clutch arrangement 1 is gradually ramped up from an engagement state in which the transferable torque M _FW is to a transferable torque corresponding to the torque value M ₂ at the end of phase A, with a corresponding change in the longitudinal acceleration. In a partial phase of phase A which can be identified as "phase II" in the sense of the previously discussed exemplary embodiments, the target gear 2 is engaged so that the speed of the gearbox drives input shaft 2 and at the end of this partial phase II gear 2 is engaged. The overlap shift phase B essentially corresponds to the overlap shift phase B of the example in FIG. 9. The engine torque is thus reduced to a value below the driver's desired torque M _FW , simultaneously with the opposite actuation of the two clutch arrangements. At the end of phase B, the drive torque on the transmission output shaft and, accordingly, the longitudinal acceleration of the vehicle have not yet reached their final values, so that in gradient phase B, by increasing the engine torque to the value M _FW with appropriate actuation of the clutch arrangement 2, the torque on the transmission output shaft and thus the Longitudinal acceleration are brought up to the values which correspond to the gear ratio in target gear 2 on the basis of the driver request torque M _FW applied to the transmission input.

Regarding the provision of a transition phase that is longer than the pure overlap circuit phase, no separate example needs to be given for a push-up shift, it is sufficient to refer to the example according to FIG. 4. By appropriate actuation of the clutch arrangement 1 in the disengaging sense in phase II such that its torque transmission capability falls below the drag torque of the moment and, if necessary, further reduced in the course of phase II in a desired manner, the drag torque applied to the transmission input shaft I can and accordingly the drag torque transformed to the transmission output can be reduced, so that the braking effect on the vehicle already decreases in phase II and the vehicle deceleration (negative acceleration) is reduced accordingly, if necessary not only approximately, but even exactly linearly. Another possibility is to reduce the drag torque of the engine itself by appropriate intervention in the engine management. If an additional unit, such as a crankshaft starter generator, is available, one could increase the drag torque effective at the transmission input compared to the output value in the course of the overlapping circuit in phase III and then return it to the initial value in phase IV. For this purpose, one could also use the vehicle brake, which can be regarded as an "additional unit". The transition phase comprising the overlap phase III can thus be easily extended, for example, to phase II and phase IV.

Through the extension described above using several examples the time interval in which the vehicle changes the longitudinal acceleration tion or longitudinal deceleration, which, if desired, with regard to the Difference between the initial value before the end of the shaft and the final value after the switching sequence exactly or approximately resulting from the change the gear ratio change resulting in the gear ratio equivalent, two goals that are contrary to each other can be achieved simultaneously on the one hand, the provision of a short or as possible short overlap circuit phase to reduce the on the Kupp Development arrangements occur friction work or the heat input to the Coupling arrangements and on the other hand a high driving comfort with only gradually changing longitudinal acceleration or deceleration and accordingly only gradually changing inertial forces acting on the vehicle occupants act. The proposed invention in this regard can both with wet-running multi-plate clutch arrangements and with dry-running clutch arrangements, for example the friction disks design, find application, the invention proposal for the last mentioned application, i.e. for dry running clutch arrangements, is of particular importance since the clutch runs dry orders the friction load a much more important one The point of view is that the resilience due to friction is usually lower than with wet-running multi-plate clutch arrangements.

In the following, further exemplary switching sequences are explained with reference to FIGS. 11 to 14, which implement embodiment variants of an operating method according to the invention for a drive train, for example the drive train of FIG. 1 or FIG. 6. The switching processes can be implemented, for example, by means of the control unit 36 by correspondingly controlling the drive unit 12 , the clutch arrangements 26 and 28 and - where appropriate - the auxiliary unit 50 and in particular also the vehicle brakes, if necessary as a function of parameters specified by the unit 38 , Before switching operations are carried out fully automatically by the control unit 36 .

In the following explanations, the focus of which is on the difference compared to the shift sequences of the previous figures (knowledge and understanding of these shift sequences is presupposed insofar), again reference is made to transmission input shafts 1 and 2, clutches 1 and 2 and gears 1 and 2 taken. The transmission input shaft 1 can correspond to the shaft 20 and the transmission input shaft 2 can correspond to the shaft 22 or vice versa. Accordingly, the clutch 1 may correspond to the clutch arrangement 26 and the clutch 2 to the clutch arrangement 28 , or vice versa. Gear 1 is a gear assigned to the transmission input shaft 1 (the output gear) and gear 2 is a gear assigned to the gear input shaft 2 (the target gear).

The switching sequences of FIG. 11 to 14 relate to push-back circuits. In this context, reference is once again made to the switching sequences according to FIGS. 5 and 8, which likewise each relate to a push-down shift. Referring to FIG. 5 and FIG. 8, the engine speed is below the speed of the current (the off gear, gear associated with) transmission input shaft accommodated in Phase II or Phase B. A motor-assisted synchronization of the target gear is therefore not possible, so that the synchronization of the target gear must be accomplished solely by the affected synchronous units of the transmission with a corresponding load on the affected synchronous units or generally the synchronous device or synchronous devices of the transmission.

Would you like the synchronizer or synchronizers relieve, one might think of having larger switching times in place to take. The switching times depend on the power, which can or must apply the synchronization unit. The slower that respective transmission input shaft is accelerated the less  requested the synchronization device concerned. A clear extension The switching time will usually not be considered. at Low temperatures are the mentioned switching processes for the thrust Downshifting may be problematic in that in In extreme cases a downshift in the overrun could not be possible. Also At operating temperatures, a quick downshift can be problematic be, specifically a downshift from the second to the first Gear, as this is where the gear spread is usually greatest.

In contrast, the switching sequence shown as an example in FIG. 11 offers the advantage that a thrust downshift without interruption in traction is made possible while relieving the load on the synchronizing devices. An essential aspect is that a braking or drag torque of the drive unit is substituted by a replacement braking torque provided by a brake arrangement, in particular the normal vehicle brakes, in order to prevent an undesired positive acceleration process, while active synchronization by means of the engine (in general the drive unit) is carried out.

In phase 1, clutch 1 is closed and transmits the maximum Drag or braking torque of the drive unit (the motor). The dome lung 2 can be open or closed at the beginning of the switching sequence. in the In the case of an open clutch, clutch 2 becomes slightly in the direction of engagement actuated to drive torque from the engine to the transmission input shaft 1 to be able to transfer. In the case of a previously closed clutch the clutch 1 is opened accordingly.

In phase II, the clutch 1 assigned to the output gear is essentially opened completely and accordingly the clutch torque of this clutch is reduced approximately to zero. Without additional measures, the vehicle, which is in a coasting state, would be accelerated, or at least the previous vehicle deceleration (negative longitudinal acceleration) would drop significantly. In order to prevent this undesirable positive acceleration process or drop in vehicle deceleration, a braking torque M _{BR is brought} to the wheels of the motor vehicle, or at least to the drive wheels of the motor vehicle, which corresponds to the previous drag or braking torque of the motor with the help of the vehicle brake. The engine torque is now raised to a positive value above the clutch torque of clutch 2 so that the engine revs up to the synchronous speed of the target gear (gear 2). Here, the transmission input shaft 2 is taken along via the clutch 2, since the clutch 2 transmits torque to its transmission input shaft. When the transmission input shaft 2 reaches its new synchronous speed, the clutch 2 is opened again in order to be able to engage the new gear (target gear, gear 2) essentially without stressing the synchronizing device of the transmission. It is entirely possible to actuate the synchronizing device of the new gear in the engagement direction as soon as the engine is turned up.

After reaching the synchronous speed, the engine torque in phase III is gradually reduced back to the original drag or braking torque, which is accompanied by a reduction in the engine speed. So that the engine speed does not drop too quickly, it is advisable to lower the engine drag torque approximately as quickly as the clutch 2 is closed and thus transmits torque and thus intercept the falling engine speed. In this context, it is primarily thought that the clutch 2 is closed in a controlled manner until the engine speed again corresponds to the new synchronous speed. The clutch 2 then transmits the entire engine drag torque. Preferably, the control (one could also provide regulation) with decreasing slip speed is always more sensitive in order to ensure an asymptotic transition of the engine speed to the transmission input shaft speed. The braking torque applied by the vehicle brakes should be controlled or regulated as precisely as possible in the manner in which the engine drag torque is built up by engaging the clutch 2 on the transmission output shaft. It is therefore ideally always a thrust torque on the output which corresponds in phase III to a continuous (possibly linear) shift of the thrust torque provided by the drive unit before the shifting process begins from the transmission input shaft 1 to the transmission input shaft 2. In phase III, to a certain extent, an “overlap circuit” is carried out between the vehicle brakes on the one hand and the clutch 2 assigned to the target gear or the drive unit on the other hand, so that, for example, the longitudinal acceleration shown in FIG. 11 is achieved.

In phase IV, clutch 2 is then closed completely. The target gear can be designed and the clutch 1 closed, which leads to an increase in the speed N _{G1 of} the transmission input shaft 1 to the level of the transmission input shaft 2. Alternatively, the clutch 1 can also remain open.

Since the clutch torque of the clutch 2 assigned to the target gear is greater than zero in phase 11 , active synchronization of the transmission input shaft 2 is possible, so that the relevant synchronization device is relieved. If clutch 2 remained fully open in phase II, the synchronizing device would have to bring about full synchronization of the transmission input shaft 2.

The relief effect for the synchronizer or synchronizer Siereinrichtung the transmission is not from the substitution of the towing moments dependent on a braking torque. You can push back Accordingly, carry out the shift without brake support ren to the synchronizer or synchronizers active to relieve. Without brake support, however, a positive intermediate acceleration or at least a temporary reduction in  Vehicle deceleration can be accepted, which is for reasons of comfort may not be desired.

Fig. 12 shows an embodiment variant of the switching sequence of FIG. 13. Since at the beginning of phase III in FIG. 11 there is the same speed between the drive unit and the gear input shaft 1 assigned to the target gear, the clutch 2 can in principle be engaged as far as desired in this phase without the drive train jerking. For example, the clutch 2 can be engaged at least to such an extent that the torque that can be transmitted by the clutch 2 corresponds to the engine braking or drag torque that prevailed at the start of the shifting sequence (for example the maximum possible engine drag torque).

Against this background, the clutch 2 in Phase I at zero in Fig. 12 beginning controlled until the end of phase III, for example by means of a entspre sponding pressure ramp, closed, so that at the end of phase III, the transferable clutch torque corresponding to the engine drag torque mentioned. In phase III, the engine torque and the braking torque are reduced in a manner coordinated with one another in the manner of an “overlap circuit”, for example in order to achieve the change in the longitudinal acceleration shown below in FIG. 12. On the output or on the vehicle wheels, overall, a braking torque continuously changing in phase III acts, which is the sum of the braking torque M _BR applied by the vehicle brakes and the momentary engine torque M _MO transmitted via the transmission, more precisely the target gear 2 and the clutch 2 is. The decisive factor is not the torque M _MO introduced into the transmission, but rather the torque resulting from the transmission, taking into account the transmission ratio, due to this torque M _MO .

Fig. 13 shows a further embodiment of the shifting sequence. In this shift sequence, clutch 2 assigned to the target gear is already completely closed in phase III. Otherwise, the switching sequence corresponds to the switching sequence of FIG. 12.

The switching sequence of FIG. 14 shows two variants of the shift sequence of Fig. 13. In a first variant (solid braking torque curve and solid longitudinal acceleration curve) is increased, the brake torque in phase II linear, carry with a corresponding increase in the loading of the negative longitudinal acceleration , In phase III, the braking torque is then changed to the same extent (ie the same rate of change) as the engine torque (the engine torque from a slightly positive torque to a negative drag or braking torque), so that the longitudinal acceleration of the vehicle remains essentially constant in phase III.

In contrast, in the second variant (dashed braking torque curve and dashed longitudinal acceleration curve) the engine torque is increased less strongly in phase II, and in phase III the rate of change of the braking torque MBR is smaller than the rate of change of the engine torque M _MO , so that over phases II and III a strictly monotonous, in the present case linear increase in the braking effect on the vehicle, that is to say a linear increase in the amount of negative longitudinal acceleration is achieved.

The two variants in FIG. 14 indicate two variants of the shift sequence for the push-down shift, in which a spontaneous delay is achieved to a certain extent after a downshift command in overrun mode, namely from the beginning of phase II. This may be advantageous with regard to the psychology of a typical driver, since he expects the motor vehicle to react spontaneously to shift commands issued by him in a manual shift mode.

It should also be pointed out the following: For reasons of comfort it would be Certainly ideal if there is always a push or pull force when shifting interruption is avoided. However, within the scope of the invention  definitely provide that in certain situations a thrust is under break or traction interruption is accepted to the Friction work on the clutches and / or on the synchronizing devices to reduce or avoid as much as possible. It will be in this Relation in particular to certain situations in pushing operation thought. Is the (in overrun) negative longitudinal acceleration of the Vehicle is small, the driver or the vehicle occupants caused by an interruption in thrust, comparatively slight change in longitudinal acceleration is accepted and not as a comm forfeited be felt. This applies to both a push-return Circuit as well as for a push-up circuit. With a thrust high The circuit also adds to the longitudinal acceleration of the vehicle the circuit will be larger due to a lower braking effect of the motor. An interim slight free acceleration or Rolling of the vehicle due to an interruption in thrust is likely without more will be accepted.

The above applies in a corresponding manner to train operating states. If the (positive) longitudinal acceleration of the vehicle is low, then by the driver or the vehicle occupants due to an interruption in tractive power induced, comparatively minor changes in the longitudinal Acceleration accepted and not perceived as a loss of comfort.

Both for train operating conditions and pushing operating conditions it is specifically proposed that, based on the amount of instantaneous longitudinal acceleration of the vehicle is decided whether with Interruption of traction or pushing force or without traction or pushing force refraction should be switched. The corresponding circuit can auto matatised by a corresponding functionality of a control device be performed.  

Insofar as an interruption in the thrust force per se occurs, the thrust torque of the drive unit can be substituted by a braking torque of a brake device, in particular the vehicle brakes, in accordance with the proposals on which FIGS . 11 to 13 are based. In the load-free state of the drive train brought about after disengaging the clutch gear associated with the output gear, active synchronization can advantageously be carried out by actively adjusting the engine speed to the synchronous speed of the target gear. By dispensing with the "overlap circuit" between the two clutch arrangements, the friction work for both clutch arrangements or their friction linings is minimized.

Above all, the reduction of friction work on the clutch assemblies also for dry running clutch arrangements of a multiple clutch lungseinrichtung, in particular double clutch, of interest to the To protect friction linings and to extend the life of the friction linings. According to a conventional approach, the advantage of the double clutch gear, namely the traction or shear interruption-free scarf always used regardless of the driving situation by the known "overlap circuit" is carried out at the same time tig one clutch assembly closed and the other clutch arrangement is opened, respectively on both transmission input shafts a gear is engaged, namely on the one transmission input shaft Output gear and on the other transmission input shaft the target gear. The one during the torque transmission from one to the other Clutch arrangement resulting friction energy leads to lining wear and Heat input into the coupling arrangements, possibly the pressure plates. It was recognized that it is not necessary to switch this principle process regardless of the driving situation. If you do without the traction-uninterrupted or push-uninterrupted for certain switching situations, this results in a corresponding discharge tion of the friction linings.  

With a thrust-downshift indicating switching sequence of FIG. 15 is yet another example for the embodiments of Figs. 7 to 10 underlying theme, namely, the reduction of the friction work by reducing the length of an overlap shift phase (such provided with thrust Downshifts is still provided), with a longer transition phase compared to the overlap phase. For the exemplary embodiment in FIG. 15, the premises and the nomenclature apply, as stated above with reference to FIGS. 7 to 9).

According to Fig. 15 is in phase II which consists of a downshift under Schubbe an overlap circuit conditions in conflict with each change resulting (magnification) of the motor caused, acting on the driven vehicle wheels braking torque and thus the amount-related increase in the negative longitudinal vehicle acceleration by entspre sponding actuation of the vehicle brakes in a sense already anticipated. According to the engine torque shown in dashed lines, a negative torque contribution from a crankshaft starter or the like could also be set. In general, a corresponding negative torque can be achieved by corresponding actuation / control of the torque generation arrangement, in particular by corresponding actuation of the vehicle brakes and / or by appropriate actuation of the crankshaft starter generator.

According to the switching sequence of FIG. 15, the braking torque M _Br is linearly increased during phase II, with a corresponding change in the Fahrzeuglängsbe acceleration. In phase III, the overlap shift is then carried out, with redistribution of the engine drag torque from the transmission input shaft 1 to the transmission input shaft 2. For this purpose, reference is made to the clutch torque curves drawn by. If in addition the crankshaft starter generator is used in the manner described, a "drive drag torque" that increases linearly in phase II is achieved to a certain extent in phase II, and the torque transmission capacity of the clutch 1 must be increased at least to the extent that the clutch arrangement 1 must be increasingly engaged that the total drag torque from the drag torque of the engine and the drag torque of the crankshaft starter generator can be transmitted to the transmission input shaft 1.

In phase III, the braking torque and - if used - the Drag torque of the crankshaft starter generator is reduced again to the course of the longitudinal vehicle acceleration shown in the diagram to obtain. It should also be added that two variants are shown are: According to the solid longitudinal acceleration curve to which the solid torque curve for the clutch assembly 2 is heard a transition phase extending over phases II, III and IV aims. According to the longitudinal acceleration curve shown in dashed lines the torque curve shown in dashed lines for the clutch assembly 2 belongs, the transition phase extends only to phases II and III.

The exemplary embodiment in FIG. 15 is primarily intended to show by way of example how a brake-generated gradient phase which precedes (or follows) the actual overlap phase can be used in order to achieve a transition phase which is significantly longer than the overlap circuit phase.

Among other things, a method for operating a contract is proposed drive train and a drive train with a the invention Procedure performing control unit. According to one aspect of the invention it is provided that at least in an operating state of a train Operating state and a coasting operating state of the drive train assigned when switching between a first transmission input shaft Neten first gear and a second transmission input shaft ordered second gear assigned to the first transmission input shaft  Nete clutch assembly and one of the second transmission input shaft assigned clutch arrangement actuated in this way and a drive unit-comprehensive torque generation arrangement is controlled in such a way that at least one of the following criteria relating to one of the Switching comprehensive switching sequence is fulfilled: 1) during switching at least approximately occurs on the transmission output shaft moment that remains constant or changes monotonously, 2) while During the switching sequence, an essentially monotonically increasing or essentially monotonically decreasing vehicle acceleration enough.

Claims (66)

1. A method for operating a drive train belonging to a motor vehicle, which has:
a torque generation arrangement ( 12 , 50 ) which comprises at least one drive unit ( 12 ), optionally in the form of an internal combustion engine ( 12 ), and, if desired, an auxiliary unit ( 50 ) for generating an auxiliary torque;
a gearbox ( 18 ) having a synchronization device ( 52 ) with at least two gearbox input shafts ( 20 , 22 ) and at least one gearbox output shaft ( 54 ), a first gearbox input shaft ( 20 ) having at least a first gear and a second gearbox input shaft ( 22 ) having at least a second gear assigned;
a between the drive unit ( 12 ) and the transmission ( 18 ) arranged multiple clutch device ( 24 ), if necessary double clutch device ( 24 ), for torque transmission between the drive unit ( 12 ) and the transmission ( 18 ), which is one of the first Transmission input shaft ( 20 ) assigned first clutch arrangement ( 26 ) and one of the second transmission input shaft ( 22 ) assigned second clutch arrangement ( 28 ), the two clutch arrangements being operable independently of one another;
characterized in that at least in an operating state of a train operating state and a pushing operating state of the drive train or of the motor vehicle, when switching between a first gear and a second gear, actuates the clutch arrangements ( 26 , 28 ) and the torque generation arrangement ( 12 , 50 ) are controlled in such a way that at least one of the following criteria with regard to a switching sequence comprising the switching is fulfilled:

• a) during the shift sequence, a monotonically changing torque, which is imparted at least partially from the transmission ( 18 ) to the transmission output shaft ( 54 ) and acts on the vehicle in terms of acceleration or deceleration, occurs on the transmission output shaft ( 54 ) or on the output side thereof, in a transition phase, wherein preferably a difference between a torque value at the beginning of the transition phase and a torque value at the end of the transition phase essentially corresponds to a change in the transmission ratio when shifting,
• b) during the shift sequence, the torque occurring at the transmission output swelle ( 54 ) or on the output side thereof, at least partially mediated by the transmission ( 18 ) to the transmission output shaft ( 54 ), remains essentially constant before and after the transition phase,
• c) during the shift sequence, an essentially constant transmission input, corresponding to a sum of a first torque contribution introduced via the first transmission input shaft and a second torque contribution initiated via the second transmission input shaft, is introduced into the transmission via the transmission input shafts,
• d) an essentially monotonically increasing or essentially monotonously decreasing vehicle acceleration is achieved during the switching sequence.

2. The method according to claim 1, characterized in that during of the switching sequence, criterion a) is fulfilled. 3. The method according to claim 1, characterized in that during of the switching sequence, criteria a) and b) are met together.   4. The method according to any one of claims 1 to 3, characterized in net that criterion c) is met during the switching process. 5. The method according to any one of claims 1 to 4, characterized in net that criterion d) is met during the switching process. 6. The method according to any one of claims 1 to 5, characterized in net that the at least one criterion when upshifting a lower gear (exit gear) to a higher gear (Finish line) is fulfilled. 7. The method according to any one of claims 1 to 6, characterized in net that the at least one criterion when downshifting a higher gear (exit gear) to a lower gear (Finish line) is fulfilled. 8. The method according to any one of claims 1 to 7, characterized in net that the at least one criterion both in train operation condition as well as in the overrun operating condition. 9. The method according to any one of claims 6 to 8, characterized in net, that the shift sequence before engaging the target gear Actuation of the clutch arrangement assigned to the target gear in For the purposes of extensive or complete disengagement (Phase I). 10. The method according to any one of claims 6 to 9, characterized in net that the switching sequence before or / and while inserting the Target gear an actuation of the assigned to the output gear Coupling arrangement in the sense of a reduction of the clutch transferable moments (phase II).   11. The method according to claim 10, characterized in that in the Train operating state that is transferable from the clutch arrangement Moment is set to a value that is about the current or previously prepared from the torque generation arrangement set moment (phase (I). 12. The method according to claim 10 or 11, characterized in that in the overrun mode from the clutch assembly transmittable moment is set to a value that amount moderately below the current or previous of the moments generation arrangement provided moment (phase II). 13. The method according to any one of claims 6 to 12, characterized records that the switching sequence before or / and during or / and after a control of the torque generation when the target gear is engaged arrangement in the sense of an increase or decrease of a torque provided by the torque generation arrangement comprises (phases II, III). 14. The method according to any one of claims 6 to 13, characterized records that a moment contribution due to a in the course of Engaging the target gear acceleration or braking solution of a rotating mass arrangement is compensated by setting a corresponding compensation moment contribution from the Torque generation arrangement or / and by corresponding Actuation of the clutch arrangement assigned to the output gear (Phase II). 15. The method according to any one of claims 6 to 14, characterized indicates that the clutch arrangement assigned to the output gear is brought into a slip state and then the already engaged target gear assigned clutch arrangement in the  Meaning of a clutch and the one assigned to the exit gear Coupling arrangement in the sense of disengaging is actuated (Pha sen II, III). 16. The method according to claim 15, characterized in that the Actuation of the clutch arrangements coordinated takes place such that one of the clutch arrangements as a whole transmitted torque remains essentially constant (phase III). 17. The method according to claim 15 or 16, characterized in that the actuation of the clutch arrangements coordinated takes place in such a way that a selected slip speed is constant will (phase III). 18. The method according to claim 16 or 17, characterized in that the clutch arrangement assigned to the target gear is controlled in The sense of engaging is actuated and the exit gear assigned clutch arrangement regulated in terms of Auskup pelns is pressed (phase III). 19. The method according to claim 16 or 17, characterized in that controlled the clutch assembly associated with the output gear is actuated in the sense of disengaging and the target gear orderly clutch arrangement regulated in the sense of engaging is operated (phase III). 20. The method according to any one of claims 6 to 19, characterized records that in the train operating state in the train or after a Setting the clutch arrangement assigned to the target gear transferable torque to a value that is approximately equal to the moment tan or prior to the torque generation arrangement provided torque corresponds to the torque generation arrangement  in the sense of a reduction in the amount provided by the latter Moments is driven to a speed of the torque generation supply arrangement to a speed assigned to the target gear At least approximate the transmission input shaft (phase IV). 21. The method according to any one of claims 6 to 20, characterized records that in the overrun mode in the train or after an adjustment of the clutch assigned to the target gear arrangement of transferable moments to a value which is approximately that currently or previously from the torque generation arrangement provided moment corresponds to the moment generation arrangement controlled in such a way and / or assigned to the target gear Nete clutch assembly is operated such that this Coupling arrangement transmissible torque is larger in amount than one of the torque generation arrangement at the same time set torque to a speed of torque generation a speed of the gearbox assigned to the target gear at least approximate the gear shaft (phase IV). 22. The method according to claim 20 or 21, characterized in that a moment contribution due to one in the course of the approximation of the Speeds occurring acceleration or deceleration of a Rotational mass arrangement is compensated, if necessary by Setting of a corresponding compensation moment contribution the torque generation arrangement (phase IV). 23. The method according to any one of claims 20 to 22, characterized records that in the course of or after the approximation of the speed of the Torque generation arrangement to the speed of the target gear assigned transmission input shaft that assigned to the target gear Coupling arrangement is essentially completely engaged (Phase V).   24. The method according to any one of claims 20 to 23, characterized records that in the course of or after the approximation of the speed of the Torque generation arrangement to the speed of the target gear assigned transmission input shaft to the output gear orderly clutch arrangement is engaged at least as far as that a speed of the gear assigned to the output gear input shaft to the speed of the assigned to the target gear Transmission input shaft is at least approximated (phase V). 25. The method according to claim 24, characterized in that a Moments contribution due to one in the course of the approximation of the rotation numbers occurring acceleration or deceleration of a turn mass arrangement is compensated by setting an ent speaking compensation moment contribution of the moment generators supply arrangement (phase V). 26. The method according to any one of claims 20 to 25, characterized records that in the course of or after the approximation of the speed of the Torque generation arrangement to the speed of the target gear assigned transmission input shaft the torque generation order is controlled in such a way that it provides a moment, that from the torque generation arrangement before switching process provided at least approximately (phase V). 27. The method according to any one of claims 1 to 26, characterized draws that ready from the torque generation arrangement set moment in at least one shift sequence phase (phases II, III, IV, V) a torque provided by the drive unit Contribution and a moment provided by the auxiliary unit contribution includes.   28. The method according to claim 27, characterized in that both Posts are positive or that both posts are negative or that one contribution is positive and the other contribution is negative. 29. The method according to any one of claims 1 to 28, characterized in that a crankshaft starter generator ( 50 ) and / or a brake arrangement is used as the auxiliary unit. 30. The method according to any one of claims 1 to 29, characterized in that the transition phase is essentially formed by an overlap circuit phase (phase III in Fig. 2, 3 and 5), in which the clutch arrangements are actuated in opposite directions to a between to shift the drive unit and the transmission to be transmitted torque from the transmission input shaft assigned to the output gear to the transmission input shaft assigned to the target gear. 31. The method according to any one of claims 1 to 29, characterized in that the transition phase is essentially formed by an overlap circuit phase (phase III in Fig. 4; phase B), in which the clutch arrangements are actuated in opposite directions to one between the drive unit and to transfer the torque to be transmitted from the transmission input shaft assigned to the output gear to the transmission input shaft assigned to the target gear, and from a gradient phase preceding the overlap shift phase (phase II in FIG. 4; phase A) or / and a gradient phase following the overlap shift phase (Phase C), in which a monotonous change in the torque acting on the vehicle, possibly the torque occurring at the transmission output shaft, is effected by corresponding activation of the torque generation arrangement and / or by corresponding actuation of the clutch assigned to the output gear or the target gear ngsanordnung. 32. The method according to claim 30 or 31, characterized in that in the overlap shift phase (phase B) the clutch arrangements are controlled in such a way that a strictly monoto ne, preferably an at least approximately linear change of the torque occurring at the transmission output shaft is reached becomes. 33. The method according to claim 31 and 32, characterized in that precede the overlap switching phase (phase B) the gradient phase (phase A) and / or in the overlap switching phase subsequent gradient phase (phase C) Torque generation arrangement so controlled and / or clutch assigned to the starting gear or the target gear arrangement is operated in such a way that a strictly monotonous, preferred indicate an at least approximately linear change in the Acting vehicle, possibly on the transmission output shaft occurring moment is reached. 34. The method according to claim 33, characterized in that the control or actuation is such that over the entire transition phase (phase A + B + C; phase II + III in Fig. 4; phase B + C) strictly monotonous, preferably an at least approximately linear change in the torque acting on the vehicle and possibly occurring on the transmission output shaft. 35. The method according to any one of claims 31 to 34, characterized records that the monotonous, possibly strictly monotonous or linear change in the force acting on the vehicle, if necessary  on the transmission output shaft torque in the Overlap circuit phase (phase B) previous Gra service phase (phase A) and / or in the overlap scarf tion phase subsequent gradient phase (phase C) set is based on a change resulting from the change in transmission setting when changing a change in the transmission output shaft occurring moments. 36. The method according to claim 35, characterized in that the monotonous, possibly strictly monotonous or linear change the one acting on the vehicle, possibly on the transmission gangswelle occurring moments in the gradient concerned phase (phase A or C) is set on the basis of a Torque target gradients or acceleration target gradients or / and a predetermined period of time for the overlap circuit phase and / or a predetermined period of time for the relevant gradient phase and / or a predetermined period of time for the transition phase and / or one assigned to the exit corridor Neten gear ratio and / or the target gear orderly gear ratio and / or a current An drive torque or drag torque of the drive unit or / and a desired drive torque or drag torque Drive unit. 37. The method according to any one of claims 31 to 36, characterized indicates that when shifting up from a lower gear (off gait aisle) to a higher aisle (target aisle) in the train operating a drive torque provided by the drive unit or / and that of the clutch assigned to the output gear arrangement transmitted or transferable moment in the of the over intersection circuit phase (phase B) preceding gradients tenphase (phase A) monotonous, preferably strictly monotonous,  most preferably linear, from an initial value to one Intermediate value is lowered. 38. The method according to claim 37, characterized in that in the Overlap circuit phase (phase B) that of the drive unit provided drive torque from the intermediate value mo noton, preferably strictly monotonous, most preferably linear, is raised. 39. The method according to claim 38, characterized in that the of drive torque provided to the drive unit in the over cut circuit phase (phase B) for another intermediate value is raised above the initial value and preferred wise in the course of the overlap shift phase gradient phase (phase C) from the further intermediate value if desired, at least close to the initial value approximately corresponding final value is brought. 40. The method according to claim 39, characterized in that the of the drive torque provided to the drive unit in the over the subsequent gradient phase (phase C) from the further intermediate value first to a value below the Output value is brought and then raised to the final value or / and that a clutch assigned to the target gear transmitted or transferable moment in the Overlap circuit phase subsequent gradient phase (Phase C) of an intermediate value at the end of the overlap First, the switching phase is monotonous, preferably strictly mono tone, most preferably linear, is lowered, and then given is raised again, especially after that of the Drive unit provided torque has reached the end value.   41. The method according to any one of claims 31 to 40, characterized records that when shifting down from a higher gear (Exit gear) to a lower gear (finish gear) in the train loading area drive state a drive provided by the drive unit moment or / and that of the assigned to the output gear Coupling arrangement transmitted or transferable moment in the preceding the overlap switching phase (phase B) Gradient phase (phase A) monotone, preferably strictly monotone, most preferably linear, from an initial value to one Intermediate value is raised. 42. The method according to claim 41, characterized in that in the Overlap circuit phase (phase B) that of the drive unit provided drive torque from the intermediate value mo noton, preferably strictly monotonous, most preferably linear, is lowered. 43. The method according to claim 42, characterized in that the of drive torque provided to the drive unit in the overlap identification circuit phase (phase B) to another intermediate value is lowered below the initial value and preferably in Course of those following the overlap switching phase Gradient phase (phase C) from the further intermediate value if desired, at least approximate the initial value corresponding final value is brought. 44. The method according to claim 43, characterized in that one of the clutch arrangement assigned to the target gear or transferable moment in that of the overlap circuit phase (phase B) subsequent gradient phase (phase C) of the intermediate value at the end of the overlap circuit phase monotone, preferably strictly monotone, most preferably  linearly to another, possibly the final value the intermediate value is raised, and then possibly further is raised, especially after that from the drive unit provided moment has reached the final value. 45. The method according to any one of claims 31 to 44, characterized records that when shifting down from a higher gear (Exit gear) to a lower gear (finish gear) in the overrun Operating state a tow applied by the drive unit moment in the overlap switching phase (phase B) of an initial value monotone, preferably strictly monotone, most preferably linear, is reduced to an intermediate value. 46. The method according to claim 45, characterized in that the of the drive unit applied drag torque in the course of the Overlap circuit phase (phase B) subsequent gradients first phase (phase C) is further reduced from the intermediate value and then, if desired, at least the initial value approximately corresponding end value is brought. 47. The method according to claim 46, characterized in that one of the clutch arrangement assigned to the target gear or transferable moment in that of the overlap circuit phase (phase B) subsequent gradient phase (phase C) of an intermediate value at the end of the overlap switching phase monotone, preferably strictly monotone, most preferably linear to another, possibly the amount of the final value corresponding intermediate value is raised, and then given is further raised, especially after that of the Drive unit applied drag torque reaches the final value Has.   48. The method according to any one of claims 31 to 47, characterized in that when shifting up from a lower gear (starting gear) to a higher gear (target gear) in the overrun condition, a drag torque applied by the drive unit in the Gra preceding the overlap shift phase serving phase is monotonous, preferably strictly monotonous, most preferably linear, is reduced from an initial value to an intermediate value and / or that the torque transmitted or transmissible by the clutch arrangement assigned to the output gear is in the gradient phase preceding the overlap shift phase (phase III in FIG. 4) ( Phase II in FIG. 4) is reduced mono-tone, preferably strictly monotone, most preferably linear, from an initial value to an intermediate value. 49. The method according to claim 48, characterized in that the amount assigned by the clutch arrangement assigned to the output gear via portable torque in the gradient phase (phase II in FIG. 4) is reduced below the drag torque applied by the drive unit. 50. The method according to any one of claims 1 to 49, characterized records that the transition phase is at least partially formed from a braking phase in which a monotonous change of the to the Acting vehicle is caused by appropriate Actuation of a / the brake assembly of the vehicle, possibly on the wheels of the vehicle acting vehicle brakes, preferably wise at least in a partial phase of the braking phase in coordination upon actuation of at least one of the clutch arrangements. 51. The method of claim 50 and claim 31, characterized characterized that the overlap circuit phase preceding gradient phase and / or that of the overlap  circuit phase subsequent gradient phase at least partially is formed by a braking phase and / or that the overlap circuit phase includes a braking phase or deals with a Braking phase overlaps. 52. The method according to any one of claims 1 to 51, characterized in that a braking torque of the drive unit occurring in a coasting operating state in at least one phase (phases II and III in Fig. 11 to 13) of the switching sequence by one of the / Brake arrangement of the vehicle, preferably by at least partially replaced by a from the vehicle brakes acting on the vehicle brakes brought up replacement braking torque. 53. The method according to claim 52, characterized in that a Substitution is provided such that i) previously the braking torque of the drive unit in the transmission introductory clutch arrangement assigned to the output gear in terms of disengagement and ii) the brake arrangement in terms generation of the replacement braking torque is actuated. 54. The method according to claim 53, characterized in that at least at least initially that the equivalent braking torque to that of the previous transmit clutch arrangement assigned to the output gear Necessarily corresponds to braking torque, this clutch arrangement as a result of actuation in the sense of disengagement preferably no longer transmits an essential moment, or that at least initially a total braking torque from the replacement Braking torque and one of the assigned to the output gear Coupling arrangement still transmitted residual torque essentially Chen that previously of the Kup assigned to the exit aisle planning arrangement corresponds to the braking torque.   55. The method according to any one of claims 52 to 54, characterized records that the replacement braking torque is continuously reduced is coordinated with an actuation of the target gear Neten clutch assembly in the sense of engaging and / or on a change in a torque provided by the drive unit moments in the sense of reducing a positive moment tanen drive torque of the drive unit or in the sense of a Increase in an instantaneous braking torque of the drive Ness. 56. The method according to claim 55, characterized in that the The replacement braking torque is reduced in such a way that the total braking torque acting on the vehicle due to the instantaneous moments and provided by the drive unit the instantaneous braking effect of the brake arrangement monotonously, preferably changes strictly monotonously. 57. The method according to claim 56, characterized in that the Replacement braking torque according to a continuous change of the introduced into the transmission via the coupling device Moments due to the provided by the drive unit Moments is reduced and then preferably essentially disappears when the clutch arrangement assigned to the target gear Essentially complete the or a predetermined brake torque of the drive unit transmits. 58. The method according to any one of claims 52 to 57, characterized records that in the overrun mode in preparation for a Downshifting from a higher gear (exit gear) to a lower gear (target gear) in a preparatory phase of the Shift sequence the clutch arrangement assigned to the output gear essentially completely disengaged, the drive unit for  Providing a positive drive torque and the the target gear associated clutch assembly in a Be accelerating torque transmitting, a partial indentation the clutch arrangement corresponding partial engagement state ge is brought in such that the gearbox assigned to the target gear is inserted gear shaft mediating this clutch arrangement on the ground position of the positive drive torque together with the drive unit itself in the direction of a syn chrome speed is accelerated. 59. The method according to claim 58, characterized in that the Target gear is engaged when the speed of the target gear assigned transmission input shaft the synchronous speed in the We achieved significantly or according to a predetermined Threshold differential speed interval approximate the synchronous speed has. 60. The method according to claim 59, characterized in that late at least after the target gear is engaged, the drive unit in the sense a reduction in the positive drive torque and the readiness Position of a braking torque is controlled, preferably the torque provided by the drive unit continuously is changed until the braking torque provided a predetermined value, if applicable the one prevailing at the beginning of the switching sequence Value. 61. The method according to any one of the preceding claims, characterized in that a distinction is made between first and second train operating states, wherein for first train operating states when switching between the first gear and the second gear in the sense of an upshift or / and in the sense of a Downshifting, the clutch assemblies ( 26 , 28 ) are actuated and the torque generating assembly ( 12 , 50 ) are actuated such that at least one of the criteria a) to d) with respect to the shift sequence is met, and for second train operating states below Dispensing with the fulfillment of at least one of the criteria a) to d) in relation to the switching sequence, the switching sequence is carried out in such a way that an interruption in tractive force occurs. 62. The method according to any one of the preceding claims, characterized in that a distinction is made between first and second overrun operating states, wherein for first overrun operating states when switching between the first gear and the second gear in the sense of an upshift or / and in the sense of downshifting, the clutch arrangements ( 26 , 28 ) are actuated and the torque generation arrangement ( 12 , 50 ) are controlled such that at least one of the criteria a) to d) with respect to the switching sequence is fulfilled, and wherein for second overrun operating conditions without fulfilling at least one of the criteria a) to d) with respect to the shift sequence, the shift sequence is carried out in such a way that an interruption in thrust occurs. 63. Drive train, optionally in a motor vehicle, comprising:
a torque generation arrangement ( 12 , 50 ) which comprises at least one drive unit ( 12 ), optionally in the form of an internal combustion engine ( 12 ), and, if desired, an auxiliary unit ( 50 ) for generating an auxiliary torque;
a gearbox ( 18 ) having a synchronization device ( 52 ) with at least two gearbox input shafts ( 20 , 22 ) and at least one gearbox output shaft ( 54 ), a first gearbox input shaft ( 20 ) having at least a first gear and a second gearbox input shaft ( 22 ) having at least a second gear assigned;
a between the drive unit ( 12 ) and the transmission ( 18 ) arranged multiple clutch device ( 24 ), if necessary double clutch device ( 24 ), for torque transmission between the drive unit ( 12 ) and the transmission ( 18 ), which is one of the first Transmission input shaft ( 20 ) assigned first clutch arrangement ( 26 ) and one of the second transmission input shaft ( 22 ) assigned second clutch arrangement ( 28 ), the two clutch arrangements being operable independently of one another;
characterized by a drive unit assigned control unit ( 36 ), which is set up in connection with a shift between a first and a second gear to maintain an at least approximately constant, mediated by the transmission ( 18 ) to the transmission output shaft ( 54 ) Moments on the transmission output shaft ( 54 ) before and after a transition phase in which a monotonous change in the torque transmitted from the transmission ( 18 ) to the transmission output shaft ( 54 ) preferably occurs essentially in accordance with the change in the transmission ratio when shifting, and / or to achieve it an essentially monotonically increasing or essentially monotonously decreasing vehicle acceleration and / or to achieve the desired driving comfort, to control the torque generation arrangement according to the method according to one of the preceding claims and the coupling device according to the method according to one of the preceding claims To make claims. 64. Drive train according to claim 63, characterized in that the auxiliary unit is a crankshaft starter generator ( 50 ) and / or a brake arrangement is used as the auxiliary unit. 65. Drive train according to claim 63 or 64, characterized in that the clutch arrangements are designed as wet-running multi-plate clutch arrangements ( 26 , 28 ). 66. Drive train according to claim 63 or 64, characterized in that the clutch assemblies as a dry-running clutch Arrangements are preferably made of the friction disc type.