DE10361299A1 - Switching method for an automated switching claw transmission - Google Patents

Abstract

The The invention relates to a shifting method for an automated manual transmission with dog clutch. In this switching method is closed Main clutch switched to reduce wear and quickly to be able to switch. If one for this Switching process essential Signal of a speed sensor of the transmission input shaft a faulty Signal delivers, takes over with closed main clutch substitute a speed sensor for the crankshaft speed this function.

Description

The Invention relates according to claim 1 a drive train and according to claim 4 a control method for such a.

One Such a drive train or such a control method is already known from WO 02/060715 A1, which discloses a method of operation a powertrain of a motor vehicle describes in which at each gear change depending measured operating variables of the motor vehicle It is decided whether a clutch is opened during the gear change or remains closed. At a gear change with closed Clutch is the synchronization of a speed of a transmission input shaft to a target speed in the target gear also by means of an influence of the drive motor. The gear change is dependent from a signal of a speed sensor for the transmission input shaft. In this drive train is also a drive motor speed sensor intended.

In the EP 0 695 665 A1 a method for operating a drive train of a motor vehicle with an automated transmission in the form of an automatic transmission is described. The transmission can be connected by means of an automated clutch with a drive motor. Each time the transmission is changed, the clutch is opened and closed again when the gear change is complete. This leads to a heavy wear on the clutch, in particular, when the drive train is used in a commercial vehicle with a large vehicle mass and high mileages.

In the EP 0 676 566 A1 a method for operating a powertrain of a motor vehicle with an automated transmission is described. The transmission can be connected by means of a fußkraftbetätigten or an automated clutch with a drive motor. In the described method, gear changes of the transmission are carried out from a source to a target gear with the clutch engaged. The synchronization of a speed of a transmission input shaft to a target speed in the target gear by means of influencing the drive motor. Upon request of an upshift, for example, by the driver, it is determined based on currently detected vehicle operating conditions, whether the requested upshift is feasible. Only feasible gear changes are triggered, requirements for unachievable gear changes are modified or deleted. Thus, a variety of gear changes, which would be feasible with the clutch open, not performed.

The non-Japanese JP 01-129892 and JP 01-136349 relate to Evaluation of an abnormal value of a transmission input shaft sensor of a Planetary automatic transmission with hydrodynamic torque converter.

The EP 0 241 216 B1 relates to a method of controlling an automatic mechanical transmission in which a program is modified by ignoring an identified, erroneous input signal and processing the remaining input signals in accordance with predetermined logical rules.

The DE 42 37 983 C2 relates to a method for automatically controlling a friction clutch. An emergency mode is provided for the failure of the motor sensor.

task The invention is to provide a reliable or fail-safe To create a powertrain.

According to one Advantage, the drive train on a Schaltklauengetriebe. One Such shift dog transmission is due to the omission of synchronizer rings subjected to no frictional wear, so that the switching elements designed as switching jaws for inserting and laying out the corridors are durable.

According to the invention the engagement the two Schaltklauenhälften in contrast to completely unsynchronized Schaltklauengetrieben almost jerk-free and therefore non-destructive, there the drive motor control and possibly an additional central synchronization during gear change the speeds of the gear shafts aligns with each other.

This central synchronization can be carried out in a particularly advantageous manner such that the drive motor performs the speed matching. That is, when upshifting the drive shaft speed of the drive motor is lowered and the downshift, the drive shaft speed of the drive motor is raised. For this purpose, the drive motor has actuators, which are controlled by a control device. For example, the control device can specify an injection quantity of a fuel, an ignition point or the use of so-called engine brakes, for example in the form of an exhaust flap or a constant throttle. The actuators of Schaltklauengetriebes and the clutch can also be controlled by said control device or by a further control device. The control devices are there when in signal connection.

The Control device of Schaltklauengetriebes can in dependence Selection rules and vehicle parameters and / or operating variables of Motor vehicle make a selection, whether in a gear change the clutch is open is or remains closed.

If Gear change from an original gear in a target gear of Schaltklauengetriebes with closed clutch performed be done after laying out the original gear, if so no connection between an input and an output shaft the shift doggearing consists, a speed equalization of the transmission input shaft to a target speed in the target gear, the so-called synchronous speed, by influencing the drive motor. At synchronous speed have switching elements of the target gear, which on the one hand with the transmission input shaft and on the other hand with the transmission output shaft and thus with driven vehicle wheels are connected, the same speed. With downshifts is to from requested a torque to the control device of the drive motor, by means of which the speed of the drive motor and thus also the Speed of the transmission input shaft is increased. For upshifts is a very low or a negative, a so-called push moment, requested to reduce the speed of the transmission input shaft. To support this, you too can the said engine brakes or more, not the drive motor belonging Retardants, For example, a transmission brake to be controlled.

For the speed adjustment Consequently, the knowledge of the transmission input shaft speed is necessary. For this purpose, a speed sensor according to the invention provided, the one representing the transmission input shaft speed Value determined. This is most advantageously a speed sensor, the speed decreases directly from the transmission input shaft. This speed sensor is also called the transmission input shaft speed sensor designated. Similarly, the speed sensor for determining the transmission input shaft speed the latter of a coupling half Remove the clutch that is directly connected to the transmission input shaft rotatably or with interposition a torsion damper is coupled. For a countershaft transmission with one or more constants the speed sensor can advantageously also on the countershaft be arranged, since then a fixed speed ratio between the countershaft and the transmission input shaft is present. In a countershaft transmission with several - in particular two - constants can the transmission input shaft speed in knowledge of each in the Force flow constant over a the countershaft speed decreasing speed sensor can be determined. The speed sensor can depending on the geometric or thermal installation conditions be arranged on a main shaft whose gear with a Gear of the main shaft meshes.

• – ausfällt oder
• – ein unsinniges Signal liefert

wird vom Steuergerät, dass die Gangwechsel bei geschlossener Kupplung steuert, erfindungsgemäß ein Ersatzsignal herangezogen bzw. generiert. Dieses Ersatzsignal stammt von einem weiteren Drehzahlsensor, der antriebsmotorseitig von der Kupplung liegt. Damit wird dem Umstand Rechnung getragen, dass bei geschlossener Kupplung die Antriebsmotordrehzahl zumindest näherungsweise gleich der Getriebeeingangswellendrehzahl ist. Ein eventueller Kupplungsschlupf kann dabei durch einen Ausgleichsfaktor kompensiert werden. Dieser Ausgleichsfaktor kann parameterabhängig sein. So kann der Ausgleichsfaktor beispielsweise abhängig von dem Motormoment sein, dass das Motorsteuergerät liefert und/oder der Ausgleichsfaktor ist abhängig von

• – der Anpressung oder
• – dem Ausrückweg,

der im Steuergerät der automatisierten Kupplung abgelegt ist.In the event of a fault, ie when this transmission-side speed sensor

• - fails or
• - provides a nonsensical signal

is used by the control unit that controls the gear change when the clutch is closed, according to the invention, a substitute signal or generated. This replacement signal comes from another speed sensor, the drive motor side of the clutch is located. Thus, the fact is taken into account that when the clutch is closed, the drive motor speed is at least approximately equal to the transmission input shaft speed. A possible clutch slip can be compensated by a compensation factor. This compensation factor can be parameter-dependent. For example, the compensation factor may be dependent on the engine torque that the engine control unit supplies and / or the compensation factor depends on

• - the pressure or
• - the Ausrückweg,

which is stored in the control unit of the automated clutch.

Of the additional speed sensor for the substitute signal can in particular the speed sensor of the drive motor Preferably, the drive motor speed of an incremental decreases on the flywheel of the crankshaft. However, it is also possible as another speed sensor to take the OT sensor, its signal transmitter rotates at half crankshaft speed and over a doubling of this Sensor signal over the time to determine the transmission input shaft speed. The OT sensor is not a speed sensor in the true sense, but the Sensor for the control of the drive motor ignition determines the top dead center directly or indirectly on the camshaft. The OT sensor delivers due to the halved speed and the lower Number of increments or signal generators, although an inaccurate value, as the speed sensor of the drive motor. This inaccurate value is however for the failure of the failure of the actual transmission-side speed sensor acceptable because the failure is displayed or stored in the fault memory can be and the next routine workshop visit the transmission-side speed sensor is changed.

• – Lastanforderungssignal, d.h. α und
• – Kurbelwellendrehzahl, d.h. n

arbeitet, als Eingangsgröße anstelle der Kurbelwellendrehzahl die Getriebeeingangswellendrehzahl. Ein solches Notlaufprogramm für den Antriebsmotor steuert den Antriebsmotor in vorteilhafter Weise relativ genau.In a further embodiment of the inventions tion, it is also possible that the transmission-side speed sensor takes over its function in case of failure of the drive motor side speed sensor. Thus, for example, in case of failure of the crankshaft speed sensor while driving with the clutch engaged or during a gear shift with the clutch engaged, the transmission input shaft speed sensor can take over the function of the crankshaft speed sensor. Thus, the control of the drive motor, which basically as α-n control depending on the input parameters

• Load request signal, ie, α and
• - Crankshaft speed, ie n

works as input instead of the crankshaft speed, the transmission input shaft speed. Such an emergency program for the drive motor controls the drive motor in an advantageous manner relatively accurately.

• – wenn der getriebeseitige Drehzahlsensor ausfällt, liefert der antriebsseitige Drehzahlsensor das Ersatzsignal für den getriebeseitigen Drehzahlsensor und
• – wenn der antriebseitige Drehzahlsensor ausfällt, liefert der getriebeseitige Drehzahlsensor das Ersatzsignal für den antriebsseitigen Drehzahlsensor.

In a particularly advantageous embodiment of the invention, controls or a control of the drive train may be provided, in each of which a speed sensor for the other speed sensor provides a replacement signal and / or comparison signal for error evaluation. that is,

• - If the transmission-side speed sensor fails, the drive-side speed sensor provides the replacement signal for the transmission-side speed sensor and
• - If the drive-side speed sensor fails, the transmission-side speed sensor provides the replacement signal for the drive-side speed sensor.

The Deficiency of a signal of the transmission-side speed sensor and / or the drive-side speed sensor can be particularly advantageous Way over the comparison of the two speed sensor signals together. Thus, both an error of the crankshaft speed sensor for Control of the drive motor as well as a failure of the transmission input shaft speed sensor for controlling the switching operations be determined. Which of the two speed sensors or which Signal of the two speed sensors is faulty, for example, via a Comparison of the signals with the signal of the aforementioned OT sensor done. To determine the crankshaft speed by means of the OT signal must the latter of the control device, for example, the drive motor or the Schaltklauengetriebes over the Time to be considered.

gear shift or switching operations can both from a driver by means of a suitable actuator in a manual mode, for example with a shift lever, or in an automatic mode by the controller of the shift doggear be requested.

It can also gear changes or switching operations performed with open coupling become. When the clutch is open, no torque can be transmitted from the transmission input transferred to the transmission output shaft become. For this it is not necessary that a actuation path the clutch was completely passed through.

In order to can each gear change or switching operation with respect to the Operating conditions of the motor vehicle suitable coupling state carried out become. This is a reliable one Operation of the powertrain, at which requested gear changes the shift doggear are safely executed, guaranteed. At the same time there is less wear on the clutch and thus a cost-effective Operation of the motor vehicle allows.

Besides, they are when open Clutch so gear change possible, in which the speed of the drive motor in the target gear is less than the so-called idle speed is, so the speed that is without Intervention of the driver idle when stationary. This can be done, for example, before Entering a steep grade or a steep grade of Be an advantage.

• – nach einer Erstinbetriebnahme des Antriebsstrangs und/oder
• – nach einem Start des Antriebsmotors und/oder
• – bei einer erkannten Fehlfunktion einer Komponente des Antriebsstrangs mit Ausnahme des getriebeseitigen und/oder antriebsseitigen Drehzahlsensors

In a particularly advantageous embodiment of the invention are in a period of time

• After a first commissioning of the drive train and / or
• After a start of the drive motor and / or
• - With a detected malfunction of a component of the drive train with the exception of the transmission-side and / or drive-side speed sensor

• – einer Erstinbetriebnahme des Antriebsstrangs und/oder
• – einem Start des Antriebsmotors

werden insbesondere Hochschaltungen mit geöffneter Kupplung durchgeführt.Gear change performed with the clutch open. To

• - A first commissioning of the powertrain and / or
• - a start of the drive motor

In particular, upshifts are performed with the clutch open.

Under a commissioning is the commissioning of the powertrain after the manufacture of the motor vehicle or commissioning after an exchange of an element, for example the drive motor, understood the drive train. The time span can be fixed be or after fulfillment some conditions are ended.

At a first start-up or after a start of the drive motor are not all driving tool parameters, which are taken into account in the selection and the mentioned test, known. For example, during a first commissioning, the course parameters of the rotational speed of the drive motor may be unknown. These can then be measured and stored in a control device. After an engine start, for example, the vehicle weight may have changed very much due to a change in the payload. This is the case in particular for commercial vehicles, in which the payload can far exceed a curb weight of the vehicle.

A Condition for ending the said period of time, for example be that all for the selection of relevant vehicle parameters are determined.

So long the vehicle parameters are not determined, can not be secured Selection performed become. This will be in this phase by changing gears with open Clutch ensures a secured operation of the motor vehicle.

In a particularly advantageous embodiment of the invention can at a detected malfunction of a component of the powertrain with the exception of the failure of the transmission side and / or the drive side Speed sensor the switching operations also be done with an open coupling. For example the control device of the drive motor can detect a defect and then only an emergency operation of the drive motor guarantee. Furthermore, for example, an engine brake can be so stiff, that the operation of the engine brake is no longer or only to a very limited extent possible.

The Behavior of the faulty component during a gear change is thus unpredictable. Thus, no assured examination and selection carried out become. This is due to detected malfunction of a component Gear change with open clutch a secured operation of the motor vehicle guaranteed.

In Embodiment of the invention takes the control device in dependence of validation rules an exam before, whether a requested gear change when the clutch is closed is feasible. The choice of whether the clutch is opened during the gear change or remains closed depends on the result of the test. In particular, all possible gear change with closed clutch also so executed. This is one possible size Number of gear changes with closed clutch performed what leads to a particularly low wear on the coupling.

• – ein Fahrzeuggewicht,
• – ein Luftwiderstandsbeiwert und eine Stirnfläche,
• – Rollwiderstandskoeffizienten der Fahrzeugreifen,
• – Verlaufsparameter der Drehzahl des Antriebsmotors beim Synchronisieren während eines Gangwechsels, beispielsweise ein maximaler positiver und negativer Gradient oder
• – ein Allgemeinzustand der Motorbremsen, beispielsweise leicht- oder schwergängig.

In an embodiment of the invention, the test can be carried out as a function of vehicle parameters and / or operating variables of the motor vehicle. Vehicle parameters of the motor vehicle describe the general state of the motor vehicle, for example:

• A vehicle weight,
• An air resistance coefficient and an end face,
• Rolling resistance coefficients of the vehicle tires,
• - Course parameter of the speed of the drive motor when synchronizing during a gear change, for example, a maximum positive and negative gradient or
• - A general condition of the engine brakes, such as light or stiff.

• – die Drehzahl des Antriebsmotors,
• – das Drehmoment des Antriebsmotors,
• – eine Stellung eines Leistungsanforderungselements, beispielsweise eines Fahrpedals,
• – ein Zustand der Motorbremsen, beispielsweise aktiv oder inaktiv,
• – der Ursprungsgang.

Operating variables describe the state of the motor vehicle at a specific time, for example when a gear change is requested. Company sizes are for example:

• The speed of the drive motor,
• The torque of the drive motor,
• A position of a power request element, for example an accelerator pedal,
• A state of engine braking, for example active or inactive,
• - the original course.

The Vehicle parameters and the operating variables can partly directly by means of detected further sensors, measured in special operating situations or determined by means of suitable calculation methods from measured quantities become.

In order to can the behavior of the motor vehicle, such as the course the vehicle speed or the speed of the drive motor during a Gear changes, especially for the time span in which the drive motor is not connected to the vehicle wheels is to be predetermined. Taking into account these sizes can the exam, whether a gear change with closed clutch is feasible, exactly. The danger that the test will be a wrong result supplies, is therefore low.

at the choice of whether a gear change with open or closed clutch is carried out, can be guaranteed be that the requested gear changes are feasible.

In Embodiment of the invention, the selection and / or the test at least in sub-operating areas depending on performed by the target gear of Schaltklauengetriebes.

Thus, the risk that the test whether a gear change with a closed clutch is feasible, provides incorrect results, FITS it's low.

For example is at an upshift, the speed of the drive motor and so that the speed of the transmission input shaft by means of the braking torque, which applies the drive motor, in the direction of synchronous speed delayed. The braking torque is built up by little or no fuel is injected. additionally The braking torque can be increased by the use of motor brakes. The synchronous speed results from the speed of the motor vehicle and the target gear under consideration from further translation, for example, a rear axle, in the drive train. This changes the synchronous speed with changing Vehicle speed. To achieve the synchronous speed, must Therefore, the gradient of the speed of the drive motor will be significantly larger as the gradient of the synchronous speed. The danger that this is not The case is, especially at a high vehicle weight and with a strong delay of the motor vehicle with gear, i. without drive torque, given. In an exam, whether the gear change with closed clutch is feasible, dependent on from the mentioned vehicle parameters and / or operating variables a determined from the vehicle mass deceleration of the motor vehicle with a maximum negative gradient of the speed of the drive motor be compared. Thus, an accurate prediction, whether the dependent on the target gear Synchronous speed can be achieved and thus the circuit with the clutch closed carried out can be, possible.

• – Neigung der Fahrbahn,
• – Beschaffenheit der Fahrbahn, beispielsweise befestigte Straße, Schotter oder Matsch,
• – Umgebungstemperatur,
• – geodätische Höhe oder
• – Umgebungsdruck.

In an embodiment of the invention, the selection and / or the test are carried out at least in partial operating areas as a function of variables which describe the environment of the motor vehicle. These sizes are for example:

• - slope of the road,
• - the condition of the road, for example paved roads, gravel or mud,
• - ambient temperature,
• - geodesic height or
• - ambient pressure.

These Sizes can be partial detected directly by other sensors, in special operating situations measured or determined by means of suitable calculation methods become. Some sizes, such as Slope of the roadway, can also from a known navigation system with digital road map to disposal be put.

In order to can the prediction of the behavior of the motor vehicle at a change of gear and thus made the above test very carefully become.

In Embodiment of the invention, the vehicle parameters are changeable. The vehicle parameters can in selected Operating areas of the motor vehicle and determined with stored parameters be compared. In the event of deviations, new parameter values can be calculated and stored, so a so-called adaptation are performed. The newly saved parameter values are then selected and the exam.

It can Parameters are adapted, which can change very quickly, such as for example, the vehicle weight.

Farther can Parameters are adapted, which are before or at a first commissioning can not be set exactly, such as gradient parameters the speed of the drive motor. The history parameters, for example the maximum gradients of speed are from drive motor too Drive motor different and can also about a longer one Change period. Therefore, must for safety reasons as starting values for the adaptation unfavorable Values are assumed, for example, only small possible gradients the speed of the drive motor. Thus, the test may erroneously deliver the result that a requested gear change does not match closed clutch feasible is, although this with the actual Vehicle parameters possible would. By approach the adaptation the stored values become more and more the actual values, so that More and more circuits are performed with a closed clutch can.

In order to becomes a particularly low-wear operation of the motor vehicle allows.

In Embodiment of the invention has the shift claw transmission over a central synchronizing device that can be controlled by the control device, by means of which a transmission input shaft can be braked. The central synchronization device is in contrast to usual synchronizer rings several courses assigned. The control device selects during upshifts with opened Clutch off, whether the central synchronizer driven and thus the transmission input shaft is braked or whether a Control is omitted. The central synchronizer can For example, be designed as a known transmission brake, which directly on the transmission input shaft or on a countershaft acts.

This ensures that the transmission input shaft at upshifts with the clutch open, even with greatly changing vehicle speed, the synchronous speed of the target gear safely and quickly achieved. This allows fast upshifts and ensures safe operation of the motor vehicle.

In Embodiment of the invention remains at the beginning of downshifts the clutch is closed and the controller controls an actuator to lay out the original course. Subsequently, the control device determines a Time since activation of the actuator and monitors whether the original gear is interpreted. If this is the case, then the gear change with closed clutch carried out. If the determined time since actuation of the actuator a Exceeds threshold, without the original gear has been designed, opens the controller The clutch and the gear change is performed with the clutch open.

Around to interpret a gear may be associated Switching elements, such as a sliding sleeve, no or only transmit a very low torque become. This can be achieved by the fact that the clutch open or, with the clutch engaged, the torque output the drive motor targeted changed becomes. If the motor vehicle is in train operation, this must be Torque can be reduced; in overrun torque increase is necessary. Changes at the time of the desired Exposing the vehicle speed, so must the drive motor against the imposed speed change the transmission output and input shaft the said state am Set the switching element of the original gear. This is only possible if the dynamics of the drive motor is greater than the dynamics of Motor vehicle. For example, a strong vehicle deceleration is at the same time requested downshift in this regard especially critical.

With The method described above can also be used in critical situations requested circuits are performed safely. Besides that is for one preferably huge Proportion of gear changes with closed clutch no exact knowledge the vehicle parameters, the operating variables or the environmental variables necessary. Thus, a low-wear and safe operation of the motor vehicle are ensured when the not mentioned sizes ascertainable or not yet determined.

The Motor vehicle can in a particularly advantageous manner as a commercial vehicle accomplished be. The Schaltklauengetriebe can advantageously via a Vorschaltgetriebe, such as a split group, and a secondary transmission, For example, a range group, have.

In Particularly advantageously, it can be provided that in the case of that once the faultiness of the signal of the transmission input shaft speed sensor is determined, then switched only with the clutch closed becomes. Thus, it is ensured that gear changes in knowledge of Transmission input shaft speed made. It is only then the control unit of the clutch reset if the transmission input shaft speed sensor is operational again.

under claim 5 is particularly advantageous in combination with claim 4.

Further Advantages of the invention will become apparent from the description and the drawings out. embodiments The invention are shown in simplified form in the drawing and explained in more detail in the following description. In the drawing show:

1 a drive train of a motor vehicle with an automated shifting claw transmission in a schematic representation,

2 a flow chart of a gear change,

3a . 3b in each case a diagram for the time representation of operating variables of the motor vehicle with an upshift of the shift doggear and

4 a flowchart of a downshift in a second embodiment.

• – ein Kurbelwellendrehzahlsensor 100 einer Kurbelwelle 13,
• – ein Temperatursensor 101, mittels welchem die Öl-/Wassertemperatur des Antriebsmotors 14 erfassbar ist und
• – ein OT-Sensor 102, mittels welchem der Obere Totpunkt des jeweiligen Kolbens für den Zündzeitpunkt ermittelbar ist.

According to 1 has a drive train 10 a motor vehicle, not shown, a drive motor 14 on which of a control device 16 is controlled. The control device 16 is with actuators, not shown, for example, for an exhaust flap, not shown, of the drive motor 14 , in signal connection. Thus, the control device 16 Manipulated variables to the actuators of the drive motor 14 send. In addition, the controller is available 16 in signal connection with only partially shown sensors. These sensors include, among others

• - A crankshaft speed sensor 100 a crankshaft 13 .
• - a temperature sensor 101 , by means of which the oil / water temperature of the drive motor 14 is detectable and
• - an OT sensor 102 , By means of which the top dead center of the respective piston for the ignition time can be determined.

The crankshaft speed sensor 100 is a Hall sensor or alternatively a magnetoresistive sensor attached to an increment wheel 103 very exactly the speed of the crankshaft 13 sensed. The speed at this crankshaft speed sensor 100 is programmatically detected by the variable S ₂ . The OT sensor 102 is a Hall sensor or alternatively a magnetoresistive sensor attached to an increment wheel 104 rather inaccurate the position of a camshaft 105 sensed. The difference in the accuracy of the measurement is due to the fact that the crankshaft 13 or their increment wheel 103 on a four-stroke engine, it rotates at twice the speed as the camshaft 105 or their increment wheel 104 , Is the position of the camshaft of the control device 105 determined over time, as results in the control unit 16 a camshaft speed or about a doubling of this camshaft speed, the speed of the crankshaft 13 ,

The crankshaft 13 is non-rotatably via a crankshaft flange not shown in detail with a primary half 106 a friction clutch 12 connected, which also includes the flywheel of the drive motor 14 forms. This primary half 106 is frictionally coupled with a secondary half 107 the friction clutch 12 ,

• – einem Stellglied 110 der Kupplung 12,
• – einem Getriebeeingangswellendrehzahlsensors 108, mit welchem die Drehzahl der Getriebeeingangswelle 11 erfassbar ist und
• – nicht dargestellten Sensoren der Kupplung 12 und des Schaltklauengetriebes 19.

The friction clutch 12 is axial between the crankshaft 13 and a transmission input shaft 11 an automated synchronous ring-free Schaltklauengetriebes 19 arranged. The coupling 12 and the shift dog transmission 19 are from a controller 49 driven. The control device 49 is in signal communication with

• - an actuator 110 the clutch 12 .
• A transmission input shaft speed sensor 108 , with which the speed of the transmission input shaft 11 is detectable and
• - Not shown sensors of the clutch 12 and the shift doggearing 19 ,

Thus, the control device 49 the coupling 12 open or close and change gear in shift gear transmission 19 carry out. One from the transmission input shaft speed sensor 108 Constantly determined value for the transmission input shaft speed is constantly updated under the variable S ₁ in the control unit 49 stored. By means of further sensors, not shown, operating variables are the temperature of the clutch 12 and the transmission oil of Schaltklauengetriebes 19 detectable. In addition, the controller is available 49 in signal communication with the controller 16 , whereby an exchange of data, for example, operating variables of the drive motor 14 or the shift doggear 19 , as well as a request for speed changes of the drive motor 14 which is then from the controller 16 are possible. In particular, the control unit 16 the speed of the crankshaft 13 to the controller 49 pass on. This speed of the crankshaft 13 is by means of the speed sensor 103 detected. If its signal is implausible or even absent, the crankshaft speed will be in an emergency program from the transmission input speed sensor 108 specified. The control device 49 is also equipped with a control unit 51 connected, by means of which a driver gear change the shift doggearing 19 can request. Alternatively, gear shifts from a source to a target gear may also be fully automated by the controller 49 to be triggered. The determination of the target gear is dependent inter alia on the speed of the motor vehicle and an operating level of an accelerator pedal by the driver.

• – die Getriebeeingangswelle 11,
• – eine mittlere Hauptwelle 400 und
• – die zweite Hauptwelle 29

angeordnet. Dabei ist die mittlere Hauptwelle 400 an ihrem einen vorderen axialen Ende in der Getriebeeingangswelle 11 und an ihrem hinteren axialen Ende in der zweiten Hauptwelle 29 gelagert.The shift claw transmission 19 is designed as a so-called two-group transmission. Rotationally connected to the transmission input shaft 11 is a primary gearbox in the form of a splitter group 17 arranged. The split group 17 downstream is a main gearbox 18 , Thus, in the shift dog transmission 19 axially consecutive

• - The transmission input shaft 11 .
• - a central main shaft 400 and
• - the second main shaft 29

arranged. Here is the middle main wave 400 at its one front axial end in the transmission input shaft 11 and at its rear axial end in the second main shaft 29 stored.

• – eine Festrad 20b, welches drehfest und koaxial am vorderen Ende der Vorgelegewelle 22 angeordnet ist und
• – ein Losrad 20c, welches drehbar und koaxial zur Getriebeeinganswelle 11 in der Ebene des Festrades 20b mit letzterem im verzahnten Eingriff angeordnet ist.

By means of the split group 17 can the transmission input shaft 11 over two different gear pairings 20a . 21a with a parallel to the transmission input shaft 11 arranged countershaft 22 be brought into operative connection. This includes the front gear stage 20a

• - a fixed bike 20b , which rotatably and coaxially at the front end of the countershaft 22 is arranged and
• - a loose wheel 20c which is rotatable and coaxial with the transmission input shaft 11 in the plane of the fixed wheel 20b is arranged with the latter in the toothed engagement.

• – ein Festrad 21b, welches drehfest und koaxial auf der Vorgelegewelle 22 hinter dem Festrad 20b angeordnet ist und
• – ein Festrad 21c, welches drehfest und koaxial zur mittleren Hauptwelle 400 in der Ebene des Festrades 21b mit letzterem im verzahnten Eingriff angeordnet ist.

The rear gear stage 21a includes, however

• - a fixed bike 21b , which rotatably and coaxially on the countershaft 22 behind the fixed wheel 20b is arranged and
• - a fixed bike 21c , which rotatably and coaxial with the central main shaft 400 in the plane of the fixed wheel 21b is arranged with the latter in the toothed engagement.

• – indem eine Schiebemuffe 41 aus einer Neutralstellung axial nach vorne geschoben wird, um eine drehfeste Verbindung zwischen der Getriebeeingangswelle 11 und dem Losrad 20c der vorderen Zahnradpaarung 20a oder
• – indem die Schiebemuffe 41 aus der Neutralstellung axial nach hinten geschoben wird, um eine drehfeste Verbindung zwischen der Getriebeeingangswelle 11 und der mittleren Hauptwelle 400 bzw. dem Losrad 21c herzustellen.

The two gear pairs 20a . 21a have a different translation. The Translation of the respective gear pairing 20a . 21a will be chosen,

• - by a sliding sleeve 41 is pushed axially forward from a neutral position to a rotationally fixed connection between the transmission input shaft 11 and the idler wheel 20c the front gear pairing 20a or
• - by the sliding sleeve 41 is pushed axially from the neutral position to the rear, to a rotationally fixed connection between the transmission input shaft 11 and the central main shaft 400 or the idler gear 21c manufacture.

On the countershaft 22 are also rotatable fixed wheels 23 . 24 . 25 for the 3rd, 2nd and 1st gear of the main gearbox 18 arranged. The fixed wheels 23 . 24 . 25 comb each with associated loose wheels 26 . 27 . 28 which is rotatable on the coaxial with the transmission input shaft 11 arranged second main shaft 29 are arranged. The idler wheel 26 can by means of a sliding sleeve 30 , the loose wheels 27 and 28 by means of a sliding sleeve 31 rotationally and positively with the second main shaft 29 get connected.

At the countershaft 22 is a synchronizer in the form of a transmission brake 52 arranged, which of the control device 49 is controllable. By means of the transmission brake 52 can the speed of the countershaft 22 and thus also the speed of the transmission input shaft 11 be specifically reduced.

The sliding sleeve 41 the split group 17 and the sliding sleeves 30 . 31 . 39 of the main gearbox 18 are each with shift rails 42 . 43 . 44 . 45 actuated. This can be a positive connection between associated switching elements with shift dogs and the second main shaft 29 be prepared or interrupted. The shift rails 42 . 43 . 44 . 45 can with an actuator in the form of an xy-actuator 48a . 48b , which of the control device 49 is actuated, be actuated. If no gear in Schaltklauengetriebe 19 is inserted, so no loose wheel form-fitting with the second main shaft 29 is connected, then there is the Schaltklauengetriebe 19 in a so-called neutral position.

From the second main shaft 29 becomes the converted torque and the speed of the drive motor 14 by means of a flanged drive shaft 32 to a axle drive 33 which, with balanced torque, the speed via a differential in equal or different proportions via two output shafts 34 . 35 to drive wheels 36 . 37 transfers.

When changing gear from an original gear to a target gear, the original gear must first be designed. Because the shift dog transmission 19 is designed as a transmission without synchronizer rings, at least in downshifts to insert the target gear can, the countershaft 22 and thus also the input shaft 11 by means of the drive motor 14 with the clutch closed 12 be set approximately to the synchronous speed of the target gear. The synchronous speed is reached when the idler gear of the target gear and the second main shaft 29 at least approximately the same speed. For upshifts with open clutch 12 can the countershaft 22 by means of the gearbox brake 52 braked and thus the input shaft 11 be synchronized.

The layout of the original gear can be done either with the clutch closed or open. Frequent opening and closing of the clutch 12 This leads to heavy wear and thus high costs for a replacement of the clutch and failure of the motor vehicle during the exchange. Therefore, the goal is to carry out the highest possible proportion of gear changes with the clutch closed.

• – ein fehlerhafter,
• – ein unplausibler oder
• – überhaupt kein

This is done by the controller 49 as shown in the flowchart in 2 shown after a switching request according to block 60 in the following block 200 a variable S is _{actively set} to the S ₁ , so that from this time the constantly updated transmission input shaft speed by means of the transmission input shaft speed sensor 108 is detected. In the following branch 61 checked, if no commissioning of the powertrain 10 is present and whether a period of time after a start of the drive motor 14 has expired. If the test is positive, then in the block 62 checked whether under the constantly updated variable S _active

• - a faulty,
• - an implausible or
• - absolutely no

Value is stored. If this verification of the signal of the transmission shaft speed sensor fails 108 positive, there is an error, so from the next block 201 the signal for the variable S _active the crankshaft speed sensor 100 is taken, with S _{2 is} stored under the variable S _active .

• – an einer weiteren Komponente des Antriebsstrangs 10 eine Fehlfunktion bzw.
• – an einem weiteren Sensor ein fehlerhaftes Signal

erkannt wurde. Dazu werden Informationen von anderen Steuerungseinrichtung, beispielsweise der Steuerungseinrichtung 16, oder von anderen Programmteilen eines Steuerprogramms der Steuerungseinrichtung 49, welche Funktionen von Komponenten überwachen, ausgewertet. Fällt die Prüfung negativ aus – es liegt also kein Fehler vor – so wird in der Verzweigung 63 geprüft, ob die Schaltung mit geschlossener Kupplung 12 durchgeführt werden kann. Dazu wird der Verlauf der Drehzahl der Getriebeeingangswelle 11 während der angeforderten Schaltung auf Grund der bekannten Fahrzeugparameter, der Betriebgrößen des Kraftfahrzeugs und der Umweltgrößen mittels an sich bekannten Bewegungsgleichungen vorausberechnet. Anschließend wird der vorausberechnete Verlauf mit den gespeicherten maximalen Gradienten der Drehzahl des Antriebsmotors 14 verglichen und festgestellt, ob zum einen ein Auslegen des Ursprungsgangs und zum anderen eine Synchronisation der Drehzahl der Getriebeeingangswelle 11 auf die Synchrondrehzahl des Zielgangs möglich ist. Fällt die Prüfung positiv aus, so wird in Block 64 die Schaltung bzw. der Gangwechsel bei geschlossener Kupplung 12 durchgeführt. Dazu wird mittels einer Änderung des abgegebenen Drehmoments des Antriebsmotors 14 durch die Steuerungseinrichtung 16 das übertragene Drehmoment an den Schaltelementen des Ursprungsgangs so weit reduziert, dass der Ursprungsgang ausgelegt werden kann. Anschließend findet die Synchronisation mittels des Antriebsmotors 14 statt. Sobald die unter S_aktiv ständig aktualisierte Drehzahl der Getriebeeingangswelle 11 bzw. der Kurbelwelle 14 zumindest in etwas die Synchrondrehzahl des Zielgangs erreicht hat, wird der Zielgang eingelegt. Anschließend wird an des Antriebsmotors 14 wieder das Drehmoment eingestellt, welches der Fahrzeugführer mittels eines nicht dargestellten Fahrpedals vorgibt. Damit ist in Block 65 die Schaltung abgeschlossen.On the other hand, the check falls in the branch 62 negative, so that the variable S _{actively has} a plausible value, the block becomes 201 skipped and it gets in the branch 202 checked if

• - on another component of the drive train 10 a malfunction or
• - At a further sensor a faulty signal

was detected. This will be information from its control device, for example the control device 16 , or other program parts of a control program of the control device 49 which monitor functions of components evaluated. If the test is negative - so there is no error - so is in the branch 63 checked if the circuit with the clutch closed 12 can be carried out. This is the course of the speed of the transmission input shaft 11 during the requested circuit on the basis of the known vehicle parameters, the operating variables of the motor vehicle and the environmental variables pre-calculated by means of known motion equations. Subsequently, the predicted course with the stored maximum gradient of the rotational speed of the drive motor 14 compared and determined whether on the one interpretation of the original gear and on the other a synchronization of the speed of the transmission input shaft 11 to the synchronous speed of the target gear is possible. If the test is positive, then in block 64 the shift or the gear change when the clutch is closed 12 carried out. This is done by means of a change of the output torque of the drive motor 14 by the control device 16 the torque transmitted to the switching elements of the original gear so far reduced that the original gear can be interpreted. Subsequently, the synchronization takes place by means of the drive motor 14 instead of. As soon as the S _actively updated under S speed of the transmission input shaft 11 or the crankshaft 14 At least in something has reached the synchronous speed of the target gear, the target gear is engaged. Subsequently, on the drive motor 14 set the torque again, which dictates the driver by means of an accelerator pedal, not shown. This is in block 65 the circuit is completed.

• –liegt also eine Erstinbetriebnahme vor oder eine Zeitschwelle nach Start des Antriebsmotors 14 ist noch nicht abgelaufen, oder
• – wurde bei einer Komponente des Antriebsstrangs 10 bzw. einem Sensor eine Fehlfunktion festgestellt oder
• – ist die Schaltung nicht mit geschlossener Kupplung 12 durchführbar,

so wird in Block 66 die Kupplung 12 durch Ansteuerung von der Steuerungseinrichtung 49 geöffnet. Anschließend wird in Verzweigung 67 geprüft, ob eine Hochschaltung ausgeführt werden soll. Ist dies der Fall so wird in Verzweigung 68 anhand von den in der Verzweigung 63 vorausberechneten Verläufen geprüft, ob die Getriebebremse 52 aktiviert, die Vorgelegewelle 22 und damit auch die Getriebeeingangswelle 11 aktiv abgebremst werden sollen. Fällt die Prüfung positiv aus, so wird in Block 69 die Schaltung in an sich bekannter Weise mit Aktivierung der Getriebebremse 52 durchgeführt. Dazu wird der Ursprungsgang ausgelegt, die Synchronisation mit Unterstützung durch die Getriebebremse 52 durchgeführt und anschließend der Zielgang eingelegt.If the exam falls in the branch 202 positive or in the branch 61 or 63 negative, ie it

• Is therefore a first commissioning before or a time threshold after the start of the drive motor 14 has not expired, or
• - was at a component of the powertrain 10 or a sensor detected a malfunction or
• - The circuit is not closed with clutch 12 feasible

so will be in block 66 the coupling 12 by activation of the control device 49 open. Subsequently it is branched 67 checked whether an upshift is to be executed. If so, it will branch out 68 based on those in the branch 63 precalculated curves checked whether the transmission brake 52 activated, the countershaft 22 and thus also the transmission input shaft 11 should be actively decelerated. If the test is positive, then in block 69 the circuit in a conventional manner with activation of the transmission brake 52 carried out. For this purpose, the original gear is designed, the synchronization with the help of the transmission brake 52 and then the target gear is inserted.

If the exam falls into branching 67 or 68 negative, so it should be a downshift or an upshift without activating the transmission brake 52 be executed, so will block 70 the circuit in a conventional manner without activating the transmission brake 52 executed.

After the blocks 69 or 70 So, if the target gear is engaged, in block 71 the coupling 12 closed again and on the drive motor 14 set again the torque specified by the driver. This is also in block 65 the circuit is completed.

The process can also do without the branches 61 and or 202 be performed.

In the 3a and 3b is the time course of operating variables of the motor vehicle at an upshift of Schaltklauengetriebes 19 from a source to a target gear. By means of these courses, the feasibility of upshifts with closed clutch is explained in more detail.

In the 3a and 3b are on abscissa 80a . 80b the time, on ordinates 81a . 81b a speed or a clutch status applied.

In a phase a1 in 3a the original gear is still inserted. The drive motor 14 gives off a constant torque and the motor vehicle accelerates, so that by means of line 82a shown speed of the drive motor 14 increases. At the time 83a the driver asks by means of the operating unit 51 an upshift. In phase b1 the drive motor decreases 14 the output torque (not shown) so that the original gear can be designed. This causes a fluctuation of the rotational speed of the drive motor 14 in phase b1. At the end of phase b1, at the time 84a is designed the original gear, the shift claw transmission 19 is thus in a neutral position. In phase c1, the speed of the drive motor decreases 14 due to the engine braking effect.

The synchronous speed of the target gear is as described proportional to the speed of the motor vehicle. The lines 85a and 86a show the course of the synchronous speed in two different cases. In the first by line 85a In the case shown, the synchronous speed decreases only slowly. This may be due, for example, that the road is slightly sloping. At the time 87a reaches the speed of the drive motor 14 the synchronous speed, which is represented by the lines 82a and 85a to meet. Thus, the target gear can be engaged and adjusted by the driver requested torque. The circuit is thus completed and the motor vehicle accelerates again, the speed of the drive motor 14 rises again in phase d1. The coupling 12 remains closed during the entire shift, as by line 88a in condition 1 you can see.

The second case is by line 86a shown. In this second case, the synchronous speed drops very sharply. This may be due, for example, to the fact that the road surface is rising and / or the vehicle is heavily loaded and / or the road surface is very soft. The synchronous speed drops faster than the speed of the drive motor 14 , Thus, the speed of the drive motor 14 can not reach the synchronous speed, the target gear can not be engaged. Thus, the circuit can not be closed with the clutch 12 be performed.

When considering whether the circuit with the clutch closed 12 can be performed - branching 63 in 2 -, These curves of the speeds are calculated in advance and checked whether the speed of the drive motor 14 the synchronous speed reached or not. If this is not the case, the circuit can not with the clutch closed 12 be performed.

In 3b is again the second case shown, with the difference that in the illustrated gear change, the clutch 12 is opened. In phase a2 is the clutch 12 closed, what by line 88b in condition 1 is shown. With the switching request at the time 83b the course of the speeds is calculated in advance and found that the circuit only with the clutch open 12 can be executed. As a result, the clutch becomes 12 immediately opened so that it is in state 0. In phase b2, the original gear is laid out and in phase c2 the line is selected 82b shown speed of the drive motor 14 by means of the gearbox brake 52 braked. This achieved at the time 87b the speed of the drive motor 14 the synchronous speed, the target gear can be engaged and the clutch 12 getting closed. The circuit is thus completed and the motor vehicle accelerates again in phase d2. The circuit can thus be carried out with the clutch open.

In 4 is a flowchart of a downshift according to a second embodiment shown. After a switch-back request according to block 90 will be in block 91 the output torque of the drive motor 14 as in a closed-clutch circuit 12 changed, so that the original course would have to be interpretable. In the following block 92 becomes the xy-controller 48a . 48b controlled to interpret the original course. Subsequently, in the block 93 checked whether the original gear was designed. If so, it will be in the branch 94 queried whether that from the transmission input shaft speed sensor 108 incoming signal, which is stored under the variable S ₁ constantly updated, is correct or plausible or even present.

If this is the case, then take as per block 300 the variable S _actively in a constantly updated manner, the value of the variable S ₁ , whose value by means of the signal of the transmission input shaft speed sensor 108 is formed.

If this is not the case - that is, there is an error - so takes block 301 the variable S _actively in a constantly updated manner, the value of the variable S ₂ , whose value by means of the signal of the crankshaft speed sensor 100 is formed.

Following in the block 300 respectively. 301 performed selection of the speed sensor is in the block 302 the closed-clutch circuit is performed in response to the variable Sakti _v . After performing the return formwork, the process is in the block 95 completed. If the exam in block 93 negative, the original gear was not interpreted, is in the block 96 Checked whether the time since activation of the xy-actuator 48a . 48b has crossed a threshold. If this is not the case, then the block 93 repeated. Is the threshold in block 96 is exceeded, so in block 97 the clutch is open, in block 98 the circuit is performed with the clutch open and in block 99 the clutch is closed again. Thus, the circuit is also in the block 95 completed.

The mentioned time threshold in the block 96 may be of vehicle parameters of the motor vehicle, such as the vehicle weight, and / or operating variables of the motor vehicle, for example, speed of the drive motor 14 , and / or of variables which describe the environment of the motor vehicle, for example the inclination of the roadway.

This in 4 The illustrated method is performed when the gear change is to be performed with the clutch closed.

The above-described occurrence of an error in the signal of the transmission input shaft speed sensor 108 can be done, for example be determined that when the clutch is closed 12 the signal of the crankshaft speed sensor 100 with the signal of the transmission input shaft speed sensor 108 is compared. If the two signals differ from one another via a tolerance value, then either the crankshaft speed sensor is located 100 or at the transmission input shaft speed sensor 108 an error. By comparing the respective signal, for example with the signal of the TDC sensor over time, it is possible to determine whether the transmission input shaft speed sensor 108 or the crankshaft speed sensor 100 provides a faulty signal.

The Occurrence of an error is in the case of complete failure of one Sensor can also be determined without comparison with another sensor.

The said threshold may be of vehicle parameters of the motor vehicle and / or operating variables of the Motor vehicle and / or sizes, which describe the environment of the motor vehicle, be dependent.

• – Antriebsmotormoment
• – Antriebsmotordrehzahl
• - Getriebegang, d.h. Übersetzungsverhältnis im Getriebe

umsetzt.Instead of the two control devices 16 . 49 For the drive motor and the switching operations, a common control device can be provided. Instead of a common control unit, which replaces the two latter control means, but also a higher-level control device can be provided, which coordinates the control means of the drive motor and the Schaltklauengetriebes. Such a control unit can be designed as a powertrain manager, which determines the power requirement of the driver in an optimization

• - Drive motor torque
• - Drive motor speed
• - Gear, ie gear ratio in the transmission

implements.

• – der am Getriebeeingangswellendrehzahlsensor 108b sensierten Drehzahl und
• – der bekannten Übersetzungsverhältnisse der beiden Zahnradpaarungen 20a, 21a

die Getriebeeingangswellendrehzahl.In 1 In addition, an alternative embodiment of the invention is shown. It is instead of the transmission input shaft speed sensor 108 a cross-hatched transmission input shaft speed sensor 108b provided, which the speed of the transmission input shaft 11 not directly on the transmission input shaft 11 decreases. Instead, the speed of the central main shaft 400 from the transmission input shaft speed sensor 108b sensed. This speed is via a data transmission line not shown to the controller 49 transfer. The control unit 49 are the current positions of the xy-writer 48a . 48b known, so that also the current positions of the sliding sleeves 41 . 30 . 31 . 39 the control unit 49 are known. Represents the sliding sleeve 41 a non-rotatable connection between the transmission input shaft 11 and the middle intermediate shaft 400 her, so is the at the transmission input shaft speed sensor 108b Sensed speed equal to the transmission input shaft speed. Represents the sliding sleeve 41 however, a non-rotatable connection between the Getriebeeinganswelle 11 and the idler wheel 20c the gear pairing 20a ago, so determines the controller 49 based

• - The at the transmission input shaft speed sensor 108b sensed speed and
• - The known ratios of the two gear pairs 20a . 21a

the transmission input shaft speed.

• – ein fehlerhafter
• – ein unplausibler oder
• – überhaupt kein

In a further alternative embodiment of the method for controlling a switching operation are from the time from

• - a faulty one
• - an implausible or
• - absolutely no

Value from the transmission input shaft speed sensor 108 respectively. 108b is delivered, each gear change performed with the clutch closed. Various alternatives are possible when this suppression of gear changes with open clutch 12 is ended or reset. In an alternative, this suppression of gear changes with the clutch open 12 then reset when the drive motor 14 turned off and then started again. In another alternative, this suppression of gear changes with the clutch open 12 be reset exclusively manually via a bidirectional diagnostic and / or application device. A specialist from the workshop closes this diagnostic and / or application device to a diagnostic connector of the control unit 49 and gets displayed in the display of the diagnostic device, that of the transmission input shaft speed sensor 108 respectively. 108b delivered value is faulty. Following the error, for example, by cleaning a plug contact or change the transmission input shaft speed sensor 108 respectively. 108b to be repaired. Subsequently, the fault memory is emptied by means of the bidirectional diagnostic and / or application device, so that the suppression of gear changes with the clutch open 12 finished or reset.

Instead of engaging the two Schaltklauenhälften the Schaltklauengetriebes with equal speed, in the invention, a switching method can be applied, in which the Schaltklauenhälften be engaged at a speed difference. Such a switching method can be carried out particularly well with a specific switching jaw geometry and is for example in the DE 197 17 042 C2 described. The latter patent is herewith incorporated by reference as in this application apply.

Instead of a transmission brake to brake the countershaft are also Other devices or control methods conceivable. Especially drive motor side measures, like a constant throttle or an exhaust throttle can be at a Drive train according to the invention Find application.

at the described embodiments is they are only exemplary embodiments. A combination of described features for different embodiments is also possible. Further, in particular not described features of the invention belonging Device parts are the geometries shown in the drawings to remove the device parts.

Claims (6)

Drive train with a drive shaft ( 13 ) by means of an automated coupling ( 12 ) with a transmission input shaft ( 11 ) of an automated shift operating gear ( 19 ) can be coupled, wherein switching operations with the clutch engaged in dependence on a transmission input shaft speed representing value (S ₁ ) are executable by a transmission-side sensor ( 108 ) can be determined, wherein furthermore a drive-side sensor ( 100 or 102 ) is provided which determines a drive shaft speed representing value (S ₂ ), characterized in that in case of error of the signal of the one sensor ( 108 respectively. 100 / 102 ) the other sensor ( 100 / 102 respectively. 108 ) forms a substitute signal. Drive train according to claim 1, characterized in that in case of failure of the transmission-side sensor ( 108 ) the value of the drive-side sensor ( 100 or 102 ) provides a substitute signal for the transmission input shaft speed representing value (S ₂ ), so that switching operations in dependence on the replacement signal of the drive-side sensor ( 100 or 102 ) are feasible. Drive train according to claim 1, characterized in that the drive-side sensor is a crankshaft speed sensor ( 100 ) and in the event of an error, the value of the transmission-side sensor ( 108 ) provides a substitute signal for the crankshaft speed representing value (S ₂ ), so that a drive motor control ( 16 ) the speed and / or the torque of the drive shaft ( 13 ) in response to the substitute signal of the transmission-side sensor ( 108 ) controls. Method for controlling a switching operation of an automated shift operating gear ( 19 ), in which a drive torque of a drive shaft ( 13 ) via an automated clutch ( 12 ), wherein switching operations with the clutch ( 12 ) as a function of a value (S ₁ ) representing the transmission input rotational speed, characterized in that, if the value (S ₁ ) is erroneous, a further value (S ₂ ) representing a drive shaft speed is substituted. A method according to claim 4, characterized in that an error of the value by comparing the two values (S ₁ and S ₂ ) is determined. Method according to one of the claims 4 or 5, characterized in that at faulty value (S ₁ ) switching operations exclusively with a closed clutch ( 12 ), until a fault memory of a control unit ( 49 respectively. 16 ) set error is reset.