DE10223465A1 - Clutch engagement point setting method uses electronic control of clutch actuator for ensuring torque delivered by engine corresponds to given engagement torque - Google Patents

Abstract

The clutch engagement point setting method has the clutch actuator controlled via an electronic control device (14), so that the torque delivered by the engine (2) to the drive transmission corresponds to a given engagement torque, with monitored engine operating parameters used for calculation of the overall engine torque, from which the torque required by the auxilaries driven by the engine is subtracted. An Independent claim for a control device for controlling a clutch in an automobile drive transmission is also included.

Description

The invention relates to methods for setting the gripping point one of one Clutch actuator actuated clutch and further relates to a control device to control a clutch.

Automated clutches are found not only because of the com achieved with them profit, but also because of possible consumption savings vehicles are increasingly used.

Fig. 5 is an exemplary block diagram showing a powertrain of a vehicle equipped with an automated clutch motor vehicle. The drive train contains an internal combustion engine 2 , a clutch 4 and a transmission 6 , from which a drive shaft 8 leads to drive wheels, not shown. The transmission 6 is, for example, an automated manual transmission or a conical disk transmission with a continuously variable transmission ratio. For actuation or for switching the transmission 6 , an actuating device 9 is used , which can be controlled from a selector 10 by means of a selector lever 12 via a control device 14 in a manner known per se. It is understood that the Wahlin direction can also be designed differently, for example as a classic shift lever (H-link) or as a lever with tip positions for up and down switching. The clutch 4 is, for example, a friction disk clutch of a type known per se with an actuating device 16 which is designed hydraulically, electrically, electrohydraulically or in some other known manner.

Sensors contained in the drive train, such as a pressure sensor 18 for detecting the intake pressure of the engine 2 , a speed sensor 20 for detecting the speed n _{M of} the crankshaft of the engine, a sensor 22 for detecting the position α of an accelerator pedal 24 , and a sensor 28 for detecting the Position of the selector lever 12 and another speed sensor 28 for detecting the speed of the drive shaft 2 are connected to the inputs of the control unit 14 .

In the control unit 14 , which contains a microprocessor with associated memories 29 in a manner known per se, maps and programs are stored with which actuators, such as a load actuator 30 for adjusting the load of the motor 2 , the actuating device 16 of the clutch 4 and the actuating device 9 of Ge gear 6 and other consumers 31 , directly or indirectly driven by the engine, such as a generator, a pump or a heating element, etc., are controlled. The individual actuators can be constructed in such a way that their position is directly known in the control unit 14 , for example as stepper motors, or additional position transmitters, such as a position transmitter 32 for detecting a parameter relevant to the position s _{K of} the clutch, can be provided.

A further control unit 34 is connected to the control unit 14 via a data bus 33 , which, for example, controls the vehicle brakes 35 , as is known from anti-lock systems or driving stability systems. The hardware and software distribution between devices 14 and 34 is adapted to the respective conditions.

The structure and function of the device described are known per se and are therefore not explained in detail. Depending on the driving request communicated via the accelerator pedal 24 and the request for a driving program or driving direction communicated via the selector lever 12 , the load actuator 30 , the actuating device 16 and the actuating device 9 are actuated in a mutually coordinated manner depending on signals supplied by the sensors , so that there is comfortable and / or economical driving.

For the actuation of the clutch 4, for example, a characteristic curve is stored in a memory of the control device 14 , which defines a desired position of the clutch 4 set by the actuating device 16 as a function of the torque to be transmitted by the clutch 4 . For reasons of control quality, the wear of the coupling and the energy consumption of the actuating device, the transferable coupling torque should only be as large as is absolutely necessary. The required torque to be transmitted results from the driver's request or the position of the accelerator pedal 24 and, for example, the load of the internal combustion engine 2 detected by the sensor 18 and possibly further operating parameters such as the speed of the engine 2 etc.

The characteristic stored in the control unit 14 , which indicates the desired path of a movement of the actuating device 16 actuator of the clutch as a function of the calculated torque to be transmitted, has a decisive influence on a comfortable starting and a comfortable handling of the switching operation. The characteristic changes briefly, for example as a result of temperature changes, and long-term over the course of the life of the clutch, for example as a result of wear. It is therefore constantly updated or re-enacted according to a variety of strategies in the event of predetermined operating conditions.

Fig. 6 shows an example in detail of an actuating device 16.

In a master cylinder 36 filled with hydraulic fluid works a piston 38 , the sen shaft 40 has an external toothing which meshes with an internal toothing of a gear 41 , which in turn engages with the external toothing of a Rit 42 of an electric motor 43 , which is controlled by the control unit 14 ( Fig. 4) is controlled. The electric motor can be of any suitable type and is controlled, for example, by means of a PWM signal. The electric motor is advantageously a stepping motor. The master cylinder 36 has a sniffer bore 44 which is connected via a line 45 to an expansion tank (not shown). A line 48 leads from the pressure chamber 46 of the cylinder, which leads to a slave cylinder 50 in which a piston 52 works, which is connected via its piston rod, for example, to the release lever 54 of the clutch which forms an actuator. The position A, which is generally referred to as the sniffing position, is the position when it is passed over by the piston 38 according to FIG. 4 to the right in the pressure chamber 46, pressure for clutch actuation builds up.

For determining the position, an incremental position transmitter 32 , known in its construction, is provided on the gear 41 , for example, which counts the number of teeth on the gear 41 moving in front of it and emits corresponding pulses to the control unit 14 . The number of these pulses is a direct measure of the displacement of the master piston 38 or, if the master piston 38 according to FIG. 9 is to the right of the sniffing position A, the movement of the release lever 54 .

In a so-called sniffing process, the master piston 38 , in which a non-illustrated check valve is integrated before, so that if the overpressure on the left side of the piston 38 opens, it moves to the left over the sniffing position A, which is the hydraulic path located between the pistons 38 and 52 is connected to line 45 and is depressurized. In this depressurized state of the hydraulic path, the release lever 54 takes its position corresponding to the fully closed or closed position of the clutch. When the master cylinder 38 is moved to the right by the electric motor 42 , actuation of the release lever 54 begins at the moment when the master piston 38 passes over the sniffing position A. This position of the Geberkol bens 38 can be detected in various ways, wherein the respective count of the position sensor 32 as chert vomit closed position in the control unit fourteenth

In addition to the closed position of the clutch, there is a precise knowledge of the gripper important point of the clutch, this is the position in which the clutch is on predetermined, small torque of 4 Nm, for example. The ge Precise knowledge of the gripping point is important because it when starting and plays a crucial role in shifting. If the clutch over the Is also completely separated. Will the clutch A gear change without massive comfort is not activated up to the gripping point influence or even danger of the transmission is not possible and the driving stuff creeps too strong.

The gripping point is normally set such that in certain operating states of the drive train, for example when the vehicle is stationary and the brake is applied and the gear is engaged, the clutch is fully opened and then slowly closed, the engine torque being measured. If, during the slow closing of the clutch, the engine torque, which is given, for example, by an actuator of the idle control in a particularly simple manner in an engine with idle control, reaches the predetermined value, the position transmitter 32 is read out and its value is stored as the gripping point of the clutch. The gripping point can thus be approached quickly and serve as an orientation value for carrying out a starting process or a switching process.

In practice, the gripping point is determined and set numerous problems; for example, that transmitted by the clutch Torque cannot be easily measured since the engine is additional Drives auxiliary units that u. U. during a gripping point setting or switch off or otherwise change their power requirements.

The invention has for its object problems with which the determination and adjustment of the gripping point is connected to solve.  

A first solution to this problem is the method according to the An spell 1 solved. This procedure ensures that the engine mo ment can be detected in a simple manner via operating parameters of the engine can and from this, taking into account that of the auxiliary units torque taken, the clutch torque is derived so that it does not is adulterated by the auxiliary units.

With the features of claim 2 it is achieved that of the subsidiary gregaten recorded moment at the. Adjustment of the gripping point can be taken into account.

With the features of claim 3 it is achieved that the switching on or off ten of an auxiliary unit during the execution of a gripping point cycle is recognized.

The method according to claim 4 is one compared to claim 3 modified implementation form, with the adulteration at the Gripping point setting can be recognized by switching on or off ancillary equipment or other consumers.

With the features of claims 5 and 6 is also achieved that a Gripping point setting is not falsified by auxiliary units.

With the features of claims 7 and 8 one from a vehicle ongoing danger when setting the gripping point, for example there by the fact that the vehicle starts moving unintentionally sen.  

The claim 9 characterizes a method that the emergency adaptation of Gripping point is advantageously applicable.

The claim 10 is directed to a method in which the gripping point without Torque measurement can be set. The clutch is up to a stored gripping point, which can be a piloted gripping point or is a grip point determined in a previous update cycle, ge opens. Then a gear is engaged and an operating parameter is measured, which is normally influenced by the engagement of a gear. This Be drive parameters can be a support motor applied by the motor to its bearing ment, a torque acting on the output shaft or also a Force with which a shift lever is actuated, with the engagement of a gear connected noise, etc. The operating parameters should be correct Gripping point assume a setpoint. Deviates the measured value of the operation parameters from the setpoint, the gripping point is in the direction of a ver reduction of the deviation changed.

According to claim 11, the measured operating parameter is advantageously the force required to engage a gear, for example immediately is measurable by operating parameters of the actuator.

The claim 12 characterizes the basic structure of a Steuerein direction by which one or more of the methods of the invention are feasible.

The invention is explained in more detail below on the basis of exemplary embodiments, a drive train in which the invention can be used being constructed, for example, as illustrated with reference to FIGS . 1 and 2 already explained.

They represent:  

Fig. 1 shows a detail from FIG. 5,

Fig. 2 is a curve giving the torque transmitted by the clutch in response to an actuating path of a clutch actuator on,

Fig. 3 is a graph indicating a required for inserting a driving force transfer function of the deviation of the engagement point from a desired position,

Fig. 4 is a flowchart for explaining the driving Ver invention,

Fig. 5 is a schematic representation of a known drive train of a motor vehicle with an associated control unit and

Fig. 6 shows a clutch actuation device with a hydraulic path. The following description relates in each case to clutches which are included in a drive train according to FIG. 5 for example and which are actuated by a motor, preferably an electric motor, with the interposition of different transmission devices.

The structure shown in FIG. 5 is only an example and can be supplemented by further components, modified by omitting components or have a different construction, it being essential that the parameters described below are each detected by sensors, so that they are available in the control unit in order to carry out the individual exemplary described methods using stored programs and setpoints.

The torque generated by the engine 2 in FIG. 5 can be calculated by measuring under different operating parameters of the engine, for example intake manifold pressure and engine speed, and can be made available to a data network of the vehicle, for example the control unit 14 . In order to know the torque transmitted by the clutch 4 when the gripping point is set or updated, the drive torque of the running consumers, such as air conditioning compressor, motor fan, power steering, etc., must be deducted from the engine torque. The control unit 14 detects the operation of these consumers, for example their speed, power output, etc., and calculates, for example, on the basis of maps or characteristic curves stored in the control unit 14 , the torque recorded by the consumers. In this way, it is possible to carry out a gripping point adaptation without having to measure the torque transmitted by the clutch 4 directly, for example by measuring the clutch output torque on the output shaft 8 and, taking into account losses caused by the transmission 6 , is available for the gripping point setting ,

Another way to consider the operation of consumers without knowing their power consumption in detail, is that of Engine generated torque immediately before a gripping point determination cycle capture and during a gripping point cycle the immediately determined Subtract engine torque from the current engine torque. Through these differences The mo. taken up by additional consumers must elements, provided they do not change during the gripping point determination, cannot be determined.

So that it can be ruled out that the power consumption of auxiliary units driven by the engine changes during touch point determination or setting, it is advantageous to store a program in control unit 14 which switches an on or off or a change in when a touch point determination cycle is activated Power consumption of other consumers or ancillary units prevented.

If this is not possible, for example, switching on or off a Radiator fan of the engine should not or can not be stopped, it is important It is necessary to recognize whether the radiator fan or another consumer is choosing switched on or off during a gripping point setting cycle or its Leis has suddenly changed. This is possible because the Mo Torque is determined at the beginning of a gripping point cycle, the clutch ac gate is then operated to perform a gripping point cycle such that the engine torque is increased by the gripping torque and the clutch actuator then in its initial position is moved back and the engine torque be again is true. If the engine torque redetermined from the beginning of a gripping point cycle detected engine torque, this indicates that Switching a consumer on or off during the gripping point cycle, see above that the gripping point cycle is assessed as faulty. It goes without saying that the clutch actuator in as quickly as possible after reaching the gripping torque its starting position should be moved back, so largely out It can be concluded that a consumer is exactly within time Room switches on and off or on and off by the clutch actuator is operated.

Advantageously, the above-mentioned process can be developed further that in addition to the engine torque, the engine speed is determined. On engine regulated in terms of its idle speed responds to torque ment changes initially with certain idle changes within of a typical regular time. If the clutch actuator is within this is typically operated in such a way that the clutch from the gripping point is brought into the fully open position, it works through the rotation Torque change caused by speed change after, so that the engine  not yet again with its initial speed, but with increased speed running. If, on the other hand, there is a gap between the fully open position tion of the clutch and reaching the gripping point a consumer has switched, the engine torque changes between the gripping position of the Clutch and the fully open position of the clutch relatively less, so that the engine speed reacts less strongly to the torque change and the determined speed change compared to the speed when gripping point is lower. Accordingly, by comparing the measured rotation Number change with one in the control unit for the period within which the Clutch is brought from the gripping position to the fully open position, typi speed change can be decided whether a consumer is in the critical period of gripping point determination or setting added or removed has switched or has changed in its power consumption.

An example of a consumer with a very high power consumption are electrical auxiliary heaters. Particularly in vehicles with modern diesel engines, the heating power that can be removed from the cooling water for the vehicle interior is not sufficient in certain operating states. The water used for heating such vehicles is additionally heated with electrical elements, the electrical elements, depending on their switching state, absorbing significantly different electrical power that must be applied by the alternator, so that the engine torque changes when the switching state of the electrical elements changes changes strongly. Is advantageous since here if the control device 14 certain electrical loads whose switching state change is associated with great changes in torque, during a gripping point cycle controlled such, their switching state that does not change.

Another way to falsify a gripping point Avoiding consumers consists in switching certain switches  stands of auxiliary units and / or consumers to carry out a Lock gripping point cycle.

It is understood that for the transmission of information via the switch state of individual consumers on the control unit all possibilities modern Data processing is available, for example information about averaging via a CAN bus, where a bit has the meaning ha ben, electric auxiliary heating on or off. The use of a individual bits has the advantage that it can be sent within a status byte that can. The bit changes either at each level of a step-by-step switchable electric heating its value or is switched on or off set and back after a defined time of, for example, one second set. When working with information processing via a bus system , this has the advantage that a wide variety of control units is easier Can communicate with each other in such a way that, for example, a bit can be sent that means "no consumers switch on "or" do not change the switching state "or" no gripping perform point cycle ".

A gripping point determination or a gripping point cycle is usually carried out at ste vehicle and operated service and / or parking brake leads. The driver is crawled when a gear is engaged in a standing position function forced to apply the brake to creep the vehicle to avoid. When the handbrake is applied, there is none for safety reasons Gripping point determination with an adjustment of the coupling in the direction of closing the clutch instead, but only in the direction of opening.

In order that the aforementioned restriction does not exist, it is advantageous if, for example in the arrangement according to FIG. 5, the control unit 14 informs the control unit 34 via the data bus 33 when performing a gripping point cycle that the vehicle brake 35 is actuated with a predetermined minimum force, so that the vehicle is braked with a minimum braking torque that is higher than the clutch torque applied. The driver generally feels nothing of this increase in braking torque. The gripping point determination or setting thereby becomes uncritical; it can even take place while the driver has already completed the braking operation by himself. It can be ensured that no braking torque is applied when the clutch is fully opened. The grip point can be determined without the vehicle crawling. Safety-critical states are switched off.

Another way to prevent a vehicle from grabbing unpredictably sets the point in motion consists of, during a Gripping cycle the pressure that prevails in a hydraulic system or the Force with which the brakes are actuated, and an actuation of the Clutch actuator in the closing direction of the clutch during a gripping cycle or to prevent an entire gripping cycle if the grasped by the Brake pressure or the detected braking force known braking effect or that Braking torque is below a predetermined threshold.

In practice, cases cannot be ruled out in which, as a result of, for example, strong temperature changes in the hydraulic volume of FIG. 6 or other errors, for example errors in the position transmitter 32, a gripping point is inadvertently approached at which an undesirably high creeping torque or engine torque is present, which leads to dangerous conditions can lead. In this case, it is advantageous to carry out an immediate emergency adaptation of the gripping point by adjusting the gripping point by a predetermined amount, which may depend on the size of the impermissible creeping torque, in the direction of increasing opening of the clutch. For example, the gripping point can be immediately adjusted by 0.5 mm when a maximum creep torque is achieved in the event of an error. The size of the emergency adaptation can also depend on whether the gripping point is approached with the handbrake pulled and the footbrake not actuated, whether the engine speed drops, etc. It goes without saying that after such an emergency adaptation, the values for the clutch adjustment stored in the control unit 14 , in particular also in particular the stored value of the closed position of the clutch should be updated as quickly as possible, for example by performing a sniffing cycle, as explained at the beginning.

Another modified method for gripping points is determined below lung or setting explained:

Fig. 1 shows a section of the already described Fig. 5, wherein the actuating device 9 for the transmission 6 , which is an automated manual transmission in the example shown, a selector actuator 9 a for a selection process and an actuator 9 b for a switching operation. In addition, a further position transmitter 34 is provided in Fig. 1, which indicates the position of the switching actuator 9 b,

Fig. 2 shows a characteristic that the transmittable by the clutch 4 torque M as a function of a regulating distance s is an actuator of the clutch, as one example actuated by the actuator 16 of the clutch release lever. With travel path 0, the clutch is completely closed. When the travel path GP, the clutch is in its gripping position or its gripping point, in which it can transmit a predetermined, relatively small torque; If the adjustment is made beyond GP, the clutch opens fully and can no longer transmit torque. In the control unit 14 ( FIG. 5), when the transmission is functioning properly, the value of the position transmitter 32 , which it indicates when the clutch is in the correct gripping point position, is stored.

Fig. 3 shows the dependence of a force K on a deviation ΔGP of the actual gripping point from the correct gripping point. In the case of the deviation 0, the force K has a previously measured, relatively small target value K _S , which is stored in the control unit 14 . The force K can be measured by moving the switching actuator 9 b, for example at a constant speed, and measuring the power consumed in the process. The power can then be converted directly into the force. It is understood that the force can also be determined from other operating parameters of the switch actuator 9 b or by a force measuring device arranged in the power transmission between the actuator 9 b and the switching element of the transmission 6 .

The method according to the invention takes advantage of the dependency of the force K on the deviation of an instantaneous gripping point from a perfect gripping point, for example by the method described with reference to FIG. 4:
In a step 40 it is checked whether the vehicle is stationary, a vehicle brake is actuated (this can be done manually or controlled from the control unit 14 ) and the transmission is in a neutral gear. If all conditions are fulfilled, a gripping point adaptation is started in step 42 , whereupon in step 44 the clutch 4 is adjusted by the actuating device 16 to such an extent that it is in a gripping position stored in the control unit 14 or in the currently stored gripping point.

In step 46 , a shift gear of the transmission 6 is engaged by the shift actuator 9 b and the force required for this is determined by appropriate evaluation of operating parameters of the shift actuator 34 .

In step 48 it is determined whether the force K determined in step 46 is greater than a target force K _S stored in the control device 14 . If this is the case, in step 50 the gripping point stored in the control unit 14 is pushed in the direction of a reduction in the force, ie in the direction of increasing opening of the clutch. The shift can be carried out incrementally by a predetermined amount or according to a stored characteristic curve which assigns different deviations to different shifts.

If criterion 48 is not met, it can be checked in a further step, not shown, whether the measured force is significantly smaller than a target force, which indicates that the clutch is opening too far, whereupon the stored gripping point in the direction of a smaller opening of the clutch moved who can.

The described method can be modified in many ways; at for example, the method can also be used in vehicles with manual transmission and automated clutch can be performed by the gear lever of Ge drive is pushed by hand into a gear and the required Force is measured. The stored gripping point does not have to be indicated directly drive, but a point can be approached, for example se to a slightly larger actuating force than the target force at the gripping point leads so that the force can be measured more correctly. This deviation is in the stored values are taken into account.

The claims submitted with the application are drafted strikes without prejudice for obtaining further patent protection. The An notifier reserves the right to add more, so far only in the description and / or To claim drawings disclosed combination of features.

Relationships used in subclaims point to further training the subject of the main claim by the features of the respective towards subclaim; they are not considered a waiver of achieving one independent, objective protection for the combination of features to understand related subclaims.  

Since the subjects of the subclaims with regard to the prior art reserves the right to make its own independent inventions on the priority date Applicant before becoming the subject of independent claims or part to make statements of compliance. You can also continue to invent independently containing one of the subjects of the preceding subclaims Chen independent design.

The exemplary embodiments are not to be understood as a limitation of the invention hen. Rather, there are numerous variations within the scope of the present disclosure Rations and modifications possible, especially such variants, elements and combinations and / or materials, for example by combination or modification of individual in connection with that in the general Be writing and embodiments and the claims described and in the features, elements or process contained in the drawings steps can be taken by the person skilled in the art with regard to the solution of the task are and through combinable features to a new item or lead to new process steps or process step sequences, also insofar as they Manufacturing, testing and working procedures concern.

Claims (12)

1. Procedure for setting the gripping point of a clutch actuator actuated clutch, which clutch actuator is controlled by an electronic Control device is controlled, the control device Clutch actuator controls such that one of an engine uses the clutch torque transmitted to a powertrain a predetermined gripper torque corresponds to the procedure with which the engine operating parameters from which the total engine torque is determined, the Operation of ancillary units driven by the engine is detected need a total of an accessory drive torque, and that of the Clutch transmitted clutch torque is formed by the secondary aggregate torque is subtracted from the engine torque and the Clutch actuator is controlled such that a deviation between the Coupling torque and the gripping torque decreases. 2. Procedure for setting the gripping point of a clutch actuator actuated clutch, which clutch actuator from an electronic Control device is controlled, the control device Clutch actuator controls such that one of an engine uses the clutch torque transmitted to a powertrain a predetermined gripper torque corresponds to the method in which the operating parameters of the engine from which the entire engine torque is determined, immediately before one Gripping point setting cycle when the clutch is fully open or the Powertrain picks up essentially no drive torque, and wuh the difference from the  two engine torques determined in this way and the clutch saktor is controlled such that a deviation between the difference and the gripping moment decreases. 3. The method of claim 2, wherein
the engine torque is determined at the beginning of a gripping point cycle,
the clutch actuator is actuated in such a way that the engine torque increases by the gripping torque,
the clutch actuator is moved back to its starting position and the engine torque is determined again and
the gripping point cycle is assessed as faulty if the initially and last determined engine torque differ by more than a predetermined amount. 4. The method of claim 2, wherein
the engine torque is determined at the beginning of a gripping point cycle,
the clutch actuator is actuated in such a way that the engine torque increases by the gripping torque and the engine speed is determined,
the clutch actuator is moved back to its starting position within a period of time that requires a speed control to regulate a torque fluctuation, the engine speed is determined again and
the gripping point cycle is evaluated as faulty if the last determined engine speed differs from the first determined engine speed in a predetermined manner. 5. Procedure for setting the gripping point of a clutch actuator actuated clutch, which clutch actuator from an electronic  Control device is controlled, the control device Clutch actuator controls such that one of an engine uses the clutch torque transmitted to a powertrain a predetermined gripper moment corresponds to the method in which the control device receives the Be driven by auxiliary units in such a way that their operation during a Gripping point setting cycle remains at least largely constant. 6. The method according to any one of claims 1 to 5, wherein a gripping point cycle at There are predetermined connection states of auxiliary units and / or Is blocked to consumers. 7. Method for setting the gripping point of a clutch actuator actuated clutch, which clutch actuator from an electronic Control device is controlled, the control device Clutch actuator controls such that one of an engine uses the clutch torque transmitted to a powertrain a predetermined gripper moment corresponds to which method, at least during the adjustment development of the clutch actuator in the closing direction of the clutch a vehicle brake is operated controlled from the control device. 8. Method for setting the gripping point of a clutch actuator actuated clutch, which clutch actuator from an electronic Control device is controlled, the control device Clutch actuator controls such that one of an engine uses the clutch torque transmitted to a powertrain a predetermined gripper torque corresponds to the method in which the braking torque of a drive Tool brake is detected and at least one actuation of the clutch actuator in the closing direction of the clutch does not occur when the braking torque falls below a predetermined value.   9. Procedure for adjusting the gripping point of one of a clutch actuator Tor operated clutch, which clutch actuator from an electronic Control device is controlled, the control device Coupling actuator for setting the gripping point controls such that a transmitted from an engine via the clutch to a drive train Moment corresponds to a predetermined gripping moment and the associated one Clutch actuator position is saved as a gripping point position, at which chem procedure the stored gripping point position by a predetermined Dimension adjusted in the direction of an opening of the clutch when one of the Clutch transmitted torque when approaching the stored gripping point slope exceeds a predetermined moment. 10. A method for setting the gripping point of a clutch motor arranged between a driving motor and a transmission and actuated by a motor actuator, comprising the following steps:

• - Opening the coupling up to a stored gripping point,
• - inserting a driving gear and measuring a value of an operating parameter,
• - Compare the measured value with a target value, and
• - Changing the gripping point in the event of a discrepancy between the measured value and the target value in the direction of reducing the discrepancy.

11. The method of claim 10, wherein the Einle force required to drive a synchronized transmission is measured.   12. Control device for controlling a clutch, by means of which an engine with a torque transmission leading to at least one vehicle wheel supply device is connectable, which control device at least with Operating parameters of the engine detecting sensors and a Coupling actuator is connected, memory with control programs and data contains and is constructed such that at least one method according to one of claims 1 to 9 can be carried out.