DE112012001718B4 - Method for adapting parameters of a clutch - Google Patents

Abstract

Method for adapting parameters of a clutch (8) of a dual clutch transmission system, which has a hydrostatic clutch actuator (1) with a pressure sensor (5), in a motor vehicle, the following steps being carried out: - closing and / or opening the clutch (8), - Detection of a pressure curve (210, 220, 230, 240) by means of the pressure sensor (5) and the position of the clutch (8) during the closing and / or opening of the clutch (8), - Adaptation of the parameters for the clutch (8) from the pressure curve (210, 220, 230, 240) and - using the adapted parameters in the subsequent operation of the clutch (8), characterized in that the adaptation of the parameters when the double clutch transmission system is first started up and / or the double clutch transmission system is started up again and / or when starting up of the vehicle and / or when the vehicle is shut down, in particular during the after-run and / or while the vehicle is in motion, the Pa The parameters "basic pressure hysteresis" and "pressure-pressure hysteresis" and "tactile point" and "stiffness" and "form factors" and "leaf spring force preload" are.

Description

The invention relates to a method having the features according to the preamble of claim 1.

The invention serves to determine the adaptive parameters of a hydrostatic clutch system at the end of the line.

In particular, the present invention describes the adaptation of parameters of a clutch of a double clutch transmission with a hydrostatic clutch system. Hydrostatic clutch systems are designed with a clutch actuator that has a pressure sensor, this is for example in 1 , in the DE 10 2010 047 800 A1 as well as the DE 10 2010 047 801 A1 shown. The clutch actuator is a so-called hydrostatic clutch actuator HCA (Hydrostatic Clutch Actuator). Such a hydrostatic actuator is to be understood as an actuator with a hydrostatic transmission path, for example a pressure line with hydraulic fluid. The pressure in the pressure line is recorded by the pressure sensor. If an element connected to it is to be moved by the hydrostatic actuator, hydraulic fluid is moved in the transmission path or the pressure line, for example caused by a piston in a master cylinder that moves a piston in a slave cylinder, coupled by the hydraulic fluid. If the element is to hold its position, the hydraulic fluid rests in the transmission path, so that the hydraulic fluid is in a hydrostatic state, which gives this actuator its name.

WO 2011/124 197 A1 discloses a method of controlling an automated clutch.

EP 2 159 440 A1 discloses a clutch control method for determining a correction amount.

DE 10 2008 041 353 A1 discloses a method for compensating for volume changes of a hydraulic fluid in a hydraulic actuating device for actuating a clutch.

DE 10 2007 024 794 A1 discloses a method for controlling the degree of engagement of an automated motor vehicle clutch.

DE 103 16 459 A1 discloses a method for controlling a transmission.

Usually, the commissioning of double clutch transmissions - as for example in the DE 10 2010 012 756 A1 is shown - complex and takes place with the help of moment signals. A gear test bench or roller test bench is generally required for full commissioning, which results in high costs. There is also a dependency on the accuracy of external torque signals.

The torque that can be transmitted by a clutch depends in particular on the path-clamping force characteristic. How such a path-clamping force characteristic curve can be learned with the aid of a pressure sensor signal during commissioning is, for example, in FIG DE 11 2012 001 711 A5 described.

• - Tastpunkt: Kupplungsposition, bei der ein vorgegebenes kleines Moment (z.B. 5Nm) oder dessen Kräfteäquivalent übertragen werden kann.
• - Steifigkeit: Skalierungsfaktor, mit dem die Steigung der Weg-Klemmkraft-Kennlinie verändert werden kann.
• - Formfaktoren: Skalierungsfaktoren, mit denen die Kraftwerte an den Weg-Stützstellen oberhalb des Tastpunkts verändert werden können.
• - Blattfederkraftvorlast: Blattfederkraft bei geöffneter Kupplung (Schnüffelbohrung in der hydraulischen Strecke jedoch geschlossen)

The modeling of the displacement-clamping force characteristic is based on a simple nominal displacement-force characteristic, which is characterized by the following parameters:

• - Touch point: clutch position at which a specified small torque (eg 5 Nm) or its force equivalent can be transmitted.
• - Stiffness: Scaling factor with which the gradient of the path-clamping force characteristic can be changed.
• - Form factors: Scaling factors with which the force values at the distance support points above the touch point can be changed.
• - Leaf spring force preload: Leaf spring force when the clutch is open (sniffer hole in the hydraulic section is closed, however)

The determination of these adaptive parameters at the end of the line enables a high level of torque accuracy and thus a high level of driving comfort even during the first use. In order to maintain this over the service life, the adaptive parameters listed above are also adapted during driving by algorithms for both clutches.

The two terms position-pressure characteristic curve and displacement-pressure characteristic curve and the two terms position-force characteristic curve and displacement-force characteristic curve are used synonymously in this document. The terms path or position relate to the actuator path along which the part of the actuator that moves the clutch - for example a piston in the master cylinder - moves.

The one mentioned above DE 11 2012 001 711 A5 does not describe the learning process for the adaptive parameters listed above with sufficient accuracy. In addition, there are other adaptive parameters whose learning process is in the DE 11 2012 001 711 A5 is not described.

All clutch parameters must be determined as best as possible during commissioning at the end of the line (vehicle or test bench) or in service so that they can be stored in the EEprom memory for further use during driving.

It is therefore the object of the present invention to specify a method for adapting clutch parameters of a dual clutch transmission which is inexpensive to use and preferably does not require a transmission test bench or roller test bench.

The object is achieved by a method having the features according to claim 1.

• - Schließen und/oder Öffnen der Kupplung,
• - Erfassen eines Druckverlaufs mittels des Drucksensors sowie der Position der Kupplung während dem Schließen und/oder Öffnen der Kupplung,
• - Adaption der Parameter für die Kupplung aus dem Druckverlauf und
• - Verwenden der adaptierten Parameter im anschließenden Betrieb der Kupplung.

According to the invention, a method for adapting parameters of a clutch of a dual clutch transmission system, which has a hydrostatic clutch actuator with a pressure sensor, is provided in a motor vehicle. According to the invention it is provided that the following steps are carried out:

• - closing and / or opening the clutch,
• - Detection of a pressure profile by means of the pressure sensor and the position of the clutch during the closing and / or opening of the clutch,
• - Adaptation of the parameters for the clutch from the pressure curve and
• - Use of the adapted parameters in the subsequent operation of the clutch.

With the method according to the invention, the parameter adaptation can also take place without a transmission test bench.

According to the invention, it is provided that the parameters are adapted when the double clutch transmission system is first started up and / or when the double clutch transmission system is started up again and / or when the vehicle is started up and / or when the vehicle is shut down, in particular during the after-run and / or while the vehicle is in motion, the parameters "Basic pressure hysteresis" and "pressure-pressure hysteresis" and "tactile point" and "stiffness" and "form factors" and "leaf spring force preload" are.

In a further preferred embodiment of the invention it is provided that the clutch is closed up to a predetermined pressure threshold and then fully opened again and / or that the clutch is opened up to a predetermined pressure threshold and then fully closed again.

In a further preferred embodiment of the invention it is provided that a path-pressure characteristic curve of the clutch is determined from the detected pressure curve, and that a path-engagement force characteristic curve of the clutch is determined from the determined path-pressure characteristic curve and that in the Position range of the displacement-engagement force characteristic curve in which the clutch is operated in the area of the clearance and does not yet transmit any torque, an approximation is carried out with a straight line that represents a displacement-leaf spring force characteristic curve, the parameter being derived from the displacement-leaf spring force characteristic curve "Leaf spring force preload" is determined as a functional value of the straight line at a position where the clutch is fully open and does not transmit any torque and the piston in the slave cylinder has passed the sniffer opening in the direction of clutch closing so that there is no connection between the pressure medium and the expansion tank.

In a further preferred embodiment of the invention it is provided that a path-pressure characteristic curve for closing the clutch and a path-pressure characteristic curve for opening the clutch at predetermined position support points, at which path-pressure value pairs are then used, from the recorded pressure curve are determined and that the "basic pressure hysteresis" parameter is the mean value of the differences in the path-pressure characteristic curve for closing and the path-pressure characteristic curve for opening at the position support points that are in a position range in which the path Pressure characteristics have a gradient that is smaller than a predetermined minimum gradient threshold value is determined.

In a further preferred embodiment of the invention it is provided that the parameter “pressure-pressure hysteresis” as differences between the value of the path-pressure characteristic curve for closing and the value of the path-pressure characteristic curve for opening, at maximum actuator position in the direction of the clutch Close, is determined.

In a further preferred embodiment of the invention it is provided that a clamping force characteristic of the clutch is determined by subtracting the determined path / leaf spring force characteristic of the clutch from the determined path / engagement force characteristic of the clutch.

In a further preferred embodiment of the invention it is provided that the parameter “touch point position” is determined by interpolation of the determined clamping force characteristic for a given touch point force, with a conversion into a corresponding force when a touch point torque is specified.

In a further preferred embodiment of the invention it is provided that the clamping force characteristic of the clutch is shifted in the position direction in such a way that the predetermined position characterizing the touch point on the position axis corresponds to the determined parameter "touch point position" and at position support points where displacement-pressure value pairs are present and which are above the touch point position in the direction of the clutch closing, the quotient of two force values is determined in each case, the one force value being determined as an interpolation of the clamping force characteristic curve and the second force value being determined as an interpolation of the shifted clamping force characteristic curve, and the value of the quotient in each case a parameter that is "preliminary form factors".

In a further preferred embodiment of the invention it is provided that the parameter “stiffness” is determined as the mean value from the determined parameters of the “preliminary form factors”.

In a further preferred embodiment of the invention it is provided that the parameters “final form factors” are determined from the parameters “preliminary form factors” by subtracting the parameter “stiffness”.

In a further preferred embodiment of the invention it is provided that a scaling factor is additionally taken into account when determining the parameters.

In a further preferred embodiment of the invention it is provided that the relationship between the clamping force of the clutch and the torque that can be transmitted by the clutch is detected by means of a torque signal during commissioning or in the subsequent operation of the clutch.

• 1 schematischer Aufbau eines hydrostatischen Kupplungssystems
• 2 Weg-Druck-Kennlinie
• 3 Modellierung: Weg-Druck-Kennlinie mit Druckhysterese
• 4 Identifikation der Adaptivparameter der Druckhysterese
• 5 Ermittlung der Klemmkraftkennlinie

Further advantages and advantageous embodiments of the invention are the subject of the following figures and their description.

• 1 schematic structure of a hydrostatic clutch system
• 2 Distance-pressure characteristic
• 3 Modeling: displacement-pressure characteristic with pressure hysteresis
• 4th Identification of the adaptive parameters of the pressure hysteresis
• 5 Determination of the clamping force characteristic

In 1 is a schematic of the structure of a hydraulic clutch system 1 using the example of a schematically illustrated hydraulic, hydrostatic clutch actuator (HCA) known from the prior art. This schematic representation only shows the structure for actuating one of the two clutches of a dual clutch transmission; the second clutch is actuated in the same way. The hydraulic clutch system 1 includes on the donor side 15th a control unit 2 that is an actuator 3 drives. When the actuator changes position 3 and the piston 19th in the cylinder 4th along the actuator path to the right is the volume of the cylinder 4th changed, whereby a pressure P in the cylinder 4th is built up via a pressure medium 7th via a hydraulic line 9 to the receiver side 16 the hydraulic clutch system 1 is transmitted. The hydraulic line 9 is adapted to the installation space of the vehicle with regard to its length and shape. On the recipient side 16 causes the pressure P of the pressure medium 7th in a cylinder 4 ' a change in path that occurs on a clutch 8th is transmitted to operate this. The pressure P in the cylinder 4th on the donor side 15th the hydraulic clutch system 1 can by means of a first sensor 5 be determined. With the first sensor 5 it is preferably a pressure sensor. The one from the actuator 3 The distance covered along the actuator path is measured by means of a second sensor 6th determined.

When the clutch is closed / opened once, measurement data are recorded in a suitable manner, based on which the adaptive parameters of the hydrostatic clutch system can be determined by suitable methods. This is detailed below.

Phase 1:

• Aus Speicherplatzgründen wird beim Schließen/Öffnen der Kupplung eine endliche Anzahl (z.B. 20) an Weg-Druck-Wertepaaren 230, 240 gespeichert. Zur Ermittlung können beispielsweise festen Wegwerte oder Wegdifferenzen vorgegeben werden. Ebenso ist auch die Vorgabe von festen Druckwerten oder Druckdifferenzen denkbar. Da die Weg-Druck-Kennlinien 210, 220 jedoch starke Gradientenänderungen aufweisen, ist eine Kombination aus Weg- und Druckvorgabe bzw. Wegdifferenzen- und Druckdifferenzenvorgabe vorteilhaft. Beispielsweise wird ein neues Weg-Druck-Wertepaar gespeichert, wenn sich entweder der Weg um 1 mm geändert hat oder aber der Druck um 1 bar. Somit wird der Weg-Druck-Kennlinienverlauf 210, 220 durch die endliche Anzahl an Wertepaaren 230, 240 gut abgebildet, wie 2 zu entnehmen ist.

Determination of the displacement-pressure characteristics when closing / opening the clutch:

• For reasons of memory space, a finite number (eg 20) of displacement-pressure value pairs is required when the clutch is closed / opened 230 , 240 saved. For example, fixed travel values or travel differences can be specified for the determination. The specification of fixed pressure values or pressure differences is also conceivable. Because the displacement-pressure characteristics 210 , 220 but have strong gradient changes, a combination of path and pressure specification or path difference and pressure difference specification is advantageous. For example, a new path / pressure value pair is saved if either the path has changed by 1 mm or the pressure has changed by 1 bar. The path-pressure characteristic curve is thus 210 , 220 by the finite number of value pairs 230 , 240 well illustrated how 2 can be found.

The displacement-pressure characteristics are used for closing and opening 230 , 240 stored in separate data arrays.

It is advantageous not to directly use the path and pressure signals 210 to save them, but rather to filter them 220 (eg PT1 filter) and - following the above procedure - then the filtered values 230 , 240 to save as well 2 can be found.

Phase 2:

• Neben den oben aufgeführten Adaptivparametern Tastpunkt, Steifigkeit, Formfaktoren sowie Blattfederkraftvorlast müssen weitere Adaptivparameter bestimmt werden. Das Weg-Kraft-Verhalten ist in realen Systemen abhängig von der Aktorbewegungsrichtung (Öffnen/Schließen), die Weg-Kraft-Kennlinie weist daher eine Hysterese auf. Ein einfaches Hysteresemodell ergibt sich durch folgende zwei Faktoren:
  • - Basis-Krafthysterese: Stellt eine Parallelverschiebung der Weg-Kraft-Kennlinie in Kraftrichtung in Abhängigkeit der Aktorbewegungsrichtung dar.
  • - Kraft-Krafthysterese: Zusätzliche Verschiebung der Weg-Kraft-Kennlinie in Kraftrichtung in Abhängigkeit von der gegebenen Kraft. Damit kann bei höheren Kräften eine größere Hysteresebreite erzielt werden.

Evaluation of the determined displacement-pressure characteristics 230 , 240 and determination of the coupling parameters:

• In addition to the adaptive parameters listed above, touch point, rigidity, form factors and leaf spring force preload, further adaptive parameters must be determined. The path-force behavior in real systems depends on the direction of movement of the actuator (opening / closing); the path-force characteristic therefore has a hysteresis. A simple hysteresis model results from the following two factors:
  • - Basic force hysteresis: represents a parallel shift of the path-force characteristic in the direction of force depending on the direction of movement of the actuator.
  • - Force-force hysteresis: Additional shift of the path-force characteristic in the direction of force depending on the given force. In this way, a larger hysteresis range can be achieved with higher forces.

Instead of using forces, pressures can also be used directly in the hysteresis model. The following adaptive parameters are thus obtained: basic pressure hysteresis, pressure-pressure hysteresis. This is in 3 shown.

Step 1: Determination of the pressure hysteresis (see Figure 4)

The measured pressure hysteresis results from the difference between the path-pressure characteristics 230 , 240 for closing and opening the clutch. The basic pressure hysteresis can be derived from the values for small actuator travel 440 , 420 can be determined by averaging. The pressure-pressure hysteresis can be derived from the values for medium and large actuator travel 430 can be determined by linear approximation. The adaptive parameter of the pressure-pressure hysteresis 450 corresponds to the value at the maximum actuator position (see 4th )

When driving, the current pressure hysteresis value results from the sum of the basic pressure hysteresis 420 and current pressure-pressure hysteresis 430 . The pressure-pressure hysteresis increases from zero at the touch point to the adaptive parameter of the pressure-pressure hysteresis at the maximum actuator position, preferably linearly.

Step 2: Determination of the touch point

The determination of a clamping force characteristic 530 takes place according to the above DE 11 2012 001 711 A5 - see also 5 of the present document.

• Die Weg-Druck-Kennlinie 210 in 2 zeigt eine typische Hysterese, die für die Bestimmung der Klemmkraftkennlinie 530 unerwünscht ist. Daher wird in einem ersten Schritt die Weg-Druck-Kennlinie 210 durch eine eindeutige Zuordnung approximiert, wie beispielsweise eine Mean-Fit-Approximation sodass sich eine mittlere Druckkennlinie ergibt.

The determination of the clamping force characteristic 530 is according to the DE 11 2012 001 711 A5 carried out as follows:

• The displacement-pressure characteristic 210 in 2 shows a typical hysteresis that is used to determine the clamping force characteristic 530 is undesirable. Therefore, the path-pressure characteristic curve is used in a first step 210 approximated by a clear assignment, such as a mean-fit approximation so that a mean pressure characteristic is obtained.

In the next step, the mean pressure curve is calculated by multiplying it by the area of the slave piston 19th the clutch actuator into an engagement force FEngage 510 ( 5 ) of the coupling converted. It becomes clear that an engaging force has to be applied even in the area of small clutch positions where the clutch does not yet transmit any torque. This force results from spring elements - usually leaf springs - which are attached to the clutch to safely separate the clutch disc and pressure plates. In order to transmit a torque to the clutch, the clutch pressure plates must first be moved towards one another against the leaf spring forces FLeafSpring so that contact with the clutch disc occurs. Only from this point on can a clamping force 530 and thus a frictional torque can be built up between the clutch disc and pressure plates.

If a force sensor is used instead of a pressure sensor, the path-force characteristic curve is similar to that of the path-pressure characteristic curve 210 shows. The further procedure is analogous to the procedure with the displacement-pressure characteristic 210 . The path-force characteristic is therefore approximated by a clear assignment, such as, for example, by the mean-fit approximation described above, so that a course is analogous 5 , namely the engagement force FEngage 510 the clutch as a function of the clutch position 550 results. In this way it has a characteristic 510 the engagement force FEngage of the clutch as a function of the clutch position 550 result with both a pressure sensor and a force sensor. The rest of the procedure can be carried out identically in both cases. The force sensor used can be integrated into the clutch actuator, for example, or can be located between the clutch actuator and the clutch, that is to say in particular between the clutch actuator and the pressure plate of the clutch, for example as a separate component Detection of the force transmitted from the actuator to the clutch.

The further procedure therefore consists in separating FEngage 510 into a leaf spring force FLeafSpring 520 as well as the clamping force FClamp. 530 . This process is carried out using 5 made clear.

As long as the clutch is operated in the area of the clearance, the engagement force 510 has a very low gradient. This area can be defined by a straight line 520 can be approximated (leaf spring force FLeafSpring 520 in 5 ).

As parameters of the leaf spring straight line 520 the result is the slope and, as an adaptive parameter of the leaf spring force preload, the functional value of the straight line 520 at a position where the clutch is fully open and the piston 19th in the slave cylinder 4th the sniffer opening 18th has passed in the direction of clutch closing, so that no connection of the pressure medium 7th to the expansion tank 17th consists.

After this preliminary work, the clamping force curve is obtained 530 by subtracting the leaf spring force curve 520 from the engagement force curve 510 . The result is given by the clamping force characteristic (FClamp curve) 530 in 5 made clear.

The touch point position is now obtained by interpolating the clamping force characteristic 530 for a given touch point force. If, on the other hand, a touch point torque - for example 5 Nm - is specified, this must first be converted into a touch point force.

Step 3: Identify the preliminary form factors

First, the nominal clamping force characteristic stored in the control unit (standard clamping force characteristic for the respective clutch without adjustments) is shifted in the position direction in such a way that the touch point corresponds to the previously determined value. For the position support points above the touch point, interpolation of the measured clamping force characteristic curve determined above 530 Force values determined. The quotients from these force values and the associated forces of the nominal clamping force characteristic result in the preliminary form factors.

Step 4: Determination of the stiffness

In principle, the stiffness is the ratio of the gradients of the measured clamping force characteristic and the nominal clamping force characteristic.

This results directly as the mean value of the preliminary form factors. Due to the integer arithmetic, a scaling factor is optionally taken into account.

Step 5: determine the final form factors

The final form factors result from the preliminary form factors by subtracting the previously calculated mean value from them. Due to the integer arithmetic, a scaling factor is optionally taken into account.

The method is not limited to being carried out only at the end of the line. It would also be advantageous to carry this out on a regular basis while the vehicle is in motion, in particular before the journey (but reduces availability) or immediately after the journey (after the journey).

A method is therefore proposed for determining the adaptive parameters of a hydrostatic clutch system at the end of the line by closing / opening the clutch and evaluating the resulting pressure-travel characteristic.

List of reference symbols

1

Hydraulic clutch system

2

Control unit

3

Actuator

4, 4 '

cylinder

5

first sensor

6th

second sensor

7th

Pressure medium

8th

coupling

9

Hydraulic line

10

Distance-pressure characteristic

15th

Donor side

16

Recipient side

17th

surge tank

18th

Sniffer opening

19th

Pistons

210

Distance-pressure characteristic

220

filtered displacement-pressure characteristic

230

Distance-pressure value pairs: Closing the clutch

240

Distance-pressure value pairs: opening of the clutch

310

Basic pressure hysteresis: Closing the clutch

320

Basic pressure hysteresis: opening the clutch

330

Basic pressure hysteresis + pressure-pressure hysteresis: Closing the clutch

340

Basic pressure hysteresis + pressure-pressure hysteresis: opening the clutch

410

Pressure hysteresis measured

420

Basic pressure hysteresis

430

Pressure-pressure hysteresis

440

Adaptive parameters of the basic pressure hysteresis

450

Adaptive parameters of the pressure-pressure hysteresis

510

FEngage: Clutch engagement force

520

FLeafSpring: leaf spring force

530

FClamp: clamping force

540

FClutch: forces on the clutch

550

LClutch: clutch actuator position

Claims (12)

Method for adapting parameters of a clutch (8) of a dual clutch transmission system, which has a hydrostatic clutch actuator (1) with a pressure sensor (5), in a motor vehicle, the following steps being carried out: - closing and / or opening the clutch (8), - Detection of a pressure curve (210, 220, 230, 240) by means of the pressure sensor (5) and the position of the clutch (8) during the closing and / or opening of the clutch (8), - Adaptation of the parameters for the clutch (8) from the pressure curve (210, 220, 230, 240) and - using the adapted parameters in the subsequent operation of the clutch (8), characterized in that the adaptation of the parameters when the double clutch transmission system is first started up and / or the double clutch transmission system is started up again and / or when starting up of the vehicle and / or when the vehicle is shut down, in particular during the after-run and / or while the vehicle is in motion, wherein d he parameters are "basic pressure hysteresis" and "pressure-pressure hysteresis" and "tactile point" and "stiffness" and "form factors" and "leaf spring force preload". Procedure according to Claim 1 , characterized in that the clutch is closed up to a predetermined pressure threshold and then fully opened again and / or in that the clutch is opened up to a predetermined pressure threshold and is then fully closed again. Method according to one of the Claims 1 until 2 , characterized in that a path-pressure characteristic curve (210, 220, 230, 240) of the clutch is determined from the detected pressure curve, and that a path is determined from the determined path-pressure characteristic curve (210, 220, 230, 240) Engagement force characteristic curve (510) of the clutch is determined and that an approximation with a straight line (520) is carried out in the position range of the path-engagement force characteristic curve (510) in which the clutch is operated in the area of the clearance and does not yet transmit any torque which represents a path-leaf spring force characteristic curve (520), the parameter "leaf spring force preload" as a function value of the straight line (520) at a position at which the clutch is fully open and no torque from the path-leaf spring force characteristic curve (520) transmits and the piston (19) in the slave cylinder (4) has passed the sniffer opening (18) in the direction of clutch closing, so that there is no connection between the pressure medium (7) and the expansion tank (17) is determined. Method according to one of the Claims 1 until 3 , characterized in that a path-pressure characteristic curve (230) for closing the clutch and a path-pressure characteristic curve (240) for opening the clutch at predetermined position support points, at which path-pressure value pairs are then used, from the recorded pressure curve (230,240) are available and that the parameter “base pressure hysteresis” (440) as the mean value of the differences in the path-pressure characteristic curve (230) for closing and the path-pressure characteristic curve (240) for opening at the Position support points (230, 240) which lie in a position range in which the displacement-pressure characteristics (210, 220, 230, 240) have a gradient that is smaller than a predetermined minimum gradient threshold value is determined. Procedure according to Claim 4 , characterized in that the parameter “pressure-pressure hysteresis” (450) as differences between the value of the path-pressure characteristic curve (230) for closing and the value of the path-pressure characteristic curve (240) for opening, at the maximum actuator position in the direction of clutch closing, is determined. Method according to one of the Claims 3 until 5 , characterized in that a clamping force characteristic (530) of the clutch is determined by subtracting the determined path-leaf spring force characteristic (520) of the clutch from the determined path-engagement force characteristic of the clutch (510). Procedure according to Claim 6 , characterized in that the "touch point position" parameter is determined by interpolating the Clamping force characteristic (530) is determined for a predetermined touch point force, with a conversion into a force corresponding thereto taking place when a touch point torque is specified. Method according to one of the Claims 6 until 7th , characterized in that the clamping force characteristic curve (530) of the clutch is shifted in the position direction in such a way that the predetermined position characterizing the touch point on the position axis corresponds to the determined parameter "touch point position" and wherein at position support points where displacement-pressure value pairs (230,240) are present and which are above the touch point position in the direction of the clutch closing, the quotient of two force values is determined in each case, the one force value being determined as an interpolation of the determined clamping force characteristic curve (530) and the second force value being determined as an interpolation of the shifted clamping force characteristic curve, and the value of the quotient is a parameter of “preliminary form factors”. Procedure according to Claim 8 , characterized in that the parameter "stiffness" is determined as the mean value from the determined parameters of the "preliminary form factors". Method according to one of the Claims 8 until 9 , characterized in that the "final form factors" parameters are determined from the "preliminary form factors" parameters by subtracting the "stiffness" parameter. Method according to one of the Claims 9 or 10 , characterized in that a scaling factor is also taken into account when determining the parameters. Method according to one of the Claims 1 until 11 , characterized in that the relationship between the clamping force of the clutch and the torque that can be transmitted by the clutch is detected by means of a torque signal during commissioning or in the subsequent operation of the clutch.

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