DE102012209869A1 - Method for monitoring a clutch - Google Patents

Abstract

Method for monitoring a clutch, in particular a power shift clutch of a drive train of a motor vehicle, wherein the clutch upstream of an engine output shaft and a transmission input shaft of a transmission of the drive train is connected downstream.

Description

The invention relates to a method with the features according to the preamble of claim 1 and a transmission with the features according to the preamble of claim 12.

Methods for monitoring a clutch, in particular a power shift clutch, a drive train of a motor vehicle are known. In this case, for example, an engagement point of the power-shift clutch can be determined by means of a speed gradient of the transmission input shaft. It is known to engage the power shift clutch while watching a speed behavior of the transmission input shaft to conclude from it to the touch point of the power shift clutch. The DE 10 2007 025 253 A1 relates to a method for determining the engagement point of a clutch of an automated dual-clutch transmission of a vehicle while the drive unit is running. The DE 199 39 818 C1 relates to a method of controlling a powertrain of a vehicle in which a power-shift clutch for torque transmission is engaged during travel and the engagement point of a parallel disengaged power-shift clutch is determined by a transient engagement operation. The EP 1 741 950 A1 relates to a method for determining a gripping point of a clutch. The procedure starts with a fully closed clutch and determines two coupling positions, which are closely spaced in time and both enter into the calculation of the gripping point. While the clutch position is determined when closing the clutch, the clutch is opened when determining the clutch position. Furthermore, methods for a clutch characteristic adaptation are known. The DE 103 08 517 A1 relates to a method for clutch characteristic adaptation of an automated dual-clutch transmission, in particular of a motor vehicle, with the engine running. The EP 1 067 008 B1 relates to a method for clutch characteristic adaptation of an automated dual-clutch transmission, in particular of a motor vehicle, wherein in particular a speed gradient of a free transmission input shaft is determined.

It is the clutch-side and the transmission-side drag torque acting on the transmission input shaft to be calculated in selected situations.

In particular, the clutch and transmission-side drag torque of the transmission input shafts should be determined in selected situations in a dual-clutch system. The object of the invention is to enable improved monitoring of a clutch, in particular a power shift clutch, of a drivetrain of a motor vehicle, in particular a state of the driveline and / or the To identify power shift clutch.

The object is achieved by a method having the features according to claim 1 and by a gear having the features according to claim 12.

In procedural terms, the object is achieved by the method described below.

According to the invention, a method is provided for monitoring a clutch, in particular a power shift clutch of a drive train of a motor vehicle, wherein the clutch is connected upstream of an engine output shaft and a transmission input shaft of a transmission of the drive train is connected downstream. According to the invention, the following steps are provided:
Keeping the clutch of the transmission open,
Laying out a gear of the gearbox,
Determining a rotational acceleration _quantity (ω, _Ips1 , ω, _Ips2 ) characterizing a rotational acceleration _{behavior of} the transmission _input shaft of the transmission
Storing the calculated rotational acceleration variable (ω. _IPS1, ω. _IPS2) or a variable derived therefrom (M _{SumInaktivUnterMotorIps1,} M _{SumInaktivÜberMotorIps1,} M _{SumInaktivUnterMotorIps2,} M _{SumInaktivÜberMotorIps2)} under allocation of a designation of the transmission, and with assignment of the information as to whether the rotational speed of the transmission input shaft of the transmission is greater than or less than the rotational speed of the motor output _shaft at the time of determining the rotational acceleration _quantity (ω, _Ips1 , ω, _Ips2 ) in a non-volatile memory.

By the name of the transmission can be understood, for example, the identification of a partial transmission, for example, by the transmission input shaft.

In a preferred embodiment of the invention, it is provided that the determination of the rotational acceleration _variable (ω, _Ips1 , ω, _Ips2 ) takes place by means of a rotational speed _{sensor device} assigned to the transmission _input shaft.

In a further preferred embodiment of the invention it is provided that the method is carried out in the presence of a positive and in the presence of a negative speed difference between the speed of the transmission input shaft of the transmission and the engine output shaft, wherein a positive speed difference is present when the speed of the transmission input shaft of the transmission smaller is the speed of the engine output shaft and wherein there is a negative speed difference when the speed of the transmission input shaft of the transmission is greater than the speed of the engine output shaft.

In a further preferred embodiment of the invention it is provided that the determination of a rotational acceleration _variable (ω, _Ips1 , ω, _Ips2 ) characterizing a rotational acceleration _{behavior of} the transmission _input shaft of the transmission immediately after the gearbox has been geared out within a period of less than 1.5 seconds is preferred within 0.5 seconds after the gear is laid out.

In a further preferred embodiment of the invention, it is provided that the rotational acceleration _variable (ω, _Ips1 , ω, _Ips2 ) is a rotational speed _gradient or an angular acceleration.

In a further preferred embodiment of the invention, it is provided that a _variable derived from the determined rotational acceleration _variable (ω, _Ips1 , ω, _Ips2 ) is a total torque (M _{SumInactiveUnterMotorIps1} , M _{SumInactiveAberMotorIps1} , M _{SumInactiveUnterMotorIps2} , M _{SumInactiveAberMotorIps2} ) of the transmission _input shaft of the transmission.

In a further particularly preferred embodiment of the invention, it is provided that the transmission is a partial transmission of a dual-clutch transmission with two partial transmissions and two transmission input shafts Ips1 or Ips2 and two partial clutches,
where a drag torque (M _DragCl1 , M _DragGBox1 , M _DragCl2 , M _DragGBox2 ) is determined as a function of total torques (M _{SumInactiveUnterMotorIps1} , M _{SumInactiveAberMotorIps1} , M _{SumInaktivUnterMotorIps2} , M _{SumInaktivÜberMotorIps2} ),
wherein a clutch-side drag torque (M _DragCl1 , M _DragCl2 ) is determined at a transmission input shaft Ips1 or Ips2 by means of the following formula: M _DragCl1 = (M _{SumInactiveUnterMotorIps1} - M _{SumInactiveUberMotorIps1} ) / 2 M _DragCl2 = (M _{SumInactiveUnterMotorIps2} - M _{SumInactiveUberMotorIps2} ) / 2 and / or wherein a transmission-side drag torque (M _DragGBox1 , M _DragGBox2 ) is determined at a transmission input shaft Ips1 or Ips2 by means of the following formula, M _DragGBox1 = - (M _{SumInactiveUnterMotorIps1} + M _{SumInactiveUberMotorIps1} ) / 2 or M _DragGBox2 = - (M _{SumInactiveUnterMotorIps2} + M _{SumInactiveUberMotorIps2} ) / 2 the partial clutch of the partial transmission having the other transmission input shaft Ips1 or Ips2 is closed,
where MSumInactiveUnterMotorIps1 is the sum moment at the transmission input shaft Ips1 and according to the formula ω. _Ips1 J _Ips1 = M _{SumInactiveUnterMotorIps1 is} detected,
this value being from the stored value of the rotational acceleration _quantity ( _ω.Ips1 ) associating the transmission with the transmission input shaft Ips1 and associating the information that the rotational speed of the transmission input shaft Ips1 of the transmission is smaller than the rotational speed of the engine output shaft at the time of determining the rotational acceleration magnitude (ω _Ips1 ) is determined
where M _{SumInaktivÜberMotorIps1 is} the sum moment at the transmission input shaft Ips1 and according to the formula ω. _Ips1 J _Ips1 = M _{SumInactiveAutMotorIps1 is} detected,
this value being from the stored value of the rotational acceleration _quantity ( _ω.Ips1 ) associating the transmission with the transmission input shaft Ips1 and associating the information that the rotational speed of the transmission input shaft Ips1 of the transmission is greater than the rotational speed of the engine output shaft at the time of determining the rotational acceleration magnitude (ω _Ips1 ) is determined
where M _{SumInaktivUnterMotorIps2 is} the sum moment at the transmission input shaft Ips2 and according to the formula ω. _Ips2 J _Ips2 = M _{SumInactiveUnterMotorIps2 is} determined
this value being from the stored value of the rotational acceleration _quantity ( _ω.Ips2 ) associating the transmission with the transmission input shaft Ips2 and associating the information that the speed of the transmission input shaft Ips2 of the transmission is smaller than the speed of the motor output shaft at the time of determining the spin magnitude (ω _Ips2 ) is determined
where M _{SumInaktivÜberMotorIps2 is} the sum moment at the transmission input shaft Ips2 and according to the formula ω. _Ips2 J _Ips2 = M _{SumInactiveAboveMotorIps2 is} determined
this value being from the stored value of the rotational acceleration _quantity ( _ω.Ips2 ) associating the transmission with the transmission input shaft Ips2 and associating the information that the speed of the transmission input shaft Ips2 of the transmission is smaller than the speed of the motor output shaft at the time of determining the spin magnitude (ω _Ips2 ) is determined
and where J _{Ips1 denotes} the moment of inertia of the transmission input shaft Ips1 and J _{Ips2 denotes} the moment of inertia of the transmission input shaft Ips2.

In a further preferred embodiment of the invention it is provided that instead of storing the detected rotational acceleration variable (ω. _IPS1, ω. _IPS2) or a variable derived therefrom (M _{SumInaktivUnterMotorIps1,} M _{SumInaktivÜberMotorIps1,} M _{SumInaktivUnterMotorIps2,} M _{SumInaktivÜberMotorIps2)} before storing weighting the determined spin _magnitude (ω. _Ips1 , ω. _Ips2 ) or one derived therefrom with the previously stored value, wherein the weighting is preferably carried out with a weighting factor of 9/0 or 1/2 for the already stored value and 1/10 or 1/2 for the determined not yet stored value and then the weighted Value is stored so that there is a smoothing of the value.

In a further preferred embodiment of the invention it is provided that the determination of the coupling-side drag torque (M _DragCl1 , M _DragCl2 ) and / or the transmission-side drag torque (M _DragGBox1 , M _DragGBox2 ) takes place during a neutral _{phase of} the transmission.

In a further preferred embodiment of the invention, it is provided that the method for multiple gear changes of the transmission is performed several times, in particular in different directions.

In a further preferred embodiment of the invention, it is provided that a threshold value for the clutch-side drag torque (M _DragCl1 , M _DragCl2 ) is provided and when the threshold value is exceeded by the amount of the clutch-side drag torque is detected to be present on a drag torque at the respective clutch, said Threshold is preferably 1 NewtonMeter.

The advantage of the present invention is that, for example, higher-level methods such as, for example, methods for adapting the touch point of a clutch or method for determining the required synchronization force during gear engagement information about the presence and / or the size of a clutch-side drag torque and / or a transmission-side drag torque are supplied.

The object is further achieved with a transmission, in particular a dual-clutch transmission, designed, designed and / or constructed for carrying out a method described above, solved. This results in the advantages described above.

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

They show in detail:

1 partially illustrated torque flow diagram of a dual-clutch transmission of a drive train of a motor vehicle

2 Time course of the measured and calculated quantities

1 shows a torque flow diagram of a transmission 1 , the part of a driveline only partially shown 3 a likewise only partially illustrated motor vehicle 5 is. The gear 1 is designed as a dual-clutch transmission and has a first partial transmission 7 and a second partial transmission 9 on. The driveline has one by means of the reference numeral 11 merely indicated drive source. The drive source 11 drives an engine output shaft 13 on, which is a power shift clutch 15 is downstream. The power shift clutch 15 has a first part clutch 17 and a second, separately controllable by this partial coupling 19 on. At the partial clutches 17 . 19 these may be, in particular, dry or fluid couplings, in particular multi-disc clutches. In particular, the power shift clutch 15 be designed partially automated or automated operable.

The first part clutch 17 the power shift clutch 15 is the first partial transmission 7 downstream. The second part clutch 19 the power shift clutch 15 is the second partial transmission 9 downstream. By means of partial transmissions 7 . 9 of the transmission 1 Ranges can be engaged, for example by means of the first sub-transmission 7 odd speed steps and by means of the second partial transmission 9 straight gears and possibly a reverse gear. To change the gears or gears of the transmission 1 can the partial clutches 17 . 19 the power shift clutch 15 alternately closed or opened.

The partial transmissions 7 . 9 is a common transmission output shaft 21 downstream, by means of the drive wheels of the motor vehicle 5 are drivable.

Between the power shift clutch 15 and the gearbox 1 is a transmission input shaft 23 connected. The transmission input shaft is designed as a double shaft in the form of a hollow shaft, wherein between the first part clutch 17 and the first partial transmission 7 an inner shaft 25 Ips1 of the transmission input shaft 23 and between the second part clutch 19 and the second partial transmission 9 an outside wave 27 Ips2 of the transmission input shaft 23 are switched. By means of a speed sensor device 55 can the speed of the inner shaft 25 and the speed of the outer shaft 27 the transmission input shaft 23 be determined.

At the engine output shaft 13 is an engine torque 29 _Mot . The engine torque 29 _Mot , for example, from the drive source 11 be generated or as a drag torque at this issue. The output is indicated by the gearbox 1 an output torque 31 M _down to.

The transmission input shaft 23 is each on the outside wave 27 via a housing bearing 33 and the inner shaft 25 via a housing bearing 51 stored on the housing. The outside wave 27 Ips2 is against the inner shaft 25 Ips1 about an interim storage 34 stored. On the outside wave 27 induces the housing bearing 33 an external bearing moment 37 M _{BearingsGearboxIps2} . On the inner shaft 25 acts an external bearing moment 53 M _{BearingsGearboxIps1} . Both outer bearing moments 37 M _{bearing gearbox housing Ips2} and 53 M _{BearingsGearboxesIps1} always have a braking effect.

Next acts between the outer shaft 27 Ips2 and the inner shaft 25 Ips1 a moment 35 M _{bearing Ips1Ips2} or M _{bearing Ips2Ips1 of} the intermediate storage 34 , The effective direction of the moment 35 depends on which shaft turns faster. The warehouse 34 between the inner shaft 25 and the outside wave 27 can have a braking or accelerating effect, so that the bearing moment 35 accelerating or braking effect, depending on which of the waves 25 and 27 turns faster. Therefore, depending on the speed ratios of the inner shaft 25 and the outside wave 27 the transmission input shaft 23 Sign change in bearing moment 35 occur.

By means of the reference symbols i1 and i2 are in 1 the different translations of the partial transmission 7 and 9 symbolizes.

In addition, the transmission input shaft 23 , which moves in a transmission oil, braked due to churning losses, being on the inner shaft 25 a first plan torque 43 M _{gear oil Ips1} and on the outer _shaft 27 a second plan torque 45 M _gear oil Ips2 is applied. Both plan moments 43 M _{gear oil Ips1} and 45 M _{GetriebeölIps2} thus always have a braking effect.

With the power shift clutch open 15 or open part-load couplings 17 and 19 is located at the first part clutch 17 a first clutch drag torque 47 M _Cl1 and at the second part clutch 19 a second clutch drag torque 49 M _Cl2 on.

J _Ips1 denotes the moment of inertia of the inner _shaft 25 Ips1, J _Ips2 the moment of inertia of the external _shaft 27 IPS2 ,. ω. _Ips1 and ω. _Ips2 denote the speed _{gradient of} the respective transmission _input shaft.

To determine the torque acting on the transmission input shaft in suitable situations and to calculate therefrom the clutch as well as the transmission-side drag torque. The essential point to the solution of the problem is to combine the individual moments to an easily calculable coupling and transmission-side drag moment and smooth the summation moments suitable and initialize.

In the following, suitable situations for the calculation of the moment acting on the transmission input shaft are described:
The calculation of the drag torque on the inactive transmission input shaft can be carried out when the associated clutch is open, and the gear in this partial transmission has just been designed (in the context of this document, this clutch as inactive clutch, that transmission input shaft as the inactive transmission input shaft and that partial transmission as inactive Teilgetriebe called), as long as the gear is engaged on the gear ratio, a solid slip between the waves is enforced. On the active clutch, the slip in this situation must be very small, so that the assumption is that the active transmission input shaft (transmission input shaft of the sub-transmission that is associated with the active clutch) rotates with the engine. The transmission input shaft speed of the active transmission input shaft thus corresponds to the speed of the drive motor.

All moments are considered constant for the observation period - usually a time interval of about 0.5 seconds in length - immediately after the gear layout. This time is usually sufficient to determine the summation moment from the speed gradient. The moments in the bearings to the gear housing and the friction torque in the transmission oil are strictly dependent on the respective speed of the transmission input shaft, the moments in the bearings between the two transmission input shafts are dependent on the slip speed between the two transmission input shafts. From measurements you can see that this speed dependence does not matter. In the period of observation, the considered transmission input speed of the inactive transmission input shaft changes linearly to a first approximation, which suggests that the speed dependence is negligible.

The following describes the calculation of the clutch-side and transmission-side drag torque at the transmission input shaft:
The friction of the transmission _{input shafts} in the housing _bearings M _bearing gearbox housing _Ips1 for shaft 1 (Ips1) and M _bearing gearbox housing _Ips2 for shaft 2 (Ips2) ensure that a rotating transmission input shaft Ips1 or Ips2 is decelerated. The friction torques M _{gear oil of} the gears in the transmission against the transmission oil also have a braking effect.

• a) Liegt die Drehzahl der Getriebeeingangswelle der inaktiven Welle unter der Motordrehzahl, dann gilt ω ._Ips1J_Ips1 = M_Cl1 + M_{LagerIps1Ips2} – M_{LagerGetriebegehäuseIps1} – M_{GetriebeölIps1} für Welle 1 und ω ._Ips2J_Ips2 = M_Cl2 + M_{LagerIps2Ips1} – M_{LagerGetriebegehäuseIps2} – M_{GetriebeölIps2} für Welle 2.
• b) Liegt die die Getriebeeingangswelle der inaktiven Welle über der Motordrehzahl, dann gilt ω ._Ips1J_Ips1 = –M_Cl1 – M_{LagerIps1Ips2} – M_{LagerGetriebegehäuseIps1} – MGetriebeölIps1 für Welle 1 und ω ._Ips2J_Ips2 = M_Cl2 – M_{LagerIps2Ips1} – M_{LagerGetriebegehäuseIps2} – M_{GetriebeölIps2} für Welle 2.

Two cases have to be distinguished:

• a) If the speed of the transmission input shaft of the inactive shaft is below the engine speed, then applies ω. _Ips1 J _Ips1 = M _Cl1 + M _{Bearing Ips1Ips2} - M _{Bearing Gearbox Ips1} - M _{Gearbox oilps1} for shaft 1 and ω. _Ips2 J _Ips2 = M _Cl2 + M _{Bearing Ips2Ips1} - M _{BearingGearboxIps2} - M _{Gear OilIps2} for shaft 2.
• b) If the transmission input shaft of the inactive shaft is above the engine speed, then applies ω. _Ips1 J _Ips1 = -M _Cl1 - M _{Bearings Ips1Ips2} - M _{BearingsGearboxesIps1} - Gearbox oil Ips1 for shaft 1 and ω. _Ips2 J _Ips2 = M _Cl2 - M _{Bearing Ips2Ips1} - M _{BearingGearboxIps2} - M _{Gear oilIps2} for shaft 2.

One grasps the clutch-side moments
M _DragCl1 = M _Cl1 + M _{bearingsIps1Ips2} and M _DragCl2 = M _Cl2 + M _{bearingsIps2Ips1} together, as well as the _transmission -side drag torque M _DragGBox1 = M _{bearing gearbox housing Ips1} + M _{gear oil Ips1} and M _DragGBox2 = M _{bearing gearbox housing Ips2} + M _{gear oil Ips2} .

• a) Getriebeeingangswelle der inaktiven Welle unter der Motordrehzahl ω ._Ips1J_Ips1 = M_DragCl1 – M_DragGBox1 ω ._Ips2J_Ips2 = M_DragCl2 – M_DragGBox2
• b) Getriebeeingangswelle der inaktiven Welle über der Motordrehzahl ω ._Ips1J_Ips1 = –M_DragCl1 – M_DragGBox1 ω ._Ips2J_Ips2 = –M_DragCl2 – M_DragGBox2

With the simplifications:

• a) transmission input shaft of the inactive shaft below the engine speed ω. _Ips1 J _Ips1 = M _DragCl1 - M _DragGBox1 ω. _Ips2 J _Ips2 = M _DragCl2 - M _DragGBox2
• b) transmission input shaft of the inactive shaft above the engine speed ω. _Ips1 J _Ips1 = -M _DragCl1 - M _DragGBox1 ω. _Ips2 J _Ips2 = -M _DragCl2 - M _DragGBox2

The sum moment determinable at the transmission input shaft results from the consideration of the speed gradient in a) to ω. _Ips1 J _Ips1 = M _{SumInactiveUnterMotorIps1} , in the same way this applies to b).

• a) Getriebeeingangswelle der inaktiven Welle unter der Motordrehzahl M_{SumInaktivUnterMotorIps1} = M_DragCl1 – M_DragGBox1 M_{SumInaktivUnterMotorIps2} = M_DragCl2 – M_DragGBox2
• b) Getriebeeingangswelle der inaktiven Welle über der Motordrehzahl M_{SumInaktivÜberMotorIps1} = –M_DragCl1 – M_DragGBox1 M_{SumInaktivÜberMotorIps2} = –M_DragCl2 – M_DragGBox2

With the simplifications:

• a) transmission input shaft of the inactive shaft below the engine speed M _{SumInactiveUnterMotorIps1} = M _DragCl1 - M _DragGBox1 M _{SumInactiveUnterMotorIps2} = M _DragCl2 - M _DragGBox2
• b) transmission input shaft of the inactive shaft above the engine speed M _{SumInactiveAboutMotorIps1} = -M _DragCl1 - M _DragGBox1 M _{SumInactiveAboutMotorIps2} = -M _DragCl2 - M _DragGBox2

The summation torque is known from the evaluation of the transmission input speed gradient. It is thus a linear equation system with two equations and two unknowns.

The coupling-side drag torque on the transmission input shafts can thus be determined M _DragCl1 = (M _{SumInactiveUnterMotorIps1} - M _{SumInactiveUberMotorIps1} ) / 2 M _DragCl2 = (M _{SumInactiveUnterMotorIps2} - M _{SumInactiveUberMotorIps2} ) / 2

The transmission-side drag torque on the transmission input shafts can thus be determined M _DragGBox1 = - (M _{SumInactiveUnterMotorIps1} + M _{SumInactiveUberMotorIps1} ) / 2 or M _DragGBox2 = - (M _{SumInactiveUnterMotorIps2} + M _{SumInactiveUberMotorIps2} ) / 2 wherein the summation moments - for example M _{SumInaktivUnterMotorIps1} - as already described above from the evaluation of the transmission _{input speed gradient} ω. _Ips1 J _Ips1 = M _{SumInactiveUnterMotorIps1 of} the corresponding transmission input shaft Ips1 25 or Ips2 27 by means of the speed sensor device 55 results. Analogously, this also applies to the other summation moments.

Is the amount of the clutch-side drag torque | M _DragCl1 | or | M _DragCl2 | greater than a threshold z. B. 1 Nm, then drag torque can be reported to the parent strategies such as a method for Tastpunktadaption the clutch or a method for determining the necessary synchronization force when engaging.

If the drag torque is too high, this can also be entered in the fault memory, thus causing a replacement of the clutch.

The two summation moments per partial clutch 17 . 19 or transmission input shaft 25 . 27 - z. B. M _{SumInaktivUnterMotorIps1} and M _{SumInaktivÜberMotorIps1} for transmission input shaft Ips1 25 - Are not determined simultaneously but as described above, inter alia, depending on the present speed ratios. However, the two cumulative moments per sub-clutch must be available directly after the control unit start, from the beginning to the two drag torques - the clutch-side and the gearbox-side drag torque - the respective shaft 25 . 27 to be able to determine. It therefore offers these four values - the two Total moments per partial clutch - to be stored in the EEPROM and to combine the new value with the old value for each successful cumulative torque determination. This can be done, for example, in such a way that the old value currently present in the EEPROM with a weighting of 9/10 and the value currently determined from the summation torque determination is added to a new value with a weighting of 1/10 and then the old value currently present in the EEPROM Value is overwritten with the new value. This corresponds to a smoothing of the value at the event discrete times when the gear is designed. Another example of weighting would be 1/2 and 1/2. The smoothing also prevents the detection of the drag torque when exceeding the torque threshold leads to a toggling recognition / failure to detect drag torque. It is assumed that drag torques change in the form of a slow drift so that several circuits are sufficient to follow this drift. The choice of the weighting factors is left to the expert, taking into account the technical case.

Looking at the first transmission input shaft Ips1 in 2 , it can be seen on the course of the measured quantity M _{SumInaktivUnterMotorIps1} 103 a constant course, whereas M _{SumInaktivÜberMotorIps1} 104 actively changes. The calculated sizes M _DragCl1 102 and M _DragGBox1 101 depict these courses. This underlines the need to store the measured quantities in the EEPROM so that they are available after the control unit has started. By more smoothing of the measured quantities, a smoothing of the calculated quantities can likewise be achieved.

Alternative to the present invention: Although it can be produced with a high effort schleppmomentenfreie couplings, however, a significant bearing friction between the transmission input shafts will be measurable at the latest with increased wear.

By measuring the transmission input shaft speed gradient in situations where the inactive clutch is open, the gear in the inactive sub-transmission was designed immediately prior to the measurement, and the active clutch is closed, in the event that the inactive transmission input shaft rotates faster than the engine and for the case that it rotates slower than the engine, depending on an effective moment on the transmission input shaft are closed. With these two measured moments per transmission input shaft, a system of equations with two equations and the two unknowns can be formulated and solved. The two unknowns represent the coupling and transmission-side drag torque. Only a filtering of the measured variables and storing them in the EEPROM but allow a continuous determination of the drag torque at any time.

LIST OF REFERENCE NUMBERS

1

transmission

3

drive train

5

motor vehicle

7

first partial transmission

9

second partial transmission

11

a drive source

13

Motor output shaft

15

Load clutch

17

first part clutch

19

second part clutch

21

Transmission output shaft

23

Transmission input shaft

25

inner shaft

27

outer shaft

29

engine torque

31

output torque

33

Housing bearing outer shaft

34

Intermediate bearing outer shaft against inner shaft

35

inner bearing moment (moment of the intermediate bearing)

37

outer bearing moment

43

Planing torque inner shaft

45

Face torque outer shaft

47

Drag torque of the first part clutch

49

Drag torque of the second part clutch

51

Housing bearing inner shaft

53

outer bearing moment

55

Speed sensing device

101

M_DragGBox1

102

M_DragCl1

103

M_SumInaktivUnterMotorIps1

104

M_SumInaktivÜberMotorIps1

105

M_DragGBox2

106

M_DragCl2

107

M_SumInaktivUnterMotorIps2

108

M_SumInaktivÜberMotorIps2

QUOTES INCLUDE IN THE DESCRIPTION

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

Cited patent literature

• DE 102007025253 A1 [0002]
• DE 19939818 C1 [0002]
• EP 1741950 A1 [0002]
• DE 10308517 A1 [0002]
• EP 1067008 B1 [0002]

Claims (12)

Method for monitoring a clutch, in particular a power shift clutch ( 15 . 17 . 19 ) of a drive train ( 3 ) of a motor vehicle ( 5 ), whereby the coupling ( 15 . 17 . 19 ) an engine output shaft ( 13 ) and a transmission input shaft ( 23 . 25 . 27 ) of a transmission ( 1 . 7 . 9 ) of the drive train ( 3 ), characterized by - keeping the coupling open ( 15 . 17 . 19 ) of the transmission ( 1 . 7 . 9 ), - a gear of the gearbox ( 1 . 7 . 9 ), - determining a rotational acceleration behavior of the transmission input shaft ( 23 . 25 . 27 ) of the transmission ( 1 . 7 . 9 .) Characterizing spin quantity (ω _IPS1, ω _IPS2) -.. Storing the calculated rotational acceleration variable (ω _IPS1, ω _IPS2) or a variable derived therefrom (M _{SumInaktivUnterMotorIPs1,} M _{SumInaktivÜberMotorIps1,} M _{SumInaktivUnterMotorIps2,} M _{SumInaktivÜberMotorIps2)} under allocation of a designation of the transmission. ( 1 . 7 . 9 ) and assigning the information, whether the speed of the transmission input shaft ( 23 . 25 . 27 ) of the transmission ( 1 . 7 . 9 ) greater or smaller than the speed of the motor output shaft ( 13 ) at the time of determination of the spin _amount (ω, _Ips1 , ω, _Ips2 ) in a non-volatile memory. Method according to Claim 1, characterized in that the determination of the rotational acceleration _variable (ω, _Ips1 , ω, _Ips2 ) by means of one of the transmission _{input shafts} ( 23 . 25 . 27 ) associated speed sensor device ( 55 ) he follows. Method according to one of the preceding claims, characterized in that the method in the presence of a positive and in the presence of a negative speed difference between the rotational speed of the transmission input shaft ( 23 . 25 . 27 ) of the transmission ( 1 . 7 . 9 ) and the motor output shaft ( 13 ) is performed, wherein a positive speed difference is present when the speed of the transmission input shaft ( 23 . 25 . 27 ) of the transmission ( 1 . 7 . 9 ) smaller than the speed of the motor output shaft ( 13 ) and wherein there is a negative speed difference when the speed of the transmission input shaft ( 23 . 25 . 27 ) of the transmission ( 1 . 7 . 9 ) greater than the speed of the motor output shaft ( 13 ). Method according to one of the preceding claims, characterized in that determining a rotational acceleration behavior of the transmission input shaft ( 23 . 25 . 27 ) of the transmission ( 1 . 7 . 9 ) indicative rotational acceleration _quantity (ω. _Ips1 , ω. _Ips2 ) immediately after _disengaging the gear of the transmission ( 1 . 7 . 9 ) in a period of less than 1.5 seconds, preferably within 0.5 seconds after the gear is laid out. Method according to one of the preceding claims, characterized in that the rotational acceleration _quantity (ω, _Ips1 , ω, _Ips2 ) is a speed _gradient or an angular acceleration. Method according to one of the preceding claims, characterized in that a _variable derived from the determined rotational acceleration _variable (ω, _Ips1 , ω, _Ips2 ) is a sum torque (M _{SumInactiveUnterMotorIps1} , M _{SumInactiveAberMotorIps1} , M _{SumInaktivUnterMotorIps2} , M _{SumInaktivÜberMotorIps2} ) of the transmission _input shaft ( 23 . 25 . 27 ) of the transmission ( 1 . 7 . 9 ). Method according to one of the preceding claims, characterized in that the transmission ( 1 ) a partial transmission ( 7 . 9 ) of a dual-clutch transmission with two partial transmissions ( 7 . 9 ) and two transmission input shafts Ips1 ( 25 ) or Ips2 ( 27 ) and two partial couplings ( 17 . 19 ), whereby a drag torque (M _DragCl1 , M _DragGBox1 , M _DragCl2 , M _DragGBox2 ) is determined as a function of total torques (M _{SumInactiveUnterMotorIps1} , M _{SumInactiveAberMotorIps1} , M _{SumInactiveUnterMotorIps2} , M _{SumInactiveAberMotorIps2} ), whereby a drag-side drag torque (M _DragCl1 , M _DragCl2 ) at a transmission input shaft Ips1 ( 25 ) or Ips2 ( 27 ) is determined by the following formula: M _DragCl1 = (M _{SumInactiveUnterMotorIps1} - M _{SumInactiveUberMotorIps1} ) / 2 M _DragCl2 = (M _{SumInactiveUnterMotorIps2} - M _{SumInactiveUberMotorIps2} ) / 2 and / or wherein a transmission-side drag torque (M _DragGBox1 , M _DragGBox2 ) on a transmission input shaft Ips1 ( 25 ) or Ips2 ( 27 ) is determined by the following formula M _DragGBox1 = - (M _{SumInactiveUnterMotorIps1} + M _{SumInactiveUberMotorIps1} ) / 2 or M _DragGBox2 = (M _{SumInactiveUnterMotorIps2} + M _{SumInactiveUberMotorIps2} ) / 2 where the partial coupling ( 17 . 19 ) of the partial transmission ( 7 . 9 ) which the other transmission input shaft Ips1 ( 25 ) or Ips2 ( 27 ), where M _{SumInaktivUnterMotorIps1} the summation torque at the transmission input shaft Ips1 ( 25 ) and according to the formula ω. _Ips1 J _Ips1 = M _{SumInaktivUnterMotorIps1 is} determined, this value _being determined from the stored value of the rotational acceleration _variable (ω. _Ips1 ) with assignment of the transmission ( 7 ) with the transmission input shaft Ips1 ( 25 ) and with assignment of the information that the rotational speed of the transmission input shaft Ips1 ( 25 ) of the transmission ( 7 ) smaller than the speed of the motor output shaft ( 13 ) at the time of Determining the rotational acceleration _variable ( _ω.Ips1 ) is determined, where M _{SumInaktivÜberMotorIps1} the summation torque at the transmission input shaft Ips1 ( 25 ) and according to the formula ω. _Ips1 J _Ips1 = M _{SumInaktivÜberMotorIps1 is} determined, whereby this value is determined from the stored value of the rotational acceleration _quantity (ω. _Ips1 ) with assignment of the transmission ( 7 ) with the transmission input shaft Ips1 ( 25 ) and with assignment of the information that the rotational speed of the transmission input shaft Ips1 ( 25 ) of the transmission ( 7 ) greater than the speed of the motor output shaft ( 13 ) at the time of determination of the rotational acceleration _quantity (ω. _Ips1 ), where M _{SumInactiveUnterMotorIps2 is} the summation torque at the transmission input shaft Ips2 ( FIG. 27 ) and according to the formula ω. _Ips2 J _Ips2 = M _{SumInaktivUnterMotorIps2 is} determined, this value being from the stored value of the rotational acceleration _quantity ( _ω.Ips2 ) with assignment of the transmission ( 9 ) with the transmission input shaft Ips2 ( 27 ) and with assignment of the information that the speed of the transmission input shaft Ips2 ( 27 ) of the transmission ( 9 ) smaller than the speed of the motor output shaft ( 13 ) is determined at the time of determination of the rotational acceleration _quantity ( _ω.Ips2 ), where M _{SumInaktivÜberMotorIps2 is} the summation torque at the transmission input shaft Ips2 ( FIG. 27 ) and according to the formula ω. _Ips2 J _Ips2 = M _{SumInaktivÜberMotorIps2 is} determined whereby this value from the stored value of the spin _magnitude (ω. _Ips2 ) with assignment of the transmission ( 9 ) with the transmission input shaft Ips2 ( 27 ) and with assignment of the information that the speed of the transmission input shaft Ips2 ( 27 ) of the transmission ( 9 ) smaller than the speed of the motor output shaft ( 13 ) at the time of determination of the rotational acceleration _quantity ( _ω.Ips2 ) is determined, and where J _{Ips1 is} the moment of inertia of the transmission input shaft Ips1 (FIG. 25 ) and J _Ips2 the moment of inertia of the transmission input shaft Ips2 ( 27 ) designated. Method according to one of the preceding claims, characterized in that instead of storing the rotational acceleration variable determined (ω. _IPS1, ω. _IPS2) or a variable derived therefrom (M _{SumInaktivUnterMotorIps1,} M _{SumInaktivÜberMotorIps1,} M _{SumInaktivUnterMotorIps2,} M _{SumInaktivÜberMotorIps2)} before storing weighting the determined rotational acceleration _variable (ω. _Ips1 , ω. _Ips2 ) or a variable derived therefrom with the previously stored value, wherein the weighting preferably with a weighting factor of 9/10 or 1/2 for the already stored value and 1/10 or 1 / 2 takes place for the determined not yet stored value and then the weighted value is stored, so that a smoothing of the value is present. Method according to one of the preceding claims, characterized in that the determination of the coupling-side drag torque (M _DragCl1 , M _DragCl2 ) and / or the transmission-side drag torque (M _DragGBox1 , M _DragGBox2 ) during a neutral _{phase of} the transmission ( 1 . 7 . 9 ) he follows. Method according to one of the preceding claims, characterized in that the method for different gear changes of the transmission ( 1 . 7 . 9 ) is performed several times, in particular in different directions. Method according to one of the preceding claims, characterized in that a threshold value for the coupling-side drag torque (M _DragCl1 , M _DragCl2 ) is provided and when the threshold value is exceeded by the amount of the clutch-side drag torque is detected on the presence of a drag torque at the respective clutch, wherein the Threshold is preferably 1 NewtonMeter. Transmission ( 1 ), in particular dual-clutch transmission, set up, designed and / or constructed for carrying out a method according to one of the preceding claims.

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