DE102013104747A1 - Method and control device for adapting a characteristic curve of a separating clutch provided between an internal combustion engine and an electric motor - Google Patents

Abstract

According to the invention, a method for adapting a characteristic curve of a separating clutch 14 provided between an internal combustion engine 12 and an electric motor 18 is provided, in which the separating clutch 14 is initially opened while the internal combustion engine 12 is switched off and the electric motor 18 is switched on, the electric motor 18 being used for torque transmission a transmission clutch 20 is coupled to a motor vehicle transmission 22, subsequently the transmission clutch 20 is put into a slip operation and the currently acting torque of the transmission clutch 20 is determined, the separating clutch 14 is put into a slip operation, the torque given by the electric motor 18 and the dynamic torque of the electric motor 18 is determined, the dynamic torque of the electric motor 18 being determined from a current change in the angular velocity and the moment of inertia of the electric motor 18 determined by measuring the current speed of the electric motor 18 is calculated, the actual currently acting torque of the separating clutch 14 is calculated and subsequently, with the aid of the actually currently acting torque of the separating clutch 14, a corresponding target value for the separating clutch 14 stored in the characteristic curve is corrected.

Description

The invention relates to a method and a control device, with the aid of which an adaptation of a characteristic curve of a separating clutch provided between an internal combustion engine and an electric motor can be carried out.

Out DE 10 2008 042 685 A1 It is known with the aid of an electric motor to start an internal combustion engine of a hybrid motor vehicle. For this purpose, a separating clutch provided between the internal combustion engine and the electric motor is initially closed in a slipping manner, so that the rotational speed of the electric motor changes. In order to adapt a changing characteristic curve of the separating clutch ("adaptation"), a speed change of the electric motor to be expected at a later time is calculated on the basis of a characteristic value for the applied torque of the separating clutch and compared with an actual rotational speed change in order to obtain a Estimate the adjustment of the nominal value of the characteristic curve.

There is a constant need to simplify the adaptation of the characteristic curve of a separating clutch between the internal combustion engine and the electric motor of a hybrid motor vehicle.

It is the object of the invention to show measures that allow a simple adaptation of the characteristic of a separating clutch between an internal combustion engine and an electric motor of a hybrid motor vehicle.

The object is achieved by a method with the features of claim 1 and a control device with the features of claim 10. Preferred embodiments of the invention are set forth in the dependent claims, each of which individually or in combination may constitute an aspect of the invention.

According to the invention, a method is provided for adapting a characteristic curve of a disconnect clutch provided between an internal combustion engine and an electric motor, in which the disconnect clutch is initially opened, while the internal combustion engine is switched off and the electric motor is switched on, the electric motor being coupled to a motor vehicle transmission for transmitting torque via a transmission clutch , Subsequently, the transmission clutch is set in a slip operation and the current engaging torque M _{GK of} the transmission clutch is determined, the separating clutch is set in a slip operation, wherein the output of the electric motor torque M _EM and the dynamic torque M _{EMdyn of} the electric motor is determined, the dynamic moment M _{EMdyn of} the electric motor from a current change in the angular velocity ω determined by measuring the current rotational speed n _{EM of} the electric motor. and the mass moment of inertia J of the electric motor is calculated, the actual actual torque M _{TKreal of} the disconnect clutch is calculated taking into account the torque M _EM output by the electric motor, the dynamic torque M _{EMdyn of} the electric motor and the actual torque M _{GK of} the transmission clutch, and subsequently with assistance of the actual torque M _{TKreal of} the _separating clutch which is hiterlegter corresponding setpoint value M _{TKsoll is corrected} for the _separating clutch.

In particular, it is possible to determine all values required for the calculation of M _TKreal at a specific synchronized time point by measurement and / or calculation on the basis of measurements, so that it is not necessary to determine required values by extrapolation into the future. The accuracy of the adaptation of the characteristic curve can thereby be improved. Furthermore, it is considered that the characteristic curve of the friction clutch is usually stored as a combination of a heated setpoint value M _TKsoll as a function of a travel s of the separating clutch, so that the specific synchronized time for the respective measurement are assigned to a specific travel s of the separating clutch can, without an intermediate change of the travel s can affect the accuracy of the adaptation.

The actual _{instantaneous} torque M _{TKreal of} the _separating clutch can in particular be calculated directly in accordance with M _TKreal = M _EM -M _EMdyn -M _GK , without it being necessary to first convert a result of calculations into M _TKreal using an optionally not always precise conversion factor in order to carry out a comparison of M _TKreal with the nominal value M _{TKsetpoint of} the characteristic curve assigned to this operating point of the _separating clutch for the adaptation of the characteristic curve. The dynamic torque M _{EMdyn of} the electric motor can be calculated in particular according to M _EMdyn = ω .J, where ω. from the rotational speed n _{EM of} the electric motor can be determined according to ω. = ω. (n _EM ).

The value M _GK can be determined in any case, in particular in a clutch control unit for the transmission clutch, and provided, for example, via a CAN bus as information. The moment M _{EM of} the electric motor can be determined in particular via the electrical power consumption and / or is predetermined by the driver of the hybrid motor vehicle.

Furthermore, rounding inaccuracies when using a conversion factor are avoided. In particular, it is possible a setpoint M _TKsoll the characteristic curve with the directly calculated value of the actual current attacking torque M _TKreal the _separating clutch to overwrite and / or to use as a wide interpolation point of a sectionally defined by means of support points characteristic curve. In this case, if appropriate, the value of M _{TKsoll which is closest} to the value of M _TKreal used as the new interpolation point can be deleted, so that the number of interpolation points for the mapping of the characteristic curve can remain constant. The direct calculation of the actual torque M _{TKreal of} the disconnect clutch with currently measurable values allows, with increased accuracy, a simple adaptation of the characteristic curve of a disconnect clutch between an internal combustion engine and an electric motor of a hybrid motor vehicle.

By adapting the characteristic of the separating clutch, a change in the characteristic, for example due to temperature fluctuations and / or wear, can be tracked. This allows a particularly accurate control of the separating clutch, whereby a coupling of the internal combustion engine with the electric motor can be particularly gentle and comfortable. In particular, a sudden torque input into the transmission clutch and / or into the motor vehicle transmission can be avoided when closing the separating clutch. The electric motor is configured in particular as an electric machine, which can optionally be operated in the engine mode, in the generator mode and / or substantially without load. The motor vehicle transmission is in particular an automatic transmission. The transmission clutch can be designed as a friction clutch, for example multi-plate clutch and / or double clutch, or as a hydrodynamic converter. The separating clutch is designed in particular as a friction clutch, which in particular has at least one pressure plate which can be displaced relative to a counter plate, wherein in particular a travel s for displacing the pressure plate is measured in order to be able to identify different operating points of the separating clutch.

In particular, several setpoint values M _{TKsoll are stored} as a function of a travel distance s of the separating clutch in the characteristic curve, wherein in particular the contact point is stored in the characteristic curve, wherein the travel s of the separating clutch is determined at least after reaching the slip operation of the separating clutch. Via the travel s of the separating clutch, the individual operating points of the _separating clutch can be identified and a meaningful comparison of M _TKreal with M _{TKsoll can} be ensured. At the touch point takes place at a closing of the separating clutch for the first time a contact of the sides to be coupled of the separating clutch and defines the beginning of the slip operation of the separating clutch. From the touch point on the attacking moment of the clutch is greater than zero. The touch point can be identified particularly easily. The touch point can be used in particular as a reference variable for the characteristic, whereby automatically the effect of wear of friction linings can be taken into account.

Preferably, the transmission clutch is designed as a hydrodynamic converter with a lock-up clutch, wherein designed in the slip operation of the transmission clutch configured as a friction clutch lock-up clutch is operated in the slip mode and both the current torque of the hydrodynamic converter and the currently acting moment M _{LC of} the lockup clutch is determined. By the lock-up clutch torque losses can be avoided by the hydrodynamic converter in the closed state of the transmission clutch. In slip mode, the torque of the transmission clutch can be determined by M _GK = M _W + M _LC .

After a start of the internal combustion engine, the correction of the setpoint value M _TKsoll , which is boosted in the characteristic curve, is ended particularly preferably. After starting the internal combustion engine, a torque generated by the internal combustion engine would also be introduced into the separating clutch. By timely completion of the adaptation of the characteristic curve is avoided and to consider the torque input of the internal combustion engine. Instead, the separating clutch can be completely closed as soon as possible, so that efficiency losses and / or wear of the separating clutch are avoided when the internal combustion engine.

In particular, to measure the actual change in the angular velocity ω. the course of the rotational speed n _{EM of} an output shaft of the electric motor is measured, in which case in particular the two last measured values of the rotational speed n _{EM of} the output shaft which are temporally spaced apart over a sampling period are used. The speed n _EM can be measured with a tachometer easily, quickly and with a high scanning speed. For example, to determine ω. two temporally subsequent measurements of the speed n _{EM of} the electric motor at the times t ₁ and t ₂ are used, so that ω. = ω. (n _{EM, t1} , n _{EM, t2} ) holds. For example, ω. by ω. = 2π2 _{(EM n, t1} - _{EM n, t2)} / (n _{EM, EM t1} + _{n, t2)} are calculated.

Preferably, the actual actual attacking torque M _{TKreal of} the _separating clutch is compared with the corresponding nominal value M _TKsoll for the _separating clutch hiterlegt in the characteristic and it is carried out at a sufficient deviation .DELTA.M of the actual current attacking torque M _TKreal the _separating clutch of the in the curve hiterlegten corresponding target value M _TkSoll the correction of the hiterlegten in the characteristic curve corresponding target value M _TkSoll, in particular is in the characteristic curve corresponding setpoint M _TkSoll hiterlegte by the actual current engaging torque M of the clutch _TKreal replaced. A correction of the characteristic curve is thus carried out only with a sufficient deviation, which is preferably significantly greater than deviations due to expected inaccuracies in measurement. Unnecessary correction effort in the adaptation of the characteristic can be avoided.

For a specific operating point of the _separating clutch, it is particularly preferable to determine a plurality of actual _momentarily acting torques M _{TKreal of} the _separating clutch, wherein an average value of the plurality of actual acting moments M _{TKreal is} used for the correction of the corresponding nominal value M _{TKsoll hiterlegen} in the characteristic, wherein in particular the first determined value for M _TKreal and the last determined value for M _TKreal for the determination of the mean value to be discarded. If the first and the last value M _TKreal , which was determined during the controlled operating point of the _separating clutch kept constant for the determination of the several actual acting moments M _TKreal , are discarded, inaccuracies, for example due to transient boundary conditions, for example transient phenomena, can be avoided. The accuracy of the calculation of M _TKreal can thereby be increased.

In particular, until the start of the internal combustion engine for several operating point of the separating clutch, the actual momentary torque M _{TKreal of} the _separating clutch is determined and the corresponding rated value M _TKsoll for the _separating clutch, which is raised in the characteristic curve, is corrected. This makes it possible to check several points of the characteristic until the start of the engine and correct if necessary. The accuracy of the adaptation of the characteristic can be done over a larger operating range of the separating clutch.

Preferably, the actual actual acting torque M _{TKreal of} the disconnect clutch for the touch point of the disconnect clutch is determined and the characteristic parallel offset by a difference between the actual torque M M _{TKreal of} the disconnect clutch and the corresponding setpoint M _TKsoll for the disconnect clutch Actual actual acting moment M _{TKreal of} the disconnect clutch for the touch point of the disconnect clutch is the first detected actual acting moment M _{TKreal of} the disconnect clutch after the start of the slip operation of the transmission clutch. An intermediate change of the travel s of the separating clutch by wear of friction linings and / or an intermediate adjustment of the required travel s of the separating clutch by an adjusting device can be easily taken into account. A complete correction of the characteristic over the entire operating range can be avoided.

The invention further relates to a control device for adapting a characteristic of a separating clutch provided between an internal combustion engine and an electric motor, wherein the control device is adapted for carrying out the method which is characterized and further developed as described above. The control device is connected in particular, preferably via a CAN bus, to at least one corresponding measuring device and / or at least one further control device, in particular a clutch control device for the transmission clutch, in order to obtain values for M _GK , M _W , M _LC , M _EM , M _EMdyn , n _EM , ω., M _TKset ΔM, and / or s. The control _device has, in particular, an arithmetic unit in order to be able to calculate M _TKreal from the read-in data and in particular to be able to output it via an output port in order to be able to adapt the characteristic curve. The direct calculation of the actual torque M _{TKreal of} the disconnect clutch with currently measurable values allows, with increased accuracy, a simple adaptation of the characteristic curve of a disconnect clutch between an internal combustion engine and an electric motor of a hybrid motor vehicle.

The invention will now be described by way of example with reference to the accompanying drawings with reference to preferred embodiments, wherein the features shown below, both individually and in combination may represent an aspect of the invention. Show it:

1 : A schematic diagram of a powertrain of a hybrid motor vehicle and

2 : a schematic representation of the powertrain of 1 occurring torques.

The in 1 illustrated powertrain 10 a hybrid motor vehicle has an internal combustion engine 12 on, which has a disconnect clutch 14 with an output shaft 16 an electric motor 18 can be connected. The output shaft 16 can via a gearbox clutch 20 with a motor vehicle transmission designed in particular as an automatic transmission 22 be coupled. The motor vehicle transmission 22 can via a differential gear 24 with drive wheels 26 be connected.

As in 2 shown, the electric motor 18 in the drive train 10 a moment M _EM initiating a dynamic moment M _{EMdyn of} the electric motor 18 counteracts by ω .J. likewise, the moment M _EM acts on a moment M _{GK of} the transmission clutch 20 contrary, which in the case that the transmission clutch 20 is formed by a hydrodynamic converter with lock-up clutch, composed by the moment M _{W of} the hydrodynamic converter and the torque M _{LC of} the lock-up clutch. From these moments can then on the clutch 14 Actually acting moment M _TKreal determined and used with a stored characteristic curve for correction and adaptation of the characteristic curve.

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 102008042685 A1 [0002]

Claims (10)

Method for adapting a characteristic curve between a combustion engine ( 12 ) and an electric motor ( 18 ) provided separating clutch ( 14 ), in which first the separating clutch ( 14 ) while the internal combustion engine ( 12 ) and the electric motor ( 18 ) is switched on, wherein the electric motor ( 18 ) for torque transmission via a transmission clutch ( 20 ) with a motor vehicle transmission ( 22 ), hereinafter the transmission clutch ( 20 ) in a slip operation and the currently acting moment M _{GK of} the transmission clutch ( 20 ), the separating clutch ( 14 ) is placed in a slip operation, wherein the of the electric motor ( 18 ) delivered torque M _EM and the dynamic torque M _{EMdyn of} the electric motor ( 18 ), wherein the dynamic moment M _{EMdyn of} the electric motor ( 18 ) from a by measuring the current speed n _{EM of} the electric motor ( 18 ) determined current change in the angular velocity ω. and the moment of inertia J of the electric motor ( 18 ), the actual actual torque M _{TKreal of} the disconnect clutch ( 14 ) taking into account that of the electric motor ( 18 ) delivered torque M _EM , the dynamic torque M _{EMdyn of} the electric motor ( 18 ) and the current torque M _{GK of} the transmission clutch ( 20 ) is calculated and subsequently with the aid of the actual actual attacking torque M _TKreal the _separating clutch ( 14 ) a rated value M _TKsoll for the disconnect clutch (hiterlegter in the characteristic) ( 14 ) is corrected. Method according to Claim 1, in which a plurality of setpoint values M _TKsoll in dependence on a control path s of the separating clutch ( 14 ) are deposited, wherein in particular the touch point is stored in the characteristic curve, wherein the travel s of the separating clutch ( 14 ) at least after reaching the slip operation of the separating clutch ( 14 ) is determined. Method according to Claim 1 or 2, in which the transmission clutch ( 20 ) is designed as a hydrodynamic converter with a lock-up clutch, wherein in the slip operation of the transmission clutch ( 20 ) operated as a friction clutch lock-up clutch is operated in the slip mode and both the current torque of the M _{W of} the hydrodynamic converter and the currently acting moment M _{LC of} the lock-up clutch is determined. Method according to one of claims 1 to 3, wherein after a starting of the internal combustion engine ( 12 ) the correction of the setpoint value M _{TKsoll heated} in the characteristic curve is ended. Method according to one of claims 1 to 4, wherein for measuring the actual change of the angular velocity ω. the course of the speed n _{EM of} an output shaft ( 16 ) of the electric motor ( 18 In particular, the two measured values of the rotational speed n _{EM of} the output shaft (FIG. 16 ) be used. Method according to one of Claims 1 to 5, in which the actual _{instantaneous} torque M _{TKreal of} the _separating clutch ( 14 ) with the corresponding desired value M _TKsoll for the _separating clutch (in the characteristic curve) ( 14 ) is compared and at a sufficient deviation .DELTA.M of the actual actual attacking torque M _TKreal the _separating clutch ( 14 ) of the corresponding setpoint value M _{TKsetpoint ramped up} in the characteristic, the correction of the corresponding setpoint value M _TKsetpoint in the characteristic curve takes place, in particular the corresponding desired setpoint value M _{TKsetpoint hided} by the actual torque M _{TKreal of} the _separating clutch ( 14 ) is replaced. Method according to one of claims 1 to 6, wherein for a certain operating point of the separating clutch ( 14 ) a plurality of actual actual attacking moments M _TKreal the _separating clutch ( 14 ), wherein an average value of the plurality of actual _momentary attacking moments M _{TKreal is} used for the correction of the corresponding setpoint value M _{TKsoll fied} in the characteristic curve, wherein in particular the first determined value for M _TKreal and the last determined value for M _TKreal for the determination of the mean. Method according to one of claims 1 to 7, in which until the start of the internal combustion engine ( 12 ) for several operating point of the separating clutch ( 14 ) the actual moment M _{TKreal of} the disconnect clutch ( 14 ) and the corresponding nominal value M _TKsoll for the _separating clutch ( 14 ) is corrected. Method according to one of Claims 1 to 8, in which the actual _{instantaneous} torque M _{TKreal of} the _separating clutch ( 14 ) for the touch point of the separating clutch ( 14 ) is determined and the characteristic curve by a difference of the actual actual torque M _TKreal the _separating clutch ( 14 ) to the corresponding nominal value M _TKsoll for the _separating clutch, _heaped in the characteristic curve ( 14 ) is _{shifted in} parallel, wherein in particular the actual moment of _engagement M _{TKreal of} the _separating clutch ( 14 ) for the touch point of the separating clutch ( 14 ) the first determined actual moment of _engagement M _{TKreal of} the _separating clutch ( 14 ) to Start of slip operation of the transmission clutch ( 20 ). Control device for adapting a characteristic curve between a combustion engine ( 12 ) and an electric motor ( 18 ) provided separating coupling, wherein the control device is prepared for carrying out the method according to one of claims 1 to 9.

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