DE102007050987A1 - Drive train arrangement of a vehicle and method for controlling the operation of the same - Google Patents

Abstract

The invention relates to a drive train arrangement (10) of a vehicle and an associated method for controlling the operation thereof, comprising at least one internal combustion engine (12) and an electric machine (13) which can be coupled thereto by means of a clutch (15). It is provided that at least one coupling load point (22.1, 22.2) can be determined on the basis of a speed change of the electric machine (13).

Description

The The invention relates to a drive train arrangement of a vehicle with the features mentioned in the preamble of claim 1 on the one hand and an associated method for controlling the operation of a Drive train arrangement of a vehicle with those in the preamble of Claim 6 mentioned on the other hand.

State of the art

A drive train arrangement of a vehicle and a method for controlling the operation of a drive train arrangement of a vehicle of the type mentioned are from the published patent application DE 100 06 861 A1 known. The drive train arrangement described therein for a motor vehicle or the method disclosed therein comprises successively an internal combustion engine, a starter clutch, an electric machine, a drive clutch and an automatic transmission, preferably an automated manual transmission. It is provided that the starter clutch and the clutch is assigned a common dual clutch actuator, which allows an optional setting of the respective status, namely open or closed, the clutches by taking a corresponding switching position.

A Change in the switching position of the clutches takes place in usually during driving of the vehicle. Especially in the starter clutch or a similar device for Torque transmission between the internal combustion engine and the electric machine finds engagement or disengagement automatically instead. The automatic closing respectively automatic opening of the relevant clutch during the driving operation sets a precise knowledge of the coupling properties ahead. Otherwise, an exact control of the corresponding Clutch excluded. A not precisely controllable and thus not exactly working clutch not only leads to an early wear of the same, but Affects the entire driving in a significant Measure.

Disclosure of the invention

The Drive train arrangement according to the invention of a vehicle comprising at least one internal combustion engine and a thereto by means of a switchable coupling detachable electric machine with the features mentioned in claim 1 offers the other hand the advantage that determines accurate data and information of the coupling behavior can be, whereby only an exact control of the clutch is possible. In this case, at least one Kuppentastpunkt based a speed change of the electric machine determined become. The coupling point represents a clutch adjustment, when the clutch starts or stops, a torque transferred to. In other words, the coupling point is representative of a clutch position, which after a Clutch distance is reached and at the following this is a coupling process or a decoupling process is initiated. The dome load point thus provides a reference point for a clutch characteristic.

On Reason of the determined and thus known Kuppentastpunkts can a planned and thus gentler and more efficient Coupling process or uncoupling performed automatically become. In addition to a reduction in wear of the clutch can also improve driving comfort from the perspective of a vehicle controlling driver are obtained. Further leaves based on the data-based knowledge of the response of the clutch expresses realize agile driveline behavior. A quick connection the internal combustion engine to the electric machine or also a rapid separation of the two machines from each other is feasible with a high precision. The same applies analogously to the method of control the operation of the drive train arrangement of a vehicle with the features of claim 6.

advantageous Further developments result from the characteristics of the dependent Claims.

In An advantageous embodiment of the invention is provided that based on the speed change both the Kuppentastpunkt when opening the clutch as well as the coupling load point when closing the coupling can be determined. Based on the determined coupling points is a detection or a measurement of a clutch hysteresis possible. Under the clutch hysteresis is in this context a path difference of a clutch actuator between the two Kuppentastpunkten in approaching each other or again from each other Removing coupling plates understood. The knowledge about the course of the clutch hysteresis serves in connection with the course of the Coupling characteristic to, transition areas when opening and closing the clutch. The more accurately the clutch is measured and recorded, the more accurate can be a control of the same.

According to a preferred embodiment of the invention, it is provided that the respective Kuppentastpunkt is repeatedly determined to form an average value. As a result, measuring inaccuracies can be relativized and a reliable statement about the coupling behavior and the coupling property be made. This procedure also causes, apart from the first opening operation of a plurality of opening and closing operations of the clutch comprehensive series of measurements, in the opening operations of the clutch only a so-called sliding friction instead of static friction comes into play. A distinction is made between the static friction and the sliding friction, because a friction occurring between two bodies, in particular coupling elements or coupling plates, has different values. If the two bodies, if necessary with a contact force on each other, prevails static friction. However, if at least one of the two bodies moves, then the static friction is transferred into the sliding friction. The static friction is usually greater than the sliding friction.

In An advantageous embodiment of the invention is provided that the internal combustion engine and / or the electric Machine by means of another clutch with a transmission, in particular automated manual transmission, can be coupled. This arises with the involvement of the drivetrain section designed as a drive train arrangement clutchable transmission a comprehensive drivetrain that as such are installed in a vehicle, in particular a motor vehicle can.

According to one preferred embodiment of the invention it is provided that the electric machine with an energy storage, in particular rechargeable battery, is in operative connection. The electric Machine is on the one hand in its function as a drive unit of the battery is supplied with energy and on the other hand loads it into their function as a generator. In the latter function is the electric machine powered by the internal combustion engine.

The Advantages of the dependent arrangement claims apply in a similar way also for the characteristics of the dependent ones Method claims.

Brief description of the drawings

The Invention and advantageous embodiments according to the Features of the further claims are described below the embodiments shown in the drawings explained in more detail, without that being a restriction the invention takes place; rather, this includes all modifications, changes and equivalents that are possible under the claims are. Show it:

1 a complete drive train arrangement with a unit for transmitting torque, in particular wheel drive, and with an energy storage, in particular rechargeable battery, in a schematic representation;

2 a function diagram for detecting a first Kuppentastpunkts and a second Kuppentastpunkts based on a speed change and at constant torque of an electric machine; and

3 a further function diagram for detecting each of a plurality of values of a first Kuppentastpunkts and a second Kuppentastpunkts based on a speed change and at a constant torque of an electric machine.

Embodiment (s) of the invention

In 1 is a drive train arrangement 10 as part of a powertrain 11 shown. The drive train arrangement 10 has an internal combustion engine 12 and an electric machine 13 on, over a common drive shaft 14 by means of a coupling 15 are detachable. The electric machine 13 is still on the common drive shaft 14 with a gear 16 via an additional clutch 17 coupled. If both clutches 15 ; 17 are closed, this is also the internal combustion engine 12 with the gearbox 16 coupled. The gear 16 is preferably executable as a so-called automatic transmission that ultimately via the drive shaft 14 with a torque transmission unit 18 , in particular wheel drive, in a mechanical operative connection 19 stands. An electrical connection 20 is also between the electric machine 13 - Also called electric machine - and an energy storage 21 , in particular rechargeable battery, given.

Such a construction of the drive train 11 is referred to as a fuel / electric hybrid drive or parallel hybrid type P2, in which typically the electric machine 13 after the clutch 15 and in front of the gearbox 16 is installed. Other variants among the parallel hybrids are the P1, the P3 and the P4 hybrid. In the P1 hybrid, the electric machine sits 13 on the drive shaft 14 , in particular crankshaft, directly behind the internal combustion engine 12 that is, before the clutch 15 and the transmission 16 , The electric machine sits in the P3 hybrid 13 at one to the clutch 15 opposite end of the transmission 16 , Finally, in the P4 hybrid, the electric machine acts 13 not on the same drive shaft 14 like the internal combustion engine 12 but is arranged on a separate shaft.

The P2 configuration of the powertrain 11 allows electric driving with the electric machine 13 with the clutch open 15 , If there is an increased power requirement or the energy storage 21 is emptied too much, there is a Connection of the internal combustion engine 12 over the clutch 15 , The connection of the internal combustion engine 12 This is done while driving. To be able to precisely control this process, the behavior of the clutch must be 15 and their clutch characteristic to be known. An essential aspect here is the determination of a first coupling load point 22.1 when closing the clutch 15 and a second coupling point 22.2 when opening the clutch 15 according to the 2 and 3 ,

For the determination of the two coupling points 22.1 ; 22.2 after the 2 and 3 comes with the electric machine 13 a small measuring torque 24 given and only their speed detected. For this purpose, first the clutch 15 closed so far that associated coupling elements 15.1 ; 15.2 or coupling plates introduce a torque transmission until the first Kuppentastpunkt 22.1 certainly exceeded. Then with the electric machine 13 the measuring torque via the drive shaft 14 on the clutch 15 applied. The coupling 15 is subsequently opened slowly until the electric machine 13 starts with a certain speed 25 to turn. Then the clutch is 15 immediately closed slowly again until the speed 25 the electric machine 13 again sinks. Finally, the electric machine 13 off. Once the electric machine 13 has stalled, the clutch becomes 15 opened again. Thus, the two Kuppentastpunkte 22.1 ; 22.2 when closing or when opening the clutch 15 based on a speed change of the electric machine 13 determined.

According to 2 is a function plan 23 for detecting the first coupling point 22.1 and the second domed loadpoint 22.2 based on the speed change of the electric machine 13 and at constant torque thereof. The function plan 23 includes three flowcharts 23.1 ; 23.2 ; 23.3 of which the first flow chart 23.1 the course of the torque M _{EM of} the electric machine 13 over time t and the second flowchart 23.2 the course of the speed n _{EM of} the electric machine 13 over time t shows. The third flowchart 23.3 in addition to this, coupling paths s _{K of} the coupling 15 or whose coupling elements 15.1 ; 15.2 according to 1 or an actuator for driving the coupling elements 15.1 ; 15.2 over time t.

The sequence of a procedure for detecting respectively measuring the two coupling points 22.1 ; 22.2 in detail, it is as follows:
First, the clutch 15 over a cupola path to a dome position 22 closed so far that, taking into account all component tolerances, the measuring torque 24 not to slip on the two coupling elements 15.1 ; 15.2 according to 1 leads. Then the electric machine 13 with the measuring torque 24 applied. This does not yet lead to a rotation of the electric machine 13 because of their clutch torque or one via the clutch 15 applied contact force between the coupling elements 15.1 ; 15.2 higher than the measuring torque 24 , A so-called friction and breakaway torque of the internal combustion engine 12 In contrast, it is much higher, so that it stands still. As soon as the torque 24 the electric machine 13 has set, the clutch will 15 slowly open until the electric machine 13 starts to turn. It is sufficient, a first rotational movement 25.1 the electric machine 13 to detect. The detection of the first rotary motion 25.1 corresponds to the detection of the first domed load point 22.1 during the opening process of the clutch 15 ,

After that, the clutch 15 closed again slowly over a period of time. By a characteristic of the coupling called hysteresis 15 this does not directly lead to a higher clutch torque. The electric machine 13 is therefore slowly accelerated during the period. However, the acceleration is very low because only the moment is available as the drive torque, after deduction of an actual clutch torque from the moment of the electric machine 13 still available. Therefore, in this case also first the clutch position held and from the acceleration of the electric machine 13 a moment difference are calculated to thereby compensate for the detected touch point. This would result in a touch point upon the occurrence of an actual slip effect. The tactile point determined under the influence of a static friction could then be disregarded.

As soon as the clutch torque rises again, the speed drops 25 the electric machine 13 again. Once it is determined that the speed 25 a speed reduction 25.2 learns, so falls instead of rises, is the other Kuppentastpunkt 22.2 for the closing process of the clutch 15 found. The electric machine 13 will be turned off again afterwards. Once the electric machine 13 has reached its stoppage, the clutch is 15 opened again. Alternatively, the clutch 15 also be opened immediately, leaving the electric machine 13 runs free. It is also possible, the electric machine 13 to slow down to a standstill by a negative moment.

The measuring method allows the clutch to be applied or closed 15 without any torque present, or that the combustion force machine 12 is in operation. This prevents that with a stiff teeth of a drive plate of the clutch 15 a self-inhibition effect occurs, which is used to determine incorrect values for the first coupling load point 22.1 leads. Since the process takes place at very low speeds, the energy requirement and the load, in particular energy input, the clutch 15 very low. Furthermore, the measuring process does not depend on the stability of a (speed controller.) No waiting times are required for the speed controller to settle in. The electric machine 13 becomes only the constant torque throughout the measurement 24 specified. Due to the low speed 25 The torque required by a torque converter is almost immaterial. It is therefore not necessary to detect a torque change compared to a large basic value. This makes it possible to realize a much lower torque for a Tastpunktadaption with good accuracy. The actual hatching phase is very short. This also minimizes energy consumption and energy input.

At low speeds, electric machines often have a lower torque accuracy than at high speeds. As for the measuring method, however, a precise moment of the electric machine 13 At low speeds, an improvement in the accuracy of the moment can be made, in which the torque is measured before the actual detection method. This can be done with the clutch open 15 and stationary electric machine 13 the little moment of the electric machine 13 be controlled. Then the electric machine 13 slowly accelerated. From the very precise inertia of the electric machine 13 and an associated mass and a speed of increase of the speed 25 the actual moment can then be calculated. Faults, such as one at the additional clutch 17 Even in the open state existing friction torque, thereby avoided. This measurement must also take place at low speeds. Because the so-called repeatability of the electric machine 13 is much better than the absolute accuracy, thus resulting in a precise measurement. The measurement can, for example, at the end of the Tastpunktmessung by opening the clutch 15 be performed.

According to 3 is another function plan 26 for detecting the first coupling point 22.1 and the second domed loadpoint 22.2 based on the speed change of the electric machine 13 and at constant torque thereof. The further function plan 26 includes as well as the function plan after 2 three flowcharts 26.1 ; 26.2 ; 26.3 of which the first flow chart 26.1 the course of the torque M _{EM of} the electric machine 13 over time t and the second flowchart 26.2 the course of the speed n _{EM of} the electric machine 13 over time t shows. The third flowchart 26.3 in addition to this, coupling paths s _{K of} the coupling 15 or whose coupling elements 15.1 ; 15.2 according to 1 or an actuator for driving the coupling elements 15.1 ; 15.2 over time t.

The course of a further function plan 26 associated method for detecting or measuring the two Kuppentastpunkte 22.1 ; 22.2 in detail, this is as follows:
First, the clutch 15 over a cupola path to the dome position 22 closed so that taking into account all component tolerances, the measuring torque 24 not to slip on the two coupling elements 15.1 ; 15.2 according to 1 leads. After that, the constant torque 24 the electric machine 13 set. Then each is below a lower speed threshold 27.1 the coupling 15 slowly open until the speed 25 starts to rise again. Again, this is the first rotational movement 25.1 decisive for the first coupling point 22.1 , If an upper speed threshold 27.2 is achieved, as long as a slow closing of the clutch 15 until the speed 25 begins to fall. The speed reduction 25.2 corresponds to the second coupling point 22.2 , In this way, the speed fluctuates 25 in the manner of a two-point controller between two low speed values. This allows several measured values and thus several coupling positions for the respective coupling load point 22.1 ; 22.2 when opening or when closing the clutch 15 be detected metrologically. As a result, averaging is possible. The value recorded in each case can be corrected for each point via the speed change and the mass inertia.

In the measuring method according to 3 takes place after the first opening of the coupling 15 any further coupling opening now under the influence of sliding friction and not under the influence of static friction.

In summary, the determination of the respective coupling load points takes place in both measuring methods 22nd ; 22.2 based on the speed change, in particular based on a speed control, and constant torque 24 the electric machine 13 , so only the speed 25 the electric machine 13 must be recorded or pursued. This is an adaptation of the Kupplungstastpunkte 22.1 ; 22.2 achievable in a P2 hybrid drive. The measured values obtained in the measurement method are generally fed to a control unit which is used for signal processing, in particular processing tion of measurement signals and measurement information. The control unit in turn can together with the drive train arrangement 10 or the powertrain 11 Part of a vehicle, in particular motor vehicle be.

The measuring methods can also be used with slight limitations of the adaptation quality when the internal combustion engine is in operation and is idling. Here is the additional clutch 17 according to 1 open, so no torque to the gearbox 16 is forwarded. The Kuppentastpunkt is then determined based on a speed change of the electric machine relative to the idle speed of the internal combustion engine. A first application or closing of the clutch 15 At the beginning of the measurement process is preferably carried out at speed equality of the internal combustion engine and the electric machine, so that no torque via the clutch 15 exists or arises. This prevents self-locking effects that can lead to the determination of incorrect values for the coupling point. To set the speed equalization, the electric machine must be with the clutch open 15 and opened auxiliary coupling 17 generate a compensation torque to compensate for existing friction moments. By determining the compensation torque and a consideration or connection of the same during the determination of the Kuppentastpunktes, the measuring torque 24 be specified very precisely.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 10006861 A1 [0002]

Claims (14)

Drive train arrangement ( 10 ) of a vehicle having at least one internal combustion engine ( 12 ) and one by means of a coupling ( 15 ) detachable electric machine ( 13 ), characterized in that at least one coupling point ( 22.1 ; 22.2 ) based on a speed change of the electric machine ( 13 ) can be determined. Drive train arrangement ( 10 ) according to claim 1, characterized in that on the basis of the speed change both the Kuppentastpunkt ( 22.1 ) when opening the clutch ( 15 ) as well as the coupling point ( 22.2 ) when closing the clutch ( 15 ) can be determined. Drive train arrangement ( 10 ) according to one of the preceding claims, characterized in that the respective coupling load point ( 22.1 ; 22.2 ) can be determined several times to form an average value. Drive train arrangement ( 10 ) according to one of the preceding claims, characterized in that the internal combustion engine ( 12 ) and / or the electric machine ( 13 ) by means of an additional coupling ( 17 ) with a transmission ( 16 ), in particular automated manual transmission, can be coupled. Drive train arrangement ( 10 ) according to one of the preceding claims, characterized in that the electric machine ( 13 ) with an energy store ( 21 ), in particular rechargeable battery, is in operative connection. Method for controlling the operation of a drive train arrangement ( 10 ) of a vehicle having at least one internal combustion engine ( 12 ) and with one by means of a coupling ( 15 ) detachable electric machine ( 13 ), characterized in that at least one coupling point ( 22.1 ; 22.2 ) based on a speed change of the electric machine ( 13 ) is determined. A method according to claim 6, characterized in that based on the speed change both the Kupplungstastpunkt ( 22.1 ) when opening the clutch ( 15 ) as well as the clutch checkpoint ( 22.2 ) when closing the clutch ( 22.2 ) be determined. Method according to one of claims 6 or 7, characterized in that the respective coupling load point ( 22.1 ; 22.2 ) is repeatedly determined to form an average value. Method according to one of claims 6, 7 or 8, characterized in that the internal combustion engine ( 12 ) and / or the electric machine ( 13 ) by means of an additional coupling ( 17 ) with a transmission ( 16 ), in particular automated manual transmission, is coupled. Method according to one of claims 6 to 9, characterized in that an energy store ( 21 ), especially rechargeable battery, the electric machine ( 13 ) or by means of the electric machine ( 13 ) is recharged. Method according to one of claims 6 to 10, characterized in that the electrical machine ( 13 ) a measuring torque ( 24 ) is given. Method according to one of claims 6 to 11, characterized in that an increase in the accuracy of the measuring torque ( 24 ) is performed by a dynamic measurement. Method according to one of claims 6 to 12, characterized in that at the beginning of a measurement, a first application or closing of the clutch ( 15 ) takes place, without causing a torque via the clutch ( 15 ) acts or arises. Method according to one of claims 6 to 13, characterized in that in the determination of the at least one dome load point ( 22.1 ; 22.2 ) Acceleration and rotor inertia of the electric machine ( 13 ).