DE102007034199A1 - Process for determination or testing of a coupling position of a vehicle engine connecting rod coupling useful for incremental path measurements of a vehicle engine connecting rod coupling gives more consistent results than past processes - Google Patents

Abstract

Process for determination or testing of a coupling position of a vehicle engine connecting rod coupling automated by an Aktor (sic) using the coupling torque transferred from the coupling (sic). In the current coupling position a first transferred coupling torque is determined by a first method and a second transferred coupling torque by a second method on the basis of existing (sic) engine data. The difference between the two methods is determined so that the assumed coupling position corresponds to the true coupling position and the difference is less than a predetermined threshold limit. An independent claim is included for a device for determination or testing of a coupling position of a vehicle engine connecting rod as described above.

Description

The The present invention relates to a method for checking the Clutch position of an automatically actuated by means of an actuator clutch in Drive train of a vehicle having a drive motor means of the transmitted from the coupling Clutch torque according to the preamble of claim 1.

Out Vehicle technology is the use of an actuator for automated activity a clutch in the drive train of a vehicle known. Order now the Actuate the clutch so that it is suitable for the respective vehicle condition desired Moment transfers, is the knowledge of the coupling position required. To now the coupling position can be found on an existing on the actuator Wegmesseinrichtung resorted which is an absolute displacement measurement or an incremental displacement measurement can act. Incremental path measurement only changes position captured and the current absolute position must, starting from a known starting position, by integration of the position changes be determined.

If now in the case of an Inkrementalwegmessung example of a erroneous starting value is assumed, or the institution for determining the coupling position, which is an im Vehicle available control unit in the form of, for example, the clutch control device can calculate a faulty absolute position for the clutch actuator, such an erroneously calculated absolute position can lead to the clutch is further closed by the actuator, for example, as this is just necessary in the considered application.

So it may be desirable as an application, for example, a low clutch torque adjust the clutch in the amount of, for example, 1 to 5 Nm to slightly brace the driveline of the vehicle to rattle vibrations to prevent in the transmission. Now instead of this desired Verspannmoments due to a faulty determined absolute position of the Clutch actuated so the actuator that he continues to drive the clutch and this one higher Clutch torque transfers, so can This will lead to a Ankriechen or even start the vehicle instead only to slightly tension the drivetrain.

at It is therefore necessary to use an incremental displacement measurement that the Inkrementalwegmessung regularly checked and adjusted if necessary is, d. H. a corresponding referencing is performed. In order to carry out such an adjustment of the Inkrementalwegmessung, can a stop be groped, the position of the stop as new zero point or reference point for the adjustment of the incremental path measurement can be used.

Such an approach is for example based on the DE 44 33 825 A1 become known, which describes an adjusting device for a friction clutch of a motor vehicle and the adjusting device comprises a clutch position control. In this known method for detecting a stop signals of the actuator, such as the current, the speed, the direction of rotation and the signals of an incremental encoder are used and evaluated to detect a stop. Thus, the detection of a stop is made possible by the evaluation of actuator-internal signals of the clutch actuator.

If now this known method for referencing the coupling position is used, but the coupling position but along the Travel of the actuator determined only at two defined locations be, namely at a stop at full closed clutch and on a stop when fully open Clutch. Thus, this possibility the stop detection during a normal driving operation of the vehicle only at the described Special situations available, namely only at complete closed and at full open clutch. Does the clutch but an intermediate position, For example, a slip state, so this possibility of referencing falls the clutch position by means of stop detection already without replacement path.

Especially with dual-clutch transmissions or parallel-shift transmissions Clutch actuators used with incremental displacement measurement, the only Position changes however, can not capture absolute positions. In contrast to the procedure described above by means of the stop detection the possibility referencing or plausibility check of the coupling position in not just one particular driving situation, namely completely open or completely closed coupling, to allow There is a need for a method, the plausibility of the absolute position the clutch driving situation independent carry out to be able to.

With reference to the applicant DE 2005 009 711 A1 A method for referencing an incremental path measurement in a motion transmission between an actuator and a clutch of an automatically operated transmission in a drive train has already become known. This known method provides that a reference position of the actuator in dependence of a transmitted from the clutch Kupplungsmo is determined.

These known method therefore makes use of the clutch torque transmitted by the clutch and works without impact detection. This is the determined Clutch torque, ie the torque transmitted by the clutch, a specific Assigned coupling position and the associated coupling position corresponds to a specific position of the actuator, as the clutch through actuates the actuator is and is coupled with this. This will be a change evaluated the clutch torque during the movement of the actuator to a Determine reference position for adjusting the incremental distance measurement.

Even though this known method already a significant improvement across from the homing by means of stop detection represents owns there is still room for Improvements.

outgoing It is the object of the present invention to provide an improved procedure for checking the Clutch position of an automatically actuated by means of an actuator clutch in the drive train of a vehicle having a drive motor by means of the transmitted from the coupling To provide coupling torque.

Next this method, the invention is also a device for execution of the method.

The The invention now provides a method with regard to the method the features of claim 1 before. Advantageous embodiments of the method are described in the further claims. Furthermore the invention provides a device with regard to the device with the features of claim 12.

to solution the above-described object with regard to the method The invention now provides a method for checking the coupling position an automatically actuated by an actuator clutch in the drive train a vehicle having a drive motor by means of the transmitted the clutch Clutch torque, wherein in the presence of clutch slip on the basis of currently assumed clutch position, a first transmitted clutch torque is determined according to a first method and a second transmitted Clutch torque according to a second method based on state data of the drive motor is determined and a difference of after both Methods assigned to certain Clutch torque is determined such that the assumed clutch position the actual Coupling position corresponds, if the difference is smaller than a predeterminable Threshold is.

The The invention therefore provides a method which in clutch slip the transmitted clutch torque determined redundantly according to two different physical principles and then checked by means of a comparison of the two clutch torques, whether the determination with the two methods to a consistent Result leads. Lies such a consistent result, so is the difference the first and the second clutch torque smaller than a predeterminable threshold value, so it can be concluded that the currently accepted Coupling position of the actual current coupling position corresponds and thus from the Inkrementalwegmessung certain assumed clutch position of the actual clutch position corresponds and thus a plausibility and referencing of the Inkrementalwegmessung certain coupling position is enabled.

The Designation as the first and second clutch torque are used only the distinction of which method the transmitted Clutch torque is determined. It will be so in the case of a slipping Coupling a difference formed between the after the first method certain transmitted Clutch torque and transmitted according to the second method Clutch torque and checked if the thus formed difference is smaller than a pre-definable threshold and hence the assumed one determined from the incremental displacement measurement Clutch position actually the actual Coupling position corresponds.

There to carry out This method no stop detection is necessary, this method of the invention driving situation regardless be used and is independent of promotions, such as the touch of attacks. Thus, the plausibility and Referencing the absolute position of the coupling during the normal driving operation of the vehicle are carried out continuously and not only when the clutch is fully open or completely closed is.

To a development of the method according to the invention, it is now provided that the predeterminable threshold in dependence on the determination the difference used state data and / or the current assumed clutch position is determined. So, for example a driving situation dependent Limit can be used as pre-definable threshold, the dependent on from the engine torque, the clutch torque, the clutch position or other parameter is determined.

To a development of the invention, it is also contemplated that the first clutch torque based on a clutch torque as a function the coupling position determining relationship is determined. Here For example, a coupling model can be used or in the simple case, a relationship defined by a characteristic between the transferred Clutch torque and the clutch position. Will be a clutch model as the relationship between the clutch torque and the clutch position used, such a coupling model can also adaptation strategies include, by its transmission behavior for example, depending on is changed by the engine torque and the engine speed. Such an adaptation strategy For example, the adaptation of the coefficient of friction of the clutch or a touch point adaptation or a shape adaptation (shape adaptation) include. Thus, for example, the adaptation speed in the procedure entrance to medium and long-term changes in the behavior of the clutch to compensate.

To a development of the invention, it is provided that after the second method by means of certain second transmitted clutch torque an observer, in particular Störbeobachters, and the speed and the engine torque of the drive motor is determined. The transmitted clutch torque occurs as a non-measurable disturbance for the behavior of the drive motor up and can be appreciated as one Disturbance variable for the dynamic Behavior of the drive motor can be used.

there determines the interference observer an estimated transmitted by means of the engine torque and the engine speed Clutch torque, which is for example in a dual-clutch transmission can also be a summation moment. This so determined second Clutch torque and slipping clutch according to the first method determined first transmitted Clutch torque can then be used for subtraction and then by means of already described above, for example, driving situation-dependent threshold made a check be whether the difference thus formed is smaller than the predetermined Threshold.

is this difference is smaller than the predeterminable threshold value, then leads the Determination of the transferred Clutch torque according to both methods to a consistent result, from which it can be inferred that the currently accepted Coupling situation of the actual current coupling situation corresponds to that from the transmitted Clutch torque over For example, a clutch characteristic or an adapted clutch characteristic or the one already mentioned above Coupling model, the coupling position can be determined. In order to but can also be a new referencing by means of Inkremetalwegmessung certain absolute position of the clutch are made. Also is thus a plausibility check of the assumed clutch position possible with the determined coupling position and regardless of previously determined driving situations or coupling situations.

To In a further development of the invention, it is provided that the difference is determined in a slip condition of the clutch. Indicates a clutch Slip on, the amount of torque transmitted through them is the same the set transferable Moment of the clutch. The coupling can not transmit moment anymore because everything is what about the set transferable Torque of the clutch goes out, leading to slippage. This is the slip state the coupling a characteristic that can be incorporated in the process according to the invention.

To An alternative to this, the invention but also on the adhesion the coupling can be extended, namely in that the difference in the state of adhesion of the coupling determined becomes. Here can be closed then on a mistake, if the Amount of the transmitted clutch torque determined by the second method, that is, for example, using the above-described interference observer, that clearly exceeds the clutch torque determined by the first method, wherein, for example, temporal effects can be taken into account, since the transmitted moment to be no bigger on a coupling can be considered the currently transferable Moment, which by the determined by the first method clutch torque represents becomes.

The inventive method can, for example, as a control loop in a control unit for the control This can be implemented by the actor and here it can be after a training The invention may be advantageous if the difference to reduce the influence of parameters of the signal determination and / or the Signal processing is filtered, so filtered the torque difference is the influence of random effects, such as Measurement noise or small time shifts due to Signaling and / or signal processing to reduce.

If, in the above-described formation of the clutch torque difference, it is determined that the difference is greater than the predeterminable threshold value, an error handling device can be activated according to an embodiment of the invention. It is possible, for example, as a reac tion on a detected error - the torque difference is greater than the predeterminable threshold - to set a FehlerFlag and reduce a confidence measure for the clutch position and / or the clutch torque, as in the also attributed to the applicant DE 10 2004 021 983.4 has been described.

The inventive method can now be used, for example, an assumed Absolute position by means of an actuator with incremental displacement measurement actuated Plausibilisieren clutch in the drive train of a vehicle.

The Proposed method may further be used to monitor operability a double clutch with two so-called compressed couplings under Applying an actuating force be closed and open automatically in power-free state, used be a moment when a part of a drive train and a clutch the other clutch transmit a moment to a second part of the drive train can, with provided in the partial drive trains gears at each open clutch inserted and switching by overlapping the two clutches takes place, so that a previously loaded with moment Disabled partial drive train and the other by transferring Moment is activated. The control of such crossover circuits is technically complex and requires always predictable and reproducible behavior the couplings with respect their torque transmission. The proposed method may additionally or additionally affect the behavior of the clutches as an alternative to the previously proposed solutions, by monitoring whether one of the clutches unexpectedly transmits no torque and / or whether one of the couplings is jammed.

Transfers one Clutch unexpectedly no moment, can be a mistake in the hardware, for example, in the mechanical path between an actuator driving electric motor and engagement engaging on the clutch, causing the for the one to be transmitted Moment desired engagement path not covered and therefore the clutch is not actuated is, or completely opens in the absence of any operating force, although a corresponding displacement sensor, the kinematically before the defective Component is arranged, indicating a corresponding actuation path. hereby results in an incorrect calculation of the transmitted clutch torque by means of a characteristic in dependence from the actuation path. The proposed method is used to determine a coupling error used to the fact that at the open clutch and / or at in this partial drive train switched neutral position during the another clutch torque on the associated subtransmission transmits over a given period of an estimate, for example by means of of the observer determined moment compared with a predetermined threshold becomes. In the same way, the determined from the actuation path torque compared with a predetermined threshold. Is the estimated moment smaller and the calculated moment greater than the given one Thresholds is from a fault the actuation path go out and it is issued an error signal.

In analogously, this can be the jamming of a clutch or the associated actuator detected and a corresponding error signal are output. In In this case, the clutch no longer separates or no longer completely, while the Position sensor incorrectly a corresponding path of the actuator detected. A detection of this error situation is carried out by Check, whether an estimated moment greater than a predetermined threshold and the determined from the distance measurement Moment is less than a predetermined threshold. It also checks if there is between the crankshaft of the drive motor and the transmission input shaft the slip is below a predetermined threshold. If all fulfilled three conditions are, an error signal is output. By examining the be determined from the clutch travel moments and the slip Misinterpretations excluded, which result from that while the predetermined observation period, the clutch no slip shows, because only very small moments are transmitted.

Finally creates the invention also a device for determining or checking the Clutch position of an automatically actuated by means of an actuator clutch in the drive train of a vehicle having a drive motor by means of the transmitted from the coupling Clutch torque, the device of the above-described Method and has at least one sensor for Inkrementalwegmessung of the actuator and a control unit with a Evaluation device for Condition data of the drive motor, in particular of the engine torque and the engine speed, as well as the determination of a transmitted Clutch torque based on the clutch position and / or the condition data, in particular the engine speed and the engine torque.

This device may, for example, be a control device for the actuator for the automated actuation of the clutch or else another control device present in the vehicle. This control unit is for example via a bus system in the vehicle in the form at For example, the CAN bus, the engine torque and the engine speed supplied by the engine control and in the control unit, the above-mentioned Störbeobachter be implemented, which considers the transmitted clutch torque as an estimated disturbance variable for the dynamics of the drive motor and the transmitted clutch torque determined, which then with the For example, based on the assumed current clutch position determines a transmitted clutch torque and then forms a difference between the second, determined by the observer transmitted clutch torque and the first, based on the assumed current clutch position determined by a clutch model, which may also be implemented in the control unit Clutch torque and this difference then evaluates with respect to the question of whether it is less than the predeterminable threshold value and thus both methods have led to a consistent result and thus the currently assumed clutch position corresponds to the actual current clutch position.

The invention will be described below with reference to the 1 and 2 explained in more detail, which show a block diagram for explaining the method according to the invention and a flow chart of an embodiment of a fault determination.

1 shows in block 1 a disturbance observer, which determines an estimated quantity for the clutch torque transmitted by the clutch on the basis of state data of the drive motor in the form of the engine rotational speed nEng and the engine torque TrqEng.

On the basis of the assumed current clutch position LClutch is in block 2 the transmissible clutch torque is determined using a first method and then both results are evaluated 3 fed.

In the evaluation block 3 also enters the SlipClutch slip state of the clutch, which can be checked whether the clutch is in a slip state. In the evaluation block 3 is in the presence of clutch slip, the difference between the above-described method according to the second method in the block 1 determined transmitted clutch torque and in the block 2 made transmitted by the first method transmitted clutch torque.

is this difference is smaller than a predeterminable threshold value, then it is concluded that the assumed current clutch position the actual current coupling position corresponds. In case of error, if namely the Amount of the difference between the transferred values determined by both methods Clutch moments exceeds the predeterminable threshold, an error flag ErrorFlag is set.

In order to does the invention make it possible the current clutch position during ongoing vehicle operation constantly to plausibility and referencing and not just for example im completely open or complete closed state of the clutch.

2 shows a flowchart for checking an open clutch of a dual clutch while the other clutch transmits torque on its associated drive train. Starting from a block 4 will be in the branch 5 checked whether that according to the example in the block diagram of 1 certain moment TrgClutchMod from displacement measurement of the clutch is greater than a constant C. Furthermore, it is checked whether the torque estimated from the disturbance observer TrqClutchEst is smaller than a constant D. The constants C and D can be identical. The time counters 6 . 7 as well as the block 8th make sure that when there is no condition of branching 5 a certain amount of time is measured. If a certain expiry time t has elapsed, block 8th exit the program without further steps if no divergent condition has been found in branching. The branch 9 Ensures that in case of deviation in branching 5 is measured repeatedly for a time t corresponding to the constant E. It is understood that the control of the times and frequencies of the passage of the branch 5 can also be solved differently. Is a violation of conditions in branching 5 is stated in block 10 set an error flag ErrorFlag and depending on this in block 11 initiated, which provides an error localization and / or an error response, for example, an emergency operation of the vehicle, in which only the error-free coupling and its associated partial drive train is used. In block 12 the routine is ended. In a similar routine, the jamming of a clutch can be checked. For this purpose, if necessary, the constant C, D and E are adjusted and the expiry time t. Continues in the branch 5 a condition TrqClutchMod <C linked by the logical operation "AND" with the condition TrqClutchEST> D and the condition of a negligible slip between the crankshaft of the drive motor and the transmission input shaft of the clutch to be tested.

Regarding not closer in detail Illustrated Features of the invention will be otherwise expressly on claims and the drawings referenced.

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block

2

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3

evaluation block

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5

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6

time counter

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time counter

8th

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Claims (15)

Method for determining or checking the coupling position of a clutch automatically actuated by means of an actuator in the drive train of a vehicle having a drive motor by means of the clutch torque transmitted by the clutch, characterized in that based on the currently assumed clutch position, a first transmitted clutch torque is determined by a first method and a second transmitted clutch torque is determined according to a second method on the basis of state data of the drive motor and a difference of the transmitted torque determined by both methods is determined such that the assumed clutch position corresponds to the actual clutch position when the difference is smaller than a predeterminable threshold. Method according to claim 1, characterized in that that the predeterminable threshold value depending on the determination the difference of used state data and / or the currently assumed Coupling position is determined. Method according to claim 1 or 2, characterized that the first transmitted Clutch torque based on a clutch torque as a function of Clutch position determining relationship is determined. Method according to one of the preceding claims, characterized characterized in that the second transmitted Clutch torque by means of an observer, in particular Störbeobachters and the rotational speed and the engine torque of the drive motor determined becomes. Method according to one of the preceding claims, characterized characterized in that the difference in a slip state of Coupling is determined. Method according to one of claims 1 to 5, characterized that the difference in the adhesion state of the coupling is determined. Method according to one of claims 1 to 6, characterized that in a dual-clutch transmission the torque of a clutch to be transmitted is checked, while the other clutch is open is. Method according to claim 7, characterized in that that an error signal is output when in a predetermined Observation period determined by a model size for the transferred Moment greater than a threshold for the model and the determined transmitted moment smaller than one for the determined moment is given threshold. Method according to claim 7, characterized in that that an error signal is output when in a predetermined Observation period determined by a model size for the transferred Moment less than a threshold for the model and the detected transmitted moment greater than one for the determined moment is given threshold. Method according to one of the preceding claims, characterized characterized in that the difference to reduce the influence parameters of signal detection and / or signal processing is filtered. Method according to one of the preceding claims, characterized characterized in that the first transmitted Clutch torque dependent of state data of the drive motor, in particular the speed and the engine torque and / or adapted clutch parameters determined becomes. Method according to one of claims 4 to 8, characterized that by means of the interference observer on the basis of speed and engine torque of the drive motor the second transmitted clutch torque estimated is and the difference is formed between the first transmitted clutch torque and the esteemed second clutch torque. Method according to one of the preceding claims, characterized characterized in that at a threshold exceeding the predeterminable Difference an error handling device is activated. Use of the method according to one of the preceding claims to check the plausibility of the assumed absolute position of a an actuator with Inkrementalwegmessung actuated clutch in the drive train of a vehicle. Device for determining the coupling position an automatically actuated by an actuator clutch in the drive train a vehicle having a drive motor by means of the transmitted the clutch Clutch torque, in particular according to one of claims 1 to 11, characterized by at least one sensor for Inkrementalwegmessung of the actuator and a control unit with an evaluation device for Condition data of the drive motor, in particular the engine torque and the engine speed and the determination of a transmitted clutch torque based on the coupling position and / or the state data, in particular the engine speed and the engine torque.