WO2013079044A2

WO2013079044A2 - Method for controlling a friction clutch

Info

Publication number: WO2013079044A2
Application number: PCT/DE2012/001066
Authority: WO
Inventors: Bruno MÜLLER
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2011-12-01
Filing date: 2012-11-07
Publication date: 2013-06-06
Also published as: WO2013079044A3

Abstract

The invention relates to a method for controlling a friction clutch in a drive train in a motor vehicle, comprising a clutch actuator that adjusts a clutch torque to be transmitted by means of the friction clutch, a control device by which a clutch torque to be transmitted is determined from a driver's wish and identification data of the motor vehicle and is converted into a control variable for controlling the clutch actuator, and an apparatus for detecting and damping juddering vibrations of the friction clutch by superimposing a correction function on the control variable. In order to be able to effectively damp juddering vibrations in the event of real-time problems of the clutch control, a time progression of the juddering vibrations is observed over a specified first time period up to a specified time, and for a second time period that goes beyond said time a correction function is predicted and is superimposed on the control variable during the second time period. The invention also relates to a method and to a device for controlling a friction clutch in a drive train in a motor vehicle, comprising a clutch actuator that adjusts a clutch torque to be transmitted by means of the friction clutch, a control device by which a clutch torque to be transmitted is determined from a driver's wish and identification data of the motor vehicle and is converted into a control variable for controlling the clutch actuator, a bus system effectively arranged between the clutch actuator and the control device for transmitting the control variable, and an apparatus for detecting and damping juddering vibrations of the friction clutch. In order to be able to design the clutch actuator in a simple manner, the correction functions in the control device are determined and transmitted to the clutch actuator by means of the bus system and a reference signal representing a phase position of the juddering vibrations via a separate data line between the control device and the clutch actuator. The invention also relates to a method and to a device for controlling a friction clutch in a drive train in a motor vehicle, comprising a clutch actuator that adjusts a clutch torque to be transmitted by means of the friction clutch, a control device by which a clutch torque to be transmitted is determined from a driver's wish and identification data of the motor vehicle and is converted into a control variable for controlling the clutch actuator, a bus system effectively arranged between the clutch actuator and the control device for transmitting the control variable, and an apparatus for detecting and damping juddering vibrations of the friction clutch, wherein a correction function for compensation for the juddering vibrations in the control device is determined and is transmitted via a bus system to the clutch actuator. In order to achieve a phase-selective performance of the compensation for the juddering vibrations, timers provided in the control device and in the clutch actuator are synchronised by means of at least one synchronising signal available to the control device and to the clutch actuator and the correction variable is applied in a predetermined phase position of the clutch actuator provided by the timer.

Description

Method for controlling a friction clutch

The invention relates to a method for controlling a friction clutch in a

Drive train in a motor vehicle with a coupling plate adjusting a clutch torque to be transmitted via the friction clutch, a control unit determining the clutch torque to be transmitted from a driver request and characteristic data of the motor vehicle converting into a control variable for controlling the clutch actuator, a device for detecting and damping chattering vibrations of the friction clutch, by superimposing a correction function on the control variable.

Automated friction clutches are actuated by means of a clutch actuator, which is controlled for example by means of a manipulated variable, which is determined by a control unit depending on the driving situation of the motor vehicle. The driving situation itself is predetermined by the driver and / or a corresponding automated control of the motor vehicle, for example an automated transmission with corresponding gear changes, a speed controller and the like. By Kuppiungssteller a transferable via the friction clutch clutch torque is set, which is predetermined for example via an adjustment of the friction clutch from Kuppiungssteller.

Due to a sensitivity of the drive train to vibrations, in particular torsional vibrations, changing to be transmitted clutch torque, especially during startup and switching operations and due to the frictional properties of the friction linings, geometric variations such as misalignment of the friction clutch, axial offset between the crankshaft and transmission input shaft, unevenness between engine and Transmission housing, the clutch actuator, the clutch disc and the like so-called chattering can occur, so that the friction clutch cyclically changes the slip speed, ie a differential speed between the crankshaft and transmission input shaft. Such chattering vibrations are high-frequency compared with the usual setting processes for setting the clutch torque, so that high demands are placed on the clock rate of the control of the clutch actuator and the determination of the parameters of the chattering vibrations, such as phase and frequency. From DE 10 2007 006 803 A1 a method and a device for reducing juddering vibrations in a drive train of a motor vehicle is known. In this case, a control variable in real time from a model of

CONFIRMATION COPY Obtained clutch actuator, corrected with a correction value of the real clutch actuator and made a weighting of the control variable.

Particularly in the case of a plurality of clutch actuators operated by a central control unit, for example in a dual-clutch transmission, it has proven advantageous to use a bus system, for example a CAN bus, between the clutch actuators and the control unit in order to transmit the control variables and correction variables from the control unit to the individual clutch actuators , It has been shown that the transmission rate as well as the reliability of the clock rate is dependent on bus system utilization and prioritization of the data transfer. This has the consequence that a transmission of the correction signal is time indifferent, so that an application of the correction signal can not be performed in the required accuracy of the phase position of the juddering vibrations, so that the damping effect is ineffective or the juddering vibrations are even amplified.

The object of the invention is the advantageous development of a method for controlling a friction clutch with an improved reduction of juddering vibrations.

The object is achieved by a method for controlling a friction clutch in a drive train in a motor vehicle having a clutch actuator adjusting a clutch torque that is to be transmitted via the friction clutch, a control unit that converts the clutch torque to be transmitted from a driver request and characteristic data of the motor vehicle into a control variable for controlling the clutch actuator , a device for detecting and damping frictional vibrations of the friction clutch by the control variable is superimposed on a correction function, solved, wherein a time course of the juddering vibrations over a predetermined first period is observed up to a predetermined time and for a beyond this time second period a Correction function predicates and is superimposed during the second period of the control variable. The correction function can be a sine function consisting of amplitude and frequency, but also any other function, which will be cyclically superimposed on the manipulated variable. The compensation function is transmitted to the clutch actuator via the existing bus system (CAN bus). For a given function, such as a sine waveform, the correction function can be transferred directly to the LCU. Alternatively, it may be sufficient to transmit the correction function indirectly via a transmission of frequency and amplitude thereof and the sine function in the clutch actuator to be calculated. Furthermore, the compensation function can be transmitted in the form of several data points, for example correction value and time.

The correction function is determined according to the inventive idea from previously determined signal information such as actual values of the drive train, such as high-resolution speed information of the clutch input such as engine speed and clutch output as speed of the transmission input shaft. As a result of the determination of these data and determination of the predicted correction function, subsequent superimposition of the control variable with the predicted correction function, the method for eliminating the juddering oscillations is simplified, since the determination of the correction function can be determined essentially real-time independently. As a result, control devices, sensors and data transmission lines can be made simpler. In particular, a communication bus such as a CAN bus between the clutch divider and the control unit for transmitting the control variable may be provided in the separated from the controller coupling divider, although its clock rate depending on utilization and transmission capacity does not allow real-time transmission of the control variable and in particular the phase-critical correction function. In this case, the control variable is output depending on the desired, to be transmitted via the friction clutch clutch torque correspondingly and with less dynamics and modulated the correction function for eliminating or reducing the juddering vibrations.

According to an advantageous embodiment of the method, during the first time period at least one frequency and one phase of the juddering vibrations can be determined. For example, can be determined by the waveform of the transmitted clutch torque by detecting and evaluating a differential speed and the like over a wavelength, the quality and quantity of Rupfschwingung and a corresponding correction function for the next or one of the next amplitude of Jupschwingungen phase-selectively calculated and via a data line such as Can bus be issued to the clutch plate. When evaluating a plurality of temporally successive amplitudes in the first time period, a tendency such as a change in the amplitudes, frequency and thus phase position or the like can optionally be determined, so that the predicted correction function can be determined with even higher resolution.

Advantageously, the first period is at least in the range of a cycle time of

Selected coupling device, for example, detection signals over one or more Rere clocks of the control of the clutch actuator determined by means of the control variable and, for example, for a next or after the second clock of the control of the clutch actuator determines the correction values and output with the control variable.

The prediction of the predicted correction function takes place cyclically when the juddering vibrations are detected until it decays. A routine for calculating the correction function depending on characteristic magnitudes of the juddering vibrations is hereby started and terminated depending on input and output thresholds, for example the amplitudes of the juddering oscillations, in order to avoid overcompensation and the like at very low amplitudes and to propose a robust system. These thresholds may be dependent on other parameters such as clutch temperature, mileage, type of control process, for example, when starting, switching and the like. The correction function can be obtained from sensor variables such as rotational speeds of the crankshaft and the transmission input shaft, system parameters such as the dynamics of the clutch actuator, performance data of the internal combustion engine and the friction clutch and can be calculated by taking these quantities into account. The correction function advantageously corresponds in magnitude to the predicted interference variable superimposed on the control variable, or is proportional to this with empirically or computationally determined proportionality or weighting factors and is subtracted from the control variable accordingly.

It has also proved to be advantageous if, depending on time-related delays between a signal detection of variables based on the correction quantities and application of the correction function on the coupling divider, a delay interval is estimated and a phase of the correction function is corrected with the delay interval. For example, delays in the signal detection and / or transmission, for example, rotational characteristics of a speed sensor, rotational characteristics of the internal combustion engine and the like, computing time for determining the correction function, transmission times of the correction function, hysteresis of the clutch actuator and / or the like can be estimated. The phase of the correction function is then corrected with the delay interval determined in this way, for example by the correction function being transmitted to the clutch actuator already before a predicted time, so that corresponding time delays can be corrected with a corresponding shifted phase. The invention also relates to a method and a device for controlling a

Friction clutch in a drive train in a motor vehicle with a coupling plate to be transmitted via the friction clutch clutch actuator, a the torque to be transmitted clutch torque from a driver's request and characteristics of the motor vehicle in a control variable to control the clutch actuator converting control unit, between a clutch actuator and control unit for transmitting the Control size effectively arranged bus system, a device for detecting and damping of juddering vibrations of the friction clutch.

Automated friction clutches are actuated by means of a clutch actuator, which is controlled for example by means of a manipulated variable, which is determined by a control unit depending on the driving situation of the motor vehicle. The driving situation itself is predetermined by the driver and / or a corresponding automated control of the motor vehicle, for example an automated transmission with corresponding gear changes, a speed controller and the like. By the clutch actuator a transferable via the friction clutch clutch torque is set, which is predetermined for example via an adjustment of the friction clutch from the clutch actuator.

Due to a sensitivity of the drive train to vibrations, in particular torsional vibrations, changing to be transmitted clutch torque, especially during startup and switching operations and due to the frictional properties of the friction linings, geometric variations such as misalignment of the friction clutch, axial offset between the crankshaft and transmission input shaft, unevenness between engine and Transmission housing, the clutch actuator, the clutch disc and the like so-called chattering can occur, so that the friction clutch cyclically changes the slip speed, ie a differential speed between the crankshaft and transmission input shaft. Such chattering vibrations are high-frequency compared with the usual setting processes for setting the clutch torque, so that high demands are placed on the clock rate of the control of the clutch actuator and the determination of the parameters of the chattering vibrations, such as phase and frequency.

From DE 10 2007 006 803 A1 a method and a device for reducing juddering vibrations in a drive train of a motor vehicle is known. In this case, a control variable is obtained from a model of the clutch actuator in real time, with a correspondence Correction value of the real clutch actuator corrected and made a weighting of the control variable.

The object of the invention is therefore to improve the reliability and accuracy of the application of the correction signal while maintaining a bus system for transmitting control and controlled variables from the controller to a coupling divider.

The object is achieved by a method for controlling a friction clutch in a drive train in a motor vehicle having a clutch actuator adjusting a clutch torque that is to be transmitted via the friction clutch, a control unit that converts the clutch torque to be transmitted from a driver request and characteristic data of the motor vehicle into a control variable for controlling the clutch actuator , a bus system operatively arranged between the clutch actuator and the control unit for transmitting the control variable, a device for detecting and damping chattering of the friction clutch, wherein a correction function for compensating the chattering vibrations is determined, the correction function characterizing data from the control unit via the bus system and a phase position The reference signal representing the juddering vibrations is transmitted via a separate data line between the control unit and the clutch actuator to the clutch actuator become. The correction function can be a sine function consisting of amplitude and frequency, but also any other function, which will be cyclically superimposed on the manipulated variable.

The method is particularly suitable for dual-clutch transmission, in which the

Friction clutches of a double clutch of one clutch actuator (LCU, Local Control Unit) are controlled with a local electronics for implementing a control variable and control of an electric motor. These LCUs are controlled by the central control unit (TCU, Transmission Control Unit), in which the control variable of detected sensor signals and maps, for example, the engine torque, rotational speeds of the crankshaft, the transmission input shaft, the modeled or detected clutch temperature and the like is determined. The sensor data can be detected directly by the TCU or, for example, transmitted via CAN bus from other control devices, such as a master control unit. In addition to the determination of the control variable for setting a desired transferable via the friction clutch clutch torque is detected in the TCU, if and to what extent Rupfschwingungen present. In this case, from sensor data such as a high-resolution differential speed determination of the speeds of the crankshaft and the transmission input shaft at least phase position, frequency and amplitude of Rupfschwingungen determined and determines a correction function, which is also transmitted via CAN bus to the affected LCU, by appropriate control of the electric motor causes a compensation of the juddering vibrations. The transmission of the control variables to the individual LCUs preferably takes place via CAN bus. In this case, signal transmission via the CAN bus to compensate for juddering vibrations is generally too slow, too low-frequency, and not possible in real time. When the correction quantity to be transmitted by the TCU is actually sent and received depends on the utilization of the CAN bus and the priorities of the data transmission.

In the proposed method, therefore, the control unit is provided with sufficient computing power and includes the detection of the juddering vibrations and a device such as software for compensating juddering vibrations, in which the compensation function is determined with phasing for the clutch actuator. The compensation function is transmitted to the clutch actuator via the existing bus system (CAN bus). For a given function, such as a sine waveform, the correction function can be transferred directly to the LCU. Alternatively, it may be sufficient to transmit the correction function indirectly via a transmission of frequency and amplitude thereof and to calculate the sine function in the clutch actuator. Furthermore, the compensation function can be transmitted in the form of several data points, for example correction value and time. In order that the correction function stored directly or indirectly in the LCU can be modulated onto the manipulated variable in a cyclic and in-phase manner, a reference signal in real time, for example a digital signal in the form of a switching level or an analog signal, for example a pulse width modulated signal, is transmitted via the data line transferred from the controller to the LCU, which has a constant phase or a has constant time offset to a characteristic location of the detected vibration. For example, a positive level can be applied to a digital output of the controller and transmitted via the data line. This can be applied, for example, 30 ° after a positive zero crossing of the vibration pattern of the juddering vibrations, so that the application of the correction quantity can be applied depending on the presence of this level on the clutch plate such as LCU. As an alternative to an angle-dependent output of the level, a time-dependent output of the level may be provided at a known frequency. For example, a positive level can be applied to the data line every 12 microseconds after a positive zero crossing of a juddering vibration. If an analog pulse width modulation signal to be applied, this can be provided in a duty cycle of 0-100%, wherein a predetermined duty cycle each indicates a phase shift or a time offset. Alternatively, a speed signal can be generated whose frequency indicates the phase shift or the time offset of the juddering vibrations. In this case, a low computing load of the transmitting control device and of the receiving clutch actuator (s) is preferably provided. Alternatively, additional circuits can be provided on the controllers of the control unit and clutch actuators in order to reduce their computational load.

The correction function is transmitted in parallel to the reference signal transmitted via the data line via CAN bus. The reference signal defines the exact application of the correction variable transmitted via the CAN bus as triggered, so that the time of transmission of the correction variable is not time-critical. Rather, it has been shown that the correction function for a vibration amplitude is transmitted so fast that it can be applied in good time. If this is not the case, the correction quantity can be applied with sufficient accuracy to the temporally subsequent oscillation amplitude, since adjacent oscillation amplitudes are generally present in similar intensity.

In order to be able to integrate the data line in a simple manner into a device formed from the control device and the clutch actuator effectively connected to it, the data line is preferably integrated into a free plug pin of a plug-in connection which is wired to the microcontrollers of the control unit and the clutch actuator, so that more Plug connections are dispensable.

Alternatively, it has proven to be advantageous if the data line is an activation line (ENABLE line) between the control unit and the clutch actuator to the reference signal to transfer from the control unit to the clutch plate. Here, a first signal level or a first signal pattern is impressed as modulated on the activation line to activate or maintain the activated clutch actuator. For the phase-selective triggering of the correction function, a second activation level, which is distinguishable from the first activation level, or a second, corresponding activation pattern is impressed on the activation line.

It will be understood that the means for compensating chatter may be distributed in other ways across multiple controllers. For this purpose, the data line and the reference signal applied to it is correspondingly transmitted between the control units, which on the one hand determine a real-time application and on the other hand have to apply a correction variable in real time.

The object is further achieved by a device for carrying out the proposed method comprising a control unit and a clutch plate for actuating a friction clutch, a bus system between the control unit and clutch system for transmitting a control variable for controlling the friction clutch to a predetermined transmittable clutch torque and a device for compensation of the Loosening occurring friction clutch occurring, wherein the bus system are provided for transmitting a Rupfschwingungen compensating correction signal and an additional data line for triggering the correction signal. The data line is integrated here in an advantageous manner in a plug connection of clutch plate and control unit.

The invention also relates to a method and a device for controlling a

Friction clutch in a drive train in a motor vehicle with a coupling plate to be transmitted via the friction clutch clutch actuator, a the torque to be transmitted clutch torque from a driver's request and characteristics of the motor vehicle in a control variable to control the clutch actuator converting control unit, between a clutch actuator and control unit for transmitting the Control size effectively arranged bus system, a device for detecting and damping of juddering vibrations of the friction clutch

Automated friction clutches are actuated by means of a clutch actuator, which is controlled for example by means of a manipulated variable, which depends on a control unit is determined by the driving situation of the motor vehicle. The driving situation itself is predetermined by the driver and / or a corresponding automated control of the motor vehicle, for example an automated transmission with corresponding gear changes, a speed controller and the like. By the clutch actuator a transferable via the friction clutch clutch torque is set, which is predetermined for example via an adjustment of the friction clutch from the clutch actuator.

From DE 10 2007 006 803 A1 a method and a device for reducing juddering vibrations in a drive train of a motor vehicle is known. In this case, a control variable is obtained in real time from a model of the clutch actuator, corrected with a correction value of the real clutch actuator and a weighting of the control variable made.

Particularly in the case of several clutch actuators operated by a central control unit, for example in a dual-clutch transmission, it has proven advantageous to use a bus system, for example a CAN bus, between the clutch actuators and the control unit in order to transmit the control variables and correction function from the control unit to the individual clutch actuators. It has been shown that the transmission rate as well as the reliability of the clock rate is dependent on bus system utilization and prioritization of the data transfer. This has the consequence that a transmission of the correction signal is temporally indifferent, so that an application of the correction signal is not required in the required lent accuracy of the phase position of the juddering vibrations can take place, so that the damping effect is ineffective or the juddering vibrations are even amplified.

The object of the invention is therefore to improve the reliability and accuracy of the application of the correction signal while maintaining a bus system for the transmission of control and control variables from the control unit to a clutch actuator.

The object is achieved by a method for controlling a friction clutch in a

Drivetrain in a motor vehicle with a clutch via the clutch to be transmitted clutch torque adjusting clutch actuator, the one to be transmitted clutch torque from a driver's request and characteristics of the motor vehicle in a control variable to control the clutch actuator converting control, effectively arranged between the clutch actuator and control unit for transmitting the control variable Bus system, a device for detecting and damping Rupfschwingungen the friction clutch solved, wherein a correction function for compensating the juddering vibrations in the control unit is determined and transmitted via the bus system to the clutch actuator, provided in the control unit and in the clutch actuator time counter by means of at least one the control unit and synchronizing signal available to the clutch actuator and the correction function in a predetermined Phasenla provided by the time counter ge be applied from the clutch plate. The correction function can be a sine function consisting of amplitude and frequency, but also any other function, which will be cyclically superimposed on the manipulated variable. The compensation function is transmitted to the clutch actuator via the existing bus system (CAN bus). For a given function, such as a sine waveform, the correction function can be transferred directly to the LCU. Alternatively, it may be sufficient to transmit the correction function indirectly via a transmission of frequency and amplitude thereof and to calculate the sine function in the clutch actuator. Furthermore, the compensation function can be transmitted in the form of several data points, for example correction value and time. The method is particularly suitable for dual-clutch transmissions, in which the friction clutches of a dual clutch are controlled by a respective clutch actuator (LCU, Local Control Unit) with a local electronics for implementing a control variable and control of an electric motor. These LCUs are controlled by the central control unit (TCU, Transmission Control Unit), in which the control variable of detected sensor signals and maps, for example, the engine torque, rotational speeds of the crankshaft, the transmission input shaft, the modeled or detected clutch temperature and the like is determined. The sensor data can be captured directly by the TCU or For example, be transferred via CAN bus from other control devices, such as a master control unit. In addition to the determination of the control variable for setting a desired transferable via the friction clutch clutch torque is detected in the TCU, if and to what extent Rupfschwingungen present. Here, from sensor data such as a high-resolution differential speed determination of the speeds of the crankshaft and the transmission input shaft at least phase position, frequency and amplitude of the juddering determined and determined a correction function, which is also transmitted via CAN bus to the affected LCU, by appropriate control of the electric motor causes a compensation of the juddering vibrations. The transmission of the control variables to the individual LCUs preferably takes place via CAN bus. Here, the signal transmission via the CAN bus to compensate for juddering vibrations is usually too slow, too low-frequency, and not possible in real time. When the correction function to be transmitted by the TCU is actually sent and received depends on the utilization of the CAN bus and the priorities of the data transmission.

To the reliability and time-critical application of the transmitted over CAN bus

To hedge correction function, according to the inventive idea, for example, different control devices for detecting the input signals, determination and output of the correction function and the control units of the clutch actuator synchronized by means of the time counter provided in these. The synchronization of the time counter of the control units takes place by observation of the control units and the coupling divider available common sync signal. For this purpose, signals implicitly present in the motor vehicle or signals implemented separately for this purpose can be used. For example, in each control unit, the on-board voltage can be evaluated for voltage fluctuations. Voltage fluctuations of the electrical system can be voltage jumps up or down to the mean voltage and be measured by all the controllers or microcontrollers in the one or more controllers and in the one or more clutch actuators. By correspondingly temporally fast and higher than the frequency of Rupfschwingungen resolved voltage fluctuation can be provided a synchronization of the counter.

To increase the security of a synchronization, signals originating from a source can be evaluated redundantly or multiply. Alternatively or additionally, several synchronous sources can be used to synchronize the time counters and optionally weighted according to their reliability and resolution. It has proven to be has proved particularly advantageous when digital signals transmitted via digital inputs are evaluated, the level of which can switch interrupts in the microsecond range.

In the case of an evaluation of an analog signal for synchronizing the time counters, the accuracy of the synchronization depends on an observation frequency of the measured value acquisition. For example, if the resolution is 10ms, the largest time error is 10ms, which means that, for example, the 10ms correction function detected by the controller and transmitted via the CAN bus is applied too early or too late. By increasing the observation frequency, this time error can be further restricted.

According to a particularly advantageous embodiment of the method, the clutch actuator can be connected in such a way that it generates corresponding voltage fluctuations which are reliably detected by the control unit or the integrated control units. For example, can be generated by the driving of the power amplifiers voltage fluctuations of the on-board voltage, which are reliably recognized due to their pattern of the participating devices such as control units and other clutch plates. For example, by generating a plurality of successive adjusting movements with a corresponding energy consumption of the electric motors changes in a predetermined time interval can be effected and thus a voltage pattern in the on-board voltage can be generated. By specifying the time intervals, for example, at a distance between 10 to 20 ms, the resolution of the detection of the on-board voltage signal can be increased sufficiently. If, for example, a control unit detects, twice in succession, the on-board voltage which briefly breaks in through the energization of the electric motor of a clutch actuator, it can be predicted that after the first break-in at the end of the energization the second break-in is to be expected within a predetermined time, for example within 5 ms. Alternatively or additionally, when halving the time interval between two energizing processes, a control unit detects a drop in the on-board voltage in the form of a reduced on-board voltage and the increased voltage again in the subsequent measuring process, it can be deduced that the voltage dip that occurred as a result of the second lighting operation is between times is to be classified in the two measuring processes. Thereby, the resolution of the sync signal and thus the synchronization of the time counter can be substantially doubled. In order to rule out incorrect assessments of synchronizing signals, for example voltage changes caused by other consumers in the vehicle electrical system, a corresponding synchronization intention can be communicated to the affected devices via the CAN bus. Here, a synchronization can be limited to times and events in which disturbances are excluded, for example, driving situations in which a stress on the electrical system is unlikely. For this purpose, information provided by other consumers or generators on the vehicle electrical system can be evaluated via the CAN bus. Furthermore, it may be advantageous if a time counter is changed only by using a weighting, for example by a detected synchronization error is only partially compensated. A complete compensation can be done with multiple detection of the same or a similar error.

The object is further achieved by a device for carrying out the proposed method comprising a control unit and a clutch plate for actuating a friction clutch, a bus system between the control unit and clutch system for transmitting a control variable for controlling the friction clutch to a predetermined transmittable clutch torque and a device for compensation of the Loosening occurring friction clutch occurring, the bus system for transmitting a Rupfschwingungen compensating correction function and means for synchronization provided in the control unit and in the clutch actuator, the application of the correction function controlling time counters is provided.

Claims

claims

A method for controlling a friction clutch in a drive train in a motor vehicle with a clutch plate to be transmitted via the friction clutch adjusting clutch plate, a the clutch torque to be transmitted from a driver request and characteristics of the motor vehicle in a control variable to control the clutch actuator converting control device, a device for detecting and damping chattering vibrations of the friction clutch in that the control variable is superimposed on a correction function, characterized in that a temporal course of the chattering vibrations over a predetermined first period is observed up to a predetermined time and predicts a correction function for a second time period that goes beyond this time and superimposed during the second period of the control variable.

2. The method according to claim 1, characterized in that during the first period at least one frequency and one phase of the juddering vibrations are determined.

3. The method according to claim 1 or 2, characterized in that in the first period determines a changing over time amplitude of Rupfschwingungen and is taken into account in the formation of the correction function.

4. The method according to any one of claims 1 to 3, characterized in that the first period comprises at least one cycle time of the clutch actuator.

5. The method according to any one of claims 1 to 4, characterized in that the correction function in terms of the amount of a control variable superimposed predicted interference and is subtracted from the control variable.

6. The method according to any one of claims 1 to 5, characterized in that the control variable and correction function determined in a central control unit and transmitted via a bus system to the clutch plate.

7. The method according to any one of claims 1 to 6, characterized in that a cyclically repeating and one of the control variable to be superimposed correction function calculated in the control unit and transmitted via the bus system to the clutch plate.

8. The method according to any one of claims 1 to 6, characterized in that the correction function is transmitted in the form of key figures or maps.

9. Method according to claim 1, characterized in that the correction function is transmitted in the form of parameters and the correction function in the clutch actuator is determined from these parameters.

10. The method according to any one of claims 1 to 9, characterized in that is estimated depending on time-related delays between a signal detection of the correction magnitudes underlying sizes and application of the correction function on the coupling divider, a delay interval and a phase of the correction function is corrected with the delay interval.

11. A method for controlling a friction clutch in a drive train in a motor vehicle with an on the friction clutch to be transmitted clutch torque adjusting clutch divider, the one to be transmitted clutch torque from a driver's request and characteristics of the motor vehicle in a control variable to control the clutch actuator converting control, between Clutch actuator and control unit for transmitting the control variable effectively arranged bus system, a device for detecting and damping Rupfschwingungen the friction clutch, characterized in that a correction function for compensating the Rupfschwingungen is determined, the correction function characterizing data from the control unit via the bus system and a phase of the Rupfschwingungen representing reference signal via a separate data line between the control unit and clutch plate are transmitted to the clutch plate.

12. The method according to claim 11, characterized in that a digital signal is transmitted via the data line.

13. The method according to claim 11, characterized in that an analog, pulse width modulated data signal is transmitted via the data line.

14. The method according to any one of claims 11 to 13, characterized in that the reference signal is switched at a predetermined phase position of Rupfschwingungen.

15. The method according to any one of claims 11 to 14, characterized in that the reference signal is switched in real time a predetermined period of time after determining a predetermined phase position of the juddering vibrations.

16. The method according to any one of claims 11 to 15, characterized in that a cyclically repeating and one of the control variable to be superimposed correction function calculated in the control unit and over which the bus system to the clutch plate ü is transmitted.

17. The method according to any one of claims 11 to 15, characterized in that the correction function is transmitted in the form of codes or maps.

18. The method according to any one of claims 11 to 15, characterized in that the correction function is transmitted in the form of parameters and the correction function is determined in the clutch actuator from these parameters.

19. An apparatus for performing the method according to any one of claims 11 to 18, comprising a control unit and a clutch actuator for actuating a friction clutch, a bus system between the control unit and clutch system for transmitting a control variable for controlling the friction clutch to a predetermined transmittable clutch torque and a means for compensation of chattering vibrations occurring at the friction clutch, characterized in that the bus system for transmitting a Rupfschwingungen compensating correction signal and an additional data line for triggering the correction signal are provided.

20. The apparatus according to claim 19, characterized in that the data line is integrated in a plug connection of clutch actuator and control unit.

21. The apparatus according to claim 19, characterized in that a data provided between the control unit and the clutch actuator activation line for the controlled activation of the clutch actuator is provided.

22. The apparatus according to claim 21, characterized in that the correction function is modulated onto the activation line.

23. A method for controlling a friction clutch in a drive train in a motor vehicle with a on the friction clutch to be transmitted clutch torque adjusting clutch actuator, the one to be transmitted clutch torque from a driver's request and characteristics of the motor vehicle in a control variable to control the clutch actuator converting control, between Clutch actuator and control unit for transmitting the control variable effectively arranged bus system, a device for detecting and damping of chattering of the friction clutch, characterized in that a correction function for compensating the juddering determined vibrations and the control ergerät characteristic data are transmitted to the clutch actuator via the bus system, in the control unit and in the clutch actuator provided time counter synchronized by means of at least one of the control unit and the clutch actuator available sync signal and the correction function are applied in a predetermined provided by the time counter phase position of the clutch actuator.

24. The method according to claim 23, characterized in that the at least one synchronizing signal is an on-board voltage signal tested for voltage fluctuations.

25. The method according to claim 24, characterized in that are imposed by energizing the clutch actuator according to a predetermined pattern the on-board voltage signal predetermined voltage fluctuations.

26. The method according to any one of claims 23 to 25, characterized in that the at least one signal is an interrupt in a microcontroller triggering digital signal.

27. The method according to any one of claims 23 to 26, characterized in that a cyclically repeating and one of the control variable to be superimposed correction function calculated in the control unit and over which the bus system to the clutch plate ü is transmitted.

28. The method according to any one of claims 23 to 27, characterized in that the correction function is transmitted in the form of key figures or maps.

29. The method according to any one of claims 23 to 27, characterized in that the correction function is transmitted in the form of parameters and the correction function is determined in the clutch actuator from these parameters.

30. An apparatus for carrying out the method according to one of claims 23 to 29, comprising a control unit and a clutch actuator for actuating a friction clutch, a bus system between the control unit and clutch system for transmitting a control variable for controlling the friction clutch to a predetermined transmittable clutch torque and a device for the compensation of Rupfschwingungen occurring at the friction clutch, wherein the bus system for transmitting a Rupfschwingungen compensating correction function and means for synchronizing provided in the control unit and in the clutch actuator, the application of the correction function controlling time counters is provided.