DE102004043541A1 - Method for control of clutch release device entails correction of desired clutch torque by control method depending upon driving situation - Google Patents

Abstract

The method for the control of a clutch release device entails sensing the position of a manually operated clutch pedal (12) and transmitting it as an electrical signal to a clutch control unit (13) which through another electrical control wire (10) operated an actuator (9) which operates the clutch (14). A desired clutch torque is corrected by the control method depending upon the driving situation. The clutch movement is determined during the build up of the clutch torque. An independent claim is included for a release device for the operating of a clutch, especially a clutch in the drive train of a motor vehicle between an engine (15) and transmission (16), has a clutch control unit with electrical sensors to register the driving state of the vehicle.

Description

The The present invention relates to a method for controlling a declutching for operation a clutch, in particular a clutch in the drive train of a Motor vehicle between the drive motor and transmission, comprising a Actuator for actuation the clutch, a clutch pedal position transmitter, which the position a manually operated Detects clutch pedal and passes as an electrical signal to a clutch control unit, which over another electric control line controls the actuator and a declutching for operation a clutch, in particular a clutch in the drive train of a Motor vehicle between drive motor and manual transmission, comprising an actuator for actuation the clutch, a clutch pedal position transmitter, which the position a manually operated Detects clutch pedal and passes as an electrical signal to a clutch control unit, which over another electrical control line drives the actuator.

For transmission the position information between a clutch pedal in one Vehicle and a release device There are besides known systems such as a mechanical transmission, for example by means of linkage or a hydraulic transmission recently called "clutch by wire "systems, at those from an electric clutch pedal position transmitter a signal transmitted to a control unit which in turn, by means of an actuator, is the release system directly mechanically or for example via a hydraulic transmission path controls. Previously known such systems form the functionality of the known hydraulic or mechanical solutions after. Disadvantageous such solutions is that they do not support the driver.

Of the The present invention is therefore based on the problem, a method for controlling a release device and a release device to provide that the driver of the motor vehicle in different Driving situations possible largely support. This problem is solved by a method according to claim 1 and a Device according to claim 14 solved.

at the method according to the invention for controlling a release device is provided that a clutch torque request from the controller dependent is corrected by a driving situation. The desired clutch torque is transmitted from the clutch to the transmission input Moment, the driver according to the position chosen by him would like to bring about the clutch pedal. Under Driving situation here are different driving conditions of the vehicle, for example starting, Up or down, stopping, cornering, emergency braking, Approaching or stopping on the mountain and the like understood. The driving situations are each characterized by speeds, accelerations, Load moments on the clutch, selected Grades, delay through the service brake and the like parameters of a motor vehicle. Accordingly, measured values go into the determination of the driving situation different sensors of different modules of a Vehicle, in particular measured values of engine management, of the chassis and the transmission control.

In a development of the method according to the invention is provided, that the gradient of the clutch travel when building the clutch torque is limited. The gradient of the clutch travel is the speed with which the clutch is closed, hence the derivative the clutch path after the time. With this limitation becomes Too strong jerky moment buildup on the part of the clutch on the Transmission prevented. This build-up of moments would otherwise be clear express noticeable jerk.

In a development of the method according to the invention is provided, if the clutch is actuated when the shift intent is detected, even if the driver does not actuate the clutch. Since in a "clutch by wire" system, the clutch torque request the driver usually over the clutch pedal is detected, there is no possibility for the controller to recognize if the driver is actually makes a gear change or not. It is in many situations useful if the controller can see that the Fairer intends to change the gear or recognize which gear the driver has currently engaged. These are a Gangerkennungssensorik and a Schaltabsichtsensorik provided that the currently inserted Gear and the driver's intention to shift. With Help of these sensors can recognize the controller, whether and which Gear or neutral position is engaged, whether the driver switch would like to and what kind of circuit the driver performs, so an upshift or a downshift.

In a development of the invention, it is provided that the desired torque of the clutch is coordinated with a calculated alternative. The calculated alternative is an optimal clutch desired torque calculated on the basis of the overall vehicle condition and thus the driving situation, which corresponds to an optimum clutch travel diert. The desired by the driver via the pedal clutch torque is therefore corrected by the controller in geeigne ter way depending on the driving situation. Regardless of the circuit type of the transmission while a Gradientbegrenzung in the construction of the clutch torque is useful, for example, when the driver slips off the pedal. Likewise, an automatic actuation of the clutch is provided when switching when the driver accidentally when switching the clutch is not actuated and a shift intention has been detected.

In a development of the method is provided that the clutch when engaged first gear and non-actuated clutch so closed is that a small moment is delivered to the transmission. In order to a so-called creep function is realized, which is a maneuvering of the vehicle without accelerator pedal (accelerator pedal) and without pressing the clutch pedal allows. After inserting a gear, for example, the first, second or reverse, without clutch pedal operation closed the clutch up to a creeping moment. The moment structure can be ramped respectively. However, if the driver has pressed the pedal, it will be done by the driver desired clutch torque set. actuated the driver depresses the clutch pedal after the gear has been engaged, as long as the creep of creep control is held until the torque request from the driver is smaller than that of the creep control. One more way to activate the creep can be achieved by implementing a detent be achieved in the clutch pedal. For example, at a Clutch pedal travel greater 95 of the Maximalweges the clutch generally be completely open. In a clutch pedal path between 90 to 95% of the maximum clutch travel can creep be on, with a clutch pedal travel less than 90% the maximum travel is the clutch torque or the clutch travel a function of the clutch pedal travel. Furthermore, in this clutch pedal travel range a pilot control of the engine happen. The pilot control of the engine can also happen if no creep is desired and if a shunting has been recognized. This means that when the idle control switch is on, pickled gear, non-operated brake and a clutch pedal travel less than 95%, so the clutch should be easily closed, the feedforward control of the engine activated is adjusted or the parameters of the idle controller become.

In a development of the method is provided that the clutch cyclically complete is closed. With this measure should be achieved that in a hydraulically actuated release system a volume compensation, a so-called sniffing is effected. Depending on used release system a volume compensation must be carried out cyclically. Depending on the used Clutch is either completely closed when the line is depressurised or completely open. If the coupling is completely closed (SAC) when the line is depressurised, then can the snoop hole open become. Is the sniffing hole open, so no slip control can be performed. Another disadvantage consists in the modulability. If the driver presses the clutch pedal, d. H. The clutch should be opened It will take some time for the sniffer hole to run over is. This deadtime can be annoying Act. To eliminate this disadvantage it makes sense to use the clutch while complete close, but the snoop hole still to keep closed. In this case, the clutch must be for volume compensation cyclically complete getting closed. If the coupling is completely open when the line is depressurised (LAC), so can the sniffer bore always open when the vehicle is with the clutch engaged. in principle could the sniffing hole also when opening the clutch are opened at a circuit to inflate To avoid the route but must overrun the sniffer bore slowly be so that the domes while a circuit would not be fast enough.

In a development of the method is provided that overloaded Clutch or almost overloaded Clutch a warning signal is generated. The warning signal can, for example be displayed as an acoustic or optical signal. The warning signal becomes too high coupling temperature or in slip situations especially when starting triggered.

In a development of the method according to the invention is provided, that the clutch is closed as far as a stop on a slope, that rolling backwards of the vehicle without operation the service brake is prevented. This driving situation, also known as "stopping on the mountain" runs on it In addition, a holding torque is applied by means of the coupling, which prevents movement of the vehicle. A start is independent of the operation the clutch, for example, then triggered when actuated the clutch Driver's request torque is increased by reducing the clutch travel or for example the accelerator pedal is actuated.

In a further development of the method it is provided that the closing of the clutch is prevented when the internal combustion engine is thereby over-turned. This is an overspeed protection for the engine. An overspeed can be triggered, for example, in an inadmissible downshift when, for example, in the time engaged gear already a high engine speed is achieved and still a smaller gear is engaged, so that an even higher speed would have to be achieved by the engine. In this case, engagement is prevented until the vehicle speed has dropped to an acceptable level.

In a development of the method according to the invention is provided, that at an over-temperature or incorrect operation a bucking by opening and closing the Clutch and / or by driving the engine control is moved. By a fluctuating drive torque at the output, either by Shut down and open the clutch or just by an active control of the engine, Thus, by more or less accelerating, achieved is the driver a faulty operation or an overtemperature of the coupling system signals. Independent of acoustic or other optical Receives warning devices the driver an immediate by the changing acceleration moments feedback of the vehicle over an undesirable or even inadmissible Operating condition of the vehicle.

In a development of the method according to the invention is provided, that the coupling is not closed further or is opened, as soon as too low a speed of the internal combustion engine sticks or starting the vehicle occurs. This is one Anti-swelling protection for the combustion engine, because an internal combustion engine is not below an idle speed can be operated. If the engine speed drops below a threshold from, for example, idle speed - 100 revolutions per minute, so The clutch must not be closed any further, to prevent the clutch from stalling To avoid motor. The threshold idle speed - 100 can possibly still a motor speed gradient dependent share elevated will stall around sure to avoid. Furthermore, it can be provided that the Clutch is opened during a full braking of the vehicle. The clutch is opened as long as the full braking carried out is or not deviating from a vehicle holding desired moment the driver by operation the clutch pedal or the accelerator pedal is displayed. Driver of Manual transmission vehicles normally occur during emergency braking Instinctively the clutch, so that the vehicle is not strangled. To be enough Having dynamic reserves can be done with opening even before kicking the clutch can be started. The clutch becomes active during a Anti-lock braking system (ABS) opened independently from the driver's desired clutch torque. A transition to the clutch request torque the driver only takes place as soon as the ABS system is deakiv again. It is possible, too, wait a while until the clutch torque request considered by the driver becomes. The clutch remains after the automatic opening as long open, until the driver presses the clutch pedal or another gear to maneuver.

In a development of the method according to the invention is provided, that the clutch upon activation of a traction control system and / or Driving stability system is closed. In an active traction control system or at activity of driving stability systems Like TCS, ESP, ASR and the like, it is not beneficial to the clutch to open. Therefore, the clutch is activated by the clutch control unit active traction control or driving stability system activity closed and remains closed, regardless of the clutch torque request the driver.

The The problem mentioned at the outset is also caused by a release mechanism for operation a clutch, in particular a clutch in the drive train of a Motor vehicle between drive motor and manual transmission, comprising an actuator for actuation the clutch, a clutch pedal position transmitter which the position a manually operated Detects clutch pedal and passes as an electrical signal to a clutch control unit, which over another electric control line activates the actuator, solved.

following is an embodiment of Invention with reference to the accompanying drawings. Showing:

1 a schematic diagram of a drive train of a motor vehicle

1 shows a schematic diagram of a drive train 1 a motor vehicle. Shown is a four-wheeled vehicle, in which a drive motor 16 via a clutch 14 and a manual transmission 15 and a drive shaft 2 about a differential 3 an axis 4 with wheels arranged therein 5 drives. The illustrated powertrain 1 is in principle identical in a vehicle with front-wheel drive and rear-wheel drive, only the arrangement of the manual transmission changes 15 and downstream drive means. Likewise, the illustrated principle can be applied to a four-wheel drive vehicle. The coupling 14 is through a release bearing 6 that with a release device 7 , For example, a release lever 8, a hydraulic or mechanical Zentralausrücker or the like is actuated. The release device is powered by an electrically operated actuator 9 actuated. The actor 9 can be directly mechanically with the release device 7 be connected or initially connected to a hydraulic master cylinder, which is connected via a hydraulic line to a slave cylinder. The actor 9 is via an electrical control line 10 with a clutch pedal position transmitter 11 connected, which the position of a manually operable clutch pedal 12 detected and as an electrical signal to a clutch control unit 13 forwards, which via another electrical control line 10 the actor 9 Ansteu ert. In addition to the clutch control unit further parameters are passed, such. As the currently engaged gear, the next preselected gear in a dual-clutch transmission, driving speed, engine speed and the like.

In an automated clutch system such as the "clutch by wire" driver continues to press the clutch pedal 12 , the pedal position of the clutch pedal 12 is from the clutch control unit 13 processed and controls the coupling in a suitable manner. In order to facilitate the driver switching, starting, clinging and maneuvering, an embodiment is shown below how the clutch control came to prevent uncomfortable situations. When the driving stability system is active, the driver is further assisted by suitable control of dynamic elements of the chassis in the control of the vehicle. Here, a solution is given below how the clutch control can intervene to avoid critical situations or to help dominate. The clutch torque desired by the driver via the pedal is provided by the controller in the form of the clutch control unit 13 Corrected appropriately depending on the driving situation. A correction takes place for example during engagement and disengagement during a thrust upshift, during engagement and disengagement during a push downshift, during engagement and disengagement during an upshift as well as during engagement and disengagement during a train downshift.

The Maneuvering without accelerator pedal (accelerator pedal) should also be done without pressing the Clutch pedals enabled become. This is after inserting a gear (1, 2 or R) without Clutch pedal operation closed the clutch up to a creeping moment. The moment structure can be ramped respectively. When the driver has pressed the pedal, the clutch torque desired by the driver becomes set. actuated the driver depresses the clutch pedal after the gear has been engaged, as long as the creep of the creep control is held until the Torque request from the driver is smaller than that of the creep control. Another way of Creep can be achieved by implementing a detent in the clutch pedal path be achieved. A detent, for example, when almost fully actuated clutch, the clutch pedal travel is greater than 95%, in this case the clutch is fully opened. At a clutch pedal travel from 90 to 95%, the creep is triggered, with a clutch pedal travel less than 90% becomes the clutch torque or the clutch travel controlled as a function of the clutch pedal travel. In this area Furthermore, a pilot control of the engine can happen. The feedforward control The engine can also be done if no creep is desired and maneuvering with idle control switch = 1 is detected. So if the idle switch = 1, a gear engaged, the brake is not applied is and the clutch pedal travel is less than 95% (the clutch should be easily closed), the feedforward control is activated or adjusted the parameters of the idle controller. At the Start with high load is it for the average driver often difficult to get the engine in one Great To operate speed and torque range without the clutch too to warm up strongly. When detecting a journey with a high load or an approach on the mountain the controller will control the clutch torque in a suitable form adjust so that the internal combustion engine in a favorable Speed and torque works, so that a comfortable journey is possible and the clutch is not overheated. The driver's desired clutch torque has lower priority in this case. When stopping with the brake the clutch must be opened a stall of the internal combustion engine. This usually happens by the driver pressing the clutch pedal. Forgets the driver activity or pressed he the clutch too late, so the clutch control can independently open the clutch a stall of the internal combustion engine. The clutch will stay that way open, until the driver makes a gear change or via the clutch pedal Request clutch torque. The transition from open Clutch to the requested clutch request torque can be the simplest Fall ramped but other transitional forms are also conceivable. If the engine speed drops below a threshold of, for example (Idling speed - 100), so the clutch must not be closed further by a kill to avoid the engine. The threshold (idling speed - 100) can possibly still a motor speed gradient-dependent share elevated will stall around sure to avoid. In an active traction control system (ASR, TCS and the like), it is not advantageous to open the clutch. Therefore the clutch is activated by the clutch control unit when activating an active Traction control is closed and remains closed, regardless of the Clutch torque request of the driver. The clutch stays so also closed when the driver actively activates the clutch after switching it on of the traction control system. The same function is performed when ESP is active.

There at the "clutch by wire "system detects the clutch torque request of the driver via the clutch pedal is there for the controller no way to recognize if the driver is actually makes a gear change or not. It is in many situations useful if the controller can detect that the driver intends to To change gear or recognize which gear the Driver has currently engaged. The use of a gear recognition sensor and shift intent sensor is used to the currently inserted To recognize the gear and the shift intention of the driver. With the help of this Sensors can tell the controller if and which gear is engaged is or whether the neutral position is inserted, the sensor can continue to recognize whether the driver wants to perform a shift and what kind of circuit the driver performs; Upshift or one Downshift. It is due to the gear recognition sensor and shift intention sensor possible, a correction of the clutch torque in the shade, starting and Maneuvering. This allows the driver to be supported depending on the situation when coupling. The driver over the pedal desired Clutch torque is controlled by the controller appropriately depending on Driving situation corrected. For all circuits, a gradient limit may be used be useful when building the clutch torque, for example when the driver slips off the pedal. The clutch is automatically activated when the clutch is inadvertently not actuated when switching by the driver and a switching intent is detected. There is also a Coordination of driver clutch torque and a calculated Alternative to the clutch control.

The Clutch becomes active of an anti-lock braking system (ABS) opened regardless of the desired clutch torque the driver. A transition The driver's desired clutch torque does not occur until the ABS system is deactivated again. It is also possible to wait a while until the clutch torque request of the driver is taken into account. The coupling remains after automatic opening open as long as until the driver presses the clutch pedal or another gear to maneuver. The clutch becomes active when driving stability systems such as closed TCS and ESP, regardless of the desired clutch torque the driver. A transition to the driver's desired torque of the clutch occurs only when the driving stability systems are deactivated again. It is also possible here, the clutch torque requirement of the driver only after expiry of a delay time to take into account.

There it at a "clutch by wire "system can give a slip control is the knowledge of the clutch characteristic, the clutch torque on the Actuator way, important. To know this, must be above the clutch temperature the coupling life is carried out an adaptation. Furthermore, that is Current clutch torque required to go through a model's current To be able to calculate clutch temperature. For these reasons offers it is, at a "clutch by wire "system store a clutch characteristic.

In a second characteristic is the relationship clutch pedal to Coupling path shown. The separation of these two characteristics has the Advantage that the characteristics of the clutch pedal regardless of the hardware, which is a function of temperature, mileage and the like can be tuned.

The Transmission speed is calculated from the wheel speed. This is one Aisle sensors required to determine the engaged gear. The transmission or the slip speed is among other things for the following Functions required: the temperature model of the clutch, one Detection of the shadow, engagement on starting and shifting, a synchronous detection, the recognition of conditions for the volume compensation as well as an overspeed protection.

If the following conditions are met, a journey through the entire system is detected:
the idle switch is not actuated.
a gear is engaged
the clutch pedal is released (at the beginning the pedal is fully depressed)
the transmission speed gradient is positive (at the beginning the speed is zero)
the transmission speed is less than a limit (eg limit = idle speed + 200)
there is a slip.

A circuit is detected by the system if the following conditions are met:
the clutch pedal is fully activated
the gait is neutral
the transmission speed is higher than a limit (eg limit = idling speed + 200)
After switching, the system remains active as long as there is a slip

1

powertrain

2

drive shaft

3

differential

4

axis

5

bikes

6

release bearing

7

declutching

8th

release lever

9

actuator

10

electrical control line

11

Clutch pedal position sensor

12

clutch pedal

13

Clutch control unit

14

clutch

15

manual transmission

16

drive motor

Claims (14)

Method for controlling a disengaging device for actuating a clutch ( 14 ), in particular a clutch in the drive train ( 1 ) of a motor vehicle between drive motor ( 16 ) and manual transmission ( 15 ), comprising an actuator ( 9 ) for actuating the clutch ( 14 ), a clutch pedal position transmitter ( 11 ) which determines the position of a manually operable clutch pedal ( 12 ) and as an electrical signal to a clutch control unit ( 13 ), which via another electrical control line ( 10 ) the actuator ( 9 ), characterized in that a clutch desired torque is corrected by the controller depending on a driving situation. Method according to the preceding claim, characterized characterized in that the gradient of the clutch travel in construction of the clutch torque is limited. Method according to one of the preceding claims, characterized characterized in that when detected switching intent, the clutch is actuated, also if the driver does not actuate the clutch. Method according to one of the preceding claims, characterized characterized in that the clutch desired torque with a calculated Alternative is coordinated. Method according to one of the preceding claims, characterized in that the clutch is engaged with first gear and not activated Clutch is closed so that a small moment to the Transmission is delivered. Method according to one of the preceding claims, characterized characterized in that the clutch cyclically completely closed becomes. Method according to one of the preceding claims, characterized characterized in that overloaded Clutch or almost overloaded Clutch a warning signal is generated. Method according to one of the preceding claims, characterized characterized in that the clutch at a stop on a slope as far as it is concluded that rolling back the vehicle without activity the service brake is prevented. Method according to one of the preceding claims, characterized characterized in that closing The clutch is prevented when it overrun the engine becomes. Method according to one of the preceding claims, characterized characterized in that at overtemperature or incorrect operation a bucking by opening and closing the Clutch and / or by controlling the engine control is effected. Method according to one of the preceding claims, characterized characterized in that the coupling is not closed further or opened is when a too low speed of the internal combustion engine Stopping or starting the vehicle occurs. Method according to one of the preceding claims, characterized characterized in that the clutch during a full braking of the vehicle is opened. Method according to one of the preceding claims, characterized characterized in that the clutch upon activation of a traction control system and / or Driving stability system is closed. Release device for actuating a clutch ( 14 ), in particular a clutch in the drive train ( 1 ) of a motor vehicle between drive motor ( 16 ) and manual transmission ( 15 ), comprising an actuator ( 9 ) for actuating the clutch ( 14 ), a clutch pedal position transmitter ( 11 ) which determines the position of a manually operable clutch pedal ( 12 ) and as an electrical signal to a clutch control unit ( 13 ), which via another a electrical control line ( 10 ) drives the actuator, characterized in that the clutch control device ( 13 ) is connected to electrical sensors for determining the driving condition of the motor vehicle.