DE112014002172B4 - Method for controlling mechanical power transmitted by a friction clutch device - Google Patents

Abstract

Method for controlling mechanical power (108) transmitted by a friction clutch device (102) in a motor vehicle drive train between an internal combustion engine and a transmission, wherein a hysteresis effect that occurs is compensated for using a hysteresis model (112), the hysteresis model (112) having an actuator travel and depicts an assigned engagement path, in which case, in addition to an actuator-path-coupled engagement path change (500, 508, 518, 522), an actuator-path-decoupled engagement path change (600) can be mapped, wherein to map the actuator-path-decoupled engagement path change, the engagement path is changed in a time-controlled manner without changing the actuator path, with the actuator-path-decoupled engagement path change being mapped (600) the engagement travel can be changed without changing the actuator travel, taking into account a hysteresis model error, the hysteresis model error being determined taking into account a torque balance, characterized in that the Mo ment balance is determined taking into account an internal combustion engine torque and a torque based on a characteristic curve of the clutch.

Description

The invention relates to a method for controlling a mechanical power transmitted by a friction clutch device in a motor vehicle drive train between an internal combustion engine and a transmission, a hysteresis effect that occurs being compensated with the aid of a hysteresis model.

EP 1 418 083 A2 shows a method for controlling a mechanical power transmitted by a friction clutch device in a drive train of a vehicle between an internal combustion engine and a transmission, wherein a hysteresis effect that occurs is compensated for using a hysteresis model.

DE 10 2010 012 756 A1 shows a method for adjusting clutch parameters.

From the DE 10 2011 011 152 A1 a method is known for controlling a friction clutch arranged between an internal combustion engine and a transmission by means of a clutch actuator which axially actuates an actuating element of the friction clutch along an actuating path which is assigned via a clutch characteristic to a setpoint torque which can be transmitted via the friction clutch, with a difference between the setpoint torque and the torque actually transmitted via the friction clutch Actual moment along the actuation path occurring hysteresis is compensated by correcting a target value determined for controlling the clutch actuator by means of a correction variable. Of the DE 10 2011 011 152 A1 According to this, the correction quantity is determined in a hysteresis model operated with relevant quantities of the friction clutch and the clutch actuator. The correction variable is designed in two stages depending on an actuation path.

The object of the invention is to functionally improve a method mentioned at the outset. In particular, a hysteresis model is to be functionally improved. In particular, a control of a friction clutch device should be specified. In particular, the adaptability of a clutch model is to be improved. In particular, a depiction of a real hysteresis behavior of a friction clutch device in a hysteresis model is to be improved. In particular, model errors should be reduced or avoided. In particular, an error adaptation of a software coefficient of friction should be reduced. In particular, robustness against vibration effects that cannot be precisely foreseen should be provided or increased.

The object is achieved by a method with the features according to claim 1.

The object is thus achieved with a method for controlling mechanical power transmitted by a friction clutch device in a motor vehicle drive train between an internal combustion engine and a transmission, with a hysteresis effect that occurs being compensated for using a hysteresis model, with the hysteresis model depicting an actuator travel and an associated engagement travel and wherein in addition to an actuator-path-coupled engagement path change, an actuator-path-decoupled engagement path change can be mapped.

The friction clutch device can be actuated automatically. The friction clutch device can have at least one friction clutch. The friction clutch device can have a single friction clutch. The friction clutch device can have a single clutch. The friction clutch device can have a clutch input part and a clutch output part. The friction clutch device can have two friction clutches. The friction clutch device can have a double clutch. The friction clutch device can have a clutch input part and two clutch output parts.

Starting from a fully open actuation position, in which essentially no power transmission takes place between a clutch input part and a clutch output part, to a fully closed actuation position, in which essentially complete power transmission takes place between the clutch input part and the clutch output part, a friction clutch can be controlled depending on the actuation allow increasing power transmission, with a power transmission between the clutch input part and the clutch output part takes place by friction. Conversely, starting from a completely closed actuation position, in which essentially complete power transmission takes place between a clutch input part and a clutch output part, up to a completely open actuation position, in which essentially no power transmission takes place between the clutch input part and the clutch output part, a decreasing, controllable, actuation-dependent position Power transmission can be enabled. A double clutch can be used to switch a power flow from a clutch input part in transition between a first clutch output part and a clutch output part.

A friction clutch can be a single-plate clutch. A friction clutch can be a multi-plate clutch. A friction clutch can be a dry clutch.

A friction clutch can be a wet clutch. A friction clutch can be a pressed clutch. A friction clutch can be a pulled clutch. A friction clutch may have an axis of rotation. The clutch input part can have a housing part, at least one pressure plate and at least one pressure plate. The at least one pressure plate and the housing part can be firmly connected to one another. The at least one pressure plate and the housing part can each be connected to one another in a torque-proof manner. The at least one pressure plate can be displaced to a limited extent in the axial direction relative to the at least one pressure plate between a clutch open position and a clutch closed position. A displacement of the at least one pressure plate in the direction of the clutch closed position can also be referred to as engagement. A displacement of the at least one pressure plate in the direction of the clutch opening position can also be referred to as disengagement. A clutch output part can have at least one clutch disc. The at least one clutch disc can be clamped between the at least one pressure plate and the at least one pressure plate for frictional power transmission.

The friction clutch device can have an actuating device. The actuating device can be used for the automated actuation of the friction clutch device. The actuating device can have at least one actuator. The at least one actuator can be used to move the at least one pressure plate. The at least one actuator can be controllable using at least one electrical control device.

The motor vehicle drive train can have an internal combustion engine. The motor vehicle drive train can have a torsional vibration damper, in particular a dual-mass flywheel. The motor vehicle drive train can have the friction clutch device. The motor vehicle drive train can have a transmission. The motor vehicle drive train can have at least one drivable vehicle wheel. The motor vehicle can have at least one electrical control device. The control device can be used to control the internal combustion engine, the friction clutch device and/or the transmission. The control device can be used for the automated actuation of the friction clutch device. The control device can have a number of structurally and/or functionally separate control modules. The control modules can be connected to one another in a signal-conducting manner.

The mechanical power can be controlled by controlling a torque. The mechanical power can be controlled by controlling a speed.

To control the mechanical power, a control engineering observer can be operated in parallel with a real friction clutch device. The observer may include an adaptive clutch model. The observer may include a replica of the real friction clutch device. The observer can include a controller. At least one input variable of the observer can be based on at least one input variable of the real friction clutch device. At least one additional input variable from the observer can be based on at least one measured variable of the real friction clutch device.

A hysteresis may have a clutch open leg and a clutch closed leg. The hysteresis can be influenced by mechanical friction. The hysteresis can be influenced by a setting behavior. The hysteresis model can be based on a drag indicator model. The drag pointer model can behave like a drag pointer in a slot. When the elongated hole moves, the slave pointer can be taken along if there is contact with an edge of the hole. When the direction of movement of the elongated hole changes, the trailing pointer can initially remain stationary until contact is made with an opposite edge of the hole.

According to the invention, the engagement travel is changed in a time-controlled manner without changing the actuator travel in order to map the change in engagement travel that is decoupled from the actuator travel. Timing can be done using a time parameter. The time parameter can be adjustable.

According to the invention, the engagement travel can be changed without changing the actuator travel, taking into account a hysteresis model error, in order to map the change in engagement travel that is decoupled from the actuator travel. The hysteresis model can be influenced by at least one model parameter. A model parameter may be engine torque. A model parameter can be a clutch torque. The hysteresis model error can be assigned to a responsible model parameter and this model parameter can be corrected.

According to the invention, the hysteresis model error is determined taking into account a torque balance.

According to the invention, the torque balance is determined taking into account an internal combustion engine torque and a torque based on a characteristic curve of the clutch.

When determining the torque based on a characteristic curve of a clutch, an engagement and/or disengagement range can be taken into account in which the friction clutch device does not transmit any power. A touch point can be taken into account when determining the torque based on a characteristic curve of the clutch. The characteristic curve of the clutch can have a slope. A clutch torque can be proportional to a contact pressure.

The hysteresis model error can be determined using the equation T _{K_BKM} -T _{K_KKL} = T _Fehrer . T _{K_BKM} can be a clutch torque that is determined based on an internal combustion engine torque. T _{K_KKL} can be a clutch torque that is determined based on a clutch characteristic. T _error can be a moment resulting from a hysteresis model error. The hysteresis model error can be determined using a drag pointer model and a position of the drag pointer can be a correctable model parameter.

In addition, the object on which the invention is based can be achieved with a method for determining a hysteresis in a friction clutch in a motor vehicle, the hysteresis being determined using a hysteresis model, the hysteresis model being formed by a drag pointer in a slot which has an edge The drag pointer is moved with the slot when the slot moves and at the same time when there is contact with the edge of the slot and the drag pointer can also be moved when it is not in contact with the edge of the slot. The movement of the drag pointer can be a time-controlled movement of the drag pointer into the center position of the slot when it is not in contact with the edge of the slot. The direction of movement of the drag pointer can result from a detected error in a moment balance if it is not in contact with the edge of the slot.

In summary and presented in other words, the invention thus results, among other things, in an expanded clutch hysteresis model. The extended clutch hysteresis model can be based on a hysteresis model, which essentially behaves like a drag pointer in a slot. The drag pointer can be taken through either side of the slot. The extension can provide that the slave pointer can also move when it is not in contact with an edge of the slot. The movement of the drag pointer without contact with the edge of the slot can be controlled in various ways: 1. Time-controlled movement to the center position of the slot; 2. The direction of movement of the slave pointer is determined by a model error that may have been detected in a moment balance.

In particular, “may” denotes optional features of the invention. Accordingly, there is in each case an exemplary embodiment of the invention which has the respective feature or features.

A hysteresis model is functionally improved with the method according to the invention. Control of a friction clutch device is specified. An adaptability of a clutch model is improved. A depiction of a real hysteresis behavior of a friction clutch device in a hysteresis model is improved. Model errors are reduced or avoided. An error adaptation of a software friction coefficient is reduced. A robustness against shaking effects that cannot be precisely foreseen is given or is increased.

Exemplary embodiments of the invention are described in more detail below with reference to figures. Further features and advantages result from this description. Specific features of these exemplary embodiments can represent general features of the invention. Features of these exemplary embodiments that are associated with other features can also represent individual features of the invention.

• 1 ein Diagramm zur generellen Struktur eines adaptiven Kupplungsmodells,
• 2 ein Diagramm zu einem physikalischen Brennkraftmaschinenmodell,
• 3 ein Diagramm zu einem Kupplungsmoment bei geöffneter Kupplung,
• 4 ein Diagramm zu einem Kupplungsmoment bei geschlossener Kupplung,
• 5 ein Diagramm zu einer aktuatorweggekoppelten Einrückwegänderung,
• 6 ein Diagramm zu einer aktuatorweggekoppelten Einrückwegänderung,
• 7 ein Diagramm zu einer aktuatorweggekoppelten Einrückwegänderung,
• 8 ein Diagramm zu einer aktuatorweggekoppelten Einrückwegänderung und
• 9 ein Diagramm zu einer aktuatorwegentkoppelten Einrückwegänderung.

They show schematically and by way of example:

• 1 a diagram of the general structure of an adaptive clutch model,
• 2 a diagram of a physical internal combustion engine model,
• 3 a diagram of a clutch torque with the clutch open,
• 4 a diagram of a clutch torque when the clutch is closed,
• 5 a diagram of an actuator travel-coupled engagement travel change,
• 6 a diagram of an actuator travel-coupled engagement travel change,
• 7 a diagram of an actuator travel-coupled engagement travel change,
• 8th a diagram of an actuator path-coupled engagement path change and
• 9 a diagram of an actuator path-decoupled engagement path change.

1 shows a diagram 100 for the general structure of an adaptive clutch model. A real friction clutch 102 is arranged in a motor vehicle drive train between an internal combustion engine and a transmission. The friction clutch 102 is used for the controlled opening and closing of the drive train in order to enable starting and a change of gear ratios of the transmission. The friction clutch 102 is actuated automatically using an actuator. The actuator is controlled using an electrical control device. Control engineering methods are carried out with the aid of the control device. The adaptive clutch model is used to control the actuator and thus to actuate the friction clutch 102 . The adaptive clutch model is represented using a control engineering observer 104 .

The observer 104 is arranged parallel to the friction clutch 102 . Observer 104 reconstructs a calculated clutch torque from the known clutch input torque, also referred to as internal combustion engine torque 106, and the clutch output torque, also referred to as clutch torque 108, of observed friction clutch 102. For this purpose, the observer 104 simulates the observed friction clutch 102 as a model 110 and includes a controller that tracks the real clutch torque 108 . In addition, observer 104 includes a hysteresis model 112 for correcting errors in clutch model 110 caused by hysteresis. A correction variable 118 is determined from this with the aid of the hysteresis model 112 . Correction variable 118 is supplied to clutch model 110 in addition to internal combustion engine torque 106, so that a hysteresis influence on the calculated clutch torque is adaptively taken into account.

2 shows a diagram 200 for a physical internal combustion engine model. Using the internal combustion engine model, a clutch torque T _K is determined based on an internal combustion engine torque T _BKM , an internal combustion engine speed n _BKM and an internal combustion engine work J _BKM . This clutch torque is also referred to as T _{K_BKM} .

3 shows a diagram 300 for a clutch torque 302 when the clutch is disengaged. A characteristic clutch curve 304 is shown in diagram 300 . An actuator travel is plotted on an x-axis and a clutch torque is plotted on a y-axis. The clutch torque is proportional to a pressing force of a friction clutch, such as friction clutch 102 according to 1 . The clutch characteristic curve 304 runs horizontally, starting from a completely open clutch with an increasing actuator travel, up to a touch point 306 . Touch point 306 is the point at which an increase in clutch torque begins with increasing actuator travel. In this area 308, in which the actuator position 310 is present, there is no increase in the clutch torque, even as the actuator travel increases.

4 shows a diagram 400 for a clutch torque 402 when the clutch is engaged. A characteristic clutch curve 404 is shown in diagram 400 . An actuator travel is plotted on an x-axis and a clutch torque is plotted on a y-axis. The clutch torque is proportional to a pressing force of a friction clutch, such as friction clutch 102 according to 1 . Starting from a contact point 406, the clutch characteristic curve 404 rises linearly with an increasing actuator travel with a slope a. In this area 408, in which the actuator position 410 is present, the clutch torque increases as the actuator travel increases. The actuator, shown as a model, acts on the friction clutch 414 with the interposition of a compression spring 412. As the actuator travel increases, the contact pressure of the friction clutch 414 increases and an increasing clutch torque is transmitted.

5-8 each show a diagram for an actuator travel-coupled representation of an engagement travel change in a clutch model, such as clutch model 110. In the diagrams, an actuator travel is plotted on an x-axis and a clutch torque is plotted on a y-axis. The clutch torque is proportional to a pressing force of a friction clutch, such as friction clutch 102 according to 1 . A coupling between the actuator and friction clutch, such as friction clutch 102 according to 1 , is shown as a model with the aid of a drag pointer 500, which is guided in a slot 502. The elongated hole 502 is assigned to the actuator and the drag pointer 500 is assigned to a pressure plate of the friction clutch acted upon by the actuator. In the diagram 504 the trailing pointer 500 is in contact with the right-hand edge of the slot 502. The actuator is in an actuator position 506. When elongated hole 502 moves in arrow direction b, as shown in diagram 508, drag indicator 500 is initially not driven up to actuator position 510, until drag indicator 500 rests against the left-hand edge of elongated hole 502 . This The actuator travel corresponds to a length of the elongated hole 502 and a hysteresis width 512. The actuator, shown as a model, acts on the friction clutch with the interposition of two compression springs 514, 516 arranged in series. With increasing actuator travel, the compression spring 514 is compressed, the compression spring 516 and thus the friction clutch are not yet subjected to friction. If elongated hole 502 moves further in the direction of arrow c, as shown in diagram 518, drag pointer 500 is carried along up to actuator position 520. With increasing actuator travel, compression spring 516 is also compressed, overcoming friction and thus the friction clutch applied. If slot 502 moves in the opposite direction in arrow direction d, as shown in diagram 522, trailing pointer 500 is initially not driven up to actuator position 524, until trailing pointer 500 is again in contact with the right-hand edge of slot 502. This actuator travel again corresponds to the length of the slot 502 and the hysteresis width 512. With increasing actuator travel, the compression spring 514 is relieved, the compression spring 516 not yet being relieved due to friction and the friction clutch continues to be acted upon. Only when the elongated hole 502 moves further in the direction of the arrow d is the slave pointer 500 carried along and a return to the state shown in the diagram 504 ensues.

9 shows a diagram 600 for an actuator path-decoupled representation of an engagement path change in a clutch model, such as clutch model 110. Based on the in 7 In the state shown, in which trailing pointer 500 is taken along to actuator position 520, compression spring 516 is compressed while overcoming friction and the friction clutch is loaded, an engagement path actuator can be represented in the clutch model in a path-decoupled manner, in that compression spring 516 is pressed without further actuator travel while actuator position 602 remains the same further compressed and the clutch torque 604 is increased in the direction of arrow e. A hysteresis influence, for example due to vibrations and an associated increase in contact pressure with a constant actuator position, can thus be mapped. Incidentally, in addition, in particular, reference is made to the 5-8 and the associated description.

reference list

100

diagram

102

friction clutch

104

observer

106

engine torque

108

clutch torque

110

clutch model

112

hysteresis model

114

clutch torque

116

error moment

118

correction size

200

diagram

300

diagram

302

clutch torque

304

clutch characteristic

306

tactile point

308

area

310

actuator position

400

diagram

402

clutch torque

404

clutch characteristic

406

tactile point

408

area

410

actuator position

412

compression spring

414

friction clutch

500

trailing pointer

502

Long hole

504

diagram

506

actuator position

508

diagram

510

actuator position

512

hysteresis width

514

compression spring

516

compression spring

518

diagram

520

actuator position

522

diagram

524

actuator position

600

diagram

602

actuator position

604

clutch torque

Claims (4)

Method of controlling one of a friction clutch device (102) in a force mechanical power (108) transmitted in the vehicle drive train between an internal combustion engine and a transmission, with an occurring hysteresis influence being compensated for using a hysteresis model (112), with the hysteresis model (112) mapping an actuator travel and an associated engagement travel, with in addition to an actuator travel-coupled engagement travel change (500 , 508, 518, 522) an actuator-path-decoupled engagement path change (600) can be mapped, with the engagement path being changed in a time-controlled manner to map the actuator-path-decoupled engagement path change without changing the actuator path, with the actuator-path-decoupled engagement path change (600) being mapped by the engagement path without changing the actuator path, taking into account a Hysteresis model error is changeable, the hysteresis model error is determined taking into account a moment balance, characterized in that the moment balance taking into account an internal combustion engine torque and a he clutch characteristic based torque is determined. procedure after claim 1 , characterized in that the hysteresis model error is assigned to a responsible model parameter and this model parameter is corrected. Method according to at least one of Claims 1 until 2 , characterized in that the hysteresis model error according to the equation $$T_{K\_BKM}-T_{K\_KKL}=T_{feHle\mathrm{right}}$$

is determined. Method according to at least one of Claims 1 until 2 , characterized in that the hysteresis model error is determined using a drag indicator model and a position of the drag indicator (500) is a correctable model parameter.

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