DE102010053944A1 - Method for operating clutch system of motor vehicle, involves reducing control energy absorption of actuators during closing of clutch, if control energy amount exceeds critical control energy amount for actuators - Google Patents

Abstract

The method involves reducing the control energy absorption of the actuators during closing of a clutch, if the control energy amount exceeds a critical control energy amount for the actuators. The control energy amount is required in the actuators for closing the clutch depending on the state variables.

Description

The invention relates to a method for operating a clutch system having at least one clutch, which is closed for transmitting a torque in a drive train by a position energy absorbing actuators, which is controlled differently depending on a state variable, such as the ambient temperature.

From the German patent application DE 10 2005 039 383 A1 a method for clutch control for wet clutches is known in which it is determined whether a viscosity of clutch fluid is above a predetermined threshold. If so, the clutch / transmission control is adjusted so that the clutch fluid transfers additional clutch energy and the clutch fluid is heated by the additional energy. From the German patent application DE 10 2008 053 387 A1 a method for controlling an automated by means of an electromechanical disengagement unit closing friction clutch for a motor vehicle is known, which when starting the motor vehicle in a predetermined, depending on at least one operating condition of the motor vehicle number of cycles and is engaged.

The object of the invention is to enable the operation of a clutch system with at least one clutch, which is used to transmit a torque in a drive train by a position energy absorbing actuators, which is controlled differently depending on a state variable, such as the ambient temperature when the state variable, in particular the ambient temperature, assumes extreme values, in particular extremely low values.

The object is achieved in a method for operating a clutch system with at least one clutch, which is closed for transmitting a torque in a drive train by a position energy absorbing actuators, which is controlled differently depending on a state variable, such as the ambient temperature, that the power consumption of the Aktorik when closing the clutch is reduced when the required by the actuators to close the clutch depending on the state variable job amount exceeds a critical for the actuators job site. As a result, the driver of a motor vehicle equipped with the drive train described above is given the option of being able to close the clutch even at low temperatures, so that the driver can approach the vehicle and change gears. The reduction of the power consumption of the actuators can lead to a reduced coupling dynamics taking into account all safety-critical processes. However, it is ensured by the inventive method that the clutch system is heated by the movement and the heat of an internal combustion engine in the drive train quite low even at low outside temperature far enough that no appreciable dynamics restrictions or comfort restrictions are felt. By means of the method according to the invention, it is possible to prevent the location energy from reaching the limit value critical for the control unit, which would lead to a shutdown of the actuators. Turning off the actuators would in particular make it impossible to start the motor vehicle.

A preferred embodiment of the method is characterized in that the power consumption of the Aktorik when closing the clutch is reduced or turned off when a controller protection model emits a warning that required to close the clutch depending on the state variable Stellenergiemenge critical for the actuators Exceeds the amount of power. The actuator system may comprise, for example, an electromechanical actuator, preferably a lever actuator, which is actuated by an electric motor operated with motor current. The motor current, which is set when the coupling is actuated, depends on the direction of current supply and on the actuator temperature. The highest motor energization results at extremely low ambient temperatures and closing clutch. At extremely low ambient temperatures, for example, below minus 30 degrees Celsius, a set for the clutch actuation maximum current limit can be achieved, which represents the critical amount of power for the actuators. To protect a control unit, a controller-internal protection model can be used, which protects the power amplifiers and thus the electronics from overload, that is from an inadmissibly high electrical energy by first emitting a warning and as a further increased response, the power amplifier switches off. By the method according to the invention such a power disconnection is prevented, so that the coupling system can be operated even at extreme ambient temperatures.

A further preferred exemplary embodiment of the method is characterized in that a desired clutch position is lowered from a clutch target position to a current clutch actual position, in order to reduce or switch off the energy intake of the actuators when the clutch is engaged. As a result, for example, a charge controller can lower the motor current of the actuator of the actuator so that the output stage cools down accordingly and the warning for overload is switched off.

A further preferred embodiment of the method is characterized in that the power consumption of the Aktorik when closing the clutch is reduced or turned off until the warning of the ECU protection model is canceled. As a result, a cooling of an electric motor or an electronic power amplifier is made possible, with or an actuator, for example, a lever actuator, the actuator is actuated to close the clutch.

A further preferred embodiment of the method is characterized in that the setting energy of the actuator when closing the clutch is increased again when the warning of the ECU protective model is canceled. As a result, the coupling can be further closed by means of the actuators as soon as the electric motor or the electronics output stage have cooled sufficiently.

A further preferred exemplary embodiment of the method is characterized in that a desired clutch position is raised again to the clutch target position in order to increase the power consumption of the actuators when the clutch is engaged. A corresponding routine for downsizing and re-increasing the desired clutch position can be programmed in a control unit software.

A further preferred embodiment of the method is characterized in that the power consumption of the Aktorik when closing the clutch is gradually reduced or turned off and increased until the current actual clutch position coincides with one or the target position coupling. By energy input into the clutch and the actuation of the actuator, the clutch system heats up very quickly, which reduces the energy consumption during clutch operation and quickly returns to the normal, comfortable function of the clutch system.

A further preferred embodiment of the method is characterized in that the power consumption of the Aktorik when closing the clutch is reduced by a control unit or switched off and increased. An advantage of the method according to the invention is the assurance of the availability of the coupling system and thus of the vehicle at very low ambient temperatures. In addition, if the method according to the invention is taken into account in the design of the electronic components, larger and more powerful electronic components for the control unit can be dispensed with, which results in installation space and cost advantages.

A further preferred embodiment of the method is characterized in that the power consumption of the Aktorik when closing the clutch by the control unit is reduced or turned off and increased by a motor current is reduced by the control unit or switched off and increased. The reducing or switching off and increasing the motor current can be done via a charge controller.

A further preferred exemplary embodiment of the method is characterized in that the motor current of the actuator for increasing and reducing the power consumption of the actuators via the control unit is adjusted or varied between a quiescent current and a maximum motor current. The entire process should be provided with a corresponding hysteresis, which is stored either in the overload model, or in the subsequent system reaction.

Further advantages, features and details of the invention will become apparent from the following description in which, with reference to the drawings, an embodiment is described in detail.

The single accompanying figure shows in three stacked Cartesian coordinate systems in ascending order the status of a controller, the motor current of a clutch actuator and the position of the clutch actuator or the clutch torque over time.

In 1 is in three superimposed Cartesian coordinate diagrams 1 . 2 . 3 the status 10 a control unit, the motor current 20 for actuating a clutch actuator and the actual position 30 the clutch actuator applied over time. The control unit and the clutch actuator belong to an automated clutch system in the drive train of a motor vehicle. The powertrain includes an internal combustion engine, the clutch system with the clutch and a transmission, for example a parallel shift transmission. The clutch in the automated clutch system is closed by active actuation.

The properties of a mechatronic Kupplungsaktorik, in particular an electromechanical actuators, are temperature-dependent, so that at low temperatures a much larger job energy is required than at high temperatures. This can lead to the fact that at very low temperatures, for example less than 30 degrees Celsius, the requisite power demand exceeds the maximum electrical energy allowed for the control unit. In the case, a protection model in the Control unit shut down the appropriate motor output stage to protect the electronic components. The shutdown of the control unit limits the availability of the clutch system, so that, for example, no approach of the vehicle or no gear change at very low temperatures is possible.

This disadvantage is avoided according to the method according to the invention in that a warning of the control device protection model in the activation of the clutch actuator is taken into account by a new strategy. When the controller protection model issues a warning, the power consumption during control is reduced, allowing the electronic components to cool down. After a cooling down phase, the warning is canceled and the activation is continued with high energy.

In 1 you can see that the motor current 20 after a jump request 11 of the controller increases in steps, resulting in a linear increase of the actual position 30 of the clutch actuator leads. The clutch actuator thus moves with its current actual position 30 linear to a target position 31 to. Through a step 12 an overload warning of the controller is indicated, which causes the motor current 20 from a maximum motor current 21 on a quiescent current 22 is reduced. At the same time becomes a target position 32 from the target position 31 to the current actual position 30 reduced. The motor current 20 remains on the quiescent current 22 reduced until the overload warning 12 will be annulled.

In 1 you can see that the activation of the clutch actuator depends on further overload warnings 13 . 14 done in several stages. Although the clutch is no longer so conveniently closed by the step-by-step activation, the control unit can be switched off by the cooling phases in which the clutch actuator only uses the quiescent current 22 energized, be avoided. The actual position 30 The clutch actuator gradually approaches the target position 31 that at 15 after a final stage with maximum motor current 21 is reached.

A major advantage of in 1 illustrated method is to ensure the availability of the coupling system and thus the vehicle at very low temperatures. In addition, if the method is taken into account in the design of the electronic component, can be dispensed with larger and more powerful electronic components for the control unit, resulting in space and cost advantages.

The entire process should be provided with a corresponding hysteresis, which is stored either in the overload model or in the subsequent system reaction. The method according to the invention can be used not only for electromechanical actuators but also whenever the changed system behavior of an actuator system, especially at low temperatures, requires a high actuation energy.

LIST OF REFERENCE NUMBERS

1

Cartesian coordinate diagram

2

Cartesian coordinate diagram

3

Cartesian coordinate diagram

10

Status of a controller

11

branch request

12

step

13

step

14

step

15

target position

20

motor current

21

maximum motor current

22

quiescent current

30

Actual position

31

target position

32

target position

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102005039383 A1 [0002]
• DE 102008053387 A1 [0002]

Claims (10)

Method for operating a clutch system with at least one clutch, which is closed for transmitting a torque in a drive train in a motor vehicle by a position energy absorbing actuators, which is controlled differently depending on a state variable, such as the ambient temperature, characterized in that the Stellenergieaufnahme the actuator is reduced when closing the clutch when the required by the actuators to close the clutch depending on the state variable job amount exceeds a critical for the actuators job site. A method according to claim 1, characterized in that the power consumption of the Aktorik when closing the clutch is reduced or turned off when a controller protection model warning ( 12 . 13 . 14 ) deduces that the amount of energy required to close the clutch as a function of the state variable exceeds the critical amount of energy for the actuators. Method according to one of the preceding claims, characterized in that a clutch setpoint position ( 32 ) from a coupling target position ( 31 ) to a current actual clutch position ( 30 ) is lowered in order to reduce or switch off the power energy absorption of the actuator when closing the clutch. Method according to one of the preceding claims, characterized in that the power consumption of the Aktorik when closing the clutch is reduced or turned off until the warning ( 12 . 13 . 14 ) of the ECU protection model is canceled. Method according to one of the preceding claims, characterized in that the power consumption of the Aktorik when closing the clutch is increased again when the warning ( 12 . 13 . 14 ) of the ECU protection model is canceled. Method according to one of the preceding claims, characterized in that a clutch setpoint position ( 32 ) back to the coupling target position ( 31 ) is raised to increase the power consumption of the Aktorik when closing the clutch. Method according to one of the preceding claims, characterized in that the power consumption of the Aktorik when closing the clutch is gradually reduced or switched off and increased until the current actual clutch position ( 30 ) with one or the coupling target position ( 31 ) matches. Method according to one of the preceding claims, characterized in that the power energy absorption of the actuators when closing the clutch is reduced by a control unit or switched off and increased. Method according to one of the preceding claims, characterized in that the power consumption of the Aktorik when closing the clutch by the control unit is reduced or switched off and increased by a motor current ( 20 ) is reduced or switched off and increased by the control unit. Method according to one of the preceding claims, characterized in that the motor current of the actuator for increasing and reducing the power energy consumption of the actuators via the control unit between a quiescent current ( 22 ) and a maximum motor current ( 21 ) is adjusted.

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