KR101845100B1

KR101845100B1 - Method for controlling an automatic friction clutch

Info

Publication number: KR101845100B1
Application number: KR1020127034191A
Authority: KR
Inventors: 울리히 노이베르트; 미햐엘 로이셸
Original assignee: 섀플러 테크놀로지스 아게 운트 코. 카게
Priority date: 2010-06-29
Filing date: 2011-06-09
Publication date: 2018-05-18
Also published as: DE102011103773A1; DE112011102179A5; WO2012000471A1; KR20130089582A

Abstract

The present invention relates to an open circuit control method of an automatic friction clutch disposed in an automotive powertrain between an internal combustion engine and a transmission, wherein the engine torque delivered from the internal combustion engine is closed-loop controlled in accordance with the clutch slip occurring in the friction clutch. The present invention is characterized in that the engine torque is limited by the interventional torque (M _intervening ) which depends on the desired engine speed (? _{Engine, setting} ) change.

Description

TECHNICAL FIELD [0001] The present invention relates to an automatic friction clutch,

The present invention relates to an open circuit control method of an automatic friction clutch disposed in an automotive powertrain between an internal combustion engine and a transmission, wherein the engine torque delivered from the internal combustion engine is closed-loop controlled in accordance with the clutch slip occurring in the friction clutch.

German Published Patent Application DE 10 2009 014 467 A1 discloses a method for controlling the open-loop control of an automatic friction clutch in a power train between an internal combustion engine and a transmission. In this method, the engine torque of the internal combustion engine is controlled by the slip Closed loop control.

The object of the present invention is to further improve the comfort and / or availability of an automatic friction clutch disposed in an automotive powertrain between an internal combustion engine and a transmission, wherein the engine torque delivered from the internal combustion engine is a clutch slip As shown in FIG.

The above object is achieved by an open-circuit control method of an automatic friction clutch disposed in an automotive powertrain between an internal combustion engine and a transmission, wherein the engine torque transmitted from the internal combustion engine at this time is a closed- In which the engine torque is limited by the interventional torque (M _intervening ) depending on the desired engine speed ( _{engine, setting} ) change. The engine speed ([omega] _{engine, setting} ) will be raised or lowered, for example, while maintaining the limit of frictional force applied to the friction clutch. The change in engine speed ( _{engine, setting} ) with time is considered in this intervention torque (M _intervening ).

One preferred embodiment of the above method is characterized in that the engine torque is limited by the interventional torque (M _intervening ) depending on the inertial torque (J _engine ) on the engine side of the friction clutch. The inertial torque (J _engine ) is the mass inertia torque of the mass formed on the engine side of the friction clutch.

A further preferred embodiment of the method is characterized in that the interventional torque (M _intervention ) is limited according to the offset torque (M _offset ) determined according to the following equation.

In this case, "J _engine " corresponds to the inertial torque of the engine side of the clutch,

Corresponds to the desired engine speed slope.

A further preferred embodiment of the method is characterized in that the interventional torque (M _intervention ) is limited according to the maximum permissible frictional force (P _limit ). This allowed maximum frictional force (P _limit ) depends on the clutch torque and / or the slip that occurs.

A further preferred embodiment of the method is characterized in that the interventional torque (M _intervention ) is determined according to the following equation:

In this case, "M _intervention " corresponds to the limited engine intervention torque, and "P _limit " corresponds to the maximum permitted friction force. "omega _slip " corresponds to the number of slip rotations in the clutch shown in radians / seconds. The "J _engine " corresponds to the inertial torque of the engine side of the clutch,

Corresponds to the desired engine speed slope.

A further preferred embodiment of the method is characterized in that the maximum friction force (P _limit ) is multiplied by a correction factor (k) which takes into account the engine torque and / or the inaccuracy in the clutch torque. Through this correction coefficient k, the maximum permissible frictional force (P _limit ) changes.

A further preferred embodiment of the method is characterized in that the correction coefficient k is determined according to the following equation:

It can be calculated through integration of the engine torque or clutch torque plus the dynamic mass inertia component, for example, that there is a larger deviation during the starting operation that allows for correction of the maximum permitted frictional force (P _limit ). By the correction coefficient k, the maximum permissible frictional force (P _limit ) can be minimized.

A further preferred embodiment of the method is characterized in that the engine torque is limited by the interventional torque (M _intervention ) at the time of starting, especially at the starting of the hill. In this case, the frictional force is indirectly reduced through a suitable reduction of the engine torque, more specifically, as high as possible driving comfort and vehicle availability are obtained while being reduced.

Additional advantages, features, and details of the present invention are described in detail in the following description of the embodiments.

The method according to the present invention is a strategy for protecting an automatic friction clutch disposed in an automotive powertrain between an internal combustion engine and a transmission. In this case, the frictional force applied to the friction clutch must be reduced to protect the clutch from overload. In this case, the precondition is the maximum specified friction force, the known slip revolution number (the difference between the engine input revolution and the transmission input revolution number) in the clutch to be protected, and the possibility of engine intervention in the drive engine limiting the torque.

The applied frictional force corresponds to the following equation.

In this case, "P" corresponds to friction force (Watt), "M" corresponds to clutch torque (Newton meter), and "ω _slip " corresponds to slip revolution speed (radian / sec) in clutch.

In order to limit the applied frictional force, the clutch torque should be limited according to the clutch slip according to the above equation. Since the clutch slip must generally be reduced at the same time and the engine speed must be adjusted to a certain value, the engine torque must generally be limited through corresponding intervention. Therefore, a corresponding clutch torque is also obtained for a constant engine speed. If the engine speed has to rise or fall under a tight hold of the output limit, a further offset to the intervention torque following the equation is obtained.

Corresponds to the desired engine speed slope.

Thus, limited engine intervention is obtained in the following equation.

In this case, "M _intervention " corresponds to limited engine intervention,

The "P _limit " corresponds to the maximum frictional force allowed.

Thus, through the usual closed-loop control of the clutch control device, the desired limited clutch torque is also indirectly obtained, without having to directly intervene in the clutch torque closed-loop control, which is usually matched for comfort behavior. That is, therefore, the actual frictional force also depends on the closed-loop control to preset the clutch torque.

If variation of the maximum frictional force within a short time is to be prevented, the clutch torque must also be directly limited. However, a direct limitation of the clutch torque usually results in a loss of comfort, and this loss of comfort should be prevented through cumbersome filtering. Pure engine intervention has advantages in the complexity of closed loop control, since most of the above types of filtering through clutch torque closed loop control using engine torque as a reference variable have already been implemented.

Low complexity may be required since the method according to the present invention is a protection strategy that does not affect normal cases. The great advantage of engine torque limitation is that in engine torque at the phase with (large) clutch slip, the engine torque does not directly affect the acceleration of the vehicle because the engine torque in the power train is formed substantially only through the clutch torque. In this case, the engine torque only affects the engine speed curve.

It may be necessary to vary the output limit value due to engine torque and / or inaccuracies in the clutch torque. For example, through integration of the engine torque or the clutch torque plus the dynamic mass inertia component, it can be calculated whether there is a larger deviation during starting.

Thus, for example, the correction factor k can be determined, and the output limit (P _limit ) is corrected when the deviation is greater through such correction factor.

When the clutch torque is recognized to be larger than the effective engine torque, the allowed frictional force can be minimized through such correction factor.

In this way, it can be ensured that the allowed frictional force is not exceeded.

The method according to the invention is preferably applied to a dual clutch project. This method may be part of the clutch strategy in the clutch open circuit control software for the automatic clutch, for example. In this case, this method is usually required to protect against misuse in the starting situation, for example when the driver is driving the accelerator pedal while the vehicle is rolling backwards with the forward gear engaged. However, this method is generally applicable in all driving situations where slip occurs.

There is a possibility that the existing clutch open-loop control device implements the requirement according to the maximum allowable frictional force in the (starting) clutch in the automatic clutch open-circuit control device of low complexity and high utilization. In this case, the key concept is to indirectly reduce the friction force through an appropriate reduction of the engine torque, while at the same time achieving high driving comfort and high vehicle availability.

Claims

An open circuit control method of an automatic friction clutch disposed in an automotive powertrain between an internal combustion engine and a transmission, wherein the engine torque transmitted from the internal combustion engine is closed-loop in accordance with a clutch slip generated in the friction clutch, In the control method,
The engine torque is limited by the interventional torque (M _intervening ) depending on the desired engine speed ( _{engine, setting} ) change,
The interventional torque (M _intervening )
Equation

Of the automatic friction clutch (1).

delete

2. The method according to claim 1, characterized in that the maximum friction force (P _limit ) is multiplied by a correction coefficient (k) which takes into account the engine torque and / or inaccuracies in the clutch torque.

7. The method according to claim 6, wherein the correction coefficient (k)

Of the automatic friction clutch (1).

2. The method as claimed in claim 1, wherein the engine torque is limited by an intervention torque (M _intervention ) at the time of starting.