Transmission control device

This application claims priority from German patent application serial no. 10 2008 040 663.5 filed Jul. 24, 2008

The invention concerns a transmission control device.

From practice it is already known that in a control device of a transmission, parameters are stored, with whose help gearshifts can be controlled or regulated. With the help of these parameters gearshifts can be harmonized, for example, with various types of motorization or various driving styles. Thus, from practice it is already known to store in a transmission control device sets of parameters which enable comfortable gearshifts, and sets of parameters which enable sporty gearshifts to be carried out.

Starting from that point the present invention addresses the problem of providing a new type of transmission control device.

According to the invention, at least some parameters are stored at least in duplicate, namely firstly for operating the transmission while driving under purely electric motor power using the electric motor exclusively, and secondly for operating the transmission during hybrid driving, using both the internal combustion engine and the electric motor.

With the present invention it is proposed for the first time to store in a transmission control device of a transmission, at least in duplicate, at least some parameters both for operating the transmission while driving purely under electric motor power and for operating the transmission during hybrid driving.

The invention is based on the knowledge that at least some parameters stored in the transmission control device for the control or regulation of gearshifts are influenced by the mass moment of inertia of the drivetrain, and that the mass moment of inertia of the drivetrain changes according to whether the drivetrain is operating under purely electric motor power or in the hybrid mode. With the present invention, gearshifts can be optimally controlled or regulated during both electric-motor and hybrid driving, by virtue of the correspondingly stored parameters.

Preferred further developments of the invention emerge from the subordinate claims and the description presented below. Example embodiments of the invention, to which it is not limited, are explained in greater detail with reference to the drawing, which shows:

FIG. 1 : Block diagram of a drivetrain with a transmission control device according to the invention

FIG. 1 is a very schematic representation of a drivetrain comprising a hybrid drive system with an internal combustion engine 1 , an electric motor 2 and a transmission 3 . The transmission 3 can be an automatic transmission, an automated transmission or even a manual-shift transmission. The transmission 3 converts the traction force supplied by the hybrid drive and delivers it to a drive output 4 . Between the internal combustion engine 1 and the electric motor 2 is connected a clutch 5 . Another clutch 6 is connected between the electric motor 2 and the transmission 3 , the clutch 6 being a starting element. The starting element can also be an integral component of the transmission 3 .

In another design of the drivetrain (not illustrated) a hydrodynamic converter can also be used as the starting element.

The drivetrain configuration represented in FIG. 1 is a hybrid drivetrain. When this is operated purely under electric motor power, the clutch 5 is disengaged and the internal combustion engine 1 is then decoupled from the drive output 4 . When the drivetrain of FIG. 1 is operated in hybrid mode, the clutch 5 is engaged and the internal combustion engine 1 is then coupled to the drive output 4 . From this, it already follows that depending on whether the clutch 5 is engaged or disengaged, the mass moment of inertia of the drivetrain will be different. When driving in the hybrid mode, gearshifts to be carried out are influenced by the mass moment of inertia of the internal combustion engine 1 , the clutch 5 and the electric motor 2 . On the other hand, during purely electric-motor-powered driving the mass moment of inertia of the internal combustion engine 1 is not involved.

As can be seen in FIG. 1 , an electric or electronic transmission control unit 7 is associated with the transmission 3 and an electric or electronic engine control unit 8 is associated with the hybrid drive comprising the internal combustion engine 1 and the electric motor 2 .

The transmission control device 7 exchanges data with the transmission 3 in order to control or regulate gearshifts. The engine control unit 8 exchanges data with the internal combustion engine 1 and the electric motor 2 in order to control or regulate them. Furthermore, the transmission control device 7 and the engine control unit 8 exchange data with one another in order to co-ordinate the control and regulation of the transmission 3 with the control and regulation of the hybrid drive.

In the transmission control device 7 of the transmission 3 are stored parameters on the basis of which gearshifts of the transmission 3 are controlled or regulated.

In the sense of the present invention at least some parameters have to be stored at least in duplicate in the transmission control device 7 , namely firstly for operation of the transmission 3 during exclusively electric-motor-powered driving using the electric motor 2 only, and secondly for operation of the transmission 3 during hybrid driving using both the internal combustion engine 1 and the electric motor 2 .

At least those parameters must be stored at least in duplicate in the transmission control device 7 , which are influenced by the mass moment of inertia of the drivetrain. This enables optimally harmonized gearshifts to be carried out both during purely electric-motor-powered driving and during hybrid driving.

In the transmission control device are stored, preferably both for purely electric-motor-powered driving and for hybrid driving, a plurality of parameter sets each comprising a number of parameters. Thus for example, both for purely electric-motor-powered and for hybrid driving, at least one parameter set can be stored respectively for enabling comfortable gearshifts and at least one parameter set for enabling sporty gearshifts. These parameter sets for purely electric-motor-powered driving and for hybrid driving, designed to enable gearshifts of the same type, i.e. similarly comfortable gearshifts or similarly sporty gearshifts, differ in respect of at least those parameters which are influenced by the mass moment of inertia of the drivetrain. This then makes it possible, both when driving under purely electric power and during hybrid driving, to carry out respectively optimally adjusted comfortable gearshifts and sporty gearshifts.

1 Internal combustion engine

2 Electric motor

3 Transmission

4 Drive output

5 Clutch

6 Clutch

7 Transmission control device

8 Engine control unit