Zf Friedrichshafen Ag

Kai-Uwe Herbster

Franz-Josef Schuler

Markus Henneken

Friedemann Jauch

Thomas Mauz

Martin-Joachim Bader

Peter Spörl

Oliver Iden

A method for adjusting a ratio of a continuously variable automatic transmission where a nominal ratio is determined according to an accelerator pedal signal value. The nominal ratio is determined according to a modified accelerator pedal signal. When the periodic curve of the accelerator pedal signal has a relative extreme value to the modified accelerator pedal signal, a starting value is assigned which is equal to this extreme value. Until the value of the modified accelerator pedal signal is again equal to the value of the unmodified accelerator pedal signal, the value of the modified accelerator pedal signal is determined by a transfer function.

Ratio control method for a continuously variable transmission

Within the framework of the procedure for optimizing the rocking free of vehicles with an automatic transmission, a multiple clutch gear or an automatic shift gear, in order to recognize a situation which requires a rocking free of the vehicle, the speeds of the driving wheels are compared to the speeds of the non-driven wheels. When the driving wheels are spinning or have a specific speed, without a corresponding increase in speed or speed of the non-driven wheels, the necessity for rocking free of a vehicle is recognized.

Transmission control method for repeated forward-reverse operation

In the method for kick-down switching speed optimization in a motor vehicle with an automatic transmission, the kick-down upshift point is determined as a function of the load conditions and the road inclination in each case.

Kick-down switching speed optimization for an automatic transmission of a motor vehicle

A method for modifying a defined adaptive driving strategy, which is stored in the control system for an automatic transmission of a motor vehicle, for adaptation to another type of driver with a different driving style, consists in that the parameters used for the driving strategy are modified by the other driver, the data for this being input to the transmission electronics via an input unit and an interface with the electronics.

Method for modifying a defined adaptive driving strategy

A method for control of an automatic transmission for a motor vehicle equipped with cruise control consists in that during cruise control of the transmission control changes to a separate driving program which is function of external influences, especially of the road inclination. This driving program is updated according to external influences. In the &ldquo;set&rdquo; state, change is made to the separate driving program and in the &ldquo;restore&rdquo; state the control can be adjusted so that the separate driving program be activated immediately or not until reaching the &ldquo;set&rdquo; control state.

Method for controlling an automatic transmission for a motor vehicle

The invention relates to a method for control of an automatic transmission of a motor vehicle wherein an electronic transmission control, by means of signals proportional to wheel speeds (NRA , NRA ), determines a transverse acceleration value (AQ) for outputting to additional program modules. The determined wheel speeds (NRA , NRA ) which enter in the transversal acceleration value (AQ) are corrected by vehicle wheels in a tolerance balance module of the wheels (M ) when a dynamic tire radius (RDYN) in one of the vehicle wheels diverges from a tire radius given in an optimum tire geometry.

Method for controlling an automatic gearbox involving determination of a transverse acceleration value

A method for controlling an electronically controlled automatic transmission wherein the spontaneous gas/pedal release (FastOff) is detected and an upshift prevention system is activated when a pedal position gradient (PSTG) is lower than a pedal position gradient threshold (KF_PSTG); the state of the upshift prevention system (FFO&equals;1) is active until a) a traction operation is detected when the actual pedal position value (PST) exceeds a traction-thrust characteristic line (KF_ZS) and of an acceleration potential value (FBN) equivalent to a road gradient value; and/or b) a time (T , T ) has elapsed after a defined time period (THSV , THSV ) wherein the state of the upshift prevention system (FFO&equals;1) is abandoned.

Method for controlling the automatic gearbox of a motor vehicle during spontaneous release of the accelerator pedal

The invention relates to an urban driving operating method for an electronically controlled automatic transmission in which a driving speed characteristic (vf) is determined and it is possible to recognize an urban driving state when the driving speed characteristic (vf) is within a presettable value range with an upper limit and in which in addition a driving activity characteristic (FCOUNTER) is continuously determined. It is proposed according to the invention that the urban driving state be recognized when the driving activity characteristic (FCOUNTER) is also within a presettable value range with an upper limit and that a drive program optimized for the urban driving state be accessed.

Urban driving operating method for an electronically controlled automatic gearbox

In a method for controlling an automatic transmission of a motor vehicle having an electronic gear control (EGS) that continuously exchanges signals with a vehicle dynamics regulator (FDR), the electronic gear control (EGS) receives signals (SL) of an anti-slip control system (ASC) and/or of an anti-blocking system (ABS). In addition the vehicle dynamics regulator (FDR) is functionally linked with a dynamic stabilizer (DS) which in predefined operating situations issues a signal (SV) to the electronic gear control (EGS) via the vehicle dynamics control (FDR), which signal is processed simultaneously with the incoming signals (SL) from the anti-slip control system (ASC) and/or the anti-blocking system (ABS).

Method for controlling the automatic gearbox of a motor vehicle

The invention relates to a method for controlling an automatic transmission wherein several shift programs are provided and allocated to specific values of a driving activity characteristic (FAKG) and in each shift program shifting characteristic lines and shifting rotational speeds are determined by accelerator pedal positions. The shifting rotational speeds are immediately increased to higher rotational speeds when the driver quickly depresses the accelerator pedal causing the accelerator pedal position gradient to exceed a presettable limit value. According to the invention, it is proposed that the shifting rotational speeds be determined according to the actual value of the driving activity characteristic by interpolation between shifting characteristic lines from two respective adjacent shift programs and the driving activity characteristic be immediately increased by a presettable offset amount when the accelerator pedal position gradient exceeds the presettable limit value.

Method for controlling an automatic gearbox

The invention relates to a method for controlling a high-temperature operating mode of an automatic transmission wherein at least one value of an actual engine (CMO) or transmission (CGT) temperature is continuously measured. In the electronic control unit several gear shift control programs are stored and are accessed at normal operating temperatures according to an evaluation counter provided with a driving activity characteristic. It is proposed that the evaluation counter be provided with a high-temperature operating value (MAX(UDCHMMO, UDCHMGT)) with which is associated a gear shift program which also has temperature-lowering properties when the actual temperature value (CMO, CGT) is higher than a first limit value (MOMIN, GTMIN).

Method for controlling a high temperature operating mode of an electronically controlled automatic gearbox

For an automatic transmission ( ) a downshift function is proposed in which, with the actuation of a brake pedal, a new downshift point (RA(NEU)) is calculated when the throttle valve is closed by adding to a basic downshift point (RS(ORD)) a characteristic variable (K ) wherein the characteristic variable (K ) is determined from a driving activity (FA) and a calculated brake pressure via a characteristic field.

Automatic gearbox with a downshift function

When a cold start condition exists, an electronic gear control (,) calculates for an automatic transmission (,) driven by an internal combustion engine (,) the energy throughput of the internal combustion engine (,). The energy throughput is added up and compared with a limit value. The shift points of the automatic transmission (,) are pushed up to higher values as long as the calculated value remains less than the limit value.

In a process for control of an automatic transmission (3) in a vehicle, it is proposed to set an electronic transmission control (4) for a driving state low friction value when slip is detected on the input gears of the vehicle or an ACS deceleration is detected. In an ACS deceleration a meter is determined, via an ACS evaluation function, from the actual acceleration of the vehicle or a parameter (e.g., gear speed increase) corresponding to the actual acceleration. When slip occurs, a meter is determined, via a slip evaluation function, from the theoretical/actual comparison of the vehicle acceleration or a parameter (e.g., torque reserve) corresponding to said comparison. In both an ACS deceleration or when a slip occurs, a winter operation mode is then activated when the meter count exceeds a limit value.

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Friedrichshafen, Germany

Kai-Uwe Herbster