Zf Friedrichshafen Ag

Friedemann Jauch

Franz-Josef Schuler

Markus Henneken

Thomas Mauz

Kai-Uwe Herbster

Michael Kiefer

Armin Gierling

Friedrich Reiter

Peter Spoerl

Detlef Plath

Peter Wendel

Heinrich Zeller

Manfred Escher

Wolf Dieter Gruhle

Eric Bosch

A method of operating a transmission having a plurality of gears which can operate in an automatic shifting mode, during which a gear is selected automatically depending on the current driving situation, and also in a manual shifting mode during which a gear is selected depending on a driver's command. When the driver commands a shift, a change takes place from the automatic shifting mode to the manual shifting mode. A specific threshold value of the transmission output speed or an equivalent rotational speed value is associated with each gear and, when the driver commands a downshift, a target gear is determined as a function of the current transmission output speed or the equivalent rotational speed value. The gear selected as the target gear is the gear whose specific threshold value is higher than or equal to the current transmission output speed or the equivalent rotational speed value.

Transmission control method

Described is a method for controlling a transmission for motor vehicles, especially an automatic transmission or an automatic gearbox, where a gear ratio (') is adjusted according to operating conditions by means of pre-determined shifting programs ('', &#x201c;Eco', &#x201c;Normal&#x201d;, &#x201c;Sport&#x201d;, &#x201c;Mountain II&#x201d;, &#x201c;Warm-up&#x201d;, &#x201c;Tip&#x201d;) and corresponding specific shifting values (HS, RS) and where in relation to a vehicle's actual operating condition at least one special function (&#x201c;Curve Recognition KE&#x201d;, &#x201c;Rapid Drive Pedal Release FO&#x201d;, &#x201c;Spontaneous Delay Vehicle SVF&#x201d;, &#x201c;Drive Speed Control FGR&#x201d;, &#x201c;Drive Dynamic control ESP&#x201d;) is activated, which prevents the change from an actual gear ratio to a target gear ratio requested by a shifting program within a pre-determined operating range of a vehicle. In a first version of the method, the operating range, wherein a gear ratio change of the transmission is prevented, is changed in relation to applied specific values that depend on the operating condition. In a second version of the method it is planned that the shifting characteristics are changed in relation to applied specific values that depend on the operating condition in such a manner that the operating points of the vehicle that are defined on the side of the shift characteristics, for which gear ratio changes must be performed, are adjusted to the actual operating condition of the vehicle.

Method for controlling the transmission of a vehicle

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 is described for operating an automatic transmission in which a command for changing a current ratio of the automatic transmission is generated when achieving preset operating states of the vehicle automatically or by manual input in a manual shifting mode, the activated manual shifting mode being preferred to an automatic shifting mode. The manual shifting mode is quit when a current vehicle speed is less than a threshold value, or when a longitudinal acceleration of the vehicle is within a defined range, a lateral acceleration is less than a threshold value and a driver type evaluation counter is less than a limiting value.

Method for operating an automatic gearbox on a motor vehicle

A shift device for an automatic transmission of a vehicle, particularly of a motor vehicle, is proposed in which the request to change the current ratio of the automatic transmission upon reaching preset operating states of the vehicle can be automatically generated or by manual input in a manual shifting mode. A pulse counter is here provided by way of successive pulses and manual input can be functionally interlinked wherein a shift signal can be generated depending on the linkage.

Shift device for an automatic transmission of a vehicle

A method for controlling an automatic transmission of a motor vehicle in the event of a spontaneous gas/pedal release (FastOff). The automatic transmission is driven by an internal combustion engine which can be influenced by an accelerator pedal and a signal proportional to a pedal position is fed to an electronic transmission control in which shifting characteristic field is stored and the spontaneous gas/pedal release (FastOff) is detected and an upshift block (FFO=1) is activated when a pedal position gradient (PSTG) falls below a pedal gradient threshold (KF_PSTG). The mode of the upshift block (FFO=1) is removed when a traction operation is detected when an actual engine torque (MMM) exceeds a push-pull line (KL_ZS) stored as a function of a value equivalent to an engine rotational speed (NMO) in dependence on a vehicle acceleration/deceleration (AIST) dependent on an overall tractional resistance (GFW) and pedal gradient thresholds (KW_PSTGPOS, KW_PSTGNEG).

Method for controlling an automatic gearbox of a motor vehicle in the event that the gas/pedal is spontaneously released

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).

Growing community of inventors

Meckenbeuren, Germany

Friedemann Jauch