Zf Friedrichshafen Ag

Zf Batavia L.l.c.

Patrick Speicher

Ralf Vorndran

Wolfgang Danz

Udo Gillich

Armin Gierling

Andreas Piepenbrink

Anton Welte

The invention relates to a method for manually stipulating the transmission ratio of a continuously variable transmission (CVT) for a motor vehicle. The CVT comprises a control device, a shifting or selecting device, a starting element and a variator for adjusting the transmission ratio which is driven, in particular, by an internal combustion engine. The control device processes input signals derived from a driver-vehicle system within the framework of an operational strategy for stipulating the transmission ratio, the rotational speed of the drive motor or a variator input rotational speed. In a first automatic operation mode, the operational strategy automatically selects the transmission multiplication. In a second manual operational mode, the driver can directly intervene, via the shifting or selecting device, in the selection of the transmission multiplication. The invention provides, in the second mode of operation, that preset, continuous and vehicle speed-dependent engine rotational speed progressions or variator input rotational speed progressions or transmission ratio progressions can be manually selected. The progressions are displayed as curve traces within upper and lower limits of the adjustment range such that vehicle stand still and a highest possible speed of the vehicle can be attained in each progression.

Method for manually stipulating the transmission ratio of a continuously variable transmission (CVT)

The invention concerns a process for evaluating a driving dynamic request of a driver for the driving strategy of one of an automatic or automated transmission of a motor vehicle. It is proposed to calculate an accelerator pedal stroke, from the accelerator pedal actuation, which is supplied to the driving strategy as an input parameter to the driving strategy equivalent to the driving dynamic request. To this end, a rough value of the accelerator pedal stroke is calculated, especially by subtraction of the accelerator pedal position at beginning of the accelerator pedal movement from the accelerator pedal position, from accelerator pedal values which are in fixed event-dependent ratio to each other. The accelerator pedal stroke results from an event-dependent filtering of the rough value of the accelerator pedal stroke during which a filtering function starts at the end of the accelerator pedal movement, especially when the accelerator pedal position is constant over a presettable time. The rough value of the accelerator pedal, existing at this moment, breaks down by a presettable time function.

Process for evaluating the driving dynamic request of the driver for the driving strategy of an automatic/automated transmission

Within the scope of the process for control of vehicle acceleration for a motor vehicle having a continuously variable transmission, the vehicle acceleration is controlled by the ratio adjustment in the continuously variable automatic transmission with a pattern-based control addition using a status assessment method for assessing the output torque.

Acceleration control for a vehicle with CVT

The invention relates to a method for manual control of the ratio of a continuously variable transmission (CVT) for a vehicle. The CVT has one control device, one shifting or selector device, one starting element and one variator for ratio adjustment and is driven by an internal combustion engine. The control device processes input signals derived from a driver-vehicle system within the scope of an operating strategy under the control of the reduction ratio, the rotational speed of the prime mover, or an input rotational speed of the variator. The operation strategy automatically selects in an automatic operating mode the transmission ratio. In a manual operating mode, the driver can engage directly in the selection of the transmission ratio via the shift or selector device. It is proposed that in the operating mode there is manually preset a signal proportional to the vehicle speed which is further processed as a theoretical guidance for the operating point of the engine-transmission unit. The speed-regulating device controlled on the transmission side can be combined within the manual operating mode with the direct engagement in the selection of the transmission ratio.

Method of ratio control for a CVT in a manual mode

In the process according to the invention for predetermining the ratio of a continuously variable transmission (,), a dynamic driving range is generated. The actual, minimum and maximum acceleration (a_akt, a_min, a_max) is calculated. Further detected is the driver's wish to accelerate or to decelerate (a_fwu) and an acceleration (a_vorg) is determined. Also calculated is a change of ratio per time unit of the continuously variable transmission (iV_pkt), which is guided by the engine speed of rotation during adjustment of the continuously variable transmission (,).

Process for determining the operating point of a continuously variable transmission

The invention relates to a method of adjusting the transmission ratio of a continuously variable gear. The position of a current operating point (B_akt) in a predetermined driving range is constantly adjusted in accordance with the driving situation. The position of the operating point is also determined by range boundaries (UG, OG) which can be varied in accordance with the driving resistance and the driver's manner of driving. The method is characterized in that it simplifies development and application.

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Oberteuringen, Germany

Patrick Speicher