Zf Friedrichshafen Ag

Schneider Electric Industries Sas

Siegfried Dobler

Karl K Mayer

Uwe Heitz

Arun-Kuma Chatterjee

Udo Wolz

A power train control (,) for a vehicle (,) or an automotive machine with a prime mover (,) with a governor (,) and a continuously variable transmission (,) with a ratio control (,). The power train control (,) coordinates the ratio control and the governor issuing a theoretical speed n_mot_nom to the governor (,) for the prime mover (,) and a nominal transmission ratio i_nom to the ratio control (,). The power train control (,) is designed as a combination of two governors, the transmission output speed governor (,) and the governor (,) for relief of the prime mover (,). The transmission output speed governor (,) receives the transmission output speed n_out as a control variable and generates the nominal speed n_mot_nom for the prime mover (,) as a manipulated value, and the governor (,) for relief of the prime mover (,) by the speed n_mot of the prime mover (,) as a control value and a transmission ratio correction value &Dgr;i as a manipulated value. The nominal transmission ratio i_nom is specified by addition of this correction value &Dgr;i to a coarse transmission nominal ratio i_0_nom, with the latter being specified as function of the nominal speed n_mot_nom of the prime mover (,) and the nominal transmission output speed n_out_nom set by the driver (,).

Power train control system

The invention concerns a system for evaluating vehicle, drive and operation parameters of a vehicle to select and adjust by means of a microprocessor a speed ratio of a gear according to predetermined calculation rules, characteristic values and characteristic fields wherein an acceleration of the vehicle is mathematically calculated from a number of revolutions of a drive train comprising engine and gear, the number of revolutions corresponding to the driving speed. The problem is to provide for different gear types a uniform system which requires only a few parameters adapted to the vehicle for selecting speed ratio and gear shift. This is attained by the fact that a minimum dwelling time (&Dgr;t,) is associated to each speed ratio range. To each change of speed ratio (i,) is further associated an adjustment time (&Dgr;t,) which in the average is required for the gear to complete a speed ratio change (&Dgr;i,). From the minimum dwelling time (&Dgr;t,) and the adjustment time (&Dgr;t,) is calculated, taking into account the vehicle acceleration (a), a change in number of revolutions (&Dgr;n,, &Dgr;n,) of the engine during said times. The speed ratio change (&Dgr;i,) to be carried out is calculated from a set number of revolutions (n,) or a gear shift number of revolutions (n,), and is carried out when the real number of revolutions (n,) reaches or exceeds the gear shift number of revolutions (n,)

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Langenargen, Germany

Siegfried Dobler