VERFAHREN UND VORRICHTUNG ZUM STEUERN EINER KRAFTUEBERTRAGUNG FUER FAHRZEUGE MIT EINEM STUFENLOSEN GETRIEBE UND EINEM ZUSATZGETRIEBE.

摘要

A method and apparatus for controlling a power transmitting system for an automotive vehicle, including a continuously variable transmission (CVT) and an auxiliary transmission which is connected to the CVT and which is automatically shifted from one of two or more forward drive positions to the other depending upon operating conditions of the vehicle. To control the speed ratio of the CVT, a target speed of the input shaft of the CVT is determined according to one of different relationships between the target speed and at least one variable such as a currently required output of the engine. The relationships are stored in memory, corresponding to the forward drive positions of the auxiliary transmission. The appropriate relationship is selected depending upon the forward drive position in which the auxiliary transmission is currently placed while the transmission shift lever is in an auto-shift or engine-brake position. The automatic shift-down and shift-up operations of the auxiliary transmission may be effected according to predetermined shift patterns corresponding to drivability modes of the vehicle selected on a suitable drivability selector device.