METHOD FOR CONTROLLING A DRIVETRAIN OF A VEHICLE

摘要

A method is disclosed, for controlling a drivetrain of a vehicle, in particular an off-road vehicle, with a drive unit, a multi-group transmission, an output and a control device. The multi-group transmission comprises at least an automatic gearbox and a range-transfer box arranged thereafter. On changing the ratio in the range-transfer box, a) the drivetrain is unloaded by changing the torque of the drive unit, b) a switching element to be disengaged in the range-transfer box is disengaged, c) a switching element to be engaged in the range-transfer box is synchronised and engaged and d) a ratio of the automatic gearbox is changed such that a change in the ratio of the multi-group transmission is less than a change in the ratio of the ratio-transfer box alone. A combination of a ratio in the automatic gearbox and a ratio in the range-transfer box is selected by a command operational strategy, to give the desired ratio for the multi-group transmission, whereby the input speed to the range-transfer box for the desired ratio of the multi-group transmission is kept to a minimum.