Patent ID: 7344475

Claim:
A method for controlling a drive train ( 1 ) of a vehicle, especially an all-terrain vehicle having a prime mover ( 2 ), a multi-group transmission ( 4 ), an output means and a control apparatus for the regulation of the drive train ( 1 ), the multi-group transmission ( 4 ) comprising an automatic transmission ( 8 ) and a range group ( 9 ) connected downstream to the automatic transmission ( 8 ) in a direction of power flow, the method comprising the steps of: changing a ratio of the range group ( 9 ) by closing a first shifting elements ( 24 , 25 ) of the range group ( 9 ); synchronizing and opening a second shifting element ( 24 , 25 ) of the range group ( 9 ); and automatically selecting a combination of a ratio of the automatic transmission ( 8 ) that with the changed ratio of the range group ( 9 ) will achieve a predetermined ratio for the multi-group transmission ( 4 ) for all gear stages by means of a superimposed operational strategy; wherein the ratio of the automatic transmission ( 8 ) is selected according to the superimposed operational strategy so that in combination with the ratio of the range group ( 9 ) a change in output rotational speed of the multi-group transmission is minimized for the predetermined ratio of the multi-group transmission, and wherein synchronization of the shifting elements ( 24 , 25 ) of the range group is performed by synchronization of shifting elements (A-E) of the automatic transmission, and fulfilling a demand of a driver (m mot-f ) for alteration of the torque (m mot ) of the motor ( 2 ) during the change of the ratio of the range group ( 9 ) upon the conclusion any ratio change via a control apparatus.