20090171538 | System and method for controlling driving force of hybrid electric vehicle - The present invention provides a system and method for controlling a driving force of a hybrid electric vehicle which can reduce clutch engagement shock generated during transition from an electric operation mode to an internal combustion engine running mode. For this purpose, the present invention provides a driving force control system of a hybrid electric vehicle including an engine, a motor-generator and a clutch, in which at least one starter-generator directly connected to the engine. The output torques of the engine and the starter-generator are controlled so as to make a difference between the rotational speed of the engine and the rotational speed of the motor-generator reach a predetermined threshold value, and the clutch is engaged when the difference between the rotational speeds reach the value. | 07-02-2009 |