Modulating an engine torque for synchronizing a motor speed with an electrical machine rotation speed for the clutch-coupling-in a hybrid vehicle

It is a system and method for controlling a hybrid vehicle having an engine, an electric machine and a transmission provided which are selectively coupled by a clutch in series and having the modulating of the motor torque while the clutch is disengaged, and as long as the engine speed is less than is the electrical machine rotation speed for increasing the engine speed. The clutch is engaged to connect the engine with the electric motor in response to the engine speed, which exceeds the electrical machine rotation speed.