Patent ID: 7762922

Claim:
A method of operating a parallel hybrid drive train ( 1 ) of a vehicle including an internal combustion engine ( 2 ), an electric engine ( 3 ) located between the internal combustion engine ( 2 ) and an output ( 5 ), a first frictionally engaged shifting element ( 8 ) located between the electric engine ( 3 ) and the output ( 5 ) and a second frictionally engaged shifting element ( 7 ) located between the internal combustion engine ( 2 ) and the electric engine ( 3 ), comprising the steps of: adjusting a nominal output torque (m_fahr_soll) on the output ( 5 ) by adjusting the transmitting capacity of the first shifting element ( 8 ) under control according to the required nominal output torque (m_fahr_soll) so that the first shifting element ( 8 ) has a transmitting capacity required for providing the nominal torque (m_fahr_soll) on the output ( 5 ), adjusting an input rotational speed (n_ 3 ) of the electric engine ( 3 ) under regulation during a starting process of the internal combustion engine ( 2 ) to maintain the first shifting element ( 8 ) in a slip operation and to provide the nominal output torque (m_fahr_soll) on the output ( 5 ) during at least the starting process of the internal combustion engine ( 2 ), including during the starting process of the internal combustion engine ( 2 ), adjusting the input rotational speed (n_ 3 ) of the electric engine ( 3 ) according to at least one of the nominal output torque (m_fahr_soll) on the output, a controlled standard (m_ 7 ) of the transmitting capacity of the second shifting element ( 7 ) and a regulation divergence between a nominal standard (d_omg_soll) of a slip of the first shifting element ( 8 ) and an actual slip (omg_ist) of the first shifting element ( 8 ), and adapting control portions of a nominal standard of the input torque (m_ 3 ) of the electric engine ( 3 ) by way of correction control blocks (K 2 , K 3 ) to an actual operating state of the parallel hybrid drive train ( 1 ).