Patent ID: 7645209

Claim:
A method of operating a parallel hybrid powertrain ( 1 ) of a motor vehicle ( 19 ) in which the parallel hybrid powertrain ( 1 ) comprises a single output ( 5 ), plurality of multiple drive units ( 2 , 3 ) comprising at least one internal combustion engine ( 2 ) and at least one electric motor ( 3 ), the at least one electric motor ( 3 ) being located in the parallel hybrid powertrain ( 1 ), between the single output ( 5 ) and the at least one internal combustion engine ( 2 ), a first friction-locking shifting element ( 7 ) being located between the internal combustion engine ( 2 ) and the electric motor ( 3 ), and a coupling element ( 8 A), having a rotational speed dependent known value, and at least a second friction-locking shifting element ( 30 ) being located between the electric motor ( 3 ) and the single output ( 5 ), a target-output torque (m_fahr_soll), which propels the output ( 5 ), depends on a power transmission capacity of the second shifting element ( 30 ), the method comprising the steps of: allowing the power transmission capacity of the second shifting element ( 30 ) to depend on the required target output torque (m_fahr_soll); controlling the power transmission capacity of the second shifting element ( 30 ) such that the second shifting element ( 30 ) has the power transmission capacity required to achieve the target output torque (m_fahr_soll) at the output ( 5 ); controlling a target drive torque (m_ 2 _soll, m_ 3 _soll), produced by the plurality of drive units ( 2 , 3 ), by a target slippage parameter (s_ 30 _soll) of the second shifting element ( 30 ), which depends on the target output torque (m_fahr_soll); and controllably regulating the target slippage parameter (s_ 30 _soll) of the second shifting element ( 30 ) depending on a further operating state parameter (s_ 30 ) of the parallel hybrid powertrain ( 1 ).