Patent ID: 7260933

Claim:
A method for limiting a boost pressure (p 2 ) of an internal combustion engine ( 1 ) which is supercharged by means of an exhaust gas turbocharger ( 2 ) including a compressor ( 2 . 2 ), said method comprising the steps of: comparing a desired boost pressure value (p 2 _soll, p 2 _solllim 1 ) with a predefined limiting value (p 2 _maxATL) and, when the desired value (p 2 _soll, p 2 _solllim 1 ) exceeds the limiting value (p 2 _maxATL), limiting the desired value (p 2 _soll) to the predefined limiting value (p 2 _maxATL), determining the limiting value (p 2 _maxATL) as a function of an existing operating state (n) of the internal combustion engine ( 1 ) and also a temperature (T 1 ) and a pressure (p 1 ) which occur upstream of the compressor ( 2 . 2 ) of the exhaust gas turbocharger ( 2 ) in the through-flow direction, additionally using a air mass flow rate (dm 1 /dt) which occurs upstream of the compressor ( 2 . 2 ) in the throughflow direction for determining the limiting value (p 2 _maxATL) by means of a simulation model ( 11 , 12 ), said simulation model ( 12 ) being provided as a group of characteristic curves which is subject to parameters, with the ratio of the limiting value (p 2 _maxATL) to the pressure (p 1 ) occurring upstream of the compressor ( 2 . 2 ) in the direction of flow being an output variable, and the temperature (T 1 ) occurring upstream of the compressor ( 2 . 2 ) in the direction of flow serving as a parameter.