Method for determining the exhaust gas temperature of an internal combustion engine

A method for thermally protecting a turbocharger of an internal combustion engine, the method comprising:

• measuring, using a lambda sensor, a lambda value of the exhaust gas of the internal combustion engine during an essentially steady-state operation of the internal combustion engine;
• determining, by an engine controller, an exhaust gas temperature as a function of the measured lambda value using a functional relationship between the exhaust gas temperature and the lambda value;
• using the engine controller, comparing the determined exhaust gas temperature with an exhaust gas temperature measured during the essentially steady-state operation of the internal combustion engine, and adapting, as a function of the comparison, the functional relationship between the exhaust gas temperature and the lambda value, wherein the adapting includes adjusting a parameter of the functional relationship;
• using the engine controller, checking whether the calculated exhaust gas temperature has exceeded a determined threshold value;
• and
• using the engine controller, varying one combustion parameter of the internal combustion engine, if the check indicates an overshooting, so that the exhaust gas temperature drops below the threshold value.

A control unit for determining an exhaust gas temperature of an internal combustion engine, comprising:

• a lambda sensor to measure a lambda value of the exhaust gas of the internal combustion engine during an essentially steady-state operation of the internal combustion engine;
• a determining arrangement to determine an exhaust gas temperature as a function of the measured lambda value using a functional relationship between the exhaust gas temperature and the lambda value;
• a comparing arrangement to compare the determined exhaust gas temperature with an exhaust gas temperature measured during the essentially steady-state operation of the internal combustion engine;
• and
• an adapting arrangement to adapt, as a function of the comparison, the functional relationship between the exhaust gas temperature and the lambda value, wherein the adapting includes adjusting a parameter of the functional relationship.

A non-transitory computer readable medium having a computer program including program codes which, when executed on a processor, execute a method for determining an exhaust gas temperature of an internal combustion engine, the method comprising:

• determining, using a lambda sensor, a lambda value of the exhaust gas of the internal combustion engine during an essentially steady-state operation of the internal combustion engine;
• determining an exhaust gas temperature as a function of the measured lambda value using a functional relationship between the exhaust gas temperature and the lambda value;
• and
• comparing the determined exhaust gas temperature with an exhaust gas temperature measured during the essentially steady-state operation of the internal combustion engine, and adapting, as a function of the comparison, the functional relationship between the exhaust gas temperature and the lambda value, wherein the adapting includes adjusting a parameter of the functional relationship.