Method and device for forming a simulated signal of the exhaust gas temperature of the exhaust gas sensor or the catalyst.

摘要

A method and a device for forming a simulated signal of the temperature of the exhaust gas, exhaust gas sensor or catalytic converter for an internal combustion engine. Using a temperature characteristic depending on the air mass stream, and two low-pass filters with time constants depending on the air mass stream, the exhaust gas temperature upstream from the catalytic converter, the exhaust gas sensor temperature and the catalytic converter temperature are simulated. The air mass, integrated since the time the internal combustion engine is started, is compared with two threshold values to determine whether or not there is still condensation water present in the exhaust gas channel upstream from the catalytic converter and/or in the catalytic converter itself. If condensation water is present, the simulated temperature(s) is limited to a value of approximately 50 DEG to 60 DEG C. If the entire condensation water in the exhaust gas channel and/or in the catalytic converter was not evaporated during a short run of the internal combustion engine, or if the temperature of the internal combustion engine is extremely low when it is started, then extended times for evaporation of the condensation water are estimated and simulated by increased threshold values for the integrated air mass.