Patent ID: 6970800

Claim:
A method of predicting exhaust gas temperature at a catalytic converter inlet of an engine at a time of engine restart, wherein the exhaust gas temperature at the catalytic converter inlet of the engine is predicted based on a stored exhaust gas temperature at the time of engine shut-off and an elapsed time between the engine shut-off and the engine restart, wherein the exhaust gas temperature at the catalytic converter inlet of an engine at the time of engine restart is predicted by the following model: EGT â€” CAT â€” ST= ( EGT â€” CAT _OFFâˆ’ INT )* K 1 +INT wherein EGT_CAT_ST is an initial exhaust gas temperature at the catalytic converter inlet when the engine is restarted; EGT_CAT_OFF is the exhaust gas temperature at the catalytic converter inlet when the engine is previously turned off; K 1 is a time factor determined according to an elapsed time; and INT is an intake temperature when the engine is restarted.