Patent ID: 6823839
Filing Date: 2004-11-30
Classification: G05D

Abstract:
An apparatus for controlling the temperature of an exhaust gas sensor disposed in an exhaust passage of an internal combustion engine and having an active element for contacting an exhaust gas flowing through the exhaust passage and a heater for heating the active element, said apparatus comprising:exhaust gas temperature estimating means for sequentially estimating the temperature of the exhaust gas flowing through the exhaust passage, using at least a parameter representative of an operating state of said internal combustion engine; and heater control means for controlling said heater to equalize the temperature of the active element of said exhaust gas sensor with a predetermined target temperature, using an estimated value of the temperature of the exhaust gas from said exhaust gas temperature estimating means; wherein said exhaust gas temperature estimating means comprises means for sequentially estimating the temperature of the exhaust gas in the vicinity of an exhaust port of said internal combustion engine based on the parameter representative of the operating state of said internal combustion engine, and estimating the temperature of the exhaust gas in the vicinity of the location of said exhaust gas sensor, using at least an estimated value of the temperature of the exhaust gas in the vicinity of the exhaust port and data representative of the speed of said exhaust gas.