Device and method of controlling exhaust gas sensor temperature, and recording medium for exhaust gas senso rtemperature control program

摘要

A sensor temperature control means ( 18 ) for controlling the temperature of an active element ( 10 ) of an exhaust gas sensor (O₂ sensor) ( 8 ) disposed in an exhaust passage ( 3 ) estimates the temperatures of the active element ( 10 ) and a heater ( 13 ) based on an element temperature model which is representative of a temperature change of the active element due to heat transfer between the active element ( 10 ) and the heater ( 13 ) which heats the active element and heat transfer between the active element ( 10 ) and an exhaust gas, and a heater temperature model which is representative of a temperature change of the heater due to heat transfer between the active element ( 10 ) and the heater ( 13 ) and the supply of electric power to the heater ( 13 ), and controls the heater ( 13 ) to equalize the temperature of the active element ( 10 ) or the heater ( 13 ) with a predetermined target temperature using estimated values of the temperatures. It is possible to accurately estimate the temperature of the active element ( 10 ) of the exhaust gas sensor ( 8 ) or the heater ( 13 ), and control the temperature of the active element ( 10 ) of the exhaust gas sensor ( 8 ) stably at a desired temperature using an estimated value of the temperature.