Exhaust gas temperature determination and oxygen sensor heater control

摘要

A method and apparatus determine exhaust gas temperature and control the heater of a heated exhaust gas oxygen sensor. Heater failures are diagnosed based on the level of current flowing through the heater. Exhaust gas temperature is determined by using a Kalman filter. The exhaust gas temperature sensor is eliminated while maintaining a high degree of accuracy. Current flowing through the heater is used to calculate the temperature of the heater. The temperature of the heater is compared to a desired temperature range and the current to the heater is adjusted to maintain the desired temperature range.