| 摘要 |
PROBLEM TO BE SOLVED: To control the power supply to the heater of an air-fuel ratio sensor while taking into account the radiant heat which the air-fuel ratio sensor receives from a catalyst. SOLUTION: Heater power maps, in which the power to be supplied to a heater when the heater is affected by the radiant heat of a catalyst (new one) and the power to be supplied when it is not affected are calculated in accordance with operating conditions, are originated, and the difference between the power Q1ij to be supplied to the heater when it is affected by the radiant heat of the catalyst and the power Q2ij to be supplied to the heater when it is not affected by the radiant heat of the catalyst under the same operating condition, AQij =Q2ij -Q1ij , is calculated. Separately, the degree DR of degradation of the catalyst is calculated, and ΔQij is multiplied by a factor α calculated in accordance with the degree DR and is then subtracted from Q2ij to calculate the power Qij to be supplied to the heater; i.e., it is calculated by using Qij =Q 2ij -αx(Q2ij -Q1ij ). |
