DEGRADATION DEGREE ESTIMATION SYSTEM

原文（中国語）

A degradation degree estimation system includes: an airflow meter; a three-way catalyst; an air-fuel ratio sensor; an NOx sensor; and an estimation device that estimates a degree of degradation of the three-way catalyst. The estimation device includes: an acquisition unit that acquires a detected rich air-fuel ratio that is a detected air-fuel ratio detected by the air-fuel ratio sensor when the detected air-fuel ratio indicates a rich air-fuel ratio, a detected intake air amount detected by the airflow meter, and a detected ammonia amount detected by the NOx sensor; and an estimation unit that estimates the degree of degradation based on the detected rich air-fuel ratio, the detected intake air amount, and the detected ammonia amount, the estimation unit estimating a higher degree of degradation as the detected ammonia amount is smaller with respect to the detected rich air-fuel ratio and the detected intake air amount.