Air-fuel ratio characteristics are one of the significant indicators to measure the performance of precious metal-based three-way catalysts. The accuracy, timeliness and economy of their testing restrict the development of the highly-efficient catalysts to a certain extent. On the basis of low-cost laboratory simulation evaluation test, the work proposed a fully intelligent analysis method for air-fuel ratio characteristics using simulated annealing algorithm. The method can automatically identify the first mutation point with optimal O2 and CO concentration, and then calculate the locations of other mutation points. Meanwhile, the initial and real-time concentrations of NO, NO2, CO and other substances can be obtained. When the oxygen excess coefficient (λ) and A/F is calculated, the influence of the concentration of O2, NO, NO2 and CO on the air-fuel ratio has fully been considered. The results show that the intelligent method can obtain the same or even better results than the conventional manual data processing method, and the processing period of a single set of data will be reduced directly from 50 min to 0.2~2 s. |