钟建伟,吴兴龙

泛亚汽车技术中心有限公司，上海201201

摘要：分析氧传感器劣化失效对三元催化器诊断的影响，发现前氧信号响应劣化导致三元催化器诊断计算的储氧时间变小，易导致将正常误判为故障；后氧信号响应劣化导致三元催化器诊断计算的储氧时间变大，易导致将故障误判为正常。引入前、后氧补偿值对实测储氧时间进行修正,设计基于氧传感器劣化的三元催化器诊断策略。试验表明，该策略可实现前后氧传感器劣化的偏差补偿，提高对三元催化器诊断的精确性。

关键词：氧传感器劣化；三元催化器诊断；氧传感器响应

Abstract:The effect of oxygen sensor degradation on the diagnosis of three way catalytic converter (TWC) is analyzed. It is found that the degradation of pre oxygen sensor leads to the decrease of oxygen storage time of TWC, which tends to misjudge the normal TWC as fault; while the deterioration of post oxygen sensor leads to the increase of oxygen storage time of TWC, which tends to misjudge the actual fault TWC as normal. The measured oxygen storage time is corrected by introducing the pre and post oxygen compensation values, and the diagnosis strategy of TWC based on the deterioration of oxygen sensor is designed. Experimental results show that the strategy can realize the deviation compensation of the deterioration of the pre and post oxygen sensors, and improve the accuracy of the TWC diagnosis.

Keywords:oxygen sensor degradation; TWC diagnostic; oxygen sensor response