基于后氧传感器信号的催化器诊断方法应用

摘要

On a vehicle with 1 .4 L naturally aspirated and China Ⅴ gasoline engine ,the application of three-way catalyst diag-nostic method based on the rear oxygen sensor signal was researched .The experimental results show that the oscillation fre-quency and amplitude of rear oxygen sensor signal increase with the decrease of oxygen storage capacity of catalyst .The aver-age and standard deviation of oxygen storage capacity loss increase with the decrease of the cutoff frequency of high-pass filte-ring and the optimal cutoff frequency is 0 .2 .The catalyst diagnostic method can finally detect the failure of three-way catalyst by optimizing all diagnostic parameters .%在一搭载1.4L自然吸气汽油发动机且满足国Ⅴ排放法规的汽车上 ,开展了基于后氧传感器信号的三效催化转化器诊断方法应用研究.试验结果表明 :随着三效催化转化器储氧能力的下降 ,后氧传感器信号的振动频率及幅值增大 ;三效催化转化器储氧能力损失平均值及标准偏差随着高通滤波截止频率的减小而增大 ,最优截止频率为0.2 ;通过合理优化各诊断参数 ,该诊断方法能有效地监测出三效催化转化器的失效.