汽油机极限催化器故障诊断及选型方法研究

Researchon Fault Diagnosis and Selection of Limited Catalytic Converter on Gasoline Engine EMS

催化器在整车排放改善中起着非常重要的作用,由于其性能优劣直接影响车辆排放结果,催化器故障诊断成为汽油机EMS车载诊断(OBD)的重要诊断之一.本文通过分析催化器故障诊断系统工作原理,实现了基于Simulink的极限催化器储氧能力(OSC)故障诊断方法,通过大量试验得到催化器储氧时间极限限值,同时也分析了极限催化器和老化催化器储氧时间符合正态分布规律.该诊断方法在整车上进行验证,实验结果表明诊断策略稳定可靠,在排放超标之前精确报故障.

Catalytic converter plays a very important role in the improvement of vehicle emissions,due to its performance directly affects the results of vehicle emissions,the fault diagnosis of the catalytic converter is one of the most important diagnostic methods of EMS(OBD).This paper analyzes the working principle of the fault diagnosis system of catalytic converter,and realizes the Oxygen Storage Capacity(OSC)fault diagnosis methodbased on simulink;oxygen storage time of limited and aged catalytic are acquired via a lot of experiments,and the oxygen storage time conform to the law of normal distribution.The diagnosis method is verified on the whole vehicle,and the experimental results show that the diagnosis method is stable and reliable,and the fault can be accurately reported before the emission is exceeded.