针对车用柴油机NOx排放控制SCR系统中VWT-、Cu-、Fe-SCR催化器，在车辆行驶过程中可能出现多种失效形式，以催化器热失效/化学中毒为研究对象，制备不同失效程度样件，获得失效状态下的催化器微观结构表征参数，通过试验研究构建催化剂性能及储氨特性与各参数之间关系，建立催化剂失活状态下的数学模型、动力学模型、数值仿真模型及控制模型，实现催化器失效的数值仿真研究，构建催化器失效机理；建立催化剂储氨能力模型及储氨量估计模型，催化剂储氨能力与催化剂性能之间数学模型；研究催化剂不同失活程度对发动机排放影响规律，对比研究几种典型诊断方法及容错控制方法，寻找适用于车载条件的故障诊断方法及容错控制方法，突破现有车载诊断系统的局限性，实现催化器失效状态下的污染物排放最优控制，形成“催化器失效机理-故障诊断-容错控制”系统的理论、技术及方法，为Urea-SCR系统的推广应用提供理论依据及技术支撑。

VWT-,Cu-,Fe-based catalytic converter of NOx emission after-treatment system for automotive diesel engine(Urea-SCR system) may have a variety of failure modes in the process of driving. With catalyst thermal inactivation/chemical poisoning as the research object, prepare different degree of failure samples, get microstructure characterization parameters of catalytic converters in the failed state, build the relationship between catalyst performance, ammonia storage characteristics and parameters of the experimental study, establish mathematical model, kinetic model, numerical simulation model and control model under catalyst deactivation state, realize numerical simulation of catalytic converter failure, and build catalytic converter failure mechanism; establish the ammonia storage capacity model and ammonia quantity estimation model of catalyst converter, and mathematical model between ammonia storage capacity and catalyst performance; study influence law of different inactivation degree of catalyst on engine emissions, compare and study several typical diagnostic methods and fault-tolerant control methods, look for fault diagnosis methods and fault-tolerant control methods for in-vehicle conditions, break through the limitations of the existing board diagnostic systems, realize optimal control of pollutant emissions under the state of catalytic converter failure, form theory and technical methods of the catalytic converter failure mechanism - fault diagnosis - fault-tolerant control system, and provide a theoretical basis and technical support for the promotion and application of Urea-SCR system.