Abstract: Emission limits for heavy diesel vehicles and measurement methods GB 17691－2018 set out the monitoring requirements for on-board diagnostic's (OBD) in-use performance ratio (IUPR) for heavy commercial diesel vehicles. The IUPR rates for different manufacturers, models and mileage belonging to the same OBD family are required to meet the regulatory requirements. The results show that engine exhaust temperature, exhaust volume flow rate and exhaust mass flow rate are the key factors affecting the diagnostic release of OBD. Through the method of orthogonal test, this paper analyzes the influence of the boundary between the back pressure, intake resistance and middle cold pressure drop of different manufacturers on exhaust temperature, volume flow of exhaust gas and mass flow of exhaust gas, identifies the influence weight and rule, explores the key technical indicators of vehicle matching, and provides standards for the subsequent vehicle matching.

Key words: IUPR; Exhaust temperature; Exhaust gas volume flow rate; Exhaust gas mass flow rate

摘要： 重型柴油车污染物排放限值及测量方法 GB 17691—2018 中对于重型商用柴油车提出了 车载诊断系统（OBD）实际监测频率（IUPR）的监测要求，属于同一 OBD 系族的不同厂家、 不同车型、不同里程的 IUPR 率要满足法规要求。研究表明发动机排气温度、废气体积流量 和废气质量流量是影响 OBD 诊断释放的关键因素。文章通过正交试验的方法，分析不同厂家 整车匹配的背压、进气阻力与中冷压降的边界对排温、废气体积流量以及废气质量流量的影 响，识别影响权重及规律，探索整车匹配关键技术指标，对后续的整车匹配提供标准。

关键词: IUPR；排气温度；废气体积流量；废气质量流量