北京地区第五阶段在用轻型车OBD监测频率的特征分析

随机采集北京地区200辆满足第5阶段排放标准在用车的车载诊断系统（OBD）的IUPR（OBD监测频率）数据，测试了4种典型车系的在用车在实际道路行驶工况下IUPR各监测项的特征分布，并和NEDC工况下的实验结果进行对比.结果表明：采集数据车辆的OBD系统均能实现对催化器和氧传感器的监控，对EGR和次级氧传感器的监控也可分别达到74%和91%；在用车平均点火循环3.9次才能满足一次目前IUPR的监测条件；各监测项IUPR均值均远大于国五标准限值0.10，但各IUPR监测值分布存在差异，催化转化器和氧传感器的达标率均为92%；实验室NEDC模拟工况基本能实现对各车系机动车尾气排放控制的监测，但4条实际道路测试结果则表明不同车系IUPR监测项分子+1的差异较大；拥堵路况的低速工况下OBD系统难以实现对车辆尾气排放控制系统各监测项的有效监测.因此，需结合北京实际路况进一步完善在用车辆OBD系统的监测条件，实现对北京在用车尾气排放控制系统的有效监控.

Investigation on OBD monitoring frequency characteristics of China V in-use LDV in Beijing.

The IUPR (OBD monitoring frequency) data of 200 in-use China V cars were randomly collected in Beijing. And the characteristic distributions of the IUPR monitoring values were tested by driving four kinds of typical cars on actual road, then the results were compared with experimental tests under New European Driving Cycle (NEDC). The results showed that the catalytic converter and oxygen sensor of OBD system could be monitored for collection vehicle, and the monitoring rates of EGR and secondary oxygen sensor could reach 74% and 91%respectively. At present, 3.9timesignition cycles could meet an IUPR monitoring conditions on average. The IUPR average values for each monitoring items were far greater than the China V limit value of 0.10. However, there were some differences for monitoring value distribution. Catalytic converter and oxygen sensor monitoring rates were both 92%. And the monitoring of the vehicle emissions could be realized basically under indoor NEDC, but the test results on 4 actual road indicated that different vehicles had different IUPR monitoring results for molecule adding 1. OBD system was difficult to achieve effective monitoring of vehicle exhaust emission for the traffic jams and low speed. Therefore, it is necessary to combine the actual conditions in Beijing to further improve the monitoring conditions of the vehicle OBD system, and the effective control of the vehicle emission control system will be achieved in Beijing.