Abstract: The emission regulations for light vehicles in China VI b require that the in use performance frequency (IUPR) of vehicles should not be less than 0.336. To meet this strict requirement, vehicle manufacturers need to model the IUPR rate before mass production to understand the changes rule in IUPR under different usage environments. This article proposes a comprehensive IUPR road validation method, aiming to make the validation results more closely related to the actual operation of in use vehicles. In addition, an in-depth analysis is conducted on the issue of low monitoring frequency discovered during the verification process, and effective improvement measures are proposed in the development stage to ensure that the in use monitoring frequency of vehicles after being put into market operation meets regulatory requirements.

Key words: light vehicles; diesel; IUPR

摘要： 轻型车国六 b 排放法规要求车辆的在用监测频率（IUPR）不得低于 0.336，为满足这 一严格要求，整车制造商在车辆量产前需要对 IUPR 率进行摸底，以了解车辆在不同使用环 境下 IUPR 的变化规律。文章提出了一种涵盖性广泛的 IUPR 道路验证方法，旨在使验证结果 更加贴近在用车实际运行情况。此外，还对验证过程中发现的监测频率偏低的问题进行了深 入分析，并在开发阶段提出了有效的改善措施，以保证车辆投入市场运行后的在用监测频率 满足法规要求。

关键词: 轻型车；柴油机；IUPR