中文摘要：

行驶周期是公交车排放预测的核心数据之一.本文采用便携式车载GPS收集了北京市14条公交线路重型柴油车的313 499条有效数据,并基于比功率分布方法,建立了北京市BRT公交、快速公交和常规公交车在低速区间、中速区间和高速区间的行驶周期,并对所建立的行驶周期进行了验证.结果表明：本文所建立的行驶周期与验证实测数据比功率分布的误差小于2％,而四工况的相对误差达5.7％,这表明本文建立的行驶周期更能准确地反映北京市公交车与排放相关的特征.

英文摘要：

The driving cycle is one key parameter for the vehicle emission estimation of transit buses.This paper collects a total of 313,499 data from heavy duty diesel vehicles of 14 transit lines using the portable GPS,by which different driving cycles for BRT,rapid transit buses,and regular transit buses are developed and validated for low,middle and high speed ranges based on the vehicle specific power （VSP）.It is found from the results that the RMSEs between VSP distributions of the developed driving cycles and the validation data sample is less than 2％,while RMSEs between VSP distributions of the Four-Mode driving cycle and the validation data sample are as much as 5.7％.It indicates that the developed driving cycles can estimate the emissions from the transit buses more accurately than the Four-Mode cycle.