基于实际工况和运行载荷的城市公交传动参数优化研究

摘要

In view of the issue that the mismatching between driving condition and powertrain gear ratio parameters affects vehicle's fuel economy,the actual running data of city buses running over 100 000 km was collected.According to the data,10 feature parameters reflecting the bus route running characteristics are put forward,and the bus driving conditions are created on the basis of kinematics.The deviation is within 3％ relative to the real road condition statistical characteristic parameters.The testing design method of Latin hypercube sampling (LHS) was adopted to optimize the powertrain gear ratio parameters,and build a GT-SUITE vehicle performance simulation model considering the driving conditions and vehicle average load state to confirm the best transmission ratio parameter taking the dynamic property design index as the constraint condition.Result shows it is feasible to realize the improvement of bus fuel economy on the basis of the driving conditions and bus transmission ratio parameters relying on real load optimization.The fuel consumption was decreased by 2.76％ compared with that of the bus with original configuration.%针对实际运行工况与传动比参数不匹配导致公交车燃油经济性变差的问题,采集超过10万km的实车运行数据,从中提出了10个反映线路运行特点的特征参数,基于运动学片段构建了公交特征工况,与实际路况统计特征参数相对偏差在3％以内.采用拉丁超立方抽样的试验设计方法,以发动机工况点在万有特性MAP经济区域分布比例最大为优化目标,建立基于工况和载荷状态的GT整车性能仿真模型,以动力性设计指标为约束条件,确定最佳的传动比参数.结果表明,基于运行工况和实际载荷优化公交车传动比参数,实现车辆燃油经济性改善是可行的,油耗比原车降低了2.76％.