基于GM跟驰模型的内河限制性航道船舶交通流基本图

Fundamental diagram of vessel traffic flow in inland restricted waterway based on GM following model

为准确掌握内河航道上船舶交通流的运行特征与规律,考虑船舶正常航行时为保持舵效所需的最低航速与最小安全间距,引入最低航速和最大密度2个特征变量,对经典的GM跟驰模型进行局部修正,然后根据锡澄运河现场实船跟驰实验数据,回归拟合了内河船舶交通流的3种速度间距关系,从而构建了新的内河限制性航道船舶交通流基本图模型.结果表明,所提出的船舶交通流基本图模型符合实际,指数模型和对数模型检验的MAPE值小于5%,RMSE值小于0.4,R^(2)值大于0.93.该基本图模型是对经典车辆交通流基本图模型的局部拓展,使之既有交通流的普遍规律,又符合内河船舶的航行特点,建议采用指数模型或对数模型描述内河限制性航道船舶交通流基本图.

To understand accurately the operating characteristics and laws of vessel traffic flow in inland waterway,considering the minimum speed and the minimum safe spacing of vessels required to maintain the rudder effect during normal sailing,the minimum speed and the maximum density of inland vessel traffic flow were introduced as characteristic variables to modify the classical general motor(GM)car-following model.Three kinds of relationships of speed-spacing of inland vessel traffic flow were fitted according to the field data of vessel-following experiments in Xicheng Canal,China.A new fundamental diagram model(FDM)was established for vessel traffic flow in the inland restricted waterway.The results show that the new FDM for vessel traffic flow is in good agreement with the field data.The values of MAPE and RMSE tested by the exponential model and the logarithmic model are less than 5%and 0.4,respectively,and the value of R^(2) is greater than 0.93.The new FDM,which follows the general law of traffic flow,is a partial extension of the classical FDM for vehicle traffic flow to match the navigational characteristics of inland vessel.It is suggested that the exponential model or the logarithmic model can be adopted to describe the FDM of vessel traffic flow in inland restricted waterway.