直圆连接路段K型线与回旋线对比分析  

Comparative analysis of straight-curve connection road section K-curve and clothoid

作　　者：潘兵宏[1] 石蒙蒙 田鑫 PAN Bing-hong;SHI Meng-meng;TIAN Xin(School of Highway,Chang'an University,Xi'an 710064,Shaanxi,China)

机构地区：[1]长安大学公路学院,陕西西安710064

出　　处：《长安大学学报（自然科学版）》2024年第3期54-65,共12页Journal of Chang’an University(Natural Science Edition)

基　　金：陕西省交通运输厅科研项目(16-17K)。

摘　　要：为了从多个维度对比直圆连接路段回旋线与K型线的差异,分析对比K型线与回旋线在横向运动、侧倾运动和横摆运动3个自由度下的动力学差异,验证K型线作为缓和曲线的可行性的同时,研究分析车辆在基于K型线的直圆连接路段上的行车稳定性。利用K型线航向角特点,从微分和解析几何角度分析验证K型线和回旋线的曲率及曲率变化率状态。利用动力学软件CarSim对5种基于不同设计速度建立的道路模型进行仿真模拟,选取车辆横向加速度、车辆侧倾角、车辆横摆角及车辆方向盘转角4个指标作为评价依据,分析车辆在由2种不同缓和曲线连接的直圆连接路段上行驶时,其行车稳定性、驾驶人舒适性的状态差异。采用熵值法对各指标进行赋权,综合比较由K型线和回旋线连接的直圆路段的优劣。研究结果表明:K型线具有曲率及曲率变化率连续的优点;在设计指标相同条件下,K型线上车辆的各维度稳定参数均满足现有《公路路线设计规范》(JTG D20—2017)要求,且优于回旋线;随着设计速度的减小,K型线与回旋线之间的差异愈加明显,K型线在行车稳定性和舒适性方面的优势愈显著;在设计速度相同的前提下,K型线在驾驶稳定性、驾驶人行车舒适性方面整体优于回旋线;在设计速度较小时,K型线的优势更显著,可将K型线应用于设计速度较小的道路线形设计中,以保证并提高道路行车的稳定性及舒适性。In order to comprehensively compare the differences between clothoid and K-curve in straight-curve connection road sections from multiple dimensions,the dynamic differences was analyzed of K-curve and clothoid in three freedom degrees(lateral motion,tilt motion,and yaw motion).The feasibility of K-curve as transition curves was studied,while examining the vehicle's driving stability on straight-curve connection road sections based on K-curve.By leveraging the characteristics of the K-curve heading angle,differential and analytical geometry approaches was used to validate the states of curvature and curvature change rate for both the K-curve and the clothoid.Using the dynamics software CarSim,simulations were conducted on five road models based on different design speeds.Vehicle lateral acceleration,vehicle roll angle,vehicle yaw angle,and steering wheel angle were selected as evaluation criteria.The differences in vehicle stability and driver comfort were analyzed,when driving on straight-to-curve transition road segments connected by two different types of transition curves.The entropy method was employed to assign weights to each indicator,and a comprehensive comparison was made between the advantages and disadvantages of the straight-to-curve road segments connected by K-curves and clothoid.The results show that the K-curves exhibit the advantages of continuous curvature and curvature change rate.Under the same design criteria,all stability parameters of vehicles on K-curves meet the demand of Design Specification for Highway Alignment(JTG D20—2017) and outperform clothoid.As the design speed decreases,the differences between K-curves and clothoid become more pronounced,highlighting the superior performance of K-curves in terms of vehicle stability and comfort.The study proved that under the same design speed conditions,K-curves exhibit overall superiority in driving stability,and driver comfort compared to clothoid.Particularly at lower design speeds,the advantages of K-curves become more pronounced.Therefo

关 键 词：道路工程 路线设计 曲线设计 K型线 仿真模型 行车稳定性 

分 类 号：U412.34[交通运输工程—道路与铁道工程]