基于流场的车辆换道轨迹规划方法

发布时间：2018-06-28 16:24

本文选题：换道轨迹模型 + 安全性判定　；参考：《燕山大学》2016年硕士论文

【摘要】：换道是车辆的主要驾驶行为之一,由于车辆换道过程中更易发生事故,所以换道安全性已成为国内外的研究重点,换道安全性包括车辆稳定性和不发生碰撞两方面内容,本文将综合考虑两方面内容,根据换道轨迹模型判定换道安全性并得到车辆最终换道轨迹,最后进行仿真分析。目前,国内外关于车辆换道模型研究很多,如三角函数换道模型、圆弧模型、等速偏移模型、期望加速度模型等。上述换道轨迹模型计算较为繁琐,且安全性判定方法较为单一,准确性差。因此,本文将提出一种新的换道轨迹模型能够实时判定车辆的换道安全性。首先,本文对车辆外流场分布进行CFD模拟计算,根据计算结果可知车辆速度外流场影响区域及速度场数据,随后运用DS证据理论对归一化的车辆外流场横、纵向速度数据进行融合,判断数据场中各单元的安全程度,并设定出车辆行驶的安全域。其次,本文提出一种新的5次多项式换道轨迹模型,以车辆操纵稳定性为优化目标,利用蚁群算法求解相关变量,确定了最优换道轨迹模型,并运用加权证据理论融合车辆安全域数据及相对行驶轨迹倾斜角,对车辆换道安全性进行了判定。最后,以换道车辆车速为30m/s时安全换道为例对车辆安全性判定结果进行了仿真分析,并对车辆换道时的突发情况进行了简单分析,给出了相应的应对策略。通过研究分析,本文提出的多项式换道轨迹模型曲率连续、计算简单、适应性强,可以实时判定车辆换道安全性,实现车辆换道轨迹的实时更新,为车辆安全换道提供了理论依据。
[Abstract]:The change of lane is one of the main driving behaviors of the vehicle. Because the accident is more likely to occur in the course of the change of the vehicle, the safety of the change of course has become the focus of the research at home and abroad. The safety of the change of course includes two aspects: the stability of the vehicle and the non-collision. In this paper, two aspects will be considered synthetically, according to the change track model to judge the safety of the change of track and get the final track of the vehicle, and finally carry on the simulation analysis. At present, there are a lot of researches on vehicle change model, such as trigonometric function change model, circular arc model, isokinetic migration model, expected acceleration model and so on. The calculation of the trajectory model is complicated, and the method of safety determination is simple and the accuracy is poor. Therefore, this paper proposes a new trajectory model which can determine the safety of the vehicle in real time. Firstly, CFD simulation is carried out on the distribution of vehicle outflow field. According to the calculated results, the influence area and velocity field data of vehicle velocity outflow field are obtained, and then the normalized vehicle outflow field is transverted by DS evidence theory. The longitudinal velocity data are fused to judge the safety degree of each unit in the data field and the safety range of vehicle driving is set up. Secondly, this paper presents a new 5-order polynomial trajectory model, which takes the vehicle handling stability as the optimization objective, and uses ant colony algorithm to solve the related variables, and determines the optimal trajectory model. The weighted evidence theory is used to combine the data of vehicle safety domain and the angle of relative track inclination to determine the safety of vehicle change. Finally, the result of vehicle safety determination is simulated and analyzed when the vehicle speed is 30m/s, and the emergency situation is simply analyzed, and the corresponding countermeasures are given. Through research and analysis, the polynomial trajectory model proposed in this paper has the advantages of continuous curvature, simple calculation and strong adaptability. It can determine the safety of vehicle change in real time and realize the real-time updating of vehicle track change. It provides a theoretical basis for the safe change of vehicle lanes.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U491

【相似文献】