考虑后车不同初始状态的安全距离模型  

Research on the safety distance model considering different initial states of rear vehicles

作　　者：李清清 简晓春[1] 吴胜利[1] 高晨莹 LI Qingqing;JIAN Xiaochun;WU Shengli;GAO Chenying(College of Traffic and Transportation,Chongqing Jiaotong University,Chongqing 400074,China)

机构地区：[1]重庆交通大学交通运输学院,重庆400074

出　　处：《重庆理工大学学报（自然科学）》2023年第3期69-76,共8页Journal of Chongqing University of Technology：Natural Science

基　　金：国家自然科学基金项目(51705052)。

摘　　要：传统安全距离模型主要依靠车辆间运动学关系建立,且后车接收预警信号时的初始状态常被视为匀速行驶,导致模型精度不高、普适性差,影响前向碰撞预警系统可靠性。针对以上问题,考虑了后车不同初始状态,结合运动学与动力学方法综合分析车辆制动过程,进行纵向动力学建模,根据前车运动状态建立安全距离模型,通过仿真试验得出后车不同初始状态下预警安全距离的差异及变化规律。仿真结果表明:后车初始加/减速状态和初始匀速状态的预警安全距离存在差异,差异大小与后车初始加/减速度值、行驶速度有关,且前车处于制动工况时差异尤为显著,预警安全距离的差值最大可达18.69 m,相对变化率达到49.53%。考虑后车不同初始状态的安全距离模型更加符合实际情况,可有效提高预警系统对车辆安全状态判断的准确性。Establishing an accurate and reasonable evaluation model of driving safety status is one of the key technologies of the forward collision warning system.As the most classical evaluation model of driving safety status,safe distance has the advantages of universality and robustness.However,traditional safety distance models often assume the initial state of the rear car receiving the warning signal as uniform motion and rely solely on the analysis of vehicle kinematics to determine the safety distance.Due to the complex force situation and multiple influencing factors during vehicle braking,analyzing braking distance only from a kinematic perspective may reduce the accuracy of the model and thus affect the reliability of the warning system.To address these issues,this paper considers three different motion states of the rear car,including initial uniform motion,acceleration,and deceleration.Combining kinematics and dynamics methods,the force situation of a vehicle during each stage of the braking process is comprehensively analyzed for different initial states of the rear car.Longitudinal dynamic modeling is then conducted to establish safety distance models based on the front car’s stationary state,uniform or accelerated motion state,and emergency braking state.Simulation experiments are carried out to obtain the differences and variation patterns of the warning safety distance under different initial states of the rear car.The simulation results show that there are differences in the warning safety distance for the following vehicle’s initial acceleration/deceleration state and initial uniform motion state,and the difference size is related to the initial acceleration/deceleration value and driving speed of the following vehicle.The difference in the warning safety distance generated by different initial states of the following vehicle increases with an increase in the initial acceleration/deceleration value,with a distance difference of the front vehicle’s braking condition being the most significant of up

关 键 词：前向预警系统 安全距离模型 初始状态 动力学建模 

分 类 号：U461[机械工程—车辆工程]