With the acceleration of urbanization process, the country’s strong support for the healthy development of the logistics industry has made urban logistics become a hot topic in recent years. With the increase in the number of logistics vehicles, traffic accidents have become more frequent. Intelligent vehicle collision avoidance system is an important part of advanced safety technology. To increase veracity and practicability of logistics vehicle safety collision avoidance, this paper presents a safety distance model for longitudinal collision avoidance of logistics vehicles considering road slope and road adhesion coefficient. Based on the vehicle kinetic theory, the information of surrounding environment for the vehicle is obtained using environment sensing system adequately, a method is designed to estimate the road slope and road adhesion coefficient. Combined with vehicle dynamics and tire normal force variation, the road slope was estimated. Based on the relationship between slip rate and adhesion coefficient, the Least Square Method is used for multivariate fitting to obtain the relationship between rolling resistance coefficient and road adhesion coefficient, estimate the road adhesion coefficient, and the maximum deceleration of vehicle braking is modified. Therefore, the safety distance model is established. In order to verify the accuracy and effectiveness of the model, three cases are designed for verification: case I is verification of the safety distance model considering the slope factor; case II is verification of the safety distance model considering the road adhesion factor; case III is the safety distance verification considering both the factors of slope and road adhesion coefficient. The result shows that it is necessary to take the factors of road slope and adhesion coefficient into the safety distance model to improve the accuracy of the model.

中文翻译：

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考虑坡度和道路附着系数的物流车辆纵向避碰安全距离模型

随着城市化进程的加快，国家对物流业健康发展的大力支持，使得城市物流成为近年来的热门话题。随着物流车辆数量的增加，交通事故也越来越频繁。智能车辆防撞系统是先进安全技术的重要组成部分。为提高物流车辆安全避撞的准确性和实用性，提出一种考虑道路坡度和道路附着系数的物流车辆纵向避撞安全距离模型。基于车辆动力学理论，充分利用环境感知系统获取车辆周围环境信息，设计了一种估计道路坡度和道路附着系数的方法。结合车辆动力学和轮胎法向力变化，估计道路坡度。根据滑移率与附着系数的关系，采用最小二乘法进行多元拟合，得到滚动阻力系数与道路附着系数的关系，估计道路附着系数，修正车辆制动的最大减速度。因此，建立了安全距离模型。为了验证模型的准确性和有效性，设计了三个案例进行验证：案例一是考虑斜率因子的安全距离模型的验证；案例二为考虑道路附着系数的安全距离模型验证；案例三是同时考虑坡度和道路附着系数的安全距离验证。结果表明，需要将道路坡度和附着系数等因素纳入安全距离模型，以提高模型的精度。