Application of the support vector machine and heuristic k-shortest path algorithm to determine the most eco-friendly path with a travel time constraint

This study aims to determine an eco-friendly path that results in minimum CO₂ emissions while satisfying a specified budget for travel time. First, an aggregated CO₂ emission model for light-duty cars is developed in a link-based level using a support vector machine. Second, a heuristic k-shortest path algorithm is proposed to solve the constrained shortest path problem. Finally, the CO₂ emission model and the proposed eco-routing model are validated in a real-world network. Specifically, the benefit of the trade-off between CO₂ emission reduction and the travel time budget is discussed by carrying out sensitivity analysis on a network-wide scale. A greater spare time budget may enable the eco-routing to search for the most eco-friendly path with higher probability. Compared to the original routes selected by travelers, the eco-friendly routes can save an average of 11% of CO₂ emissions for the trip OD pairs with a straight distance between 6 km and 9 km when the travel time budget is set to 10% above the least travel time. The CO₂ emission can also be reduced to some degree for other OD pairs by using eco-routing. Furthermore, the impact of market penetration of eco-routing users is quantified on the potential benefit for the environment and travel-time saving.     

汽车紧急制动响应的分析

汽车紧急制动时,制动力矩、制动减速度、车速、车体俯倾角及其角加速度与时间呈非线性关系。本文对BJ212轻型越野汽车满载紧急制动进行了试验,以试验结果为依据,讨论了汽车紧急制动时诸参数之间的关系。其结论是:在瞬变过程中,制动减速度及车体俯倾角加速度与其制动初速度无关;在平稳过程中,制动减速度及车体俯倾角加速度随制动初速度增大而减小,而且大致成线性关系。     

汽车检测诊断新技术的应用

认为：随着电子技术和传感技术的进步，汽车诊断技术及设备发展非常迅速，在实行技术状况临测、不解体诊断、视情维修、强化管理等方面起着重要作用。重点介绍了功率平衡、点火系统、气缸、燃油供给系及起动系的检测诊断的方法、项目和设备。     

汽车列车横向稳定性研究

汽车列车是牵引汽车与挂车相互作用、相互耦合的复杂系统,其横向稳定性研究涉及多体动力学、刚柔耦合力学、气体动力学、车辆非线性运动和电子控制等多个学科.本文论述了汽车列车横向稳定性的国内外研究现状、研究方法和试验手段,探讨了使用参数和结构参数对汽车列车横向稳定性的影响,分析了角阶跃输入下汽车列车侧向加速度响应.最后,对汽车列车动力学数字仿真算法及代表性软件进行了分析阐述.     

A semi-empirical dynamic tire model for combined-slip forces

This article presents a semi-empirical combined-slip tire model including transient behavior. It is assumed that the transient behavior is a result from the dynamic deformation of the tire carcass and that the interaction between the lateral and longitudinal slip, and forces can be explained by the deformation of the rubber treads. The deformation of the tire carcass makes the tread slip deviate from the wheel-rim motion in a way that may be described by differential equations. A method based on brush-model tire mechanics is used to construct the combined-slip forces as nonlinear scalings of corresponding pure-slip forces.     

车辆混合动力传动系统开发现状与展望

本文通过对车辆动力传动系统能量分配型式及特点的分析，提出在市区公共汽车等车辆上使用具有良好综合性能的混合动力传动系统。并对各种型式的车辆混合动力传动系统的研究现状进行了分析与总结，展望了未来的发展趋势，对以后的研究，开发具有指导意义。     

行驶车辆振动信号的小波分析

本文介绍了小波分析的理论方法，并上小波分析方法应用到了行驶车辆振动的分析中，即：通过二进离散小波变换，把实际振动信号进行多层小波分解，使异常信号和非平稳高频信号得到良好的时间定位和图形显示，并把信号的路面激励与本体振动分离开来。     

汽车碰撞试验中模拟和数字滤波器的实现

滤波是数据采集和处理的一种常用技术手段，本文就汽车碰撞试验中有关滤波的问题进行探讨，用冲激响应不变法实现了满足通道频率特性要求的实用算法，为了消除相位误差采用正反向二次滤波的方法，但它会引起幅频特性改变，并对此提出了修正的方法。     

稳态条件下用于车辆动力学分析的轮胎模型

本文对稳态条件下可用于车辆动力学分析的轮胎理论模型和半经验模型,包括纵滑侧偏特性、纯纵滑特性和纯侧偏特性模型,进行了综合与分析,并讨论了各种模型间的相互关系。为车辆动力学分析提供了具体的轮胎模型和选用依据。     

汽车台架试验系统机械惯量电模拟方法

本文探讨了汽车台架试验系统中惯量电模拟技术的构成及其技术上的特点，提出通过改变调速系统的各种给定输入，来达到试验系统与实际系统的惯量拟合，文中导出了给定输入变化规律，并以汽车同步器台架试验系统为例，进行了仿真及优化计算。