汽车电路图的识读方法

针对维修电工在从事汽车电子电器维修过程中对汽车电路图识读存在的问题,以帕萨特1．8GSI（2005年款）汽车电路为例,介绍了汽车电路图的组成,通过回路原则将电路简化,让维修电工充分熟悉整车电路图,并能迅速准确地根据汽车电路图找出故障并排除。     

电动汽车轮毂电机车轮动力系统的研究

目前,电动汽车研制的难点之一是传统电动机的转矩不够大,不得不使用变速机械来满足电动汽车起动和爬大坡的大转矩需求。本技术方案就是使用高于传统电动机常规电压的宽范围系列阶梯电压来驱动特制的轮毂电机车轮动力系统,以彻底解决当前研制电动汽车的这一难点,从而使现代电动汽车能早日大量使用,造福于人类。     

Automatic calibration of fundamental diagram for first‐order macroscopic freeway traffic models

Despite its importance in macroscopic traffic flow modeling, comprehensive method for the calibration of fundamental diagram is very limited. Conventional empirical methods adopt a steady state analysis of the aggregate traffic data collected from measurement devices installed on a particular site without considering the traffic dynamics, which renders the simulation may not be adaptive to the variability of data. Nonetheless, determining the fundamental diagram for each detection site is often infeasible. To remedy these, this study presents an automatic calibration method to estimate the parameters of a fundamental diagram through a dynamic approach. Simulated flow from the cell transmission model is compared against the measured flow wherein an optimization merit is conducted to minimize the discrepancy between model‐generated data and real data. The empirical results prove that the proposed automatic calibration algorithm can significantly improve the accuracy of traffic state estimation by adapting to the variability of traffic data when compared with several existing methods under both recurrent and abnormal traffic conditions. Results also highlight the robustness of the proposed algorithm. The automatic calibration algorithm provides a powerful tool for model calibration when freeways are equipped with sparse detectors, new traffic surveillance systems lack of comprehensive traffic data, or the case that lots of detectors lose their effectiveness for aging systems. Furthermore, the proposed method is useful for off‐line model calibration under abnormal traffic conditions, for example, incident scenarios. Copyright © 2015 John Wiley & Sons, Ltd.     

High-speed trains subject to abrupt braking

The dynamic response of high-speed train subject to braking is investigated using the moving element method. Possible sliding of wheels over the rails is accounted for. The train is modelled as a 15-DOF system comprising of a car body, two bogies and four wheels interconnected by spring-damping units. The rail is modelled as a Euler–Bernoulli beam resting on a two-parameter elastic damped foundation. The interaction between the moving train and track-foundation is accounted for through the normal and tangential wheel–rail contact forces. The effects of braking torque, wheel–rail contact condition, initial train speed and severity of railhead roughness on the dynamic response of the high-speed train are investigated. For a given initial train speed and track irregularity, the study revealed that there is an optimal braking torque that would result in the smallest braking distance with no occurrence of wheel sliding, representing a good compromise between train instability and safety.     

基于UML工作流模型的应用研究

分析了工作流模型的组成,根据统一建模语言的特点,形式化定义了为工作流过程建模的UML活动图结构以及建模规则,给出一个应用实例来描述建模过程并对模型作了详细分析。     

并联混合动力汽车扭矩管理的模糊控制与仿真

并联混合动力汽车中内燃机和电机之间存在动力的耦合和分离过程,能量管理策略比较复杂。为了进一步合理分配内燃机和电机的动力输出,增强其能量管理策略的鲁棒性,文中分析了电辅助控制策略的不足,提出了基于模糊逻辑控制的包含驾驶员扭矩识别和蓄电池功率平衡的并联混合动力汽车扭矩分配策略,并利用ADVI SOR2002的仿真环境,完成了该模糊逻辑扭矩控制模块的仿真。结果表明,模糊逻辑控制策略满足控制目标,对提高汽车的动力性和燃油经济性、改善排放、保证蓄电池的充放电功率平衡有明显的作用。     

汽车转向器在线检测设备的研制

以汽车转向器在线检测设备为研究对象,介绍其硬件组成、工作原理和软件设计,阐述在调试过程中数据处理方法和程序控制技巧,以及如何实现检测高效率和自动控制.     

A ductile tearing assessment diagram for cracked circular-hollow-section joints under reversed loadings

This paper proposes a ductile tearing assessment diagram (TAD) to predict the load resistance to the crack extension relationship during the stable tearing process of the circular-hollow-section (CHS) joints under the reversed in-plane bending actions. The tearing assessment diagram utilizes the envelope of the load-deformation curve from the fracture test under reversed loadings to build the connection among the fracture resistance, load resistance and crack extension. To verify the proposed approach, this study performs fracture experiments, imposing the reversed in-plane bending on the CHS X-joints, made of Q345 steel, with a surface crack near the weld toe. The experimental investigation reveals the effect of the reversed loading on the fracture resistance and validates the TAD-based assessment for tubular joints. Meanwhile, this study performs the cyclic fracture test on the single-edge-notched-tension [SE(T)] specimen made of Q345 steel and derives the TAD from the experimental record of the SE(T) specimen. The specimen-based assessment successfully predicts the load versus crack extension relation for the reported joints under reversed loadings. The study provides a basic framework to predict the joint response under reversed loadings by integrating the material fracture characteristics.     

分布式驱动电动汽车动力学集成控制研究进展及趋势

分布式驱动电动汽车具有四轮可独立控制和响应速度快等突出优势，对增强车辆操纵稳定性、安全性和经济性具有重要的意义。但车辆是一个非线性、强耦合的系统，需研究解决各个控制器相互耦合、过驱动系统复杂性和不确定性等核心问题，这依赖于多维 （纵向、横向和垂向） 集成控制模式和容错控制。对现有研究进行分类和总结，从传统单一维度控制到多维集成控制，综述分布式驱动电动汽车的关键技术和发展现状，重点归纳了汽车动力学集成控制的多层结构及其应用，特别是集成了纵向-横向-垂向动力学的综合控制。最后对分布式驱动电动汽车动力学控制系统所面临的挑战提出了一些建议。