A new offline optimization approach for designing a fuel cell hybrid bus

In this study a hydrogen powered fuel cell hybrid bus is optimized in terms of the powertrain components and in terms of the energy management strategy. Firstly the vehicle is optimized aiming to minimize the cost of its powertrain components, in an official driving cycle. The optimization variables in powertrain component design are different models and sizes of fuel cells, of electric motors and controllers, and batteries. After the component design, an energy management strategy (EMS) optimization is performed in the official driving cycle and in two real measured driving cycles, aiming to minimize the fuel consumption. The EMS optimization is based on the control of the battery’s state-of-charge. The real driving cycles are representative of bus driving in urban routes within Lisbon and Oporto Portuguese cities. A real-coded genetic algorithm is developed to perform the optimization, and linked with the vehicle simulation software ADVISOR. The trade-off between cost increase and fuel consumption reduction is discussed in the lifetime of the designed bus and compared to a conventional diesel bus. Although the cost of the optimized hybrid powertrain (62,230 €) achieves 9 times the cost of a conventional diesel bus, the improved efficiency of such powertrain achieved 36% and 34% of lower energy consumption for the real driving cycles, OportoDC and LisbonDC, which can originate savings of around 0.43 €/km and 0.37 €/km respectively. The optimization methodology presented in this work, aside being an offline method, demonstrated great improvements in performance and energy consumption in real driving cycles, and can be a great advantage in the design of a hybrid vehicle.     

机动车辆危险因素分析及事故防范对策

随着经济的快速发展,机动车辆迅速增加,交通条件与交通流量之间的矛盾日益突出,机动车辆所引起的交通事故逐年增加,给人民生命财产造成巨大损失的同时也对社会带来负面影响。本文深入分析了机动车辆的危险因素及发生交通事故的主要原因,并提出相应的预防和控制措施。讨论了驾驶员心理素质的重要性和酒驾的危害性,提出驾照考试引入心理学测试、对酒驾等严重违章行为立法严惩等建议;提出对现有车道的改进方案以及所有机动车辆必须安装测距传感器的设想,并针对交通信号灯提出了改进措施。     

Electric vehicles: How much range is required for a day’s driving?

One full year of high-resolution driving data from 484 instrumented gasoline vehicles in the US is used to analyze daily driving patterns, and from those infer the range requirements of electric vehicles (EVs). We conservatively assume that EV drivers would not change their current gasoline-fueled driving patterns and that they would charge only once daily, typically at home overnight. Next, the market is segmented into those drivers for whom a limited-range vehicle would meet every day’s range need, and those who could meet their daily range need only if they make adaptations on some days. Adaptations, for example, could mean they have to either recharge during the day, borrow a liquid-fueled vehicle, or save some errands for the subsequent day. From this analysis, with the stated assumptions, we infer the potential market share for limited-range vehicles. For example, we find that 9% of the vehicles in the sample never exceeded 100 miles in one day, and 21% never exceeded 150 miles in one day. These drivers presumably could substitute a limited-range vehicle, like electric vehicles now on the market, for their current gasoline vehicle without any adaptation in their driving at all. For drivers who are willing to make adaptations on 2 days a year, the same 100 mile range EV would meet the needs of 17% of drivers, and if they are willing to adapt every other month (six times a year), it would work for 32% of drivers. Thus, it appears that even modest electric vehicles with today’s limited battery range, if marketed correctly to segments with appropriate driving behavior, comprise a large enough market for substantial vehicle sales. An additional analysis examines driving versus parking by time of day. On the average weekday at 5 pm, only 15% of the vehicles in the sample are on the road; at no time during the year are fewer than 75% of vehicles parked. Also, because the return trip home is widely spread in time, even if all cars plug in and begin charging immediately when they arrive home and park, the increased demand on the electric system is less problematic than prior analyses have suggested.     

日本东洋电机齿轮驱动装置制造技术

介绍了日本东洋电机齿轮驱动装置的加工、组装、试验和检测工艺流程。     

机车电机主动齿轮轴轴承布置分析

研究了现有的3种机车电机主动齿轮轴轴承布置方式.从轴承寿命和齿轮啮合2个方面对3种布置方式进行比较.使用有限元软件ANSYS计算分析了3种结构的齿轮轴变形和齿轮啮合时的应力.计算结果表明:主动齿轮轴两端支撑结构对轴承受力和齿轮啮合最有利.与传统主动齿轮悬臂结构相比两端支撑结构的轴承寿命提高了17.51倍、轮齿接触应力降低45.7%、轮齿齿根弯曲应力减小62.8%.     

机车应急驾驶模式的原理及应用

文章引入交流传动电力机车所采用的一种全新的应急驾驶模式,介绍其工作原理及应用情况。应急驾驶模式的采用解决了机车运行中经常出现的几种与级位设定有关的故障,提高了机车运行的可靠性。     

A human-in-the-loop wireless warning message notification model and its application in connected vehicle systems

Objective: Vehicle-to-vehicle (V2V) communication has become one of the most active fields of research recently. The implementation of the wireless connected vehicles has widely extended the transmission range of warning messages to inform drivers of hazards ahead. The present study addressed the human component with mathematical modeling of the human reaction time to warning messages in the connected vehicle systems (CVSs) with different confidence intervals (CIs). Methods: In the present study, human performance in warning responses is modeled by extending an existing mathematical model of human performance with the complexity level of tasks. The modeling of human performance with different levels of uncertainty is integrated to propose the warning message notification model in the CVS settings. The warning message notification models were proposed to model the CVSs parameters including maximum available message notification delay, the maximum available machine processing time, the minimum acceptable message notification range, and the designed message display delay. Results: The optimal designs of CVSs parameters were presented in general and for specific conditions by applying the modeling of human performance with different CIs (i.e., 95% and 99% CI) and the warning message notification model with human in the loop. A software interface with the message notification model implemented was presented to discuss the practical benefits of the current work in the design of CVSs.     

关于L3自动驾驶的人机交互设计研究

随着雷达、摄像头、处理平台的软硬件提升,加上高精地图的辅助,全球越来越多的汽车公司都推出了自动驾驶车辆,覆盖Level 2~Level 3的自动驾驶场景(SAE J3016),但这些场景都需要在必要的时候由驾驶员接管车辆,因此自动驾驶汽车对人机交互设计提出了新的挑战,比如合理的接管流程,驾驶操作的监测,权责划分的提示。     

基于车轴图谱的城市道路汽车运行轨迹特性分析

为探究城市道路行车轨迹与路侧之间的横向距离对车辆运行的影响,提高驾驶员行车安全,在某市滨海路进行汽车运行轨迹样本采集试验,使用AxleLight RLU11系列路侧交通数据采集系统分车道采集试验路段汽车运行轨迹样本,利用SPSS Statistics对试验路段不同车道车辆运行轨迹样本进行数据处理,绘制不同行车道运行车辆横向距离的累积频率曲线,计算得到汽车运行轨迹与路侧的横向距离D85,通过绘制行驶车辆距路侧的横向距离直方图,得到不同车道的车辆分布规律。结果显示,驾驶员大多数偏向选择在内侧车道运行。根据试验路段内外2条车道车辆横向距离和运行轨迹特性,可为城市道路交通安全设施的设置提供理论依据,以期提高城市道路交通运行安全。