高亮度LED在现代汽车照明中的应用

LED相对于传统的白炽光照明具有许多优势,高亮度LED在汽车照明的应用前景广阔,但仍需克服许多困难。采用特定的方法对电流、噪声、温度和亮度进行控制,可以解决高亮度LED的关键技术问题。随着高亮度LED在汽车照明领域的关注度不断提高,其应用市场也正在逐步扩大。使用高亮度LED照明必将成为未来汽车的主要特征之一。     

汽车尾气温差发电效率的影响因素

汽车尾气温度高,带走的热量约占发动机总能量的40%,温差发电技术能直接将废热能量转化为电能回收利用。文章介绍了汽车排气废热温差发电系统的输入输出特性,探讨了影响系统发电效率的相关因素,并提出改进措施。经过一系列试验验证及理论研究表明,系统效率受废热通道内部结构、热电模块拓扑结构以及热电模块自身性能的影响。提出的改进方案提高了温差发电系统的热效率。     

大功率LED汽车前照灯散热设计

基于目前的半导体制造技术,LED输入功率中只有大约15%的能量转化为光能,其它的则转化热能,如果LED散热问题解决不好,输出光功率减小,加速芯片蜕化,寿命缩短,不能突显灯具的优势。文章在某轿车现有前照灯组合结构的基础上,制作了LED汽车前照灯样灯。介绍了热管散热器的导热和散热方式,仿真和测试结果表明散热效果较好,指出热管散热器存在一定的局限性,散热方式应该向智能散热方向发展。     

Real time detection of driver attention: Emerging solutions based on robust iconic classifiers and dictionary of poses

Real time monitoring of driver attention by computer vision techniques is a key issue in the development of advanced driver assistance systems. While past work mostly focused on structured feature-based approaches, characterized by high computational requirements, emerging technologies based on iconic classifiers recently proved to be good candidates for the implementation of accurate and real-time solutions, characterized by simplicity and automatic fast training stages.In this work the combined use of binary classifiers and iconic data reduction, based on Sanger neural networks, is proposed, detailing critical aspects related to the application of this approach to the specific problem of driving assistance. In particular it is investigated the possibility of a simplified learning stage, based on a small dictionary of poses, that makes the system almost independent from the actual user.On-board experiments demonstrate the effectiveness of the approach, even in case of noise and adverse light conditions. Moreover the system proved unexpected robustness to various categories of users, including people with beard and eyeglasses. Temporal integration of classification results, together with a partial distinction among visual distraction and fatigue effects, make the proposed technology an excellent candidate for the exploration of adaptive and user-centered applications in the automotive field.     

Ergonomic and biomechnical analysis of automotive general assembly using XML and digital human models

Automotive general assembly requires many manual assembly operations to be carried out by human workers. Ergonomic analysis is an important part of the design and evaluation of products, jobs, tools, machines and environments for safe, comfortable and effective human functioning. Most recent researches have involved the evaluation of working conditions to prevent work-related musculoskeletal disorders. The majority of previous research on automotive companies has mainly considered the results of ergonomic analyses such as RULA (Rapid Upper Limb Assessment), REBA (Rapid Entire Body Assessment) and OWAS (Ovako Working Posture Analysis System). Analysis of static posture including reachability, clearances for arm, hand and tool has also been used to evaluate working conditions. However, in addition to static posture analysis, a biomechanical analysis in dynamic conditions should also be conducted. There are no integrated frameworks or standard schema for ergonomic analysis using digital human models in digital environments. The purpose of this paper is to propose a new framework for the evaluation of working conditions by ergonomic and biomechanical analysis using digital models based on XML standard schema, including: products, processes, manufacturing resources and human workers. This paper presents the analysis results using the proposed framework for automotive general assembly operations. We propose a new framework for the evaluation of the assembly operations and their environments. Then we apply a digital human model to the dynamic simulation of general automotive assembly operations based on standard schemas in XML and PPRH (Product, Process, Resource and Human). Using PPRH information based on a standard XML schema to analyze the ergonomic and biomechanical results, the engineer can visualize, analyze and improve assembly operations and working environments in automotive general assembly shops using digital models.     

Thermal design of automobile exhaust based thermoelectric generators: Objectives and challenges

The potential for thermoelectric power generation (via waste heat recovery onboard automobiles) to displace alternators and/or provide additional charging to a vehicle battery pack has increased with recent advances in thermoelectric material processing. In gasoline fueled vehicles (GFVs), about 40% of fuel energy is wasted in exhaust heat, while a smaller amount of energy (30%) is ejected through the engine coolant. Therefore, exhaust-based thermoelectric generators (ETEG) have been a focus for GFV applications since the late 1980s. The conversion efficiency of modern thermoelectric materials has increased more than three-fold in the last two decades; however, disputes as to the thermal design of ETEG systems has kept their overall efficiency at limited and insufficient values. There are many challenges in the thermal design of ETEG systems, such as increasing the efficiency of the heat exchangers (hot box and cold plate), maintaining a sufficient temperature difference across the thermoelectric modules during different operating conditions, and reducing thermal losses through the system as a whole. This paper focuses on a review of the main aspects of thermal design of ETEG systems through various investigations performed over the past twenty years. This paper is organized as follows: first, the construction of a typical ETEG is described. The heat balance and efficiency of ETEG are then discussed. Then, the third section of this paper emphasizes the main objectives and challenges for designing efficient ETEG systems. Finally, a review of ETEG research activities over the last twenty years is presented to focus on methods used by the research community to address such challenges.     

汽车实用性质量评价系统（APQAS）的设计与应用

APQAS（Automobile Practical Quality Assessment System)对汽车售后服务中搜索的实用性质量信息，按汽车故障学原理分类编码建立大样本的实用性质量信息数据库，并根据《汽车产品质量检验评定》标准，运用数据统计分析方法，全面分析评价汽车产品的总体质量，设计质量和生产质量，由于APQAS的质量评价具有明显的滞后性，其不能代产品质量试验性评价，两的有机结合可以显提高产品质量评价的水平和效能。     

汽车运行材料的应用现状及发展趋势

综述了汽车用燃料(汽油、柴油、代用燃料)、润滑剂(发动机润滑油、齿轮油、自动变速器油、润滑脂)、特种液(制动液、冷却液、空调制冷剂)、燃料添加剂及润滑剂添加剂等运行材料在国内外的应用现状及发展趋势。该研究可为汽车运行材料的新产品研发提供参考。     

基于ABAQUS汽车发动机缸体缸盖温度场分析

为了在发动机开发初期了解发动机各结构的温度分布情况,文章采用有限元的方法对某发动机进行温度场分析。先运用Fire软件计算近壁面的温度场及流场,然后将温度以及换热系数映射到结构网格的单元上,再利用ABAQUS进行结构的温度场分析。通过对结果的分析发现,气缸盖的鼻梁区部分温度较高,但所有部件的温度均未超过材料的极限值,整个发动机的温度场分布较合理。     

汽车轻量化技术的应用

应用汽车轻量化技术可实现减轻汽车质量,解决节能与环保问题。文章通过轻量化对促进汽车工业健康发展重要性的论述,阐明轻量化技术在汽车结构优化设计、轻量化材料开发应用及新工艺上实现的方法和主要作用,以及产品全生命周期评价列为轻量化技术之一的考虑,揭示汽车轻量化技术的主要应用方向和应用现状,强调轻量化技术在汽车轻量化中的重要作用与前景。