Microstructure and tensile properties of squeeze cast magnesium alloy AM50

High-pressure die cast magnesium alloy AM50 is currently used extensively in large and complex shaped thin-wall automotive components. For further expansion of the alloy usage in automobiles, novelmanufacturing processes need to be developed. In this study, squeeze casting of AM50 alloy with a relatively thick cross section was carried out using a hydraulic press with an applied pressure of 70 MPa. Microstructure and mechanical properties of the squeeze cast AM50 with a cross-section thickness of 10 mm were characterized in comparison with the die cast counterpart. The squeeze cast AM50 alloy exhibits virtually no porosity in the microstructure as evaluated by both optical microscopy and the density measurement technique. The results of tensile testing indicate the improved tensile properties, specifically ultimate tensile strength and elongation, for the squeeze cast samples over the conventional high-pressure die cast parts. The analysis of tensile behavior show that the strain-hardening rate during the plastic deformation of the squeeze cast specimens is constantly higher than that of the die cast specimens. The scanning electron microscopy fractography evidently reveals the ductile fracture features of the squeeze cast alloy AM50.     

基于知识的汽车覆盖件模具标准化数控编程

针对汽车覆盖件模具传统数控编程的缺陷，利用UG软件提供的自动化编程工具，提出了一套基于知识的汽车覆盖件模具标准化数控编程方案，提高了编程效率．而且保证了数控程序的可靠性，并举出了流程模板开发的实例。     

稀土在汽车尾气净化催化剂中的应用现状

详细叙述了用稀土部分替代汽车尾气净化催化剂中铂、铑等贵金属的研究和应用情况。主要包括：①稀土在汽车尾气净化催化剂中应用优势；②稀土催化剂净化汽车尾气中几种主要有害气体的作用机理；③我国从事尾气净化稀土催化剂研究、开发的主要单位和他们各自的研究重点及取得的成果；④稀土三元催化剂的组成、特点及富氧条件下分解NO2的作用机理；⑤纳米稀土催化剂的开发与展望，指出：当纳米稀土催化剂研制成功，可望实现不使用贵金属达到与贵金属催化剂同样的净化效果；⑥稀土催化剂的应用前景。预料，在我国随着汽车保有量的迅速增加，尾气净化催化剂将成为稀土消费的主要领域之一。     

一种高精度车载坡度检测仪的研制

针对现有车载坡度检测技术缺陷,提出了一种高精度车载道路坡度检测仪的设计及实现方案。该检测仪由主控节点和多个检测节点组成,检测节点通过三轴加速度传感器检测与地面倾角,并将其发送给主控节点;主控节点收集各检测节点数据,对其进行数据融合得到坡度的最优估计值。通过仿真和实验验证了方案的可行性,设计成果可广泛应用于车载导航系统中。     

Observer-based predictive controller design with network-enhanced time-delay compensation

State feedback control is very attractive due to the precise computation of the gain matrix, but the implementation of a state feedback controller is possible only when all state variables are directly measurable. This condition is almost impossible to accomplish due to the excess number of required sensors or unavailability of states for measurement in most of the practical situations. Hence, the need for an estimator or observer is obvious to estimate all the state variables by observing the input and the output of the controlled system. As such, the goal of this paper is to provide a control design methodology based on a Luenberger observer design that can assure the closed-loop performances of a vehicle drivetrain with backlash, while compensating the network-enhanced time-varying delays. This goal is achieved in a sequential manner: firstly, a piecewise linear model of two inertias drivetrain, which takes into consideration the backlash nonlinearity and the network-enhanced time-varying delay effects is derived; then, a Luenberger observer which estimates the state variables is synthesized and the robust full state-feedback predictive controller based on flexible control Lyapunov functions is designed to explicitly take into account the bounds of the disturbances caused by time-varying delays and to guarantee also the input-to-state stability of the system in a non-conservative way. The full state-feedback predictive control strategy based on the Luenberger observer design was experimentally tested on a vehicle drivetrain emulator controlled through controller area network, with the aim of minimizing the backlash effects while compensating the network-enhanced delays.     

Retrofitting of pedestrian overpass by Truss-Z modular systems using graph-theory approach

Installing pedestrian ramps is a common improvement towards a barrier-free environment. This paper introduces a graph-theoretical method of retrofitting of a single-branch Truss-Z (TZ) ramp in a constrained environment. The results produced by this exhaustive search method are usually ideal and better than those produced previously with meta-heuristic methods.A large case study of linking two sections of the Hongo Campus of Tokyo University using an overpass in an extremely constrained environment is presented. TZ modules with 1:12 (8.3%) slope are used, which is allowable in most countries for ramps for self-powered wheelchairs.The results presented here are highly satisfactory both in terms of structural optimization and aesthetics.Visualizations of the TZ ramp system, composed of 124 units, are presented.     

Output feedback of Markov jump linear systems with no mode observation: An automotive throttle application

The note presents an output feedback control strategy for Markov jump linear systems with no mode observation. Based on minimizing a finite‐time quadratic cost, we derive an algorithm that generates output feedback gains that satisfy a necessary optimality condition. These gains can be computed off‐line relying only on the initial condition of the system. This result expands a previous one from the literature that considered state‐feedback only. To illustrate the usefulness of the approach, real‐time laboratory experiments were performed to control an automotive electronic throttle valve subject to Markov‐driven voltage fluctuations. Copyright © 2015 John Wiley & Sons, Ltd.     

基于CAN总线的汽车开关电器盒设计

以Microchip公司的PIcl8F45K80芯片为核心,给出了具有低成本、高扩展性的实用型多功能汽车开关电器盒的设计方法。该开关电器盒除了具有对汽车启动过程和行驶状态参数实时监测的功能外,与其他同类产品相比,还更加注重产品的实用性和扩展性,同时具备与汽车其他设备进行通信的特有功能。     

单张图片树木L-system的智能提取算法

介绍了一种新颖的从单张树木图片中提取树木的L-system规则的算法,并将其应用于三维树木建模。用户首先在图片上勾画出树木的主要可见枝干和树冠轮廓,通过图像处理的方法识别出树木的可见枝干的二维骨架;然后依据树木枝干的分布规律对骨架进行三维重建,并抽取其L-system生长规则和几何参数。所得L-system规则在树冠轮廓的约束下,经过迭代生长可以重建树木的分支结构。实验证明,相比以往的规则提取方法,该方法在保持模型质量的前提下,成本更低,方法更加简便。     

汽车电子控制系统软件建模分析与研究

分析和比较了不同软件建模方法的适用条件和使用利弊,并针对现有建模软件的缺点及汽车电子控制系统所具有的目的性、相关性、层次性、随机性等特点,采用面向对象的软件建模方法建立汽车电子控制系统模型,完整和直接的映射了汽车电子控制系统的问题域,较好的模拟了现实世界的属性和操作。最后以汽车ABS（Anti-lock Braking System,防抱制动系统）为例说明了此方法在建模效果上的有效性和合理性。