Bending-stretching analysis of thick functionally graded micro-plates using higher-order shear and normal deformable plate theory

In the present article, higher-order shear and normal deformable plate theory together with modified couple stress theory are developed to study the bending analysis of thick functionally graded rectangular micro-plates. One material length scale parameter is used for capturing the size effects. Utilizing the variational approach and also a principle of virtual displacement, a new form of equilibrium equations and the corresponding boundary conditions are derived. It is assumed that material properties vary through the thickness according to the power law function. Finally, an analytical solution for the bending problem of a simply supported FG rectangular micro-plate is presented.     

汽车造型的工程属性与情感属性的映射关系研究

目的研究汽车造型中的工程属性与情感属性存在的映射和对应关系,以及对于设计评价的影响。方法通过文献研究和实验分析,揭示了汽车造型中的工程属性与情感属性的映射和转换关系。结论造型中的工程属性能与情感属性存在内在的映射与转化关系,可以提高设计方案在跨学科研发团队中的沟通效率,提高设计创意的"编码"和"解码"。对于汽车创意和评价具有重要的参考价值,可以提高设计方案在跨学科研发团队中的多向沟通效率,提高设计方案的接受度和可行性。     

一种耐振动远距离输送的常温乳化基质的研制

介绍了一种耐振动、适宜远距离运输、现场装药车装药的乳化基质的研制。经检测,该乳化基质抗振动性好,在振动频率为1 Hz时,振动20 h后仍不破乳、不老化,敏化后爆速稳定;黏度适中,常温黏度为40 000 m Pa·s,不仅有利于现场装药车泵送,且耐储存,储存期达到30 d;敏化后爆速比普通混装乳化基质高,达到5 000 m/s以上;安全性好,摩擦感度和撞击感度均为0。可以满足长距离运输现场装药车装填的需要,适用于各类露天矿山远程配送装填使用。     

Rolling texture and its effect on tensile property of a near-α titanium alloy Ti60 plate

Rolling texture and its effect on tensile properties of Ti60 alloy plates were investigated in the present study. The plates wereβ-rolled at 1070℃ and(α+β)-rolled at 980℃, using uni-directionally rolling(UDR) and cross-directionally rolling(CDR) processes, respectively.β-rolled plates exhibited weak textures, which were attributed to the dispersive orientations of secondary α during the β→α phase transformation. Strong deformation textures formed in(α+β)-rolled plates as a result of slipping mechanisms: the strong T-type texture in UDR plate was related to {10 1 0}[11 2 0] slipping, while the B-type texture in CDR plate was relevant with {0001}[11 2 0] slip. Strong T-type textures led to anisotropic tensile properties. B-type textures would decrease such an anisotropy. The(α+β)-CDR process was found to be a candidate process for reducing anisotropy of Ti60 alloy plates.     

基于FFT-OMP-DAMAS波束形成方法的汽车前围板隔声薄弱部位识别

为实现汽车前围板隔声薄弱部位的准确识别,文章提出了基于快速傅里叶变换(Fast Fourier Transform,FFT)和正交匹配追踪(Orthogonal Matching Pursuit,OMP)的反卷积(Deconvolution Approach for the Mapping of Acoustic Sourc‐es,DAMAS)波束形成方法(FFT-OMP-DAMAS)。该方法基于声源稀疏分布假设,利用正交匹配追踪思想求解反卷积问题,并进一步结合傅里叶变换和点扩散函数空间转移不变假设降低计算维度。在混响室-消声室内,分别利用延迟求和方法,DAMAS方法和FFT-OMP-DAMAS方法进行了某汽车前围板隔声薄弱部位识别试验,结果表明：FFTOMP-DAMAS方法能够有效抑制旁瓣和伪源,有效缩减主瓣宽度,从而准确识别汽车前围板隔声薄弱部位,且相较于传统的DAMAS方法,文中提出的FFT-OMP-DAMAS方法能获得更清晰的成像结果,计算效率有了明显提高。     

基于行扫描的炮弹引信铆点特征提取

在炮弹引信铆点机器视觉识别中,有效消除图像中各种干扰、正确提取铆点特征是关键,解决好铆点特征的准确提取问题,是炮弹引信安全破除铆点的前提条件;根据铆点的结构特点,分析了产生各种干扰的原因及特点,在高斯滤波,阀值分割、形态学运算等基本运算的基础上,提出了一种基于行扫描的铆点特征提取方法;测试结果表明,提出的方法可行,铆点正确识别率达到90%以上,具有高效性和很好的鲁棒性的铆点特征提取,使得炮弹铆点的准确破除成为可能.     

大视觉智能巡线车控制系统开发

针对常规的智能车传感器固定,视觉范围小,影响智能车的运行速度和准确性问题,提出了基于双舵机的大视觉智能巡线车控制系统。采用激光传感器、将路径识别传感器安装在车架上随动舵机的轮盘上,MCU通过控制随动摆头舵机来带动传感器的运动,使智能车的路径识别角度范围增大。经试验证明,此控制系统紧密结合双舵机的特点,充分发挥装在车架上的随动舵机带动路径识别传感器的优势,增大了智能车巡线过程中能识别到的路径范围,使智能车模实现高速稳定行驶。在不"丢线"的情况下,速度得到较大的提升,能适应各种赛道。     

基于SD卡的智能车调试系统设计

介绍了一种基于SD卡的摄像头智能车调试系统。摄像头智能车数据量大。利用SD卡将小车在实际跑的过程中的图像信息、状态信息和控制信息储存下来供离线分析,捕捉到了很多错误,为小车在跑道上平稳快速的运行提供了保障。     

基于红外反射式传感器的循迹车系统设计

采用红外反射式传感器设计了一种循迹车系统。硬件方面,介绍了红外循迹电路、电机驱动电路和测温模块的设计方法;软件方面,给出了循迹模块算法和目标物识别算法。经实验验证,循迹车能在黑色引导线上稳定可靠地运行,并在偏离导线时自动纠偏。     

Robust MIMO disturbance observer analysis and design with application to active car steering

A multi‐input–multi‐output extension of the well‐known two control degrees‐of‐freedom disturbance observer architecture that decouples the problem into single‐input–single‐output disturbance observer loops is presented in this paper. Robust design based on mapping D‐stability and the frequency domain specifications of weighted sensitivity minimization and phase margin bound to a chosen controller parameter space is presented as a part of the proposed design approach. The effect of the choice of disturbance observer Q filter on performance is explained with a numerical example. This is followed by the use of structured singular values in the robustness analysis of disturbance observer controlled systems subject to structured, real parametric and mixed uncertainty in the plant. A design and simulation study based on a four wheel active car steering control example is used to illustrate the methods presented in the paper. Copyright © 2009 John Wiley & Sons, Ltd.