基于传感器的汽车主动安全设计

从汽车主动安全方面进行研究,通过对车辆道路行驶时关键要素的危险状态识别,实现完善汽车主动安全性能.本设计采取自动控制方法,通过研究汽车防碰撞检测和预防以及偏离车道报警,为汽车安全系统提供信息支持,实现车辆主动避免碰撞危险,减少或避免交通事故发生,大大提高汽车行驶主动安全性.所设计汽车主动安全防撞系统主要包括激光防撞测距、激光车道检测、报警警示系统等.     

A compact printed multistubs loaded resonator rectangular monopole antenna design for multiband wireless systems

In the present article, a compact triple‐band multistubs loaded resonator printed monopole antenna is proposed. The antenna consists of a quarter wavelength two asymmetrical inverted L‐shaped stubs to excite two resonant modes for 3.5/5.5 GHz bands and one integrated horizontally T‐shaped stub with inverted long L‐shaped stub to excite resonant mode for 2.5 GHz band. By loading these stub resonators along y‐axis with distinct gaps, the antenna resonates at three frequencies 2.57/3.52/5.51 GHz covering the desired bands while keeping compact size of 24 × 30 mm² (0.2 × 0.25 ). The proposed antenna is fabricated on Rogers RT/duroid 5880 substrate with thickness 0.79 mm and its performance experimentally verified. The measured results reveal that the antenna has the impedance bandwidths of about 210 MHz (2.50‐2.71 GHz), 260 MHz (3.37‐3.63 GHz), and 650 MHz (5.20‐5.85 GHz), for 2.5/3.5/5.5 GHz WiMAX and 5.2/5.8 GHz WLAN band systems. The antenna provides omnidirectional radiation patterns and flat antenna gains over the three operating bands. In addition, the design approach and effects of multistubs resonator lengths on the operating bands are also examined and discussed in detail.     

一种面向汽车电子的配置界面动态生成方法

汽车电子的开发需要根据特定硬件平台资源情况对基础软件功能进行裁剪,而汽车电子的基础软件模块具有配置需求量大、复杂度高等特点。因此,设计一种具有高可配置性、通用的配置工具原型,具有非常重要的应用推广价值。针对汽车电子基础软件的实际需求,提出一种动态生成配置界面的方法。该方法分离配置参数与配置界面,从而极大提高配置工具的可扩展和可维护性。实验结果显示该方法是可行且有效的。     

一种快速有效的印刷体文字识别算法

为了利用低成本的硬件来实现对印刷体文字的快速识别,提出了一种基于多级分类的印刷体文字快速识别算法,该算法从预处理、特征提取,到模式匹配各个阶段,都对传统方法作了合理的改进.该算法首先是采用36×36,而不是传统的48×48点阵进行归一化,从而有效地减少了计算量和字典容量;其次是采用改进的粗外围特征,并进行二重分割,以提高特征的稳定性;最后在各级分类中采用了不同的判别准则,包括绝对值距离、欧氏距离及相似度准则,以适应于时间、准确性的不同要求.同时用该算法对一级汉字7000个样本进行了实验,其结果表明,实际正确识别率(正识率)达95%,前5位累积正识率可达98%,从而为“电子阅读笔”的开发与研制打下了坚实的理论基础.     

电子设备冷却中热电制冷的设计与应用

大适当的应用条件下,热电制冷是一种有效的电子设备冷却方法,经济性是热电制冷器设计与使用的核心问题,本文分析了制冷量对热电制冷设计和控制的影响,给出了一种提高制冷器运行经济性的控制方法。     

浅谈EDA软件在数电教学中的应用

《数字电子技术》是一门很重要的专业基础课,将EDA软件应用到数字电路的教学与实验中,对于数字电路的理论教学、实验教学、课程设计等环节都有显著的帮助,利于学生们更好的掌握这门课程,取得了很好的教学和实验效果。     

Coatings of indium tin oxide nanoparticles on various flexible polymer substrates: Influence of surface topography and oscillatory bending on electrical properties

Abstract— Coatings of indium tin oxide (ITO) nanoparticles on different flexible polymer substrates were investigated with respect to the achievable sheet resistance and their electrical behavior under oscillatory bending. As substrate materials, polyethyleneterephthalate (PET), polyethylenenaphthalate (PEN), polyetheretherketone (PEEK), and polyimide (PI) were chosen, the surface resistances on the different polymer substrates were compared as a function of annealing temperature and surface topography. The surface topography, which has a strong influence on the surface resistance, was characterized by means of a white‐light confocal (WL‐CF) microscope. On the PET substrate, which exhibits the smoothest surface, the coating of ITO nanoparticles shows the lowest sheet resistance of 2 kΩ/□ for a layer thickness of 3 μm and an annealing temperature of 200°C. Furthermore, the electrical behavior of coatings of ITO nanoparticles under oscillatory bending was investigated using a special device. These coatings show a cyclic change of the conductivity which can be explained by an alternating compression and extension of crack flanks under the applied stress. Due to the growing number of cracks with increasing number of cycles, a decrease of the conductivity is observed in the bent state as well as in the balanced state. For a small bending radii, the decrease of the conductivity is stronger due to more cracks caused by the higher tensile stresses in the layer. The electrical behavior of the coatings of the annealed ITO nanoparticles on PET films under oscillatory bending was compared with commercially available sputtered ITO coatings. The annealed coatings of ITO nanoparticles demonstrate better electrical properties under oscillatory bending than coatings of sputtered ITO. The different electrical behavior under oscillatory bending can be related to differences in crack formation.     

未拆/已拆电子元器件的废旧印刷线路板浸铜规律对比研究

以未拆和已拆电子元器件的废旧印刷线路板（Waste Printed Circuit Boards,WPCBs）为研究对象,对比研究了其在硝酸中金属铜的浸出规律。研究结果表明：两者铜的浸出率随粒径的增大、时间的延长和固液比的减小而增大,温度对两者的影响都不大。已拆电子元器件的WPCBs的铜浸出率随H2O2和HNO3用量的增大而增大,而后者在实验讨论的范围内,H2O2和HNO3用量对其浸出率无明显影响。对于1 g样品,当未拆电子元器件的WPCBs粒径为0.25～0.5 mm,固液比为1：1,H2O2和HNO3均为2 mL时,50℃浸出2 h,即可浸出几乎全部的铜;当已拆电子元器件的WPCBs粒径为0.1～0.25 mm,固液比为1：1,H2O2和HNO3用量分别为2 mL和6 mL时,室温浸出2 h,铜浸出率达92.03%。     

以工作过程为导向的汽车发动机电控系统与维修课程教学改革

汽车发动机电控系统与维修是汽电专业的核心课程,如果课程内容脱离实际,教学方法重理论轻实践,就很难达到培养目标。文章通过对汽电专业毕业生从事的职业岗位群进行分析,根据岗位所要求的职业能力和职业素养,分解工作任务,设计教学内容,改革教学方法,完成教学评价。     

关于电力电子技术教学中MAtlAb/Simulink的应用研究

介绍MAtlAb/Simulink仿真软件的功能和仿真过程.以三相桥式全控整流电路为例,进行建模和仿真分析,并用于教学中.