-汽车倒泊防撞报警器的设计.doc

毕业设计（论文）题目： 汽车倒泊防撞报警器的设计 毕业设计（论文）原创性声明和使用授权说明原创性声明本人郑重承诺：所呈交的毕业设计（论文），是我个人在指导教师的指导下进行的研究工作及取得的成果。尽我所知，除文中特别加以标注和致谢的地方外，不包含其他人或组织已经发表或公布过的研究成果，也不包含我为获得 及其它教育机构的学位或学历而使用过的材料。对本研究提供过帮助和做出过贡献的个人或集体，均已在文中作了明确的说明并表示了谢意。作 者 签 名： 日 期： 指导教师签名： 日期： 使用授权说明本人完全了解 大学关于收集、保存、使用毕业设计（论文）的规定，即：按照学校要求提交毕业设计（论文）的印刷本和电子版本；学校有权保存毕业设计（论文）的印刷本和电子版，并提供目录检索与阅览服务；学校可以采用影印、缩印、数字化或其它复制手段保存论文；在不以赢利为目的前提下，学校可以公布论文的部分或全部内容。作者签名： 日 期： 学位论文原创性声明本人郑重声明：所呈交的论文是本人在导师的指导下独立进行研究所取得的研究成果。除了文中特别加以标注引用的内容外，本论文不包含任何其他个人或集体已经发表或撰写的成果作品。对本文的研究做出重要贡献的个人和集体，均已在文中以明确方式标明。本人完全意识到本声明的法律后果由本人承担。作者签名： 日期： 年 月 日学位论文版权使用授权书本学位论文作者完全了解学校有关保留、使用学位论文的规定，同意学校保留并向国家有关部门或机构送交论文的复印件和电子版，允许论文被查阅和借阅。本人授权 大学可以将本学位论文的全部或部分内容编入有关数据库进行检索，可以采用影印、缩印或扫描等复制手段保存和汇编本学位论文。涉密论文按学校规定处理。作者签名：日期： 年 月 日导师签名： 日期： 年 月 日注 意 事 项1.设计（论文）的内容包括：1）封面（按教务处制定的标准封面格式制作）2）原创性声明3）中文摘要（300字左右）、关键词4）外文摘要、关键词 5）目次页（附件不统一编入）6）论文主体部分：引言（或绪论）、正文、结论7）参考文献8）致谢9）附录（对论文支持必要时）2.论文字数要求：理工类设计（论文）正文字数不少于1万字（不包括图纸、程序清单等），文科类论文正文字数不少于1.2万字。3.附件包括：任务书、开题报告、外文译文、译文原文（复印件）。4.文字、图表要求：1）文字通顺，语言流畅，书写字迹工整，打印字体及大小符合要求，无错别字，不准请他人代写2）工程设计类题目的图纸，要求部分用尺规绘制，部分用计算机绘制，所有图纸应符合国家技术标准规范。图表整洁，布局合理，文字注释必须使用工程字书写，不准用徒手画3）毕业论文须用A4单面打印，论文50页以上的双面打印4）图表应绘制于无格子的页面上5）软件工程类课题应有程序清单，并提供电子文档5.装订顺序1）设计（论文）2）附件：按照任务书、开题报告、外文译文、译文原文（复印件）次序装订3）其它目 录一、毕业设计（论文）开题报告二、毕业设计（论文）外文资料翻译及原文三、学生“毕业论文（论文）计划、进度、检查及落实表”四、实习鉴定表xx大学xx学院毕业设计（论文）开题报告题目： 汽车倒泊防撞报警器的设计 系 专业学 号： 学生姓名： 指导教师： （职称： ） （职称： ）xxxx年x月xx日 课题来源由于随着科学技术和汽车工业的发展，许许多多的汽车安全装置也得到大力的发展。汽车上面安装防撞警报器能够极大的方便司机的驾驶，保障司机的安全，并且能在紧急情况下能自动刹车防止汽车之间的相撞。随着人们安全意识的提高，在汽车上安装防撞倒泊警报器将必不可少。科学依据（包括课题的科学意义；国内外研究概况、水平和发展趋势；应用前景等）在当今社会，知识的实用性越来越得到重视。如何从海量的知识群中找出有用的知识并付诸实践，这是很值得摸索的。单片机的应用日益普及，汽车的数量急剧增加，保障汽车驾驶人员的安全也变得越来越重要了。目前在汽车警报器经过20多年的发展 ，已经历了从开始的由单片机的蜂鸣器到由频率控制声音的急促报警到进一步的可视的智能化防撞报警系统。汽车防撞装置主要是通过车与障碍物之间的距离，车速信号的发射与接收由信号控制系统既是利用单片机来控制车速。并发出不同频率的报警信号。当车速与车距距离进入比较危险的状态时，单片机自动控制发出紧急制动信号刹车，以此来达到防撞的目的。由上述可知，汽车与障碍物的距离只有在危险距离状态才有发生碰撞的可能，汽车防撞装置系统的设计任务主要是采集汽车与障碍物的距离和本车车速，并与当时车速下安全警报距离与危险距离之间进行比较，判断汽车与障碍物的距离是否安全。当达到的安全警报距离时能发出声音报警。研究内容在倒车时不断测量汽车尾部与其后面障碍物的距离，并实时显示其与障碍物之间的距离，在不同的距离范围内发出不同的报警信号，并且提高报警系统的稳定性，以提高汽车倒车时的安全性。本文设计了一种超声波汽车倒泊防撞报警器，本报警器具有以下功能：最大测距4.9m，最小测距0.1m，实时显示测得的距离；在不同的时间利用三个不同的超声波传感器进行测距，能够有效的提高报警的稳定性。在不同的危险距离范围内发出不同的频率报警信号，驾驶员还可以根据个人需要调整设置报警距离。利用555来控制蜂鸣器的发声频率，直接运用单片机的I/O口控制报警器的工作。能够大大降低软件的复杂程度。该报警器与其它报警器相比具有功能多、硬件电路简单、工作稳定可靠等优点。拟采取的研究方法、技术路线、实验方案及可行性分析研究方法：理论联系实际。技术路线：理论联系实际。实验方案：对比“基于AT89C51单片机的超声波防撞报警系统”跟“基于AT89C2051单片机的超声波防撞报警系统”，前者性价比更高，所以选择前者。可行性分析：能够理论联系实际解决实际性的问题。此方案可行。研究计划及预期成果初步讨论基于AT89C51单片机来实现汽车倒泊防撞警报器的设计，分析了运用AT89C51和AT89C2051作为主控制器的两种方案。重点介绍了AT89C51来实现的方案。对控制器，超声波发射电路，超声波接收电路，高低频报警电路，LED显示电路等模块，以及运用单片机的I/O口如何具体的控制作了一定的说明。第四部分中，介绍系统的硬件框图、软件流程图、中断子程序流图等，给出了具体的软件实现的方案。利用51 系列单片机设计的测距仪便于操作、读数直观。测距仪工作稳定, 能满足一般近距离测距的要求, 且成本较低、有良好的性价比。特色或创新之处考虑非常周全，不但提供了相应的理论基础知识，一定的电子电路图，还为详细的设计过程截取图片已具备的条件和尚需解决的问题对于AT89C51单片机来实现汽车的倒泊防撞警报器尚取得了一定进展，但是还是有很多的不足之处：（1）应该引入更加完善的显示系统，是司机能更加清楚的了解倒车时的情况。（2）引入先进的语音模块，通过人性化的语音报警信号。（3）在紧急情况，应该自动使汽车紧急刹车，防止汽车与障碍物之间相撞。（4）应该对该警报器进行实际的测量，适当的进行调节，最大限度的减少误差。但是未来利用单片机来实现汽车的倒泊防撞警报器仍然有广阔的前景，随着单片机的功能日渐增强，能够使报警更加人性化指导教师意见 指导教师签名：年 月 日教研室（学科组、研究所）意见 教研室主任签名： 年 月 日系意见 主管领导签名： 年 月 日外文原文Microelectronic EngineeringSouth KoreabSchool of Information and Communication Engineering, College of Engineering, Inha University, Incheon 402-751, South Korea cDepartment of Electrical Engineering, College of Engineering, Choongang University,Seoul 156-756, South Korea.Available online 17 February 2006. AbstractWe report on the fabrication of a polymer-based 2.5Gbps4 channel optical interconnecting micro-module for optical printed circuit board (O-PCB) application. An optical waveguide array is used for optical transmission from vertical surface emitting laser (VCSEL) array to photodiode (PD) array and the built-in 45 waveguide mirrors are used for vertical coupling. The optical waveguide array and the 45 mirrors are fabricated by UV imprint process in one-step. We fabricate microlensed VCSELs by micro-inkjetting method, which reduced radiation angle of VCSEL from 18 to 15 for better light coupling. We use solder ball array and pin array for alignment between O-PCB and the electrical sub-boards with alignment mismatch below 10m in x, y and z axis. The fabricated optical interconnection module transmits data at the rate of 2.5Gbps per channel.Keywords: Optical interconnection; Photonic integrated circuit; Micro-fabrication; UV embossingArticle Outline1. Introduction 2. Fabrication of waveguide array and 45 mirrors 3. Microlensed VCSEL 4. Passive alignment 5. Optical interconnect modules 6. Conclusion Acknowledgements References1. IntroductionIn the progresses of microprocessor and the input-output (IO) devices, the need for higher bandwidth is rapidly growing. High speed interconnects are demanding next generation IO interconnects of highly increased data capacity because todays IO interconnects are suffering bottleneck in bandwidth at the IO interface. Many attempts to increase the IO interconnect bandwidth have emerged 1. These attempts to extend electrical interconnect in more bandwidth manner are hard to solve fundamental problems facing the limitation of electrical properties over gigabits per channel data capacity.Operation of electrical interconnect schemes in gigabit regime will meet bottlenecks related to the properties of electrical interconnects, including material properties, skew, jitter, EMI, and power consumption. To improve the performances of electrical interconnects, many efforts in signal processing techniques such as pre-emphasis, equalization, multilevel signaling, and coding, deterministic jitter are needed to keep the trace of the bandwidth progress 2, 3 and 4.Optical interconnection has a potential as an alternative approach to solve these problems because optical interconnection has many advantages over electrical interconnection such as high frequency, high bandwidth, light, immunity to EMI, low skew, low jitter, no need of ground line, easy for impedance matching.To realize an optical interconnection module for O-PCB application, various photonic devices like light sources, detector arrays, and waveguide arrays are needed. The waveguides are interconnected to light sources and photo-detectors in a multiple array. The 45 waveguide mirrors are used for interconnecting VCSEL arraywaveguide array/waveguide arrayPD array. Once the O-PCB is designed and fabricated it has to be put together with the existing electrical circuits such as driving circuits for micro-lasers and micro-detectors. Hence, we need micro-fabrication techniques for realizing optical interconnection module.We carried out micro-fabrication for optical interconnection module, which include design and fabrication of waveguides, coupling schemes and passive alignment. For this, we focus on the following issues: One is the concurrent fabrication of a waveguide array and 45 mirrors in one-step in order to reduce the number of processing steps for low-cost production and another is a method to improve coupling efficiency between VCSEL arraywaveguide array/waveguide arrayPD array including the passive alignment method between the different parts of the optical interconnection module. This paper demonstrates a micro-fabrication of optical interconnection module to be used for the realization of optical printed circuit board (O-PCB) 7 and 8.2. Fabrication of waveguide array and 45 mirrorsTo use polymers as materials of the waveguide, embossing technique is used because of its relatively easy fabrication process. We fabricated polymer waveguides by UV embossing, which also involves fabrication of mold and replica. UV curable polymers are used as materials of waveguides and silicon mold is used to form waveguide patterns. For vertical coupling between VCSEL array and waveguide array and between the waveguide array and the PD array, we have to utilize mirror face at each end of the waveguide. To achieve this process, waveguide mold equipped with 45 faces at each end of the mold is needed to form the vertical coupling structure in a single fabrication step. We made a 12 channel silicon waveguides mold, which has 45 mirror face at the ends of each waveguide. The dimension of the waveguide is 50m width and 50m height and the waveguide layout pitch is 250m and the length is 7cm. With this mold, we performed UV embossing to make embedded type waveguides.To fabricate a 12 channel silicon waveguides mold, we etched silicon substrate with KOH-saturated isopropanol solutions in two steps: First is to make a vertical coupling path for the waveguides and the other is to make 45 slope for the fabrication of mirror faces. First, a metallic mask is patterned on the silicon substrate and the silicon is vertically etched with KOH to form a waveguide pattern. In the next step to form 45 slope, a thin film of SiO2 is grown on patterned waveguide. And photoresist is patterned at the end of the each waveguide structure and the ends of the waveguides are etched with KOH-saturated isopropanol solution to form 45 slope. After the SiO2 is stripped, the process of fabricating silicon mold equipped with 45 mirror is completed.We fabricated 12 channel embedded waveguide array by UV embossing using the prefabricated silicon mold. Waveguide fabrication process is shown in Fig. 1. UV curable polymer, which is used as cladding layer with index as 1.45 at 850nm wavelength, is dropped in the hollow cavity of a transparent substrate such as PDMS template. After silicon mold is pressed on template the UV light is irradiated. Silicon mold is detached and metallic film is coated on the 45 slope at the end of the waveguide to enhance coupling efficiency. And then the core polymer is dropped and a flat substrate is covered and pressed onto the core material which is also UV curable polymer with refractive index of 1.47 at 850nm wavelength. The UV light is irradiated once again. After the upper and lower templates are detached, we can get a complete array of polymer waveguides with built-in 45 mirror face at each end of the waveguide.View Within Article3. Microlensed VCSELOne of the approaches to collimate the light from VCSEL arrays to the waveguide is the use of microlenses 9 and 10. This method offers an increase in coupling efficiency and alignment tolerance. The volume of a polymer drop to fabricate these lenses is approximately a few tens of picoliters. We are able to control the size of the microlenses by controlling the amount of the polymer drops and by controlling the viscosity of the materials. UV curable polymer is used for inkjetting, of which the viscosity and the refractive index are 300cps and 1.51 at 850nm wavelength. Shows one of the microlensed VCSEL array and microlensed VCSEL has a microlens formed by the inkjetting method on the aperture of VCSEL. Inkjetting of UV curable resin on the VCSEL, lens material is aligned automatically on the aperture of VCSEL. Shows a view of the system where the output power from the microlensed VCSEL arrays is measured for their divergence. The divergence angle of the laser light from the VCSEL is shown to become narrower by using microlenses by the collimating effect pf the light from VCSEL. Because of the microlens, the higher order modes from the VCSEL are suppressed by the cavity effect 10. The emitted output from the VCSEL cavity is reflected back by microlens layer and is focused on the VCSEL cavity. During this process, the divergence angle of the VCSEL is reduced. In this case, the divergence angle of the VCSEL decreased from 18 to 15 after forming microlens. We conducted simulation study about the coupling efficiency between VCSEL and the waveguide by using the ray tracing method. As the divergence angle of the VCSEL was put into the calculation, the coupling efficiency of the VCSEL with microlens was found to be 0.44dB is 0.96dB which were better than that of VCSEL without microlens as 1.40dB. Here dimension of waveguide is 50m width, 50m height and 7cm length. Refractive indices of the core and the cladding are 1.47 and 1.45, respectively, at 850nm wavelength. The distance between the VCSEL and the waveguide is 100m.View Within Article4. Passive alignmentSolder ball array and pin array are placed on the electrical sub-boards to bond the O-PCB and the electrical sub-boards with high precision. For precision alignment, solder ball array in diameter of 450m are used to thermally attach to the chip module. The solder ball array can be used for vertically alignment between the main O-PCB and the sub-boards within a mismatch below 10m. The size of the solder ball is 500m on average with standard error of 5m.Two types of pin arrays are used. One array with diameter of 1mm is for alignment and the other with diameter of 200m is for electrical interconnection. The 1mm pin array is used for lateral alignment between the main O-PCB and the sub-boards. Because of the impedance match, the pin array of the electrical interconnection is limited. Similar to solder ball array alignment tolerance of the pin array, about 10m, depends on variation of diameter of pin. The size of the pin is 1mm on average with standard error of 10m.We conducted simulation study about the coupling efficiency between the VCSEL-waveguide pair and the waveguide-PD pair by ray tracing. With the variation of misalignment of x, y, and z axis we calculated the coupling efficiencies. From the calculation we obtained the total coupling loss within 2.30dB for the worst case of having position errors as large as 10m in the xz axis and in the y axis, respectively. For example, when the position misalignment is 10m in the xz axis and in the y axis, the coupling loss between VCSEL-waveguide is 1.59dB and the coupling loss between VCSEL-waveguide is 0.71dB. From the previous results, one can achieve the alignment between solder ball array and pin array can be achieved for alignment between main O-PCB and sub-boards with precision as about 10m in xz axis and in y axis, respectively. Here the dimension of the waveguide is 50m width and 50m height. The refractive indices