外文翻译终稿

第一篇：外文翻译终稿

探析招聘求职网站的发展 对人们的组织文化的看法产生的影响

1摘 要：公司企业在利用传统招聘媒体时，通常是单靠他们的职位空缺，有限的向求职者提供信息。招聘网站的成立与发展，在另一方面，允许有意申请两个或是多个职位的求职者提供有关公司企业的信息。然而，很少有人研究人们关于招聘网站存在的印象。本课题研究了招聘网站的各个方面，可能会导致求职者对组织文化的看法。结果表明，网站设计功能和组织的价值观，政策，奖励和目标的信息，组织文化影响观众的看法。

关键词：网络招聘,在线招聘;网络招聘,招募品德的网站,组织文化。

1引言

越来越多的公司地将互联网作为招聘员工的可行及有吸引力的工具。最近的一项调查研究表明证明了一点，互联网招募是许多不同行业的人力资源专业人士的首选媒介。同样，其他调查结果表明，来自公营和私营的公司招聘，人事部门使用互联网比任何其他的人力资源管理活动更为频繁。这与公司越来越多地依赖互联网上的招聘成果有着明显的影响，因为相比与传统招聘媒体在其官方招聘网站提供更为具体详明的信息，它使得这些行为更为可行。也是出于这个原因，招聘网站通常包括的信息有如下部分，例如员工推荐，利益的信息，公司的价值观和报表等。潜在申请人提供有关公司的形象的方法之一是通过对组织文化看法的宣传。组织文化的看法直接影响个人与组织的契合度，随后影响潜在求职者的自主选择公司职位。然而很少有研究存在于，怎样的申请形式在招聘网站上展现关于组织文化的看法。这种探索性研究在于试图确认招聘网站如何影响人们关于组织文化的看法。

2在线招聘：组织战略和优势

Phillip W.Braddy、Adam W.Meade、Christina M.Kroustalis，Journal of Business and Psychology, Vol.20, No.4, Summer 2006 通过互联网招募的组织主要有两种渠道吸引求职者。首先，企业可以依靠第三方招聘网站发布招聘广告（例如，HotJobs.com，Monster.com）。招聘启事网站（也称为“工作板”）向潜在的求职者提供一个信息交流中心，寻找适合他们的资历和满足他们的需求的职位。因此，工作板的能力是向有意在不同的公司中申请不同的职位的第三方平台。虽然使用的第三方网站，可以大大提高招聘广告阅读浏览量和浏览人数，以及不同地理位置时间区域的不同群体在线寻找就业，但是信息的提供量一般是有限的。这样的事实要归功于，大多数第三方工作平台会基于招聘广告的内容列出相关的金额收费。虽然有时求职者会直接进入各自的雇用公司的网站提出职位的申请，在许多情况下，求职者必须通过第三方平台与招聘单位间接接触。第二种选择是公司组织建立和维护自己的招聘官方网站，发布目前有关该公司的招聘广告和其他的公司信息。这后一种是与最有可能也是有效的第三方平台一起使用时的选择。最近的一项调查表明，超过90％的美国大型公司企业组织保持着自己的官方招聘网站。这些专门招聘的网站，有几个优点。首先，公司企业组织的官方网页上发布的信息内容成本是比工作板上便宜。信息内容可以是各不相同，官方网页可以发布有关员工福利，公司的价值观，公司的简短历史，和其他内容的信息，试图创造一个积极的印象，保持一个良好的招聘形象。一个官方组织的招聘网站上的信息的总金额比招聘第三方平台节省。同时一个主要好处是，职位申请人可以获取更多信息，关于组织文化或是其他关于求职单位的方方面面，有助于更好地了解以及做出有关就业的决定。此外，这种类型的网络招聘可以降低成本，尽量减少所需的时间，成功招募潜在人才，同时表现了创建招聘网站使用网络招聘的公司是精通技术的。最后，网上的招聘求职者，让他们直接在网上递交申请材料相应的使成本降低。总之，我们相信，公司将继续利用互联网作为在未来的主要招聘媒介。我们也相信，该公司将继续维持除了使用第三方平台，并对其官方网站的依赖。

3信息理论和申请人的文化感知的形成

从经济学的研究上，信息理论是的买方和卖方拥有和信息的作用已经被采纳，解释潜在申请人和招募组织之间的相互作用。从本质上讲，这种理论认为，在有关组织的其他信息的情况下，一个潜在的申请人，将吸引周边线索的进行推论。在招聘中，已发现信息理论的相当大的支持，如申请人已被证明有对招聘人 员的看法，依靠的是对租用场地的机构获得的印象。例如，如果一个组织的招聘主管友好的态度，求职者人可以假设，这些都是素质以及整个公司的形象。这是经常性发生的，因为求职者认为招聘人员代表各自的公司。这可能是因为申请人认为招聘人员作为代表其各自的组织。虽然这样的招聘经验在许多情况下可以有信息的价值，当求职者拥有雇用组织的相关认知，这些经验的作用更为重要。我们相信，信息理论可以扩展到互联网，用于解释潜在申请人对组织文化的看法，再浏览招聘网站。例如，如果一个组织的网站，以及结构和有组织的，申请人可以推断，组织价值观。在没有更多有意义的信息，信息理论认为网络招聘网站应提供线索。

4讨论

互联网提供了一个平台来传输大量的有关组织或是求职者的信息的，但已知目前很少有申请人利用这一信息平台。目前的研究状况是，试图确定的招聘网站，可能会涉及到求职者的组织文化观念方面，以解决这方面的不足。这些发现表明，网站的设计特点，组织政策，文化层面的具体引用的信息和其他一些项目都有一定的影响，但在目前的研究使用中，有关网站的内容，在确定什么文化观念与财富榜500强企业的官方网站相关参与发挥了有益的作用。虽然参与者的反应各不相同，综合总结后有三个共同的主题出现。首先，文化维度的具体提及是公司的网站上是典型的置顶部分，与会者表示与某个组织相关联的某一方面的文化是非常受关注的。这一趋势是真实的存在与所有文化层面。其次，使用网站的设计特点是要求高度创新，注重细节，明确团队的发展方向，和多样性的认识。最后，有关组织的政策，明确说明在于传播公司特点以及多样性。

5未来发展趋势

本研究开始提出网站功能和内容，可能与形成求职者的组织文化印象，可以得出：更多的研究在这方面做出任何明确的结论之前是必要的。具体来说，我们希望未来的研究将确定招聘网站的存在与发展具有潜在的对人们关于组织文化的看法的影响。这些研究将允许不同的网站功能和内容因果结论的效力，产生建立各种文化观念。此外，研究需要解决相关的其他问题，例如相对影响组织文化对求职者的工作追求意图相比更为传统的因素，像是工资和福利。最后，未来的研究调查方向通过不同的途径研究，对于一个充满希望又为招聘网站吸引的高素 质的求职者，相对于传统的招聘信息来源的有效性。很明显，在未来互联网将是潜在求职者的一个重要的信息来源。然而，许多问题仍然存在于这一在招聘媒介中。

ORGANIZATIONAL RECRUITMENT WEBSITE EFFECTS ON VIEWERS' PERCEPTIONS OF ORGANIZATIONAL

CULTURE

Phillip W.Braddy Adam W.Meade Christina M.Kroustalis

North Carolina State University

ABSTRACT: When utilizing traditional recruitment media, organizations are typically limited to providing job seekers with information solely on their vacant positions.Organizational recruitment websites, on the other hand, allow organizations to provide prospective applicants with both job descriptions and other information about the organization.However, little research exists regarding the impressions that viewers gain from organizational recruitment websites.The present study identified aspects of recruitment websites that may give rise to job seekers' perceptions of organizational culture.Results indicated that both website design features and information about organizational values, policies, awards, and goals affected viewers' perceptions of organizational culture.KEY WORDS: Internet recruiting;online recruiting;web recruiting;recruit ment websites;organizational culture.INTRODUCTION Many organizations increasingly view the Internet as a viable and attractive tool for recruiting employees(Cober, Brown, Blumental, Doverspike, & Levy, 2000;Harrington, 2002).This is evidenced by recent survey research that indicates the Internet was the preferred medium of HR professionals when recruiting applicants for many positions in diverse industries(Chapman & Webster, 2003).Likewise, results of other surveys suggest that companies from both private and public sectors use the Internet more frequently for recruiting applicants than for any other HRM activity(e.g., Elliot & Tevavichulada, 1999).This increased reliance on the Internet has salient implications for organizations because it enables them to provide much more information on their official recruitment websites than is feasible with traditional recruitment media.Organizations provide this information in hopes that potential applicants favorably view the organization as a potential employer.For this reason, organizational recruitment websites commonly include features such as employee testimonials, benefits information, and organizational values statements.One way in which potential applicants draw conclusions about the organization is via perceptions of the culture of the organization.Perceptions of organizational culture directly affect perceptions of person-organization fit, which can subsequently affect how potential applicants self-select organizations(Judge & Cable, 1997).How ever, very little research exists regarding how applicants form culture perceptions from recruitment websites.Thus, this exploratory study at tempts to identify aspects of websites that influence viewer perceptions of organizational culture impressions.Online Recruiting: Organizational Strategies and Benefits Organizations recruiting via the Internet have two primary avenues to attract viewers into the applicant pool.First, organizations can rely upon third-parties that distribute job advertisements on a job listing website(e.g., HotJobs.com, Monster.com).Job listing websites(a.k.a., “job boards”)have the advantage of providing a clearinghouse for potential job applicants to search across organizations for positions appropriate to their qualifications and that meet their needs.Therefore, job boards have the ability to alert potential applicants to openings in many organizations.While the use of third-party websites or job boards can greatly increase the number of viewers reading the job advertisement and potentially reach a more geographically diverse group of applicants searching for jobs online(Crispin & Mehler, 1997), the amount of information that is available to the applicant is generally quite limited.This can likely be attributed to the fact that most third-party job boards charge fees based on the amount of content listed in the job advertisement.Moreover, although applicants are sometimes provided with direct access to the respective hiring companies' websites(Zusman & Landis, 2002), in many cases applicants must apply to the hiring organization indirectly through the third-party organization(Recruiting, 1999).A second option is for an organization to create and maintain its own official website to present job advertisements and additional information about the company(Zusman & Landis, 2002).This latter option is most likely to be effective when used in conjunction with job boards.One recent survey indicates that over 90% of large U.S.organizations maintain their own official recruiting websites(Cappelli, 2001).These websites, dedicated solely to recruitment, have several advantages.First, content can be posted much more cheaply on the organization's official web page than on a job board.Though content varies consider ably, organizations can post information about employee benefits, organizational values, a brief history of the organization, and additional content to attempt to create a positive impression needed to maintain a favorable recruitment image(Gatewood, Gowan, & Lautenschlager, 1993).The overall amount of information on an official organizational recruitment website is much greater than from a job advertisement alone(Braddy, Thompson, Wuensch, & Grossnickle, 2003).A major benefit of this additional content is that applicants can acquire more information regarding organizational culture, which may facilitate making better informed employment-related decisions.Additionally, this type of web recruiting can reduce costs(Cober et al., 2000;Kay, 2000;Marcus, 2001), minimize the amount of time required to successfully recruit applicants(Web Recruiting Advantages, 2001), and create the perception that companies who use online recruiting are technologically savvy(Fister, 1999).Finally, online recruiting reduces application costs for job seekers by allowing them to directly submit application materials online(Cappelli, 2001;Zusman & Landis, 2002).In short, we believe that companies will continue to utilize the Internet as a primary recruitment medium in the future.We also believe that organizations will continue to maintain and rely upon their official websites in addition to using third party job boards.Signaling Theory and the Formation of Applicant Culture Perceptions Signaling theory was developed from economics research on the role of information possessed by buyer and seller(Spence, 1974)and has been adopted to explain the interaction between potential applicants and recruiting organizations(Rynes, Bretz, & Gerhart, 1991;Rynes & Miller, 1983;Spence, 1973).In essence, this theory suggests that in the absence of other information about an organization, a potential applicant will draw inferences about the organization based on peripheral cues.In the recruitment context, considerable support for signaling theory has been found as applicants have been shown to rely on perceptions of recruiters to derive their impressions of hiring organizations(Goltz & Giannantonio, 1995;Rynes et al., 1991;Rynes & Miller, 1983;Turban, 2001;Turban, Forret, & Hendrickson, 1998).For example, if an organization's recruiter was perceived as both competent and friendly, applicants may assume that these are defining qualities of the entire organization as well.This likely occurs because applicants view recruiters as being representative of their respective organizations(Rynes & Miller, 1983).Though such recruiting experiences can have signaling value under many circumstances, the role of such experiences is much more significant when applicants possess little knowledge about the hiring organization(Rynes et al., 1991).We believe signaling theory can be extended to the Internet domain to explain how potential applicants form organizational culture perceptions after viewing recruitment websites.For instance, if an organization's website is well structured and organized, applicants may infer that the organization values and possesses such characteristics.In the absence of more meaningful information(e.g., direct knowledge from an incumbent, a site visit, etc.), signaling theory suggests that an Internet recruiting website should provide cues to the viewer about the nature of the organization.DISCUSSION The Internet provides organizations with a tool to transmit large amounts of information about the organization to job seekers, yet very little is currently known about the manner in which applicants utilize this information.The current study sought to address this deficiency by identifying aspects of recruitment websites that may be related to job seekers' organizational culture perceptions.These findings indicate that website design features(e.g., employee testimonials illustrating team work), information about organizational policies(e.g., continuing education programs), specific references to culture dimensions(e.g., “the organization values workers who are creative and innovative”), and other miscellaneous but relevant website content(e.g., listing of organizational awards won)played an instrumental role in determining what culture perceptions participants associated with the Fortune 500 companies whose websites were used in the current study.Though the percentage of participant responses assigned to the aforementioned categories varied considerably across the nine culture dimensions, there were three common themes that emerged.First, the specific references made about culture dimensions(i.e., content)on a company's website was typically one of the top most cited reasons that participants indicated for associating a particular aspect of culture with a given organization.This trend was true for all culture dimensions, excluding emphasis on rewards.Second, the use of website design features was indicated as being highly important for conveying perceptions of innovation, attention to detail, team orientation, and diversity.Finally, clearly stating relevant organizational policies seemed instrumental for transmitting companies' emphases on rewards, supportiveness, and diversity.FUTURE RESEARCH The present study begins to outline website features and content that may be related to the formation of job seekers' organizational culture impressions, but much additional research in this area is needed before any definitive conclusions can be drawn.Specifically, we hope that future researchers will manipulate portions of websites identified in this study as having a potential impact on viewers' perceptions in both con trolled laboratory and field environments.Such studies would permit causal conclusions to be drawn regarding the efficacy of different website features and content for creating various culture perceptions.In addition, research is needed to address the relative effects of organizational culture impressions on applicants' job-pursuit intentions when compared to more traditional factors, such as pay and benefits.Finally, another promising yet slightly different avenue for future research is to investigate the effectiveness of organizational recruitment websites in attracting top quality applicants relative to traditional recruitment sources(e.g., such as recruiters and newspaper advertisements).It is clear that the Internet will be a significant source of information for potential job applicants in the future.However, many questions remain regarding the precise role of this medium in the recruitment process.

第二篇：外文翻译

当今时代是一个自动化时代，交通灯控制等很多行业的设备都与计算机密切相关。因此，一个好的交通灯控制系统，将给道路拥挤，违章控制等方面给予技术革新。随着大规模集成电路及计算机技术的迅速发展，以及人工智能在控制技术方面的广泛运用，智能设备有了很大的发展，是现代科技发展的主流方向。本文介绍了一个智能交通的系统的设计。该智能交通灯控制系统可以实现的功能有：对某市区的四个主要交通路口进行控制：个路口有固定的工作周期，并且在道路拥挤时中控制中心能改变其周期：对路口违章的机动车能够即时拍照，并提取车牌号。在世界范围内，一个以微电子技术，计算机和通信技术为先导的，一信息技术和信息产业为中心的信息革命方兴未艾。而计算机技术怎样 与实际应用更有效的结合并有效的发挥其作用是科学界最热门的话题，也是当今计算机应用中空前活跃的领域。本文主要从单片机的应用上来实现十字路口交通灯智能化的管理，用以控制过往车辆的正常运作。

研究交通的目的是为了优化运输，人流以及货流。由于道路使用者的不断增加，现有资源和基础设施有限，智能交通控制将成为一个非常重要的课题。但是，智能交通控制的应用还存在局限性。例如避免交通拥堵被认为是对环境和经济都有利的，但改善交通流也可能导致需求增加。交通仿真有几个不同的模型。在研究中，我们着重于微观模型，该模型能模仿单独车辆的行为，从而模仿动态的车辆组。

由于低效率的交通控制，汽车在城市交通中都经历过长时间的行进。采用先进的传感器和智能优化算法来优化交通灯控制系统，将会是非常有益的。优化交通灯开关，增加道路容量和流量，可以防止交通堵塞，交通信号灯控制是一个复杂的优化问题和几种智能算法的融合，如模糊逻辑，进化算法，和聚类算法已经在使用，试图解决这一问题，本文提出一种基于多代理聚类算法控制交通信号灯。

在我们的方法中，聚类算法与道路使用者的价值函数是用来确定每个交通灯的最优决策的，这项决定是基于所有道路使用者站在交通路口累积投票，通过估计每辆车的好处(或收益)来确定绿灯时间增益值与总时间是有差异的，它希望在它往返的时候等待，如果灯是红色，或者灯是绿色。等待，直到车辆到达目的地，通过有聚类算法的基础设施，最后经过监测车的监测。

我们对自己的聚类算法模型和其它使用绿灯模拟器的系统做了比较。绿灯模拟器是一个交通模拟器，监控交通流量统计，如平均等待时间，并测试不同的交通灯控制器。结果表明，在拥挤的交通条件下，聚类控制器性能优于其它所有测试的非自适应控制器，我们也测试理论上的平均等待时间，用以选择车辆通过市区的道路，并表明，道路使用者采用合作学习的方法可避免交通瓶颈。

本文安排如下：第2部分叙述如何建立交通模型，预测交通情况和控制交通。第3部分是就相关问题得出结论。第4部分说明了现在正在进一步研究的事实，并介绍了我们的新思想。

The times is a automation times nowadays,traffic light waits for much the industey equipment to go hand in hand with the computer under the control of.Therefore,a good traffic light controls system,will give road aspect such as being crowded,controlling against rules to give a technical improvement.With the fact that the large-scale integrated circuit and the computer art promptness develop,as well as artificial intelligence broad in the field of control technique applies,intelligence equipment has had very big development,the main current being that modern science and technology develops direction.The main body of a book is designed having introduccd a intelligence traffic light systematically.The function being intelligence traffic light navar’s turn to be able to come true has：The crossing carries out supervisory control on four main traffic of some downtown area;Every crossing has the fixed duty period,charges centrefor being able to change it’s period and in depending on a road when being crowded;The motro vehicle breaking rules and regulations to the crossing is able to take a photo immediately,abstracts and the vehicle shop sign.Within world range ,one uses the microelectronics technology,the computer and the technology communicating by letter are a guide’s,centering on IT and IT industry information revolution is in the ascendant.But,how,computer art applies more effective union and there is an effect’s brought it’s effect into play with reality is the most popular topic of scientific community,is also that computer applications is hit by the unparalleled active field nowadays.The main body of a book is applied up mainly from slicing machine’s only realizing intellectualized administration of crossroads traffic light,use operation in controlling the vehicular traffic regularity.Transportation research has the goal to optimize transportation flow of people and goods.As the number of road users constantly increases, and resources provided by current infras-tructures are limited, intelligent control of traffic will become a very important issue in thefuture.However, some limitations to the usage of intelligent tra?c control exist.Avoidingtraffic jams for example is thought to be beneficial to both environment and economy, butimproved traffic-flow may also lead to an increase in demand [Levinson, 2003].There are several models for traffic simulation.In our research we focus on microscopicmodels that model the behavior of individual vehicles, and thereby can simulate dynam-ics of groups of vehicles.Research has shown that such models yield realistic behavior[Nagel and Schreckenberg, 1992, Wahle and Schreckenberg, 2001].Cars in urban traffic can experience long travel times due to inefficient traffic light con-trol.Optimal control of traffic lights using sophisticated sensors and intelligent optimizationalgorithms might therefore bevery beneficial.Optimization of traffic light switching increasesroad capacity and traffic flow, and can prevent tra?c congestions.Traffic light control is acomplex optimization problem and several intelligent algorithms, such as fuzzy logic, evo-lutionary algorithms, and reinforcement learning(RL)have already been used in attemptsto solve it.In this paper we describe a model-based, multi-agent reinforcement learningalgorithm for controlling traffic lights.In our approach, reinforcement learning [Sutton and Barto, 1998, Kaelbling et al., 1996]with road-user-based value functions [Wiering, 2000] is used to determine optimal decisionsfor each traffic light.The decision is based on a cumulative vote of all road users standingfor a traffic junction, where each car votes using its estimated advantage(or gain)of settingits light to green.The gain-value is the difference between the total time it expects to waitduring the rest of its trip if the light for which it is currently standing is red, and if it is green.The waiting time until cars arrive at their destination is estimated by monitoring cars flowingthrough the infrastructure and using reinforcement learning(RL)algorithms.We compare the performance of our model-based RL method to that of other controllersusing the Green Light District simulator(GLD).GLD is a traffic simulator that allows usto design arbitrary infrastructures and traffic patterns, monitor traffic flow statistics such asaverage waiting times, and test different traffic light controllers.The experimental resultsshow that in crowded traffic, the RL controllers outperform all other tested non-adaptivecontrollers.We also test the use of the learned average waiting times for choosing routes of cars through the city(co-learning), and show that by using co-learning road users can avoidbottlenecks.

第三篇：外文翻译

设计一个位于十字路口的智能交通灯控制系统

摘要：本文模型使用模糊本体的交通灯控制域，并把它应用到控制孤立十字路口。本文最重要的目的之一是提出一个独立的可重复使用的交通灯控制模块。通过这种方式，增加软件的独立性和为其他的软件开发活动如测试和维护，提供了便利。专家对本体论进行手动的开发和评估。此外，交通数据提取和分类路口使用的人工神经网络的图像处理算法。根据预定义的XML架构，这种信息转化为XML实例映射到适合使用模糊推理引擎的模糊规则的模糊本体。把本系统的性能与其他类似的系统性能进行比较。比较结果显示：在所有的交通条件下，在每个周期中，对每辆车它有低得多的平均延迟时间与其他的控制系统相比。

关键词:模糊本体,智能代理,智能交通系统(ITS),交通信号灯控制(TLC),孤立的十字路口,图像处理,人工神经网络

1.引言

作为城市交通增加的结果,道路网络的能力有限和发展交通工具和方法的技术方面，许多实体，关系，情况和规则已经进入交通灯控制域和转化成为一个知识领域。这个领域的建模知识帮助交通代理和应用有效地管理关于实时条件下的交通。全面知识建模领域的一个最合适的方法是使用本体概念。“本体论是一个正式的、明确的一个共享的概念化的规范。以前的模型是基本的本体建设的基础，为下列建立一个共享的语义丰富的知识域。除了本体作为概念化的形式主义的重要性，它有可能超过所代表的数据。这种能力将提高有关性能的决定和其他非智能系统的功能特点。在近年来，本体论上的研究正成为一个新的热点话题在不同的活动，如人工智能，知识管理，语义网络，电子商务和几个其他应用领域。这些领域之一是智能交通系统。一些努力已制成这个通过展示和使用本体检测交通领域拥塞，管理非城市道路气象事件，驾驶阿德福—索里系统，共享和整合一个智能交通系统。本文的目的是介绍一个红绿灯有效控制孤立交叉口这方面的知识重用的控制本体。这种新的办法适用于智能代理使用知识决策模糊。该系统采用的图像来自安装了监控摄像机拍摄的路口。这些图像处理利用图像处理算法和神经网络的方法，然后发送到一个智能代理。第2节中，我们将简要地解释了在这项工作中运用的技术包括seman-TIC网络技术，智能代理技术和交通的回地面光控制方法。在第3节，新的系统架构是基于分层语义网络架构。第4节介绍交通灯控制的模糊本体的建设。第五节从路口提取的图像信息解释。在第6节，智能系统的运作被完整描述，最后在第7节对所提出的方法进行评估，对结论进行阐述。

2.背景

本节说明在这项工作中的应用技术包括语义网络技术，特别本体和模糊本体。此外，国家的交通灯控制的艺术方法是简要介绍。2.1.语义网络技术

语义网络被定义为当前Wed的延伸，这些网站的信息都给出明确的含义;使电脑与人更好的合作。有几层语义Web的建议源自伯纳斯滞后阶段。在此类别中的所有规则如表1所示。图.4显示输出模式的示意图。本次评选有助于智能系统，以确定下一步的阶段测序。

另一种模糊的规则类别涉及估计优化周期时间。这些规则的模糊变量是天气条件，时间，每天平均车辆拥堵情况。出于这个原因，60个模糊规则被定义了。从气象研究所取得气象条件。日期和时间也是在交通专家的知识的基础上以模糊变量形式预先定义的。图5显示日期，时间和周期时间的隶属函数。当天的参数是在日历基础上基于假期和正常的一天与周期时间量的关系预定义的。例如，假期期间的周期时间是较平日少。因此，平日的隶属度比假期多。

例如一个阶段选型的模糊规则如下所述：“如果一个路口的类型是四的方式，平均车辆拥堵低，平均行人拥堵是中等，然后相类型是简单的两阶段”。此外，为周期时间估计的模糊规则表示如下：“如果天气条件是晴天，时间是早晨，天是正常的，平均车辆拥堵是低，则周期时间短”。在此类别中的所有规则都列在附录A。

在此步骤结束时，应该对交通灯逻辑控制的项目的有效性进行评估。此功能是使用专家的意见。评价过程的主要目的是显示发展的本体和其相关的软件环境的用处。虽然所有的信息，尤其是交通灯控制规则已提取国际标准和科学交通文学，专家的知识优势是他们最后的正确性验证标准。所有模糊规则，包括优化周期时间和相位类型的规则，在这个过程中，准备以调查问卷形式和展现给一些专家包括从德黑兰警察局交通上校和两名来自德黑兰的交通组织工程师。由于德尔菲专家的意见，约有84％的淘汰型规则和优化周期时间的87％被接受。此外，所有交通逻辑控制的元素包括概念，关系，属性和公理都被这些专家进行了评估和验证。我们评估逻辑交通控制是基于理论知识的。在这个过程中进行了两项活动，包括检查的要求和能力的问题，并在目标应用环境测试本体。由于逻辑交通控制已建成的基础上，如指定要求优化循环时间，逐步淘汰型，交通的移动和优化绿灯时间，每个阶段的序列中，第一项活动是最好的结果。逻辑交通控制满足所有的交通灯控制的需求，并能回答的能力问题。绩效评估机制，可以支持这种说法。在部分实验结果我们验证了这一过程。

第四篇：外文翻译

中原工学院毕业设计（论文）译文

超声测距系统设计

原文出处：传感器文摘 布拉福德：1993年第13页

摘要：超声测距系统技校在工业场车辆导航水声工程等领域都具有了广泛的应用价值，目前已应用于物理测量，机器人自动导航以及空气中与水下的目标探测、识别定位等场合，因此，深入研究超声的探测理论和方法具有重要的实践意义，为了进一步提高测量的精确度，满足工程人员对测量精度测距量程和测距仪使用的要求，本文研制了一套基于单片机的使拱式超声测距系统。关键词：超声波 测距仪 单片机

1、前言

随着科技的发展，人们生活水平的提高，城市发展建设加快，城市给排水系统也有较大发展，其状况不断改善，但是，由于历史原因合成时间性的许多不可预见因素，城市给排水系统，特别是排水系统往往落后于城市建设，因此，经常出现开挖已经建设好的建筑设施来改造排水系统的现象。城市污水给人们带来的困扰，因此箱的排污疏通对大城市给排水系统污水理，人们生活舒适显得非常重要。而设计研制箱涵排水疏通移动机器人的自动控制系统，保证机器人在箱涵中自由排污疏通，是箱涵排水系统疏通机器人的设计研制的核心部分，控制系统核心部分就是超声波测仪的研制。因此，设计好的超声波测距仪就显得非常重要了。

1.1课题背景

随着经济的发展与汽车科学技术的进步，公路交通呈现出行驶高速化、车流密集化和驾驶员非职业化的趋势。同时，随着汽车工业的飞速发展，汽车的产量和保有量都在急剧增加。但公路发展、交通管理却相对落后，导致了交通事故与日剧增，城市里尤其突出。智能交通系统ITS是目前世界上交通运输科学技术的前沿技术，它在充分发挥现有基础设施的潜力，提高运输效率，保障交通安全，缓解交通赌塞，改善城市环境等方面的卓越效能，已得到各国政府的广泛关注。中国政府也高度重视智能交通系统的研究开发与推广应用。汽车防撞系统作为ITS 发展的一个基础，它的成功与否对整个系统有着很大的作用。从传统上说，汽车的安全可以分为两个主要研究方向:一是主动式安全技术，即防止事故的发生，该种方式是目前汽车安全研究的最终目的;二是被动式安全技术，即事故发生后的乘员保护。目前汽车安全领域被动安全研究较多，主要从安全气囊、ABS(防抱死系统)和悬架等方面着手，以保证驾乘人员的安全。从经济性和安全性两方面来说，中原工学院毕业设计（论文）译文

这些被动安全措施是在事故发生时刻对车辆和人员进行保护，有很大的局限性，因而车辆的主动安全研究尤为重要，引出了本文研究的基于单片机的超声波测距系统。这个系统是一种可向司机预先发出视听语音信号的探测装置。它安装在汽车上，能探测企图接近车身的行人、车辆或周围障碍物;能向司机及乘员提前发出即将发生撞车危险的信号，促使司机采取应急措施来应付特殊险情，避免损失。

1.2 课题设计的意义

随着现代社会工业化程的发展，汽车这一交通工具正为越来越多的人所用，但是随之而来的问题也显而易见，那就是随着车辆的增多，交通事故的频繁发生，由此导致的人员伤亡和财产损失数目惊人。对于公路交通事故的分析表明，80%以上的车祸事由于驾驶员反应不及所引起的，超过65%的车辆相撞属于追尾相撞，其余则属于侧面相撞。奔驰汽车公司对各类交通事故的研究表明：若驾驶员能够提早1S 意识到有事故危险并采取相应的正确措施，则绝大多数的交通事故都可以避免。因此，大力研究开发如汽车防撞装置等主动式汽车辅助安全装置，减少驾驶员的负担和判断错误，对于提高交通安全将起到重要的作用。显然，此类产品的研究开发具有极大的实现意义和广阔的应用前景。

1.3超声波测距在汽车上应用的介绍

超声波倒车测距仪(俗称电子眼)是汽车倒车防撞安全辅助装置，能以声音或者更为直观的数字形式动态显示周围障碍物的情况。其较早的产品是用蜂鸣器报警，蜂鸣声越急，表示车辆离障碍物越近。后继的产品可以显示车后障碍物离车体的距离。其大多数产品探测范围在0.4～1.5m，有的产品能达到0.35～2.5m，并有距离显示、声响报警、区域警示和方位指示，有些产品还具备开机自检功能。目前市场上还出现了具有语音报警功能的产品。这些产品存在的主要问题是测量盲区大，报警滞后，未考虑汽车制动时的惯性因素，使驾驶者制动滞后，抗干扰能力不强，误报也较多。汽车防撞雷达之所以能实现防撞报警功能，主要有超声波这把无形尺子, 它测量最近障碍物的距离, 并告诉给车主。其实超声测距原理简单: 它发射超声波并接收反射回波, 通过单片机计数器获得两者时间差t, 利用公式S=Ct/2计算距离, 其中S为汽车与障碍物之间的距离, C为声波在介质中的传播速度。

本文介绍的超声测距系统共有2只超声波换能器(俗称探头),分别布置在汽车的后左、后右2个位置上。能检测前进和倒车方向障碍物距离, 通过后视镜内置的

中原工学院毕业设计（论文）译文

显示单元显示距离和方位, 发出一定的声响, 起到提示和警戒的作用。系统采用一片STC89C52单片机对两路超声波信号进行循环采集。超声波是指频率高于20HHZ的机械波。为了以超声波作为检测手段，必须产生超生波和接收超声波。完成这种功能的装置就是超声波传感器，习惯上称为超声波换能器或超声波探头。超声波传感器有发送器和接收器，但一个超声波传感器也可具有发送和接收声波的双重作用。超声波传感器是利用压电效应的原理将电能和超声波相互转化，即在发射超声波的时候，将电能转换，发射超声波；而在收到回波的时候，则将超声振动转换成电信号。超声波测距的原理一般采用渡越时间法。首先测出超声波从发射到遇到障碍物返回所经历的时间，再乘以超声波的速度就得到二倍的声源与障碍物之间的距离。测量距离的方法有很多种，短距离的可以用尺，远距离的有激光测距等，超声波测距适用于高精度的中长距离测量。因为超声波在标准空气中的传播速度为331.45米/秒，由单片机负责计时，单片机使用12.0M晶振，所以此系统的测量精度理论上可以达到毫米级。由于超声波指向性强，能量消耗缓慢，在介质中传播距离远，因而超声波可以用于距离的测量。利用超声波检测距离，设计比较方便，计算处理也较简单，并且在测量精度方面也能达到要求。超声波发生器可以分为两类：一类是用电气方式产生超声波，一类是用机械方式产生超声波。本设计属于近距离测量，可以采用常用的压电式超声波换能器来实现触发单元。

利用超声波测距的工作，就可以根据测量发射波与反射波之间的时间间隔，从而达到测量距离的作用。其主要有三种测距方法：

（1）相位检测法，相位检测法虽然精度高，但检测范围有限；

（2）声波幅值检测法，声波幅值检测法易受反射波的影响；

（3）渡越时间检测法，渡越时间检测法的工作方式简单，直观，在硬件控制和软件设计上都非常容易实现。其原理为：检测从发射传感器发射超声波，经气体介质传播到接收传感器的时间，这个时间就是渡越时间。本设计的超声波测距就是使用了渡越时间检测法。在移动车辆中应用的超声波传感器，是利用超声波在空气中的定向传播和固体反射特性（纵波），通过接收自身发射的超声波反射信号，根据超声波发出及回波接收的时间差和传播速度，计算传播距离，从而得到障碍物到车辆的距离。

中原工学院毕业设计（论文）译文 超声波测距原理

2.1 压电式超声波发生器原理

压电式超声波发生器实际上是利用压电晶体的谐振来工作的。超声波发生器内部结构，它有两个压电晶片和一个共振板。当它的两极外加脉冲信号，其频率等于压电晶片的固有振荡频率时，压电晶片将会发生共振，并带动共振板振动，便产生超声波。反之，如果两极板间未加电压，当共振板接收到超声波时，将压迫压电晶片做振动，将机械能转换为电信号，这是它就成为超声波接收器了。

测量脉冲到达时间的传统方法是以拥有固定参数的接收信号开端为基础的。这个信号恰恰选于噪音水平之上，然而脉冲到达时间被定义为脉冲信号刚好超过界限的第一时刻。一个物体的脉冲强度很大程度上取决于这个物体的自然属性尺寸还有它与传感器的距离。进一步说，从脉冲起始点到刚好超过界限之间的时间段随着脉冲的强度而改变。结果，一种错误便出现了——两个拥有不同强度的脉冲在不同时间超过界限却在同一时刻到达。强度较强的脉冲会比强度较弱的脉冲超过界限的时间早点，因此我们会认为强度较强的脉冲属于较近的物体。

2.2 超声波测距原理

超声波发射器向某一方向发射超声波，在发射时刻的同时开始计时，超声波在空气中传播，途中碰到障碍物就立即返回来，超声波接收器收到反射波就立即停止计时。超声波在空气中的传播速度为340m/s，根据计时器记录的时间t，就可以计算出发射点距离障碍物的距离(s)，即：s=340t/2

中原工学院毕业设计（论文）译文

3、超声波测距系统的电路设计

系统的特点是利用单片机控制超声波的发射和超声波自发射至接受往返时间的计时，单片机选用C51，经济易用，且片内有4K的ROM，便于编程。电路的原理如图1所示。

图1 电路原理图

中原工学院毕业设计（论文）译文

3.1 40kHz脉冲的产生与超声波发射

测距系统中的超声波传感器采用UCM40的压电陶瓷，它的工作电压是40kHz的脉冲信号，这由单片机执行下面的程序来产生。puzel：mov 14h，#12h

here： cp1.0；

nop；

nop；

nop；

djnz 14h，here；

Ret

前方测距电路的输出端接单片机P1.0端口，单片机执行上面的程序后，在P1.0端口输出一个40khz的脉冲信号，经过三极管T放大，驱动超声波发射头UCM40T，发出40khz的脉冲超声波，且持续发射200ms。右侧合作侧测距电路的输入端分别接P1.1和P1.2端口，工作原理和前方测距电路相同。

超声波发射持续200ms 输出40kHz方波

3.2 超声波的接收与处理

接收头采用与发射头配对的UCM40R，将超声波调制脉冲变为电压信号，经运算放大器ic1a和ic1b两级放大后加至IC2,。IC2是带有锁定环的音频译码集成块LM567，内部压控振荡器的中心频率f0=1/1.1R8C3，电容C4决定其带宽。调节R8在发射的载频上，则LM567输入信号大于25mv，输出端8脚由5由高电平跃变为低电平，作为中断请求信号，送至单片机处理。

前方测距电路的输出端接至单片机INT0端口，中断优先级最高，左、右测距电路的输出通过与门IC3A的输出接单片机的INT1端口，同时单片机P1.3和P1.4接到IC3A的输入端，中断源的识别由程序查询来处理，中断优先级为先右后左。部分源程序如下： receive1：push psw

push acc

clr ex1；关中断源1

jnb p1.1，right;P1.1引脚为0，转至右侧距电路中断服务程序

jnb p1.2,left;P1.2 引脚为0，转至左测距中断电路服务程序 returne：SETB EX1；

开外部中断1

pop acc

中原工学院毕业设计（论文）译文

pop psw

reti right：

...；

右测距电路中断服务程序入口

ajmp return

left：

...；

左测距电路中断服务程序入口

ajmp return

3.3 计算超声波传播时间

在启动发射电路的同时启动单片机内部的定时器T0，利用定时器的计数功能，记录超声波发射的时间和受到反射波的时间。当收到超声波反射波时，接受电路输出端产生一个负跳变，在INT0或INT1端产生一个中断请求信号，单片机响应外部中断请求，执行外部中断服务子程序，读取时间差，计算距离。其部分源程序如下：

RECEIVEO: PUSH PSW

PUSH ACC CLR EX0;

关外部中断0 读取时间值

MOV R7,TH0;MOV R6,TL0 CLR C MOV A,R6 SUBB A,#0BBH;MOV 31H,A;MOV A,R7 SUBB A,#3CH MOV 30H,A SETB EX0;POP ACC

POP PSW

RETI 对于一个平坦的目标，测量距离包括两个阶段：粗糙的测量和精细的测量。第一步：脉冲的传送产生一种简单的超声波

第二步：根据公式改变回波放大器的获得量直到回拨被检测到。第三步：检测两种回波的振幅与过零时间。

计算时间值 存储结果

开外部中断0

中原工学院毕业设计（论文）译文

第四步：设置回波放大器的所得规格输出，假定是3v。通过脉冲的周期设置下一个脉冲。根据第二部的数据设定时间窗。

第五步：发射两窜脉冲产生干扰波。测量过零时间与回波振幅。如果逆向发生在回波中，决定要不通过在低气压插入振幅。

第六步：通过公式计算距离y。

中原工学院毕业设计（论文）译文

4、超声波测距系统的软件设计

软件分为俩部分，主程序和中断服务程序。主程序完成初始化工作、各路超声波发射和接收顺序的控制。定时中断服务子程序完成三方向超声波的轮流发射，外部中断服务子程序主要完成时间值的读取、距离计算、结果的输出等工作。

中原工学院毕业设计（论文）译文

5、结论

对所要求测量范围30cm-200cm内的平面物体做了多次测量发现，其最大误差为1.5cm，且重复性好。可见基于单片机设计的超声波测距系统具有硬件结构简单、工作可靠、测量误差小等特点。因此，它不仅可用于移动机器人，还可以用在其他检测系统中。

思考：至于为什么不用接收管做放大电路，因为放大倍数搞不好，集成放大电路，还带自动电平增益控制，放大倍数为76db，中心频率是38k到40k，刚好是超声波传感器的谐振频率。

中原工学院毕业设计（论文）译文

参考文献

1.Fox，J.D.，Khuri-Yakub，B.T.and Kino，G.S.，“High Frequency Acoustic Wave Measurement in Air”，in Proceedings of IEEE 1983 Ultrasonic Symposium，October 31-2 November，1983，Atlanta，GA，pp.581-4.2.Martin Abreu，J.M.，Ceres,R.And Freire,T.,“Ultrasonic Ranging: Envelope Analysis Gives Improved Accuracy”,Sensor Review, Vol.12 No.1,1992,pp.17-21.3.Parrilla， M., Anaya,J.J and Fritsch C.,‖Digital Signal Processing Techniques for High Accuracy Ultrasonic Range Measurement:,IEEE Transactions: Instrumentation and Measurement.Vol.40 No.4, August 1991,pp.750-63.4.Canali, C., Cicco, G.D., Mortem, B., Prudenziati, M., and Taron, A., ―A Temperature Compensated Ultrasonic Sensor Operating in Air for Distance and Proxinmity Measurement‖, IEEE Trasaction on Industry Electronics, Vol, IE-29 No.4,1982, pp.336-41.5.Martin, J.M., Ceres, R., Calderon, L and Freire, T., ‖Ultrasonic Ranging Gets Themal Correction‖, Sensor Review, Vol, 9 No.3, 1989,pp.153-5.中原工学院毕业设计（论文）译文

Ultrasonic ranging system design Publication title: Sensor Review.Bradford:1993.Vol.13 ABSTRACT: Ultrasonic ranging technology has wide using worth in many field, such as the industrial locale, vehicle navigation and sonar engineering.Now it has been used in level measurement, self-guided autonomous vehicles, fieldwork robots automotive navigation, air and underwater target detection, identification ,location and so on.So there is an important practicing meaning to learn the ranging theory and ways deeply.To improve the precision of the ultrasonic ranging system in hand, satisfy the request of the engineering personal for the precision,the bound and the usage, a portable ultrasonic ranging system based on the single chip processor was developed.Keywords: Ultrasound r, Ranging System, Single Chip Processor

1.Introductive With the development of science and technology, the improvement of people’s standard of living, speeding up the development and construction of the city.Urban drainage system have greatly developed their situation is constantly improving.However, due to historical reasons many unpredictable factors in the synthesis of her time, the city drainage system.In particular drainage system often lags behind urban construction.Therefore, there are often good building excavation has been building facilities to upgrade the drainage system phenomenon.It brought to the city sewage, and it is clear to the city sewage and drainage culvert in the sewage treatment system.Confort is very important to people’s lives.Mobile robots designed to clear the drainage culvert and the automatic control system Free sewage culvert clear guarantee robot, the robot is designed to clear the culvert sewage to the core.Control System is the core component of the development of ultrasonic range finder.Therefore, it is very important to design a good ultrasonic range finder.1.1 subject background

With the development of economy and car scientific and technological progress, highway traffic presents driving fast pace, traffic dense is changed and the driver not professional trend.At the same time, along with the rapid development of auto industry, automobile yield and quantities are increased dramatically.But road development，中原工学院毕业设计（论文）译文

transportation management is relatively backward, leading to a large number of traffic accidents in some cities, especially prominent.Intelligent transportation system in the world, ITS transportation science and technology of advanced technology, ITS exerting existing infrastructure of potential, enhance the transport efficiency, safeguard traffic safety and ease traffic wager plug, improving urban environment aspects of outstanding performance, has received the governments of widespread concern.The Chinese government is also highly intelligent transportation system of the development and popularization applications.The automotive anti-collision system as ITS development of a base, ITS success to the whole system has a very significant role.Traditionally, auto safety said can be divided into two main research direction: first,it is active safety technology, including the prevention of accidents, the way is now automotive safety research ultimate purpose;second, it is passive safety technique, namely the occupant protection after the accident.Now automotive safety field passive safety more research, mainly from the airbag, ABS(antilock brakes)and suspension from the aspects such as to ensure safety of personnel rides.From the economic and safety two ways, these passive safety measures is the accident of vehicle and personnel moments protection, with great limitations, thus vehicle active safety research is particularly important, leads to a of this study is based on single chip ultrasonic ranging system.This system is a kind of can advance to the driver issued audio-visual speech signal detection devices.It is installed in cars that can detect trying to approach the body of a car pedestrians and vehicles or around obstacles, Can send to the driver and crew imminent danger ahead of the signal, prompting a crash drivers take emergency measures to cope with special danger, avoid the loss.1.2 question design significance

Along with the development of modern society industrialization process, car this traffic tools are used for more and more people, but any problem has obvious that along with the increase in vehicles, traffic accident, which led to the frequent occurrence of casualties and property losses number astonishing.For highway traffic accident analysis showed that more than 80% of the accident due to the driver reaction inferior things, caused more than 65% of vehicle collision, the rest belongs to tracing cauda collided belongs to the side collision.Mercedes-benz Automobile Company for all kinds of traffic accident research shows that: if the driver can early 1S are aware

中原工学院毕业设计（论文）译文

that a accident risk and take the appropriate corrective measures, the overwhelming majority of traffic accidents can be avoided.Therefore, vigorously research and development as the automotive anti-collision device etc active car auxiliary safe device, reduce the burden and misjudgments drivers to improve the traffic safety will play an important role.Obviously, this kind of product research and development has great realize meaning and broad application prospects.1.3 Ultrasonic ranging in automotive applications introduced

Ultrasonic back-draft rangefinder(known as electron optics)automotive anti-collision reversing device, can safe adjunct to sound or more intuitive digital form the dynamic display of around obstacles.Its earlier products is to use buzzer alarm, hum more anxious, and says vehicles from obstructions closer.Subsequent product can display the car from the body after the obstacles distance.Most of its products detection range in 0.4 ~ 1.5 m, some product can achieve 0.35 ~ 2.5 m, and have distance display, sound alarm, area-warning and azimuth instructions, some products also has the boot self-checking function.Still appeared on the market at present with voice alarm function of products.These products are the main problem is big, alarm measuring blind area lags behind, without considering the automobile braking inertial factors and make drivers brake lag, the anti-interference ability is not strong, misstatement or more.The automotive anti-collision radar is able to realize impact-proof alarm functions, basically have ultrasonic this intangible ruler, it recently obstacles distance measurement, and told to the owner.Actually ultrasonic range-finding principle simple: it emit ultrasonic echo, and receive reflected by microcontroller counter obtain both lag using formula S = t, Ct / 2 calculating distances, including S for cars and obstacles, C for the distance between the sound wave propagation in the medium speed.This paper introduces the ultrasonic ranging system only have 2 ultrasonic transducer(known as probe)respectively, decorate in cars left and right after after 2 position.Capable of detecting forward and reverse direction obstacle distance, the rearview mirror built-in display element display distance and direction, issued must be sound, plays the role of hints and alert.System USES a STC89C52 SCM two way ultrasonic signal cyclicly acquisition.Ultrasonic refers to the 20HHZ wave frequency is over.In order to use the ultrasonic detection means, must generate as ultrasonic wave and receiving damnation.Complete the functions of the device is called the

中原工学院毕业设计（论文）译文

ultrasonic sensor, habit, ultrasonic transducer or ultrasonic probe.Ultrasonic sensors have both transmitters and receivers, but a ultrasonic sensors can also has the sending and receiving the sound waves of the dual role.Ultrasonic sensors is using the principle of piezoelectric effect and ultrasonic energy conversion, be in namely emit ultrasonic, energy conversion, launch ultrasonic, And in the stockades, received echo ultrasonic vibration into electrical signal.Ultrasonic ranging principle generally USES the time method for the crossing.First measured ultrasonic from the launch to meet obstacles returns experience of time, again multiply ultrasonic speed of get twice the distance between the sound source and obstacles.Measuring distance a variety of ways, short can use ruler, long-range laser displacement etc, are suitable for high accuracy of ultrasonic ranging in long distance measurement.Because of ultrasound in standard air of propagation speed 331.45 meters per second, by single-chip microcomputer is responsible for timing, SCM use 12.0 M crystals, so the system of measurement precision theory can achieve mm level.Because of ultrasonic directivity strong, energy consumption is slow, in a medium transmission distance, thus ultrasonic can be used for distance measurement.Using ultrasonic detection distance, the design is more convenient, computing procese also relatively simple, and the measurement precision can also meet the requirements.Ultrasonic generator can be divided into two kinds: one kind is to use electrical means producing ultrasonic, one kind is with mechanical approach to producing ultrasonic.This design belongs to nearly distance measurement, can use commonly used the piezoelectric ultrasonic transducer to achieve trigger unit.Using ultrasonic ranging work, can according to measuring launch reflection wave wave and the time interval between the measured distance, so as to achieve the effect.It mainly have three ranging methods:

(1)phase assay, phase assays high precision, but detection though limited range，(2)sound amplitude assay, acoustic amplitude assay vulnerable reflection wave influence;

(3)ferrying more time assay, crossing the time assay way of working is simple, intuitive, in hardware control and software design are very easy to implement.Its principle is: from the launch emit ultrasonic detection sensor, the gas medium spread to receive sensor of time, this time is crossing the more time.This design is the use of ultrasonic ranging the crossing the time assay.In the mobile vehicles of the application 15

中原工学院毕业设计（论文）译文

of ultrasonic sensor is the use of ultrasound in air of directional spread and solid reflective characteristics(p-wave)and by receiving their launch ultrasonic reflecting signal, according to the ultrasonic issued and echo receiving the Windows and propagation speed, calculate transmission distance, thus obtains the obstacles to vehicle distance.中原工学院毕业设计（论文）译文

2.A principle of ultrasonic distance measurement

2.1 the principle of piezoelectric ultrasonic generator

Piezoelectric ultrasonic generator is the use of piezoelectric crystal resonators to work.Ultrasonic generator, the internal structure as shown, it has two piezoelectric chip and a resonance plate.When it’s two plus pulse signal, the frequency equal to the intrinsic piezoelectric oscillation frequency chip, the chip will happen piezoelectric resonance, and promote the development of plate vibration resonance, ultrasound is generated.Conversely, if the two are not inter-electrode voltage, when the board received ultrasonic resonance, it will be for vibration suppression, then it becomes the ultrasonic receiver.The traditional way to determine the moment of the echo’s arrival is based on thresholding the received signal with a fixed reference.The threshold is chosen well above the noise level, whereas the moment of arrival of an echo is defined as the first moment the echo signal surpasses that threshold.The intensity of an echo reflecting from an object strongly depends on the object’s nature, size and distance from the sensor.Further, the time interval from the echo’s starting point to the moment when it surpasses the threshold changes with the different intensities arriving exactly at the same tome will surpass the threshold at different moments.The stronger one will surpass the threshold earlier than the weaker, so it will be considered as belonging to a nearer object.2.2 The principle of ultrasonic distance measurement Ultrasonic transmitter in a direction to launch ultrasound, in the moment to launch the beginning of time at the same time, the spread of ultrasound in the air, obstracles on his way to return immediately, the ultrasonic reflected wave wave received by the reveiver immediately stop the clock.Ultrasonic in the air as the propagation velocity of 340m/s, according to the timer records the time t, we can calculate the distance between the launch distance barrier(s), that is:s=340t/2

中原工学院毕业设计（论文）译文

3.Ultrasonic Ranging System for the Second Circuit Design

System is characterized by single-chip microcomputer to control the use of ultrasonic transmitter and ultrasonic receiver since the launch from time to time, single-chip selection of 8751,economic-to –use, and the chip has 4K of ROM, to facilitate programming.Circuit schematic diagram shown in Figure 1.Figure 1 circuit principle diagram

中原工学院毕业设计（论文）译文

3.1 40 kHz ultrasonic pulse generated with the launch

Ranging system using the ultrasonic sensor of piezoelectric sensors UCM40, its operating voltage of the pulse signal is 40kHz, which by the single-chip implementation of the following procedures to generate.Puzel:mov 14h,# 12h;ultrasonic firing continued 200ms here:cpl pl.0;output 40 kHz square wave

nop;

nop;nop;djnz 14h, here;ret Ranging in front of single-chip termination circuit P1.0 input port, single chip implementation of the above procedure, the P1.0 port in a 40kHz pulze output signal, after amplification transistor T, the drive to launch the first ultrasonic UCM40T, issued 40kHz ultrasonic pulse, and the continued launch of 200ms.Ranging the right and the left side of the circuit, respectively, then input port P1.1 and P1.2, the working principle and circuit in front of the same location.3.2 Reception and processing of ultrasonic

Used to receive the first launch of the first pair UCM40R, the ultrasonic pulse modulation signal into an alternating voltage, the op-amp amplification IC1A and after polarization IC1B to IC2.IC2 is locked loop with audio decoder chip LM567, internal voltage-controlled oscillator center frequency of f0=1/1.1R8C3, capacitor C4 determine their target bandwidth.R8-conditioning in the launch of the carrier frequency on the LM567 input signal is greater than 25Mv, the output from the high jump 8 feet into a low-level, as interrupt request signals to the single-chip processing.Ranging in front of single-chip termination circuit port INT0 interrupt the highest priority, right or left location of the output circuit with output gete IC3A access INT1 port single-chip, while single-chip P1.3 and P1.4 received input IC3A, interrupted by the process to identify the source code is as follows: receivel:

push psw

push ace

中原工学院毕业设计（论文）译文

cir ex1: related external interrupt 1

jnb p1.1, right;P1.1 pin to 0, ranging from right to interrupt service rountine circuit

jnb p1.2, left;P1.2 pin to 0, to the left ranging circuit

interrupt service routine return:SETB EX1;open external interrupt 1

pop

acc pop

psw reti right:…;right location entrance circuit interrupt service rountine

Ajmp Return left:…;left Ranging entrance circuit interrupt service rountine

Ajmp Return

3.3 The calculation of ultrasonic propagation time

When you start firing at the same time start the single-chip circuitry within the timer T0, the use of timer counting function records the time and the launch of ultrasonic reflected wave received time when you receive the ultrasonic reflected wave, the receiver circuit outputs a negative jump in the end of INT0 or INT1 interrupt request generates a signal, single-chip microcomputer in response to external interrupt request, the implementation of the external interrupt service subroutine, read the time difference, calculating the distance.Some of its source is as follows: RECEIVE0: PUSH PSW PUSH ACC CLR EX0;related external interrupt 0 MOV R7, TH0;read the time value MOV R6, TL0 CLR C MOV A, R6 SUBB A,#0BBH;calculate the tome difference MOV 31H, A;storage results MOV A, R7 SUBB A,#3CH

中原工学院毕业设计（论文）译文

MOV 30H,A SETB EX0;open external interrupt 0 POP ACC POP PAW RETI For a flat target, a distance measurement consists of two phases: a coarse measurement and, a fine measurement: Step 1: Transmission of one pulse train to produce a simple ultrasonic

Wave.Step 2: Changing the gain of both echo amplifiers according to equation，until the echo is detected.Step 3:detection of te amplitudes anf zero-crossing times of both echoes.Step 4:setting the gains of both echo amplifiers to normalize the output at, say 3 volts.Setting the period of the next pulses according to the: period of echoes.Setting the time window according to the data of step 2.Step 5:sending two pulse trains to produce an interfered wave.Testing the zero-crossing in the echo,detemine to otherwise calculate to by interpolation using the amplitudes near the trough.Derive t sub ml and t sub m2.Step6: Calculation of the distance y using equation.中原工学院毕业设计（论文）译文

4.The ultrasonic ranging system software design

Software is divided into two parts, the main program and interrupt service routine.Completion of the work of the main program is initialized, each sequence of ultrasonic transmitting and receiving control.Tnterrupt service routines from time to complete three of the rotation direction of ultrasonic launch, the main external interrupt service subroutine to resd the value of completion time, distance calculation, the results of the output and so on.中原工学院毕业设计（论文）译文

5.Conclusions

Required measuring range of 30cm~200cm objects inside the plane to do a number of measurements found that the maximum error is 0.5cm, and good reproducibility.Single-chip design can be seen on the ultrasonic ranging system has a hardware structure is simple, reliable, small features such as measurement error.Therefore, it can be used not only for mobile robot can be used in other detection systems.Thoughts: As for why the receiver do not have the transistor amplifier circuit, because the magnification well, integrated amplifier, but also with automatic gain control level, magnification to 76dB, the center frequency is 38k to 40k, is exactly resonant ultrasonic sensors frequency.中原工学院毕业设计（论文）译文

REFERENCES 1.Fox,J.D.,Khuri-Yakub, B.T.and Kino, G.S., ‖High Frequency Acoustic Wave Measurement in Air‖, in Proceedings of IEEE 1983 Ultrasonic Symposium, October 31-2 November, 1983, Atlanta, GA, pp.581-4.2.Martin Abreu,J.M.,Ceres,R.and Freire, T.,‖Ultrasonic Ranging: Envelope Analysis Gives Improved Accuracy‖, Sensor Review, Vol.12No.1,1992, pp.17-21.3.Parrilla， M., Anaya,J.J and Fritsch C.,‖Digital Signal Processing Techniques for High Accuracy Ultrasonic Range Measurement:,IEEE Transactions: Instrumentation and Measurement.Vol.40 No.4, August 1991,pp.750-63.4.Canali, C., Cicco, G.D., Mortem, B., Prudenziati, M., and Taron, A., ―A Temperature Compensated Ultrasonic Sensor Operating in Air for Distance and Proxinmity Measurement‖, IEEE Trasaction on Industry Electronics, Vol, IE-29 No.4,1982, pp.336-41.5.Martin, J.M., Ceres, R., Calderon, L and Freire, T., ‖Ultrasonic Ranging Gets Themal Correction‖, Sensor Review, Vol, 9 No.3, 1989,pp.153-5.24

第五篇：外文翻译

Low Voltage Flyback DC-DC Converter For

Power Supply Applications Hangzhou Liu1, John Elmes2, Kejiu Zhang1, Thomas X.Wu1, Issa Batarseh1

Department of Electrical Engineering and Computer Science, University of Central Florida, Orlando, FL 32816, USA Advanced Power Electronics Corporation, Orlando, FL 32826, USA Abstract ：In this paper, we design a low voltage DC-DC converter with a flyback transformer.The converter will be used as a biased power supply to drive IGBTs.The flyback transformer using planar EI-core is designed and simulated using ANSYS PExprt software.Besides, anLT3574 IC chip from Linear Technology has been chosen for converter control.Finally, the converter modeling and simulation are presented and PCB layout is designed.Keywords：Flyback, anLT3574IC, PCB

I.INTRODUCTION The goal of this project is to develop and build a prototype of a high-efficiency, high-temperature isolated DC-DC converter to be used as a biased power supply for driving a complementary IGBT pair.It is important that the converter can deliver the required power at an ambient temperature of up to 100℃;therefore it has to be efficient so that its components do not exceed their maximum temperature ratings.The final converter will be completely sealed and potted in a metal case.The input voltage range for this converter is from 9V to 36V.The output sides have two terminals, one is﹢16V and the other one is﹣6V.In order to get the desired performance, anLT3574 IC chip from Linear Technology is used.The key to this design is the flyback transformer.The transformer using planar EI-core is designed and simulated using ANSYS PExprt software.Finally, the PCB layout of the converter will be presented.II.KEY DESIGN OUTLINE For this flyback topology, the output voltage can be determined by both the transformer turns ratio and the flyback loop resistor pairs.Therefore, at the initial design stage, we can choose a convenient turn’s ratio for the transformer, and modify it later on if necessary to make sure the output performance is desirable and the transformer will not saturate [1].The relationship between transformers turns ratio and duty cycle can be found as

Where n is the transformer turns ratio, D is the duty cycle, VO` is the sum of the output voltage plus the rectifier drop voltage, VIN is the input voltage of the transformer.The value of feedback resistor can be calculated as

Where RREF is the reference resistor, whose value is typically 6.04kΩ;α is a constant of 0.986;VBG is the internal band gap reference voltage, 1.23V;and VTC is normally 0.55V [1].With a specific IC chosen, the converter circuit can be designed based on a demo circuit and some parameters may need to be modified if necessary to optimize the performance.Furthermore, in LT Spice, a large number of simulations need to be done with different conditions such as load resistor values and input voltage levels.It is important to make sure that the output voltage can be regulated well with all these different conditions.The most critical part of the design is the flyback transformer.With high switching frequency, the AC resistance can only be estimated based on some traditional methods such as Dowell’s curve rule [2].In order to get more accurate values of AC resistance values;we propose to use finite element electromagnetic software ANSYS PExprt to do the design [3].At the initial design stage, key parameters such as the worst-case input voltage, frequency, material, inductance values will be decided.After that, these data will be imported to the software, from which an optimized solution will be generated.III.CONVERTER SIMULATION RESULTS We choose LT3574 chip in this design.From the simulation results in Figure 1 and Table 1, it clearly shows that the output voltages which are﹢16V and-6V respectively can be regulated pretty well with the input voltage range from 9V to 36V.The voltage tolerance ranges are from ﹢15V to ﹢19V and-12V toDC converter for low voltage power supply application has been designed.The modeling and simulation results are presented.Based on the design specifications, a suitable IC from Linear Technology is chosen.A large amount of circuit simulations with different conditions such as load resistor values and input voltage levels are presented to get the desirable output voltage and current performance.The transformer has been designed including electrical, mechanical and thermal properties.With all the specific components decided, the PCB layout of the converter has been designed as well.REFERENCE

[1] Linear Technology Application Notes , Datasheet of Isolated Flyback Converter Without an Opto-Coupler, http://cds.linear.com/docs /Datasheet/3574f.pdf.[2] P.L.Dowell, “Effect of eddy currents in transformer windings” Proceedings of the IEE, NO.8 PP.1387-1394, Aug 1966.[3] S.Xiao, “Planar Magnetics Design for Low-Voltage DC-DC Converters” MS, 2004.[4] ANSYS Application Notes, PEmag Getting Started: A Transformer Design Example, http://www.xiexiebang.com/download/ EDA/Maxwell9/planarGS0601.pdf.[5] K.Zhang;T.X.Wu;H.Hu;Z.Qian;F.Chen.;K.Rustom;N.Kutkut;J.Shen;I.Batarseh;“Analysis and design of distributed transformers for solar power conversion” 2011 IEEE Applied Power Electronics Conference and Exposition(APEC), v l., no., pp.1692-1697, 6-11 March 2011.[6] Zhang.;T.X.Wu.;N.Kutkut;J.Shen;D.Woodburn;L.Chow;W.Wu;H.Mustain;I.Batarseh;,“Modeling and design optimization of planar power transformer for aerospace applic ation,” Proceedings of the IEEE 2009 National, Aerospace & Electronics Conference(NAECON), vol., no., pp.116-120, 21-23 July 2009.[7] Ferroxcube Application Notes, Design of Planar Power Transformer,