基于lc玻璃纤维生产线控制系统的设计.docx

《基于lc玻璃纤维生产线控制系统的设计.docx》由会员分享，可在线阅读，更多相关《基于lc玻璃纤维生产线控制系统的设计.docx（24页珍藏版）》请在沃文网上搜索。

1、英文原文6中文翻译18课题来源由20世纪30年代开始，坩埚连续拉制工艺由美国人发明，不断的发展到现在，形成了现代化工业生产。由于科技的不断提高和工业应用不断提高，对生产出来的玻璃纤维的性能提出了更高的要求，例如有些的工作的环境温度极高，这是需要玻璃纤维的耐热性要提高，还有有些工作需要拉伸玻璃纤维，这时对玻璃纤维的力学性能有一定的要求，在1960以后出来很多特殊的纤维，如有些玻璃纤维能耐高温，有些玻璃纤维强度高，有些玻璃纤维模量高等。现在玻璃纤维发展出现了一支在电绝缘玻璃纤维系列产品的新秀，并在半导体行业迅速得到广泛使用。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）

2、1 本课题在对生产线控制系统的研究的基础上，对控制系统硬件和软件进行设计并组织实施，帮助企业解决生产线存在的问题，从而提高产品的质量和成品率，以满足市场发展对产品的要求。2中国玻璃纤维行业近几年的快速发展，动力来自国内和国外两个市场的拉动。国际市场的扩大，既有总需求增长的因素，也有来自国际企业前期因利润率较低退出行业后，给国内企业在国际市场留下的发展空间；而国内市场的增长，则是来自下游消费行业的快速发展。中国玻璃纤维经过了50多年的发展，已经颇具规模。长远来看，中东、亚太基础设施的加强和改造，对玻纤需求增加了很大的数量，随着全球在玻纤改性塑料、运动器材、航空航天等方面对玻纤的需求不断增长，玻纤

3、行业前景仍然乐观。另外玻纤的应用领域又扩展到风电市场，这可能是玻纤未来发展的一个亮点。能源危机促使各国寻求新能源，风能成为如今关注的一个焦点，中国在风电领域也开始加大力度投资。到2020年，国内在风力发电领域将投资3500亿元，其中，20%（即700亿元）左右的领域需要使用玻纤（如风机叶片等方面）。这对中国玻纤企业来说是一个很大的市场。研究内容 了解玻璃纤维生产线的工作原理，国内外的研究发展现状； 完成玻璃纤维生产线的接线图； 完成I/O模块； 熟练掌握S7-200的使用，在使用编写梯形图； 完成设计说明书的撰写，并翻译外文资料1篇。拟采取的研究方法、技术路线、实验方案及可行性分析了解完玻璃纤

4、维生产线所有设备之后，不难发现其工作的原理和各个设备之间运行的先后顺序。于是可以先确定各个设备起到的作用，在整个玻璃纤维生产线中起到的作用。比如说拉丝机是将原料熔化的玻璃液进行拉伸成玻璃纤维，捻线机是将成型的玻璃纤维进行捻线成线。控制玻璃纤维生产线的所有设备可以由PLC进行控制。因为它具备逻辑控制、定时、计数等功能，完全可以控制玻璃纤维生产线中各个设备的先后启动顺序。控制启动时间。根据三年多所学的专业知识及通过参阅电器控制与PLC应用、PLC控制系统工作方式的分析和研究及相关图册资料，综合考虑玻璃纤维生产线的制造成本和周期，本人拟采用的总体方案是：事先在PLC中输入各种相关参数，然后工作人员根

5、据生产要求进行PLC控制生产。 该设计方案经慎重考虑，多次试验，多次论证，应该是切实可行的。研究计划及预期成果研究计划：2013年11月12日-2013年11月27日：按照任务书要求查阅论文相关参考资料，填写毕业设计开题报告书。2013年11月28日-2013年2月10日：填写毕业实习报告,学习并翻译一篇与毕业设计相关的英文材料。2014年2月15日-2014年2月27日：完成毕业设计开题报告。2014年3月1日-2014年3月10日：玻璃纤维生产线接线图。2014年3月11日-2014年3月 26 日：I/O分配表、梯形图。2014年4月 1 日-2014年5月10日：毕业论文撰写。2014

6、年5月 10日-2014年5月20日：毕业论文修改工作。成果：通过PLC控制的玻璃纤维生产线可以大大提高生产的可行性和可靠性，并且降低了生产成本。特色或创新之处（1）能解决生产效率低、劳动强度大的问题，还大大提高了效率。已具备的条件和尚需解决的问题已具备的条件：设计过程中所需要的各种软硬件资源和相关产品实物照片。尚需解决的问题：相关文献资料的缺乏，对一些程序部分的具体编写指导，以及在实际中运行的测试。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 系主任（签名）： 年 月 日系意见主管领导签名： 年 月 日 英文原文Visualization of PLC Progr

7、ams using XMLP. 0. Box 3049, D-67653 Kaiserslautem, Germany Abstract - Due to the growing complexity of PLC programs there is an increasing interest in the application of formal methods in this area. Formal methods allow rigid proving of system properties in verification and validation. One way to a

8、pply formal methods is to utilize a formal design approach in PLC programming. However, for existing software that has to be optimized, changed, or ported to new systems .There is the need for an approach that can start from a given PLC program. Therefore, formalization of PLC programs is a topic of

9、 current research. The paper outlines a re-engineering approach based on the formalization of PLC programs. The transformation into a vendor independent format and the visualization of the structure of PLC programs is identified as an important intermediate step in this process. It is shown how XML

10、and corresponding technologies can be used for the formalization and visualization of an existing PLC program. I. INTRODUCTIONProgrammable Logic Controllers (PLCs) are a special type of computers that are used in industrial and safety critical applications. The purpose of a PLC is to control a parti

11、cular process, or a collection of processes, by producing electrical control signals in response to electrical process- related inputs signals. The systems controlled by PLCs vary tremendously, with applications in manufacturing, chemical process control, machining, transportation, power distributio

12、n, and many other fields. Automation applications can range in complexity from a simple panel to operate the lights and motorized window shades in a conference room to completely automated manufacturing lines.With the widening of their application horizon， PLC programs are being subject to increased

13、 complexity and high quality demands especially for safety-critical applications. The growing complexity of the applications within the compliance of limited development time as well as the reusability of existing software or PLC modules requires a formal approach to be developed I. Ensuring the hig

14、h quality demands requires verification and validation procedures as well as analysis and simulation of existing systems to be carried out 2. One of the important fields for the formalization of PLC programs that have been growing up in recent time is Reverse-engineering 3. Reverse Engineering is a

15、process of evaluating something to understand how it works in order to duplicate or enhance it. While the reuse of PLC codes is being established as a tool for combating the complexity of PLC programs, Reverse Engineering is supposed to receive increased importance in the coming years especially if

16、exiting hardware has to be replaced by new hardware with different programming environmentsVisualization of existing PLC programs is an important intermediate step of Reverse Engineering. The paper provides an approach towards the visualization of PLC programs using XML which is an important approac

17、h for the orientation and better understanding for engineers working with PLC programs. The paper is structured as follows. First, a short introduction to PLCs and the corresponding programming techniques according to the IEC 61131-3 standard is given. In Section an approach for Re-engineering based

18、 on formalization of PLC programs is introduced. The transformation of the PLC code into a vendor independent format is identified as an important first step in this process. XML and corresponding technologies such as XSL and XSLT that can be used in this transformation are presented in Section IV.

19、Section V presents the application of XML for the visualization of PLC programs and illustrates the approach with an example. The final Section summarizes the results and gives an outlook on future work in this ongoing project. PLC AND IEC 61131Since its inception in the early 70s the PLC received i

20、ncreasing attention due to its success in fulfilling the objective of replacing hard-wired control equipments at machines. Eventually it grew up as a distinct field of application, research and development, mainly for Control Engineering. IEC 61 131 is the first real endeavour to standardize PLC pro

21、gramming languages for industrial automation. In I993 the International Electrotechnical Commission 4 published the IEC 61131 Intemational Standard for Programmable Controllers. Before the standardization PLC programming languages were being developed as proprietary programming languages usable to P

22、LCs of a special vendor. But in order to enhance compatibility, openness and interoperability among different products as well as to promote the development of tools and methodologies with respect to a fixed set of notations the IEC 61131 standard evolved. The third part of this standard defines a s

23、uit of five programming languages:Instruction List (IL) is a low-level textual language with a structure similar to assembler. Originated in Europe IL is considered to be the PLC language in which all other IEC61 131-3 languages can be translated.Ladder Diagram (LO) is a graphical language that has

24、its roots in the USA. LDs conform to a programming style borrowed from electronic and electrical circuits for implementing control logics.Structured Text (STJ is a very powerful high-level language. ST borrows its syntax from Pascal, augmenting it with some features from Ada. ST contains all the ess

25、ential elements of a modem programming language.Function Block Diagram (FBD) is a graphical language and it is very common to the process industry. In this language controllers are modelled as signal and data flows through function blocks. FBD transforms textual programming into connecting function

26、blocks and thus improves modularity and software reuse.Sequential Function Chart (SFC) is a graphical language. SFC elements are defined for structuring the organization of programmable controller programs.One problem with IEC 61 131-3 is that there is no standardized format for the project informat

27、ion in a PLC programming tool. At the moment there are only vendor specific formats. This is also one reason for the restriction of formalization approaches to single programs or algorithms. However, recently the PLC users organization PLCopen (see http:/www.plcopen.org) started a Technical Committe

28、e to define an XML based format for projects according to IEC 61131-3. This new format will ease the access of formalization tools to all relevant information of a PLC project. RE-ENGINEERING APPROACHThe presented approach towards re-engineering (cf. Fig.1) is based upon the conception that XML can

29、be used as a medium in which PLC codes will be transformed.This transformation offers the advantage of obtaining avendor independent specification code. (Even if the PLCopen succeeds in defining a standardized format for PLC applications, there will remain a lot of existing programs that do not conf

30、orm to this standard.) Based on this code a step-wise transformation to a formal model (automata) is planned. This model can then be used for analysis, simulation, formal verification and validation, and finally for the re-implementation of the optimized algorithm on the same or another PLC.Since re

31、-engineering of complete programs will, in most cases, be only a semi-automatic process, intermediate visualization of the code is an important point. At different stages of the process different aspects of the code and/or formal model have to be visualized in a way that a designer can guide the fur

32、ther work. XML with its powerful visualization and transformation tools is an ideal tool for solving this task.IV. XML AS A TOOL FOR VISUALIZATIONXML (extensible Markup Language) is a simple and flexible meta-language, i.e， a language for describing other languages. Tailored by the World Wide Web Co

33、nsortium (W3C) as a dialect of SGML S, XML removes two constraints which were holding back Web developments 6. The dependence on a single, inflexible document type (HTML) which was being much abused for tasks it was never designed for on one side; and the complexity of full SGML, whose syntax allows

34、 many powerful but hard-to-program options on the other side.While HTML describes how data should be presented, XML describes the data itself. A number of industries and scientific disciplines-medical records and newspaper publishing among them-are already using XML to exchange information across pl

35、atforms and applications. XML can be tailored to describe virtually any kind of information in a form that the recipient of the information can use in a variety of ways. It is specifically designed to support information exchange between systems that use fundamentally different forms of data represe

36、ntation, as for example between CAD and scheduling applications.Using XML with its powerful parsers and inherent robustness in terms of syntactic and semantic grammar is more advantageous than the conventional method of using a lexical analyzer and a validating parser (cf. Fig. 2, 7).The conventiona

37、l method of analysis of program code requires a scanner (lexical analyser) which generates a set of terminal symbols (tokens) followed by a parser thatchecks the grammatical structure of the code and generates an object net. In the object net the internal structure of the program is represented by i

38、dentified objects and the relations between them. Both the scanner and the parser to be used in this method are document oriented which implies that analysis of different types of documents requires rewriting the generated code for the scanner and the parser. An example of an application of this met

39、hod can be found in 8.The most promising aspect of using XML instead is that XML and its complementary applications for transformations are standardized so as to provide maximum flexibility to its user.The XML based method is advantageous, since the lexical specification is an invariant component of

40、 XML; therefore the well-formedness is independent from the respective individual application.Hence, an XML-Parser also can transfer well-shaped XML documents in an abstract representation called Document Object Model (DOM) without using a grammar. DOM is an application programming interface (APII)

41、for valid HTML and well-formed XML documents. It defines the logical structure of documents and the way a document is accessed and manipulated. In the DOM specification, the term document is used in a broad sense increasingly. XML is used as a way of representing many different kind of information t

42、hat may be stored in diverse systems, and much of this would traditionally be seen as data rather than as documents. Nevertheless, XML presents this data as documents, and the DOM can be used to manage this data5.XSLT, the transformation language for XML is capable of transforming XML not only to an

43、other XML or HTML but to many other user-friendly formats. Before the advent of XSLT, the transformation of XML to any other format was only possible through custom applications developed in a procedural language such as C+, Visual Basic or, Java. This procedure lacked the generality with respect to

44、 the structural variation of XML documents. Capitalizing on the concept that the custom applications for the transformations are all very similar, XSLT evolved as a high-level declarative language 9. XSLT functions in two steps. In the first step, it performs a structural transformation so as to con

45、vert the XML into a structure that reflects the desired output. The second stage is formatting the new structure into the required format, such as HTML or PDF (cf. Fig. 3 ). The most important advantage of this transformation is that it allows a simple and easily-conceivable representation of the do

46、cument or data structure embedded inside the well-structured but hard-to-understand XML to be produced. When HTML is chosen as the format of the transformed produce it is possible to use the extensive ability of HTML to produce an easily-conceivable and attractive visualization of a program.Every XM

47、L document has its own syntax and vocabulary. Therefore, in addition to being well-formed, the XML document needs to conform to a set of rules. According to W3C recommendations this set of rules has to be defined either through a Document Type Definition (DTD) or an XML Schema. The rules defined in

48、a DTD or an XML Schema state the hierarchical and structural constraints of the XML document. The DTD is for defining the document grammars; more recently a number of alternative languages have been proposed. The W3C XML Schema language replicates the essential functionality of DTDs, and adds a number of features: the use of XML instance syntax rather