动机可编程控制器(PLC)中英文翻译张.doc

1、河南科技学院2009届本科毕业论文（设计）相关中英文资料资料题目：动机可编程控制器（PLC）学生姓名： 所在院系： 机电学院所学专业： 机电技术教育英文资料： Motivation Programmable Logic Controllers (PLC), a computing device invented by Richard E. Morley in 1968, have been widely used in industry including manufacturing systems, transportation systems, chemical process facil

2、ities, and many others. At that time, the PLC replaced the hardwired logic with soft-wired logic or so-called relay ladder logic (RLL), a programming language visually resembling the hardwired logic, and reduced thereby the configuration time from 6 months down to 6 days Moody and Morley, 1999. Alth

3、ough PC based control has started to come into place, PLC based control will remain the technique to which the majority of industrial applications will adhere due to its higher performance, lower price, and superior reliability in harsh environments. Moreover, according to a study on the PLC market

4、of Frost and Sullivan 1995, an increase of the annual sales volume to 15 million PLCs per year with the hardware value of more than 8 billion US dollars has been predicted, though the prices of computing hardware is steadily dropping. The inventor of the PLC, Richard E Morley, fairly considers the P

5、LC market as a 5-billion industry at the present time. Though PLCs are widely used in industrial practice, the programming of PLC based control systems is still very much relying on trial-and-error. Alike software engineering, PLC software design is facing the software dilemma or crisis in a similar

6、 way. Morley himself emphasized this aspect most forcefully by indicating Moody and Morley, 1999, P110: If houses were built like software projects, a single woodpecker could destroy civilization.” Particularly, practical problems in PLC programming are to eliminate software bugs and to reduce the m

7、aintenance costs of old ladder logic programs. Though the hardware costs of PLCs are dropping continuously, reducing the scan time of the ladder logic is still an issue in industry so that low-cost PLCs can be used. In general, the productivity in generating PLC is far behind compared to other domai

8、ns, for instance, VLSI design, where efficient computer aided design tools are in practice. Existent software engineering methodologies are not necessarily applicable to the PLC based software design because PLC-programming requires a simultaneous consideration of hardware and software. The software

9、 design becomes, thereby, more and more the major cost driver. In many industrial design projects, more than SO0/a of the manpower allocated for the control system design and installation is scheduled for testing and debugging PLC programs Rockwell, 1999. In addition, current PLC based control syste

10、ms are not properly designed to support the growing demand for flexibility and reconfigurability of manufacturing systems. A further problem, impelling the need for a systematic design methodology, is the increasing software complexity in large-scale projects. 1.2 Objective and Significance of the T

11、hesis The objective of this thesis is to develop a systematic software design methodology for PLC operated automation systems. The design methodology involves high-level description based on state transition models that treat automation control systems as discrete event systems, a stepwise design pr

12、ocess, and set of design rules providing guidance and measurements to achieve a successful design. The tangible outcome of this research is to find a way to reduce the uncertainty in managing the control software development process, that is, reducing programming and debugging time and their variati

13、on, increasing flexibility of the automation systems, and enabling software reusability through modularity. The goal is to overcome shortcomings of current programming strategies that are based on the experience of the individual software developer. A systematic approach to designing PLC software ca

14、n overcome deficiencies in the traditional way of programming manufacturing control systems, and can have wide ramifications in several industrial applications. Automation control systems are modeled by formal languages or, equivalently, by state machines. Formal representations provide a high-level

15、 description of the behavior of the system to be controlled. State machines can be analytically evaluated as to whether or not they meet the desired goals. Secondly, a state machine description provides a structured representation to convey the logical requirements and constraints such as detailed s

16、afety rules. Thirdly, well-defined control systems design outcomes are conducive to automatic code generation- An ability to produce control software executable on commercial distinct logic controllers can reduce programming lead-time and labor cost. In particular, the thesis is relevant with respec

17、t to the following aspects. Customer-Driven Manufacturing In modern manufacturing, systems are characterized by product and process innovation, become customer-driven and thus have to respond quickly to changing system requirements. A major challenge is therefore to provide enabling technologies tha

18、t can economically reconfigure automation control systems in response to changing needs and new opportunities. Design and operational knowledge can be reused in real-time, therefore, giving a significant competitive edge in industrial practice. Higher Degree of Design Automation and Software Quality

19、 Studies have shown that programming methodologies in automation systems have not been able to match rapid increase in use of computing resources. For instance, the programming of PLCs still relies on a conventional programming style with ladder logic diagrams. As a result, the delays and resources

20、in programming are a major stumbling stone for the progress of manufacturing industry. Testing and debugging may consume over 50% of the manpower allocated for the PLC program design. Standards IEC 60848, 1999; IEC-61131-3, 1993; IEC 61499, 1998; ISO 15745-1, 1999 have been formed to fix and dissemi

21、nate state-of-the-art design methods, but they normally cannot participate in advancing the knowledge of efficient program and system design. A systematic approach will increase the level of design automation through reusing existing software components, and will provide methods to make large-scale

22、system design manageable. Likewise, it will improve software quality and reliability and will be relevant to systems high security standards, especially those having hazardous impact on the environment such as airport control, and public railroads. System Complexity The software industry is regarded

23、 as a performance destructor and complexity generator. Steadily shrinking hardware prices spoils the need for software performance in terms of code optimization and efficiency. The result is that massive and less efficient software code on one hand outpaces the gains in hardware performance on the o

24、ther hand. Secondly, software proliferates into complexity of unmanageable dimensions; software redesign and maintenance-essential in modern automation systems-becomes nearly impossible. Particularly, PLC programs have evolved from a couple lines of code 25 years ago to thousands of lines of code wi

25、th a similar number of 1/O points. Increased safety, for instance new policies on fire protection, and the flexibility of modern automation systems add complexity to the program design process. Consequently, the life-cycle cost of software is a permanently growing fraction of the total cost. 80-90%

26、of these costs are going into software maintenance, debugging, adaptation and expansion to meet changing needs Simmons et al., 1998.Design Theory Development Today, the primary focus of most design research is based on mechanical or electrical products. One of the by-products of this proposed resear

27、ch is to enhance our fundamental understanding of design theory and methodology by extending it to the field of engineering systems design. A system design theory for large-scale and complex system is not yet fully developed. Particularly, the question of how to simplify a complicated or complex des

28、ign task has not been tackled in a scientific way. Furthermore, building a bridge between design theory and the latest epistemological outcomes of formal representations in computer sciences and operations research, such as discrete event system modeling, can advance future development in engineerin

29、g design. Application in Logical Hardware Design From a logical perspective, PLC software design is similar to the hardware design of integrated circuits. Modern VLSI designs are extremely complex with several million parts and a product development time of 3 years Whitney, 1996. The design process

30、is normally separated into a component design and a system design stage. At component design stage, single functions are designed and verified. At system design stage, components are aggregated and the whole system behavior and functionality is tested through simulation. In general, a complete verif

31、ication is impossible. Hence, a systematic approach as exemplified for the PLC program design may impact the logical hardware design. 1.3 Structure of the Thesis Figure 1.1 illustrates the outline of the following thesis. Chapter 2 clarifies the major challenges and research issues, and discourses t

32、he relevant background and terminology. It will be argued that a systematic design of PLC software can contribute to higher flexibility and reconfigurability of manufacturing systems. The important issue of how to deal with complexity in engineering design with respect to designing and operating a s

33、ystem will be debated. The research approach applied in this thesis is introduced starting from a discussion of design theory and methodology and what can be learnt from that field. Chapter 3 covers the state-of-the-art of control technology and the current practice in designing and programming PLC

34、software. The influences of electrical and software engineering are revealed as well as the potentially applicable methods from computer science are discussed. Pros and cons are evaluated and will lead to the conclusion that a new methodology is required that suffices the increasing complexity of PL

35、C software design. Chapter 4 represents the main body of the thesis and captures the essential features of the design methodology. Though design theory is regarded as being in a pre- scientific stage it has advanced in mechanical, software and system engineering with respect to a number of proposed

36、design models and their evaluation throughout real-world examples. Based on a literature review in Chapter 2 and 3 potential applicable design concepts and approaches are selected and applied to context of PLC software design. Axiomatic design is chosen as underlying design concept since it provides

37、 guidance for the designer without restriction to a particular design context. To advance the design concept to PLC software design, a formal notation based on statechart formalism is introduced. Furthermore, a design process is developed that arranges the activities needed in a sequential order and

38、 shows the related design outcomes. In Chapter 5, a number of case studies are given to demonstrate the applicability of the developed design methodology. The examples are derived from a complex reference system, a flexible assembly system. The achieved insights are evaluated in a concluding paragra

39、ph. Chapter 6 presents the developed computerized design tool for PLC software design on a conceptual level. The software is written in Visual Basic by using ActiveX controls to provide modularity and reuse in a web-based collaborative programming environment. Main components of the PLC software are

40、 modeling editors for the structural (modular) and the behavioral design, a layout specification interface and a simulation engine that can validate the developed model. Chapter 7 is concluding this thesis. It addresses the achievements with respect to the research objectives and questions. A critic

41、al evaluation is given alongside with an outlook for future research issues.中文翻译：动机可编程控制器(PLC)，计算设备的发明人理查德e.莫莉1968年 已被广泛应用于工业,包括制造系统,运输系统,化工设备等,不胜枚举. 当时,临立会取代hardwiredlogic软连线逻辑或所谓梯形图(左) 编程语言和视觉类似hardwired逻辑 并因而减少了配置时间从6个月至6天24,000莫莉,1999. 虽然基于PLC控制已经开始进入的地方, 基于PLC的控制仍将技术中的大部分工业应用将坚持由于其较高 性能,而且价格低廉,

42、和优越的可靠性,在恶劣的环境中. 此外,根据一项研究PLC市场的霜冻和苏利文1995, 增加的年销售量为15万PLCs每年提供硬件价值超过 8亿美元,已预言,尽管价格计算硬件正在稳步下降. 发明者的临立会,理查德e莫莉, 认为公平的PLC市场为50亿元的产业在当前时间. 虽然PLCs被广泛应用于工业实践, 编程控制器的控制系统仍然非常依赖试错. alike软件工程,PLC的软件设计,目前正面临两难的软件危机或以类似的方式. 莫莉强调自己在这方面最有力的说明穆迪和莫莉,1999年,第 110:如果楼房像软件项目,一个单一的啄木鸟可以摧毁文明. 尤其是, 实际问题可编程才能消除软件错误,以减少维修

43、费用的老梯子逻辑 节目. 虽然硬件成本PLCs正在不断下降, 减少扫描时间梯形图仍然是一个问题,在业,使低成本PLCs可 用. 在一般情况下,生产力的PLC发电是落后于其他领域,例如VLSI设计 那里有效率的计算机辅助设计工具的作法. 现有的软件工程方法,不一定适用于PLC的软件设计,因为PLC的编程需要同时考虑 硬件和软件. 软件设计变得,因此,越来越多的主要成本动因. 在许多工业设计项目,用于控制系统的设计与安装,预计进行测试和调试 PLC程序40998,1999. 此外, 当前PLC的控制系统是不恰当的设计,以支持日益增长的需求弹性和可重构制造 系统. 另外一个问题,推动需要有一个系统的

44、设计方法论,是不断增加的软件复杂的大型项目. 1.2目的和意义论文的目的这一论断,是建立一个有系统的软件设计方法 可编程操作自动化系统. 设计方法涉及高层次的描述基于国家转型模式处理自动化控制系统为离散事件系统, 分步设计过程,并订定设计规则提供指导和测量,以建立一个成功的设计. 有形的结果,这项研究是为了找到一个方法,以减少不确定性,在管理控制软件 发展过程中,即减少编程和调试的时间,它们的变化,越来越灵活的自动化系统 并使软件的重用,通过模块. 其目的是为了克服目前的规划策略,是基于经验的个人软件 开发商. 一个有系统的方法来设计PLC的软件可以克服的缺陷,在传统的方式编程制造控制系统,

45、可以产生广泛影响的几个工业应用. 自动化控制系统是模拟的正式语言或,equivalently,由国家机器. 正式交涉,提供一个高层次的描述系统的行为被控制. 国家机器可以分析评价,以查明他们是否达到预期目标. 其次, 状态机的描述提供了一种结构性的代表转达的合理要求和制约因素,如详细的安全规则. 第三, 明确界定的控制系统的设计成果,有利于代码自动生成一个有能力生产控制软件可执行商业 鲜明的逻辑控制可以减少编程的筹备时间及人力成本. 特别是,论文是有关对以下几方面. 客户导向的制造业,在现代制造系统的特点是产品和工艺创新, 成为客户导向的,因而很快地回应变化的系统要求. 一个重大的挑战就是要提

46、供有利的技术,可以在经济reconfigure自动化控制系统,以回应变动 需求和新的机遇. 设计和操作知识,可以重复使用的实时性,因此,给予相当大的竞争力,工业实践. 更高程度的自动化设计和软件质量的研究显示,编程方法自动化系统尚未 能赶上急速增加,使用电脑资源. 比如,编程PLCs仍依靠传统的节目风格,梯形逻辑图. 由于延误和资源规划的一大绊脚石的进步制造业. 测试和调试可能消耗超过50%的统筹分配给PLC程序设计. 标准电工60848,1999年; 国际电工委员会61131-3,1993年; IEC61499标准,1998年;ISO15745-1, 1999已形成固定和传播国家-国际艺术设

47、计的方法, 但他们通常不能参与推进知识有效的计划和制度设计. 有系统的方式会增加设计水平的自动化,通过重用现有软件组件, 并将提供方法,使大规模的制度设计管理. 同样的,这将提高软件的质量和可靠性,将相关的系统高安全标准 特别是那些有危害的环境影响,如机场的控制,以及公共铁路. 系统复杂的软件业,被视为表现破坏者和复杂发生器. 不断缩小的硬件价格有所斩获,需要软件的表现而言,代码优化和效益. 结果是,庞大而低效率的软件代码,一方面保持收益硬件性能 另一方面. 其次,软件proliferates变成复杂到无法控制的程度; 软件重新设计并维持必要的现代自动化系统变得几乎不可能. 尤其 PLC程序已

48、从几行代码是25年前为上千行代码 类似数目的算点. 提高安全性,比如新政策对防火 而灵活的现代自动化系统加上复杂的程序设计过程. 因此,生命周期的软件成本,是一项长期生长所需的全部费用. 80-90%这些费用都进入软件维修、调试, 改造和扩建,以满足不断变化的需求蒙斯etal. ,1998. 设计理论发展的今天,首要重点大部分设计开发研究,是基于机械和电器产品. 其中的副产品,这项研究是为了提高我们的基本了解设计理论和方法 扩大到该领域的工程系统设计. 一个制度设计的理论,进行大规模而复杂的制度尚未完全建立. 尤其至于如何简化复杂或复杂的设计任务,尚未解决的一个科学的方法. 此外, 建设桥梁设

49、计理论和最新成果的认识论的正式交涉,在计算机科学和运筹学 如离散事件系统建模,可以促进未来的发展,工程设计. 应用在逻辑硬件设计,从逻辑的角度来看, PLC的软件设计类似的硬件集成电路设计. 现代超大规模集成电路设计是非常复杂的数百万件,产品开发时间为3年,云妮,1996. 设计过程通常是分离成组件设计和系统设计阶段. 在构件设计阶段,单一功能的设计和论证. 在系统设计阶段,部件的整理和整个系统的性能和功能测试,通过模拟. 一般来说,一个完整的验证是不可能的. 因此,一个系统的方法,如对PLC的程序设计可能会影响到逻辑的硬件设计. 1.3结构的论文图1.1显示提纲以下论文. 第二章阐明了重大的挑战和问题进行研究,并论述了有关的背景和术语. 有人会争辩说,一个系统的设计PLC的软件能有助于更高的灵活性和可重构制造 系统. 重要的问题,就是如何处理复杂的工程设计等方面的设计和营运体系 将辩论. 研究方法适用于这个论断是介绍从讨论设计理论和方法是什么 可以从这一领域. 第三章涵盖了美国最