畢業(yè)設(shè)計(jì)plc中英文翻譯

1、<p><b>　　1 PLC英文資料</b></p><p>　　1.1 Motivation</p><p>　　Programmable Logic Controllers (PLC), a computing device invented by Richard E. Morley in 1968, have been widely used in

2、industry including manufacturing systems, transportation systems, chemical process facilities, and many others. At that time, the PLC replaced the hardwired logic with soft-wired logic or so-called relay ladder logic (RL

3、L), a programming language visually resembling the hardwired logic, and reduced thereby the configuration time from 6 months down to 6 days [Moody and Morley, </p><p>　　Although PC based control has started

4、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. Mor

5、eover, according to a study on the PLC market 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,

6、 though the prices of </p><p>　　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

7、 software design is facing the software dilemma or crisis in a similar way. Morley himself emphasized this aspect most forcefully by indicating [Moody and Morley, 1999, p. 110]:</p><p>　　`If houses were buil

8、t like software projects, a single woodpecker could destroy civilization.”</p><p>　　Particularly, practical problems in PLC programming are to eliminate software bugs and to reduce the maintenance costs of o

9、ld 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.</p><p>　　In

10、general, the productivity in generating PLC is far behind compared to other domains, for instance, VLSI design, where efficient computer aided design tools are in practice. Existent software engineering methodologies are

11、 not necessarily applicable to the PLC based software design because PLC-programming requires a simultaneous consideration of hardware and software. The software design becomes, thereby, more and more the major cost driv

12、er. In many industrial design projects, more than SO0/a o</p><p>　　In addition, current PLC based control systems are not properly designed to support the growing demand for flexibility and reconfigurability

13、 of manufacturing systems. A further problem, impelling the need for a systematic design methodology, is the increasing software complexity in large-scale projects.</p><p>　　1.2 Objective and Significance of

14、 the Thesis</p><p>　　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 s

15、tate transition models that treat automation control systems as discrete event systems, a stepwise design process, and set of design rules providing guidance and measurements to achieve a successful design. The tangible

16、outcome of this research is to find a way to reduce the uncertainty in managing the control so</p><p><b>　　2 PLC英文資料</b></p><p>　　A systematic approach to designing PLC software can

17、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

18、, equivalently, by state machines. Formal representations provide a high-level description of the behavior of the system to be controlled. State machines can be analytically evaluated as to whether or not they meet the d

19、esired g</p><p>　　Customer-Driven Manufacturing</p><p>　　In modern manufacturing, systems are characterized by product and process innovation, become customer-driven and thus have to respond qui

20、ckly to changing system requirements. A major challenge is therefore to provide enabling technologies that can economically reconfigure automation control systems in response to changing needs and new opportunities. Desi

21、gn and operational knowledge can be reused in real-time, therefore, giving a significant competitive edge in industrial practice.</p><p>　　Higher Degree of Design Automation and Software Quality</p>&

22、lt;p>　　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 conventi

23、onal programming style with ladder logic diagrams. As a result, the delays and resources in programming are a major stumbling stone for the progress of manufacturing industry. Testing and debugging may consume over 50% o

24、f the manpower allocated for the PLC program design. Standards [IEC 60</p><p>　　A systematic approach will increase the level of design automation through reusing existing software components, and will provi

25、de methods to make large-scale 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

26、 environment such as airport control, and public railroads.</p><p>　　System Complexity</p><p>　　The software industry is regarded as a performance destructor and complexity generator. Steadily s

27、hrinking 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 perfo

28、rmance on the other hand. Secondly, software proliferates into complexity of unmanageable dimensions; software redesign and maintenance-essential in modern automation systems-becomes</p><p><b>　　3 PLC英

29、文資料</b></p><p>　　Design Theory Development</p><p>　　Today, the primary focus of most design research is based on mechanical or electrical products. One of the by-products of this proposed

30、research 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

31、 developed. Particularly, the question of how to simplify a complicated or complex design task has not been tackled in a scientific way. Further</p><p>　　Application in Logical Hardware Design</p><

32、;p>　　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 y

33、ears [Whitney, 1996]. The design process 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

34、are aggregated and the whole system behavior and functionality is te</p><p><b>　　PLC</b></p><p>　　PLC（programmable logical controller）face ever more complex challenge these days. Whe

35、re once they quietly relays and gave an occasional report to a corporate mainframe, they are now grounded into cells, give new jobs and new languages, and are forced to compete against a growing array of control products

36、. For this year’s annual PLC technology update, we queried PLC makers on these topics and more.</p><p>　　Programming languages</p><p>　　Higher level PLC programming languages have been around fo

37、r some time, but lately their popularity has been mushrooming. As Raymond Lavelle, vice president and general manager, Siemens Energy and Automation. Inc, Programmable Controls Division, points out :”As programmable cont

38、rols are being used for more and more sophisticated operations, languages other than ladder logic become more practical, efficient, and powerful. For example, it's very difficult to write a trigonometric function usi

39、ng lad</p><p>　　PLCs in process control</p><p>　　Thus far, PLCs have not been used extensively for continuous process control. Will this continue? ”The feeling that I’ve gotten,” says Ken Jeanne

40、tte, manager, product planning, Series One and Series Six products, at GE Frame North America, "is that PLCs will be used in the process industry but not necessarily for process control.”</p><p>　　Sever

41、al vendors-obviously betting that the opposite will happen-have introduced PLCs optimized for process applications. Rich Ryan ,manager, commercial marketing, Allen-Bradley Programmable Controls Div, cites PLCs’ increasin

42、g use in such industries as food, chemicals, and petroleum. Ryan feel there are two types of applications in which they’re appropriate.”O(jiān)ne, "he says, "is where the size of the process control system that's

43、 being automated doesn’t justify DCS[distributed control systems].Wit</p><p>　　Bill Barkovtz, president of Triconex, predicts that "all future controllers that come out in the process control system bus

44、iness will embrace a lot more PLC technology and a lot more PLC functionality than they ever did before.”</p><p>　　Communications and MAP</p><p>　　Communications are vital to an individual autom

45、ation cell and to the automated factory as a whole. We've heard a lot about MAP in the last few years, and a lot of companies have jumped on the band wagon. Many, however were disappointed when a fully-defined and co

46、mpleted MAP specification didn’t appear immediately. Says Larry Kumara:”Right now , MAP is still a moving target for the manufacturers specification that is not final. Presently, for example, people are introducing produ

47、cts to meet the M</p><p>　　Because of this, many PLC vendors are holding off on full MAP implementations. Omron, for example , has an ongoing MAP-compatibility program, but Frank Newborn, vice president of O

48、mron’s Industrial Division, reports that because of the lack of a firm definition, Omron's PLCs don't yet talk to MAP.</p><p>　　Since it’s unlikely that an individual PLC would talk to broadband MAP

49、anyway, makers are concentrating n proprietary networks. According to Sal Provanzano, users fear that if they do get on board and vendors withdraw from MAP, they ‘ll pulse width modulation control system be the ones left

50、 holding a communications structure that’s not supported.</p><p>　　PLC Introduction</p><p>　　Programmable controller is the first in the late 1960s in the United States, then called Plc programm

51、able logic controller (Programmable Logic Controller) is used to replace relays. For the implementation of the logical judgment, timing, sequence number, and other control functions. The concept is presented Plc General

52、Motors Corporation. Plc and the basic design is the computer functional improvements, flexible, generic and other advantages and relay control system simple and easy to operate, s</p><p>　　In the mid-1970s,

53、the Plc has been widely used as a central processing unit microprocessor, import export module and the external circuits are used, large-scale integrated circuits even when the Plc is no longer the only logical (IC) judg

54、ment functions also have data processing, PID conditioning and data communications functions. International Electro technical Commission (IEC) standards promulgated programmable controller for programmable controller dra

55、ft made the following definition : program</p><p>　　First, high reliability, anti-interference capability;</p><p>　　Second，programming visual, simple;</p><p>　　Third, adaptability g

56、ood;</p><p>　　Fourth functional improvements, strong functional interface.</p><p>　　Programming controller introduction and future development</p><p>　　Motivation</p><p&g

57、t;　　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 facilities,

58、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 con

59、figuration time from 6 months down to 6 days [Moody and Morley, </p><p>　　Although PC based control has started to come into place, PLC based control will remain the technique to which the majority of indust

60、rial 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 of Frost and Sullivan [1995], an increase of the

61、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 </p><p>　　Though PLCs are widely used in industrial practice

62、, 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 way. Morley himself emph

63、asized this aspect most forcefully by indicating [Moody and Morley, 1999, p. 110]:</p><p>　　`If houses were built like software projects, a single woodpecker could destroy civilization.”</p><p>

64、　　Particularly, practical problems in PLC programming are to eliminate software bugs and to reduce the maintenance costs of old ladder logic programs. Though the hardware costs of PLCs are dropping continuously, reducing

65、 the scan time of the ladder logic is still an issue in industry so that low-cost PLCs can be used.</p><p>　　In general, the productivity in generating PLC is far behind compared to other domains, for instan

66、ce, 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

67、 simultaneous consideration of hardware and software. The software design becomes, thereby, more and more the major cost driver. In many industrial design projects, more than SO0/a o</p><p>　　In addition, cu

68、rrent PLC based control systems 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 method

69、ology, is the increasing software complexity in large-scale projects.</p><p>　　1.2 Objective and Significance of the Thesis</p><p>　　The objective of this thesis is to develop a systematic softw

70、are 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 stepw

71、ise design process, 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 so&

72、lt;/p><p>　　A systematic approach to designing PLC software can overcome deficiencies in the traditional way of programming manufacturing control systems, and can have wide ramifications in several industrial a

73、pplications. Automation control systems are modeled by formal languages or, equivalently, by state machines. Formal representations provide a high-level description of the behavior of the system to be controlled. State m

74、achines can be analytically evaluated as to whether or not they meet the desired g</p><p>　　Customer-Driven Manufacturing</p><p>　　In modern manufacturing, systems are characterized by product a

75、nd process innovation, become customer-driven and thus have to respond quickly to changing system requirements. A major challenge is therefore to provide enabling technologies that can economically reconfigure automation

76、 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.</p><p

77、>　　Higher Degree of Design Automation and Software Quality</p><p>　　Studies have shown that programming methodologies in automation systems have not been able to match rapid increase in use of computing r

78、esources. For instance, the programming of PLCs still relies on a conventional programming style with ladder logic diagrams. As a result, the delays and resources in programming are a major stumbling stone for the progre

79、ss of manufacturing industry. Testing and debugging may consume over 50% of the manpower allocated for the PLC program design. Standards [IEC 60</p><p>　　A systematic approach will increase the level of desi

80、gn automation through reusing existing software components, and will provide methods to make large-scale system design manageable. Likewise, it will improve software quality and reliability and will be relevant to system

81、s high security standards, especially those having hazardous impact on the environment such as airport control, and public railroads.</p><p>　　System Complexity</p><p>　　The software industry is

82、 regarded 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 les

83、s efficient software code on one hand outpaces the gains in hardware performance on the other hand. Secondly, software proliferates into complexity of unmanageable dimensions; software redesign and maintenance-essential

84、in modern automation systems-becomes</p><p>　　Design Theory Development</p><p>　　Today, the primary focus of most design research is based on mechanical or electrical products. One of the by-pro

85、ducts of this proposed research 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

86、system is not yet fully developed. Particularly, the question of how to simplify a complicated or complex design task has not been tackled in a scientific way. Further</p><p>　　Application in Logical Hardwar

87、e Design</p><p>　　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

88、development time of 3 years [Whitney, 1996]. The design process is normally separated into a component design and a system design stage. At component design stage, single functions are designed and verified. At system de

89、sign stage, components are aggregated and the whole system behavior and functionality is te</p><p><b>　　PLC</b></p><p>　　PLC（programmable logical controller）face ever more complex ch

90、allenge these days. Where once they quietly relays and gave an occasional report to a corporate mainframe, they are now grounded into cells, give new jobs and new languages, and are forced to compete against a growing ar

91、ray of control products. For this year’s annual PLC technology update, we queried PLC makers on these topics and more.</p><p>　　Programming languages</p><p>　　Higher level PLC programming langua

92、ges have been around for some time, but lately their popularity has been mushrooming. As Raymond Lavelle, vice president and general manager, Siemens Energy and Automation. Inc, Programmable Controls Division, points out

93、 :”As programmable controls are being used for more and more sophisticated operations, languages other than ladder logic become more practical, efficient, and powerful. For example, it's very difficult to write a tri

94、gonometric function using lad</p><p>　　PLCs in process control</p><p>　　Thus far, PLCs have not been used extensively for continuous process control. Will this continue? ”The feeling that I’ve g

95、otten,” says Ken Jeannette, manager, product planning, Series One and Series Six products, at GE Frame North America, "is that PLCs will be used in the process industry but not necessarily for process control.”</

96、p><p>　　Several vendors-obviously betting that the opposite will happen-have introduced PLCs optimized for process applications. Rich Ryan ,manager, commercial marketing, Allen-Bradley Programmable Controls Div

97、, cites PLCs’ increasing use in such industries as food, chemicals, and petroleum. Ryan feel there are two types of applications in which they’re appropriate.”O(jiān)ne, "he says, "is where the size of the process co

98、ntrol system that's being automated doesn’t justify DCS[distributed control systems].Wit</p><p>　　Bill Barkovtz, president of Triconex, predicts that "all future controllers that come out in the pro