This paper discusses the problems of the development and licensing of safety-related control systems, which are caused by the use of “new”-technologies like microcomputer systems. It describes why the classical prin...
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This paper discusses the problems of the development and licensing of safety-related control systems, which are caused by the use of “new”-technologies like microcomputer systems. It describes why the classical principles to proof the safety of hard-wired equipment such as relay-circuits cannot be applied to more complex hardware/software-systems. Additionally to physically induced faults (e.g. hardware failures), the aspects and effects of human faults (e.g. design errors, documentation errors) have to be considered carefully. Guidelines have been written by several organizations, intended to give rules how to develop safety-related systems which are as error free as possible from the very beginning and which can easily be verified by licensing personnel. The paper shows, that many of these guidelines and rules can be included in a computer-aided development support system, thus eliminating the need to control the application of these guidelines and rules by a licensing authority. The properties of computer-aided development support systems (using the EPOS- system as an example) are presented, showing their means for efficacious fault-avoidance and fault-removal during all phases of the system development and how thereby the safety problems of complex systems can be mastered. Especially it is shown that a specification language combined with an analysing program system, is a very powerful tool to detect many classes of specification, design and programming errors in the early phases of the development.
Due to the high complexity of computer based safety-related systems the question how to cope with the effects of human errors (e.g. specification-, design errors) which may occur during the whole life cycle of a syste...
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Due to the high complexity of computer based safety-related systems the question how to cope with the effects of human errors (e.g. specification-, design errors) which may occur during the whole life cycle of a system becomes more and more important. In fact all software errors can be traced back to human errors. Therefore a great number of guidelines has been published by various organizations intended to establish rules how to develop (specify, design, document, verify etc.) safety-related systems which are as error-free as possible from the very beginning. This paper discusses how those guidelines can be automatically ensured by computer-aided development support systems, using the EPOS-system as an example. Thereby the fault-avoidance features of the development support system EPOS which - positively influence the factors, identified to cause the occurance of human errors - substitute human error-prone methods by automated ones are presented. Furthermore the paper demonstrates in a second part how this system also provides tools for efficacious fault-detection and fault-removal during all phases of system development. It is especially shown that a specification language combined with an analysing program system, is a very powerful tool to detect many classes of specification and design errors as early as possible.
The processcontrol methods of the blast furnace at Koverhar have been developed stepwise over the last ten years. The first step included improvements of such subsystems as burden compositions-, tuyere level-, burden...
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The processcontrol methods of the blast furnace at Koverhar have been developed stepwise over the last ten years. The first step included improvements of such subsystems as burden compositions-, tuyere level-, burden distribution-, and tapping control. The second step aimed at long term control of the whole blast furnace based on computer models, which were used to analyze the process state. The gains in fuel rate and productivity which were achieved by these methods are shown in Fig.l and later discussed by means of the *** experience obtained during this work has been used in the third step, which consists of a user-oriented interactive process supervising system. The paper describes the third step, the implementation of the supervising system, its structure and the operational results achieved.
作者：
BULL, DNDaniel N. Bull
Ph.D. is a consultant in fermentation technology and president of Satori Corporation P.O. Box 1730 Montclair N.J. 07042. (201) 783-9787.REFERENCES Graff G.M. Short H. and Keene J.1983. Gene-splicing methods move from lab to plant. Chem. Eng.90: 22-27.|ISI|Broda P.1979. p. 1-3. Plasmids. W. H. Freeman Oxford and San Francisco.Donoghue D.J. and Sharp P.A.1978. Construction of a hybrid bacteriophage-plasmid recombinant DNA vector. J. Bact.136: 1192-1196.|PubMed|ISI|ChemPort|Bok S.H. Hoppe D. Mueller D.C. and Lee S.E.1983. Improving the production of recombinant DNA proteins through fermentation development. Abstract from 186th ACS Natl. Mtg. Washington D.C. Sept. 1.Maniatis T. Fritsch E.F. and Sam-brook J.1982. p. 88. Molecular Cloning. Cold Spring Harbor Laboratory. Guidelines for research involving recombinant DNA molecules June 1983
Fed. Reg.48: 24556-24581. Modifications of physical containment recommendations for large-scale uses of organisms containing recombinant DNA molecules. 1983. Recomb. DNA Tech. Bull.6: 69-70.Bull D.N. Thoma R.W. and Stinnett T.E.1983. Bioreactors for submerged culture. In:Adv. in Biotechnological Proc. A. Mizrahi and A. L. van Wezel (eds.) 1: 1-30.Schmidli B.L. and Swartz R.W.1982. Design considerations for aseptic fermentation. Presentation at 184th ACS Natl. Mtg. Kanas City MO.Sittig W.1982. The present state of fermentation reactors. J. Chem. Tech. Biotechnol.32: 47-58.|ISI|Strek F.1963. Intl. Chem. Eng.3: 533.Uhl V.W. and Gray J.B.1996. Mixing Theory and Practice Vol. I. Academic Press New York.Peters M.S. and Timmerhaus K.D.1968. p. 542. Plant Design and Economics for Chemical Engineers. McGraw-Hill New York.Dickey D.S. and Hicks R.W. Fundamentals of agitation. Chem. Eng.83: 93-100.Oldshue J.Y.1983. Fluid mixing technology and practice. Chem. Eng.90: 82-108.Kipke K.D.1981. Heat transfer in aerated non-Newtonian fluids. Abstract from 2nd Eur. Cong. Biotech. Eastbourne UK April 5-10.Blakebrough N. McM
A new component of the development support system EPOS for the analysis of the real-time behaviour of automation systems which is a basis for dynamic tests will be introduced. After a short description of EPOS-R and t...
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A new component of the development support system EPOS for the analysis of the real-time behaviour of automation systems which is a basis for dynamic tests will be introduced. After a short description of EPOS-R and the design objects available in EPOS-S, the interactive simulation system will be described. The functioning, the operation of the interactive simulation system as well as the graphic and textual documents produced by it will be demonstrated by an example. The parts of the simulation system which have already been implemented and the planned further expansion of the simulation system will be shown.
The computerised acquisition of the engine-mapping (Otto-Motor) can be done quickly and reliably using automatic closed-loop control of the torque and manifold pressure, whereby the throttle valve position is the actu...
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The computerised acquisition of the engine-mapping (Otto-Motor) can be done quickly and reliably using automatic closed-loop control of the torque and manifold pressure, whereby the throttle valve position is the actuating variable. In the whole operation range of the test-motor the amplification properties of the plant change very strongly, so that an identification is required. It will be discussed how an automatic off-line identification of nonlinear control plants was thought up and brought to reality. By the identification, various values of the motor speed as plant disturbance were taken into account. The identification process by the microcomputer makes it possible to realize test adaptions to various test-motors without high qualified personell. There is a demand for simple operator interface to the automatic system. The solution to these problems as well as the structure of the whole real-time microcomputer program will be described. The dynamic control properties of this concept when applied to real test-motors will be discussed.
Based on a brief introduction into the specification and design system EPOS its real-time features are presented including an explanation of the formulation, evaluation and documentation means. EPOS is oriented to a b...
The engineering activities of designing and implementing processcontrol systems including realtime computer hardware and software are considered. Several models of the design process are discussed. general design-lev...
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The engineering activities of designing and implementing processcontrol systems including realtime computer hardware and software are considered. Several models of the design process are discussed. general design-level and design-type oriented model is introduced, defining the categories of algorithmic, operational and auxiliary design. Based on this model, the design methodologies are classified. Design support systems are especially discussed, stating requirements to cope with the needs of realtime automation systems. The computer aided support (system EPOS is explained. It is claimed that many of the problems that plague the design of real-time automation systems now, may be alleviated eventually by using computer aided support systems.
Based on a brief introduction into the specification and design system EPOS its real-time features are presented including an explanation of the formulation, evaluation and documentation means. EPOS is oriented to a b...
Based on a brief introduction into the specification and design system EPOS its real-time features are presented including an explanation of the formulation, evaluation and documentation means. EPOS is oriented to a broad community of engineers designing,operating and maintaining automation systems. The features to express the real-time behaviour are explained by a basic description model for general real-time applications.
The design of the automation system for a distribution process with the computer-aided specification and design technique EPOS will be presented showing some of its characteristic features. After a short description o...
The design of the automation system for a distribution process with the computer-aided specification and design technique EPOS will be presented showing some of its characteristic features. After a short description of the technical process and the general automation tasks, the requirement specification using EPOS-R and the functional design with the aid of EPOS-S are demonstrated. Some of the main advantages of EPOS for the design of automation systems are discussed including its properties for analysis and documentation.
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