The Experts below are selected from a list of 2172 Experts worldwide ranked by ideXlab platform
Mengchu Zhou - One of the best experts on this subject based on the ideXlab platform.
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modeling simulation and control of flexible manufacturing systems a petri net approach
1999Co-Authors: Mengchu Zhou, Kurapati VenkateshAbstract:Flexible manufacturing systems - an overview Petri nets as an integrated tool and methodology in FMS design fundamentals of Petri nets modelling FMS with Petri nets FMS performance analysis Petri net simulation and tools performance evaluation of pull and push paradigms in flexible automation augmented-timed Petri nets for modelling breakdown handling real-time Petri nets for discrete event control comparison of real-time Petri nets and Ladder Logic diagrams an object-oriented design methodology for development of FMS control software scheduling using Petri nets Petri nets and future research.
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design of industrial automated systems via relay Ladder Logic programming and petri nets
Systems Man and Cybernetics, 1998Co-Authors: Mengchu Zhou, E TwissAbstract:For the past few decades, programmable Logic controllers (PLCs) using relay Ladder Logic (RLL) programming have been the workhorse for controlling event-driven industrial automated systems. RLL proved to be flexible compared to the hardwired RLL control implementation, due to its feature of software implementation. As automated systems become more complex, they also become more difficult to understand and maintain. It takes tremendous effort to accommodate specification changes (which are becoming frequent) to meet today's flexible automation needs. Several methods are emerging to overcome the shortcomings of RLL. Petri nets (PNs), initially proposed as a modeling tool, have been developed as such a method. This paper adopts an industrial-scale system to compare RLL and PN design methods so that the advantages of PN-like approaches are fully recognized. The criteria are: (i) the understandability that relates to the ability to evaluate the programmed Logic, to verify its correctness and to maintain the control system, and (ii) the flexibility that relates to the easy modification of Logic when the specification changes. This network takes an existing industrial system, conducts discrete event control designs by using both RLL programming and PN methods, and performs a comparative study on them. Together with previous comparison results using small-scale systems, the results of this study support that PN-like advanced discrete event control design methods are better than RLL in terms of the understandability and flexibility of the resulting control design.
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a comparison of relay Ladder Logic programming and petri net approach for sequential industrial control systems
International Conference on Control Applications, 1995Co-Authors: Mengchu Zhou, E TwissAbstract:For about the past two decades programmable Logic controllers (PLC's) using relay Ladder Logic (RLL) programming have been the workhorse for sequential industrial control systems. Petri nets are a methodology for modeling, evaluating and controlling discrete event systems (DES). This paper uses a theoretical Petri net based controller for an industrial control application. These two design methodologies are compared using an industrial design example. Comparisons are made on the ability to evaluate the programmed Logic, flexibility of the Logic and the ability to troubleshoot/debug the system.
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discrete event control design for manufacturing systems via Ladder Logic diagrams and petri nets a comparative study
1995Co-Authors: Kurapati Venkatesh, Mengchu Zhou, R J CaudillAbstract:Design methods for sequence controllers play a prominent role in advancing industrial automation. The increasing complexity and varying needs of modern discrete manufacturing systems have challenged the traditional design methods such as the use of Ladder Logic diagrams (LLDs) for programmable Logic controllers. The methodologies based on research results in computer science have recently received growing attention by academic researchers and industrial engineers in order to design flexible, reusable, and maintainable control software. Particularly, Petri nets (PNs) are emerging as a very important tool to provide an integrated solution for modeling, analysis, simulation, and control of industrial automated systems. However, in order to establish PNs as alternative to LLDs there is a need for benchmark studies to formally compare them. The contribution of this chapter is two fold. First, certain criteria are identified to compare LLDs and PNs in designing sequence controllers subject to the changing control requirements. The comparison is performed through a practical system after introducing ‘real-time Petri nets’ for discrete-event control purpose. Secondly, some analytical formulas and a methodology are developed to estimate the number of basic elements used in the PN and LLD designs prior to their constructions. The results will be useful for researchers and engineers to design control systems for complex industrial automated systems.
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comparing Ladder Logic diagrams and petri nets for sequence controller design through a discrete manufacturing system
IEEE Transactions on Industrial Electronics, 1994Co-Authors: Kurapati Venkatesh, Mengchu Zhou, R J CaudillAbstract:Design methods for sequence controllers play a very important role in advancing industrial automation. The increasing complexity and varying needs of modern discrete manufacturing systems have challenged the traditional design methods such as the use of Ladder Logic diagrams (LLDs) for programmable Logic controllers. The methodologies based on research results in computer science have recently received growing attention by academic researchers and industrial engineers in order to design flexible, reusable, and maintainable control software. Particularly, Petri nets are emerging as a very important tool to provide an integrated solution for modeling, analysis, simulation, and control of industrial automated systems. This paper identifies certain criteria to compare LLDs and Petri nets in designing sequence controllers and responding to the changing control requirements. The comparison is performed through a practical system after introducing "real-time Petri nets" for discrete-event control purposes. The results reported in this paper will help: (a) further establish Petri net based techniques for discrete-event control of industrial automated systems; and (b) effectively convince industrial practitioners and researchers that it is worthy and timely to consider and promote the applications of Petri nets to their particular discrete-event control problems. >
Kurapati Venkatesh - One of the best experts on this subject based on the ideXlab platform.
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modeling simulation and control of flexible manufacturing systems a petri net approach
1999Co-Authors: Mengchu Zhou, Kurapati VenkateshAbstract:Flexible manufacturing systems - an overview Petri nets as an integrated tool and methodology in FMS design fundamentals of Petri nets modelling FMS with Petri nets FMS performance analysis Petri net simulation and tools performance evaluation of pull and push paradigms in flexible automation augmented-timed Petri nets for modelling breakdown handling real-time Petri nets for discrete event control comparison of real-time Petri nets and Ladder Logic diagrams an object-oriented design methodology for development of FMS control software scheduling using Petri nets Petri nets and future research.
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discrete event control design for manufacturing systems via Ladder Logic diagrams and petri nets a comparative study
1995Co-Authors: Kurapati Venkatesh, Mengchu Zhou, R J CaudillAbstract:Design methods for sequence controllers play a prominent role in advancing industrial automation. The increasing complexity and varying needs of modern discrete manufacturing systems have challenged the traditional design methods such as the use of Ladder Logic diagrams (LLDs) for programmable Logic controllers. The methodologies based on research results in computer science have recently received growing attention by academic researchers and industrial engineers in order to design flexible, reusable, and maintainable control software. Particularly, Petri nets (PNs) are emerging as a very important tool to provide an integrated solution for modeling, analysis, simulation, and control of industrial automated systems. However, in order to establish PNs as alternative to LLDs there is a need for benchmark studies to formally compare them. The contribution of this chapter is two fold. First, certain criteria are identified to compare LLDs and PNs in designing sequence controllers subject to the changing control requirements. The comparison is performed through a practical system after introducing ‘real-time Petri nets’ for discrete-event control purpose. Secondly, some analytical formulas and a methodology are developed to estimate the number of basic elements used in the PN and LLD designs prior to their constructions. The results will be useful for researchers and engineers to design control systems for complex industrial automated systems.
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comparing Ladder Logic diagrams and petri nets for sequence controller design through a discrete manufacturing system
IEEE Transactions on Industrial Electronics, 1994Co-Authors: Kurapati Venkatesh, Mengchu Zhou, R J CaudillAbstract:Design methods for sequence controllers play a very important role in advancing industrial automation. The increasing complexity and varying needs of modern discrete manufacturing systems have challenged the traditional design methods such as the use of Ladder Logic diagrams (LLDs) for programmable Logic controllers. The methodologies based on research results in computer science have recently received growing attention by academic researchers and industrial engineers in order to design flexible, reusable, and maintainable control software. Particularly, Petri nets are emerging as a very important tool to provide an integrated solution for modeling, analysis, simulation, and control of industrial automated systems. This paper identifies certain criteria to compare LLDs and Petri nets in designing sequence controllers and responding to the changing control requirements. The comparison is performed through a practical system after introducing "real-time Petri nets" for discrete-event control purposes. The results reported in this paper will help: (a) further establish Petri net based techniques for discrete-event control of industrial automated systems; and (b) effectively convince industrial practitioners and researchers that it is worthy and timely to consider and promote the applications of Petri nets to their particular discrete-event control problems. >
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evaluating the complexity of petri nets and Ladder Logic diagrams for sequence controllers design in flexible automation
Emerging Technologies and Factory Automation, 1994Co-Authors: Kurapati Venkatesh, Mengchu Zhou, R J CaudillAbstract:This paper presents a methodology to evaluate the complexity of Petri nets (PNs) and Ladder Logic diagrams (LLDs) for sequence controllers design. Complexity of a design is characterized by the number of basic elements used to model the given control Logic. More specifically, this paper presents analytical formulas to estimate the number of basic elements to model certain building blocks of Logic modeling when PN and LLD are used. Also, by presenting a methodology to use these analytical formulas, this paper precludes the need for physically building the controllers by either PN or LLD for the comparison of their graphical complexity. The results are demonstrated by considering two examples of sequence controllers. Finally, the limitations of the present work are presented along with possible extensions for future research. >
E Twiss - One of the best experts on this subject based on the ideXlab platform.
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design of industrial automated systems via relay Ladder Logic programming and petri nets
Systems Man and Cybernetics, 1998Co-Authors: Mengchu Zhou, E TwissAbstract:For the past few decades, programmable Logic controllers (PLCs) using relay Ladder Logic (RLL) programming have been the workhorse for controlling event-driven industrial automated systems. RLL proved to be flexible compared to the hardwired RLL control implementation, due to its feature of software implementation. As automated systems become more complex, they also become more difficult to understand and maintain. It takes tremendous effort to accommodate specification changes (which are becoming frequent) to meet today's flexible automation needs. Several methods are emerging to overcome the shortcomings of RLL. Petri nets (PNs), initially proposed as a modeling tool, have been developed as such a method. This paper adopts an industrial-scale system to compare RLL and PN design methods so that the advantages of PN-like approaches are fully recognized. The criteria are: (i) the understandability that relates to the ability to evaluate the programmed Logic, to verify its correctness and to maintain the control system, and (ii) the flexibility that relates to the easy modification of Logic when the specification changes. This network takes an existing industrial system, conducts discrete event control designs by using both RLL programming and PN methods, and performs a comparative study on them. Together with previous comparison results using small-scale systems, the results of this study support that PN-like advanced discrete event control design methods are better than RLL in terms of the understandability and flexibility of the resulting control design.
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a comparison of relay Ladder Logic programming and petri net approach for sequential industrial control systems
International Conference on Control Applications, 1995Co-Authors: Mengchu Zhou, E TwissAbstract:For about the past two decades programmable Logic controllers (PLC's) using relay Ladder Logic (RLL) programming have been the workhorse for sequential industrial control systems. Petri nets are a methodology for modeling, evaluating and controlling discrete event systems (DES). This paper uses a theoretical Petri net based controller for an industrial control application. These two design methodologies are compared using an industrial design example. Comparisons are made on the ability to evaluate the programmed Logic, flexibility of the Logic and the ability to troubleshoot/debug the system.
R J Caudill - One of the best experts on this subject based on the ideXlab platform.
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discrete event control design for manufacturing systems via Ladder Logic diagrams and petri nets a comparative study
1995Co-Authors: Kurapati Venkatesh, Mengchu Zhou, R J CaudillAbstract:Design methods for sequence controllers play a prominent role in advancing industrial automation. The increasing complexity and varying needs of modern discrete manufacturing systems have challenged the traditional design methods such as the use of Ladder Logic diagrams (LLDs) for programmable Logic controllers. The methodologies based on research results in computer science have recently received growing attention by academic researchers and industrial engineers in order to design flexible, reusable, and maintainable control software. Particularly, Petri nets (PNs) are emerging as a very important tool to provide an integrated solution for modeling, analysis, simulation, and control of industrial automated systems. However, in order to establish PNs as alternative to LLDs there is a need for benchmark studies to formally compare them. The contribution of this chapter is two fold. First, certain criteria are identified to compare LLDs and PNs in designing sequence controllers subject to the changing control requirements. The comparison is performed through a practical system after introducing ‘real-time Petri nets’ for discrete-event control purpose. Secondly, some analytical formulas and a methodology are developed to estimate the number of basic elements used in the PN and LLD designs prior to their constructions. The results will be useful for researchers and engineers to design control systems for complex industrial automated systems.
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comparing Ladder Logic diagrams and petri nets for sequence controller design through a discrete manufacturing system
IEEE Transactions on Industrial Electronics, 1994Co-Authors: Kurapati Venkatesh, Mengchu Zhou, R J CaudillAbstract:Design methods for sequence controllers play a very important role in advancing industrial automation. The increasing complexity and varying needs of modern discrete manufacturing systems have challenged the traditional design methods such as the use of Ladder Logic diagrams (LLDs) for programmable Logic controllers. The methodologies based on research results in computer science have recently received growing attention by academic researchers and industrial engineers in order to design flexible, reusable, and maintainable control software. Particularly, Petri nets are emerging as a very important tool to provide an integrated solution for modeling, analysis, simulation, and control of industrial automated systems. This paper identifies certain criteria to compare LLDs and Petri nets in designing sequence controllers and responding to the changing control requirements. The comparison is performed through a practical system after introducing "real-time Petri nets" for discrete-event control purposes. The results reported in this paper will help: (a) further establish Petri net based techniques for discrete-event control of industrial automated systems; and (b) effectively convince industrial practitioners and researchers that it is worthy and timely to consider and promote the applications of Petri nets to their particular discrete-event control problems. >
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evaluating the complexity of petri nets and Ladder Logic diagrams for sequence controllers design in flexible automation
Emerging Technologies and Factory Automation, 1994Co-Authors: Kurapati Venkatesh, Mengchu Zhou, R J CaudillAbstract:This paper presents a methodology to evaluate the complexity of Petri nets (PNs) and Ladder Logic diagrams (LLDs) for sequence controllers design. Complexity of a design is characterized by the number of basic elements used to model the given control Logic. More specifically, this paper presents analytical formulas to estimate the number of basic elements to model certain building blocks of Logic modeling when PN and LLD are used. Also, by presenting a methodology to use these analytical formulas, this paper precludes the need for physically building the controllers by either PN or LLD for the comparison of their graphical complexity. The results are demonstrated by considering two examples of sequence controllers. Finally, the limitations of the present work are presented along with possible extensions for future research. >
B. Umamaheswari - One of the best experts on this subject based on the ideXlab platform.
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Supervisory control of an automated system with Ladder Logic programming and analysis using Petri nets
IEEE International Conference on Systems Man and Cybernetics, 2002Co-Authors: K. Latha, B. UmamaheswariAbstract:Complex automatic systems require high level discrete event control and low-level implementation. To date in industry, programmable Logic controllers dominate the application domain. Detailed analysis of the system with discrete event controller (PLC) is not readily available. A methodology of converting the LLD (PLC programming) into a Petri net is developed in this paper. The developed Petri net model captures the dynamics of the system and analyzes the qualitative and quantitative aspects of the system. One of the modeling tools of Petri net namely visual object net is used in this paper for simulation. It provides graphical, mathematical and visual modeling support.
