In this paper was analyzed a structure of existing regulators. For future automation there was presented suggested configuration of PLCs and communication networks. There is analyzed technological process control syst...
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In this paper was analyzed a structure of existing regulators. For future automation there was presented suggested configuration of PLCs and communication networks. There is analyzed technological process control system modernization stage. There are presented solutions for modernization of the existing process control systems.
The ongoing trend to bring larger and faster devices to the programmablelogic (PLD) is entering an exciting era with the advent of devices in the millions of gates and new feature sets designed to promote system-on-a...
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The ongoing trend to bring larger and faster devices to the programmablelogic (PLD) is entering an exciting era with the advent of devices in the millions of gates and new feature sets designed to promote system-on-a-chip design. Items such as embedded memory, phase-locked loops (PLL), and multifunctional input/output will become common, while design aids like larger functional blocks and intellectual property will help designers maintain high levels of productivity while using the devices to their utmost performance. These changes will not result in the ultimate PLD or PLD design environment, rather, they will reflect the dynamism of the programmablelogic industry, which like the device themselves, alters as necessary to meet the needs of its users.
A special purpose RISC (reduced instruction set computer) microprocessor for programmable logic controllers (PLC), named PLCRISC, is proposed. To develop an optimal PLCRISC, we analysed existing PLC programs currently...
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A special purpose RISC (reduced instruction set computer) microprocessor for programmable logic controllers (PLC), named PLCRISC, is proposed. To develop an optimal PLCRISC, we analysed existing PLC programs currently used in factories, with special attention to the instruction execution characteristics and features required for a high performance PLC processor. Based on this analysis, an optimal RISC-style instruction set and an architecture suitable for the required features are suggested. In particular, the instruction format, the instruction pipeline, and the detailed internal architecture are the significant characteristics of the proposed PLCRISC. The performance enhancement achieved with a PLCRISC is seen from a straightforward evaluation. ASIC implementation with VHDL is also discussed. The PLCRISC is under fabrication in a 0.8 mu m CMOS technology.
In order to obtain a safety electronic system of control, in general it will be necessary to assign a redundancy approach. Nevertheless this makes the equipments more expensive. Throughout this paper, a method based o...
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In order to obtain a safety electronic system of control, in general it will be necessary to assign a redundancy approach. Nevertheless this makes the equipments more expensive. Throughout this paper, a method based on dynamic logic is set out in order to achieve safety systems with programmable logic controllers.
A computer based simulation technique has been developed to aid the procurement and testing of programmable logic controllers (PLC) and condition monitoring software for electro-pneumatic and electro-hydraulic systems...
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A computer based simulation technique has been developed to aid the procurement and testing of programmable logic controllers (PLC) and condition monitoring software for electro-pneumatic and electro-hydraulic systems working in an industrial manufacturing environment. Condition monitoring, using measurable parameters such as pressure, flow rate and fluid quality, can provide a useful indication of the current running condition of such systems and a warning of possible mechanical failure. At relatively low cost, substantial improvements in the testing and development capability has been obtained.
The anticipated use of autonomous flexible manufacturing workcells in the near future has encouraged recent research efforts on the development of automatic supervisory-control methodologies. However, despite intensiv...
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The anticipated use of autonomous flexible manufacturing workcells in the near future has encouraged recent research efforts on the development of automatic supervisory-control methodologies. However, despite intensive research on the theoretical aspects of the control of flexible manufacturing workcells, modeled as discrete event systems (DESs), relatively little research has been reported on procedures for the implementation of DES-based supervisory controllers. In this paper, a generalized implementation methodology, which utilizes recent theoretical advances in conjunction with programmablelogic controller (PLC) technology, is presented. The two primary advantages of the proposed methodology are: (1) the utilization of control strategies, synthesized within a formal theoretical framework, that can be efficiently generated on-line and (2) the use of PLCs, which are currently the most suitable and widely employed industrial process control technology.
programmable Electronic Systems (PES) are a potentially good solution for safety protection applications. But a PES must utilize special circuits and special architectures to reduce the chances of it failing dangerous...
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programmable Electronic Systems (PES) are a potentially good solution for safety protection applications. But a PES must utilize special circuits and special architectures to reduce the chances of it failing dangerously. There are several critical design parameters to measure the effectiveness of these systems. Diagnostic 'Coverage Factor' is one of these parameters that affects all architectures. This paper explains the tools used to measure and verify the diagnostic capability of a PES. (C) 1998 Published by Elsevier Science Ltd.
Grafcet, and more recently IEC1131-3 SFC, have sought to provide a standardised, easy to interpret graphical programming technique for programming programmable logic controllers (PLCs). Both techniques represent attem...
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Grafcet, and more recently IEC1131-3 SFC, have sought to provide a standardised, easy to interpret graphical programming technique for programming programmable logic controllers (PLCs). Both techniques represent attempts to modify Petri nets to make them applicable to sequential control tasks. However, both depart significantly from the Petri net paradigm. In this paper Automation Petri Nets for Control (APNC) are defined which retain more of the features of generalised Petri nets. Marked Matrix Equations are presented for APNCs which naturally generate Marked Metric logiccontrollers. These are easily implemented on industrial and embedded PC's in high level programming languages. Grafcet, et plus récemment lEC1131-3 SFC, ont cherché á mettre á disposition une technique graphique standardisée et facile á intepréter de programer les automates programables. Les deux techniques représentent des essais de modification des réseaux de Petri afin de les rendre applicables au contrôle séquentiel de tâches. Cependant, toutes deux s'éloignent de façon significative du concept des réseaux de Petri. Dans cet article, les ”Automation Petri Nets for Control“ (APNC) sont définis; ils gardent plus de caractéristiques des réseaux de Petri généralisés. ”Marked Matrix Equations“ sont preséntées pour les APNC qui, naturellement génèrent un ”Marked Matrix logic Controller“ facilement implémenté dans des PC industriels et intégrés, avec des languages de programation de haut niveau.
As a result of pressure from personal computer (PC)-based systems, vendors are offering programmable logic controllers (PLC) users open architectures that allow third-party hardware and software interfaces, a wider se...
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As a result of pressure from personal computer (PC)-based systems, vendors are offering programmable logic controllers (PLC) users open architectures that allow third-party hardware and software interfaces, a wider selection of models based on size and cost, easier Windows-based programming, and increasing use of standard networking technology such as Ethernet transport control protocol/Internet protocol. All this still comes with the high input/output (I/O) counts, speed, ruggedness and reliability traditionally associated with PLCs, and pains have been taken to be sure the new PLC-based system will mesh with the equipment users already have on the plant floor.
Automated material flow is essential to the optimal performance of a flexible Manufacturing System (FMS). For those FMS for which material flow is carried nut using conveyors, the control of the conveyor system is the...
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ISBN:
(纸本)0780341171
Automated material flow is essential to the optimal performance of a flexible Manufacturing System (FMS). For those FMS for which material flow is carried nut using conveyors, the control of the conveyor system is the key to managing material delivery to several machines comprising the system. This pager describes a fuzzy logic-based control model far an FMS conveyor system Fuzzy logic technology is employed to realize PID control in real-time. Conveyor speed on each conveyor segment is controlled using fuzzy logic techniques to regulate the arrival rate of pallets to work stations, In this way, the production throughput of the FMS is maximized.
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