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The paper is focused on the modeling of a digital twin (DT) through a circuit simulation and artificial intelligence (AI) analysis to determine the effects of disturbances and noise in optocoupler devices integrated into programmable logic controller (PLC) systems. Specifically, the DT analyzes the parametric and the predicted simulations about the sensitivity of the optocouplers versus noise and interference to provide possible corrective actions, compensating for the distortion of the output signal. The model is structured into two main data processing steps: the first is based on the circuit simulation of the optocoupler noise coupling by highlighting the time-domain sensitivity aspects and the frequency behavior of the coupled signals; the second one estimates the predicted disturbed signal by means of supervised random forest (RF) and unsupervised K-Means algorithms to provide further elements to prevent corrective solutions by means of risk maps. This work is suitable for Industry 5.0 scenarios involving machine control supported by AI-based DT platforms. The innovative elements of the proposed model are the DT features of scalability and modularity; the spatial multidimensionality, able to couple the effects of different undesired signals; and the possibility to simulate the whole PLC system, including its control circuits. [ABSTRACT FROM AUTHOR]

An appropriate control and measurement system is one of the elements that allows for the safe and effective operation of a technological installation. Such a system may have a diverse structure that corresponds to the expectations and needs of its user. The devices of various manufacturers, including PLC (programmable logic controllers), can be used as a source of measurement data. This enables flexible measurement–control installations, which are adapted to the technological installations, to be built. This paper presents a system, which was created by the authors, for monitoring the temperature, pressure and flow rate of fluids. It uses the operational and IT properties of the PLC and is adapted to an existing installation on the test stand for multiphase spraying processes. In addition, as a part of the research, an application written in Python language, which allows collected data to be displayed, stored and exported, was implemented. [ABSTRACT FROM AUTHOR]

A set of DC pulse devices was built to measure the 5 mm × 10 mm YBCO sheet in order to evaluate the impact of thermal effect on the superconducting I-V curve (77 K, self-field). Firstly, metal organic deposition method was used to prepare YBCO precursor film on a 5 × 10mm2 lanthanum aluminate single crystal. With the aid of a mask plate, a 15-W laser was used to graphically process the YBCO film after pyrolysis and sintering, or before oxygen absorption, so that the silver gel curing and YBCO oxygen absorption processes could be performed simultaneously. In order to realize two modes of continuous loading current and pulse loading current, a set of power supply and test equipment consisting of a Keithley 6500 multimeter, a Keithley 2280 power supply, two simple programmable controllers, a special fixture, and a stepping motor with deceleration device was designed. This equipment is used to test Tc and Ic of graphically processed YBCO film. YBCO film displayed comparable critical current values in both continuous loading current mode and pulse loading current mode at the same current loading rate. After YBCO film enters the stage of loss of superconductivity, the method of pulse loading current shows lower resistivity than that of continuous loading current, and the ratio of the two resistivities increases further with the increasing of current, which may be because the method of pulse loading current provides more sufficient heat dissipation interval for YBCO. [ABSTRACT FROM AUTHOR]

Design of digital control systems is often based on use of Programmable Logic Controllers (PLC). Such devices offer a broad variety of functions that can be organized in blocks independently or in hierarchical structures. Such an organization can lead to cumulative delays in reaction time of digital outputs of the control system. In the paper there are described results of research aimed to determine dependencies of various aspects of designing programs for Programmable Logic Control devices influencing the effective time of reaction of digital outputs. Research method is presented, assumptions are made, and experiments are described and discussed. Observations of system behavior are presented for selected control tasks and different control situations. Research results are presented and discussed, conclusion is drawn, and areas of future work are identified. [ABSTRACT FROM AUTHOR]

Artificial intelligence techniques for pneumatic robot manipulators have become of deep interest in industrial applications, such as non-high voltage environments, clean operations, and high power-to-weight ratio tasks. The principal advantages of this type of actuator are the implementation of clean energies, low cost, and easy maintenance. The disadvantages of working with pneumatic actuators are that they have non-linear characteristics. This paper proposes an intelligent controller embedded in a programmable logic device to minimize the non-linearities of the air behavior into a 3-degrees-of-freedom robot with pneumatic actuators. In this case, the device is suitable due to several electric valves, direct current motors signals, automatic controllers, and several neural networks. For every degree of freedom, three neurons adjust the gains for each controller. The learning process is constantly tuning the gain value to reach the minimum of the mean square error. Results plot a more appropriate behavior for a transitive time when the neurons work with the automatic controllers with a minimum mean error of ± 1.2 mm. [ABSTRACT FROM AUTHOR]

This article represents research regarding use of pneumatic linear actuator. A pneumatic linear drive is a device that creates motion in a straight line. The linear drive with solenoid in this manuscript is a pneumatic actuator. The pneumatic linear drive works only with compressed air. Compressed air usually has a pressure of between 2•105 Pa and 6•105 Pa. Linear drive with solenoid can be used for various applications, including pulling/pushing, pick-and- place applications or lifting/moving. After Introduction, the authors study two pneumatic circuits using linear drive with solenoid coupling. In fact, the first pneumatic scheme in this paper has only one device (linear drive 1-1). But, the second pneumatic circuit has two actuators (linear drives 2-1 and 2-2). Further on, the authors present two electro-pneumatic circuits. In any case, a simple electro-pneumatic circuit that has a linear drive with solenoid coupling. Moreover, the second electro-pneumatic system has a linear drive with solenoid coupling and PLC (Programmable Logic Controller). The pneumatic and electro-pneumatic circuits given in this manuscript are made using FluidSim software from Festo. [ABSTRACT FROM AUTHOR]

A fully-submerged bottom-standing 1.5 MW wave energy converter (WEC) equipped with a membrane-pump system is under development for installation at a test site off the coast of Pembrokeshire, Wales, UK. The system comprises several flexible-membrane air cells that are compressed and sucked by the action of the waves, rectifying valves, low-pressure and high-pressure ducts, and a unidirectional air turbine that drives an electrical generator. This two-part paper reports the design and testing of an effective control law to be implemented into the programmable logic controller of the membrane-pump turbine-generator set, allowing efficient and safe operation for the wave climate at the Pembrokeshire test site. Part 1 of this paper concerns developing the design strategy of the control laws, the numerical model, and the performance evaluation of the WEC power take-off system. A genetic algorithm is used to design control laws to maximise each sea state's WEC time-average efficiency. An adaptive control algorithm is devised by cross-correlating the control laws parameters and the rotational speed. The final result is a control law that uses input the rotational speed signal and airflow density. It adapts to the sea state conditions while maximising the time-average total efficiency of the membrane-pump WEC for deployment off the Pembrokeshire coast. • A genetic algorithm used to design control laws. • Torque versus rotational speed control-laws studied using Bézier curves. • Adaptive control devised by correlating control parameters and rotational speed. • The control law uses as input the rotational speed and airflow density. • A one-parameter adaptive control law provides good performance. [ABSTRACT FROM AUTHOR]

Industry 4.0 proposes the use of 5G networks to support intra-factory communications in replacement of current communication practices. 5G networks offer high availability, ultra-low latency, and high bandwidth, and allow the allocation of computational resources closer to the factories for reducing latency and response time. In addition, artificial intelligence can help in making smart decisions to improve the industrial and logistic processes. This work presents an interesting use case that combines Industry 4.0, 5G networks, and deep learning techniques for predicting the malfunctioning of an automatic guided vehicle (AGV) by exclusively using network traffic information and without needing to deploy any meter in the end-us-er equipment AGV and programmable logic controller (PLC). The AGV is connected through a 5G access to its PLC, which is deployed and virtualized in a multi-access edge computing infrastructure. A complete set of intensive experiments with a real 5G network and an industrial AGV were carried out in the 5TONIC environment, validating the effectiveness of this solution. [ABSTRACT FROM AUTHOR]

The protection of power system is an essential trait in a huge network to efficiently detect and isolate the sections undergoing faults or abnormal behaviour. The key components of a protection scheme include circuit breakers, relays, switchgears and fuses which employ communication from one station to another to achieve high-speed tripping. The automation of these components at the laboratory level using programmable logic controller (PLC) along with supervisory control and data acquisition (SCADA) system owns paramount importance for intelligent decision making, sensing, actuating, monitoring and maintaining the record in the host server. This paper discusses such a technique for conventional power system protection laboratory at a new level of development to promote a control system through PLC and SCADA. The control system has indication of over and under values of voltage, load and frequency, which can trigger malfunctioning of equipment and must be rectified. Furthermore, ground fault and inverse current indication are added to the system for monitoring and controlling purposes. The proposed system enhances the efficiency and safety of the expensive equipment and the personnel to the next level and also introduces new standards of automated protection schemes for modern technical institutes. [ABSTRACT FROM AUTHOR]

A fully-submerged bottom-standing 1.5 MW wave energy converter (WEC) equipped with a membrane-pump system is being developed for installation at a test site off the coast of Pembrokeshire, Wales, UK. The system comprises several flexible-membrane air-cells that are compressed and sucked by the action of the waves, a system of rectifying valves, low-pressure and high-pressure ducts and a unidirectional air turbine that drives an electrical generator. This two-part paper reports the design and testing of an effective control law to be implemented into the programmable logic controller of the membrane-pump turbine-generator set, allowing efficient and safe operation for the wave climate at the Pembrokeshire test-site. Part 2 of this paper focuses on the experimental investigation at the IST variable flow test rig of the real-time control algorithm described in Part 1 of this paper, using a 1:2.4 turbine scale model. Tests were performed for five sea-states and two turbine model average rotational speeds. Experimental results reveal that the control law proposed for the Pembrokeshire mWave turbine-generator set, based only on the turbine rotational speed and airflow density measurements, is effective and of a simple implementation. Fine fitting between the model testing results validates the performed scaling of the variables related to the time-dependent turbine-generator operation, as well as the numerical model of the system described in Part 1. • The turbine-generator set real-time control algorithm was experimentally studied. • Tests were performed for five sea-states and two turbine model average rotational speeds. • The control law based on the turbine rotational speed and airflow density is effective. • Model testing results validate the scaling of the turbine-generator operation time-dependent variables. [ABSTRACT FROM AUTHOR]

The paper presents the automation of a concrete plant, with the help of PLCs (programmable logic controller). For the development of the development program, we used EASY-SOFT, which allows the use of different types of relays such as: EASY 500, EASY 700 and EASY 800. In the works we exemplified five automations of the most important processes underlying a concrete plant. [ABSTRACT FROM AUTHOR]

A new electronic seeding device was designed for large-sized seeds, such as soybean, corn, and peanuts, that supports an independent electronic-controlled seeding process. The developed seeding device consists of a programmable logic controller, pulse generator, stepper motor, and stepper motor driver. Based on the Box–Behnken Design model, the effects of different factors on the plant spacing control were analyzed, and the control parameters of the seeding system were optimized by correlation analysis. Through performance tests, the results of the research showed that the coefficient of variation of plant spacing was found to be affected by the interaction between shaft speed and belt speed, in which the belt speed was dominant. And the optimal control conditions by using Box–Behnken Design model are as follows: the seed shaft speed was 0.60 r/s, the soybean hundred-grain weight was 22 g, and the belt speed was 1.5 m/s. The results of the experiments showed that the socket-roller seeding device successfully completed the seeding test, and its performance index was in accord with the applicable standards for single grain precision seeding equipment. [ABSTRACT FROM AUTHOR]

In industrial automation, there are numerous use cases for a model representing the equipment's sequence of operations. Not only can such a model be used as a debugging aid, allowing users to observe the current state of the machinery at a glance, but it also can serve as a foundation for process improvements. Annotated process models can help pinpoint bottlenecks within the system, and a combination of models obtained from identical machines can be used to create a best-case baseline to which the devices can be optimised. Typically, the models used for such activities have been created during the equipment's design phase, which means that many of the changes made during commissioning, start-up, and production are not reflected. The research domain of process mining suggests that an accurate model can be obtained from an activity log. Since most industrial processes are controlled by Programmable Logic Controllers (PLCs), which offer the capability of external access through Open Platform Communications (OPC), such a log can be created automatically. The theory is that process mining algorithms can then be used to discover the desired model from the data recorded. Unfortunately, it turns out that this whole procedure is a game of chance. The quality of the discovered models strongly depends on the logged data. Not only can the records be flawed, but also the information needed to discover a complete model might not have been observed at all. To better judge the quality of the discovered models, numerous quality metrics have been proposed, which in the authors' opinion are a good guess at best. The industrial automation domain demands complete models, which cannot be guaranteed by any process mining algorithm unless it is known that the log contains all the data needed. This paper shows that for industrial equipment, it is possible to reason through the evaluation of a single recorded case, which case traces are required to guarantee that the discovered model will be complete. In the next step, the authors then introduced the concept of 'trace induction', which takes advantage of the fact that a PLC controls the observed processes. A minor change within the PLC's logic is used to force the process to execute the desired traces on demand. The resulting, minimalistic log can then be analysed by the αLC-algorithm to create a guaranteed complete, model. [ABSTRACT FROM AUTHOR]

This paper gives a medium range of a complete jaggery production unit. In order to satisfy the needs of sugarcane cultivators in all aspects with this project. It is the worth mentioning thing for both the cultivators and consumers. Coming to the part of technical area using programmable logic controller it completely process the production from initial stage to final stage. It involves various types of operation in different stages. Through proper coding used in the PLC and also via dedicated pins in the PLC the process is easily coordinate with back to back operation. It is a kind of domestic sugarcane production unit which is used for sugarcane cultivators. It is a simple process, compact and most reliable product. It consume less time. The jaggery powder obtained is completely natural and it does not show any effect towards health. Sugar contains empty calories whereas jaggery contains various minerals and vitamins so it provide energy for longer time. [ABSTRACT FROM AUTHOR]

Road tunnels are important part of traffic infrastructure not only for shortening the paths in mountainous regions or in towns but also they increase economical effectiveness. Occurrence of traffic accidents in the tunnel is less common, but consequences can be more serious. The contribution shows the simulation of fire in a road tunnel through programmable logic controller (PLC) based simulator. Fire detection in the tunnel model is realized by FibroLaser. Influence of the pressure difference for various fire scenarios, types of vehicle on the air speed, etc. is counted by evaluation of the average temperature in the fire section. [ABSTRACT FROM AUTHOR]

Water is a vital resource for the chemical, paper, steel and petroleum refining industries. Usually, industries use an enormous amount of water to flush the impurities and to cool down the products. As the industries are in need of water for multiple purposes, they tend to reuse water by a mechanism called Filtering. In the existing conventional filters, the filter elements are cleaned manually when it gets clogged, leading to more manpower and longtime. In Automatic back-wash filtering system, when filter elements get clogged, a pressure difference is created between inlet and outlet valve. This is sensed by a differential pressure sensor connected to the Programmable Logic Controller which initiates the backwash cycle that automatically cleans the filter elements. An alarm and Human Machine Interface display are also provided for the purpose of continuous monitoring and troubleshooting. The proposed Automatic back-wash filtering system is more efficient and overcomes the constraints of conventional filters. [ABSTRACT FROM AUTHOR]

A light-weight software-implemented fault injection (SWIFI) testing approach is introduced, focusing on technical process faults and system faults. The reaction of automated production systems (aPSs) and their programmable logic controller (PLC) software to these faults is tested. In order to tailor the testing approach to the aPS domain in industrial practice, our test generation is based on a classification of possible deviations, i.e. a classification of possible technical process and system faults as the PLC perceives them. As a result, both specification and test execution become more efficient for practitioners. Furthermore, the test specification is tailored for execution on IEC 61131-3 programming environments. In this, the execution of test cases both against simulation or the real aPS, is enabled. [ABSTRACT FROM AUTHOR]

This paper reports research undertaken to develop a user-friendly home energy monitoring system which is capable of collecting, processing and displaying detailed usage data. The system allows users to monitor power usage and switch their electronic appliances remotely, using any web enabled device, including computers, phones and tablets. The system aims to raise awareness of consumer energy use by gathering data about usage habits, and displaying this information to support consumers when selecting energy tariffs or new appliances. To achieve these aims, bespoke electrical hardware, or ‘ nodes ’, have been designed and built to monitor power usage, switch devices on and off, and communicate via a Wi-Fi connection, with bespoke software, the ‘ server ’. The server hosts a webpage which allows users to see a real-time overview of how power is being used in the home as well as allowing scheduled tasks and triggered tasks (which respond to events) to be programmed. The system takes advantage of well standardised networking specifications, such as Wi-Fi and TCP, allowing access from within the home, or remotely through the internet. The server runs under Debian Linux on a Raspberry Pi computer and is written in Python, HTML and JavaScript. The server includes advanced functionality, such as device recognition which allows users to individually monitor several devices that share a single node . The openPicus Flyport is used to provide Wi-Fi connectivity and programmable logic control to nodes . The Flyport is programmed with code compiled from C. [ABSTRACT FROM AUTHOR]

In this paper, a data-driven process controller is designed and implemented onboard a typical marine vessel for optimal variable-speed pump operation, leading to the energy efficiency optimization of its central cooling water system. To match variable flow rate requirements due to changes in the vessel's operational profile with respect to plant limitations, real-time process measurements are used as feedback signals to adjust the parameters and set-points of a data-driven process controller with self-tuned proportional–integral–differential control loops, which is realized through a commercial programmable logic controller and regulates the speed of sea water cooling pumps in order to maximize power saving potential during sea-going and cargo unloading periods. Data-driven control establishes system dynamics according to process parameter variation and ensures system reliability through parameter monitoring, regardless of the controlled plant model. The plant power saving potential is initially examined through a practical case study, whereas experimental results provided after the proposed control system retrofit installation onboard a tanker vessel show significant power balance improvement and reduction of diesel generator fuel consumption compared to existing pump throttle control methods, verifying that marine industry can be greatly benefited from this energy efficiency upgrade. [ABSTRACT FROM PUBLISHER]

The paper suggests a technique for solving the matrix/set covering problem in all programmable systems-on-chip. A novel very fast hardware accelerator is proposed and implemented in the programmable logic (PL) of a Xilinx Zynq microchip. The accelerator is managed by software running in the processing system (ARM Cortex-A9) available on the same microchip and communicating with the PL through high-speed interfaces. The results of implementation, experiments, and comparisons demonstrate significant speedup comparing to software running in general-purpose PC and in the ARM. [ABSTRACT FROM AUTHOR]

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Abstract: The work presents a dynamic Bayesian networks (DBN) modeling of series, parallel and 2-out-of-3 (2oo3) voting systems, taking account of common-cause failure, imperfect coverage, imperfect repair and preventive maintenance. Seven basic events of one, two or three component failure are proposed to model the common-cause failure of the three-components-systems. The imperfect coverage is modeled in the conditional probability table by defining a coverage factor. A multi-state degraded component is used to model the imperfect repair and preventive maintenance. Using the proposed method, a DBN modeling of a subsea blowout preventer (BOP) control system is built, and the reliability and availability are evaluated. The mutual information is researched in order to assess the important degree of basic events. The effects of degradation probability, failure rate and mean time to repair (MTTR) on the performances are studied. The results show that the repairs and maintenance can improve the system performance significantly, whereas the imperfect repair cannot degrade the system performance significantly in comparison with the perfect repair, and the preventive maintenance can improve the system performance slightly in comparison with the imperfect repair. In order to improve the performance of subsea BOP control system, the single surface components and the components with all-common-cause failure should given more attention. The influence of degradation probability on the performance is in the order of PLC, PC and ES. The influence of failure rate and MTTR on the performance is in the order of PLC, ES, PC, DO, DI and AI. [Copyright &y& Elsevier]

Abstract: This work presents a design and installation of solar dish concentrator (SDC), simple solar collector and modified boiler for brackish water desalination. The design of two axes tracking system is performed using an open-loop control based on programmable logic controllers (PLC). Glass mirrors are used as reflective surface for dish concentrator. A coiled black rubber hose is used to preheat brackish water before feeding to the boiler. A mini single slope-air tight solar still is designed and installed at the focus of dish concentrator which is used as a boiler. The automatic tracking system, new boiler design; and with and without preheating of brackish water are investigated. The developed desalination system is evaluated and compared with the conventional solar still (CSS). The results indicated that, the daily average of distillate water was 6.7l/m2/day for SDC with preheating of brackish water, while the distillate productivity was 1.5l/0.5m2/day for CSS. In the present study, the daily average efficiency of SDC and CSS was 68 and 34%, respectively. The increase in distillate production for SDC is about 244% and 347% higher than that of CSS without and with preheating, respectively. [Copyright &y& Elsevier]

Programmable memory built-in self-test (PMBIST) is an attractive approach for testing embedded memory. However, the main difficulties of the previous works are the large area overhead and low flexibility. To overcome these problems, a new flexible PMBIST (FPMBIST) architecture that can test both single-port memory and dual-port memory using various test algorithms is proposed. In the FPMBIST, a new instruction set is developed to minimize the FPMBIST area overhead and to maximize the flexibility. In addition, FPMBIST includes a diagnostic scheme that can improve the yield by supporting three types of diagnostic methods for repair and diagnosis. The experiment results show that the proposed FPMBIST has small area overhead despite the fact that it supports various test algorithms, thus having high flexibility. [ABSTRACT FROM AUTHOR]

A field experiment investigated the evaluation, teaching, and application of two different approaches to automatic control in programmable logic controllers, in particular comparing the Unified Modeling Language (UML) to the classic procedural paradigm (IEC 61131-3). A total of 85 apprentices from a vocational school for production engineering with a specialization in mechatronics took part in the training and the experiment. This paper details the results of the training using both approaches, and the correlations found between the modeling and/or programming performance and cognitive abilities, interest, workload, expertise, and school grades. In general, the results show that students can be trained to carry out authentic programming tasks within one and a half days, even for beginners in programming. The data distinguish the two approaches. Function Block Diagram programming (IEC 61131-3) can be best predicted by the grade in mathematics, programming experience, and cognitive demand. For performance in UML class diagram and state chart (UML/CD+SC) modeling, the grade in mathematics plays an even more prominent role; this explains the greater variance in modeling performance in the UML group than in the 61131/Function Block Diagram group. With respect to other findings, the paper concludes that special problem-solving skills and skills for abstract thinking should be taught when teaching UML-based modeling approaches. [ABSTRACT FROM AUTHOR]

Abstract: Despite the many studies that have attempted to develop “friendly” methods for industrial controller programming, they are still programmed by conventional “trial-and-error” methods and in practice, there is little written documentation on these systems. The ideal solution is to use a computational environment that allows industrial engineers to implement the system using high-level language and that follows international standards. Accordingly, this paper proposes a methodology to model and validate control programs for manufacturing systems that include sequential, parallel and timed operations, using a formalism based on Statecharts, denominated Basic Statechart (BSC). To improve the formal aspects of the original Statecharts, we introduce the semantic of the BSC using only characteristics relevant to the industrial area. We also present an algorithm that translates the control model described in BSC into Ladder diagrams, thereby enabling tests with actual PLCs. Finally, one typical example of application in the manufacturing area is discussed as case study to illustrate the proposed methodology. [Copyright &y& Elsevier]

The article deals with the integration of dynamic link libraries in machine motion into the programmable logic controllers (PLC). This capability is achieved with the development of library modules for the implementation of projects and for giving commands to the servo-mechanisms. Two servo-mechanisms are shown in print marker synchronization which moves either by a transporting device or a tool. A block diagram of the complex functionality of the synchronized print marker is provided.

In this study, a reactive power compensation system has been implemented using a programmable logic controller (PLC). The four induction motors, which are used as reactive power consumers, are run or stopped by PLC in the power system. Thus the power system containing more than one reactive power consumer has been prepared. The current and the voltage of the power system are measured and then processed in the PLC to calculate the power factor of the system. The power factor calculation procedure is a novel algorithm developed by the authors. The required reactive power is provided by switching the capacitor groups automatically using the developed software. In addition, the developed system can protect the induction motors against some possible problems, such as overcurrent, high/low voltage, and phase sequence error. Owing to the improved computer interface, starting and stopping of the motors and monitoring of the parameters of the power system could be easily achieved using the computer. Furthermore, it has been shown that the proposed system is very flexible and expandable for different applications. In the study the most important disadvantage is that the grid current waveform is destroyed after reactive power compensation since the motors used as load do not draw a complete sinusoidal current from the grid. [ABSTRACT FROM AUTHOR]

new design of feed support system for Five hundred meter Aperture Spherical Telescope (FAST) is proposed in this paper. According to the similarity theory, a 1:15 scale model of feed support system has been built to make systemic research on the feasibility of the system. Then the control system and hardware structure of the feed support system are illustrated. A complete astronomical observation track is run by the scale model and the experiments results demonstrate that the new feed support system can satisfy the observation accuracy requirement of FAST. [ABSTRACT FROM AUTHOR]

Sequential function charts (SFCs) are among the standard languages for programmable logic controllers (PLCs) ubiquitous in automated manufacturing and production systems. While SFCs are quite user friendly to developers, it is not easy to guarantee the correctness of safety-critical SFC programs. Thus, methods and tools for verifying the correctness of SFC programs are highly desirable. Here we introduce a transformation technique that converts a significant subset of an SFC to a time Petri net (TPN). Thanks to a large body of literature and mature tools that can analyze TPNs, our technique will bridge the gap between a user-friendly manufacturing control programming tool, the SFC, and powerful analysis tools for TPNs. [ABSTRACT FROM PUBLISHER]

This paper provides a comprehensive overview of long-term R&D activities of the Rockwell Automation (RA) company in the field of holonic and agent-based manufacturing control systems. It presents a coherent framework of methodologies for designing agent-based control systems, tools that support implementation and validation of them, and agent applications that were developed for various industrial systems. The common attribute is the integration of novel techniques, such as multiagent systems or semantics with the current “old-fashioned” automation architectures represented mainly by programmable logic controllers. Retaining the ability of the control system to meet the strict real-time constraints and concurrently raise its intelligence has always been of highest importance. The paper does not focus merely on RA's work, but discusses all its aspects in a context of other existing works in this area. [ABSTRACT FROM PUBLISHER]

A method for restart after an error in a manufacturing system is introduced. The method is able to restart systems even after nonforeseen errors that cannot be planned for, and the online part of the restart method does not require use of more powerful computers than a standard Programmable Logic Controller. It is shown what properties the control function must have to ensure that there is at least one restart state for each controller state. Sufficient conditions to guarantee the possibility to restart a system regardless of where an error occurs are given, along with indications on how the system could otherwise be rebuilt to be restartable. [ABSTRACT FROM AUTHOR]

Abstract: After successful achieving first plasma, Korea Superconducting Tokamak Advanced Research (KSTAR) is now preparing second operation that includes power supplies with full power operation and more diagnostic systems. During first campaign the Experimental Physics and Industrial Control System (EPICS) was adopted as a control middleware of the KSTAR control system showed stable and reliable results and did not reveal any significant system failures. The EPICS based plant control system is used for data acquisition, data archiving and data visualization and is interfaced with Central Control System (CCS). A plant control system requires an EPICS Input Output Controller (IOC) and its own DAQ system. During the first operation the EPICS based control systems were mainly used slow data acquisition at a rate less than 10Hz. The hardware platforms were Programmable Logic Controller (PLC) and PCI eXtensions for Instrumentation (PXI). In this paper we will describe following items: the details of control function, implementation of each plant control system, operation results and analysis, focusing on the Tokamak Monitoring System (TMS), the Vacuum Monitoring System (VMS), the Current Lead System (CLS), the Helium Distribution System (HDS), and the Heating Systems. [ABSTRACT FROM AUTHOR]

In this study, the design of a programmable infinite impulse response switched current (SI) filter is presented. The characteristics of the filter are fully programmable by simply varying the values of out-of-chip DC current sources. The programmable switched current filter mainly consists of SI delay cells and SI multipliers. A high-performance class AB grounded gate SI memory cell is used as a basic building block. Spice simulation results are presented to show the functionality of the programmable filter. [ABSTRACT FROM AUTHOR]

Material handling in manufacturing systems is becoming easier as the automated machine technology is improved. Nowadays, most of the research aims at increasing the flexibility and improving the performance of the automatic guided vehicle (AGV). In this paper, designed and made AGV in the Industrial Control Laboratory in Royce Lab at the University of Manchester Institute of Science and Technology will be presented. For controlling the navigation of the AGV, a newly developed controller integrated fuzzy logic with programmable logic controller will be used. By using integrated fuzzy logic controller with programmable logic controller (IFLPLC), the flexibility of AGV will be increased and we achieved great advantages, which can be used in future. Since this AGV uses programmable logic controller and fuzzy logic controllers together, then it will be useful for factories which implement flexible manufacturing system (FMS). Online maintenance and sending the commands to other machines from AGV and so on are the advantages that can be used in FMS. The aim of this paper is to propose the practical example of IFLPLC. The designed AGV is able to reach the target. Further researches are required for collision avoidance and selecting the best way in FMS [ABSTRACT FROM AUTHOR]

The paper analyses two approaches to organize the control requirements in PLC programming and the PLC response time provided by these approaches. The first one, the output-oriented approach, uses switching tables in order to provide outputs equations. The second approach, the stateoriented approach, uses the state diagram which defines the control steps for the process operation. Each approach is illustrated by applying it to determine the Boolean equations required to meet specified control requirements for a given case study. It is shown that the output-oriented approach is recommended only in time-critical applications and in program memory critical systems, where delays affect the reliability and the performability of the control system. For all other applications the state-diagram approach is preferable.. [ABSTRACT FROM AUTHOR]

Abstract: A simple and convenient control system has been developed for the 150MeV proton FFAG accelerator complex at Research Reactor Institute, Kyoto University. This control system is designed as a distributed control scheme and developed with simple and versatile tools, such as PLCs, LabVIEW and an IP based network, expecting applications in small accelerators, which are often operated by non-specialists in computer programming or in control systems. The control system for the FFAG accelerator complex has actually been developed by non-specialists, and the developed control system was successfully used for commissioning the FFAG complex. [Copyright &y& Elsevier]

Abstract: Iterative feedback tuning (IFT) is applied to tune the cascade speed and position controller of a permanent magnet (PM) servo drive. Several variants of experimentally obtained criteria for the test bed are analyzed. The results of the IFT controller, which was easily implemented on a programmable logic controller (PLC), are compared with the results of three tuning schemes commonly used in the industry. Experimental tests on the PM motor with different types of load show that IFT performance in transient conditions is as good as or better than other methods. [Copyright &y& Elsevier]

Defect tolerance will be critical in any system with nanoscale feature sizes. This article examines some fundamental aspects of defect tolerance for a reconfigurable system based on Quantum-dot Cellular Automata (QCA). We analyze a novel, QCA-based, Programmable Logic Array (PLA) structure, develop an implementation independent fault model, and discuss how expected defects and faults might affect yield. Within this context, we introduce techniques for mapping Boolean logic functions to a defective QCA-based PLA. Simulation results show that our new mapping techniques can achieve higher yields than existing techniques. [ABSTRACT FROM AUTHOR]