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Copyright of DYNA - Ingeniería e Industria is the property of Publicaciones Dyna SL and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents simplest fuzzy logic controller (SFLC) PLC's based implementation applied to the cascade control strategy. Level and flow control loops are important and widely used in the oil and manufacturing industries to ensure a quality product. The control is used to maintain the level of the liquid in the tank at the desired value by manipulating the liquid in the reservoir. Two fuzzy sets on each input variable, five fuzzy sets on the output variable, five linear control rules, algebraic product bounded AND/OR operator, Larsen product inference and Centre of Sums (CoS) defuzzification are the components of this simplest nonlinear fuzzy controller to be implemented. The proposed work deals with the real implementation of a simplest fuzzy logic cascade control strategy designed on SIMATIC S7-300 Plc based on ladder diagram (LD) programming. In this paper, we have presented the results of the experimental tests of the conventional PI control strategy as well as the simplest fuzzy PI implementation applied to a PUL-2/EV cascade control device. Experimental results using this simplest fuzzy PI controller with the setpoint error shown that the setpoint tracking rise time can be reduced by 30% and the disturbance rejection time is decreased at 7sec compared to the conventional PID-PLC based controller, and concluded by stressing the importance of this new controller implementation. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Dalian University of Technology / Dalian Ligong Daxue Xuebao is the property of Journal of Dalian University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The existing Programmable Logic Controller (PLC) based on microprocessors (μ p) or micro-controllers (μ c) are commonly used in the industry for various instrumentation and control applications. PLC exhibits limitations such as less flexibility, poor scanning time, slower speed, and degraded response for high-speed industrial applications due to its fixed hardware and serial execution mechanism. A new Field Programmable Gate Array (FPGA) based PLC multi-channel High Speed Counter (HSC) module has been proposed, enhancing performance and flexibility compared to the existing PLC-HSC module. The proposed FPGA-PLC-HSC module has a 2-phase 2-Input counter with resolutions of 1X, 2X, and 4X which improve performance in terms of accuracy for position speed, and direction measurement applications. The FPGA-PLC-HSC module is implemented with the feedback node method and the shift register method inside LabVIEW FPGA along with device utilization. The simulation results show that the FPGA-PLC-HSC module has faster scanning time, good linearity, better resolution, maximum supporting input frequency, and counting frequency. For experimental purposes, an optical encoder M110960 (E8P-512-118-S-D-M-B) with a signal conditioning circuit is connected to the NI-myRIO-1900 FPGA platform. The experimental results point out that the proposed FPGA-PLC-HSC module offers faster scanning time, better accuracy and linearity in 1X, 2X, and 4X resolution. [Display omitted] • FPGA-PLC-HSC module is proposed with high resolution, linearity, and flexibility. • It is used to enhance performance for speed, position, and direction measurement applications. • The reported accuracy is ± 0.2675%, ± 0.1689%, and ± 0.12% in 1X, 2X and 4X resolution, respectively. • Proposed module offers less scantime, fast speed, and cost-effectiveness solution. [ABSTRACT FROM AUTHOR]

The security of cyber–physical systems (CPS) presents new challenges stemming from computations that work primarily with live physics data. Although there is a body of previous research on detection of malware on CPS, more effective designs are needed to address limitations such mimicry attacks and other forms of evasive techniques. Relay algorithms in particular, such as differential and harmonic protection algorithms, are essential to protecting physical equipment such as power transformers from faults. Relay algorithms, though, are often disabled, altered, or otherwise suppressed by malware. In this paper, we first provide background on the main types of failures that may occur in an electrical power substation after relay algorithms are disabled by malware. We also provide some initial insights into malware methods that involve physics-informed data manipulations, which in turn may lead to power outages and physical damage to power transformers. We then describe the design of a watchdog algorithm that is continuously on the look out for anomalies in the execution time of relay algorithms along with their associated performance counters. We implemented the watchdog approach in Python, and evaluated it empirically on emulations of differential and harmonic protection algorithms on a computing machine. [ABSTRACT FROM AUTHOR]

Automation of industrial installations is an assembly of mechanical and electrical equipment that can generate logical commands, through a software program, in order to replace the manual orders made by human operators. At present, there are automation systems such as PLC, DCS (Distributed Control System), HMI (Operator Interface), SCADA (Data Control and Acquisition System), ANN (Artificial Neural Networks) and more. Siemens has integrated into the standard PLC with Ethernet communication interface, a web server able to reading the tags from it and displaying them on a customizable HTML page. This web page can be accessed from within the network where it is located and from the outside of the network, a VPN connection, from a web-browsing device, accessing via the IP address of the PLC. [ABSTRACT FROM AUTHOR]

Abstract Despite significant advances made on anomaly detection systems, few reports are found documenting their practical integration into the industrial realm. Furthermore, the literature reports a wide range of complex detection strategies, which may require hardware changes/updates in order to be supported by critical industrial equipment such as industrial controllers (e.g., Programmable Logic Controllers). To address these issues, this paper documents a systematic methodology for the practical integration of lightweight anomaly detection algorithms into industrial control applications. It shows that industrial controllers, and in particular the scheduling rate of user programs, are sensitive to network traffic-based disturbances. Therefore, the methodology embraces the task scheduling rates found in control applications, and their deviation from the "normal" behavior. It designs a "monitoring" task, and an innovative algorithm for detecting abnormal task scheduling rates by leveraging the cumulative sum model (CUSUM) and a regression strategy applied on a specific time interval. Essentially, the approach enhances the industrial controller with a "security module" that can trigger alerts to identify early cyber attacks. The approach is extensively analyzed in the context of two industrial controllers: a Phoenix Contact ILC 350-PN controller, and a Siemens SIMATIC S7-1200 Programmable controller. [ABSTRACT FROM AUTHOR]

The paper reports design and development of a PLC-based controller for pneumatic pressing machine, which performs the most critical operation in an engine bearing manufacturing plant. The paper firstly overviews the manufacturing process of engine bearing and then discusses the need of automating the pneumatic press. The proposed automation system involves (a) speed control by replacing the conventional method with a variable frequency drive (VFD), (b) feeder and pusher control using PLC, (c) fault detection and safety measures, (d) and PLC-based sequential control of all the processes carried out on pneumatic press. The control system is based on MicroLogix-1000 PLC from Allen Bradley and the ladder logic program for it has been written on RSlogix-500. For the evaluation of the proposed control system, the PLC program was emulated on RSLogix Emulate-500 and the operations of the pneumatic press were simulated on FluidSIM-P. The results of simulation validate the design of PLC-based controller in general and digital input-output connections of the PLC and PLC program in particular. [ABSTRACT FROM AUTHOR]

In this paper, a virtual PLC environment aiming at assisting automation teaching, learning and e-learning is proposed and discussed. The main contributions are a virtual PLC environment propped on a local and remote applications, along with the comparison of two teaching and learning methodologies, one local, while the other offers a remote interaction with the system. The proposed framework fits in the emerging technologies on the Internet of Everything, having the potential of promoting the integration and communication of virtual and real systems. [ABSTRACT FROM AUTHOR]

Due to the growing size and complexity of the PLC (Programmable Logic Controller) programs used for controlling the industrial processes, there is an increasing need for an approach that can help the users to understand the control logics of the PLC programs easily, and can assist them to analyze the programming errors effectively. In this paper, we propose an approach that takes the source code file of PLC program as the input; and transforms it into a hierarchical-structured XML (extensible markup language) file. The XML file format is based on the PLC output instructions and their corresponding conditions. It helps the users to identify the actual cause of a programming error quickly. In addition, a novel technique is applied that decomposes the PLC program into several smaller and modular sub-logic blocks. This makes the control logic simpler and easier to follow. An additional software application has also been developed for state-based graphical visualization of the XML file. [ABSTRACT FROM AUTHOR]

In order to design a vertical lifting three-dimensional garage control system, and to achieve the mechanical three-dimensional garage of the university automatic operation, the photoelectric sensors, hall pressure sensors and programmable logic controller (PLC) are used. The results show that the threedimensional garage control system can run safely and reliably, and each sensor can perform fault self-diagnosis and carry out certain treatment on the fault. In conclusion, the three-dimensional garage control system designed is feasible, and it can get wide extension and application. [ABSTRACT FROM AUTHOR]

This study designs a programmable logic controller (PLC) and wireless touch control technique for use in mechatronics learning. Its purpose is to provide a laboratory platform for students of engineering and technology to expenment with the design of wireless touch control technique. The principles of instructional systems design were implemented in the development of the learning module. This innovative two-position oscillating learning system elucidates the principles, function and application of mechatronics and wireless touch control technique. Thirty-eight students and eight domain experts answered an anonymous questionnaire. The domain experts were university professors and/or researchers with an average of more than five years of experience in mechatronics. An encouraging preliminary assessment of the proposed system demonstrated the accuracy of the embedded knowledge as well as the effectiveness. [ABSTRACT FROM AUTHOR]

Liquid fuels like furnace oil are predominantly used in industrial application. Viscosity is the most important characteristic in the storage and use of fuel oil. Viscosity influences the degree of pre-heat required for handling, storage and satisfactory atomization. If the oil is too viscous, it may become difficult to pump to light the burner as well as tough to operate which causes poor atomization. Therefore pre-heating is necessary for proper atomization as it may result in the formation of carbon deposits on the burner walls. This work presents the development of a modular temperature control system for furnace feed oil and implemented using a modern high performance PLC. [ABSTRACT FROM AUTHOR]

The issue of organizing distributed monitoring and control devices, both from a physical topology point of view as well as from a logical connectivity perspective, represents a perpetual research topic in the field of applied Electric Engineering. The complexity of the issue is due to the multitude of equipment and devices coexisting on the market and due to their various interconnectivity possibilities. Interconnecting such devices, equipped with various communication interfaces and protocols, is achieved by implementing unified data transfer platforms, such as the OPC (Object Linking and Embedding for Process Control) platform. [ABSTRACT FROM AUTHOR]

Abstract: Simple predictive control (MPC) algorithms produce a feed-forward compensator that may be a suboptimal choice. This paper gives some insights into this issue and simple means of modifying the feed-forward to produce a more systematic and optimal design. In particular, it is shown that the optimum procedure depends upon the underlying loop tuning and also that there are, as yet under utilised, potential benefits with regard to constraint handling procedures, which helps to improve the computational efficiency of the online controller implementation. A laboratory test in a programmable logic controller (PLC) was carried out to demonstrate the code on real hardware and the effectiveness of the solution. [Copyright &y& Elsevier]

At the time being knowledge-based systems are used in almost all life aspects. The main reason for trying to use knowledge-based systems in real-time control is to reduce cognitive load on users (overload), their application proving to be important when conventional techniques have failed or are not sufficiently effective [1]. The development of automated diagnosis techniques and systems can help also to minimize downtime and maintain efficient output. This paper presents some issues of applying knowledge-based systems to real-time control systems. It describes and analyzes the main issues concerning the real-time domain and provides possible solutions, such as a set of requirements that a real-time knowledge-based system must satisfy. The paper proposes a possible architecture for applying knowledge-based techniques in real-time control systems. Finally, a way of employing knowledge-based techniques for extending the existing automatic control and monitoring system for the geothermal plant from the University of Oradea is presented. [ABSTRACT FROM AUTHOR]

Abstract: This paper makes two key contributions. First, it tackles the issue of the availability of constrained predictive control for low-level control loops. Hence, it describes how the constrained control algorithm is embedded in an industrial programmable logic controller (PLC) using the IEC 61131-3 programming standard. Second, there is a definition and implementation of a novel auto-tuned predictive controller; the key novelty is that the modelling is based on relatively crude but pragmatic plant information. Laboratory experiment tests were carried out in two bench-scale laboratory systems to prove the effectiveness of the combined algorithm and hardware solution. For completeness, the results are compared with a commercial proportional–integral–derivative (PID) controller (also embedded in the PLC) using the most up to date auto-tuning rules. [Copyright &y& Elsevier]

Model checking is often applied to verify safety-critical software implemented in programmable logic controller (PLC) language such as a function block diagram (FBD). Counter-examples generated by a model checker are often too lengthy and complex to analyze. This paper describes the FBDVerifier which allows domain experts to perform automated model checking and intuitive visual analysis of counter-examples without having to know technical details on temporal logic or the model checker. Once the FBD program is automatically translated into a semantically equivalent Verilog model and model checking is performed using SMV, users can enter various expressions to investigate why verification of certain properties failed. When applied to FBD programs implementing a shutdown system for a nuclear power plant, domain engineers were able to perform effective FBD verification and detect logical errors in the FBD design. [ABSTRACT FROM AUTHOR]

The paper presents some selected hardware solutions for the PLC dual processor bit-byte CPUs, which are oriented at optimised data exchange between the CPU processors. The optimisation aims at maximum utilisation of capabilities of the two-processor architecture of the CPU. The key point is preserving high speed of instruction processing by the bit-processor, and high functionality of the byte-processor. The structure should enable the processors to work in concurrent mode as far as it is possible, and minimise the situations, when one processor has to wait for the other. [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]

An attempt has been made to design a jute bag making machine in which all operations, like fabric cutting, hemming, mid-folding and herackle stitching, are carried out automatically in a single setup to produce parallel type jute bags of industrial standards. The salient design features of indigenously developed first prototype of an automatic jute bag making machine have been described. The proposed machine comprises four major units, like fabric cutting and conveying unit, simultaneous mouth edge folding and stitching unit, mid folding and material guidance unit. and simultaneous parallel side stitching unit. The motor drives, sensors and actuators are synchronized and automated by programmable logic controller. The proposed machine can produce bags of uniform quality with mouth edge folded, hemmed and parallel side stitched in one single integrated setup at higher productivity compared to present manual system. [ABSTRACT FROM AUTHOR]

Motivation and creativity are ones of the primary educational objectives, quite volatile by nature, difficult to understand and theorise. There are many studies treating creativity and motivation from different points of view and philosophical background. With respect to their interpretation of creativity, they could be classified into two major groups: considering creativity as a unique, sensitive phenomenon or as a quantitative entity of Education Theory respectively. The former approach is guiding the proposed study. This paper is based on the reports and research results of The Third International Workshop "Developing Creativity and Broad Mental Outlook in the Computer Age -- CBMO-2006" in conjunction with the 10th Conference of International Society for the Study of European Ideas -- ISSEI 2006, organized by the University of Malta, 24-29 July, 2006. [ABSTRACT FROM AUTHOR]

A new approach for process control in polyester manufacturing plants is presented, which is based on the distributed control system and simulation, enabling a high degree of automation. The technology seems to be stable process with operational ease providing protection against misguidance and wastage. Although a high initial investment is called for nonetheless high investments can be recovered in just three years of installing this technologically superior and economically viable control system. [ABSTRACT FROM AUTHOR]

This paper discusses the object-oriented software design for an automatic blending system. By combining the advantages of a programmable logic controller (PLC) and an industrial control PC (ICPC), an automatic blending control system is developed for a chemical plant. The system structure and multithread-based communication approach are first presented in this paper. The overall software design issues, such as system requirements and functionalities, are then discussed in detail. Furthermore, by replacing the conventional dynamic link library (DLL) with virtual X device drivers (VxD's), a practical and cost-effective solution is provided to improve the robustness of the Windows platform-based automatic blending system in small- and medium-sized plants. [ABSTRACT FROM AUTHOR]

This paper presents a variant of battery analyser, application based on a programmable logic controller (PLC) that uses the current analog output module. The program allows the control of the charging and discharging current, the independent monitoring of the voltage on each battery cell and the calculation of its capacity. [ABSTRACT FROM AUTHOR]

A conical tank in which the diameter changes with the tank height, allows the use of feedback control used in complex nonlinear systems, such as adaptive control. This project modified an existing system of two interacting tanks by inserting a removable solid cone into one of the tanks. This modification created two new nonlinear configurations, one of which had a discontinuity. Optimal controller settings at different depths of liquid were found by minimizing the integral of the absolute error (IAE). These settings were used by an adaptive PID controller at a different settings, comparing the results to a conventional PID tuned to that setting. [ABSTRACT FROM AUTHOR]

This paper presents one way of operating a garage door by using a programmable logic controller (PLC), a Global System for Mobile (GSM) modem and a mobile phone as remote controller. [ABSTRACT FROM AUTHOR]

In recent years, attacks such as the Stuxnet malware have demonstrated that cyberattacks against control systems cause extensive damage. These attacks can result in physical damage to the networked systems under their control. In this paper, we discuss our approach for detecting such attacks by distinguishing between programs running on a programmable logic controller (PLC) without having to monitor communications. Using power signatures generated by an attached, high-frequency power measurement device, we can identify what a PLC is doing and when an attack may have altered what the PLC should be doing. To accomplish this, we generated labeled data for testing our methods and applied feature engineering techniques and machine learning models. The results demonstrate that Random Forests and Convolutional Neural Networks classify programs with up to 98% accuracy for major program differences and 84% accuracy for minor differences. Our results can be used for both online and offline applications. [ABSTRACT FROM AUTHOR]

Most SCADA devices have few built-in self-defence mechanisms, and tend to implicitly trust communications received over the network. Therefore, monitoring and forensic analysis of network traffic is a critical prerequisite for building an effective defense around SCADA units. In this work, we provide a comprehensive forensic analysis of network traffic generated by the PCCC(Programmable Controller Communication Commands) protocol and present a prototype tool capable of extracting both updates to programmable logic and crucial configuration information. The results of our analysis show that more than 30 files are transferred to/from the PLC when downloading/uploading a ladder logic program using RSLogix programming software including configuration and data files. Interestingly, when RSLogix compiles a ladder-logic program, it does not create any low-level representation of a ladder-logic file. However, the low-level ladder logic is present and can be extracted from the network traffic log using our prototype tool. The tool extracts SMTP configuration from the network log and parses it to obtain email addresses, username and password. The network log contains password in plain text. [ABSTRACT FROM AUTHOR]