Laying a basis for service systems in process control

Chapter 6 - Protecting Critical Infrastructure: Process Control and SCADA

An ideal combination of process control and operation planning can reduce system cost and maximize economic and environmental benefits. This research proposed an integrated simulation-based process control and operation planning (IS-PCOP) system by using neural networks, genetic algorithm, multistage principle, and Monte Carlo simulation. It could well link process control and operation planning by simultaneously adopting different time-scales in computation. The hourly process control strategy forwarded the results to the operation planning module where long-term arrangements could be further evaluated. The use of ANN modeling also played a key role in predicting the nonlinear behavior of complex processes. In addition, Monte Carlo simulation yielded a better insight on uncertainties, which may arise from a number of different sources. A case study on marine wastewater management was carried out to demonstrate the efficacy of the proposed approach. Six different treatment standards (i.e., 5, 10, 15, 20, 25, and 30 μg L?1) were examined over a 20-day period and the 20 μg L?1 standard appeared to be the most economic option with a mean net cost of $18 per day. As compared to the traditional operation planning without process control, the integrated approach achieved more economically competitive results. By addressing the uncertainties and expressing the results in probability distributions, the decision makers would have more confidence in making decisions on both short- and long-term operations. It was concluded that the combination of process control and operation planning could help meet the economic objectives and ensure timely completion of the tasks.

The synthesis of control systems for overall processes remains a challenge. Whilst a number of automated approaches have been explored academically, in practice systems are mainly synthesised using experience and intuition in conjunction with dynamic simulation software. An approach is presented in this paper for the systematic synthesis of overall process control systems which is simple, practical and appropriate for use at the undergraduate teaching level. Many potential problems can be identified and avoided in the synthesis of process control systems by ensuring that the control system can maintain a steady-state control of the overall mass, the mass of the individual components and, where necessary, multiple phases. Processes with recycles are vulnerable to process control problems when the overall mass balance of the system containing the recycle is not correctly managed. This can be overcome by self-regulation (perhaps involving process design changes) or by changing the structure of the control system. Achieving and maintaining the material balance are the main purposes of the majority of controllers in most chemical processes. Without robust delivery of material balance control, higher level control objectives (such as quality controls) are unlikely to be met reliably. This paper presents a step-wise approach to the synthesis of overall process control systems that avoids many potential problems by identifying which process parameters can be manipulated to achieve the intended process mass balance and designing the control structure accordingly.

Process and Production Control Package

Current process control systems are composed of a large number of components and subsystems operating at different layers of the control system architecture model (i.e. measurement and control devices, Distributed Control Systems, Advanced Process Control systems, and Manufacturing Execution Systems). The IMC-AESOP project aims at designing the next generation architecture of process automation systems. In order to ensure system scalability and modularity, the new architectural design follows the SOA (Service-Oriented Architecture) design principles. Moreover, the design assumes adoption of various technologies with the aim to enable the control systems to meet all functional and performance requirements. The CEP (Complex Event Processing) technology has been selected for being able to provide efficient asynchronous communication (within and across architecture layers) and the capability of temporal reasoning over large amounts of system-generated events. This paper describes the intermediate results of the IMC-AESOP project, outlining the architectural concepts related to the use of the SOA and CEP technologies in the context of advanced alarm management applications - alarm load shedding and state-based alarming.Keywordsnext generation DCS/SCADAsystem of systemsprocess monitoring and controlalarm managementdynamic alarmingstate-based alarmingalarm load sheddingsoftware-oriented architectureSOAcomplex event processingCEPIMC-AESOP project

A program for handling multiple phases of the design cycle in process control system design

The cost of shutting down a refinery, or an oil well, or even a digital pipeline can cost millions of dollars in revenue loss to any oil company, and with today's oil prices at their highest peak, this could be devastating to the economy of countries were oil revenue still represents up to 70% of their total GDP. Now imagine, if this was caused by unauthorized access or breach of security to the production operations- Process Control Systems ? Process Control Systems have always been an integral and crucial part of any Energy company's critical infrastructure. Over the years, they have evolved from stand-alone islands to interconnected networks that co-exist with corporate IT environments, introducing many security threats. For the past years, these systems were effectively isolated from sources of cyber threats external to their owners and operators. But today, growing demand in the industry driven by new business requirements and new advancement in technology to link both systems together has led to an increase need to secure process control systems in order to minimize their vulnerabilities to cyber threats. In response, Cisco Systems has developed and innovative solution called "Secure Architecture for Process Control". This solution is designed to address the risks inherent in modern process control systems while providing best of breed security solutions and delivering comprehensive asset protection and secure access to real-time information. This paper will examine the new security threats facing the most critical infrastructures in the Energy industry and it will address the following topics; What are the new business trends and drivers ? What are the new security threats ? How secure is your system ? Should you be worried ? What solutions are available today ? What new services can be introduced ?

Das funkenerosive Senken ist ein abbildendes Abtragsverfahren zur formgebenden Metallbearbeitung, das im wesentlichen auf der Ausnützung von elektrischen Feldeffekten zwischen ungleich gepolten Elektroden basiert. Der Abtrag wird durch Funkenüberschläge in Folge einer pulsförmigen Spannung zwischen der (meist positiv gepolten) Abbildungselektrode und dem auszuerodierenden Werkstück bewirkt. Werkstück und Werkzeugelektrode sind dabei durch einen sehr schmalen (5(µm-50µm) mit Dielektrikum gefüllten Spalt getrennt. Infolge Leitwertänderung des Dielektrikums durch Erwärmung in Verbindung mit einer Kontaminierung durch Abtragspartikel ändert sich die elektrisch wirksame Spaltweite praktisch von Funken zu Funken. Dies stellt für die Prozeßsteuerung im Hinblick auf Abtragsmaximierung und Abtragsgüte (Oberflächengüte und Abbildungsgenauigkeit) ein hochgradig nichtlineares und zeitkritisches Problem dar. Zur Beherrschung dieser Prozeßführungsaufgabe wurde eine hierarchisch kaskadierte Prozeßführung entwickelt, die auf sehr unterschiedliche Zeitkonstanten reagieren kann. Die integrierten Fuzzy-Bestandteile behandeln dabei die nichtlineare Prozeßcharakteristik. Die Aufgabenverteilung auf die einzelnen kaskadierten Stufen richtet sich dabei nach den zeitlichen und regelungstechnischen Anforderungen und nach der zu bewältigenden Datenmenge. Insgesamt wird eine Hochleistungs-Prozeßführung vorgestellt, die neben effizienter Datenerfassung und -Übertragung über einen Protokollierungsanteil verfügt, der es erlaubt, die Wirkungsweise der einzelnen Fuzzy-Komponenten genauestens zu untersuchen. Abschließend soll über eine eigens entwickelte Fuzzy-Hardware berichtet werden, die zu einer deutlichen Geschwindigkeitssteigerung in der Abarbeitung von Fuzzy-Algorithmen führt.

To realize visualization for Process Control Systems (PCS) in Life Science Automation (LSA), the authors developed a Control and Simulation System. As an intermediary, the system receives scheduling data of experiment workflow from the PCS via a TCP/IP socket. Based on these data, it drives the simulation software 3DCreate to realize the automated experiment simulation by calling its COM API and Python API. After simulation, the system sends simulation results back to the PCS via TCP/IP socket, and drives the PCS to begin its real automated experiment task when the scheduling processes are checked to be correct by the simulation result. The system integrates hardware, PCS and simulation software, and realizes a real-time virtual simulation for experiment workflow in LSA laboratories. It saves experiment cost and improves the efficiency in laboratory automation display.

Service systems are essential to the execution of business services. When designing a service system, it is important to consider its global architecture to enable optimisation of high-level decision-making. In this paper, based on the analysis of the similarities between software and service systems, a new concept, service architecture, is presented. Service architecture (SA) defines the high-level structure of a service system, including service elements and their co-production relationships. The design quality of SA has a strong effect on the quality of service. Based on the summarisation of various service systems, we present several typical service architectural styles that can be directly reused to facilitate the development of high quality and efficient service systems. These styles are classified into three types, creational, structural and behavioural, based on a set of distinct dimensions. Features, application scenarios, graphical topology and typical cases for each style are then briefly discussed. In addition, comparisons between these styles, especially regarding their non-functional features, are shown. The results of this paper will aid in the study of methodologies for service system development.

Research in automating the process level of machining operations has been conducted, in both academia and industry, over the past few decades. This work is motivated by a strong belief that research in this area will provide increased productivity, improved part quality, reduced costs, and relaxed machine design constraints. The basis for this belief is two-fold. First, machining process automation can be applied to both large batch production environments and small batch jobs. Second, process automation can autonomously tune machine parameters (feed, speed, depth of cut, etc.) on-line and off-line to substantially increase the machine tool’s performance in terms of part tolerances and surface finish, operation cycle time, etc. Process automation holds the promise of bridging the gap between product design and process planning, while reaching beyond the capability of a human operator. The success of manufacturing process automation hinges primarily on the effectiveness of the process monitoring and control systems. This paper discusses the evolution of machining process monitoring and control technologies and conducts an in-depth review of the state-of-the-art of these technologies over the past decade. The research in each area is highlighted with experimental and simulation examples. Open architecture software platforms that provide the means to implement process monitoring and control systems are also reviewed. The impact, industrial realization, and future trends of machining process monitoring and control technologies are also discussed.

The numerical modelling and process simulation for the fault diagnosis of rotary kiln incinerator were accomplished. In the numerical modelling, two models applied to the modelling within the kiln are the combustion chamber model including the mass and energy balance equations for two combustion chambers and 3D thermal model. The combustion chamber model predicts temperature within the kiln, flue gas composition, flux and heat of combustion. Using the combustion chamber model and 3D thermal model, the production-rules for the process simulation can be obtained through interrelation analysis between control and operation variables. The process simulation of the kiln is operated with the production-rules for automatic operation. The process simulation aims to provide fundamental solutions to the problems in incineration process by introducing an online expert control system to provide an integrity in process control and management. Knowledge-based expert control systems use symbolic logic and heuristic rules to find solutions for various types of problems. It was implemented to be a hybrid intelligent expert control system by mutually connecting with the process control systems which has the capability of process diagnosis, analysis and control.

Communication infrastructure in substations and control centres of Transmission System Operators should be designed in order to support variety of applications and users with different priorities and requirements. Communication requirements vary regarding capacity, maximum response times, availability, reliability and security. Up until a few years ago majority of process control systems communicated through serial links. Recent communication protocols (like IEC 61850) used in process control systems are based on Ethernet technology. The main goal of these protocols is to make most of Ethernet regarding accessibility and flexibility, while additionally trying to achieve high requirements on availability, robustness, response times and security in process control systems. Conceptual design described in this article encompasses optimised process control communication network in the substation, designed in order to support all existing and some of the future applications and users in substation. It defines equipment and infrastructure necessary for substation internal communication between applications and processes, as well as for substation to control/maintenance centres communication. In the suggested solution of process LAN changes that will be necessary in order to support Smart Grid were taken into account. Process control LAN will be fundamental in creating substation automation systems supporting power network of the future. The basis of process control network is Ethernet as it ensures interoperability and flexibility. Industrial Ethernet additionally provides robustness necessary for substation environment. This conceptual design of substation process LAN emphasis Ethernet over SDH and IPoSDH (attached figure). In substations modern lEDs communicate over TCP/IP, and that make them compatible with computer networks. Older generation of devices will be connected on Ethernet over serial servers. Process LAN physical dividing from other parts of communication infrastructure maximize security level what can be done through virtual networks (VLANs) which separate different users and provide reserved capacities for critical functions. Process LAN implementation is recommended during installation of brand new SA systems or during refurbishment/migration of old secondary systems to new technology based on IEC 61850. (4 pages)

Event-related control is considered in which process and related process control can be described by states and transitions that can be represented concisely by a Petri net (PN). Both process and related process control systems are event-related, causal, and concurrent and define a special type of PN using a few primitives that are assembled to form a net for which structural and dynamic invariants apply. The PNs can be used for a general approach to event-related process control in simulating, checking, debugging, and stating the quantitative deviations from the ideal solution for any given process control system. The technique can be applied to continuous or discrete processes, and provides formal checks at all development stages. It allows for components with nonideal behavior and yields numerical performance criteria. The invariants allow the PN to be structured in such a way that even complex process control systems become manageable. Examples are presented for the control tasks in an electrical substation.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Architectures and Techniques of Artificial Intelligence in Process Control