Modeling of Process Control Systems in Omola

The application of fuzzy models in thermal power control systems is considered. The structure of a fuzzy system for a thermal object (boiler) is described. Results of the design and a schematic realization of boiler aggregate control systems are reported. Use of the suggested fuzzy models for control of the fuel-air relationship and boiler water level are described as examples.

The proper and comprehensive identification of systemlevel failure mode during risk assessment for space systems has difficulty due to the complexity of system-level interactions that involve multi-physics and dynamic phenomena. This study looks into system-level potential failure mode identification by using a system-level modeling and simulation-based approach to risk assessment for space systems. The proposed approach is based on utilization of the modeling language “Modelica”, an equation-based, objectoriented modeling language that allows acausal modeling for complex cyber-physical systems. The Modelica has an important modeling capability for system-level interactions that involve multi-physics phenomena. This paper discusses the technical feasibility and expected effect of this approach based on several trial results of the proposed approach. Furthermore, this paper presents several issues with this approach as future work subjects.

Uncertainty is an inherent characteristic of actual control systems since their parameters are not fixed and may change based on external factors. The behaviour and performance of control systems can be strongly impacted by these unknown characteristics. Variability in the environment, ageing of core components, and manufacturing tolerances are some of the factors that contribute to this uncertainty and pose an unknown risk to control systems. As a result, real control systems' intrinsic parameter indeterminacy may have an impact on how well they operate. Real-life scenarios are often ambiguous and complex, posing challenges for decision-makers to articulate their opinions. Neutrosophic sets are employed in such contexts to handle indeterminacy effectively. Neutrosophic theory suggests a variable interval based on truth, indeterminacy, and falsity, allowing for the expression of both determinate and indeterminate information. Nevertheless, neutrosophic sets have not yet been used in the modelling, analysis, and design of uncertain control systems with determinate parameters. To close this gap, a new neutrosophic design technique is established in this study by introducing single-valued neutrosophic systems. The suggested control design method is illustrated with a numerical example employing neutrosophic parameters.

This paper explores the use of Multi-Agent Systems (MAS) to model networked Command and Control (C2) systems to support the development of C2 military applications. The study focused on the modeling of systems capable of simulating and evaluating important characteristics of networked C2 systems. Therefore, the study covers the context and concepts for the Armed Forces’ battlefield operations under C2 literature, and the potential applications of MAS in networked C2. Remarkably, the paper highlights the study of three different MAS simulators, namely, NetLogo, Gama, and Repast, observing their ability to co-simulate networked C2 systems with Mininet Wi-Fi (the selected communication network emulator). The reasons for studying these simulators are discussed, along with the metrics to select the most suitable one for further developments. It also highlights the contributions these guidelines offer to researchers and practitioners in military C2 systems, especially those involved in integrating MAS simulators in networked setups.

In the simplest cases, P-, PI- and PID-controllers with rigid (unchanged) parameter settings are used to control technological processes. If the mathematical model of the control object contains unknown disturbing influences and parameters that change during the control process, then a digital control system with a learning model should be used. The tasks of control, analysis and modeling of various processes and systems are solved using their mathematical models. The choice of a model is dictated by the conditions of implementation and the requirement of adequacy. The problem of developing control algorithms under uncertainty occupies one of the central places in modern control theory. To solve the arising problems of structural and parametric identification, as a rule, methods, and algorithms of the theory of adaptive control systems are used. The application of the principles of adaptation allows to ensure high accuracy of modeling with a significant change in the dynamic properties of the system under study, to unify individual subsystems and their blocks; reduce the development and debugging time of the system. This article discusses the problem of studying a digital adaptive system for turning the blades of guide apparatus (GA) of an axial compressor of gas turbine engines (GTE). The aim of the study is to increase the efficiency of the control system for turning the blades of the GA using a digital adaptive system. The gas-dynamic stability of the GTE axial compressor under changes in external conditions and engine throttling is provided by air bypass and turning the blades of the first and last compressor stages. The statement of the problem of synthesis of the system of adaptive control of the rotation of the blades of the GA compressor of the gas turbine engine is carried out. A mathematical model of the ACS in the canonical form “model of the system in the state space” and an algorithm for turning the blades of the GA using an adaptive PI-controller have been developed. Simulation modeling of ACS was carried out using the Matlab / Simulink software package. When implementing an adaptive PI-controller, the pressure deviation downstream of the compressor stage from the required value is reduced to 0.4 %.

Regardless of the large number of Object-Oriented (OO) modeling languages currently being used in the Information Systems (IS) modeling process, unavailability of an OO modeling language that can be used in both the analysis and design phases disintegrates the two phases. The problem is, such disintegration can lead to a high level of missing information in the real world system from the analysis phase to the design phase. The approach of this study is to propose a framework to produce design phase models from analysis phase models using ontology based Unified Modeling Language (UML), thereby integrating the two phases. The results obtained from the porposed framework involve: a consructed language which can be used in generating the analysis phase scripts; and the development of script files based on the UML constructs at the analysis and design phases to automatically generate the UML scripts for those two phases. Since this study is a part of an ongoing research study, it can be concluded that, at the end of this study (1) both analysis and design phases would be able to integrate using a common OO modeling language (2) the manual work involved in the current analysis and design modeling would be reduced (3) the complexities and difficulties faced by the modelers (By modelers we mean the analysts and designers who are doing the analysis and design phase modeling) in using UML modeling tools would be reduced.

Although structural health monitoring (SHM) and control is continuously gaining importance, information about SHM and control systems, referred to as "monitoringrelated information", cannot be fully described on a well-defined, mathematical basis. Monitoring-related information, such as information about the embedded algorithms of sensor nodes deployed, about communication protocols, or about the overall SHM strategies implemented, can advantageously be used for SHM and control system optimization or for the documentation of the SHM and control. The study reported in this paper enables monitoring-related information to be described using building information modeling (BIM). The BIM-based approach builds upon the Industry Foundation Classes (IFC), an open BIM standard facilitating the interoperability of BIM models. As will be shown in this paper, the standardized IFC schema will be extended, facilitating BIM-based modeling of SHM and control systems in compliance with the IFC standard. Using the extended IFC schema, a prototype SHM and control system is designed, implemented, and validated on a laboratory test structure.

One of the topical areas of theoretical and experimental research is the analysis, modeling and synthesis of technical systems with probabilistic interactions of elements. The work is devoted to the development of simulation models for the study of one class of such systems - network management systems. As data transmission channels, such systems use industrial or public digital computer networks. The use of computer networks in control systems leads to new problems: random time delay in the transmission process, the likely loss of the data packet, the possibility of asynchronous operation of the elements of the system. Not taking these factors into account can lead to a loss of sustainability of the management system. To study these problems, it is proposed to use simulation models of appropriate control systems. In the work, simulation models for a digital control system without delay in the transmission channel, a network management system with a network communication channel between the sensor and the controller have been developed. In this case, cases are considered where the transmission time on the network channel does not exceed the quantization clock time and when the transmission time over the network channel may exceed the quantization clock time. For the cases considered, appropriate simulation models have been developed. When simulating a network management system in which the transmission time of a data packet over a network channel could exceed the time of a quantization clock, it was assumed that the sensor and the controller have an infinitely large buffer. For simplicity of modeling, it was assumed that if a data packet from a digital sensor is not transmitted in one clock cycle to the controller, it is placed in the sensor buffer. With the possible transfer of data over the channel, all packets from the sensor buffer are transferred to the controller buffer. It was assumed that the controller processes incoming data from the buffer sequentially – one packet per quantization cycle. To simulate such situations it was suggested to use the corresponding developed random processes. Simulation of the functioning of digital and network control systems was carried out in the Simulink environment of the Matlab system.

Object-oriented modeling has become the de-facto standard in the software development process during the last decades. A great deal of research in this area focuses on proposing modeling languages. In order to properly understand, and assess an object oriented modeling language, we believe that a set of criteria or requirements is needed. This paper presents a framework to investigate and compare graphical object oriented modeling languages. This framework is based on a requirement set for an ideal object-oriented modeling languages.

It is well known that one of the significant disadvantages of the development of modern technological processes is the use of aspects of thinking associated with the use of already used design positions. From a practical point of view, there is no single optimal solution for tillage in agriculture. The methodology for solving complex, multipolar problems of quality and efficiency of technology must take into account a significant number of factors and be presented in an accessible form for the response of the working bodies of tillage machines. Precision tillage has great potential. The result of tillage operations can be improved depending on the optimal solution of construction working bodies and technological parameters of cultivating, which, in addition, can be adapted to the tillage technology depending on the local agro-climatic conditions. The article presents the results of the synthesis of the system of adaptive control of soil cultivation by creating a complex technological system with modeling of the structural-matrix schemes and on-stream technological influences of working bodies of machines and external agro-climatic conditions on the agrophysical state of the soil. The research methods are methods of analysis of structural schemes of technological process control systems; system-analog modeling of tillage control systems; structural analysis and synthesis of technological changes in agrophysical indicators of soil tillage. The main results are the structural diagram of the on-stream adaptive control system of the tillage unit for the requirements of precise agriculture; matrix diagram of the imaging and generalized system of equations of on-stream adaptive control of working bodies of tillage machines; system-analog model of the machine-tractor unit with the adaptive control system of working bodies.

Dynamic modeling and simulation of a double-effect absorption heat pump

Creol is an object-oriented modeling language in which inherently concurrent objects exchange asynchronous method calls. The operational semantics of Creol is written in an actor-based style, formulated in rewriting logic. The operational semantics yields a language interpreter in the Maude system, which can be used to analyze models. Recently, Creol has been applied to the modeling of systems with radio communication, such as sensor systems. With radio communication, messages expire and, if sent simultaneously, they may collide in the air. In order to capture these and other properties of distributed systems, we extended Creol's operational semantics with a notion of time. We exploit the framework of a language interpreter to use a lightweight notion of time, in contrast to that needed for a general purpose specification language. This paper presents a timed extension of Creol, including the semantics and the implementation strategy, and discusses its properties using an extended example. The approach can be generalized to other concurrent object or actor-based systems.

. Recently, digital technologies and software packages as MATLAB and MATCAD are widely used for modeling and research of control systems. When analyzing and synthesizing the control system, ”manual” operations do not allow one to cover fully the systematic approach both from the constructive and computational points of view. The most widely used in practice and at the same time simplest control device is the linear PID controller. However, computer modeling and digital studies of this controller are not at the required level. This paper reveals some features of the functioning of a linear digital PID controller with three settings on a 2nd order object. Considering these assumptions, in the paper, the object modeled in the terms of output and state variables and the known theoretical parameters occurring in the ACS with a PID controller are more adequately confirmed. For the experiments, the Matlab/Simulink system with the ”Simulink Response Optimization/Signal Constraint” package was used. In order to facilitate access to the package, some important features of the algorithm for solving the control problem are revealed using a specific example.

The article is focused on the study of the principles of discrete-event control and methods of simulation modeling of automatic control systems of production processes. The capacity expansion and cost-saving require introduction of automation into different standard production processes. The production process of the mid-tech casting of workpieces of different forms is considered a controlled process. It is characterized by the complete and long physical process behavior during processing operations, as well as an overly risky maintenance environment. It is proved that a decline in the human factor influence on the production process causes the reduction of production operation downtime, as well as the decreased amount of waste and rejected products.

The KEKB project, constructing an asymmetric electron-positron collider for B physics in Japan, has officially approved and has started in 1994. The goal of the KEKB accelerator control system is to provide a powerful, flexible, and extendible control system for both accelerator physicists, who need beam information and are not so patient, and operators, who control all equipment. To achieve this goal on schedule, we decided to use standard technology where it is applicable. We have studied some existing control systems based on Standard Model of the modern accelerator control systems, such as EPICS or V-system, as a framework of the control system and have chosen the base of the control system according to this study. Another key issue in the KEKB accelerator control system is use of database management system for unified management of the information which the control system requires. Integration of control system with the modeling software, SAD, is also discussed.