Local Control System Research Articles

Дослідження стійкості та збіжності децентралізованої координації локальних систем управління розподіленими кібер-фізичними системами

The use of decentralized coordination of state control of distributed cyber-physical systems with continuous objects, in which, in addition to the physical interaction of the elements of a continuous object, there is information interaction of local coordinators as part of agents of a multi-agent system, leads to the formation of multi-loop control systems. The features of decentralized coordination control of such systems (nonlinearity of coordinators, mutual physical impact of the elements of the object, the presence of production costs of the accumulated resource, which determines the state of the elements, etc.) necessitate additional studies of the stability of the system and the convergence of the coordination process. The aim of the work is to study the conditions of stability and convergence of decentralized coordination of a distributed cyber-physical control system with a wave coordination method. A condition for the stability of such systems is obtained. The model of a system of two connected controllable elements and local control systems has been developed. The transfer function of the system is obtained using the method of equivalent transformations. It is shown that in the absence of coordination, such system is stable under the condition of attenuation under the propagation of influences on the elements of a continuous object. The stability and convergence of decentralized coordination of local control systems with the wave coordination method based on a simulation model is investigated using the example of three-element systems. The simulation model was created in the Scilab/Xcos system. As a result of the studies, it was shown that although the system is stable, the state of the object's elements coincides with the specified one, however, the duration of the coordination process significantly exceeds the duration of the transient processes of individual elements. Further research is supposed to be directed at the proof the hipotesis that the stability of the system independent of the number of controlled elements of a continuous object and studying the conditions for the stability of active systems (with an increase in the influence in the process of propagation).

Использование горячего изостатического прессования для изоляции радиоактивных отходов

The paper summarizes the findings of a study focused on hot isostatic pressing (HIP) technique implemented by the Khlopin Radium institute. The equipment was designed and manufactured at the Kharkov’s Physics and Technology Institute. The installation provided a pressure of up to 400 NPa with the pressing temperature of up to 1250°C. The experiments were carried out on installations located in hot cells in the radiochemical department (Gatchina city). Samples of materials for HLW immobilization (titanate ceramics of the synroc type, stabilized cubic zirconia) and matrices for 129I immobilization based on copper iodide and metallic copper were obtained. The leaching rate from these samples of HLW elements (simulators) amounted to (0.5—1.5)·10–9 g/(cm2 ·day). Despite the high-performance characteristics of the materials obtained, some problems were revealed associated with the remote maintenance of equipment and the lack of industrial design analogues. Considering the experience gained, we believe that fairly simple equipment can be designed implying no complex systems and providing minimum preparatory operations. Joint efforts of technologists and designers will enable the automatization of equipment management and control through local control systems. Material loading and unloading operations can be robotized as well. Such technical solutions are expected to be in demand at industrial facilities for HLW final disposal (or when handling damaged fuel during the decommissioning of radiation and nuclear hazardous facilities).

Government Internal Control System and Local Government Administration Performance: Evidence from Indonesian Local Governments

This study investigates the effect of local government internal control systems on local government administration performance. We use secondary data from the Ministry of Internal Affairs, Financial and Development Supervisory Agency, Indonesian Statistics Bureau, and respective local government financial statements and websites. We generate a set of panel data from 508 local governments during 2017-2019 with 1524 observations analysed with panel data regression. We evidence that several local governments still have low and medium administration performance in 2017-2019 that has not met the expectation of the Ministry of Internal Affairs as stated in the strategic plan in 2015. Our analysis provides empirical evidence that control environment, risk assessment, and information and communication positively affect local government administration performance. Our result provides implications to the Financial and Development Supervisory Agency to continuously optimise internal control system development programs in Indonesian local governments and the Ministry of Internal Affairs to have higher enforcement of local government administration performance achievement.

The role of budget decision making in mediating trust, social ties, cultural context and local government performance

Indonesian Corruption Watch (ICW) research reveals that corruption in Indonesia is mostly carried out by civil servants. An audit report from the Indonesian Supreme Audit Institution also finds local government internal control systems' weaknesses, especially controlling budget execution. This phenomenon is inseparable from the budget actors' decision-making process when preparing a budget. Budget decision making is a crucial process. Budget actors use their preference to choose among priorities and put the programs and activities which they have chosen into the budget. Social exchange such as trust and social ties can restrain budget actor distortion when making a budget decision and improve local government performance. Cultural context, in this research, refers to high context, affects individual behavior, and may influence the budget decision-making process. The result shows that decision making mediates trust and context culture to local government performance. Trust also proven can improve local government performance. Social ties, on the other side, do not have an influence both on decision making and local government performance. When trust has been intertwined among members, social ties no longer have a role in social exchange. Trust is the strongest form of social relation. Trust in this research is also formed because of the figure. A figure holds an important role in high context culture. This research pointed out that decision making by considering social values can make the decision-making process better and even improve local government performance.

Production Process Automation for Construction of Monolithic Buildings and Structures

Article presents a scientific approach to creating a complex production process automation system for construction of monolithic buildings and structures (MBS). Specific features of systems with complex structure which present themselves in the way they function and by the interaction of local control systems within integrated system for production process automation were discovered. Justification is given to the structure of creation of local systems for automation of MBS construction processes and their functioning within interconnected complex control system. Model for optimal transportation of concrete mixture to the pouring site with sliding thermo-active formwork with hydraulic actuators is presented in the article. The model is integrated by parameters of physical and mechanical processes. Concept of production process automation for construction of MBS was outlined. The concept is implemented in accordance with specific operational and technological and IT support of integrated system for automated control. The greatest potential for increasing the rate of housing construction is possessed by the technology of monolithic housing construction. However, traditional methods of erecting monolithic structures are associated with increased labor intensity, a significant share of manual operations, and the lack of objective instrumental control of the quality of concrete work, which significantly affects the increase in the time and cost of construction. A radical solution to the problem of increasing the efficiency of monolithic housing construction technology is possible only through the integrated use of automation, robotization and microprocessor technology. A method and means have been developed for automating the processes of feeding, distributing, laying and compacting concrete mixture, which make it possible to fundamentally change not only the nature of the work of construction workers, but also its organization, productivity, quality and intellectual saturation. The technical requirements for the automated structures of switchgears are formulated, based on taking into account the specific technological conditions for the production of concrete works. A criterion is proposed and a methodology for choosing the optimal kinematic structure of an automated switchgear for the production of concrete works is developed. The problem of determining the geometric characteristics (the length of the links, the angles of rotation of the joints), the distribution booms for the given constructive and technological conditions of concreting has been solved.

Optimizing Energy Consumption and Occupants’ Comfort in Residential Buildings Using Local Control System Based on Occupants’ Behaviors

Optimizing Energy Consumption and Occupants’ Comfort in Residential Buildings Using Local Control System Based on Occupants’ Behaviors

Perfection of equipment and technology of steel ladles lining drying and heating to neutralize emissions of organic binders decomposition products

Technological operations of steel ladles lining drying and heating are accompanied by formation and emission of compounds, referred to the first and second category of danger. This is attributed mainly to the presence in the refractory’s composition phenol-formaldehyde tars and coal pitch as binders. Results of simulation of steel ladle lining heating operation presented. The filtration speed distribution of decomposition products in the lining material established. The main part of harmful substances from the lining is emitted in the process of its drying into internal working space of the ladle. Less than 10% of the total amount of pollution substances goes out through the external evaporating openings in the ladle armor. It was shown, that within near 90% of drying and heating time, the temperature in the ladle does not exceed level of 800 °С, which is not enough for harmful substances afterburning. Reasonability of afterburning of the formed harmful emissions justified as a separate technological element of the facility of ladles drying. For the afterburning, not expensive materials should be used, having catalyst properties and developed surface. Application of catalyst enables to decrease the minimum necessary temperature for oxidation of decomposition products down to 600-650 °С. Description of the facility, developed by Concern “Jet Technologies”, for ladles drying and heating with neutralization exhausted technological gases presented. The facility has an airtight shelter, in which a ladle with new lining is placed. The shelter has a lifting cover, in which a gas-air burner is installed. The burner can operate with a high excess of air to provide minimal temperature of drying agent at early stages of drying. Inside the shelter a negative pressure is kept for active removal technological gases and prevention of penetrating them into the working zone of the shop. The power of the burner is controlled by the temperature, measured by a thermo-converter in the cover. Out of the shelter the technological gases are directed to a thermocatalyst reactor (TCR). The TCR has another burner for additional heating of gases leaving the ladle, to the afterburning temperature. Power control is made also based on the measured temperature. After completion of emitting binder decomposition products, the TCR is switched off. After neutralization in the TCR, the technological gases are emitted into atmosphere through a smoke stack. The facility operation control is made by a local control system, based on an industrial logic controller. At the EAF-based plant “NLMK-Kaluga”, the ladles with phenol-based binder lining are successfully dried for many years already at a facility described in the paper, providing an ecological safety of the emissions.

Hydraulic optimisation of multiple flow control locations for the design of local real time control systems

ABSTRACT Local real-time control (RTC) represents a potentially cost-effective solution for stormwater management in urban drainage systems. Existing methodologies to select the location of flow control devices (FCDs) are limited to single gate systems and are based on analysis of activated storage volume capacity, without considering hydrodynamic processes or rainfall characteristics. In this paper, a new genetic algorithm (GA)–based methodology is developed to determine the optimal location of multiple FCDs in urban drainage networks, when assessing RTC performance through hydraulic analysis. The methodology is tested on a case study network, where a high number of possible FCD location arrangements are tested and compared, and the RTC effectiveness in reducing combined sewer overflows has been evaluated over a range of design storm events. Results demonstrate the capability of the proposed method in selecting robust FCD placement strategies, for example when designing local RTC systems to meet specific performance criteria.

Ultra-broadband local active noise control with remote acoustic sensing

One enduring challenge for controlling high frequency sound in local active noise control (ANC) systems is to obtain the acoustic signal at the specific location to be controlled. In some applications such as in ANC headrest systems, it is not practical to install error microphones in a person’s ears to provide the user a quiet or optimally acoustically controlled environment. Many virtual error sensing approaches have been proposed to estimate the acoustic signal remotely with the current state-of-the-art method using an array of four microphones and a head tracking system to yield sound reduction up to 1 kHz for a single sound source. In the work reported in this paper, a novel approach of incorporating remote acoustic sensing using a laser Doppler vibrometer into an ANC headrest system is investigated. In this “virtual ANC headphone” system, a lightweight retro-reflective membrane pick-up is mounted in each synthetic ear of a head and torso simulator to determine the sound in the ear in real-time with minimal invasiveness. The membrane design and the effects of its location on the system performance are explored, the noise spectra in the ears without and with ANC for a variety of relevant primary sound fields are reported, and the performance of the system during head movements is demonstrated. The test results show that at least 10 dB sound attenuation can be realised in the ears over an extended frequency range (from 500 Hz to 6 kHz) under a complex sound field and for several common types of synthesised environmental noise, even in the presence of head motion.

THE DEBT OF MUNICIPALITIES IN BULGARIA - THREAT OR OPPORTUNITY

In times of high liquidity in the credit markets and low interest rates, debt financing is an attractive opportunity both for expanding the municipal investment program and for meeting short-term temporary current needs. The purpose of this article is to review the debt financing of local authorities in Bulgaria for the period 2008 -2018, to assess whether the macroeconomic risk is currently present on municipal debt in Bulgaria, to analyze the potential risks of rising local debt levels. The change in the municipal debt of EU countries is presented, the examples of the implementation of local debt control and monitoring systems are given.

Comparative analysis of adaptive systems for automatic stabilization of the water level in the drum boiler

The comparative analysis of two kinds of adaptive systems for automatically maintaining the water level in the drum of large boilers of thermal power plants is carried out with the stabilization of their dynamic characteristics in the face of changing parameters of the control object. The analysis is carried out with the purpose of determining the most effective adaptation method and development on its basis, a typical local adaptive automatic control system for various paths of energy steam boilers. As a control object, for example, the drum boiler feed circuit is selected because the process of changing the water level in the drum due to a violation of the material balance between water supply and water consumption is the most responsible and complicated due to the astatic type of its transfer function. Both systems are unidentified and contain a reference model in the adaptation loop. The advantages and disadvantages of the analyzed systems and the prospects for the application of adaptation methods laid down based on their construction are established.

Design Method of Local Control System Centred on IOT Technology

For realizing the comprehensive monitoring of the ships and warships, the internet of things (i.e., IOT) technology is adopted by the local control system, which consists of the sensing layer, the transmission layer and the whole ship monitoring layer. First, state data is collected by various high-precision sensors of the sensing layer, and then transmitted to the entire ship monitoring layer via the entire ship transport layer based on Modbus TCP/IP design. The local control system is based on the STM32 MCU. It integrates functions such as signal acquisition, Ethernet, CAN bus communication, interactive display, and fault diagnosis. The effectiveness, practicability and flexibility of the on-site control system were verified by a ship propulsion experimental system. The on-site results can provide and verify big data technical support for different regions, regulatory agencies and equipment maintenance of the whole ship.

Superposition of the uncertainties in acoustic responses and the robust design of active control systems.

The use of virtual sensing allows the frequency range of a local active noise control system located close to a listener's ears to be extended beyond what is possible when only controlling from remote physical sensors, particularly if head tracking is also used to determine the position of the virtual sensors. As the frequency range is extended, however, the uncertainties in the acoustic responses become more significant, and the design of multichannel adaptive controllers that are robustly stable to these uncertainties becomes more important. In order to fully characterise the uncertainties, a very large number of measurements would, in principle, need to be taken, due to the combination of all the possible changes in the acoustic environment. For uncertainties due to the simultaneous change in position of several objects within the acoustic environment, however, it is shown that the uncertainties can be accurately predicted by the superposition of these uncertainties, due to the change in position of the objects individually. This allows the uncertainty that is due to the change in position of a number of objects to be rapidly evaluated from a limited number of experiments and considerably simplifies the controller design process, which is illustrated here for an active headrest system using two different virtual sensing techniques.

Parametric synthesis of the controller by metaheuristic algorithm in the SimInTech environment

Efficiency and quality of operation of local automatic control systems as part of an autonomous object is mainly determined by the regulator in their composition and the used control law, for the synthesis of which is necessary to use modern computer-aided design systems. The article presents the results of the application of genetic algorithm as a method of parametric synthesis of the PID-controller implemented in the SimInTech visual dynamic modeling environment, which currently is used by enterprises in the rocket and space sectors of Russian Federation. Object of research is the dynamic negative feedback system on the example of the automatic angular position of artificial satellite control system. The functional scheme and the simplified mathematical model of the system in the form of the transfer functions of its links are presented. The computer model of the system as well as a process of synthesis of the controller are implemented as a package of projects, based on standard blocks and submodels SimInTech. Projects interact using a common signal base, which provides information exchange between projects, making the system model flexible and versatile. An interactive computing environment for programming language Python, Jupyter Notebook, is used as a third-party software. The organization of interaction between SimInTech and Jupyter Notebook is described, scripts of programs for its implementation are presented.

Development of intelligent algorithms for the continuous diagnostics and condition monitoring subsystem of the equipment as part of the process control system of a stainless steel pipe production enterprise

This article describes the process of development and implementation of an integrated APCS and continuous diagnostics and equipment condition monitoring subsystems using intelligent machine-learning-based algorithms for a stainless steel pipe manufacturing enterprise with combining local automatic control systems into a single information technology the system. Briefly, the author describes the technological equipment and the production cycle, its features, as well as its change as a result of the implementation of APCS. The software tools and their structure, the interaction of elements in the system, the main tasks solved with APCS and their impact on the quality of finished products are described. A feasibility study and justification of the application of PCS for this production are carried out.

A New Robust Energy Management and Control Strategy for a Hybrid Microgrid System Based on Green Energy

The recent few years have seen renewable energy becoming immensely popular. Renewable energy generation capacity has risen in both standalone and grid-connected systems. The chief reason is the ability to produce clean energy, which is both environmentally friendly and cost effective. This paper presents a new control algorithm along with a flexible energy management system to minimize the cost of operating a hybrid microgrid. The microgrid comprises fuel cells, photovoltaic cells, super capacitors, and other energy storage systems. There are three stages in the control system: an energy management system, supervisory control, and local control. The energy management system allows the control system to create an optimal day-ahead power flow schedule between the hybrid microgrid components, loads, batteries, and the electrical grid by using inputs from economic analysis. The discrepancy between the scheduled power and the real power delivered by the hybrid microgrid is adjusted for by the supervisory control stage. Additionally, this paper provides a design for the local control system to manage local power, DC voltage, and current in the hybrid microgrid. The operation strategy of energy storage systems is proposed to solve the power changes from photovoltaics and houses load fluctuations locally, instead of reflecting those disturbances to the utility grid. Furthermore, the energy storage systems energy management scheme will help to achieve the peak reduction of the houses’ daily electrical load demand. Also, the control of the studied hybrid microgrid is designed as a method to improve hybrid microgrid resilience and incorporate renewable power generation and storage into the grid. The simulation results verified the effectiveness and feasibility of the introduced strategy and the capability of proposed controller for a hybrid microgrid operating in different modes. The results showed that (1) energy management and energy interchange were effective and contributed to cost reductions, CO2 mitigation, and reduction of primary energy consumption, and (2) the newly developed energy management system proved to provide more robust and high performance control than conventional energy management systems. Also, the results demonstrate the effectiveness of the proposed robust model for microgrid energy management.

Automatic control system for the technological process of chlorella cultivation

This article devoted to the implementation of mathematical models and algorithms in control problems of the chlorella cultivation process. The article gives us expanded concepts about the construction of the control functional – algorithmic structure, as well as the automation of various microbiological processes and productions, which based on modern computing devices, creation of a full-fledged complex for the task of chlorella mass cultivation process.When building the control system, problems are solved: collection and primary processing of information, prediction of technological processes progress, optimization of mode parameters, process control.Within the framework of these main tasks solutions have been found, which make it possible to facilitate the operator-technologist operational control or to implement reasonable management decisions depending on different production situations. For the considered class of objects, in particular the technological process of microalgae cultivation, the task of synthesis of control systems is to maintain the technological process at an optimal level that meets the technological and ecological standards of production.One of the necessary conditions for the optimal conduct of the process of cultivation of microorganisms is automatic control of the content and composition of nutrients at the entrance, as well as control of the output indicators of the process.The following technical tasks are also required to implement the management systems:- Improvement of local control and control systems (pH, T, light.);- Nutrient composition control, continuous medium circulation.Periodicity of control tasks solution is established depending on process features, control object, process introduction mode, as well as the availability of a set of hardware.As a result of the implementation of the proposed control system, the maximum ratio of chlorella concentration to its average value decreased by 23.8%.Thus, the control system of the chlorella cultivation process provides a timely prediction of the technological process and the formation of control actions using a computing device, which contributes to an increase in the productivity of the cultivator by 8-12%.Based on the theoretical and experimental studies performed as part of this work, the following main results were obtained:1. Based on the developed models and algorithms, a functional-algorithmic structure of a control system for the chlorella cultivation process is proposed, oriented towards solving the following problems: collecting and primary processing of information, predicting the progress of the technological process, optimizing operating parameters and controlling the course of the technological process.2. The implementation of the control system made it possible to increase the yield of chlorella from a unit of spent nutrients, to increase the productivity of the cultivator due to the strict maintenance of the optimal value of the residence time of the substrate particles in the apparatus.3. The results obtained make it possible to draw a conclusion about the adequacy of the constructed models for the real process, the correctness of the selected control actions and optimality criteria, as well as the efficiency and effectiveness of the developed algorithms for optimizing and controlling the technological process of chlorella production cultivation.

Consensus‐based operational framework for self‐healing in multi‐microgrid systems

Recently, microgrids (MGs) present a vital role in the transformation of the existing power networks to the smart grids. Connecting MGs to construct the multi-microgrid (MMG) system enhances the robustness of the system against disturbances and upgrades overall network performance. In this paper, the MMG, as a source of self-healing support to the distribution networks, is analysed extensively. In fact, the MMG strengthens the self-healing of the network by participating in the restoration of disturbed loads. In this study, an operational framework is proposed for the self-healing problem in radial interconnected MGs based on two-stage cyber communication network architecture. In the first stage, the local control system (LCS) within each MG, schedules the accessible resources according to the local power consumption target. In the second stage, a number of LCSs are communicated globally to perform self-healing action. The communication of LCSs is accomplished using a consensus algorithm. Nevertheless, when a fault takes place in MG and a line is eliminated, the healthy MGs, due to demand and supply information in the first stage, supply the on-outage loads as far as possible. To validate the effectiveness of the proposed framework, two benchmark distribution networks (the 33-bus and the 119-bus) are employed.

The wells fluking hydraulic system elements dinamics system analysis and modelling for the adaptive and robust control problems

The article analyzes the development of modern approaches for the effective solution of the problems of adaptive and robust control with the compensation of perturbations by the process of drilling of wells during their deepening and accordingly proves that this is a scientific and applied issue, needs proper development, as well as the introduction of new mathematical models of elements. which are the core of the automatic control system. The ways of solving the problem of adaptive and robust control with the standard mathematical model of linear stationary objects by output, which are of great theoretical and applied importance and have been the subject of research in recent years, are considered. The functional structure of the intelligent adaptive ground control system of technical facilities of the hydraulic well-flushing system is developed, which integrates methods of adaptive and robust control, where the adaptive part of the system in the conditions of uncertainty can change the algorithms of operation, structure and parameters of the controller due to additional devices the holes that allow you to adapt to changing working conditions in a timely manner, and the robust system guarantees the required system quality regardless of errors and min parameters of the system because it has a sensitivity remains stable, functioning in a wide range of uncertainty. For the terrestrial elements of the technical hydraulic system for flushing wells, which are considered as objects with concentrated parameters, a phenomenological model is developed, which is based on a holistic approach. The model is formed in the field of Laplace image in time and in dimensionless form as a system of differential equations at zero initial conditions, which accordingly allows to use this model to synthesize the transfer functions of the inverters of local automatic control systems. The methods of control of elements of technical hydraulic system of flushing of wells are offered, based on the use of the developed model and structure of the intelligent system with elements of robust and adaptive control.

Drug-attached magnetic nanoparticles: Locomotion control and in vivo biocompatibility

Magnetic nanoparticles (MNPs) are playing an increasingly important role in the biomedical fields such as the diagnosis, treatment and monitoring of various diseases. Due to the unique properties of MNPs, MNPs with functionalized non-toxic surface coatings can be used for drug delivery in combination with therapeutic drugs or chemical molecules. A novel type of drug-attached magnetic nanoparticle was presented, where insulin was bound to magnetic Fe3O4 nanoparticles (MNPs-Insulin). It was particularly proposed for the future in vivo control to realize the targeted locomotion. The properties of the MNPs-Insulin were characterized by Fourier-transform infrared spectra (FTIR), thermo gravimetric analysis (TGA) and vibrating sample magnetometer (VSM) analysis. The ability of magnetic control was tested in the local motion control system in vitro. The good biocompatibility was certificated by Hematoxylin-eosin staining (HE) on mouse.