Modern Control Systems Research Articles

Development of a Control System for a Technological Line for the Production of Products from Foamed Polysty

Purpose of research. When designing new and modernizing existing control systems for the polymer drawing process, an important role is played by solving the problems of creating mathematical or simulation models and synthesizing control algorithms that reduce the share of manual labor. The article provides an overview of approaches to the development and modeling of automated control systems for extrusion production lines for the production of polymer products. The possibility of developing and modeling a multidimensional control system for the process of stretching foamed polystyrene based on the Matlab mathematical analysis package is considered. The relevance of the research topic is related to the trend of growth in the consumption market and the implementation of management in the context of creating more complex forms of packaging from polymers.Methods. For the development of the control system and its analysis, the fundamentals of the theory of multidimensional systems in control problems, the theory of plastics processing, methods of computer simulation of control systems were applied.Results. The article presents an algorithm for controlling the molding process and its implementation in the Simulink environment. Graphs of changes in the pulling speed and winding speed, changes in the thickness and tension of the web over time are presented and analyzed. A scheme of process line automation based on the developed algorithm is presented.Conclusion. The results of testing the model show that the use of mathematical modeling of the control system for stretching the expanded polystyrene web is possible to solve the problem of increasing production efficiency on existing equipment, which will bring their characteristics closer to new production lines, leaving the mechanical part unchanged. The significance of the work is due to the fact that the use of modern control systems can improve the quality of manufactured products, reduce the consumption of raw materials. Materials and research methods can be applied in the development of projects for other installations, for example, in the production of an optical sheet.

Comparative analysis of switched reluctance motor control algorithms

Nowadays it has become possible to develop inexpensive modern control systems for nonlinear complexity electromechanical objects due to the development of microprocessor technology and power electronics. Switched reluctance electric machines are among these devices. It makes it possible to widely use such electric machines in various practical implementations, in particular, in traction drives, electric drives of oil and gas drilling rigs, and in other applications. The switched reluctance electric machine is a non-linear object, and its control methods require formalization and grouping. The manuscript considers the design and functional features of switched reluctance electrical machines. The main methods of controlling these electrical machine types are given. Comparative analysis of the most known methods is carried out. The main classical methods of switched reluctance electric machine control are considered, such as a relay current controller with a limitation, the method of controlling the turn on/off angles and controlling the DC link voltage. Transient responses in the electric drive system are demonstrated using the considered methods. It is shown that by adjusting the on/off angles, it is possible to reduce the torque oscillation coefficient. The identified features of the presented methods will make it possible to simplify and reduce the development time for an effective control system for switched reluctance electrical machines as well as to reduce the torque ripple.

Features of analysis and selection of microprocessors in modern control systems

The article discusses the results of a brief retrospective review of the current microprocessors in control systems and the main directions of their development. The main requirements and selection criteria presented at the stage of the microprocessor design process in modern control systems, classification and architectural features of microprocessors are described. In addition, the «pipeline» processing method for maximizing processor performance, features of the analysis and selection of microprocessors in modern control systems using various architectural solutions for the elimination of contradictions arising in it related to conflicts are studied. According to the «pipeline» principle, three main types of processor architecture (VLIW – Very Long Instruction Word) with superscalar and multiple computing devices working in parallel are defined - depending on data, management and structural conflicts. Therefore, their use in VLIW processors and the limitation of their application in the field of scientific research is justified, due to the fact that the source codes are transmitted in a «closed» form. The main advantage of superscalar microprocessors is the independence of program-executable codes from their structure and the possibility of their execution on any processor models. In addition, the features of the EPIC architecture are described, which combines the advantages of the two different architectural solutions considered.

Closed-Loop Control of Carbon Dioxide Concentration and Pressure Improves Response of Room Respiration Calorimeters

Large room calorimeters are capable of rapid measurements that are usually made in hoods or small rooms. We evaluated the performance gains of four calorimeters constructed with modern control systems, sample gas preparation and data processing. Calibration of the calorimeters and instruments was performed in place, with traceability to international standards. Performance was evaluated by infusion of N2-Co2 gas and 243 24-h studies of individuals. Our subjects included children weighing 20 kg and adults engaged in heavy exercise. Errors for 24-h infusion measurements (n = 23) were -0.34 ± 1.24% for oxygen consumption rate and 0.11 ± 0.98% for carbon dioxide production rate. Calorimeter 90% response times were 2 to 6 min over a range of oxygen consumption rates from 100 to >4000 mL/min. Closed-loop control of supply and exhaust air flows provided consistent 24-h mean CO2 levels (0.39 ± 0.015%) and pressures (13.2 ± 4.4 Pa). Room calorimeters operated with closed-loop control can be used for accurate measurement of energy expenditure rate dynamics for a wide range of individuals.

Fault Diagnosis for Momentum Wheels of Communication Satellite Based on Artificial Neural Network

With the advent of several fault detection techniques in modern control systems design, this paper adopted the Artificial Neural Network (ANN) Fault Detection scheme for the Fault Detection of the Attitude Control System for a Communication Satellite. In satellite applications, telemetry data can be very large, and ANN is best suited for network modeling involving large sets of data. The availability of real satellite data from Nigcomsat-1R communication satellite provided a practical platform to assess the fault detection algorithm. Results obtained showed a good correlation between raw satellite telemetry data and Neural Network model-generated results for subsequent fault detection. The fault detection models were able to detect faults, log them and provide a notification to enhance subsequent isolation and rectification. Momentum Wheel Speed and Torque were used to investigate the performance of the wheels while the Momentum Wheel Voltage and Current helped to monitor the wheel’s health state. A fault is detected if the absolute difference between original output (MW Torque) and the NN Torque output is greater than 0.012. With this, an accuracy of 100% and mean squared error of 9.8489e-6 were achieved.

Luenberger Observer-Based Speed Sensor Fault Detection: real time implementation to DC Motors

Fault Tolerant Control Systems (FTCS) have emerged as a critical area of study for enhancing the safety, reliability, and efficiency of modern control systems. The FTCS technique might be active or passive control in general. In this paper, the active control branch's Fault Detection and Diagnosis (FDD) is used to detect faults in DC motor speed sensors. FDD methodologies can be divided into two types based on the process and the type of data available: model-based methods and data-based methods. The proposed method here investigates the use of the Luenberger observer technique, which is part of the model-based approach. The selected method was implemented and experimentally evaluated. This observer is dependent on the residual signal, which serves as a fault indicator in the overall system and represents the difference between the measured and estimated speed signals from the plant. Due to the increasing demand for these motors, particularly in electro-mechanical applications such as robotics, elevators, and electric-driven railways, a DC motor was chosen as a benchmark to test the proposed method. The output speed of the motor was subjected to four sensor faults: sensor fault, abrupt fault, intermittent fault, and incipient fault. The effectiveness of the suggested approach is demonstrated using MATLAB simulations, and the results show that faults are detected as anticipated with a high-performing response. Therefore, the proposed method was also implemented experimentally in real time and the obtained results showed a close match with those from simulation, thus proving the accuracy and reliability of the proposed methodology for fault detection in the DC motor speed sensor.

Conceptual Foundations of the Synthesis of Safe Train Traffic Control Systems

The article analyses the problem of synthesis of the systems of safe control of critical technological processes on the example of railway automation and remote control systems.It is shown that modern control systems for complex distributed systems, such as a railway transport system, are not implemented with absolute safety. The safety of such systems is limited by considering only their own failures, external failures of control systems and their components, as well as failures of infrastructure objects that directly interact with control devices. Other infrastructure facilities are not considered in any way during automatic control and data transfer to on-board automation.The objective of the article is to present theoretical concept of the synthesis of safe train traffic control systems, considering the capacity of equipping infrastructure facilities with highly reliable and safe means of technical diagnostics and monitoring.A shown simplified structure of the central train traffic control centre considers the results of diagnosing and monitoring all the components of the transportation process.The conditions for the synthesis of completely safe train traffic control systems are formulated along with the accompanying tasks. A comprehensive accounting of the parameters of railway infrastructure facilities and rolling stock will allow reaching a qualitatively higher level of train traffic safety.

Modern slavery and the accounting profession

This first paper in the Special Issue on “Modern slavery and the accounting profession” considers how various branches and functions of the accounting profession in business operations and supply chains are implicated by the move to end modern slavery. Accounting has always been involved with slavery practices. When slavery was legal, accounting focused on reporting slaves as assets and expenses in the accounts. In these more humane times, now that ownership of slaves is illegal, the accounting profession has different functional responsibilities towards modern slavery. These include external reporting in line with and above and beyond requirements of legislation; internal management accounting to build awareness and support planning, control and decision making to reduce modern slavery risk and look for opportunities from mitigation; and audit and assurance to ensure credibility of claims made by business. The papers presented in this Special Issue touch upon some of the key aspects of the connection between modern slavery and management control systems, corporate disclosures and the historical role of professional auditors/the accounting profession, but much remains to be achieved in the research agenda ahead.

Improving the temperature resistance of traction electric motors using a microprocessor control system for modern locomotives

Temperature control of traction electric motors running on direct current with the help of a modern microprocessor-based locomotive control system is analyzed in the paper. Development of a methodology for calculating the temperature of the windings of traction electric motors operating on direct current, based on a modern control system has been discussed. To determine the dependence of the temperature of traction motors on the motion profile and weight of the rolling stock.

Study of technical reasons for fire-burning vehicles

The article presents the authors’ methodology for studying technical ignition causes of cars, with the establishment of the initial fire based on the signs and nature of temperature damage. What is more, subsequent development of the main scenario of fire occurrence is introduced. Modern control system is becoming larger and more complicated day by day and probability of system outage increases with it, so people urgently need to personalize the system of failure diagnostics to conduct real-time monitoring and malfunction diagnosis in production system and take necessary steps to improve its overall reliability and maintainability. According to the presented method of fire research, determination of the ignition causes is carried out by the method of successive elimination. Based on the functional features of the researchable object (a motor vehicle), established by expertise as an initial fire, the ignition of flammable liquid because of leakage from the fuel system, thermal development of the processes accompanying the emergency operation mode of the power grid could be possible ignition causes of the car. The authors pay special attention to the fire hazard of the electric system of a vehicle, which is determined by the fact that its individual elements can serve as a source of burning in case of an emergency in some functional chain. Establishment of initial fire causes increased complexity in connection with relatively small size of cars (especially light cars), fleetness of fires in vehicles and in case of failure to take recovery measures for burning in the initial stage and its development for the entire volume of the car. The results of applying the methodology were positively evaluated by independent expert companies.

Improvement of methods to ensure energy efficiency of ball mills functioning

Mining, metallurgical, enrichment and processing enterprises require a large amount of electricity consumption. Among them, hydrometallurgical and enrichment enterprises currently consume 50-60% of total costs and 5.2% of all world electricity. The main reason for this is the use of traditional ball mills. Including metallurgical, enrichment and processing enterprises consume 5-20% of the electricity produced in the world. The main way to improve the performance of ball mills is to optimize the operating modes of the electric drive and mill equipment, to ensure stable operation of the ball mill and electric motor at full load. To determine such operating modes and ensure the operation of equipment in them, modern control systems, methods for assessing the energy efficiency of ball mills and optimizing the operating modes of electrical systems are required.

Cryptanalysis of Random Affine Transformations for Encrypted Control

Cloud-based and distributed computations are of growing interest in modern control systems. However, these technologies require performing computations on not necessarily trustworthy platforms and, thus, put the confidentiality of sensitive control-related data at risk. Encrypted control has dealt with this issue by utilizing modern cryptosystems with homomorphic properties, which allow a secure evaluation at the cost of an increased computation or communication effort (among others). Recently, a cipher based on a random Affine transformation gained attention in the encrypted control community. Its appeal stems from the possibility to construct security providing homomorphisms that do not suffer from the restrictions of “conventional” approaches.This paper provides a cryptanalysis of random Affine transformations in the context of encrypted control. To this end, a deterministic and probabilistic variant of the cipher over real numbers are analyzed in a generalized setup, where we use cryptographic definitions for security and attacker models. It is shown that the deterministic cipher breaks under a known-plaintext attack, and unavoidably leaks information of the closed-loop, which opens another angle of attack. For the probabilistic variant, statistical indistinguishability of ciphertexts can be achieved, which makes successful attacks unlikely. We complete our analysis by investigating a floating point realization of the probabilistic random Affine transformation cipher, which unfortunately suggests the impracticality of the scheme if a security guarantee is needed.

Expanding functionality of the autonomous voice control system

The article describes the main advantages of voice control systems, notes the shortcomings of the first implemented voice control systems, their functional limitations, and limited use in comparison with modern voice assistants, and also formulates the shortcomings of modern voice control systems. It is noted that with the expansion of functionality, the scope of voice control systems is expanding significantly. The recommendations of leading companies that implement voice technologies, indicating the need to continue research and development in this area. Due to complex calculations in speech recognition, there is a need to use high-speed computers, which makes it difficult to create compact and autonomous voice control systems that work without an Internet connection. At the same time, the growing need for autonomous voice control systems requires a reduction in computational costs, an increase in the speed of calculations by simplifying the methods and algorithms of these systems, implemented in software and hardware in the form of autonomous electronic devices. Methods are distinguished that allow performing recognition with sufficient reliability, such as hidden Markov models and the method for determining mel-frequency cepstral coefficients. In addition, methods are proposed to reduce computational complexity by reducing the number of similar-sounding words included in the command and the commands themselves, and to increase the speed of calculations, the use of electronic components is proposed in the implementation of computational algorithms and their parts. The operability and the possibility of practical application of ways to expand functionality and reduce computational complexity for autonomous voice control systems have been tested and confirmed experimentally, and some of them correspond to the recommendations of leading companies implementing voice technologies.

Redesigning industrial composite production planning and control for energy awareness

The European Union's requirement for eliminating greenhouse gas emissions from all value chains by 2050 affects most of the manufacturing activities all over the continent. The industrial production of composite parts, favored for new designs throughout the aerospace industry, does not constitute an exemption. For securing global competitiveness, CFRP manufacturers need to adapt to increasing fluctuations in energy supply and prices, induced by a growing share of renewable energy sources. Besides employing more efficient production technologies, decoupling of labor and energy intensive tasks will play a key part. Thereby, energy intensive tasks can be performed while general energy supply is high and demand is low, leading to comparatively lower prices. The perspective of energy supply and price becomes a crucial part in the design of modern production planning and control systems, not only for smokestack businesses, but for small and medium load energy consumers as well. In this contribution, a mathematical representation for modeling industrial scale composite manufacturing is proposed. Beside manufacturing's fundamental production planning and control constraints, CRFP manufacturing's very own peculiarities are outlined and considered as well. It is shown how the virtual mathematical representation of a CFRP manufacturing environment can assist in its energy aware redesign and optimization.

Intelligent monitoring of the condition of hydrocarbon pipeline transport facilities using neural network technologies

The national strategic goal of the Russian Federation is to ensure the safety of critical technologies and sectors, which are important for the development of the country's oil and gas industry. The article deals with development of national technology for intelligent monitoring of the condition of industrial facilities for transport and storage of oil and gas. The concept of modern monitoring and safety control system is developed focusing on a comprehensive engineering control using integrated automated control systems to ensure the intelligent methodological support for import-substituting technologies. A set of approved algorithms for monitoring and control of the processes and condition of engineering systems is proposed using modular control robotic complexes. Original intelligent models were developed for safety monitoring and classification of technogenic events and conditions. As an example, algorithms for monitoring the intelligent safety criterion for the facilities and processes of pipeline transport of hydrocarbons are presented. The research considers the requirements of federal laws and the needs of the industry.

USE OF ENERGY-SAVING TECHNOLOGIES IN HIGHER EDUCATION INSTITUTIONS

The article examines the requirements for the creation of an autonomous university, considers alternative measures to solve energy saving problems, shows the effectiveness and necessity of conducting an energy audit of the institution, indicates the actions performed by Khmelnytskyi National University in the framework of energy saving. The methodology for evaluating the effectiveness of measures is similar to the calculation of current energy consumption and energy consumption for the previous representative period. The difference is that when evaluating energy-saving measures, it is necessary to predict how the situation will change after their implementation. This entails a change in many coefficients, such as the rate of energy consumption, the power utilization coefficient, the duration of equipment operation during the year. To save energy, Khmelnytskyi National University built its own boiler house with a capacity of 3,900 kW, which made it possible to disconnect several buildings from the city-wide heat supply network. Solar power plants were put into operation, solar panels were placed on the roofs of the buildings of the educational institution, educational and production bases, sports complex The implementation of the latest technologies for the production and consumption of energy resources, as well as technologies involving the use of alternative energy sources, is possible on the basis of a previously conducted comprehensive energy audit. The feasibility of building an autonomous heating system, which made it possible to disconnect the main buildings from the city-wide heat supply network, has been proven. Taking measures to insulate walls, replace the water supply system, and use heating points increases the energy efficiency of resource use. In addition, the introduction of alternative energy systems, the creation of own solar power plants and modern control systems for them allows you to optimize lighting costs per hectare, reduce costs for electricity needs, and even make money from sales using the “green tariff”. In this way, any higher educational institution can organize and conduct its own measures to increase the energy-efficient consumption of energy resources, conduct information campaigns, involving students and teachers. This will not only improve the energy situation at the university, but will also help save energy at home.

Methodology for assessing the operational efficiency of transport diesel generators

Problem. Today, there is a problem associated with the need to increase the efficiency of railway transport. Recently developed methods for determining the parameters of energy-saving operational work in stable and transient modes, as well as sets of corresponding technical means from various manufacturers allow us to speak of an integrated energy-saving technology. This development relies on the use of electronic controls. It is very effective both when used on new locomotive diesel generators and when retrofitted during a major overhaul. The integrated indicators existing in railway transport were developed without taking into account the capabilities of modern control systems in the formation of both stable and transient modes. Therefore, it is difficult to obtain estimates on their basis that make it possible to compare the efficiency of energy saving of control systems of various manufacturers and the actual payback period under operating conditions. Goal. The purpose of this work is to develop a methodology for assessing the impact of technical controls on improving the operating efficiency of diesel-generators in a relative form, which allows, even at the stage of preparation for the introduction of energy-saving measures, such as modern frequency and power control systems for a diesel-generator, to determine the efficiency of diesel generators in steady state, transient and idling conditions expected during the operation of the vehicle. Methodology. The paper uses methods based on obtaining relative estimates based on well-known ratios for fuel consumption in stable and transient modes. Results. The simple expressions obtained in the work make it possible to evaluate in a relative form the degree of influence of electronic technical systems on improving the operational efficiency of mainline and shunting diesel locomotives without carrying out a time-consuming and material-resources experimental study. Originality. In the case of a mainline locomotive, the expected efficiency from the use of only frequency and power control systems (electronic regulator) is estimated, and in the case of a shunting locomotive, relative estimates allow us to estimate the expected efficiency from the simultaneous use of two control systems: a start-stop system and an electronic regulator. Practical value. The proposed method of relative estimates can be applied to analyze the potential increase in the operational efficiency of diesel generators of shunting diesel locomotives, the fleet of which is a significant consumer of diesel fuel in railway enterprises, mining and metallurgical industries in almost all countries.

Enhanced Ships Operation using Integrated Automation Systems

Global shipping for becoming sustainable will have to organize the ships and each field of shipping industry, in accordance efficient management and operation principles. This will require the adoption of new techniques and the transformation of companies, their ships, systems, and management practices. A modern automation and control system is a fully integrated system covering many aspects of the ship operation. Whether for cargo, passenger or special-purpose ships, Integrated Automation Systems meets every requirement in shipping and offers decisive advantages over the entire "life" of a ship. The adaptation can suit perfectly to the special requirements in shipping and creates the prerequisites for maximum economy, reliability, and safety on board. Integrated Automation includes the propulsion plant operation, power management operation on the auxiliary engines, auxiliary machinery operation, cargo loading and unloading operation, navigation and administration of maintenance and purchasing of spares. The study focuses on implementation of IAS and its contribution in ship's performance and safety. The proposed model incorporates different failure rates for the different sensors of the Integrated Automation system as well as repair actions that need to be performed. The system can experience various levels of deterioration and when a failure occurs, a repair procedure is carried out and the system is restored to its initial fully operational state. A numerical example based on the empirical data is used to illustrate the proposed model.
 
 Received: 23 September 2022 / Accepted: 28 November 2022 / Published: 20 December 2022

Upgrade of the neutral beam heating system on the TCV tokamak – second high energy neutral beam

The TCV tokamak continues to leverage its unique shaping capabilities, flexible heating systems and modern control system to provide a stepladder approach for extrapolations of experimental results from different machines to ITER and DEMO. TCV's configurational flexibility has recently been enhanced by the installation of two heating neutral beams, new dual frequency gyrotrons, removable divertor gas baffles together with upgrades of its diagnostic infrastructure.Plasma regimes with high plasma pressure, a wider range of temperature ratios and significant fast-ion population are now attainable on TCV. A 1.3 MW/28 keV heating beam (NBI-1) has been operated on TCV from 2015 introducing the direct ion auxiliary heating. A second 1MW/50–60 keV high-energy neutral beam (NBI-2) has since been procured, manufactured and installed on TCV in July 2021. NBI-2 injected near anti-co-linearly to NBI-1 is designed to probe plasma physics issues of higher plasma density, fast ion plasma interactions with static and dynamic fields and plasma rotation. The higher NBI-2 energy greatly enhances the operational space for fast ion studies. NBI-2 commissioning is presently ongoing in parallel with TCV experiments using both NBIs.This paper summarises the experience with intensive use and improvements of the NBI-1, together with the status of NBI-2 commissioning.

Improvement of tools for specific prevention of avian salmonellosis

Avian salmonellosis is an infectious disease that occurs in an acute or chronic form and can be caused by one or more species of the genus Salmonella. The source of infection is sick and diseased birds, which can be carriers of Salmonella for a long time, i.e. reservoirs for the pathogen. In addition to chickens, other poultry, especially waterfowl (geese, ducks), as well as pigeons, rodents (mice and rats), insects (cockroaches), domestic animals and humans are also sources of infection. All this leads to a persistent epizootic environmental disease associated with a high risk of Salmonella contamination of industrial poultry. The modern control system of salmonellosis infection should be based on an integrated approach and include not only the implementation of veterinary and sanitary rules and the use of effective therapeutic preparations, but also the use of specific prevention of avian salmonellosis (vaccination). The aim of the study was to conduct the research on the physicochemical and immunobiological properties of inactivated vaccine against avian salmonellosis produced using different oil adjuvants developed by ICTYO GROUP Corporation. Formaldehyde inactivated S. enteritidis culture and a range of adjuvants (ICTYOLANETM11, ICTYOLANETM19, ICTYOLANETM20 and ICTYOLANETM 21) were used to produce the vaccine samples. The vaccine samples were tested for sterility, stability and viscosity by conventional methods. Determination of reactogenicity and antigenic activity of the vaccines was carried out on 38-day-old young laying hens. Upon completion of the tests, the inactivated emulsion vaccine against avian salmonellosis produced using the ICTYOLANETM 11 adjuvant was found to have very high antigenic activity and residual reactogenicity. It is likely that after a series of tests to reduce the residual reactogenic properties of the vaccine by reducing the number of S. enteritidis microbial cells in a single immunizing dose it will be possible to obtain a non-reactogenic and effective preparation for the specific prevention of avian salmonellosis based on the ICTYOLANETM adjuvant.