Components Of Control System Research Articles

Electric Actuator Controller Design for Guided Missile Based on FPGA

The electric actuator system is one of the key components in flight control system. Its performance impacts on the flight dynamic performance greatly. In order to deal with the disadvantages of the traditional electric actuator and upgrade the electric actuator system for guided missile, the electric actuator controller based on FPGA is designed. The hardware design is divided into different parts and presented in details one by one. Also the software structure is shown and its functions are introduced. The controller designed features fast response, high precision, great stability and miniaturization. Several ground tests verify its feasibility and stability, proving that it is a preferable choice for the electric actuator system in the guided missile.

A propagation model with defensive measures for PLC-PC worms in industrial networks

• A novel mathematical model for worms spreading in a two-layered PLC-PC coupled network is proposed. • The disease-free and endemic equilibriums of the model are acquired. • The numerical and simulation experiments of the model are performed. • The effectiveness of different defensive measures on the security of PLC-PC coupled networks is discussed. • The effectiveness of extending the connection surface on the security of PLC-PC coupled networks is discussed. Programmable logic controllers (PLCs) are important components of industrial control systems (ICSs), which are digital electronic devices with microprocessors and lack network security considerations. With the explosion of cyber-attacks on the ICS network, the concept of the worm known as PLC-PC worm that can spread between the Internet and ICS network has attracted a great deal of attention. In this paper, for the first time, we propose a propagation model to explore the spread behavior of PLC-PC worms across the PLC-PC coupled network. Theoretical analysis of the model shows the disease-free and endemic equilibriums of the network with defensive measures. And the stability of the model is examined by an epidemic threshold value. Several numerical and simulation experiments are presented to illustrate the analysis. Based on the results, some ideas for restraining the spread of PLC-PC worms or reducing the security threats of the ICS network are suggested.

Robust <inline-formula> <tex-math notation="LaTeX">$H_{\infty}$ </tex-math> </inline-formula> Control of Lurie Nonlinear Stochastic Network Control Systems With Multiple Additive Time-Varying Delay Components

In order to further solve the stability problem in the actual network control systems, this paper first simultaneously considers the controlled object system delay and network time delay in the Lurie nonlinear stochastic network control systems. Among them, the controlled object system delay is multi-time delay and the network time delay is two additive time-varying delay component. The proposing of the two additive time-varying delay components in network control systems has advantages in producing less conservatism over the previous one with a combined delay. By employing the method of improved free weighting matrix and constructing a Lyapunov–Krasovskii functional, less conservative robust $H_{\infty }$ stability criterion is established and the controller is designed for the system in this paper. Some numerical examples are given to demonstrate the applicability of the proposed method.

Вдосконалення бухгалтерського обліку як основної складової системи внутрішнього контролю на підприємстві

Вдосконалення бухгалтерського обліку як основної складової системи внутрішнього контролю на підприємстві

Оцінка ризиків як компонент системи внутрішнього контролю підприємства

Оцінка ризиків як компонент системи внутрішнього контролю підприємства

The Effect of Internal Control Systems and Procrastination on Public Sector Employees

Internal control is a control mechanism that keeps in check the structure for it to operate within the intended parameters and target objectives. The paper offers an overview effectiveness of internal control on whether it achieves the purpose of control the organisation in reducing the laziness in public sector employees. The overall design approach is through the analysis of internal control systems from the Committee of Sponsoring Organisation (COSO) framework. Data was collected through the distribution of questionnaires towards 106 government organisations based on the contents of five components of internal control, which consist of the control environment, risk assessment, control activities, information and monitoring activities. A total sample of 118 government employees returned the questionnaires. Through the analysis of the internal control system, the overview is then observed on whether it would improve overall organisational performance. The study indicated that only a single component of internal control systems (monitoring) is an effective mechanism towards reducing procrastination. The usefulness on whether having strong controls can improve overall organisation performance in the public sector provides a different perspective as government employees have different motivations from private sector employees. The paper contributes towards understanding human behaviour in terms of its reaction towards control systems. It is also from a public sector viewpoint of which internal control effectiveness must be strong in order to increase effectiveness.

A Novel Intrusion Detection Method in Train-Ground Communication System

At present, the train-ground communication system based on the wireless communication protocol is a very important component of communication-based train control (CBTC) systems in intelligent transportation. Its information security is worthy of attention. In order to guarantee the security of the train-ground communication system, this paper proposes an improved AdaBoost multi-classification intrusion detection method based on the n-gram model. First, the n-gram model is used to model the state transitions of the IEEE 802.11 protocol. Then, a typical normal behavior set and typical abnormal behavior sets are obtained by learning and they can portray typical behaviors of their respective classes. Furthermore, a similarity measure algorithm is proposed to construct AdaBoost weak classifiers, which improves the classification effect of AdaBoost algorithm. At last, an AdaBoost multi-classification algorithm is presented to detect and identify the attacks. Experiments prove that the algorithm can effectively detect and distinguish attack types in the train-ground communication system.

Reliability of Cluster-Based Nodes in Wireless Sensor Networks of Cyber Physical Systems

Sensors are a crucial component of any intelligent control system. Wireless sensor networks (WSNs) are one of the most rapidly developing information technologies and promise to have a variety of applications in the Internet of Things and for mission critical and safety relevant applications. Clustering is one of the important methods for prolonging the network lifetime in WSNs. It involves grouping of sensor nodes into clusters and electing cluster heads for all the clusters. Reliability is one of the most important attribute of such systems. The main drawback of the wireless sensor network is the restricted power sources of the sensing elements. Expanding the lifetime of the wireless sensor systems, energy preservation measures are vital for enhancing the execution of WSNs. This paper proposes method for increasing autonomy time of sensors in cluster-based WSNs prolongation using redundancy of batteries. In the paper Markov model for reliability analyses of sensor node in cluster-based WSN with proposed method is described. On the base of developed model the boundary value of reliability parameters for automatics in different failure modes is analyzed.

Concept of information resources management in 4P-environment

The main modern problem of projects and programs portfolios management in enterprises is where to get timely, high-quality, complete information for the successful implementation of projects. Based on this, in the paper is proposed to apply an approach to the management of information resources in 4P-environment. The essence of using this approach for information resources management is that the creation and use of such a resource is considered as a component of the functional add-in, which concentrates the information flows of the project / program / portfolio management tools and enterprises (in terms of project activities) with all the attributes of implementation and control system components. The purpose of the work is a description of the information resources management concept in 4P - environment of enterprise. The classification of information resources was carried out in accordance with the proposed features: by place in the information space of the project-oriented enterprise, by the form of use of information resources, by shift of information resources, by the source of information, by place in information processes. The distribution of information resources classes across three levels of the organization is considered, and a structure is proposed that allows one to formally operate with information resources management processes: from outside the enterprise, from the enterprise, from projects and programs, from project portfolios. Consider the functions of information resources management in the context of the presented classes. It is necessary that these models of management to enter in the functional add-in and increase the level of automation in the 4P environment. It was determined that the system of functions of the add-in in part of information resources management should be quite complex, multidimensional, based on a powerful methodological basis to meet the needs of the 4P-environment for managing information resources. It was concluded that for this, first of all, it is necessary to “algorithmize” each information resources management function and highlight common procedures in them, and will form the basis of the management subsystem of the functional superstructure, is a direction for further research.

Strategic command of the armed forces of Ukraine as a component of the state control system

Strategic command of the armed forces of Ukraine as a component of the state control system

Hierarchical robust switching control method with the Improved Moving Filaments equilibrium reconstruction code in the feedback for tokamak plasma shape

The paper describes a new hierarchical tokamak plasma shape control method implemented in the system with switching robust controllers and matching state vectors. A system robustness was achieved via the H∞ loop-shaping design. A novel modeling approach was used for the feedback system simulation: tokamak plasma equilibrium was calculated by the reconstruction code receiving the sum of experimental scenario signals and the output signals of a linear parameter varying (LPV) model, and sending the output to the multivariable plasma shape controller to close the loop. The LPV plant model is based on plasma equilibria reconstructed from the experimental data of the spherical tokamak Globus-M and is used to simulate plasma responses to small deviations from tokamak discharge scenario. The control system components were designed and combined to achieve high-performance operation during short pulses of plasma with total duration of about 200 ms and the divertor phase time length of 20–25 ms. The non-iterative Improved Moving Filaments method was developed for the plasma equilibrium reconstruction with the simultaneous determination of coordinates and currents of filaments. The plasma shape is controlled via the magnetic field at X-point and poloidal fluxes on a plasma separatrix, without calculation of the gaps between the plasma separatrix and the first wall. The hierarchical feedback control method was used in simulations of the entire plasma discharge with the transition from the limiter to the divertor plasma magnetic configuration. The control system was discretized and simulated on a high-speed computer to be prepared for application in Globus-M experiments by a real time test bed.

Pengendalian Intern Terhadap Sistem Pemungutan Pajak Reklame Pada Badan Pendapatan Pengelolaan Keuangan Dan Aset Daerah (Bppkad) Kabupaten Temanggung

Good internal control is very important to achieve the main goals of a company, therefore the purpose of this Final Project is to know the application of internal control structure of advertisement tax collection system at Badan Pendapatan Pengelolaan Keuangan dan Aset Daerah (BPPKAD) Kabupaten Temanggung and to identify the conformity with the components control according to PP Nomor 60 Tahun 2008 about The Government Internal Control System. The data used are qualitative data, primary data, and secondary data. Data collection using questionnaire method, interview, observation, and literature study. The writing methods of this final project are description and exposition. The result of this Final Project shows that the application of internal control of advertisement tax collection system at BPPKAD Temanggung Regency has been run effectively and has been run in accordance with the design of components of Government Internal Control System (SPIP). In the component of control activities that is the separation of duties, there are still dual positions. To reduce the misuse of authority, BPPKAD Kabupaten Temanggung should add additional employees.

An Improved Torque and Current Pulsation Suppression Method for Railway Traction Drives Under Fluctuating DC-Link Voltage

For railway traction drives, the active front end usually adopts a single-phase rectifier. However, the dc-link voltage of this single-phase rectifier contains a second-order fluctuating component due to the fluctuation of the instantaneous power at both the ac and dc sides. Fed by the fluctuating dc-link voltage, the traction motor suffers from severe torque and current pulsation. The hardware solution with an additional LC resonant filter is simple, but it will reduce the power density of the system. An alternative solution is to eliminate the beat component in the stator voltage/current through modulation ratio or frequency compensation. However, it is difficult to achieve high performance for the conventional feedforward method. In this paper, an improved closed-loop torque and current pulsation suppression method is proposed, which can eliminate the q -axis current pulsation component in the field-oriented control system through frequency compensation. The torque pulsation suppression is also achieved automatically. Simulation and experimental results show that the proposed scheme can effectively reduce the torque and current pulsation in various operation modes compared with the conventional feedforward method.

The British army, information management and the First World War revolution in military affairs

ABSTRACTInformation Management (IM) – the systematic ordering, processing and channelling of information within organisations – forms a critical component of modern military command and control systems. As a subject of scholarly enquiry, however, the history of military IM has been relatively poorly served. Employing new and under-utilised archival sources, this article takes the British Expeditionary Force (BEF) of the First World War as its case study and assesses the extent to which its IM system contributed to the emergence of the modern battlefield in 1918. It argues that the demands of fighting a modern war resulted in a general, but not universal, improvement in the BEF’s IM techniques, which in turn laid the groundwork, albeit in embryonic form, for the IM systems of modern armies.

Active vibration control of a hoop truss structure with piezoelectric bending actuators based on a fuzzy logic algorithm

Active vibration control of large flexible space structure is a challenging topic in the system dynamics and control of spacecraft. This paper proposes a novel approach for vibration control on a large hoop truss structure, typically used as mesh satellite antenna. First, to suppress the first-order bending modal response of the hoop truss structure with an initial disturbance, a piezoelectric bending actuator with excellent bending actuation performance was carefully designed as a key component of an active vibration control system. Then, the actuating characteristics of the actuator and the dynamic equations of the active structure were analyzed and formulated based on a finite element method. In order to improve the vibration-attenuating effect of the control system, a Mamdani-type fuzzy logic algorithm was employed in a closed-loop control system. Finally, simulations and experiments were implemented to validate the effectiveness of the proposed active control approach and structure. The experimental results showed that the decay time of first-order bending modal response (around 0.34 Hz) of control system reduces by 75% compared with that of the uncontrolled system. The results demonstrate that the proposed active vibration control system has good application potential in controlling the bending modes of a large flexible spacecraft.

Effect of Internal Control System on Employee Performance of Small-Scale Manufacturing Enterprises in Ondo State, Nigeria

The study was aimed at examining the influence of internal control system on employee performance. The population was 4,500 enterprises registered with the Nigerian Association of Small Scale Industrialists (NASSI) in Ondo State, out of which 195 randomly selected manufacturing enterprises formed the sample of the study. Primary data were collected and analysed using percentages and mean. The hypothesised model structure was analysed using ordered logistic regression with the significant level at p=0.05. The Pseudo R2 of 0.0353 indicated that the significant independent variables of the model accounted for 3.53% variation in the employee performance. Other factors which did not form part of the variables of the model accounted for the remaining variation. The study revealed that control environment and monitoring have significant effect on employee performance. The study concluded that internal control system significantly have influence on employee performance of small scale manufacturing enterprises in Ondo State, Nigeria. It was recommended that small scale manufacturing enterprises should give priority to be implementation of internal control system components since they influence employee performance and ultimately organisational performance.

Coherent transition radiation from femtosecond electron bunches at the accelerator-based THz light source in Thailand

A THz radiation source based on electron linear accelerator (linac) has been built and commissioned at the Plasma and Beam Physics (PBP) Research Facility, Chiang Mai University (CMU) in Thailand since 2005. The accelerator system consists of a thermionic cathode RF electron gun, a magnetic bunch compressor in a form of an alpha-magnet, an S-band travelling-wave linac structure, beam steering and focusing magnets, beam and radiation diagnostic instruments, control system and other support components. Electron bunches with an average kinetic energy of about 8 MeV, a bunch charge of 100 pC, and a bunch length of 300 fs can be produced from the PBP-CMU electron linac system. Coherent THz radiation generated via transition radiation technique is used as a source of the THz spectroscopy and THz imaging applications. The measured power spectrum indicates that the radiation obtained from short electron bunches covers the frequency range of 0.15–1.80 THz or the wavenumber range of 5–60 cm−1. Experimental results reveal that a peak radiation power as high as 0.2 MW per micropulse and an average radiation power of 2.5 mW can be obtained. Generation and characterization of the coherent THz transition radiation as well as some examples of experiments to achieve electron bunch length and radiation power spectrum are reported and discussed in this paper.

Centralised versus decentralised signal control of large‐scale urban road networks in real time: a simulation study

Recently, signal control strategies with decentralised logic have been developed to tackle the traffic congestion problems of urban road networks. Such strategies aim at network-wide traffic flow efficiency improvement via local actions, thus low design effort and infrastructure investment. This study presents, compares, and evaluates two such innovative approaches: the job scheduling algorithm comprising the local control component of the scalable urban traffic control (SURTRAC) system and the max- or back-pressure algorithm. The approaches are also compared against traffic-responsive urban control (TUC), a well-established strategy with centralised logic. Evaluation is based on the AIMSUN simulation model of the city centre of Chania, Greece. The study results indicate that the TUC and max-pressure retain performance independently of the prevailing traffic conditions, while also being computationally simpler than job scheduling. Both decentralised approaches require frequent (high-resolution) and relatively accurate measurements; on the other hand, TUC, although less demanding in this respect, calls for communication lines between the junction controllers and the central computer. Finally, compared with both decentralised approaches, the TUC provides a signal plan sequence with less excessive differences between each other, thus fewer disturbances to the common network users. Nevertheless, for more comprehensive conclusions, more investigations, including field trials, would be needed.

The industrial internet of things (IIoT): An analysis framework

Historically, Industrial Automation and Control Systems (IACS) were largely isolated from conventional digital networks such as enterprise ICT environments. Where connectivity was required, a zoned architecture was adopted, with firewalls and/or demilitarized zones used to protect the core control system components. The adoption and deployment of ‘Internet of Things’ (IoT) technologies is leading to architectural changes to IACS, including greater connectivity to industrial systems. This paper reviews what is meant by Industrial IoT (IIoT) and relationships to concepts such as cyber-physical systems and Industry 4.0. The paper develops a definition of IIoT and analyses related partial IoT taxonomies. It develops an analysis framework for IIoT that can be used to enumerate and characterise IIoT devices when studying system architectures and analysing security threats and vulnerabilities. The paper concludes by identifying some gaps in the literature.

A New Design for Live Neutron Event Data Visualisation for ISIS and the ESS

Viewing and reducing event data live during an experiment is an important component of contemporary experiment control systems. At ISIS a simple TCP streaming mechanism for neutron event data allows data to be processed by Mantid during an experiment; however, this existing solution is likely to encounter performance issues with the new generation of acquisition hardware. As part of an ESS in-kind collaboration, ISIS is working on developing a new data streaming system based on Apache Kafka for managing and delivering live experiment data to multiple clients. This work provides an ideal opportunity to replace the existing ISIS streaming mechanism with this new system, which not only provides enhanced functionality for ISIS but also functions as a prototype for developing and testing requirements of the ESS.