Field Of Control Systems Research Articles

Time Domain Identification of Structures: Comparative Analysis of Output-Only Methods

The focus of this work is on methods for modal identification of civil structures using output data only. An important family of time domain methods uses autoregressive time series models and exploits formulations developed in the field of system control. Another strategy consists of using methods well tested in the identification of structures on the basis of impulse response or free decay and extending them to the analysis of response signals generated by excitations of a more general nature. A third option refers to the Ho-Kalman minimal realization algorithm, which was extended by Akaike and Aoki to stochastic systems. These approaches, or their combinations, include a sizable proportion of the methods actually used in output-only identification of civil structures subjected to natural excitation, and most of them are based on stationarity assumptions. The question that prompted this study was as follows: what degrees of reliability and accuracy can such methods ensure when they are used, as is often the case in actual practice, in nonstationary conditions? An answer to this question was sought numerically by focusing on nonstationary conditions deemed typical of the actions naturally applied to civil structures.

The Security Measures of FCS in Power Plant

As a new technology of control system, Field Control System (FCS) is being promoted in power plant in China. According to the application status and requirements of FCS in power plant, the author proposes some security measures and suggestions for FCS.

The Analysis and Research of OPC XML-DA Server

The technical defect of the OPC (OLE for Process Control) DA (Data Access) server which is based upon the technology of COM (Component Object Model) has appeared prominently while transmitting the message in the internet. So it's important to bring forward the technical advantage and necessity of OPC XML-DA server based on the web service technology. The transmission of the plant message across the internet have been facilitated, in the meanwhile, the data fusion between MIS (Management Information System) and FCS (Field Control System) have been promoted. This paper presents the scheme of the middleware server which is realized by mean of “gSoap” development kit. The interface of the DA server based on the COM could be connected with web service interface based on the XML (Extensive Makeup Language) / SOAP (Simple Object Access Protocol). The experiment justifies high efficiency and feasibility of OPC XML-DA server in the internet communications.

A Control System for Traffic Light Based on GPRS

On the basis of brief analysis of the deficiencies of the existing traffic light control system. According to the actual needs of the traffic light, a traffic light control system with remote monitoring by using GPRS wireless module is designed. ForceControl configuration software is used as the monitoring software in the control center. To achieve traffic light control and running test, it exchanges information with each intersection of the field control system through GPRS wireless and communication network. The system realizes wireless remote monitoring of traffic lights, retrenches monitoring cost, improves the system stability and reliability, and facilitates the transformation of the system and the increase of traffic intersections.

Design and Realization of Control Circuits of the Micro Milling Machine and the Safety Inspection Function of its Spindle

Based on the analyses of the current research status of PC + NC type control system in micro-machining technical field both at home and abroad, an “IPC + PMAC motion controller” type open CNC system is established. Control circuits of the micro milling machine control system are designed, which include the realization of the functions of spindle status display, feeding tables status display, IPC status display, machine tool alarm, interlocking control of the function buttons and the corresponding indicator light control of spindle cooling, spindle lubrication, spindle alarm and spindle running status. Finally, the safety inspection function of the spindle is achieved through writing corresponding PLC programs. The research of this paper can provide reference for the study of the micro milling machine control system.

지리정보시스템과 관제시스템의 융합에 관한 연구

국가기반 인프라가 IT기반의 네트워크와 맞물려 이에 따른 해킹, 인터넷 침해, 테러 등의 대상이 되고 있으며, IT융합기술 시장의 확장에 따라 위험 대상의 범위 또한 광범위해져 가고 있다 최근 보안관제의 개념이 IT분야와 결합되어 사이버 보안관제에 관한 연구가 진행되고 있으며, 이와 함께 기존 관제 시스템이 타 분야와 융합되어 그 활용 및 중요성이 증가하고 있다. 본 연구는 국가기반인프라가 되는 관제 시스템의 취약점을 분석하고, 융합기술과 접목하여 도출된 문제점을 개선 및 기능을 향상하기 위한 관제 시스템 융합에 관한 연구이다. 연구 대상은 광범위하게 활용되고 있는 'CCTV 관제 분야', ITS를 도입해 운용하고 있는 '교통관제 분야', 다양한 기술들의 활용 연구가 이루어지고 있는 '재난관제 분야'로 정하였다. 최종적으로는 이러한 문제점들을 개선하기 위해 GIS 등의 관련 시스템을 적용하고 향상된 융합 기술을 제안하였다. State-based infrastructure on IT-based network are prone to numerous cyber attack including subsequent hacking and internet infringement. These acts of terrorism are increasing because of the expanding IT convergence technology. Recently, the trend on cyber security monitoring and control researches focus on combining the general idea of security monitoring and control along with IT field and other control systems. This convergence trend has been increasing in both the use and importance. This research analyzes the state-based infrastructure monitoring and control system, its vulnerability as well as its improvement by incorporating the cyber convergence systems to existing systems. The subject of this research is for extensive use of CCTV systems which is expanded for 'CCTV Monitoring and Control Field' as well as 'Traffic Monitoring and Control Field' operated by 'Intelligent Traffic Information System' and Disaster Management Area which is studied in various fields. Eventually, the objective of the paper is to solve these issues, to apply related systems and to suggest improvement on the convergence system.

Means of generating a field control system of an asynchronized turbogenerator

The main advantages of asynchronized turbogenerators (ASTGs) in comparison with traditional synchronous turbogenerators are formulated. Means of generating a field control system for ASTGs that allows one to implement these advantages is presented. The basic requirements for the field system of ASTG are given.

Active Sound Field Control System in Auditoriums

Active Sound Field Control System in Auditoriums

Application of Linux parallel computing based on multithreading in HT-7 poloidal field control system

In order to realize real-time and precise controlling plasma during the experiment of HT-7 tokomak,this paper made use of the parallel system of multi-processors,and designed the attribute and CPU affinity of the two threads in one process.It actualized the feedback control of poloidal field control system,which achieved the goal of real-time control in 1ms at HT-7 tokomak,at the same time obtained the position of plasma by parallel computing.

Kinetics and Reaction Products of Ozone and Surface-Bound Squalene

Abstract Because of the high occupant density in aircraft, the surface chemistry of ozone and squalene, an important component of skin oil, was evaluated. A reaction probability of (45±14)×10−5 was determined for the reaction of squalene (2,6,10,15,19,23-hexamethyl-2,6,10,14,18,22-tetracosahexaene) with ozone (50 parts per billion (ppb)) on a glass plate surface using the Field and Laboratory Emission Cell (FLEC) Automation and Control System (FACS). To more clearly define part of squalene’s indoor environment degradation mechanism, gas-phase and surface-bound products of the squalene+O3 reaction were also investigated. Emitted products were captured in solution, derivatized with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA), and analyzed by gas chromatography and ion trap mass spectroscopy. The identified squalene+O3 reaction products were: 6-methyl-5-hepten-2-one (6MHO, ((CH3)2CCH(CH2)2 C(O)CH3)), glyoxal (ethanedial, HC(O)C(O)H), 4-oxopentanal (4OPA, CH3C(O)CH2CH2 CH(O)), and 6,10-dimethylundeca-5,9-dien-2-one (geranyl acetone). The compound 5,9,13-trimethyltetradeca-4,8,12-trienal is proposed as the other major squalene+O3 reaction product. This compound was determined from mass spectrometry coupled with plausible squalene+O3 reaction mechanisms based on previously published volatile organic compound+O3 gas-phase reaction mechanisms.

Remotely Operated Smart-Well Completions

This article, written by Technology Editor Dennis Denney, contains highlights of paper SPE 112226, "Intelligent Wells to Intelligent Fields: Remotely Operated Smart-Well Completions in Haradh-III," by Ibrahim H. Al-Arnaout, SPE, Saad M. Al-Driweesh, SPE, and Rashad M. Al-Zahrani, SPE, Saudi Aramco, and Zuhed Abdul Rahman, SPE, and Suresh Jacob, SPE, WellDynamics, prepared for the 2008 SPE Intelligent Energy Conference and Exhibition, Amsterdam, 25–27 February. The paper has not been peer reviewed. Multilateral wells with smart-well completions and permanent monitoring systems were integrated with an advanced supervisory control and data-acquisition (SCADA) system that enables real-time remote monitoring and control of downhole and surface equipment from the control room. The design and installation of the automated system was a multidisciplinary project integrating subject experts and tools from well completions, production engineering, facilities, instrumentation, and communications. The system enables an operator in the control room to operate the downhole valves in all the multilateral smart wells remotely through the SCADA system. Introduction The Haradh-III field is in the southernmost part of the Ghawar complex, approximately 100 km west-southwest of Dharan, Saudi Arabia, and has been developed with 32 maximum-reservoir-contact (MRC) multilateral wells, with intelligent completions installed in 28 wells. This arrangement reduces the required well count and achieves higher productivity from each well. Studies showed that developing the Haradh-III field with MRC wells and smart-completion technology would delay water encroachment, improve flood-front conformance and recovery, and reduce water production and operating costs. The concept of intelligent fields was incorporated into the field design to enable continuous monitoring of key reservoir-performance parameters and real-time data transmission from downhole to the engineers' desktops. The surface infrastructure was designed with the communication and power facilities required to connect all the wells to the field SCADA system. The field communication infrastructure was designed as an open architecture to integrate the intelligent-well controls as an independent subsystem of the field-control system. System Overview The Haradh-III-field communications network is a scattered/distributed layout linking all wellsites to the gas/oil separation plant (GOSP). The field-control-sys-tem architecture uses a remote-terminal unit (RTU) at the wellsite connected to a central SCADA application in the GOSP by means of a fiber-optic communications network. In addition to intelligent-completion technology, each well in the field is provided with downhole point-pressure and -temperature sensors and a surface multiphase-flow meter. The field SCADA application acts as a single interface point for all field control. Data hand-off to the field historian occurs at the GOSP. The application also is the integration point for intelligent-completion systems. Fig. 1 shows the field communications network linking the wellsites to the control-room terminal.

Application of tensor decomposition in studying linear induction motors

We consider questions of the development of mathematical and computer software for the analysis of electromagnetic processes in high-speed linear induction motors. It is shown that, upon applying tensor calculation methods to each part, it is possible to solve joint equations for the electric circuit, electromagnetic field, and motor control system.

Study of the DEF Feedback Control System in AC Operation of Superconducting Tokamak

AC operation with multiple full cycles has been successfullyperformed on the superconducting tokamak HT-7. In the experiment, itwas discovered that the saturation of the transformer magnetic fluxwith DEF, a signal name, was one of key aspects that affected the ACoperation. The conditions of DEF were examined through the DEFfeedback control system. By controlling the working patterns of thesubsystems, namely the poloidal field control system and densitycontrol system, it was guaranteed that DEF wouldremain in the non-saturated status.

Field and laboratory emission cell automation and control system for investigating surface chemistry reactions

A novel system [field and laboratory emission cell (FLEC) automation and control system] has been developed to deliver ozone to a surface utilizing the FLEC to simulate indoor surface chemistry. Ozone, humidity, and air flow rate to the surface were continuously monitored using an ultraviolet ozone monitor, humidity, and flow sensors. Data from these sensors were used as feedback for system control to maintain predetermined experimental parameters. The system was used to investigate the chemistry of ozone with alpha-terpineol on a vinyl surface over 72 h. Keeping all other experimental parameters the same, volatile organic compound emissions from the vinyl tile with alpha-terpineol were collected from both zero and 100 ppb (parts per 10(9)) ozone exposures. System stability profiles collected from sensor data indicated experimental parameters were maintained to within a few percent of initial settings. Ozone data from eight experiments at 100 ppb (over 339 h) provided a pooled standard deviation of 1.65 ppb and a 95% tolerance of 3.3 ppb. Humidity data from 17 experiments at 50% relative humidity (over 664 h) provided a pooled standard deviation of 1.38% and a 95% tolerance of 2.77%. Data of the flow rate of air flowing through the FLEC from 14 experiments at 300 ml/min (over 548 h) provided a pooled standard deviation of 3.02 ml/min and a 95% tolerance range of 6.03 ml/min. Initial experimental results yielded long term emissions of ozone/alpha-terpineol reaction products, suggesting that surface chemistry could play an important role in indoor environments.

Case study for voice amplification in a highly absorptive conference room using a negative absorption tuning by the Yamaha Active Field Control system

The Yamaha Active Field Control (AFC) enhances and varies acoustical conditions from the room acoustics using the acoustical feedback in a system, which is properly tuned to the installed room acoustics. The system is primarily used to improve auditory impressions of reverberance, loudness by enhancement of reverberation in time, and energy in a music venue. Here, a negative absorption tuning is demonstrated as beneficial to the presentation room for a simple spoken speech used with a relatively excessive absorption at a middle-sized multiuse conference room. The space occupies 1100 ft2 with a ceiling height of 9 ft. It is designed for demonstration of sound equipment as well as lecture without audio equipment. Since the acoustics in the room are highly absorptive (average absorption coefficient, 0.3), considering a primary use for product demonstration, it causes a flutter echo between longitudinal walls due to less sound energy in a late field. We demonstrate here a system adjustment of the AFC system emphasizing voice amplification as well as an acoustical solution to a defect of a fluttering echo here. Acoustical descriptors such as RT, echo diagram, and SPL are discussed for a tuned room acoustics with the AFC system.

Development of a magnetic field control system

Development of a magnetic field control system

Attractive Fixture System Based on Magnetic Field and Friction Force for Numerically Controlled Machining of Paper Honeycomb Core

In order to improve the precision of machining and reduce the processing cost of paper honeycomb core, a new method is presented to fix the honeycomb core work piece to the working platform using magnetic and frictional forces. In this method, iron powder is used as a medium instead of the traditional adhesive-based material to achieve the bonding between the work piece and the working platform. Iron powder is poured into honeycomb cells until it reaches the desired height using a numerically controlled iron powder feeder system. In addition, a magnetic working platform is manufactured and placed on top of the station of the milling machine. The magnetic field produced by the magnetic working platform is leaded to the iron powder while the magnetic field control system switches on. More precisely, the mutual magnetic attraction between the iron powders located in different cells of the honeycomb and between the iron powder and the platform is generated. While cutting force is applied to the work piece, two types of friction force occur. One is between the iron powder and the wall of the honeycomb cells, and other one is between the work piece and the working platform. Once the resultant friction force balances the machining load, the work piece will be then fixed to the platform. In this paper, a new bonding system based on the new method is introduced and demonstrated.

The virtual microphone technique in active sound field control systems

Active Sound Field Control (AFC) has been proven very useful in reverberation enhancement applications in large rooms. However, feedback control is required in order to eliminate peaks in the frequency response of the system. The present research closely follows the studies of Shimizu in AFC, in which smoothing of the rooms transfer function is achieved by averaging the impulse responses of multiple microphones. ‘‘The virtual or rotating microphone technique’’ reduces the number of microphones in the aforementioned AFC technology, while still achieving the same acoustical effects in the room. After the impulse responses at previously specified pairs of microphone positions are measured, the ratio of transfer functions for every pair is calculated, thus yielding a constant K. Next, microphones are removed and their impulse responses are reproduced by processing the incoming signal of each pair through a convolver, where the computed K constants have been previously stored. Band limiting, windowing and time variance effects are critical factors, in order to reduce incoherence effects and yield reliable approximations of inverse filters and consequently calculations of K. The project is implemented in a church lacking low frequency reverberation for music and makes use of 2 physical and 2 virtual microphones.

Design analysis on the magnetic field control system in compact ITER

Design analysis on the magnetic field control system in compact ITER

Recent progress of HT-7 superconducting Tokamak PFPS control system

The recent progress of the poloidal field control system of the HT-7 super-conducting Tokamak is presented. The distributed control system (DCS) was implemented on the poloidal field power supplies (PFPS) in 1998. The successful development of the new PFPS trigger system allowed the control cycle of the PF power supplies to reach 1–1.2 ms. The response speed of the control system was improved by ten times with reference to the former system. Secondly, based on software de-coupling of plasma equilibrium parameters, a multivariable feedback control scheme was implemented. Thirdly, the efficiency of HT-7 experiment operation was greatly improved by realizing the discharge experiment database of HT-7.