• 한국기계가공학회지
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• 제10권5호
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• pp.13-19
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• 2011

In this paper, the active monitoring and control system is developed. This system can monitor the status of high the speed spindle in real time during its processing, and can analyze its influence of dimensional accuracy and processing if any, and can control the machining condition to realize the machining system equipped with active monitoring and self-diagnostic features. Machining experiment was performed on 3 materials Al, Brass and S45C in order to derive the relation between active monitoring and control algorithm by the machining load. In addition, we measured surface roughness of processing specimen along with the data change of spindle rotating speed and conveying speed according to variation of machining load. Based on these experiments, we derived relations for each material that can be applied to the control algorithm to allow self control of the rotating speed and conveying speed according to the machining load.

• Journal of Advanced Marine Engineering and Technology
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• 제28권5호
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• pp.811-817
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• 2004

Recently embedded systems are widely used in various industrial fields as supervisory controller because they have many merits. One of merits seems to be that operating environment of embedded system is the same as development environment using PC. That makes developing and manufacturing period shorten and also proper time to market Most of all machinery have sequential control system for their maneuvering which is composed of relays. contacts. timers. etc. In this paper. software sequential control system is proposed to be able to replace hardware sequential control system by using embedded system A lot of merits by the software sequential control system can be expected in the respect of economic reproduction, intelligent technologies and utilities, And porting of LINUX operating system to embedded system is carried out and device drivers and interface boards for LINUX 05 are designed for controlling air compressor by software Internet remote control and monitoring system of air compressor is implemented with Java script and CGI for these purposes. The experiment for operating air compressor system is taken through internet networks. The results show that developed system can be used for real plant.

• Journal of Advanced Marine Engineering and Technology
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• 제28권8호
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• pp.1291-1298
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• 2004

In development of monitoring and control systems, one of the most important points is to consider a redundancy so that the system can be operated normally although hardware faults are partly occurred. The purpose of this paper is to introduce a monitoring and control system with a redundancy function for I/O servers and communication networks. I/O servers composed with an active server and a standby server. Each server also has 3 communication ports, 2 ports of them were connected to field units and the other 1 port was connected to the other server. Field units have to be constructed to 2 communication ports connected I/O servers through communication lines. Also, server communication module was implemented for analyzing and handling fault elements. and was submodularized for linking easily with a monitoring and control module. An experiment with 2 servers and 2 field units was constructed to demonstrate its effectiveness.

• 한국구조물진단유지관리공학회 논문집
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• 제5권3호
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• pp.191-201
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• 2001

In spite of the increasing construction of segmental PSC box girder bridges, the techniques associated with real-time monitoring, construction control and safety assessment during construction have been less developed compared with the construction techniques. Thus, the development of an integrated system including real-time measurement and monitoring, control and safety assessment system during construction is necessary fur more safe and precise construction of the bridges. This study presents a prototype integrated monitoring system for preventing abnormal behavior and accidents under construction stages, that consist of behavior control system for precise construction, reliability-based safety assessment system, and structural analysis. Also, a prototype software system is developed on the basis of the proposed model. It is successfully applied to the Sea-Hae Grand Bridge built by FCM. The integrated system model and software system can be utilized for the safe and precise construction of segmental PSC bridges during construction.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.116-119
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• 2004

The existing monitoring and control systems of utility-pipe conduit (power tunnel, cable tunnel etc) have established communication lines using optical fiber, leaky coaxial cable (LCX), and several kinds of control cable. Due to the properties of the used media, the cost of equipment is considerably high and the maintenance of the system is difficult. Also, the term of carrying out is long so that the extension of the system is in difficulty. Now it is desirable to adopt Power Line Communication (hereinafter, PLC) technology in the monitoring and control systems and use the existing low-voltage power-line for lamplight as communication line. This will lead the reduction of the construction cost and the easy maintenance of the system. In this paper, we research the characteristics of PLC in conduit, design and manufacture the field test system, and analyze the performance of the system by field test. Then, we introduce the reliable monitoring and control system of utility-pipe conduit using PLC.

• 대한전기학회논문지:시스템및제어부문D
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• 제52권5호
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• pp.268-276
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• 2003

In this paper, we present a new control and monitoring technique for a power system using CAN(Controller Area Network). Feedback control systems having co'ntrol loops closed through a network(i.e. Ethernet, ControlNet, CAN) are called NCSs(Networked Control Systems). The major problem of NCSs is the variation of stability property according to time delay including network-induced delay and computation delay in nodes. We present a new stability analysis method of NCSs with time delay exploiting a state-space model of LTI(Linear Time Invariant) interconnected systems. The proposed method can determine a proper sampling period of NCSs that preserves stability performance even in NCSs with a dynamic controller. We design CAN nodes which can transmit control and monitoring data through CAN bus and apply these to NCSs for a power system. The results of the experiment validate effectiveness of our control and monitoring technique for a power system.

• Journal of Biosystems Engineering
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• 제24권1호
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• pp.25-30
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• 1999

The effectiveness of many greenhouse environment control methodologies depends on the growth information of crops. Acquisition of the growth information of crops requires a non-invasive and continuous monitoring method. Crop growth monitoring system using digital imaging technique was developed to conduct non-destructive and intact plant growth analyses. The monitoring system automatically measures crop growth information sends an appropriate control signal to the nutrient solution supplying system. To develop the monitoring system, a linear model that explains the relationship between the fresh weight and the top projected leaf area of a lettuce plant was developed from an experiment. The monitoring system was evaluated buy successive lettuce growing experiments. Results of the experiments showed that the developed system could estimate the fresh weight of lettuce from a lettuce image by using the linear model and generate an EC control signal according to the lettuce growth stage.

• 연구논문집
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• 통권24호
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• pp.129-140
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• 1994

Design and implementation of monitoring and control system using dual-microprocessor node is presented for real time process. The proposed system is implemented with 2 of the single chip microprocessors in tightly coupled mode and results in speed up of $s_p=1.74.$ Under the assumption that the nodes are interconnected in multidrop. the overall system performance such as average throughout-delay characteristics and effective throughput are analyzed using M/G/1 gueueing model, and results show that the proposed node can be used to medium sized distributed monitoring and control system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.331-333
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• 2005

In this paper, we implemented the monitoring and control of geothermal heating and cooling system using mobile devices. The main idea of this system is to provide the convenience if the system can be controled in remote place with monitoring using the mobile devices like PDA. Basically, the system consists of the Server-Client structure divided into two parts, one is PDA and PC, the other is PC and PLC(Programmable Logic Controller). The PDA, which is equipped with Windows CE as as, monitors the status of the devices (motors and sensors, etc) attached to PLC and controls them. This does the system to be controled by the commands, which we assume to control, with wireless transmission between PC and PLC. The PDA parts are responsible for monitoring and control the devices connected to the PLC, and the PC part which equipped with the application is to provide the relation between PDA and PLC. The Ladder Program is used to control the sequences of the PLC..

• 한국컴퓨터산업학회논문지
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• 제6권3호
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• pp.509-518
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• 2005

원격 모니터링 시스템(RMS; Remote Monitoring System)은 산업의 자동화 과정에 따라 다양한 분야에 적용되고 있으며, 단순한 상태 감시기능에서 멀티미디어 인터페이스 기반의 실시간 제어 기능을 갖는 복합 응용시스템으로 발전하고 있는 추세이다. 본 연구에서는 네트워크로 연동된 원격 사이트의 타겟 시스템(target system)을 클라이언트의 웹 브라우저에서 모니터링 할 수 있는 감시기능과 특정 동작을 제어할 수 있는 제어기능을 갖는 웹 기반 모니터링 시스템을 개발하였다. 개발 시스템은 클라이언트가 웹 브라우저에서 타겟 시스템의 상태를 실시간으로 감시할 수 있는 모니터링 기능, 클라이언트가 모니터링 화면에서 특정 모듈의 값을 설정함으로써 시스템의 상태를 제어하는 출력제어 기능, 클라이언트가 웹 환경에서 타겟 시스템의 환경 변수를 직접 설정 또는 변경할 수 있는 환경설정 기능, 네트워크에 연동된 화상카메라를 이용하여 타겟 시스템 주변 환경을 비디오로 감시할 수 있는 비디오 감시기능 등으로 구성되어 있다. 본 RMS는 웹 기반의 인터페이스로 타겟 시스템에 쉽게 접근 및 관리가 가능하며, 특히, 무인 자동화 설비 및 폐쇄 공간 등에서 유용하게 활용될 수 있다.