• 제목/요약/키워드: production process control

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화학 및 가스 공정산업에서 주요 공정제어 기술 (Major Control Techniques for Chemical and Gas Process Industries)

  • 유성진;이창준;이종민
    • 한국가스학회지
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    • 제15권1호
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    • pp.1-8
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    • 2011
  • 최근 석유 위주의 에너지원에서 가스나 신재생에너지와 같은 새로운 에너지원을 생산 혹은 이용하는 공정들에 대한 연구가 활발한 가운데 이러한 공정들의 상업화를 위해서는 조업 중 에너지 절감과 생산 단가의 경제성 확보가 필수적이며, 이를 위해서는 적합한 공정제어 기법의 도입이 필수적이라 할 수 있다. 본 논문에서는 지난 50여 년간 공정산업에 적용된 다양한 공정제어 기법 중 큰 기틀이 되는 몇몇 기술을 소개하고, 가스 관련 공정의 응용 예 및 앞으로 나아갈 방향에 대해 논하였다.

Workload Allocation Methods in Discrete Manufacturing Systems:Model and Optimization

  • Yingwen, Zheng
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.1362-1366
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    • 2003
  • Workload programming is allocating suitable workloads of production process according to the needs of products, which would minimize the total cost of both work and stock under some constraint conditions. In this paper, a production process flow chart of discrete manufacturing is presented by a Petri net, and the optimization model of workload-stock is established. An approach of the optimal workloads is provided by means of the integer matrix theory. An example is given to verify this method.

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품질특성이 선형적으로 변하는 경우의 목표 품질수준과 생산량의 결정 (Control Procedure for a Process Subject to Discrete Linear Shift in Quality Characteristic)

  • 김내헌
    • 산업경영시스템학회지
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    • 제10권15호
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    • pp.39-44
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    • 1987
  • A model for obtaining optimal target value and optimal production quantity of the process is described when the mean quality characteristic decreases according to the increase of production quantity. Two different cases are considered where defective items can be either sold at a reduced unit price or discarded. Some numerical examples are also given.

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PHB 생산의 최적화 및 제어를 위한 이단유가식 배양의 전산모사 (A Simulation Study of Two-stage Fed-batch Culture for Optimization and Control of PHB Production)

  • 이재호;이용우;유영제
    • 한국미생물·생명공학회지
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    • 제20권6호
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    • pp.668-676
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    • 1992
  • Alcaligenes eutrophus에 의한 poly-Beta-hydroxybuty-rate(PHB) 생산을 최적화하기 위해서 1단계에서는 성장을 최대화하고, 2단계에서는 생산을 최대화하는 이단 유가식 배양을 채택하였다. 성장단계에서 탄소원과 질소원의 최적농도는 회분식 배양 모델로부터 결정되었는데, 각기 16.64g/l와 0.54g/l이었다. 생산단계에서 질소원의 경우, 유가식 배양실험을 통해 0.07g/l가 최적인 것으로 나타났다. 탄소원의 최적농도는 모사로부터 결정되었고 이때 최적 전환시간도 함께 결정되었다. 생산공정의 제어를 위하여 시간지연을 고려한 적응비례 되먹임제어를 이용한 결과, 탄소원 농도 및 질소원농도를 최적의 상태로 유지시킬 수 있었다.

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제조 리드타임 단축을 위한 NC 가공공정에서의 실시간 모니터링 시스템 모형 - 선박용 엔진블록 가공공정을 중심으로 - (A Real-Time Monitoring System Model for Reducing Manufacturing Lead-Time in Numerical Control Process - Focusing on the Marine Engine Block Process -)

  • 공명달
    • 대한안전경영과학회지
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    • 제20권3호
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    • pp.11-19
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    • 2018
  • This study suggests a model of production information system that can reduce manufacturing lead time and uniformize quality by using DNC S/W as a part of constructing production information management system in the industrial field of the existing marine engine block manufacturing companies. Under the effect of development of this system, the NC machine interface device can be installed in the control computer to obtain the quality information of the workpiece in real time so that the time to inspect the process quality and verify the product defect information can be reduced by more than 70%. In addition, the reliability of quality information has been improved and the external credibility has been improved. It took 30 minutes for operator to obtain, analyze and manage the quality information when the existing USB memory is used, but the communication between the NC controller computer and the NC controller in real time was completed to analyze the workpiece within 10 seconds.

rpm 변화를 고려한 최적의 공정 평균과 상한 규격의 결정 (Determination of the Optimal Process Mean and Upper Limit with considering the rpm(rate per minute))

  • 송우복;안광일;김성집
    • 품질경영학회지
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    • 제26권1호
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    • pp.61-73
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    • 1998
  • The quality control literature contains a substantial number of articles concerned with how to optimally choose control limits in order to minimize production cost. The purpose of the this study is to determine the economic setting for the process mean of an industrial process. In this study it is assumed that the lower control limit is set by government regulations and the u, pp.r limit and process mean are chosen based on economic considerations. Much research has been conducted on this problem under the condition of the fixed rpm(rate per minute). However a variance can be increased in proportion to the level of rpm and the increase of the variance can change the optimal process mean. Therefore, it is desirable to determine both the process mean and the level of rpm simultaneously. In this paper, a mathematical model is presented which considers the u, pp.r limit and the rpm as variables.

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전기화학적 금속 3D 프린터의 적층 조건 연구를 통한 마이크로 코일 제작 (The Micro Coil Production through Research on the Additive Conditions of Electrochemical Metal 3D Printer)

  • 김영국;강동화;김성빈;유봉영
    • 한국표면공학회지
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    • 제53권4호
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    • pp.138-143
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    • 2020
  • In this study, we produced a coil of micro-pattern that can be used for electromagnetic wave absorber, heating material, wireless charging, sensor, antenna, etc. by using electrochemical additive manufacturing method. Currently, it contains research contents for manufacturing a micro pattern coil having practicality through control of process control variables such as applied voltage, distance between electrode, and nozzle injection. Circulation of the electrolyte through the nozzle injection control can significantly contribute to improving the surface characteristics of the coil because of minimizing voltage fluctuations that may occur during the additive manufacturing process. In addition, by applying the pulse method in the application of voltage, the lamination characteristics of the plated body were improved, which showed that the formation of a fine line width plays an important role in the production of a micro pattern coil. By applying the pulse signal to the voltage application, the additive manufacturing characteristics of the produced product were improved, and it was shown that the formation of a fine line width plays an important role in the production of a micro pattern coil.

생산계획 수립을 위한 지능형 제어 (Intelligent Control for Job Scheduling in Manufacturing)

  • 이창훈;우광방
    • 대한전기학회논문지
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    • 제39권10호
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    • pp.1108-1120
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    • 1990
  • 본 논문에서는 소량 다품종 생산에서 FMS(Flexible Manufactturing System)의 공정제어를 위한 지능형 제어기를 설계하였다. 설계된 제어기는 최적화 기법과 경험적 생산 규칙을 통합하여 가공품의 적재 및 흐름이 제어되고 선정된 성능 평가 기준 지표를 최대로 만족할 수 있도록 한다. 최적화 기법에 의해 구현되는 제어 기능은 생산시스템의 가공용량을 초과하지 않는 범위내에서 가공품의 순시생산율을 계산한다. 생산규칙 구성에 따르는 경험적 제어를 위하여 지식베이스가 형성되고 순시생산율 및 현재의 공정 정보를 기반으로 최종 대안이 선정된다. 이 경우 지식 베이스에는 대안 심사, 결정수립 기준, 그리고 가공품의 흐름제어에 관한 규칙들을 대상으로, 그리고 데이타베이스는 공정 정보 관리, 수정 침 저장을 대상으로 각각 구축된다. 공정 정보를 이용하여 생산계획의 진행 상황을 도시하게 되는 글래픽 시뮬레이션이 수행되며, 설계된 제어기의 성능평가는 컴퓨터 시물레이션을 통해 검토된다.

QUALITY CONTROL OF GINSENG PREPARATIONS BY MEANS OF HPLC: A SAFE METHOD FOR THE PHARMACEUTICAL INDUSTRY

  • Ruckert K.H.
    • 고려인삼학회:학술대회논문집
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    • 고려인삼학회 1980년도 학술대회지
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    • pp.217-222
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    • 1980
  • By means of numerous examples the practical possibility is demonstrated, which HPLC offers at the quality control of Ginseng-preparations. The method is not only suitable for quali-quantitative evaluation of finished products, but also for in-process controls at production of Ginseng specialities. From the examination of various German products which are on the European market, it results, that the contents of Ginsenosides fluctuate strongly. The mechanisms are shown, which could cause destruction of the Ginsenosides at the processing of Ginseng roots. The guiding principles for the production of standardized Ginseng preparations are defined.

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Self-Tuning PID Controller Based on PLC

  • Phonphithak, A.;Pannil, P.;Suesut, T.;Masuchun, R.;Julsereewong, P.
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2004년도 ICCAS
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    • pp.272-276
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    • 2004
  • The conventional PID (Proportional-Integral-Derivative) control technique is widely used for the process control in many industries since it is simple in structure and provides the good response. Nowadays, this control technique has been developed on the Programmable Logic Controller (PLC) to use for the process control loop. However, using this technique is difficult when tuning the PID parameters ($K_p$, $T_i$ and $T_d$) to achieve the best response. Moreover, trial-and-error procedure along with the operator experiences are required to obtain the best results when tuning the PID controller parameters. This paper proposes the self-tuning PID controller based on PLC for the process control in the industries. The proposed self-tuning PID controller uses the PLC-based PID structures to control the process production. The proposed PID tuning utilizes the PLC to synthesize and analyze controller parameter as well as to tune for appropriate parameters using Dahlin method and extrapolation. Experimental results using a self-tuning PID controller to control temperature of the oven show that the controller developed is capable of controlling the process very effectively and provides a good response.

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