• Title/Summary/Keyword: Sequential Control

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Cumulative Sequential Control Charts with Sample Size Bound (표본크기에 제약이 있는 누적 축차관리도)

  • Chang, Young-Soon;Bai, Do-Sun
    • Journal of Korean Institute of Industrial Engineers
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    • v.25 no.4
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    • pp.448-458
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    • 1999
  • This paper proposes sequential control charts with an upper bound on sample size. Existing sequential control charts have no restriction on the number of observations at a sampling point. For situations where sampling and testing an item is time-consuming or expensive, sequential control charts may not be directly applied. When the number of observations in a sampling point reaches the upper bound and there is no out-of-control signal, the proposed cumulative sequential control chart defers the decision to the next sampling point of which starting value is the value of the current statistic. Two Markov chains, inner and outer chains, are used to derive the formulas for evaluating the performance of the proposed chart. It is compared with $\bar{X}$ and cumulative sum control charts with fixed and variable sample sizes. The fast initial response (FIR) feature is studied. Guidelines for the design of the proposed charts are also given.

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A Method of Select Sequence Control by Remote Control in Process Control designed by SFC (SFC로 설계된 공정제어에서 Remote Control에 의한 선택 시퀀스 제어 방법)

  • You, Jeong-Bong
    • Proceedings of the KIEE Conference
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    • 2007.04a
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    • pp.134-136
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    • 2007
  • Sequential Function Chart(SFC) is very easy to grasp the sequential flow of control logic and has the compatability for a maintenance, In process control, when an error is occurred, to execute other routine by force, we control the process by remote control. In this paper, we proposed the method of select sequence control by remote control in process control designed by Sequential Function Chart(SFC).

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A Method of Design for Sequential Control Systems (시이퀀스 제어계통의 설계법)

  • Hwang, Chang-Sun
    • 전기의세계
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    • v.18 no.6
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    • pp.33-45
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    • 1969
  • The purpose of this paper is design the most important part of sequential control systems, that is, command-treatment part, from the signal-transformation point of view. An orderly procedure is developed by which for sequential control systems the experimental design method can be reduced to the rational design method. Important in this procedure are: 1. To make total block diagram of sequential control systems by determining input and output signals of command-treatment part. 2. To partition over-all block diagram by observing each output signal. 3. To design concretely minimum block diagram by using the operational block diagram. By applying the method for partitioning the circuit to the design, the design method for sequential control systems is organized and done rationally without the aid of experiece.

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A study on Development and Application of Sequential Control Algorithm of Ventilation and Air Cleaning System for Improving Indoor Air Quality in School Classroom (학교교실의 실내공기질 개선을 위한 환기장치 및 공기청정기의 연동제어 알고리즘 개발 및 적용 연구)

  • Park, Hwan-Chul;Lee, Dong-Hyeon;Yee, Jurng-Jae
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.36 no.5
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    • pp.187-194
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    • 2020
  • This study presents the energy-saving sequential control algorithm to handle indoor CO2 and PM2.5 for the improvement of the air quality of school classrooms. To solve indoor air quality (IAQ) problems, air cleaning and ventilation systems are mainly used for school classrooms. Although air cleaning is able to collect PM2.5, it is difficult to remove harmful gas substances. The ventilation system is suitable to tackle CO and CO2, the volume ventilation, however, is relatively small. In this paper, to remove CO2 and PM2.5, the pollutant balance equation for improving indoor air quality is reviewed. The sequential control algorithm of the ventilation and air cleaning system with four levels of criteria is introduced for the effective removal of pollutants. The proposed sequential control algorithm confirms that indoor CO2 and PM2.5 can be properly controlled below the standard value. In addition, the sequential operation of air cleaning and ventilation systems has shown significant improvement in IAQ compared to the independent ventilation system operation. Particularly, such systems are efficient when outdoor PM2.5 is high.

A Study on the Internet Control and Monitoring System using an Embedded System (임베디드 시스템을 이용한 인터넷 제어감시 시스템에 관한 연구)

  • Haeng-Choon Chun
    • Journal of Advanced Marine Engineering and Technology
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    • v.28 no.5
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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.

Development of a Programming System for Sequential Control Using a Graphic Organization Language (그래픽 조직 언어를 이용한 순차 제어용 프로그래밍 시스템 개발)

  • Kuk, Kum-Hoan
    • Journal of the Korean Society for Precision Engineering
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    • v.13 no.4
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    • pp.24-33
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    • 1996
  • PLCs are vital components of modern automation systems, which have penetrated into almost every industry. Many industries have a demand for facilitation of PLC programming. In this study, a programning system for sequential control is developed on a personal computer. This programming system consists of two main parts, a GRAFCET editor and a GRAFCET compiler. The GRAFCET editor enables us to model an actual sequential process by a GRAFCET diagram. This GRAFCET editor is developed by the menu-driven method based on specific menus and graphic symbols. The GRAFCET compiler consists of two parts, a GRAFCET parser and a code generator. The possible errors in a drawn GRAFCET diagram are first checked by the GRAFCET parser which generates finally an intermediate code from a verified CRAFCET diagram. Then the intermediate code is converted into a control code of an actual sequential controller by the code generator. To show the usefulness of this programming system, this system is applied to a pneumatically controlled handling robot. For this robot, a Z-80 microprocessor is used as the actual sequential controller.

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Design for Sequential Control System Using Petri Nets with Hierarchical Expression (II) -composition of Sub Petri nets by Bottom up Oriented Method- (페트리네트의 계층화를 통한 시퀀스제어계의 설계(II) -Bottom up에 의한 서브PN의 합성-)

  • 정석권;정영미;유삼상
    • Journal of Ocean Engineering and Technology
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    • v.15 no.4
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    • pp.108-114
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    • 2001
  • Petri nets have been introduced as a powerful analyzing and design tool for the discrete systems such as sequential control systems. However, one of the important problems in its applications is that the model can be analyzed hardly when we deal with large scale systems because of increase of the number of Petri net components. To overcome this problem, some methods for dividing or reducing of Petri net have been suggested. In this paper, an approach for hierarchical expression of Petri net based on Sequential function Chart(SFC) and Bottom Up oriented Mehodology(BUM) is proposed. Especially, some definitions and rules are defined in order to divide and compose sub Petri nets. A measuring tank system will be described as a typical kind of discrete systems and modeled by some sub Petri nets based on the SFC and BUM by the proposed method in this paper.

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Design for Sequential Control System Using Petri Nets with Hierarchical Expession(II) - Composition of Sub Petri nets by Bottom up Oriented Method- (페트리네트의 계층화를 통한 시퀀스제어계의 설계 (II) - Bottom up에 의한 서브PN의 분할과 합성 -)

  • 정석권;정영미;유삼상
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2001.05a
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    • pp.26-31
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    • 2001
  • Petri nets(PN) have been introduced as a poweful analyzing and design tool for the discrete systems such as sequential control systems. However, one of the important problems in its applications is that the model can not be analyzed easily when we deal with large scale systems because of increase of the number of components of the systems. To overcome this problem, some methods for dividing or reducing of PN have been suggested. In this paper, an approach for hierarchical expression of PN based on Sequential Function Chart(SFC) and Bottom Up oriented Mehodology(BUM) is proposed. Especially, some definition and rules are defined in order to divide and compose sub PN. A measuring tank system will be described as a typical kind of discrete systems and modeled by some sub PN based on the SFC and BUM by the proposed method in this paper.

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Design of Sequential System Controller Using Incidence Matrix (접속 행렬을 이용한 순차 시스템 제어기 설계)

  • 전호익;류창근;우광준
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.12 no.1
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    • pp.85-92
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    • 1998
  • In this paper, we design a sequential system controller, which is capable of processing parallel sequence, on the basis of analysis of control specification described by Petri Net with incidence matrix. The sequential system controller consists of input conditioning unit and petri net control unit which is composed of the token control unit and firing unit. The firing unit determines the firing condition of the transfer signal on the basis of the token status of token control unit. By the proposed scheme, we can easily develop and implement the sequential system controller of automated warehousing system, automated transportation system, elevator system, and so on, as it is possible to modify control specification by changing simply the content of incidence matrix ROM and to expand easily functional capacity as the result of modular design.design.

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Development of an Incentive Level Evaluation Technique of Direct Load Control using Sequential Monte Carlo Simulation (몬테카를로 시뮬레이션을 이용한 직접부하제어의 적정 제어지원금 산정기법 재발)

  • 정윤원;박종배;신중린
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.53 no.2
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    • pp.121-128
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    • 2004
  • This paper presents a new approach for determining an accurate incentive levels of Direct Load Control (DLC) program using sequential Monte Carlo Simulation (MCS) techniques. The economic analysis of DLC resources needs to identify the hourly-by-hourly expected energy-not-served resulting from the random outage characteristics of generators as well as to reflect the availability and duration of DLC resources, which results the computational explosion. Therefore, the conventional methods are based on the scenario approaches to reduce the computation time as well as to avoid the complexity of economic studies. In this paper, we have developed a new technique based on the sequential MCS to evaluate the required expected load control amount in each hour and to decide the incentive level satisfying the economic constraints. In addition, the mathematical formulation for DLC programs' economic evaluations are developed. To show the efficiency and effectiveness of the suggested method, the numerical studies have been performed for the modified IEEE reliability test system.