• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.73.6-73
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• 2001

In this paper, we consider a hierarchical decentralized supervisory control of discrete event systems underpartial observation in two-level hierarchical structure since the observability is a practical and general property in modeling of real systems. Hierarchical consistencies of controllability and observability on the hierarchical decentralized supervisory control are investigated and relevant conditions are proposed to ensure such hierarchical consistencies.

• Transactions on Control, Automation and Systems Engineering
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• 제3권1호
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• pp.1-9
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• 2001

The promise of improved productivity and quality has lead to numerous research investigations in machining process monitoring and control. Recent studies have demonstrated that careful attention must be paid to the regulation of multiple process modules within a single operation such that each module performs its function properly and adverse interactions between modules do not occur. This had lead to the development of supervisory control; particularly to the development of methodologies to systemati-cally construct and implement these controllers. However, no research study has investigated the effect of the production environ-ment on the design of supervisor controllers. In this paper, the design of supervisory controllers for various production environ-ment is studied. The design approach given in Landers and Ulsoy(1998) is applied to construct two supervisory machining control-lers that are experimentally implemented in a face milling operation. Comparisons with an experimental implementation without process control illustrate the benefits of utilizing process controllers that are coordinated properly. The results also show that the given design approach may be used to construct supervisory controllers for different types of production environments.

• 대한전기학회논문지:전력기술부문A
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• 제48권9호
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• pp.1112-1118
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• 1999

A major objective of the study is to propose a supervisory control algorithm based on the discrete event dynamic system (DEDS) model and apply it to the automation of nuclear operations. The study is motivated by the suitability of the DEDS model for simulation of man-made control action and the potential of the DEDS based supervisory control algorithm for enhanced licensibility, when implemented in nuclear plants, through design transparency due to strong analytic backgrounds. The DEDS model can analytically show the robust stability of the proposed supervisory controller providing design transpareney for enhanced licensibility when implemented in nuclear operations.

• 한국생산제조학회지
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• 제23권1호
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• pp.38-47
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• 2014

This paper describes the application of discrete event systems theory to the design of an automated laboratory system. Current automated laboratory systems typically consist of several interacting processes that must be carefully sequenced to avoid any possible process conflicts. Discrete Event Systems (DES) theory and Supervisory Control Theory (SCT) can be applied together as effective methods of modeling the system dynamics and designing supervisory controllers to precisely sequence the many processes that such systems might involve. Classical approaches to supervisory controller design tend to result in complex controller structures that are difficult to implement, maintain, and upgrade. In this paper, a new approach to designing supervisory controllers for automated laboratory systems is introduced. This new approach uses a modular controller structure that is easier to implement, maintain, and upgrade, and deals with "state explosion" issues in a novel and efficient way.

• 조명전기설비학회논문지
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• 제17권1호
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• pp.112-115
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• 2003

산업 자동화의 고정밀도에 따라 서보 제어시스템은 강인제어가 요구되고 있다. 그러나 서보 제어시스템이 외란의 영향을 받게 되면 제어시스템의 강인제어는 어렵게 된다. 이에 대한 보완적인 한 방법으로 본 논문에서는 주 제어기(PID)와 미분 관리제어기의 혼합형 제어기법을 제시하였다. 주 제어기는 궤환제어기로서 동작하고, 미분 관리제어기는 외란에 의한 불안정한 상태에서 보조적인 동작을 한다. 미분 관리제어기의 강인성은 전통기의 속도제어에 의해서 확인하였다.

• 제어로봇시스템학회논문지
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• 제16권10호
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• pp.1013-1017
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• 2010

This paper proposes a systematic approach to the rate-based feedback control based on the supervisory control framework for discrete event systems. We design the supervisor to achieve the desired behavior for TCP wireless networks. From the analysis and simulation results, it is shown that the controlled networks guarantee the fair sharing of the available bandwidth and avoid the packet loss caused by the buffer overflow of TCP wireless networks.

• 대한인간공학회지
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• 제4권2호
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• pp.11-15
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• 1985

Nowadays, there are many situations which the conventional control system can't be applied any more (e.g. nuclear waste disposal sites, radioactive laboratories, the deep ocean and the vacuum of the outer space). New control system must be considered such as supervisory control system in those environment. Using computer graphic robot simulation, supervisory control which can cope with this situation is compared to manual control. As a performance measure of these comparisons, task time and task error are used. And task difficulties and time delay are considered as a variation factor. According to the result of this study, supervisory control is superior to manual control generally. Especially in the situation including task difficulties and time delay, the superiority is much greater.

• International Journal of Control, Automation, and Systems
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• 제5권4호
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• pp.463-470
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• 2007

Colored Petri net model which is a model of discrete event systems is considered in this work. A supervisory controller which enforces reversibility and liveness simultaneously is presented. Furthermore, the algorithms, written by pseudo-code, are presented for the supervisory controller design. A program is developed to implement these algorithms.

• 한국생산제조학회지
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• 제8권4호
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• pp.112-122
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• 1999

In realistic control systems the nonlinear saturation attributes of the control actuator due to physical limitations should be taken into account This nonlinear saturation of actuators may cause not only deterioration of the control performance but also a large overshoot during start-up and shut-down. As the overshoot increases the system may become oscillatory unstable. in this paper the supervisor implementation which guarantees good performance for saturation operation and prevents reset wind up is presented, Moreover the sufficient conditions of the stability for saturated system using supervisory control with a dynamic controller are provided in the continuous-time and in the discrete-time domain Numerical example is illustrated to depict the efficiency of supervisory control for a typical satuaurated production-distribution system controlled by a discrete-time dynamic controller and to validate basic results by simulation.

• 제어로봇시스템학회논문지
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• 제16권11호
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• pp.1025-1028
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• 2010

This paper presents a new approach to analyze the stability of dynamic competitive markets within the framework of supervisory control of discrete event systems. A competitive market is representative of free market economy where it is well known that an invisible hand (also referred to as Walrasian auctioneer) always achieves an equilibrium of demand and supply. Upon the framework of supervisory control theory, this paper shows that Walrasian auctioneer is a stabilizing supervisor for a convergent competitive market, however a non-convergent competitive market (e.g. a free market under economic bubble and depression) controlled by Walrasian auctioneer may not be stable.