• Title, Summary, Keyword: System Control

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Position Control of the Pneumatic Excavator System Using Adaptive Sliding Mode Controller (적응슬라이딩 모드 제어기를 이용한 공압굴삭기 시스템의 위치 제어)

  • Lim, Tae-Hyeong;Cheon, Se-Young;Yang, Soon-Yong;Choi, Jeong-Ju
    • Journal of the Korean Society for Precision Engineering
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    • v.24 no.12
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    • pp.82-87
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    • 2007
  • Excavator has been used in wide field since the attachment in the end effect can be changeable according to the purpose of working. However, efficiency of work using excavator mainly depends on an operator's ability. For the purpose of improving the efficiency of work and reducing the fatigue of operator, the automatic excavator system has been researched. In this paper, the tracking control system of each links of excavator is designed before developing the automatic excavator system. In order to apply the tracking control system, the pneumatic excavator system is developed and the tracking control system is applied. For designing the tracking control system, the adaptive sliding mode control algorithm is proposed. The performance of the proposed control system is evaluated through experiments using the pneumatic excavator system.

Development of Neuro-Fuzzy System for Cold Storage Facility (저온저장고의 뉴로-퍼지 제어시스템 개발)

  • 양길모;고학균;홍지향
    • Journal of Biosystems Engineering
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    • v.28 no.2
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    • pp.117-126
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    • 2003
  • This study was conducted to develop precision control system fur cold storage facility that could offer safe storage environment for green grocery. For that reason of neuro-fuzzy control system with learning ability algorithm and single chip neuro-fuzzy micro controller was developed for cold storage facility. Dynamic characteristics and hunting of neuro-fuzzy control system were far superior to on-off and fuzzy control system. Dynamic characteristics of temperature were faster than on-off control system by 1,555 seconds(123% faster) and fuzzy control system by 460 seconds(36.4% faster). When system was arrived at steady state. hunting was ${\pm}$0.5$^{\circ}C$ in on-off control system, ${\pm}$0.4$^{\circ}C$ in fuzzy control system, and ${\pm}$0.3$^{\circ}C$ in neuro-fuzzy control system. Hunting of humidity and wind velocity was also controlled precisely by 70 to 72.5% and 1m/s For storage experiment with onion, characteristics of neuro-fuzzy control system were tested. Dynamic characteristics of neuro-fuzzy control system made cold storage facility conducted precooling ability and minimized hunting.

The Impact of Information System Control and Audit on the Perceived Risk of the Computer Crime in Case of Financial Institutions (정보시스템통제 및 감사가 컴퓨터범죄의 인지된 위험에 미치는 영향: 금융기관을 중심으로)

  • Han, In-Gu;Yun, Jong-Ho
    • Asia pacific journal of information systems
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    • v.5 no.1
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    • pp.112-128
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    • 1995
  • The information system control includes organizational structure, control mechanism, and management tools which contribute to accomplish the goals of information system: asset safeguarding, data integrity, effectiveness, and efficiency. Information system audit is the process to evaluate whether the information system accomplishs the goals. Information system auditor examine the reliability of information system control and suggest recommendations to improve the information system control. Both information system control and information system audit activities contribute to prevent and detect the computer crime for the organization. This paper proposes a causal model of information system control/audit and the perceived risk of computer crime, and tests the model using a survey on 38 financial institutions in Korea. Statistical results show that information system control and audit significantly reduce the computer crime risk perceived by the user group. The general control has a stronger impact than the application control. In addition, it turns out that the greater the deviation between the importance and the actual level of information system control is, the higher the perceived risk of computer crime is.

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Complex Process Control using the Adaptive Neural Fuzzy Inference System

  • Kim, Dong-Hwa
    • 제어로봇시스템학회:학술대회논문집
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    • pp.351-351
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    • 2000
  • Since the heat exchange system, such as the boiler of power plant, gas turbine, and radiator require an application of intelligent control system for a high rate heat efficiency and the efficiency of these systems is depended on the control methods it is important for operator to understand control system of these systems and intelligent control technologies. In order to properly apply control equipment and intelligent technology to these process control systems, it is necessary to understand fuzzy, neural network, genetics, and immune as well as the basic aspects and operation principle of the process that relate control, interrelationships of the process characteristics, and the dynamics that are involved. Generally, since PID controllers are used in these systems it is difficult far engineer to understand both the complex dynamics and the intelligent control method. In this paper, we design an effective experimental system for the intelligent control education and analyze its characteristics through experimental system and each intelligent method to study how they can learn intelligent control system by experiments.

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Control and Development of LonWorks Intelligent Control Module for Water Treatment Facility Based Networked control System

  • Hong, Won-Pyo;Kim, Dong-Hwa
    • 제어로봇시스템학회:학술대회논문집
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    • pp.1757-1762
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    • 2003
  • With distribution industrial control system, the use of low cost to achieve a highly reliable and safe system in real time distributed embedded application is proposed. This developed intelligent node is based on two microcontrollers, one for the execution of the application code, also as master controller for ensuring the real time control & the logic operation with PLD and other for communication task and the easy control execution, i.e., I/O digital input, digital output and interrupting. This paper also presents where the case NCS (Networked control system) with LonTalk protocol is applied for the filtration process control system of a small water treatment plant.

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An Empirical Model for Decoupling Control of a Variable Speed Refrigeration System (가변속 냉동시스템의 비간섭제어를 위한 실험적 모델)

  • Hua, Li;Jeong, S.K.
    • Journal of the Korea Society For Power System Engineering
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    • v.10 no.3
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    • pp.81-87
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    • 2006
  • This paper deals with an empirical model for decoupling control to control the refrigeration system effectively. The conventional control schemes of the system are mainly focused on representative two control methods, superheat control and capacity control. The capacity control is basically conducted to respond partial loading conditions on the purpose of energy saving. The superheat control is mainly carried out to maintain maximum coefficient of performance (COP). In the variable speed refrigeration system, the capacity and the superheat are controlled by inverters and electronic expansion valves respectively for saving energy and improving cost performance. The capacity and superheat can not be controlled independently because of interfering loop when the compressor speed and opening angle electronic expansion valve is varied. Therefore, we suggest decoupling model to eliminate the interfering loop at first. Next, each transfer function in decoupling control model is obtained from number of experiments.

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The Development of Robot Control System for Nuclear Facilities

  • Lee, Sung-Uk;Kim, Chang-Hoi;Jeong, Seong-Ho;Kim, Seung-Ho
    • 제어로봇시스템학회:학술대회논문집
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    • pp.2696-2700
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    • 2003
  • Nuclear robots should be developed for the reduction of radiation exposure, lower man hours, shorter power outage, and also improved worker safety concerns in performing hazardous and dangerous tasks. Among the components of a nuclear robot system, a robot control system equivalent to a human brain is a crucial point because a nuclear robot does not work without a control system. Therefore, in this paper, we will explain the requirements for a robot control system for a nuclear robot from a general point of view and also review the robot control systems of nuclear robots that were developed domestically, to assist a researcher beginning with the design for the control system of nuclear robots. The explained robot control system will be useful to develop the control system for industrial robots, home robots and other robots which are needed for tele-operation and are controlled through the internet.

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Flight Control System Design and Verification Process (비행제어시스템 설계 및 검증 절차)

  • Kim, Chong-Sup
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.8
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    • pp.824-836
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    • 2008
  • Relaxed static stability(RSS) concept has been applied to improve aerodynamic performance of modern version supersonic jet fighter aircraft. Therefore, flight control systems are necessary to stabilize an unstable aircraft, and provides adequate handling qualities and achieve performance enhancements. Standard FCSDVP (Flight Control System Design and Verification Process) is provided to reduce development period of the flight control system. In addition, if this process is employed in developing flight control system, it reduces the trial and error for development and verification of flight control system. This paper addresses the flight control system design and verification process for the RSS aircraft utilizing design goal based on military specifications, linear and nonlinear system design and verification based on universal software, handling quality test based on HILS(Hardware In-the-Loop Simulator) environment, and ground and flight test results to verify aircraft dynamic flight responses.

Adaptive control strategy in electromagnetic levitation system

  • Kim, Seok-Joo;Kim, Jong-Moon;Kweon, Soon-Man;Kim, Kook-Hun;Kim, Yong-Joo
    • 제어로봇시스템학회:학술대회논문집
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    • pp.1337-1342
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    • 1990
  • This paper deals with control system design strategy for electrolmaginetic suspension (E.M.S.) system. For a successful control of E.M.S. system, the nature of E.M.S. system is deeply studied in the view point of non-linear, open-loop unstable, time-varying, non-minimum phase system. To find a special control treatment for E.M.S. system, analyses and simulations for various models are carried out. As one of the successful candidates, adaptive control concept is introduced and sample hardware system using digital signal processor is implemented.

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Robust Stability Condition and Analysis on Steady-State Tracking Errors of Repetitive Control Systems

  • Doh, Tae-Yong;Ryoo, Jung-Rae
    • International Journal of Control, Automation, and Systems
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    • v.6 no.6
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    • pp.960-967
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    • 2008
  • This paper shows that design of a robustly stable repetitive control system is equivalent to that of a feedback control system for an uncertain linear time-invariant system satisfying the well-known robust performance condition. Once a feedback controller is designed to satisfy the robust performance condition, the feedback controller and the repetitive controller using the performance weighting function robustly stabilizes the repetitive control system. It is also shown that we can obtain a steady-state tracking error described in a simple form without time-delay element if the robust stability condition is satisfied for the repetitive control system. Moreover, using this result, a sufficient condition is provided, which ensures that the least upper bound of the steady-state tracking error generated by the repetitive control system is less than or equal to the least upper bound of the steady-state tracking error only by the feedback system.