• Title/Summary/Keyword: Multi-variable system

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The Control of Large Scale System by Sliding Mode (슬라이딩 모드를 이용한 대규모 계통의 제어)

  • Chun, Hee-Young;Park, Gwi-Tae;Kuo, Chun Ping;Kim, Dong-Sik;Im, Hyeong-Yong
    • Proceedings of the KIEE Conference
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    • 1987.07a
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    • pp.190-194
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    • 1987
  • This paper describes a new method for control of large-scale system by sliding mode. The concepts of control to large-scale system on the basis of VSS(Variable Structure System) control theory are used to decompose a large control problem into a two-level algorithm such that each subsystem is stabilized with local discontinuous controllers and higher level corrective control is designed to take into account the effect of interaction among the subsystems. In this paper, we show that each subsystem is controlled with repect to local continuous and higher level corrective control. This algorithm can be easily applied to multi-variable control system and obtained a continuous control in comparison With variable structure control systems. Two numerical examples are discussed as illustrations.

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Extend DEVS Modeling and Simulation Methodology for Variable Structure Modeling (가변구조 모델링을 위한 확장된 DEVS 모델링 및 시뮬레이션 방법론)

  • 정기찬;이종근;이장세;지승도
    • Journal of the Korea Society for Simulation
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    • v.8 no.4
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    • pp.109-124
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    • 1999
  • The major objective of this research is to design and build the variable structure DEVS modeling & simulation framework. To do this, we have proposed the direct message passing mechanism between the model and its simulator to deal with the structural demand from the model during the simulation. In this approach, four types of basic messages are introduced for the vertical(creation/deletion of the child) and horizontal(creation/deletion of the brother) structural changes. Proposed methodology has been successfully applied to the multi-processor system and the forest fire information system.

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Performance Evaluation of Multi-Phased MC-CD74A System for transmitting the High Rate Data (고속데이터 전송을 위한 Multi-Phased MC-CDMA 시스템의 제안 및 성능 분석)

  • 안철용;안치훈;김동구;류승문
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.26 no.12B
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    • pp.1637-1647
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    • 2001
  • Multi-Code CDMA (MC-CDMA) can not only be integrated easily with a conventional system, but also achieve good spectral efficiency and high processing gain. However, it suffers from high value of peak-to-average power ratio (PAPR). In this paper, we propose the Multi-Phase CDMA (MP-CDMA) system that can provide variable rate service and is not susceptible to the non-linear characteristics of amplifier. The clipping is introduced between at the output of multi-code modulator and at the input of MPSK modulator in order to improve the performance of MPSK chip demodulator and reduce the system complexity, The system performances are compared for the different Number of codes and different clipping levels, respectively. The optimum clipping level is also evaluated for the different number of codes in both, AWGN and frequency flat fading channel.

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An Experimental Study on Multi-Fault Detection and Diagnosis Analysis of HVAC System (HVAC 시스템의 중복고장 검출을 위한 실험적 연구)

  • Cho Sung-Hwan;Hong Young-Ju;Yang Hooncheul;Ahn Byung-Cheon
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.16 no.10
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    • pp.932-941
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    • 2004
  • The objective of this study is to detect the multi-fault of HVAC system using a new pattern classification technique. To classify the effect of single-fault in determining the pattern, supply air temperature, OA-damper, supply fan, and air flowrate were chosen as experimental parameters. The combination of supply temperature, flow rate, supply fan and OA-damper were chosen as multi-fault conditions. Three kinds of patterns were introduced in the analysis of multi-fault problem. To solve multi-fault problem, the new pattern classification technique using residual ratio analysis was introduced to detect the multi-fault as well as single-fault. The residual ratio could diagnose single-fault or multi-fault into several patterns.

The Generator Excitation Control Based on the Quasi-sliding Mode Pseudo-variable Structure Control

  • Hu, Jian;Fu, Lijun
    • Journal of Electrical Engineering and Technology
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    • v.13 no.4
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    • pp.1474-1482
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    • 2018
  • As an essential means of generator voltage regulation, excitation control plays an important role in controlling the stability of the power system. Therefore, the reasonable design of an excitation controller can help improve the system stability. In order to raise the robustness of the generator exciting system under outside interference and parametric perturbation and eliminate chattering in the sliding mode control, this paper presents a generator excitation control based on the quasi-sliding mode pseudo-variable structure control. A mathematical model of the synchronous generator is established by selecting its power, speed and voltage deviation as state variables. Then, according to the existing conditions of the quasi-sliding mode, a quasi-sliding mode pseudo-variable structure controller is designed, and the parameters of the controller are obtained with the method of pole configuration. Simulations show that compared with the existing methods, the proposed method is not only useful for accurate voltage regulation, but also beneficial to improving the robustness of the system at a time when perturbance happens in the system.

Analysis of Multi-Variable Control using Model Based Compensator (Model Based Compensator를 이용한 다변수 제어 분석)

  • Jung, Ji-Hyeon;Lee, Woo-Min;Yoo, Sam-Hyeon;Lee, Chong-Won
    • Proceedings of the KSME Conference
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    • 2000.11a
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    • pp.564-569
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    • 2000
  • Model Based Compensator(MBC) is recently used for the analysis of multi-variable control in frequency domain. Target loop is designed by the demanding requirements such as cross-over frequency, disturbance rejection in low frequency domain, zero steady-state error, identification of maximum and minimum singular values and sensor noise rejection in high frequency domain. Loop transfer recovery will be continued in frequency domain until the plant with MBC comes close to the target loop. In this study, the technique using MBC is applied to the elevator vibration control system. It is found that this technique is very effective to control the vibration system.

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Longitudinal Tension Control at Start and Stop in a Multi-span Continuous Process System (변속시의 멀티 스팬 연속 공정 시스템의 장력제어)

  • 신기현;권순오
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1994.10a
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    • pp.584-589
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    • 1994
  • A time-varying nonlinear mathematical model was derived to consider the effect of change in roll radius on tension varation during winding and unwinding. A variable-gain PID controller was designed for tension control at start and stop in a multi-span continuous process system. The controller gains are updated at every control loop as roll radii continuously change. Computer simulation was carried out by using the mathematical model and the controller developed for a typical operating condition including acceleration and deceleration. When the variable-gain PID controller was used, the tension control performance was improved compared with that of existing control method during start-up and stop.

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GA-based Feed-forward Self-organizing Neural Network Architecture and Its Applications for Multi-variable Nonlinear Process Systems

  • Oh, Sung-Kwun;Park, Ho-Sung;Jeong, Chang-Won;Joo, Su-Chong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.3 no.3
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    • pp.309-330
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    • 2009
  • In this paper, we introduce the architecture of Genetic Algorithm(GA) based Feed-forward Polynomial Neural Networks(PNNs) and discuss a comprehensive design methodology. A conventional PNN consists of Polynomial Neurons, or nodes, located in several layers through a network growth process. In order to generate structurally optimized PNNs, a GA-based design procedure for each layer of the PNN leads to the selection of preferred nodes(PNs) with optimal parameters available within the PNN. To evaluate the performance of the GA-based PNN, experiments are done on a model by applying Medical Imaging System(MIS) data to a multi-variable software process. A comparative analysis shows that the proposed GA-based PNN is modeled with higher accuracy and more superb predictive capability than previously presented intelligent models.

Natural Vibration Characteristics of Multi-step Rotating Shaft (다단 회전축 고유진동 특성)

  • 전오성
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1997.10a
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    • pp.114-119
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    • 1997
  • Natural vibration of the rotor system having multi-step cross-sections is analyzed. The rotary inertia and the shear deformation are considered. Torque is also included in order to simulate the power transmission system. The complex displacement and the variable separation are introduced. The exact solutions in uniform cross-section segment and the boundary conditions are used. Natural frequencies and mode shapes are obtained, especially the mode shapes are countinuous.

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Robust sliding mode control of nonlinear uncertain system via geometric approach (기하학적 접근에 의한 비선형 불확실성 시스템에 대한 강건한 슬라이딩 모드 제어)

  • 박동원;김우철;김정식;최승복
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10a
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    • pp.1213-1218
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    • 1993
  • Variable structure control is applied to the robust output tracking control problem of general nonlinear multi-input multi-output (MIMO) systems. Using the concept of relative degree and minimum phase, input/output(I/O) linearization is undertaken. For I/O the linearized system, a new sliding hyperplanes design method is proposed. In this procedure, we can construct very robust and efficient sliding mode controller for general nonlinear systems of relative degree higher than two. The control results are illustrated by adopting a numerical example.

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