• Title/Summary/Keyword: time delays

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NON-FRAGILE GUARANTEED COST CONTROL OF UNCERTAIN LARGE-SCALE SYSTEMS WITH TIME-VARYING DELAYS

  • Park, Ju-H.
    • Journal of applied mathematics & informatics
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    • v.9 no.1
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    • pp.61-76
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    • 2002
  • The robust non-fragile guaranteed cost control problem is studied in this paper for class of uncertain linear large-scale systems with time-varying delays in subsystem interconnections and given quadratic cost functions. The uncertainty in the system is assumed to be norm-hounded arid time-varying. Also, the state-feedback gains for subsystems of the large-scale system are assumed to have norm-bounded controller gain variations. The problem is to design state feedback control laws such that the closed-loop system is asymptotically stable and the closed-loop cost function value is not more than a specified upper bound far all admissible uncertainties. Sufficient conditions for the existence of such controllers are derived based on the linear matrix inequality (LMI) approach combined with the Lyapunov method. A parameterized characterization of the robust non-fragile guaranteed cost contrellers is 7iven in terms of the feasible solution to a certain LMI. Finally, in order to show the application of the proposed method, a numerical example is included.

Observer-Based Mixed $H_2/H_{\infty}$ Control Design for Linear Systems with Time-Varying Delays: An LMI Approach

  • Karimi, Hamid Reza
    • International Journal of Control, Automation, and Systems
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    • v.6 no.1
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    • pp.1-14
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    • 2008
  • This paper presents a convex optimization method for observer-based mixed $H_2/H_{\infty}$ control design of linear systems with time-varying state, input and output delays. Delay-dependent sufficient conditions for the design of a desired observer-based control are given in terms of linear matrix inequalities (LMIs). An observer-based controller which guarantees asymptotic stability and a mixed $H_2/H_{\infty}$ performance for the closed-loop system of the linear system with time-varying delays is then developed. A Lyapunov-Krasovskii method underlies the observer-based mixed $H_2/H_{\infty}$ control design. A numerical example with simulation results illustrates the effectiveness of the methodology.

A Study on Interconnectioned LAN of Token Ring Network (토큰링 네트워크가 상호 연결된 근거리 통신망에 관한 연구)

  • 이상훈;김경식;강준길
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.17 no.11
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    • pp.1206-1218
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    • 1992
  • Token ring systems which control to switch the data stream of networks by passing the token have been widely used to medium access controls in many ring or bus topology LANs. The system could be modeled for analysis as single-server-multi-queue system of the cyclic service method. These concepts could be expanded to multi-token ring systems interconnected with single ring consisting of bridges implemented simply to be stored and transmitted. In the proposal for the performance analysis of the interconnected token ring system, in has been assumed M/G/1 queueing model that frame arrivals are the Poisson process at each station queue and frame sizes are independently and identically distributed. And the average time delays were analyzed mathematically for arbitrary frame transferred from source station to destination area. The time delay of the frame transmission could be explained as the sum of the average time which the token passed from arbitrary position to source station, such as the waiting time in the source station transferring the previous arrival frames, and the propagation time from source station to interdestinated point. These delays were given as the sum of the duration from inner and outer bridge queues, the time delays from inner and outer bridge queues, and the time from outer bridge queue to destination station. These results were investigated by varing parameters effected to total time delays. In the results, those factors to be effected to dominant the total time delays were increased were in the cases of the high arrival rates and the high ration of destination of the other outerring. The system were shown the time delays increased exponentially in spite of the priority service policy. In order to decreasing the number of outerrings and increasing the number of nodes in backbone relatively, so the systems could be decreased the total delay in the interconnected token ring system.

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Robust Stabilization of Large-Scale Discrete-Time Systems with Time-Delays (시간지연을 갖는 이산시간 대규모 시스템의 강인 안정화)

  • Park, Ju-H.
    • Proceedings of the KIEE Conference
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    • 2000.07d
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    • pp.2293-2295
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    • 2000
  • This paper describes the synthesis of robust decentralized controllers for uncertain large-scale discrete-time systems with time-delays in subsystem interconnections. Based on the Lyapunov method, a sufficient condition for robust stability, is derived in terms of a linear matrix inequality(LMI). The solutions of the LMI can be easily obtained using various efficient convex optimization techniques. A numerical example is given to illustrate the proposed method.

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Delay-dependent $H_{\infty}$ filtering for continuous-time singular systems with multiple state-delays (다중 상태 시간지연을 가지는 연속시간 특이시스템의 지연종속 $H_{\infty}$ 필터링)

  • Kim, Jong-Hae
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.46 no.5
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    • pp.22-28
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    • 2009
  • In this paper, we consider the problem of $H_{\infty}$ filtering for continuous-time singular systems with multiple state-delays. The aim of designed filter is to guarantee regularity, impulse-free, asymptotic stability and $H_{\infty}$ norm bound of filtering error singular system. By establishing a finite sum inequality based on quadratic terms, a new delay-dependent BRL (bounded real lemma) for singular systems with multiple state-delays is derived. Based on the result, the existence condition of $H_{\infty}$ filter and filter design method are proposed in terms of LMI (linear matrix inequality). Finally, a numerical example is provided to show the validity of the design methods.

Synchronization of Chaotic Secure Communication Systems with Interval Time-varying Delays (구간 시변 지연이 존재하는 카오스 보안 통신시스템의 동기화)

  • Kwon, Oh-Min;Park, Ju-Hyun;Lee, Sang-Moon;Park, Myeong-Jin
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.6
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    • pp.1215-1222
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    • 2009
  • In this paper, a method of designing a controller which ensures the synchronization between the transmission and the reception ends of chaotic secure communication systems with interval time-varying delays is proposed. To increase communication security, the transmitted message is encrypted with the techniques of N-shift cipher and public key. And to reduce the conservatism of the stabilization criterion for error dynamic system obtained from the transmitter and receiver, a new Lyapunov-functional and bounding technique are proposed. Through a numerical example, the effectiveness of the proposed method is shown in the chaotic secure communication system.

Reduced variance implicit self-tuning a;gorithm with variable time-delays for robot manipulator (로보트 매니풀레이터의 시변 지연 시간을 고려한 분산 감소 임플리시트 자기동조 알고리즘)

  • 이희진;박민용;이상배
    • 제어로봇시스템학회:학술대회논문집
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    • 1988.10a
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    • pp.12-15
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    • 1988
  • A controller described in this paper is designed for implicit generalised minimum varience controller with variable time delays in which the weighting polynominals are calculated to reduce the output and control signals variances. This paper is based on the fact that the pole-assigment equation may have multiple solutions if the weighting polynominals are not of minimal order. It is shown that the larger order of the weighting polynominals increment the better is the stochastic behavior of the closed-loop system with variable time delays without changs in the deterministic behavior of the system. Based on this theory, the controller is applied to position control of a three-link manipulater with parameter uncertainty.

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Global Regulation of a Class of Nonlinear Systems with Time-varying Delays in the Input and States with Matrix Inequality and Non-predictor Methods (행렬 부등식과 비예측 기법을 이용한 입력과 상태에 시변지연이 있는 비선형 시스템의 전역 안정화)

  • Koo, Min-Sung;Choi, Ho-Lim
    • Journal of Institute of Control, Robotics and Systems
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    • v.22 no.7
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    • pp.491-495
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    • 2016
  • We deal with the regulation problem of nonlinear systems with time-varying delays in both the states and input. A new state feedback controller with dynamic gains is developed based on matrix inequality and non-predictor methods. The proposed control scheme is analyzed using the Razumikhin theorem, and its effectiveness is demonstrated with simulation results.

Traffic Signal Optimization in Case of 4-Leg Intersections using Genetic Algorithm (GA를 이용한 4지 교차로 신호 최적화)

  • Jo, Hoonsun;Choe, Jeong-Sik
    • Proceeding of EDISON Challenge
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    • 2015.03a
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    • pp.527-529
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    • 2015
  • The control delays at signal intersections have proved the source of numerous vehicular and environmental complications. Control delays both directly and indirectly hinder time- and cost-effective driving by extending the duration of time spent on the road and exhausting excessive amounts of fuel. They furthermore cause traffic congestion, thereby raising overall emission levels. It is therefore imperative to reduce control delays in order to achieve time and fuel economy and reduce vehicle-related pollution. The following study accordingly uses genetic algorithms to optimize traffic signals in congested environments.

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Delay-dependent Robust Passivity for Uncertain Neural Networks with Time-varying Delays (시변 지연을 가진 불확실 뉴럴 네트워크에 대한 지연의존 강인 수동성)

  • Kwon, Oh-Min;Park, Ju-Hyun;Lee, Sang-Moon;Cha, En-Jong
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.11
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    • pp.2103-2108
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    • 2011
  • In this paper, the problem of passivity analysis for neural networks with time-varying delays and norm-bounded parameter uncertainties is considered. By constructing a new augmented Lyapunov functional, a new delay-dependent passivity criterion for the network is established in terms of LMIs (linear matrix inequalities) which can be easily solved by various convex optimization algorithms. Two numerical example are included to show the effectiveness of proposed criterion.