• Title/Summary/Keyword: discrete time linear system

Search Result 298, Processing Time 0.028 seconds

Making Robust Stochastic Stabilizer for Uncertain T-S fuzzy Systems with Input Delay (입력지연을 갖는 불확실 T-S 퍼지 시스템의 강인 디지털 확률적 안정화기 설계)

  • 이호재;박진배;김정찬;주영훈
    • Proceedings of the Korean Institute of Intelligent Systems Conference
    • /
    • 2003.05a
    • /
    • pp.321-324
    • /
    • 2003
  • This paper discusses a robust stochastic stabilization of uncertain Takagi-Sugeno (T-S) fuzzy system with Markovian input delay. The finite Markovian process is adopted to model the input delay of the overall control system. It is assumed that the zero and hold devices are used for control input. The continuous-time T-S fuzzy system with the Markovian input delay is discretized for easy handling delay, accordingly, the discretixzd T-S fuzzy system is represented by a uncertain discrete-time T-S fuzy system with jumping parameters. The robust stochastic stabilizibility of the uncertain jump T-S fuzzy system is derived and formulated in terms of linear matrix inequalities (LMIs).

  • PDF

Design of fuzzy digital PI+D controller using simplified indirect inference method (간편 간접추론방법을 이용한 퍼지 디지털 PI+D 제어기의 설계)

  • Chai, Chang-Hyun
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.6 no.1
    • /
    • pp.35-41
    • /
    • 2000
  • This paper describes the design of fuzzy digital PID controller using a simplified indirect inference method. First, the fuzzy digital PID controller is derived from the conventional continuous-time linear digital PID controller,. Then the fuzzification, control-rule base, and defuzzification using SIM in the design of the fuzzy controller are discussed in detail. The resulting controller is a discrete-time fuzzy version of the conventional PID controller, which has the same linear structure, but are nonlinear functions of the input signals. The proposed controller enhances the self-tuning control capability, particularly when the process to be controlled is nonlinear. When the SIIM is applied the fuzzy inference results can be calculated with splitting fuzzy variables into each action component and are determined as the functional form of corresponding variables. So the proposed method has the capability of the high speed inference and adapting with increasing the number of the fuzzy input variables easily. Computer simulation results have demonstrated that the proposed method provides better control performance than the one proposed by D. Misir et al.

  • PDF

A Design Method of Hybrid Analog/Asymmetrical-FIR Pulse-Shaping Filters with an Eye-Opening Control Option against Receiver Timing Jitter

  • Yao, Chia-Yu
    • ETRI Journal
    • /
    • v.32 no.6
    • /
    • pp.911-920
    • /
    • 2010
  • This paper presents a method of designing hybrid analog/asymmetrical square-root (SR) FIR filters. In addition to the conventional frequency domain constraints, the proposed method considers time-domain constraints as well, including the inter-symbol interference (ISI) and the opening of the eye pattern at the receiver output. This paper also reviews a systematic way to find the discrete-time equivalence of analog parts in a band-limited digital communication system. Thus, a phase equalizer can be easily realized to compensate for the nonlinear phase responses of the analog components. With the hybrid analog/SR FIR filter co-design, examples show that using the proposed method can result in a more robust ISI performance in the presence of the receiver clock jitter.

A Study on the Convergence Condition of ILC for Linear Discrete Time Nonminimum Phase Systems (이산 선형 비최소위상 시스템을 위한 반복 학습 제어의 수렴조건에 대한 연구)

  • Bae, Sung-Han;Ahn, Hyun-Sik;Jeong, Gu-Min
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.57 no.1
    • /
    • pp.117-120
    • /
    • 2008
  • This paper investigates the convergence condition of ADILC(iterative learning control with advanced output data) for nonminimum phase systems. ADILC has simple learning structure including both minimum phase and nonminimum phase systems. However, for nonminimum phase systems, the overall time horizon must be considered in input update law. This makes the dimension of convergence condition matrix large. In this paper, a new sufficient condition is proposed to satisfy the convergence condition. Also, it has been shown that this sufficient condition can be satisfied although it is not full impulse response.

On the Convergence of ILC for Linear Discrete Time Nonminimum Phase Systems (이산 선형 시스템에 대한 반복 학습 제어의 수렴성에 대한 연구)

  • Jeong, Gu-Min;Ahn, Hyun-Sik
    • Proceedings of the KIEE Conference
    • /
    • 2006.04a
    • /
    • pp.225-227
    • /
    • 2006
  • This note investigates the convergence condition of ADILC (iterative learning control with advanced output data) for nonminimum phase systems. ADILC has simple learning structure including both minimum phase and nonminimum phase systems. However, for nonminimum phase systems, the overall time horizon must be considered in input update law. This makes the dimension of convergence condition matrix large. In this paper, a new sufficient condition is proposed to satisfy the convergence condition. Also, it has been shown that this sufficient condition can be satisfied although it is not full impulse response.

  • PDF

Stability Analysis of Kalman Filter by Orthonormalized Compressed Measurement

  • Hyung Keun Lee;Jang Gyu Lee
    • KIEE International Transaction on Systems and Control
    • /
    • v.2D no.2
    • /
    • pp.97-107
    • /
    • 2002
  • In this paper, we propose the concept of orthonormalized compressed measurement for the stability analysis of discrete linear time-varying Kalman filters. Unlike previous studies that deal with the homogeneous portion of Kalman filters, the proposed Lyapunov method directly deals with the stochastically-driven system. The orthonorrmalized compressed measurement provides information on the a priori state estimate of the Kalman filter at the k-th step that is propagated from the a posteriori state estimate at the previous block of time. Since the complex multiple-step propagations of a candidate Lyapunov function with process and measurement noises can be simplified to a one-step Lyapunov propagation by the orthonormalized compressed measurement, a stochastic radius of attraction can be derived that would be impractically difficult to obtain by the conventional multiple-step Lyapunov method.

  • PDF

An Efficient Response Analysis Method for a Structural System Using Substructure Modes (부분구조의 모드를 이용한 구조계의 효율적 응답해석)

  • 김형근;박윤식
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.17 no.5
    • /
    • pp.1084-1094
    • /
    • 1993
  • An efficient method for determining forced responses of a general linear structural system in time domain using subtructure modes and Lagrange multipliers is presented. Compared with the conventional mode synthesis methods, the suggested method does not construct the equations of motion of the combined whole structure and thus the modal parameters of the whole structure are not required. Only modal parameters of each substructure and geometric compatibility conditions are needed. Both the loaded interface free-free modes and free interface modes can be employed as the modal bases of each substructure. Recurrence discrete-time state equations based upon state transition matrix are formulated for the transient analysis of a parameter-changing system. It is shown form numerical examples that the suggested method is very accurate and efficient to calculate transient responses compares with the direct numerical integration method.

Enhanced Independent Component Analysis of Temporal Human Expressions Using Hidden Markov model

  • Lee, J.J.;Uddin, Zia;Kim, T.S.
    • 한국HCI학회:학술대회논문집
    • /
    • 2008.02a
    • /
    • pp.487-492
    • /
    • 2008
  • Facial expression recognition is an intensive research area for designing Human Computer Interfaces. In this work, we present a new facial expression recognition system utilizing Enhanced Independent Component Analysis (EICA) for feature extraction and discrete Hidden Markov Model (HMM) for recognition. Our proposed approach for the first time deals with sequential images of emotion-specific facial data analyzed with EICA and recognized with HMM. Performance of our proposed system has been compared to the conventional approaches where Principal and Independent Component Analysis are utilized for feature extraction. Our preliminary results show that our proposed algorithm produces improved recognition rates in comparison to previous works.

  • PDF

Modeling and Multivariable Control of a Novel Multi-Dimensional Levitated Stage with High Precision

  • Hu Tiejun;Kim Won-jong
    • International Journal of Control, Automation, and Systems
    • /
    • v.4 no.1
    • /
    • pp.1-9
    • /
    • 2006
  • This paper presents the modeling and multivariable feedback control of a novel high-precision multi-dimensional positioning stage. This integrated 6-degree-of-freedom. (DOF) motion stage is levitated by three aerostatic bearings and actuated by 3 three-phase synchronous permanent-magnet planar motors (SPMPMs). It can generate all 6-DOF motions with only a single moving part. With the DQ decomposition theory, this positioning stage is modeled as a multi-input multi-output (MIMO) electromechanical system with six inputs (currents) and six outputs (displacements). To achieve high-precision positioning capability, discrete-time integrator-augmented linear-quadratic-regulator (LQR) and reduced-order linearquadratic-Gaussian (LQG) control methodologies are applied. Digital multivariable controllers are designed and implemented on the positioning system, and experimental results are also presented in this paper to demonstrate the stage's dynamic performance.

Automatic reentry of deepsea riser by adaptive control (적응제어에 의한 대수심 라이저의 리엔트리)

  • 남동호
    • Journal of Ocean Engineering and Technology
    • /
    • v.10 no.1
    • /
    • pp.108-118
    • /
    • 1996
  • This paper presents automatic reentry of a deepsea reser by adaptive control. Reentry is one of the major pro blems regarding a deepsea riser. In the reentry operation, the lower end of riser must be accurately positioned over the tarket point on the seabed. But the deepsea riser shows complex elastic response due to flexibility and nonlinearity of the riser dynamics and the required positioning accuracy is high. Moreover, elastic deformation must by controlled for securing structural integrity. In adaptive control, uncertainly known parameters like added mass and drag coefficient in the riser dynamics are identified and control forces at the floating body and the riser are calculated simultaneously. An Adaptive algorithm for MIMO linear discrete time system without requiring a persistent excitation is adopted in this study. The effectiveness of adaptive control logic is tested by numerical simulation and model experiment. The designed control system shows good overall performances, so that the present study can be applied to the control of the deepsea riser.

  • PDF