• Title/Summary/Keyword: control performance sampling rate selection

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Performance Analysis of Multirate LQG Control (멀티레이트 LQG 제어 기법의 성능 비교 분석)

  • 이진우;오준호
    • Journal of Institute of Control, Robotics and Systems
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    • v.5 no.2
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    • pp.123-130
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    • 1999
  • In discrete-time controlled system, sampling time is one of the critical parameters for control performance. It is useful to employ different sampling rates into the system considering the feasibility of measuring system or actuating system. The systems with the different sampling rates in their input and output channels are named multirate system. Even though the original continuous-time system is time-invariant, it is realized as time-varying state equation depending on multirate sampling mechanism. By means of the augmentation of the inputs and the outputs over one period, the time-varying system equation can be constructed into the time-invariant equation. The two multirate formulations have some trade-offs in the simplicity to construct the controller, the control performance. It is good issue to determine the suitable formulation in consideration of performance of them. In this paper, the two categories of multirate formulations will be compared in terms of the linear quadratic (LQ) cost function. The results are used to select the multirate formulation and the sampling rates suitable to the desired control performance.

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Sensing Parameter Selection Strategy for Ultra-low-power Micro-servosystem Identification (초저전력 마이크로 서보시스템의 모델식별을 위한 계측 파라미터 선정 기법)

  • Hahn, Bongsu
    • Journal of Institute of Control, Robotics and Systems
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    • v.20 no.8
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    • pp.849-853
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    • 2014
  • In micro-scale electromechanical systems, the power to perform accurate position sensing often greatly exceeds the power needed to generate motion. This paper explores the implications of sampling rate and amplifier noise density selection on the performance of a system identification algorithm using a capacitive sensing circuit. Specific performance objectives are to minimize or limit convergence rate and power consumption to identify the dynamics of a rotary micro-stage. A rearrangement of the conventional recursive least-squares identification algorithm is performed to make operating cost an explicit function of sensor design parameters. It is observed that there is a strong dependence of convergence rate and error on the sampling rate, while energy dependence is driven by error that may be tolerated in the final identified parameters.

Generalized predictive control with feedforward and input constraints (입력제약과 선행신호를 고려한 일반형 예측제어기법)

  • 박상현;김창희;이상정
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.327-330
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    • 1996
  • It is well known that the controller output limits have a signifiant effect on the closed loop system performance. Considering the input constraints in GPCF, an effective selection method of the control weighting(.gamma.) is proposed to reduce the amplitude and the rate of control signals so that control signals lie within the limits. It is based on the relation between control weighting(.gamma.) and optimal solution of the unconstrained GPCF. The GPCFIC algorithm chooses an .gamma. at each sampling time so that all unconstrained GPCF output over the control horizon satisfy the rate and the amplitude constraints. In order to evaluate the performance of the GPCFIC, the computer simulations have been done for level control of PWR steam generator in low power operation and shown satisfactory results.

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Identifying differentially expressed genes using the Polya urn scheme

  • Saraiva, Erlandson Ferreira;Suzuki, Adriano Kamimura;Milan, Luis Aparecido
    • Communications for Statistical Applications and Methods
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    • v.24 no.6
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    • pp.627-640
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    • 2017
  • A common interest in gene expression data analysis is to identify genes that present significant changes in expression levels among biological experimental conditions. In this paper, we develop a Bayesian approach to make a gene-by-gene comparison in the case with a control and more than one treatment experimental condition. The proposed approach is within a Bayesian framework with a Dirichlet process prior. The comparison procedure is based on a model selection procedure developed using the discreteness of the Dirichlet process and its representation via Polya urn scheme. The posterior probabilities for models considered are calculated using a Gibbs sampling algorithm. A numerical simulation study is conducted to understand and compare the performance of the proposed method in relation to usual methods based on analysis of variance (ANOVA) followed by a Tukey test. The comparison among methods is made in terms of a true positive rate and false discovery rate. We find that proposed method outperforms the other methods based on ANOVA followed by a Tukey test. We also apply the methodologies to a publicly available data set on Plasmodium falciparum protein.

The Separation of NTSC Signal Components by Using Adaptive Selection Method of Horizontal and Vertical Filters (수평 및 수직 필터의 적응적 선택에 의한 NTSC 칼라영상신호의 성분분리)

  • 권병헌;황병원
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.2
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    • pp.211-224
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    • 1994
  • In this paper, a multi-level adaptive intraframe method has been proposed to separate the luminance and chominance components in NTSC composite signal. The control signals are generated by detecting the vertical correlation and transition in the horizontal and diagonal directions. The chrominance component is adaptively processed through vertical and horizontal filters according to the control signals and the luminance component is processed by subtracting the chrominance component from the composite video signal. The several filters have been used at the sampling rate of four times the color subcarrier frequency and computer simulation and SVP(Serial Video Processing) system have been introduced to compare the performance of the conventional methods and that of proposed one.

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