• Title/Summary/Keyword: performance index

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A Analysis on the Effect of the Controller Design due to Performance Index (평가지표에 따른 제어기 설계 영향 분석)

  • Yoo, Hang-Youal;Lee, Jung-Kuk;Lee, Keum-Won;Lee, Jun-Mo
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • pp.90-94
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    • 2004
  • Among various modern control theories, PID control has been well used for several decades. PID algorithms needs son tuning methods are used for selecting PID parameters. But in some cases various kinds of performance indices are used instead of well-known tuning rules, and so variable type of performance index must be tested so that controllers, output characteristics and disturbance rejection property meets some specifications. In this paper, linear conbinational type of performance using error signal, time, control input and robustness is used to the PID control of air conditioning system. By the 2 DOF PID parmeters minimizing perfromacne index, controllers, output characteristics and robustness properties are analyzed. Simulations are done with MATLAB m file and mdl files.

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A Tuning Method for I-PD Controller Using Performance Index (평가함수를 이용한 I-PD콘트롤러의 튜닝)

  • 유항열;이정국;이금원;이준모
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • pp.169-172
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    • 2003
  • PID control has been well used for several decade. For PID algorithm, some tuning methods are used and with these parameters, control system is designed. But in some cases various kinds of performance are needed, so variable type of performance index must be utilized so that the designed control system meets the conditions. This paper presents some linear combinational type of performance index and with numerical methods, the PID parameters are obtained. Moreover I-PD type controller is used so that this two degree of freedom controller may give more desirable output characteristics. Simulations are done with MATLAB m file and mdl files.

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A Quantitative Performance Index for an Input Observer (II) - Analysis in Steady-State - (입력관측기의 정량적 성능지표 (II) -정상상태 해석-)

  • Jung, Jong-Chul;Lee, Boem-Suk;Huh, Kun-Soo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.10
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    • pp.2067-2072
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    • 2002
  • The closed-loop state and input observer is a pole-placement type observer and estimates unknown state and input variables simultaneously. Pole-placement type observers may have poor performances with respect to modeling error and sensing bias error. The effects of these ill-conditioning factors must be minimized for the robust performance in designing observers. In this paper, the steady-state performance of the closed-loop state and input observer is investigated quantitatively and is represented as the estimation error bounds. The performance indices are selected from these error bounds and are related to the robustness with respect to modeling errors and sensing bias. By considering both transient and steady-state performance, the main performance index is determined as the condition number of the eigenvector matrix based on $L_2$-norm.

An Optimal Half-Band FIR Filter for Image Pyramied (영상 피라미드를 위한 최적 Half-Band FIR 필터)

  • 박섭형;이상욱
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.25 no.7
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    • pp.826-835
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    • 1988
  • In this paper, we analyze the generation of an image pyramid as a 2-dimensional decimation-interpolation process, and suggest a performance index of FIR filter for decimation and interpolation filter. Until now, most deciamtion and interpolation filters are designed via the approximation of the impulse response of an ideal filter. In this paper, however, we propose a new performance index that minimizes the maximum frequency-weighted mean square error between the desired and the generated interpolated signal, and propose an optimal half-band filter based on the proposed performance index as an example. Some simulation results with real images show that the proposed optimal half-band filter yields a higher PSNR as well as the more preferable image quality, in comparison with other currently used filters with the same computational complexity.

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A Learning Algorithm for Optimal Fuzzy Control Rules (최적의 퍼지제어규칙을 얻기위한 퍼지학습법)

  • Chung, Byeong-Mook
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.2
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    • pp.399-407
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    • 1996
  • A fuzzy learning algorithm to get the optimal fuzzy rules is presented in this paper. The algorithm introduces a reference model to generate a desired output and a performance index funtion instead of the performance index table. The performance index funtion is a cost function based on the error and error-rate between the reference and plant output. The cost function is minimized by a gradient method and the control input is also updated. In this case, the control rules which generate the desired response can be obtained by changing the portion of the error-rate in the cost funtion. In SISO(Single-Input Single- Output)plant, only by the learning delay, it is possible to experss the plant model and to get the desired control rules. In the long run, this algorithm gives us the good control rules with a minimal amount of prior informaiton about the environment.

An analysis of the worst performance index in the interval system (구간 시스템의 최대평가함수 해석)

  • 김우성;김석우;김영철
    • 제어로봇시스템학회:학술대회논문집
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    • pp.984-987
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    • 1996
  • We consider a feedback control system including interval plant where uncertain parameters expressed in the hyperrectangular box X. Here we define the maximum value of the integral of the error(ISE) as the worst performance index(WPI) due to the plant parameter uncertainty. Suppose that the closed loop system retains robust stability and it belongs to type I. Then we show that the WPI occurs only on the exposed edges of Q. In particular, it is also shown that if ISE is a convex function relative to X, the WPI is attained at one of vertices of X. Some examples are given.

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A HYPOTHESIS TESTING PROCEDURE OF ASSESSMENT FOR THE LIFETIME PERFORMANCE INDEX UNDER A GENERAL CLASS OF INVERSE EXPONENTIATED DISTRIBUTIONS WITH PROGRESSIVE TYPE I INTERVAL CENSORING

  • KAYAL, TANMAY;TRIPATHI, YOGESH MANI;WU, SHU-FEI
    • Journal of applied mathematics & informatics
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    • v.37 no.1_2
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    • pp.105-121
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    • 2019
  • One of the main objective of manufacturing industries is to assess the capability performance of different processes. In this paper, we use the lifetime performance index $C_L$ as a criterion to measure larger-the-better type quality characteristic for evaluating the product performance. The lifetimes of products are assumed to follow a general class of inverted exponentiated distributions. We use maximum likelihood estimator to estimate the lifetime performance index under the assumption that data are progressive type I interval censored. We also obtain asymptotic distribution of this estimator. Based on this estimator, a new hypothesis testing procedure is developed with respect to a given lower specification limit. Finally, two numerical examples are discussed in support of the proposed testing procedure.

SOLVING A SYSTEM OF THE NONLINEAR EQUATIONS BY ITERATIVE DYNAMIC PROGRAMMING

  • Effati, S.;Roohparvar, H.
    • Journal of applied mathematics & informatics
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    • v.24 no.1_2
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    • pp.399-409
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    • 2007
  • In this paper we use iterative dynamic programming in the discrete case to solve a wide range of the nonlinear equations systems. First, by defining an error function, we transform the problem to an optimal control problem in discrete case. In using iterative dynamic programming to solve optimal control problems up to now, we have broken up the problem into a number of stages and assumed that the performance index could always be expressed explicitly in terms of the state variables at the last stage. This provided a scheme where we could proceed backwards in a systematic way, carrying out optimization at each stage. Suppose that the performance index can not be expressed in terms of the variables at the last stage only. In other words, suppose the performance index is also a function of controls and variables at the other stages. Then we have a nonseparable optimal control problem. Furthermore, we obtain the path from the initial point up to the approximate solution.

Determination of Optimal Checkpoint Interval for Real-time Control Tasks Considering Performance Index Function (성능 함수를 고려한 실시간 제어 테스크에서의 최적 체크 포인터 구간 선정)

  • Kwak, Seong-Woo;Jung, Young-Joo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.5
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    • pp.875-880
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    • 2008
  • In this paper, a novel method to determine the optimal checkpoint interval for real-time control task is proposed considering its performance degradation according to tasks's execution time. The control task in this paper has a specific sampling period shorter than its deadline. Control performance is degraded as the control task execution time is prolonged across the sampling period and eventually zero when reached to the deadline. A new performance index is defined to represent the performance variation due to the extension of task execution time accompanying rollback fault recovery. The procedure to find the optimal checkpoint interval is addressed and several simulation examples are presented.

Analysis and Case Study of Permanent Magnet Arrays for Eddy Current Brake Systems with a New Performance Index

  • Sainjargal, Surenkhorloo;Byun, Jin-Kyu
    • Journal of Magnetics
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    • v.18 no.3
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    • pp.276-282
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    • 2013
  • In this paper, magnetic flux distributions of several permanent magnet arrays, including Halbach array, are analyzed and compared. Also, braking force characteristics on a moving solid conductor in the eddy current brake systems with such magnet arrays are analyzed. Then, a new performance index taking into account the maximum braking force and the volume of the magnet is introduced for the comparison and case study of permanent magnet arrays. By changing the lengths, magnetization directions and the height of the permanent magnet arrays, a higher braking force per volume of the magnet can be achieved.