Steel Science Portal

Transactions of the Institute of Systems, Control and Information Engineers
New Arrival Alert : OFF

You can use this feature after you logged into the site.
Please click the button below.

Log in / Sign up
ONLINE ISSN: 2185-811X
PRINT ISSN: 1342-5668

Transactions of the Institute of Systems, Control and Information Engineers Vol. 1 (1988), No. 2

  • On the Limit Cycles with a Period Not Equal to Sampling Period Multiplied by Integer, in the Sector-type Nonlinear Sampled-data System

    Hayato OHNISHI, Setsuo SAGARA

    pp. 45-52

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up

    DOI:10.5687/iscie.1.45

    Abstract

    This paper extends the concept of the discrete describing function proposed previously for the analysis of sector type nonlinear sampled data control systems. The previously defined functions were only applicable to the signals which have sub-harmonics of sampling frequencies. We remove the restriction on frequencies and make it possible to apply to an arbitrary frequency. All frequencies less than a half of the sampling frequency are divided into many groups.
    For frequencies that belong to the same group, the evaluation of the discrete describing function provides the same region on the complex-plane. Practically, it is enough to consider a few shapes of these regions. Drawing the inverse Nyquist diagram of linear part of the system on the same complex-plane, limit cycles are predicted by the well-known. graphical method.
    To clarify the description, a few examples are given. The simulation results show that our proposed method is useful for predicting limit cycles which have a period not equal to the sampling period multiplied by an integer.

  • Design of Servomechanisms Using Sliding Mode and Quasi-Sliding Mode

    Hiromitsu HIKITA, Hiroshi KUBO, Tadao NARITA

    pp. 53-60

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up

    DOI:10.5687/iscie.1.53

    Abstract

    A method for designing a servomechanism using sliding mode is considered. This servomechanism of which the input-output relation is given by a transfer function is insensitive with respect to disturbances, parameter variations, and nonlinearity. The structure of this servomechanism satisfies the internal model principle. A servo-mechanism is also given which is obtained by quasi-sliding mode based on a continuous control law to avoid chattering. The properties of errors due to the application of the continuous control law are further investigated. It is shown that the design of the servomechanisms can easily extended to that of multivariable servomechanisms. An example is given in order to illustrate the efficiency of the proposed design method.

  • A Design of a Discrete-Time Adaptive Repetitive Control System

    Mitsuaki ISHITOBI, Zenta IWAI, Keiichi HIROMOTO, Mitsushi HINO

    pp. 61-67

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up

    DOI:10.5687/iscie.1.61

    Abstract

    This paper presents an adaptive repetitive control scheme for discrete-time linear systems. The boundedness of input and output signals, and the convergence of the control error are proved.
    A discrete-time repetitive control structure with a specified convergence property for known parameters plants was considered by Shinnaka. However, when plant parameters are not known, the desired convergence speed is not accomplished. Since the algorithm with adaptive mechanism proposed here, is able to achieve the specified convergence rate of the control error for unknown parameters systems, the convergence speed is improved. Simulation examples are shown to confirm the effectiveness of the design scheme presented in this paper.

  • Identification of a Linear System with Switching Parameters by the EM Algorithm

    Masahiro TANAKA, Tohru KATAYAMA

    pp. 68-76

    Bookmark

    You can use this feature after you logged into the site.
    Please click the button below.

    Log in / Sign Up

    DOI:10.5687/iscie.1.68

    Abstract

    We consider the identification problem for a linear system when the variances of the system and/or the observation noises take on two unknown values. It is assumed that the system and observation noises can be represented in terms of Bernoulli sequences and two random variables with specified but unknown variances. We propose an algorithm to simultaneously estimate the unknown variances and the switching parameters by applying the EM (expectation-maximization) algorithm, avoiding non-linear optimizations that arise in the Maximum Likelihood (ML) and the Maximum A Posteriori (MAP) estimations. Several numerical examples are given to illustrate the effectiveness of the present algorithm.
  • © 1988 THE INSTITUTE OF SYSTEMS, CONTROL AND INFORMATION ENGINEERS (ISCIE)

Article Access Ranking

19 Apr. (Last 30 Days)

  1. Three-dimensional Investigations of Non-metallic Inclusions in Stainless Steels before and after Machining ISIJ International Advance Publication
  2. Perspective toward Long-term Global Goal for Carbon Dioxide Mitigation in Steel Industry Tetsu-to-Hagané Vol.105(2019), No.6
  3. Influence of Ore Assimilation and Pore Formation during Sintering on Reduction Behavior of Sintered Ores Tetsu-to-Hagané Vol.107(2021), No.3
  4. Steam Reforming of Methane on Sponge Iron: Influence of Gas Composition on Reaction Rate ISIJ International Vol.61(2020), No.1
  5. Preface to the Special Issue on “Toward Suppression of Hydrogen Absorption and Hydrogen Embrittlement for Steels” ISIJ International Vol.61(2021), No.4
  6. Dissolution Behavior of Mg and Ca from Dolomite Refractory into Al-killed Molten Steel ISIJ International Advance Publication
  7. Effect of Rare Earth Ce on the Morphology and Distribution of Al2O3 Inclusions in High Strength IF Steel Containing Phosphorus during Continuous Casting and Rolling Process ISIJ International Vol.61(2021), No.3
  8. Improvement in Reduction Behavior of Sintered Ores in a Blast Furnace through Injection of Reformed Coke Oven Gas Tetsu-to-Hagané Vol.107(2021), No.4
  9. Rapid Method to Measure Hydrogen Diffusion Coefficient in Metal Using a Multi-sine Wave Signal ISIJ International Vol.61(2021), No.4
  10. Method for Evaluating Hydrogen Embrittlement of High-Strength Steel Sheets Considering Press Formation and Hydrogen Existence State in Steel ISIJ International Vol.61(2021), No.4

Search Phrase Ranking

19 Apr. (Last 30 Days)

  1. blast furnace
  2. coke oven gas injection
  3. blast furnace permeability
  4. blast furnace productivity
  5. slag
  6. ultrasonic inclusion
  7. activity coefficient of ti in liquid iron
  8. continuous casting of electrical steel
  9. deoxygen in liquid iron
  10. electrical steel and continuous casting