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Volume 17, Issue 8
Displaying 1-14 of 14 articles from this issue
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Shinzo KITAMURA, Masaru IHARA, Hiroshi TAKENAKA1981 Volume 17 Issue 8 Pages 789-794
Published: November 30, 1981
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA model is presented for a wire-diameter (equivalently, the thickness of insulator) control process. It is shown that the process is described by a set of nonlinear differential-difference equations including a variable time-delay which varies dependently on a state corresponding to the wire velocity.
The stability of the second and third order systems, which correspond to the process with a proportional-type controller, is next analyzed by investigating the boundedness of solutions, the stability of linearized systems and by using digital simulations. The results show that the global stability of relevant systems could be discussed from the stability property of the linearized systems (with a constant time-delay) under the restriction that the wire velocity is always positive.View full abstractDownload PDF (728K) -
Takashi SOEDA, Toshiaki TABUCHI1981 Volume 17 Issue 8 Pages 795-799
Published: November 30, 1981
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper deals with a design method for an adaptive observer which would identify the parameters and estimate the state of unknown single-input single-output discrete-time linear system where the only input-output can be measured. To accelerate the convergence rate of the adaptive observer, a, finite-time settling algorithm is proposed.
The approach taken here is as follows. First the original system is transformed to Kreisselmeier's parametrized representation to separate the parameter identification process and the state estimation process. For the parameter identification, recursive estimator is given first. Then the estimation gain is determined such that the estimation error becomes to zero at some finite time. Once obtained the parameter estimate, the state estimate is obtained by simple manipulation of the parameter estimate. It is shown that the proposed algorithm converges to the true values at the time k=3n-1, where k is the discrete time and n is the order of system. A simulation result for three order system indicates the acceptable performance of the proposed algorithm for the convergence rate.View full abstractDownload PDF (551K) -
Katsumi KOMIYA, Katsuhisa FURUTA1981 Volume 17 Issue 8 Pages 800-805
Published: November 30, 1981
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn case that the state variables of a linear system are not all accessible, it is well known that the use of the observer is effective to estimate the state variables or a linear function of them. When the inputs or the outputs of the system are measured with biases, the observer designed without considering biases gives the biased estimate of the state.
To treat the problem without loosing generality, the biases are considered to be given by the outputs of the known linear free dynamical systems with the unknown initial conditions. However design methods of the observer effective for such biases have not been considered. In order to give the bias free estimate of a linear function of the state of a linear system, we propose a bias free observer whose order is equivalent to the one of the system to be observed, and we present a design method for such a bias free observer.
Especially, the solvability condition of the bias free observer design problem is derived by the direct application of the D. D. P. S. (Disturbance Decoupling Problem with Stability) proposed by Wonham. Moreover, the possibly of the order reduction of the bias free observer is discussed.
The design algorithm of the possibly minimal order bias free observer is similar to the ones of Kimura or Furuta et al., where the possibly minimal order bias free observer is realized by a realization algorithm.View full abstractDownload PDF (709K) -
Kazunori YASUDA, Kazumasa HIRAI1981 Volume 17 Issue 8 Pages 806-812
Published: November 30, 1981
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSLarge-scale systems with time delay are often seen in chemical processes and many other systems. In this paper we consider the problem of stabilizing linear large-scale systems with time delay (LSD) described by differential-difference equations
xi(t)=Aixi(t)+∑Nj=1Fijxj(t)+∑Nj=1Dijxj(t-hij)+biui(t), i=1, 2, …, N,
where Ai, bi are of the companion from, by using local feedback laws
ui(t)=kiTxi(t), i=1, 2, …, N. Such a stabilization problem is studied for linear large-scale systems without time delay (LS) by many researchers, and some sufficient conditions for stablizability are derived in terms of the structure of interconnection matrices Fij.
The objective of this paper is to extend these conditions for LS to LSD. The stabilizability condition obtained here is given as form of the interconnection matrices Fij and Dij to be satisfied, which can be calculated easily by using a computer, and coincide one for LS by setting Dij=0. It should be noted that the conditions obtained here are applicable to LSD whose subsystems are with multi-input, by decomposing each subsystem the set of some single-input systems.View full abstractDownload PDF (763K) -
Atsunobu ICHIKAWA, Shigenobu KOBAYASHI, Takashi YAGI1981 Volume 17 Issue 8 Pages 813-818
Published: November 30, 1981
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSHigh-order correlation matrix associative memory (HCMM) is proposed and examined in this paper.
The conventional correlation matrix associative memory (CMM) so far studied utilizes only the second-order correlation involved in the signals and is not concerned with the third and higher order correlations which might be quite effective for association if utilized. This causes the major draw-back of the CMM, that is, the accuracy of the recall decreases considerably when the signals are linearly dependent. Thus, the memory capasity of the CMM is Iimited not by the number of the memory cells but by the dimension of the signals. This is the great incovenience in the practical use of the associative memory.
The HCMM is introduced to dissolve the drawback of the CMM. Examinations of the HCMM's principle, the correct recall rate to random signals, the memory efficiency and the robustness of the memory for a partial break-down make clear the following preferable properties of the HCMM:
As the order of correlation increases;
- the accuracy, of recall increases when the signals are linearly dependent,
- the memory capacity, increases while keeping the same accuracy of recall.
- the memory capacity per cell decreases,
- the robustness of the memory for a partialb reak-down increases.View full abstractDownload PDF (776K) -
Masaki TOMINAGA, Takeo KINOSITA1981 Volume 17 Issue 8 Pages 819-824
Published: November 30, 1981
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSSoil-water content in the gro an und, which is supplied by rain infiltration, plays an important role in development of natural disaster, such as landslide, failure of slope or dike, etc. These kinds of disaster occur during or after rainfall. Therefore, investigation for mechanisms of these kinds of disaster requires time-continuous or short periodic observation of the change of soil-water content in the ground. For this purpose, electrical methods are available. In the present paper, the relation between the specific resistance of mixed materials and the volume of each material is studied by use of current density, on the reliable hypothesis that, on any closed surface in the mixed material, the ratio of the area occupied by a material to the total area of the closed surface is uniform, for every material. In result, the specific resistance of mixed material is the harmonic mean of the weighted specific resistance of each material. Difficulties are inevitable in the field investigation of the soil-water content, such as disorder of the soil layer and ununiformity of contact between the electrodes and the surrounding soil. As a result of the theoretical consideration, the difficulties mentioned above are eliminated by the ratio between the specific resistance measured at any time and that measured at some time, and the ratio has some available properties in analysis of the time-varying characteristics of soil-water content. Above discussions are confirmed by the experiment which was performed in the experimental field of the National Research Center for Disaster Prevention.View full abstractDownload PDF (843K) -
Tadao KAWAGUCHI, Kenshi KATAYAMA, Katsuhiko KASHIBA1981 Volume 17 Issue 8 Pages 825-830
Published: November 30, 1981
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn the cold rolling of stainless steels on a Sendzimir mill, the shape of strip is very important for guaranteeing the quality of rolled products, the stabilization of operation, the maintenance of operational safety, etc. As products of a wide variety of kinds and sizes, including non-magnetic materials, are rolled at high tension, there had not been any appropriate means of shape detection. So most operations were performed, relying largely upon operator's empirical control practices.
“Batting test”is such a practice in which the edge of strip is struck with an oak stick and the extent of edge elongation and the strip shape are determined from the sound and feeling of batting. For quantitative translation of such practices, studies were repeated using various parameters. These efforts culminated in the development of a sensor employing the vibration frequency of strip which rcflects the actual strip shape in the most reliable manner.
According with this theory, the Frequency Analyzing Shape Detection System is constructed by a batting device and a signal processing device.
The former causes the vibration to the strip and the later analyses the vibration signal and calculates the fatness index by use of two spectrum analyzers and two micro-computers.
As a result of adopting the latest signal processing technology, this detection system provides a detection accuracy within 0.19% at steepness, and have being used successfully in Hikari Works, Nippon Steel Corporation.View full abstractDownload PDF (783K) -
Kiyoaki KIKUCHI, Akira SUZUKI1981 Volume 17 Issue 8 Pages 831-836
Published: November 30, 1981
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a method for measuring very low currents by using the improved condenser charging method. The voltage change during the charging process of the condenser is measured on a fixed time interval by the charge sensitive amplifier and the resulting output pulses are integrated individually. The errors, which arise from a stray capacitance of the input circuit and the charge generated at the contact of the dry-reed switch, could be minimized by this method. This picoammeter has a noise level of as low as 6fA and 2fA when the internal resistance of the current sources are 1010Ω and 1011Ω respectively.View full abstractDownload PDF (1189K) -
Naotake MOHRI, Yasujiro OSHIMA, Changjo YUN1981 Volume 17 Issue 8 Pages 837-843
Published: November 30, 1981
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe authors developed an automatic positioning method for the translational displacement of IC chip by using the holographic technique. One of the biggest problem in this method is the reduction of signal (optical spot) intensity caused by the tilting angles (φ, ψ) about two axes of IC chip plane and the rotating angle (θ) in it's plane. This paper describes one of the methods how to control automatically these attitude angles of IC chip plane.
A laser beam directed normally to the surface of the chip forms a reflection diffraction image which conisists of a pair of straight lines intersecting orthogonally on the optical axis. Then, by finding the point of intersection of these orthogonal lines it is possible to determine two degrees of inclination of the chip. Moreover, the displacement angle within the refraction image will be the unaltered angle of rotation of the chip.
In order to observe these angles, the four photoelectric microscopes are arranged arround a fixed axis and rotated by a stepping motor to provide a circular scan. After computation based on the number of pulses by a minicomputer, the three control stepping motors are driven simultaneously while comparing the pulses count with computation results; at the appropriate time each of the stepping motors is stopped.
We have confirmed that the angular positioning errors can be held within a standard deviation of approximately 20 seconds of arc, for θ, and 1 second of arc, for φ and ψ.
As a result of this, it is found that the optical spot for detection of translational displacement has sufficient intensity for the detection.View full abstractDownload PDF (2627K) -
Hisashi TSURUOKA1981 Volume 17 Issue 8 Pages 844-849
Published: November 30, 1981
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSNon-destructive sugar content and acidity measurement of fruit to serve the automatic grading of fruits in the packing house line is considered. The principle of this measurement is to use the correlation of sugar content or acidity of fruit with its conductivity, both sugar content and acidity affect the conductivity but it may be possible to measure them separately by the utilization of the dispersion phenomenon. This is confirmed by the experimental data on the frequency characteristic of solution of citric acid and sugar.
The conductivity of fruit's fresh is calculated by the following method. The fruit is embedded into electrolytic solution. Electrodes are mounted on the inner wall of the vessel. The distortion of electric field(χ). deffined by the square sum of the voltage difference between the adjoining electrodes is calculated. Under the assumption that the fruit is constituted of the three shells, rind, fresh, core, the conductivity of electrolytic solution is changed three times. From the linear combination of the corresponding χ, the conductivity of fruit's fresh can be determined.
The error of the calculated conductivity of fruit's fresh is evaluated by two dimensional computer simulation. The results obtained are followings. The accuracy of the calculated conductivity of fruit's fresh deppends on the conductivity of rind or fresh and fruit size. But if the variation of fruit size can be compensated through the measurement of fruit size, the error of the calculated conductivity of fruit's fresh can be within 5∼10%, under the ±20% variation of the conductivity of skin or fresh.View full abstractDownload PDF (848K) -
Hideo TAGUCHI, Katsuhiko FUJII1981 Volume 17 Issue 8 Pages 850-857
Published: November 30, 1981
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe various phase of the human adaptation in time-varying control situation has been researched by many control engineers. Putting these efforts together, it is evident that in manual control the human operator can use the qualitative pattern recognition for state variables, as well as the optimization of the quantitative performance.
However, the literature on which the unified model for both the qualitative ability and quantitative ability of the human operator is synthesized is not extensive. Thus, in this paper the human operator is viewed as an versatile controller with the integrated ability, involving. detection, decision, modification and so on.
In our manual task, the human ability is tested with unknown-but-invariant plant dynamics, and also unknown-sudden changes in plant dynamics.
The well-trained operator can predict how the displayed signal will respond to his own control action while tracking. It is reasonable to assume that the detection of changes in plant dynamics is based upon the use of this prediction. If a change is detected, the human operator must select the appropriate control strategy to the new plant dynamics and then modify his characteristics in order to achieve stability and control of the plant.
The experimental results show that the adaptive process of the human operator is achieved by three elements- detection of changes in dynamics, choice of control strategies and modification-. The resulting model is developed for these three elements. That is, the model form includes detection unit, control mode choice unit of pattern recognition type, and dual control unit (i. e., “bang-bang” control strategy and “gradual” one).
Finally, the model is simulated on the digital computer. And the control ability of the model is tested with changes in plant dynamics. The results closely match those of the human operator.View full abstractDownload PDF (1136K) -
Toshitsugu UEDA, Seiki RA1981 Volume 17 Issue 8 Pages 858-864
Published: November 30, 1981
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe displacement transducer described in this paper measures distance as a function of the propagation time of an acoustical pulse travelling from a transmitter past two detector sensors on a magnetostrictive delay line.
Displacements from a few micro meters to a few meters can be measured as analog quantities without any mechanical contact with the object.
Acoustical velocity is generally influenced by temperature, which makes it difficult to realize precise displacement measurements utilizing acoustical waves. To overcome this problem, the authors developed the displacement transducer described in the following paragraphs.
Two detector coils-one fixed on each end of a magnetostrictive delay line-detect acoustical waves which are transmitted by a moving coil installed between them. By measuring and computing the ratio of the propagation times from the moving coil to each detector, the displacement can be obtained.
In this way, the temperature characteristics of the transducer as well as the changes in electro-mechanical (transduction) efficiency of the delay line materials are compensated for and the common mode noise rejection is greatly improved.
This paper describes the basic principles, construction and characteristics of a displacement transducer built as a test model utilizing acoustical wave propagation. Instead of employing conventional slidewire potentiometers, this transducer was installed as a position feedback element in servo recorders owing to the transducer's simple contactless construction and high speed response. Thus, reliable servo recorders were realized by incorporating these contactless displacement transducers.
A unique wireless method was devised to supply current pulses to the movable transmitter coil by magnetic coupling.View full abstractDownload PDF (1884K) -
Takumi NAKAMURA, Takashi SUZUKI1981 Volume 17 Issue 8 Pages 865-867
Published: November 30, 1981
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDownload PDF (336K) -
Osamu KAWAURA1981 Volume 17 Issue 8 Pages 868-869
Published: November 30, 1981
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDownload PDF (222K)
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