Transactions of the Society of Instrument and Control Engineers
Online ISSN : 1883-8189
Print ISSN : 0453-4654
ISSN-L : 0453-4654
Volume 14, Issue 2
Displaying 1-19 of 19 articles from this issue
  • Hisato KOBAYASHI, Etsujiro SHIMEMURA
    1978 Volume 14 Issue 2 Pages 107-110
    Published: April 30, 1978
    Released on J-STAGE: March 27, 2009
    JOURNAL FREE ACCESS
    This paper deals with a stability problem of a bilinear system described by x=Ax+Bxu, which arises in the study of an observer and controllability of bilinear systems. The condition under which the system is asymptotically stable in the large independent of the input u is discussed. A necessary condition and a sufficient condition in terms of matrices A and B are derived. And it is shown that this sufficient condition is also necessary for a single-input two-dimensional system to be stable. Another sufficient condition, which can be easily verified, is given for the single-input system.
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  • Tomiji HISAMURA, Hidetaka NAKAO
    1978 Volume 14 Issue 2 Pages 111-115
    Published: April 30, 1978
    Released on J-STAGE: March 27, 2009
    JOURNAL FREE ACCESS
    In this paper, we treat a problem of decoupling a linear, time-invariant multivariable system into single input-multioutput subsystems by means of an output feedback. Necessary and sufficient conditions are derived in the frequency domain. The conditions suggest a new method for constructing a constant feedback matrix, some of whose elements can be freely chosen to reassign closed-loop poles of the decoupled systems. Further, some properties of the feedback matrix are also analyzed.
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  • Hisaaki NAGASE, Yoshiyuki SAKAWA
    1978 Volume 14 Issue 2 Pages 116-121
    Published: April 30, 1978
    Released on J-STAGE: March 27, 2009
    JOURNAL FREE ACCESS
    The continuum model of traffic flow has been used in the analysis of the traffic flow on highways. In this paper this model is applied to the traffic flow controlled by signals on urban streets. First, the basic nonlinear equation which governs the traffic flow is derived, then it is transformed to a heat conduction equation under a suitable nonlinear transformation.
    On a one-way road, we consider a section between two traffic signals which have a common cycle time. In a steady state, the traffic density distribution changes periodically. For calculating this periodic distribution an algorithm is proposed, where the input flow at the first signal and the parameter values of the second signal are assumed to be given. In the algorithm an initial-boundary value problem of the heat conduction equation is repeatedly solved. By comparing the distributions obtained for the various offset values, the optimal offset is determined. Some numerical examples are also shown.
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  • Atsuhiko NODA, Akira HATANO
    1978 Volume 14 Issue 2 Pages 122-129
    Published: April 30, 1978
    Released on J-STAGE: March 27, 2009
    JOURNAL FREE ACCESS
    An optimal method is proposed for system identification. This method is based on the principle of causality and includes an algorithm of the learning identification method.
    In this method, a generalized weighting function model with a pseudo-predictive portion (PPP) is used. This PPP is a weighting function with negative delays and the main portion (MP) is an ordinary weighting function with positive delays. The PPP accuracy can be exactly calculated through the law of causality, and it has been shown that the PPP accuracy is quite useful to estimate the MP accuracy.
    Ordinarily it is impossible to estimate the optimal error-correcting coefficient αjop at the time j. However, this estimated MP accuracy has made it possible to calculate an estimate αj of αjop at the time j. This optimal error-correcting coefficient may settle the trade-off problem between the shortening of the transient state and the improvement of the limit-accuracy. Therefore, this novel method, which will be referred to as a causality optimal method, will perform a practically optimal approximation by using αj at each step of the iteration.
    In addition, this algorithm is simple enough for use in a real time identification.
    Some characteristics of the algorithm have been investigated by theoretical analysis as well as by numerical simulations with a digital computer.
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  • Akio ENDO
    1978 Volume 14 Issue 2 Pages 130-135
    Published: April 30, 1978
    Released on J-STAGE: March 27, 2009
    JOURNAL FREE ACCESS
    In this paper, I propose the modified GMDH algorithm. The GMDH was developed in USSR, and recently regarded as a very useful method. The reason is that it is very easy to use and applicable to model complex systems and with insufficient data. On the other hand, the obtained model with GMDH has usually too high a degree of nonlinearity, and the termination of modeling is vague. So the result is usually unstable. For example, when the input signal is varied in a wide frequency band or made to have a large amplitude, the simulation results become unreliable.
    The modified GMDH preserves the desirable features of GMDH, and institutes the termination criterion in the modeling. The main concepts of this algorithm are the structural stability and the parametric stability which are defined as follows.
    Structural stability: At first, we divide the data to two sets. In one data set, we make the regression analysis. With the obtained model, we make the prediction for the other data set, and get the mean square of the residual. Then we exchange the roles of the data sets. We get the mean square of the residual in the same manner. We consider the obtained model as structurally stable when the sum of the mean square of the residual is small.
    Parametric stability: When the regression coefficients of some term are similar for each data set, the term is considered as parametrically stable.
    The hypothesis which is used in this paper is that the essence of the system is brought by structural stable polynomials which consist of parametrically stable terms. The results of the modified GMDH are presented in computer simulations and in the convergency of identification. I am sure that this method is very practical in analyzing various systems.
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  • Yoshifumi SUNAHARA, Akira OHSUMI, Masaaki ITO
    1978 Volume 14 Issue 2 Pages 136-143
    Published: April 30, 1978
    Released on J-STAGE: March 27, 2009
    JOURNAL FREE ACCESS
    The purpose of this paper is to establish a possible method of control for a class of largescale linear stochastic systems by applying the hierarchical system theory.
    First, introducing the interconnection variables, the overall system is decomposed into several subsystems and then a two-level control scheme is formulated. Secondly, three theorems are given to concretely establish the two-level control scheme; the first one verifies the existence of optimal control for the subsystem in the infimal level and the other two verify the existence and uniqueness of optimal coordination variable in the supremal level. Finally, to help understanding of the proposed method, an illustrative example is presented.
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  • Toshio KOJIMA
    1978 Volume 14 Issue 2 Pages 144-148
    Published: April 30, 1978
    Released on J-STAGE: March 27, 2009
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    In the image processing systems such as the measurement system of patterns, the processing of curved figures is important. In the processing we must first translate the input sequence of dots data into an efficient and compact expression.
    H. Freeman has studied the use of the chain code as a model. In this paper, a spline model using 3rd degree B-spline functions is introduced and its modeling procedure is presented. In the chain code model, a curved figure is represented as a sequence of incremental codes of 3 bits and an ordered set of characteristic points in the spline model.
    From the input data, a spline model is made automatically through the initial approximation phase and the iterative local modification phases.
    In the local modification phase, two characteristic points most dominant with respect to the difference between the model and the input data are moved to improve the performance.
    To evaluate the model, an arc and two hand written curves are selected as examples, and the modeling procedure is examined. The comparison between the data length of the above 2 models are also examined.
    By using this modeling procedure, a compact and efficient spline model can be obtained.
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  • Koji ITO, Akira TAKEUCHI, Masami ITO
    1978 Volume 14 Issue 2 Pages 149-154
    Published: April 30, 1978
    Released on J-STAGE: March 27, 2009
    JOURNAL FREE ACCESS
    This paper discusses the tracking behaviors of the human operator in self-paced preview control systems, in which the operator sees a limited length of his course ahead and modulates continuously the driving velocity according to the variation in the course given as an input function. The following preview control model is proposed: i) The preview input function in space Yd(X) is transformed into a function in time Yd(τ) by utilizing the instantaneous velocity. ii) Next, the present desired input Yd(t) and desired velocity Vd(t) are defined in terms of two kinds of convolution integrals which operate on the future input Yd(τ). iii) Yd(t) and Vd(t) are independently followed by ordinary servomechanisms.
    The preview control model is simulated and the time scores are compared with response of the human operator.
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  • Tokuji OKADA
    1978 Volume 14 Issue 2 Pages 155-162
    Published: April 30, 1978
    Released on J-STAGE: March 27, 2009
    JOURNAL FREE ACCESS
    In this paper, a force control of an artificial finger is described. Force transmitting with a wire which runs through a helical hose is very effective to make a compact and complicated finger driving system since the wire is guided in the hose and the route of force transmission can be selected freely. Because of the friction caused between the wire and hose, the force is not transmitted fully to the output. This friction effect is dealt with in the paper.
    In the first part, given is the discussion for the force control servo system with a negative feedback loop using voltage drop of a small-valued resistance inserted in a armature circuit of D. C. motor.
    In the second part, some factors affecting the magnitude of friction are considered. And the quantitative analysis of friction is given by solving iterative equations among these factors. An equation of dynamical motion of the wire obtained from the analysis clearly explains the nonlinear characteristics in the force transmitting system. The output torque of the motor is grouped into two types; namely the active type and passive type corresponding to the types of the finger's action on an object. In each case, the force controlling method little affected by the friction is established.
    In the last part, descrived is the removal of the dead zone of the force control system by means of a dither signal of which the amplitude is proportional to the tension of the wire, for the correct control of the output force.
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  • Etsuji YAMAMOTO, Yoshifumi YAMADA, Zen-uemon ABE
    1978 Volume 14 Issue 2 Pages 163-170
    Published: April 30, 1978
    Released on J-STAGE: March 27, 2009
    JOURNAL FREE ACCESS
    Previously we proposed a new application of NMR to measure biological materials in human body noninvasively, using the magnetic focusing technique on the measuring target (MT).
    The present paper considers how to generate the magnetic focus and demonstrates this technique by using the low-field NMR spectrometer.
    In the first parts of this paper, the signal error due to the fringe region of MT is evaluated theoretically and the constant field contours for several arrangements of multiple coils are calculated so as to generate the magnetic focus.
    Simple results are obtained analytically for the axisymmetric field especially. Furthermore, a new approach which enlarges the zero-flux region is proposed to achieve a high S/N ratio.
    In the latter parts, the construction of 100kHz NMR spectrometer, whose static field H0 is generated by the main solenoid 70cm long and 40cm in diameter with two compensation windings, is described. The proton resonance signals from 1cm3 sample water are obtained with a S/N ratio of 15, which is more than ten times better than the value estimated from the relation S/N∝H02/3.
    By using the separate samples under the gradient field, a separate signal corresponding quantitatively to each sample is obtained. The signal from a certain specified area near the surface of a large sample has a shifted resonant frequency and an emphasized magnitude when the magnetic focusing technique is applied.
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  • Jiro OHNO
    1978 Volume 14 Issue 2 Pages 171-177
    Published: April 30, 1978
    Released on J-STAGE: March 27, 2009
    JOURNAL FREE ACCESS
    In this paper, a new method for measuring the temperature distribution using multi-spectral radiance is described. An optical thermometry for small hot area, such as a welding point, is different from an ordinary method. Because of the sharp temperature distribution, it is impossible to assign it a single valued temperature. A measurement of the temperature distribution is essential.
    The principle of this method is as follows. The field of view of a radiant sensor covers the target, and the radiant energy from it is measured with multi-wavelengths. The temperature distribution in the field of view can be calculated by the measured multispectral radiance. The temperature distribution x(T) is defined as dS/dT, where S denotes an area of the temperature T. Relation between the spectral distribution of the radiant energy and the temperature distribution is expressed as the 1st kind Fredholm type integral equation. To solve the integral equation, the author proposes an iterative method using a Dynamic Programming approach.
    Computer simulation is carried out to examine this algorithm, especially to examine how the spectral range and emissivities affect the measuring accuracy. In case of a smooth x(T), this algorithm provides strongly convergent result.
    The validity of this method is examined by the following measurement. The temperature distribution of a globar is measured and it is compared with the distribution calculated from the observed radiant energy. Good agreement is obtained between the both distributions.
    This method proposes a unique standpoint in the optical thermometry to utilize multispectral radiance.
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  • Shoji IIDA, Hitoshi ARAKI, Minoru ODA, Yoshihiro MATSUNAGA, Yuji YOSHI ...
    1978 Volume 14 Issue 2 Pages 178-183
    Published: April 30, 1978
    Released on J-STAGE: March 27, 2009
    JOURNAL FREE ACCESS
    This paper describes an ultra-sonic flow meter (U.S. FM) designed to measure coolant flow rate of the fast breeder reactor power plant. The coolant is high temperature liquid sodium, the U.S. FM was improved to be useful in the high temperature environment. First, to eliminate the high temperature influence of the pipe to transducers, the guide rods were used. Second, the electronic circuits were improved to measure the flow rate by the difference in the transmission time of signals. Third, the electronic circuits were endowed with a capability of automatic temperature compensation and protected against bubble disturbance. With the improved U.S. FM, a study of acoustic transmission in liquid sodium was carried out. It was found that the sonic property of liquid sodium is similar to that of water. The U.S. FM was tested in a water flow to exhibit its operational characteristics including the linearity, the time constant and the bubble influence. The results showed up as expected and confirmed the promising aspects of the present measuring method.
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  • Kamekichi SHIBA, Koichiro DOI, Mitsugu OISHI
    1978 Volume 14 Issue 2 Pages 184-188
    Published: April 30, 1978
    Released on J-STAGE: March 27, 2009
    JOURNAL FREE ACCESS
    In the shunt flowmeter, an inferential meter is used as an integrator for a differential pressure flowmeter. The shunt flowmeter is based on the experimentally recognized fact that the pressure drop through a flowmeter of propeller type is approximately proportional to the square of the flow rate.
    In the method, here reported, an auxiliary pipe line is used to integrate the flow rate. It may be either a separate pipe line or a bypass of the main. The flow rate of the auxiliary pipe line is so controlled that the ratio of the flow rate of the main to that of the auxiliary is kept constant all the time. The total flow of the auxiliary pipe line is measured by a positive displacement meter inserted in the line. Then the total flow of the main line is obtained from that of the auxiliary line and the ratio of the flow rates.
    The advantages of this method are as follows:
    (1) As the flow rate of the auxiliary line is controlled to be proportional to that of the main line, the ratio of the flow rates is always maintained exactly constant. Therefore the total flow of the main line is known with a high accuracy.
    (2) If the liquid of the main flow being unsuitable to branch into the auxiliary line, the measurement is performed by using another adequate liquid flow through the auxiliary line, because the auxiliary may be equipped separately from the main.
    (3) When similar differential pressure flowmeters are used in the main and auxiliary line, the discharge coefficient needs not be determined experimentally, for the discharge coefficients of the meters cancel with each other in the expression of the ratio of flow rates.
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  • Akira KOBAYASHI, Tsutomu SHIBATA
    1978 Volume 14 Issue 2 Pages 189-195
    Published: April 30, 1978
    Released on J-STAGE: March 27, 2009
    JOURNAL FREE ACCESS
    In this paper, the authors propose a new nonmetrical algorithm to construct an interval scale from the numerical data obtained by paired comparisons. In the algorithm, the band function model is introduced, and, with respect to the function's average characteristics, a monotone increasing relation is assumed between the numerical data and the difference of a psychological scale on the attribute of the compared objects.
    The algorithm to construct an interval scale is based on an iterative method of calculus, and has the following advantages.
    1) Not necessarily all results about the comparison of each pair of objects are required.
    2) The amount of fazziness or scattering included in the results of the paired comparisons can be known from the width of the dead zone introduced in the algorithm.
    3) An interval scale can be constructed more precisely by this algorithm than by a usual paired comparison method.
    Through the numerical experiments using artificial data, the fundamental characteristics of the algorithm are examined.
    For testing its practical utility, a case of subjective comparisons of weights by human hands is taken up as an example, and the algorithm is applied to reconstructing their real weights. The reconstructed weights show good agreement with the real weights measured by a direct balance.
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  • Effects of Applied Sound on Velocity Profiles
    Ichiro KIMURA, Masatada YONEMOCHI
    1978 Volume 14 Issue 2 Pages 196-201
    Published: April 30, 1978
    Released on J-STAGE: March 27, 2009
    JOURNAL FREE ACCESS
    The effects of sound on air jets have been studied by many researchers, but the behaviour of two-dimensional water jets sensitive to sound, which is especially important for the application of fluidics in oceanography, has not yet been clarified.
    In this study, the authors investigated experimentally the fundamental behaviour of a two-dimensional water jet affected by sound, to find out the exact jet-sound relationships. The jet profile variables including the centerline velocity, the jet width, and the velocity distribution of the jet were measured with a hot film anemometer. Especially, the tendency of the velocity distribution of the jet was compared with Görtler's model.
    The following facts were confirmed:
    1) A water jet becomes sound-sensitive when both its Reynolds number and the frequency of sound are within some bounds.
    2) When a sound of certain frequency is applied, the jet centerline velocity increases but the velocity in the outer shear layer decreases. In this case, a sound-sensitive jet has a responsive frequency bandwidth involving the maximum value of centerline velocities which shifts towards a higher frequency with an increase in the Reynolds number.
    3) The tendency of the spread parameter shows that such changes in the velocity profile with the application of sound are related to the abrupt spreading of the jet following the transition from a laminar domain to a turbulent domain.
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  • Fuminori KOBAYASHI, Michio NAKANO
    1978 Volume 14 Issue 2 Pages 202-207
    Published: April 30, 1978
    Released on J-STAGE: March 27, 2009
    JOURNAL FREE ACCESS
    A harmonic analyzer which furnishes accurate information on the phases of harmonics is proposed. The operating principles of this harmonic analyzer consist in performing compute operations on function f(t) of interest in terms of analog voltage for the Fourier coefficients, using quadrature harmonic sinewaves that are generated in phase with the fundamental of f(t) by two phase-locked oscillators arranged tandem. Thus a d. c. voltage proportional to the real or imaginary part of each harmonic component of f(t) can be obtained. The configuration used in the harmonic analyzer provides a high flexibility in analysis and allows a perfect real-time operation as well. The test run with a prototype consisting of about 35 logic and analog ICs indicated an accuracy of ±0.6% FS over the covered frequency range of 1Hz to 50kHz. A closed-loop version which was implemented by a kind of null method is also discussed. This version not only reduces errors by half but can find use in such applications as filtering devices, e. g., tracking band-pass/notch filters, and high-speed distortion meters.
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  • Tomonori ASHIDA, Masao IKEDA
    1978 Volume 14 Issue 2 Pages 208-209
    Published: April 30, 1978
    Released on J-STAGE: March 27, 2009
    JOURNAL FREE ACCESS
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  • Masaki TAKAMOTO, Kin-ichi KOMIYA
    1978 Volume 14 Issue 2 Pages 210-211
    Published: April 30, 1978
    Released on J-STAGE: March 27, 2009
    JOURNAL FREE ACCESS
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  • [in Japanese], [in Japanese], [in Japanese]
    1978 Volume 14 Issue 2 Pages 212-213
    Published: April 30, 1978
    Released on J-STAGE: March 27, 2009
    JOURNAL FREE ACCESS
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