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Volume 4 (1968)
- Issue 4 Pages 313-
- Issue 3 Pages 213-
- Issue 2 Pages 99-
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Volume 4, Issue 4
Displaying 1-16 of 16 articles from this issue
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Kokichi NITTA, Hiroshi OKITSU, Eizi YOSHINARI1968 Volume 4 Issue 4 Pages 313-318
Published: December 30, 1968
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSRecently, the speed control systems using DC motor with thyristor are employed in many industries, since they have many advantages compared with the conventional motor-generator speed control system.
On the other hand, to realize the reversible direction of rotation of the DC motor, we must have the circuit construction which can change the direction of field or armature current.
Various circuits are worked out to accomplish this purpose, for example, the one uses plural thyristor, the other adopts the split-field having the large time constant, the third makes use of the change-over mechanical contact, etc.
In this paper, the reversible speed control system with single thyristor is explained, and it's static and dynamic characteristics are measured and discussed. In this control system, the speed of the DC motor is controlled by the gate signal and the rotational direction of the motor is controlled by the unbalanced current between the direct current and the reverse current discharged from the inductive element in the armature.
The speed-torque characteristics of the above mentioned system is approximately linear and the response time is not so large compared with that of the DC motor drived by DC power supply.View full abstractDownload PDF (717K) -
Yukio MATSUMOTO1968 Volume 4 Issue 4 Pages 319-326
Published: December 30, 1968
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDynamic analysis of natural and forced circulation evaporators is presented in this paper.
Basic differential equations are given which describe the dynamic properties of evaporators by taking into consideration the mass and energy balances of solution, the material balance of solute, etc.. These equations are linearized and Laplace transformed and matrix transfer function is obtained to show dynamic behavior between several inputs and outputs.
As a numerical example, step responses of density, temperature, drum pressure and solution level for condenser flow rate and feed rate variations, etc. are compared in an evaporator of caustic soda.View full abstractDownload PDF (763K) -
Takeshi KAWANISHI, Hisao MARUYAMA1968 Volume 4 Issue 4 Pages 327-332
Published: December 30, 1968
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSFor the statistical treatment of the problems of quality control and reliability, it is essential to consider the normal distribution. This paper reports a normal distribution signal generator (Gaussian pulse generator) and its applications to those problems. From the theoretical analysis, it has become clear that convolution of some kind of distibution functions can be performed by a integrator with suitable pulse delay circuits.
Using the above mentioned technique, a new type Gaussian pulse generator is constructed. As an example of the applications of this device, a method performing convolution of two normal distributions is shown. A circuit for checking agreement between a measured histogram and a theoretical normal distribution is also shown in this paper.View full abstractDownload PDF (746K) -
Minoru HAYASE1968 Volume 4 Issue 4 Pages 333-341
Published: December 30, 1968
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper shows some relation between the matrices (Hurwitz H, Routh R and Liapunov S:=xTSx) for stability criterion and the performance index in the optimum control for linear constant coefficient systems. In the process of this research, some new meanings of H and S, in the view point of optimum control, are investigated.
As a result, it is shown that the relation between H, R and S can be described more compactly than conventional ways. Furthermore, this paper shows the direction of its application, through some examples.View full abstractDownload PDF (907K) -
Noboru TAKAI, Shigeru HATANAKA1968 Volume 4 Issue 4 Pages 342-349
Published: December 30, 1968
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA study on changes of hysteresis characteristic in thermoelectric e.m.f. of Pt vs Pt-Rh 10% thermocouples is described.
The hysteresis changes of thermoelectric power appear mainly on the Pt-Rh 10% element, and are determined by the heating conditions in use, such as heating temperature, heating time, and cooling rate.
Moreover characteristics of the hysteresis vary according to the degree of cold working and the annealing temperature of the element.
The e.m.f. changes caused by the hysteresis are calculated under some practical conditions, and actually confirmed by silver freezing point measurements and intercomparison tests on several thermocouples.
As a result of these trials, an e.m.f variation amounting up to±3μV is found in case of unconditional use, but it is reduced to the order of±0.5 μV by application of a constant heat treatment before every measurement.View full abstractDownload PDF (1083K) -
Kokich NITTA, Hiroshi OKITSU, Takayuki SUZUKI1968 Volume 4 Issue 4 Pages 350-356
Published: December 30, 1968
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe control systems are classified into two large groups, that is, DC control systems and AC control systems. On the other hand, the compensating circuits adopted to these control systems are grouped into three classes, the phase lead, the phase lag, and the phase lag-lead circuit.
In general, these compensating circuits consist of several resistors and capacitors, but the rotating machines are used for this purpose in our seminar for the past ten years. One of the compensating devices to the DC control system consists of a resistor and a separately excited DC motor, and the other consists of a separately excited DC generator and a potentiometer.
On the above mentioned DC compensating devices, various papers on their principles and dynamic characteristics by us. were published some years ago describing.
And so, in this paper the principle, the characteristics, and it's analysis of the AC compensating device, which consist of a two-phase servomotor and a two-phase rate generator were described.
The merits of this device are as follows;
1) Because of the large time constant of the two-phase servomotor, it can be used as the phase shifter for super-low frequency, and the time constant of the two-phase servomotor can be increased by adding the other moment of inertia.
2) In the compensating circuit using resistors and capacitors, the phase of carrier signal varies according to it, but there is no phase shift of the carrier signal in this compensating device.
3) If we use large output two-phase rate generator, we can pick up the large power signal out of it, without the amplifier.View full abstractDownload PDF (862K) -
Kenzi KAMIYA1968 Volume 4 Issue 4 Pages 357-365
Published: December 30, 1968
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe learning control synthesis is discussed for the noisy linear sampled-data system, the dynamic characteristics of which fluctuates in such a way as follows.
1) The form of the state-transition equation of the system fluctuates within the different forms which are given in advance.
2) The probability taking each one of the given forms is assumed to a random variable with an unknown probability density function.
The learning control problem is reduced to the stochastic control one with estimating the probability distribution of the random variables determining the form of the state-transition equtaion. In this paper, this probability distribution is determined from the joint probability density function of those random variables and the state variables of the system, and this joint probability density function is computed from a prior joint probability density function according to the Bayes rule.
By this learning control process, the system minimizes the conditional expectation of the quadratic form of state and control vectors.View full abstractDownload PDF (1341K) -
Hiroshi KANAI1968 Volume 4 Issue 4 Pages 366-374
Published: December 30, 1968
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSAlthough practical electromagnetic flowmeters are satisfactorily used in industry, many problems still remain unsolved for measuring blood flow with implantable electromagnetic flowmeters. In this paper, four main problems of such flowmeters are discussed as follow:
1) Relation between the flow rate and the electromotive force under various conditions,
2) Drift of the baseline,
3) Inaccuracy of the phasic blood flow pattern measured by an electromagnetic flowmeter which has a non-uniform magnetic field,
a) The conductivity of the wall can not be neglected.
b) The magnetic field of the probe is not uniform.
c) The velocity profile of the fluid is not axially symmetric.
If the magnetic field is not uniform, the sensitivity of the transducer probe varies as a function of the velocity profile of the fluid, even when the average flow velocity remains constant. In this paper, it has been both theoretically and experimentally verified that, when measuring pulsatile flows, the sensitivity actually does vary greatly due to the non-uniform magnetic field. To reduce this error, the design of a suitable exciting coil of the probe is necessary.
The cause of the drift of the baseline is also discussed and a method for reducing it is proposed.The drift of the baseline is greatly influenced by electrostatic coupling between the exciting circuit and the detecting circuit and by the characteristics of the detecting electrodes. In this paper, the characteristics of various kinds of metal electrodes are discussed and it is shown that a platinized platinum electrode is the most suitable for this purpose.
It is also shown that the drift of the baseline is greatly reduced by balancing electrostatic coupling between the exciting and the detecting circuits.View full abstractDownload PDF (2737K) -
Ichiro SUGA1968 Volume 4 Issue 4 Pages 375-381
Published: December 30, 1968
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThere exist some particular classes of integral type performance indices in optimal control, which have been very little discussed. They, however, would be considerably important and helpful to design optimal control systems.
This paper deals with two classes of such performance indices. One is the “uncontrollable performance index” whose value becomes constant regardless of the control function. A sufficient condition of the functional form of its integrand for variour terminal conditions is discussed with some examples.
The other is the “degenerate performance index” whose value becomes minimal for some initial conditions when the control function is always zero during the control interval. A sufficient condition for this case and some examples are also presented.
Furthermore, an illustrative example shows that these two concepts are effective for analyzing the singular problems in optimal control by the use of quite different manner from ordinary methods.View full abstractDownload PDF (937K) -
Takashi YAHAGI1968 Volume 4 Issue 4 Pages 382-388
Published: December 30, 1968
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe w-transform method and the modified w-transform method are developed in this paper. The w-transform can be applied to sampled-data systems which have all samplers followed by zeroorder hold devices. The w-transform is developed utilizing the change of variable, w-n=(e-nsT-e-(n+1)sT)/s, where T is the sampling period and s is the Laplace transform variable.
The w-transform is defined as W[e(t)]=E(w)=∞∑n=0e(nT)w-n.
As the w-transform and the z-transform are the special forms of the Laplace transform, there is no great difference between them. However. the physical meaning of the sampling process using the w-transform method is clearer than that of the z-transform method.
Using the modified w-transform, we can obtain the output response at all times.
An extensive table of Gp(w)and G (w, μ)is presented in the Appendix.View full abstractDownload PDF (673K) -
Masatada YONEMOCHI, Yoshiaki MAEDA1968 Volume 4 Issue 4 Pages 389-396
Published: December 30, 1968
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe edge-tone effect, because of its application in fluitdic oscillators and noise due to splatters, is an interesting problem in fluidics. This effect has been investigated in acoustics by many researchers but the characteristics of jet-edge systems in finite spaces, which are important in fluidics, have not been investigated yet. Especially, the mechanism of edge-tone oscillation has not been made clear.
In this paper, the characteristics of a jet-edge system in a finite space are experimentally investigated and its mechanism of oscillation is investigated both analytically and experimentally. As a result, it is clarified that the characteristics of a jet-edge system in a finite space are affected by the resonance of the finite space and that the mechanism of edge-tone oscillation can be well simulated by a model in which force is fedback from two imaginary pressure sources near the apex of edge to each fluid particle of the jet flow.View full abstractDownload PDF (1937K) -
Tatsuo HIGUCHI, Tadashi KIKUCHI1968 Volume 4 Issue 4 Pages 397-404
Published: December 30, 1968
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSAbout the single core magnetic amplifier recently proposed by Darling, an equivalent circuit transformation and a piece-wise linear analysis are made, and the detailed behavior of the circuit is made clear for the first time.
As a result of the analysis, it is successful to express the amplifier gain in the simple equations. It is also found that the forward voltage drop of the diodes plays an important role in order to increase the amplifier gain, and it is clarified that there exists the optimum value of the diode forward drop, which determins the maximum gain of the circuit.View full abstractDownload PDF (1895K) -
Kanji ETORI1968 Volume 4 Issue 4 Pages 405-411
Published: December 30, 1968
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSAn effect of pulse width, on themeasurement of thermal diffusivity of metals which is not usually taken into account in the conventional formulas, is discussed under the condition of linear flow of heat. In this paper it is reported that the correction to be applied to the method of determination of thermal diffusivity is obtained by solving heat equations having boundary conditions of input heat flux which has a finite pulse width.
The values of thermal diffusivity obtained by the use of the conventional formulas with an assumption of impulse response have some shifts towards values smaller than the correct ones and the shifts can be estimated by the ratio of the pulse width to the lapse of time from the injection of heat pulse to the instant of temperature measurement which are performed at two points.
The above method is shown to be consistent as the result of the measurement on copper.View full abstractDownload PDF (847K) -
Eitiro TAZAKI, Atsunobu ICHIKAWA1968 Volume 4 Issue 4 Pages 412-418
Published: December 30, 1968
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA method is described for obtaining “feasible solutions” in the decentralized optimization of large scale dynamical systems. The “feasible solution” here means the solution which always satisfies the output-input relations among all the interconnected subsystems.
In the method proposed here, the paths of output variables of subsystems are first assumed, the optimization of each subsystem is carried out taking into account the output-input relations as equality constraints and then the condition for the optimal control of the entire system is checked to see whether or not the assumed values of the output variables should be corrected. Therefore, in contrast with the usual decentralized optimal control, the feasible solutions which are realizable in real systems will be obtained after each cycle of the iterative computation of the optimal control path.
The existence theorem of the optimal paths of output variables which make the condition for the optimal control of the subsystems identical with those of the entire system is proved.
An iterative procedure in a function space to find the optimal paths of output variables is proposed and then the stable convergence of the variables into the optimal paths is assured through Lyapunov stability criteria.
A simple example is dealt with to illustrate how the proposed method works.View full abstractDownload PDF (887K) -
[in Japanese]1968 Volume 4 Issue 4 Pages 419
Published: December 30, 1968
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDownload PDF (97K) -
[in Japanese], [in Japanese]1968 Volume 4 Issue 4 Pages 419a
Published: December 30, 1968
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDownload PDF (98K)
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