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Volume 8 (1972)
- Issue 6 Pages 629-
- Issue 5 Pages 513-
- Issue 4 Pages 389-
- Issue 3 Pages 261-
- Issue 2 Pages 125-
- Issue 1 Pages 1-
Volume 8, Issue 2
Displaying 1-17 of 17 articles from this issue
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Sadahiko MORI1972 Volume 8 Issue 2 Pages 125-131
Published: April 30, 1972
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA new device for observing phase-object is introduced. Its optical system is similar to a schlieren system having a small circular disk or a thin straight wire as a spatial filter instead of a knife edge. A monochromatic point source of coherent and highly bright light is required and a relatively large aperture (blank space or “margin”) which is uniform in refractive index is needed around the object.
A portion of the light beam which is transmitted through and refracted by the phase-object reaches the image plane keeping away from and therefore without being affected by the spatial filter. However, the other portion which passes through the “margin” is partially shaded by the spatial (high-pass) filter. Then, the image of the “margin” is distorted and some components fall on the image of the object and interference fringes appear. When the reference light function D defined in this paper has an absolute value of about unity, and when D remains approximately constant, the fringes have high contrast and coincide with the phase-contours.
As an example, calculations and experiments were carried out in case of a circular phaseobject placed at the center of a circularr field. The calculations predicted that the above conditions could be realized in certain cases and some experiments actually presented clear fringes coincident with the phase-contours.View full abstractDownload PDF (2752K) -
Hiroshi YAMADA1972 Volume 8 Issue 2 Pages 132-140
Published: April 30, 1972
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA conventional hysteresis motor has a small ratio of the output power to the motor volume as compared with conventional induction motors, because the hysteresis material has a small hysteresis loop.
The author has proposed a new rotor structure in which anisotropic magnetic material Alnico 5 is utilized, which has a large hysteresis loop. The proposed hysteresis motor has a large ratio of the output power to the motor volume and a large starting torque as compared with conventional hysteresis motors.
This paper presents the principle, the structure, the voltage characteristics and the equivalent circuit of the proposed motor. The comparison of the theoretical and experimental values of the slip-torque characteristics is also given.View full abstractDownload PDF (1215K) -
Case of Considering the Friction Varied with Angular PositionRyoichi TAKANASHI, Masayuki HATTORI, Tsunetomo ANNO1972 Volume 8 Issue 2 Pages 141-146
Published: April 30, 1972
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn general, the movement of DC servomotor in the range of lower speed is affected remarkably by the friction varied with angular position. By considering such friction, therefore, a new method of analog simulation, which is to simulate more exactly characteristics of the DC servomotor in the lower speed, may be obtained.
In this paper, on the basis of the above consideration, a method of analog simulation for DC servomotor in which the friction torque is dealt with as the sum of the angular velocity component and the angular position component is described.
Furthermore a comparison of the results of measurement and simulation for a servomotor is made. The various characteristics obtained from the measurement and the simulation give close agreement. The cause of the small difference between the results of the measurement and the simulation is briefly discussed.View full abstractDownload PDF (702K) -
Yasuo TACHIBANA1972 Volume 8 Issue 2 Pages 147-154
Published: April 30, 1972
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA super critical boiler is necessarily of an once-through type. Generally this type is able to respond swiftly to load changes, and has a small heat capacity. Therefore the boiler and the turbine should be operated in coordination. Especially in the start-up period, the computer control system may be needed, and for the rise-up control of the temperature and pressure a DDC (Direct digital control) system would be preferable.
In this paper, a rise-up DDC algorithm of the water wall outlet fluid temperature is proposed and the control performance is checked by the use of a digital simulator of combined circulation boiler (1950ton/hour).
A remarkable characteristic of this control algorithm is that it contains the identification of the boiler dynamics and by the results of the estimation the control parameters can be automatically adjusted. Hence we would be able to leave out a prior setting of such parameters which is usually done by the use of the simulator or the real plant.View full abstractDownload PDF (865K) -
Tsutomu WADA, Akira SHIMIZU1972 Volume 8 Issue 2 Pages 155-163
Published: April 30, 1972
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIt has been suggested that the switching of an attaching jet in a wall-attachment fluidic device is directly dependent on the jet deflection. Nevertheless, it seems that the deflection is not sufficiently investigated. In the existing analyses, the parameters, which are obtained experimentally and affected by the geometry of the device, are used. It is desirable that this class of parameter has a well defined physical meaning and is not affected by the geometry.
In this report, the free jet deflection, which is the most basic problem of the jet deflection, is examined experimentally and theoretically. The following matters are confirmed. The main jet momentum at the exit decreases in comparison with the jet without control flow, owing to the pressure rise in the interaction region. On the other hand, the momentum increases due to control flow at downstream. And the so-called discharge coefficient at the flow passage, formed by the main jet and the control nozzle edge, is equal to unity for a small control nozzle setback, while the coefficient is not equal to unity for a large setback, but is much affected by the geometry.
According to the above results, two mathematical models are suggested for the small and large control nozzle setbacks, respectively. For the small setback, the discharge coefficient which is equal to unity, is used. For the large setback, the recovery factor is introduced, which describes the degree of converting the pressure in the interaction region into the momentum at downstream, because the discharge coefficient is very dependent on the geometry.
The results predicted by these models are satisfactory. And the used recovery factor is little affected by the setback.
However, the applicability of the suggested models may be geometrically limited, due to the assumption of uniform, pressure distribution in the interaction region.View full abstractDownload PDF (1093K) -
Masafumi TODORIKI, Hideaki KONYA, Takashi KIKUCHI, Shinobu YASUKAWA, T ...1972 Volume 8 Issue 2 Pages 164-171
Published: April 30, 1972
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSOne of the most significant problems in automatic ticket examination is to check the validity of the route written on a ticket. This problem is due to the service regulation that a passenger with a season ticket can get on or off at any station en route as many times as he likes.
The problem can be divided into three subproblems; (1) coding the railways network, (2) describing the route onto the ticket and (3) checking the validity of it. The item (1) and (2) are concerned with representing the route on the ticket with as little amount of information as possible, and the item (3) is concerned with realizing the judgement function of an apparatus as simply and as inexpensively as possible.
We propose a method to examine the validity of the ticket by describing the route with line-sequence codes. Two kinds of tickets are treated with one mechanism. One is a season ticket and the other is an ordinary ticket for short distance passengers.
Microprogramming technique is employed for the checking circuit of the apparatus. With the same algorithm, an automatic fare adjustment is possible.
The distinctive features of the proposed method are
(1) to cover the nationwide network,
(2) to handle two kinds of tickets with one mechanism both in automatic ticket examination and in automatic fare adjustment,
(3) to cope easily with alteration and
(4) to be able to utilize the same machine at different stations.View full abstractDownload PDF (1066K) -
Tadashi YAMASHITA, Hiroshi YAMADA, Hikotaro ITANI1972 Volume 8 Issue 2 Pages 172-177
Published: April 30, 1972
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper deals with a control method for a kind of stable biped walking. Here studied is the dynamic characteristics of Compass Walk Model, which is adopted by J. Saunders et al. as the simplest model representing the basic characteristics of a human gait. This model consists of a body lumped mass and two massless legs which can rotate only in the sagittal plane.
The motion equation of this model in the sagittal plane is analyzed from the viewpoint of the stability of motion.
Main results are as follows.
(1) According to the ratio of the weight supported by two legs, the dynamic characteristics of this system can be classified into three basic patterns, that is, the stable, the unstable, and the constant-velocity motions.
(2) A variety of stable walking patterns can be realized by reasonable combinations of the basic patterns.
(3) Taking into consideration the acceleration pattern of human body in normal walking, a proper combination of the basic patterns is derived. Its behavior is shown in time domain and phase plane.View full abstractDownload PDF (662K) -
Tomiji HISAMURA, Eiichi INAGAKI1972 Volume 8 Issue 2 Pages 178-184
Published: April 30, 1972
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper investigates an optimal pulse-width-modulated (PWM) control of distributed parameter systems by the extension of Kirk's method. The PWM control is assumed to operate on a boundary of a state domain. Using a variational approach, necessary conditions for optimality are obtained.
A solution which satisfies these conditions can be obtained by the gradient method and a numerical example is shown to illustrate the procedure to obtain the solution.
The merit of this approach lies in its applicability to a comparatively wide range of plant dynamics and types of performance indices.View full abstractDownload PDF (727K) -
Joo Shik HA, Katsuhisa FURUTA1972 Volume 8 Issue 2 Pages 185-193
Published: April 30, 1972
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe identification can be considered as a problem to find the optimal model in a set of models chosen a priori. As a criterion function, (1) response error criterion function, (2) equation error criterion function have been usually used. It has been known that only the response error criterion is applicable when the information about the dynamical structure of the system to be identified is not available. But this criterion function is not much desirable in case when only limited number of observed data of input and output, contaminated by noises, are provided.
In the paper, the improved version of the response error criterion is proposed; i.e., the sum of the following three terms, (1) weighted square error of the initial state, (2) sum of the weighted square error between the input to the model and the observed input, (3) sum of the weighted square error between the output of the model and the observed output.
Minimization procedure with the proposed criterion function is achieved by two steps. First, determination of the optimal initial state and input to the model, which minimize the criterion function for a given model. This first step is known as the optimal tracking problem. Second, minimization of the criterion function with respect to the parameters of the model. This second step is a static optimization problem. The computational algorithm for a linear discrete system is presented.
The criterion function is also explained from the statistical viewpoint and found to be equivalent to the likelihood function in parameter estimation when the structure of the system is the same as that of the model.
The computational examples are given to illustrate the proposed identification method.View full abstractDownload PDF (1012K) -
Nobuhide SUDA, Yoshio IWAHASHI1972 Volume 8 Issue 2 Pages 194-203
Published: April 30, 1972
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe optimal continuous-time filtering problem for the case of linear dynamics, linear measurements, and Gaussian white disturbances and colored measurement noises generated by a limited class of shaping filters excited by white noise input has been solved. However, the colored noise cannot be assumed to take an arbitrary form, in order that the problem become solvable. In a scalar measurement, for example, the noise with exponential type autocorrelation function is acceptable but the noise with exponential-cosine type autocorrelation function, which is also important, is not acceptable. Therefore, it merits a further study to determine the optimal estimator for a colored noise generated by a more general class of shaping filters.
As is often done to solve such a problem, an augmented system is constructed combining the process and the shaping filter. Formulating the problem in this approach, it is known that the original problem is included in the optimal filtering problem for the case of Gaussian white disturbance and the measurements not corrupted by noise.
In this paper, it is shown that this problem is essentially solved by finding a set of bases of the greatest observability subspace with unknown inputs. First, the systematic algorithm is developed to find the bases and the form to which the standard Kalman filter is applied formally, and obtain the formal estimator. And then, it is proved that this estimator is in fact the optimal estimator.View full abstractDownload PDF (1137K) -
Mikio KOBAYASHI, Yasujiro OSHIMA1972 Volume 8 Issue 2 Pages 204-210
Published: April 30, 1972
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper the optimal control problems with constraints in which the state and control variables are allowed to range in Banach spaces are studied by means of a penalty function approach. The constraints treated herein are described by equalities and inequalities which are defined in Banach spaces.
At first, the existence of the optimal and approximate solutions and the convergence of a series of the approximate solutions to the optimal one are discussed in the problems in general Banach space.
Next, the problems in Lp or Euclidean space are treated and the necessary and sufficient conditions for the existence of the optimal solution are derived. These conditions are analogous to those in the Kuhn-Tucher's theorem generalized in the infinite dimensional space.
The results obtained are thought to be applicable extensively to the optimal control problems for the distributed-parameter, lumped-parameter and discrete time systems in which the state and control variables are constrained.View full abstractDownload PDF (882K) -
Kageo AKIZUKI, Tetsushi SASAGAWA1972 Volume 8 Issue 2 Pages 211-217
Published: April 30, 1972
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn recent years there has been a great deal of activity in the study of estimation theory. It is the work of Kalman and Bucy that laid the foundation of this development. In Kalman-Bucy method, it is assumed that the sample paths of the message process and the observed process are continuous in t. Namely, it is supposed that the signal and the observation are generated by Ito's equations, more intuitively, the dynamical system and the observation system are corrupted by white noise. But in this paper, we assume that these systems are disturbed by constantly operating noise continuous in t and disturbances which cause random shocks or jumps in random time.
The object of this paper is to show that it is possible to apply the theory of generalized stochastic differential equations to studying dynamical systems corrupted by additive noise of which sample paths are not continuous in t but continuous in probability.
Also, it is very interesting to study qualitative properties of solutions of generalized stochastic differential equations. In fact, some efforts have been devoted to the discussion of the stability properties of the solution process and to the study of first exit times or, equivalently, to the problem of obtaining useful upper bounds to the probability that the state of the process will leave some given set at least once by a given time.
These investigations are closely related to the problem of stochastic controllability. However, this problem is fairly difficult and scarcely any result has ever been obtained. Therefore, the discussion in this paper is restricted to study only the optimal filtering problem based on Kalman-Bucy's theory. Consequently, this problem is reduced to solve the nonlinear differential equation governing the covariance matrix of the errors of the best linear estimate, called the matrix Aiccati equation and we try to integrate this fundamental equation approximately based on perturbation theory.View full abstractDownload PDF (684K) -
Michio SUGENO1972 Volume 8 Issue 2 Pages 218-226
Published: April 30, 1972
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSLately, the way to express systems consisting of objects with no sharp boundaries and more generally the method to measure such objects have attracted attention of the people in the field of systems engineering. The concept of fuzzy sets defined by Zadeh gives us an important clue for an approach to a study of the above mentioned systems and objects. This paper is concerned with the idea of fuzzy meassure and fuzzy integral and attempts to represent fuzzy systems.
At first, the definition of fuzzy measure is given which has only monotonicity left after removing additivity from the characteristics of measure. Next, the fuzzy integral is proposed by using fuzzy measure. The fuzzy integral is an extention of the Lebesgue integral in a certain sense.
The characteristics, the measurability of functions in a fuzzy measure space and especially the difference between the Lebesque integral and the fuzzy integral are clarified.
Furthermore, a theorem on fuzzy integral in a product space is proved corresponding to Fubini's theorem in the theory of Lebesgue integral.
Finally, this paper discusses, as an example, an application of the fuzzy integral to the problems of board games and suggests possibilities for further applications.View full abstractDownload PDF (1280K) -
Minoru HAYASE1972 Volume 8 Issue 2 Pages 227-235
Published: April 30, 1972
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSSome new relations between the weighting coefficients of performance index and the feedback coefficients of the constructed system, in the standard form of single-input linear constant optimal control problems, are described. The standard form means that the plant is expressed in the phase-variable canonical form and the weighting matrix of the performance index is diagonal. The results are as follows:
1) A technique to transform the general single-input problems into the standard form is presented. In the standard form the problem of solving the algebraic matrix Riccati equation becomes the problem of solving only an n th-order algebraic equation.
2) The fact that, in the standard form, the feedback coefficients of the constructed system are always nonnegative is shown.
3) And the fact that the feedback coefficients of the constructed system are monotone increasing functions of the weighting coefficients is proved.View full abstractDownload PDF (1008K) -
Hajime MAEDA1972 Volume 8 Issue 2 Pages 236-241
Published: April 30, 1972
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper the local stability of relay feedback systems is considered. Concerning the local stability problem, the Tsypkin's conjecture is well known. Namely, if the linearized system is asymptotically stable for large gain including infinity, the original relay feedback system is locally asymptotically stable. The intuitive reasoning for the conjecture is that the saturating nonlinearity that is linear at the origin should approach the relay nonlinearity as the magnitude of the linear gain goes to infinity. The conjecture is verified to be correct by D.V. Anosov in the finite-dimensional cases.
The paper considers the Volterra integral equation and shows that the Typkin's conjecture is also valid under suitable conditions concerning the integral kernel. The results obtained here guarantee that the linearization for stability is applicable for the relay feedback systems containing the distributed parameter systems.View full abstractDownload PDF (664K) -
Minoru HIROTA1972 Volume 8 Issue 2 Pages 242-250
Published: April 30, 1972
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe course of a ship responding to a control (steering order) is represented by a linear differential equation of 3rd order, where the rudder angle is a state variable and constrained in a region. The theme of this report is the time optimal control for the alteration of the course of a ship.
The author introduces Successively Heightening Order Method to find a momentary control, which is the same as that given by the switching surfaces. The method utilizes the control law of 2nd order system with a state variable constraint. The control function of 2nd order system is applied to 3rd order mathematical model to estimate X1E=0, X2E=0, X3E≠0. Then, the control of the moment is given by -sgn (X3E).
The usefulness of the method is illustrated with the trajectories for some initial conditions, plotted by a digital computer.View full abstractDownload PDF (1161K) -
Tomokazu ARAI, Bunjiro ICHIJO1972 Volume 8 Issue 2 Pages 251-257
Published: April 30, 1972
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a circuit system functioning as a capacitance and resistance meter suitable for very-high-loss materials with a wide range of application in various fields of scientific research and industrial operation.
The system for the capacitance meter has two measuring arms; thus, it requires a pair of specimens. An apparent positive reactance variation caused by the low resistance of the specimen placed in one arm is cancelled by the apparent negative reactance variation in the other arm. Therefore, the error due to a large shunt conductance is eliminated from the capacitance measurement.
The system for the resistance meter is a resonance circuit having a very-high Q coil and a differential condenser with a series resistor which acts variable resistance at radio frequencies. The resistance variation caused by inserting the resistance of the specimen into the capacitance measuring circuit is detected as a change in the output of the amplifier circuit. This value is measured by the diferential condenser and the series resistor.
The minimum equivalent parallel resistance of the specimen to be measured reaches as low as 50Ω and the measuring range of the capacitance is about 0.1∼1200pF at 2MHz.
As an application of this circuit system, the dielectric property of wet paper, textile fibers and wood is measured. From the result of the measurement, it becomes clear that the capacitance of woods is proportioned to the moisture content in a region of free water. And the capacitance deviation due to the moisture content is proportioned to the apparent density of wet wood, but not affected by the kind of wood.View full abstractDownload PDF (923K)
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