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Volume 11, Issue 1
Displaying 1-21 of 21 articles from this issue
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Characteristics of Transmission Circuits Composed of Unit Lengths of Parallel Capillaries and VolumesToshi TAKAMORI, Masatada YONEMOCHI1975 Volume 11 Issue 1 Pages 1-6
Published: February 28, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents the power transmission characteristics of fluidic circuits composed of unit lengths of parallel capillaries and volumes, for the purpose of synthesizing a fluidic lowpass transmission network having a good attenuation band characteristic.
In this study, two fluidic circuits having a good attenuation band characteristic are produced by means of a mutually cascaded coupling of a unit length of parallel capillaries and a volume: the cut-off frequency is 150Hz. The characteristic curves at the attenuation band rise at a rate of 40dB/dec in the case of a circuit composed of one unit length of parallel capillaries and two volumes, and 60dB/dec in the case of a circuit composed of two unit lengths of parallel capillaries and three volumes. The circuit becomes symmetrical when the internal impedance of signal source RS and the load impedance RL are equal, and unsymmetrical when RS≠RL. The experimental results for these fluidic circuits agree well with predictions from a lumped-parameter theory, even if Ω_??_40.View full abstractDownload PDF (842K) -
Shintaro ISHIJIMA, Etsujiro SHIMEMURA1975 Volume 11 Issue 1 Pages 7-12
Published: February 28, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIt is well known that the controllability subspace of a linear time invariant system(A, B) is invariant with respect to the operator A. The A-invariance concept plays a central role in the analysis of structural properties of linear time invariant systems. The present article is motivated by a desire to extend this concept to a broader class of significant systems, namely, time varying linear systems. For this purpose a new concept of the effectable subspace is introduced. Using this concept for a class of linear time varying systems, it is proved that a system (A(t), B(t)) can be transformed to the system (A(t), B(t)) by a Liapounov type coordinate transformation so that the controllability subspace over a time interval [t0, t] is invariant with respect to the operator A(t). Based on this fact, the geometric formulation of the controllability subspace is derived.View full abstractDownload PDF (774K) -
Mareo SADAKATA1975 Volume 11 Issue 1 Pages 13-19
Published: February 28, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSSince 1963 traffic information centers have been established in Japan to indicate the degree of congestion.
This congestion information is given by traffic policemen who observe with their eyes the queue length of vehicles at a signalized intersection and convert the length into one of the 5 rankings of degree of congestion. For the purpose of improving the accuracy and saving manpower, demand for automating the measurement has been increasing.
This paper describes the measuring procedure employed in the fully automated traffic information centers, in which the congestion degree is calculated by automatically checking the above-mentioned queue length with vehicle detectors.
In this method, queues can be measured by installing one or two vehicle detectors on the incoming path of an intersection and by reading out the time of occupancy by the detectors.
Since several typical values of the time of occupancy can be obtained depending on the relative distance between the position of the vehicle detector installed several hundred meters upstream from the stop line and the position of the end of the queue, a waiting queue-time of occupancy curve can be obtained.
By using this model we actually measured the congestion degrees, which were classified into four rankings, at several hundred intersections.
Within the range of zero to 1000m of queue length, the results obtained for the measured samples were 89% correct when a single vehicle detector was installed on one incoming path. When two vehicle detectors were installed on one incoming path. 96% of the measured samples were correct.
Since the measuring error is affected by bus stops, road engineering work, etc., the accuracy of measurement is expected to be further improved by minutely examining the installation sites of the vehicle detectors.View full abstractDownload PDF (892K) -
1975 Volume 11 Issue 1 Pages 19
Published: 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDownload PDF (96K) -
Steering and Controlling Method of a Snake-like VehicleYoji UMETANI, Shigeo HIROSE1975 Volume 11 Issue 1 Pages 20-24
Published: February 28, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDesigning, steering and controlling methods for a snake-like vehicle are presented with the experimental results using a model vehicle produced by the authors. Basic knowledge for the methods is obtained from biomechanical research on the snake, and the model vehicle behaves well in accordance with the theory of the methods. A steering system which is not complicated for manual operation is proposed, and the practical cascade control system for the movement in designated shape, speed and direction is synthesized. The model vehicle has twenty segments linked linearly together and is about two meters long. Applicability and technical considerations for further development in the future are discussed.View full abstractDownload PDF (1479K) -
Shohei NIWA, Minoru HAYASE, Ichiro SUGIURA1975 Volume 11 Issue 1 Pages 25-31
Published: February 28, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe stability of linear time invariant systems with state dependent noise is considered by McLane and Kleinman, and a stabilizability condition is given by Wonham.
In this paper, exponential asymptotic stability with probability 1 and mean square stability of a linear time-varying system with Gaussian noise which is linearly dependent on the state variables are considered.
It is shown that the mean square stability implies the exponential asymptotic stability with probability 1 and that it also implies the stability of the system without noise.
As a result, a sufficient condition of mean square stability is given. Using this result a sufficient condition is given for the stabilizability by a state feedback of a linear time-varying control system with state and control dependent noise.View full abstractDownload PDF (829K) -
Michio SUGENO1975 Volume 11 Issue 1 Pages 32-37
Published: February 28, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSSince the concepts of fuzzy measures and fuzzy integrals were proposed, there have been reported several examples of applications which are concerned with subjective evaluation problems of fuzzy objects. This paper defines conditional fuzzy measures and gives the foundation for developing the theory of fuzzy measures.
First, the inverse operation of fuzzy integrals is defined corresponding to the differentiation of set functions. A theorem which is similar to Radon-Nikodym's theorem in the theory of Lebesgue integrals is proved by using this operation. This theorem clarifies that a monotone set function can be expressed by a fuzzy integral under suitable conditions. Here, fuzzy integrals find a new significance of their existence.
Next, by using this theorem, the existence of conditional fuzzy measures is proved. The concept of conditional fuzzy measures corresponding to conditional probabilities is expected to give the theory of fuzzy measures wider regions of applications.
Finally, fuzzy decision-making problems are briefly discussed as an example of applications of conditional fuzzy measures. A theorem is also proved which corresponds to Bayes' theorem in the probability theory. Fuzzy decision-making problems are similar to stochastic decision-making ones and are solved by finding the a posteriori fuzzy measure.View full abstractDownload PDF (815K) -
Case with No Information ExchangeTsuneo YOSHIKAWA, Hiroaki KOBAYASHI1975 Volume 11 Issue 1 Pages 38-44
Published: February 28, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper gives some necessary and sufficient conditions for a linear decentralized control system with no information exchange between its control stations to be observable.
Consider a system with two control stations, x(k+1)=Ax(k)+B1u1(k)+B2u2(k), yi(k)=Cix(k), (i=1, 2, k=0, 1, 2, …), where ui is an ri vector and yi is an mi vector. Let the set Zi(k) of data available to station i at time k be Zi(k)={yi(0), …, yi(k), ui(0), …, ui(k-1)}.
Then a necessary and sufficient condition for the system to be observable by station i is that (i) rank CiBj=rankBj, and (ii) A33 is a nilpotent matrix, (i=1, j=2 or i=2, j=1), when the system and the measurement equations of the i-th station are transformed into a canonical form, where A11: rj×rj, and {A22, C22}; observable pair (in usual sense).
For the case where mi=rj, another necessary and sufficient condition is given, and it is also shown that a necessary condition for the system to be observable by station i is that (i) {A, Ci} is an observable pair (in usual sense), (ii) CiBj is non-singular, and (iii) {A, Bj} is a controllable pair.View full abstractDownload PDF (805K) -
Nobuo WAKABAYASHI1975 Volume 11 Issue 1 Pages 45-50
Published: February 28, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSUsing a control action which consists of constant infusing and exhausting speeds and a neutral zone to maintain liquid level within a give range, a gamma-ray source, a detector and two relays at the upper and lower limits of the counting rate are provided. The optimum condition in this case is discussed and ensured experimentally.
Since a counting rate meter has a time constant and its output is subject to statistical fluctuation, the liquid level may overrun to the opposite limit or move again after settling within the range. Formulas are derived providing the conditions such that these phenomena will not occur more frequently than a given probability. These give the relations between the counting rates of the upper and lower limits, the time constant of the rate meter, a factor of the standard deviation of the counting rate, the infusing and exhausting speeds, and the hysteresis widths of the limiting relays. Since it is derived that the first two of the five terms be smaller and the next two greater, the optimum condition can be decided from the formulas. When the infusing and exhausting speeds are the same and the hysteresis widths are equal, the formulas show the optimum is a case where the ratio of the counting rates at the two limits, which is taken smaller than unity, is small, and where each hysteresis width is equal to 0.34 times the difference between the two counting rates, almost regardless of the value of the ratio.
Similar relations can be also derived in a batch process control composed of a single infusion or exhaust to the desired level.
The above-mentioned deductions were examined in a system constructed with a backscattered gamma-ray type level gauge and a controller for infusion and exhaust of water.Its results almost agreed with those of the deductions when the factor of the standard deviation is substituted for by 2.View full abstractDownload PDF (832K) -
Yoshifumi SUNAHARA, Koji KAMEJIMA1975 Volume 11 Issue 1 Pages 51-56
Published: February 28, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, sufficient conditions for the stochastic controllability of nonlinear distributed parameter systems are established by the stochastic Lyapunov-like functional method.
First, nonlinear distributed parameter systems subjected to random excitations are described by the stochastic evolution equation in L2-space.
Secondly, the stochastic controllability concept is defined in the sense of the L2-norm, and a theorem is proved to give sufficient conditions for stochastic controllability. Since the conditions are stated implicitly in terms of a stochastic Lyapunov-like functional, it is necessary, from the practical point of view, to construct the functional from system parameters. For this purose, a distributed parameter system with an additive control signal and subjected to noise disturbance depending linearly on the system state is considered. Controllability conditions are obtained which contain Kalman's condition as a special case.
The remainder of this paper is devoted to developing comparative discussions of the controllability conditions obtained here with those for linear deterministic distributed parameter systems.View full abstractDownload PDF (787K) -
Fumiya FURUNO1975 Volume 11 Issue 1 Pages 57-62
Published: February 28, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe conventional moving coil meters used for temperature measurements in conjunction with a thermocouple or resistance bulb often suffer from troubles due to their small drive torque and delicate mechanical construction.
The purpose of this paper is to discuss a temperature indicator which is newly developed with the intension of solving such common problems.
The indicator unit is essentially composed of a pair of fixed cross coils and a movable permanent magnet with a pointer and used together with an IC amplifier.
A signal voltage from a suitable temperature sensor is, after amplification, applied to the junction point of the coils, being series-connected and powered with a stable DC source. The amplifier output controls the respective currents through the coils and hence induced magnetic fields. The magnet, located in the center of both coils takes the direction of the resultant field and indicates the input signal.
In order to attain reasonable damping characteristics, a pair of damping coils are placed close to the magnet. The induced voltage, nearly proportional to the angular velocity of the magnet, is applied to the amplifier for negative feedback.
The indication characteristics are theoretically analyzed and compared with the experimental data. The indication difference has been reduced to 0.2% of full scale by means of electronic adjustments and magnetic compensation.
It is possible to obtain a large indicator torque such as 5 to 6mg-cm/deg, about 10 to 30 times larger than by conventional moving coil meters.View full abstractDownload PDF (1337K) -
Takashi MATSUMOTO1975 Volume 11 Issue 1 Pages 63-69
Published: February 28, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA class of evasion problems with linear dynamics is discussed. The problems turn out to be difficult in that the evader must prevent capture on an infinite interval of time in order to accomplish his escape. Two results are obtained and applied to some nontrivial examples.View full abstractDownload PDF (920K) -
Taku NISHIYAMA1975 Volume 11 Issue 1 Pages 70-75
Published: February 28, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSAs is well known, counting scales are widely used for counting many small machine parts. In this case however there is always an error in counting, so it is necessary for us to know the probability of miscount.
The present paper gives the exact definition of this probability and a method to calculate it.
There are three causes of miscount. They are the dispersion of part weight, the dispersion of balance and the error due to round-off. Their effects on miscount will become clear in this paper.
In the remaining part the author deals with the problem of independence of lot weight. If one judges that lot A is in equilibrium with lot B, then the weight of lot A is not independent of that of lot B. The weight distribution of lot A is necessary to calculate the probability of miscount in using a Roberval balance repeatedly. Introducing a function h(x|δ), the author obtains the distribution function.View full abstractDownload PDF (780K) -
Nobuo FUJII1975 Volume 11 Issue 1 Pages 76-82
Published: February 28, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, controllability problems are considered for control systems governed by a system of partial differential equations of parabolic type in one dimensional (half) space.
Controllability for the system on which control is exerted by means of parameters distributed all over the space is considered in some detail. Sufficient conditions for controllability by means of a finite number of parameters are obtained and a few illustrative examples are given. Mathematical methods used to derive the results are elementary.
Similar mathematical methods are applied to the controllability problem of the system on which control is exerted by means of a finite number of parameters in boundary conditions. It is shown that the parabolicity of the equations which govern the system guarantees the controllability, when only the highest order spatial differentiations are contained in the partial differential equations.View full abstractDownload PDF (886K) -
Tsutomu WADA, Akira SHIMIZU, Minoru TAKAGI1975 Volume 11 Issue 1 Pages 83-89
Published: February 28, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe many existing analyses and experiments for reattaching jets have been mainly concerned with fairly simple models. In fact, however, the jet in wall-reattachment fiuidic devices may interact with a splitter and a decoupling vent which are necessary for fulfilling the function of the device.
In this paper, the effects of the vent and the splitter on the reattaching jet behaviour and its switching were experimentally investigated. Introducing “Run-out Flow Intensity” Prun/Ps, defined by the ratio of run-out flow total pressure to supply total pressure, the effects were made phenomenologically clear.
The concluding remarks are as follows:
(1) Though the splitter suppresses the bubble expansion due to control flow, this suppression is greatly weakened by the vent, due to the jump phenomenon of the jet.
(2) The known switching modes can be inclusively explained by introducing “Run-Out Flow Intensity”.
(3) The basic data for designing the device with vent and splitter are shown.View full abstractDownload PDF (1979K) -
Yoshiaki KOMATSUBARA, Kazumichi NISHIOKA, Hiroto SAEKI1975 Volume 11 Issue 1 Pages 90-96
Published: February 28, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, the switching transient of the jet for a bistable wall attachment fluid amplifier is investigated by a quasi-steady state analysis, applying the theory based on turbulent jet entrainment properties.
From the experimental results which were carried out in advance to compose the theoretical model, it was recognized that there was a considerable difference in the pattern of jet switching according to the magnitude of the output resistance.
The theoretical model adopted here could be applied in the case of a comparatively large output resistance and small control to supply momentum ratio.
In work previously done, Lush considered the momentum interaction between the supply and control jets, and Epstein took further the mass interaction into account. The authors also considered the momentum interaction between them, but the mass conservation was treated in the attachment bubble.
The limitation due to deciding the end of the switching transient, appling Epstein's model, was avoided by the Jet Swithing Volume Rate, which was experimentally given under consideration of the Effective Bubble Volume Factor proposed by the authors.
Further, if the jet spread prameter were suitably varied throughout the switching transient, the behaviour could be explained more exactly by this model. The effect of the variation of this spread parameter is also discussed in this paper.View full abstractDownload PDF (1618K) -
With Two Simple LeversTaku NISHIYAMA, Ryuichi MASUO, Chikayoshi MAEDA, Junichiro SHINOZAKI1975 Volume 11 Issue 1 Pages 97-102
Published: February 28, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThere are many papers on scales, but they all assume that the scale is lying on the horizontal plane at rest, and existing scales are all designed on that assumption.
Because of the increasing number of large fishing vessels containing plants for dressing fish, the demand for shipboard scales which can be used on a moving base is increasing.
The authors intended to make a shipboard scale and have found two ways to make it. One is the way in which
(1) one reads the difference of the two angles of deviation of two independent levers which swing in the same way when the base swings.
The other is the way in which
(2) one constructs compound levers which are connected so as to cancel the influence of the motion of the base.
A product based on case (1) will be manufactured shortly. The authors explain the theory of the simple lever which is fixed on a moving base, introduce experimental data, and show the usefulness of the first way in this paper. They will be publishing the details for case (2) following this explanation of case (1).View full abstractDownload PDF (3246K) -
Kunihiko ICHIKAWA1975 Volume 11 Issue 1 Pages 103-107
Published: February 28, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA method for calculating the unknown initial state from observed output data and control input data is shown in this paper. These data are dealt with as a batch and not continuously in this method. The essential point of the method is to calculate the initial state by constructing an optimization problem and then solving it by the steepest descent method. The method can be applied to nonlinear systems. Two examples show that the initial state can be estimated without discernible error by this method. In the case of a linear time-fixed system, the optimization problem can be solved analytically and does not require the steepest descent method.View full abstractDownload PDF (610K) -
Yoshihiro IKEDA, Shiro HATA1975 Volume 11 Issue 1 Pages 108-112
Published: February 28, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper is concerned with 1/2-harmonic self-oscillation of a first-order system involving a thyristor amplifier.
From investigations of an equivalent PWM system, it is shown that the only 1/2-harmonic self-oscillation occures in the instability state.
The method of analysis is based on the equation of the system in the state of the limit cycle. The method is applied to closed-loop systems with two kinds of thyristor amplifier, namely an AC-DC converter and a DC chopper, and rigorous conditions for the 1/2-harmonic self-oscillation are obtained in suitable forms for numerical calculations. The analytical results are verified with the experimental results obtained on voltage stabilizing circuits.View full abstractDownload PDF (710K) -
Yo IKEBE, Katsumasa SUZUKI1975 Volume 11 Issue 1 Pages 113-119
Published: February 28, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSRecently, electro-hydraulic servosystems have come to be applied widely to systems like material testing and vibration testing equipment.
The bandwidth of these systems is required to be broader than 100Hz.
The spool valve servomotor, which plays an important role in the above mentioned systems, is also required high frequency response.
We have often experienced some problems of the servomotor peculiar to the high frequency region, such as self-excited oscillation of the spool valve.
On the other hand, to the authors' knowledge, there have been few published papers covering both theoretical and experimental research on the dynamic characteristics of the servomotor in the frequency region much higher than 100Hz.
The purpose of this present research is to make clear the high frequency characteristics of the servomotor, not only theoretically but also experimentally.
Theoretical results, given in a form of a distributed parameter system, fairly well coincide with the experimental ones.
Numerical calculation of the theoretically given characteristics is so complicated that an approximated frequency transfer function is derived. By the use of this function, the general trend of the frequency characteristics of the servomotor is investigated.
From the results of the theoretical and experimental research, it becomes clear that in order to obtain a servomotor having high frequency response, attention must be paid in designing not only to the dimensions of the conduits but also to the magnitude of the valve and cylinder chambers.View full abstractDownload PDF (883K) -
Ken HIRASE, Hidenori KIMURA1975 Volume 11 Issue 1 Pages 120-121
Published: February 28, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDownload PDF (213K)
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