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Volume 11 (1975)
- Issue 6 Pages 625-
- Issue 5 Pages 501-
- Issue 4 Pages 377-
- Issue 3 Pages 251-
- Issue 2 Pages 125-
- Issue 1 Pages 1-
Volume 11, Issue 5
Displaying 1-18 of 18 articles from this issue
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Simulation of the Fire Spreading in Urban AreasTakafumi FUJITA1975 Volume 11 Issue 5 Pages 501-507
Published: October 30, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSEven for a simple case, the problem of fire spreading is very hard to solve physically.
In this paper, based on Hamada's emirical equation on fire spreading velocity in urban areas, introducing the concept of small “element fires” located on the contour of a fire, the model which can simulate the fire spreading in an actual, unhomogeneous urban area is constructed. The basic derivation of this model is as follows: Deriving the latent velocity of fire spreading in all directions from the element fires on the contour, the real ignition time in a point of combustible area is obtained as the earliest of the fire spreading times calculated by the latent velocities along all paths from the points of fires breaking out.
By this model, the simulation of an actual big fire in the past is carried out, showing the usefulness of the model.View full abstractDownload PDF (1610K) -
A Study of the Decision-Making Process by Playing CardsMasasumi KOKAWA, Moriya ODA, Kahei NAKAMURA1975 Volume 11 Issue 5 Pages 508-514
Published: October 30, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDecision-making in our multi-dimensional society today is very important. The property of “fuzziness” appears usually in a human decision-making process. We have studied to formulate a fuzzy process of human thinking, especially human decision-making. In a series of our studies, the present paper focuses its attention on a fuzzy theoretical one-dimensionalizing method of multi-dimensional quantity. First, in Capter 2, the fuzzy theoretical one-dimensionalizing methods which introduce a fuzzy function with its fuzziness [(i) one-dimensionalizing method by the linear model method and (ii) one-dimensionalizing method by the typical-dimension method] are proposed. Second, in Capter 3, to examine the appropriateness of the proposed methods the estimation problem of an arrangement rule of playing cards (whose applicability as experimental materials was confirmed through our previous studies) is taken up, and the fuzzy theoretical relation between the total inference curve of card arrangement and the inference curve of each dimension (number, suit or color) of card arrangement is studied. At last, in Capter 4, in order to point out the applicability of the one-dimensionalizing method for the ranking problem the character evaluation test is considered, and the fuzzy theoretical ralation between the total evaluation and the evaluation of each dimension (health, fortune, figure or heart) is studied. High appropriateness and wide applicability of the two one-dimensionalizing methods proposed in the paper are shown in the application examples in which the error of estimation and evaluation by the methods is in the allowable domain.View full abstractDownload PDF (964K) -
Masatada YONEMOCHI, Ichiro KIMURA1975 Volume 11 Issue 5 Pages 515-520
Published: October 30, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe noises associated with a fluidic device have been investigated by several authors from different aspects, but the internally-generated noises due to the structural components of a beam deflection amplifier still remain to be studied.
In the present study, the cases of the internally-generated noises were experimentally investigated from the following two points:
1) The noises associated with the design parameters relative to the rectangular flow path (length, aspect ratio, nozzle shape, connecting line), single receiver (width, edge angle at its entrance, position), and load resistance.
2) The source and propagation of the noise caused by the interaction of the control flow with the power flow. This point was investigated by using correlation techniques and spectrum analysis.
The following facts are especially pointed out: The noises in the rectangular flow path are greatly affected by a discontinuous form of the flow path.
The noise source due to the interaction of jets is considered to be in the shear layers formed by the discontinuous velocity of the jet.
The deflection of the power jet is not affected by the velocity fluctuation at the control nozzle and the noises generated at the power and control nozzles propagate along the power flow and the control flow respectively.View full abstractDownload PDF (756K) -
Akira SANO1975 Volume 11 Issue 5 Pages 521-527
Published: October 30, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn actual industrial control processes, quantized control signals are frequently used due to the simplicity of manipulating mechanism. In this paper an analytical method for obtaining a suboptimal feedback control law is presented for linear systems actuated by the quantized discrete control signals.
The technique consists of transforming the state space by an orthonormal matrix, approximating the minimum cost performance with one quadratic hypersurface in the transformed state space, and then deriving the switching hyperplanes seperating the state regions each of which is assigned a suboptimal quantize control. The suboptimal control law is given in the form of the switching hyperplanes obtained by the solution of a nonlinear matrix difference equation for time-discrete systems or of a matrix differential equation for time-continous systems. Advantages of the technique are that the computation of inverse matrices is not required and that only a simple analytical computation is utilized, even in the case when the dimension of the control system increases.
Furthermore, it is proved that the suboptimal control law approaches to the known nonquantized linear optimal control law as the number of quantization becomes large and the quantized level becomes small.View full abstractDownload PDF (855K) -
Teruyuki IZUMI1975 Volume 11 Issue 5 Pages 528-532
Published: October 30, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis study is concerned with the visual information processing of a robot. When the robot recognizes 3-dimensional objects, it has to detet the edges of the objects in the process of feature extraction.
This paper proposes a new method for the edge detection. The apparatus is composed of a slide projector, a TV camera and a computer. On the slide of the slide projector stripes are printed at regular intervals. The stripes are projected on the objects by the projector to be seen by the TV camera. Where the objets are the regularity of stripe intervals is disturbed and caught by the TV camera. The video signal of the TV camera is transmitted to the computer through the buffer memory that has an A-D converter. The edges of the objects are detected according to the information of the cross ratio which is calculated from the stripe intervals by using the computer.
The result of the experiment shows that the above-mentioned method is applicable to the feature extraction of 3-dimensional objects.View full abstractDownload PDF (1607K) -
Akira OHSUMI, Yoshifumi SUNAHARA, Masaaki IMAMURA1975 Volume 11 Issue 5 Pages 533-540
Published: October 30, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA method is presented for estimating unknown parameters in distributed systems for the purpose of detecting pollution sources in environment systems. The system considered is assumed to be modeled by a stochastic partial differential equation whose form is known to be linear and unknown parameters are contained in the exciting terms. The unknown parameters are assumed to be a set of random constants whose a priori probabilities are known.
First, the estimate process of unknown parameters is given by the Bayesian approach in the Markovian framework. The dynamics of the state estimate is also given, which is simultaneously required in the parameter identification scheme. Secondly, the computing procedure is presented, circumventing tedious calculations of the covariance function between the system state and the unknown parameters. Finally, two numerical examples are shown, emphasizing that the dynamics of the observation mechanisms adopted plays an important role in both the state estimation and the parameter identification.View full abstractDownload PDF (1033K) -
Shigenori OHKUBO, Toshiyuki KITAMORI1975 Volume 11 Issue 5 Pages 541-549
Published: October 30, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a construction of the optimal regulator system of a nonlinear controlled process.
Here the process is described in a power series of Kronecker products of the state vector. The nonlinear description is a natural extension of the usual linear matrix notation. All the mathematical manipulation is conducted in the tensor products. The method is straight forward to obtain the unique solution without any arbitrariness in the expression and the manipulation.
The steps towards the solution are as follows:
(1) To build the Hamiltonian, and to get the canonical equation and the maximizing equation of the Hamiltonian with respect to the control (u).
(2) To expand the adjoint vector in a series of Kronecker powers of the state vector, and to substitute it into the canonical equation.
(3) To equate the coefficients of the same Kronecker powers in the both sides of the canonical equation, and to obtain a set of equations which must be fulfilled by the optimal feedback coefficient tensors (Kn, n=1, 2, …).
The equation for K1 coincides with the Riccati equation of the linear optimal regulator problem for the linear part of the controlled object. The stationary Kn(n≥2) can be obtained from well-posed linear matrix equations successively for n=2, 3, ….
By induction, Kn's are proved to be (1, n) type complete symmetric tensors.
When the process is odd nonlinear and the performance function is even nonlinear, the optimal feedback becomes odd nonlinear.
An example with a third-power-nonlinear process, a forth-power-nonlinear performance function, and a third-power optimal feedback, showed much improved responses over the linearized optimal feedkack, especially for the large initial states.View full abstractDownload PDF (964K) -
Ikuro IIMURA, Hiroshi HATANAKA1975 Volume 11 Issue 5 Pages 550-555
Published: October 30, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe frequency characteristics of cavity mounted pressure measuring systems are presented as functions of three dimensionless parameters: the ratio of receiving cavity volume to sensing hole volume, the ratio of hole thickness to hole diameter, and the nondimensional amplitude of signal pressure.
The analysis is based on the orifice dynamics theory developed by J.E. Funk, et al. The experimental work has been conducted for various sizes of sensing-holes and cavities, and for signal amplitudes of 1, 2 and 4 millibars. The derived theoretical frequency response curves, especially, the resonant frequencies and the corresponding maxima (peak values) of the responses have good agreement with the experimental results in wide ranges of the above three parameters.
Therefore, it is concluded that, when a pressure transducer is mounted on a cavity of ordinary size and configuration, the effect of signal (pressure) amplitude on the transducer's frequency characteristics cannot be neglected, even for a pressure amplitude as small as a few millibars.View full abstractDownload PDF (701K) -
Hiromitsu HIKITA, Shoichi KOYAMA, Ryoichi MIURA1975 Volume 11 Issue 5 Pages 556-560
Published: October 30, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe poles of a linear time invariant system can be shifted to the arbitrary positions by state variable feedback if and only if the system is controllable. But in any multi-input system, the feedback gain matrix to realize the desired pole assignment contains redundant elements, because it cannot be uniquely determined.
The redundancy, therefore, can be used for designing multi-input feedback control systems. For example, the zero positions and the steady state characteristics can be improved and/or the low feedback gain matrix can be obtained by determining the redundant elements suitably.
In this paper, we investigate the redundancy of the feedback gain matrix which gives the desired pole assignment to the closed loop system and also present the procedure to obtain the low feedback gain matrix.View full abstractDownload PDF (721K) -
Toshi TAKAMORI, Yuichi MIYAMOTO, Masatada YONEMOCHI1975 Volume 11 Issue 5 Pages 561-566
Published: October 30, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe group delay characteristic of pneumatic transmission lines has been investigated to present a transmission distortion in digital signals and PWM wave signals.
In these signals, interesting information is usually contained in the waveforms rather than in the magnitudes. Therefore, it is important to avoid waveform distortions in pneumatic transmission lines. To estimate the waveform distortions, the group delay transmission characteristic is used for the reasons shown below:
(1) Waveform distortions are estimated in the frequency domain.
(2) Waveform distortions correspond to group delay distortions.
Then, the most desirable transmission line has a flat group delay characteristic.
In this paper, a formula describing a condition of the flat group delay characteristic is theoretically proposed with non-dimensional parameters, and experimentally examinedView full abstractDownload PDF (1084K) -
Haruo OGIWARA1975 Volume 11 Issue 5 Pages 567-572
Published: October 30, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe scattering monochromatic light from a rough surface produces a speckle pattern. The speckle pattern from a moving rough surface is detected by a one-dimensional photo-diode array in order to measure the velocity of the rough surface. The output signal of the detector is a narrow band signal whose center frequency is proportional to the velocity of the surface.
The relation between the geometrical parameters of the optics configulation and the power spectrum of the output signal of the detector is dicussed with the help of Fresnel diffraction theory and spectrum analysis. Especially the relation between the diameter of the illuminated area and the spectral width of the narrow band signal is discussed in detail. A large diameter of the illuminated area is necessary to obtain a narrow band signal. The experimental results demonstrating the soundness of the theory are presented.View full abstractDownload PDF (1284K) -
Synthesis of Digital Feedforward-Feedback Control System for Multivariable System with Inputs DelaysPyong Sik PAK, Yutaka SUZUKI1975 Volume 11 Issue 5 Pages 573-578
Published: October 30, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSMany industrial systems can be represented by a linear multivariable system with time-delays in inputs. In this paper an optimal control problem of such a system is discussed when the reference inputs are polynomial functions of time. The outline of the synthesis is as follows: A new tracking error is defined, where inevitable error due to the system's time delays is not evaluated. The integrated value of the tracking error is also introduced in order to incorporate integral-type controllers into the control system. By imbedding the delayed inputs into the system's state variables, the equation of the controlled system is transformed to a usual state equation without time-delays. A criterion function is a quadratic form of the tracking error, its integrated value and the deviation of controls from their steady state values which are determined so that the system's outputs coincide with the reference inputs. By using this criterion function the synthesis problem is reduced to a standard regulator problem which is easily solved. Advantages of this method are as follows: (1) The optimal control law can be easily derived. (2) The control system has feedback, feedforward and predictive control pass. (3) Offsets due to system parameter variations or disturbances never arise, because the integral-type controllers are incorporated in the control system. (4) Even if the controlled system's time-delays are large, the integral-type controllers do not deteriorate transient characteristics of the control system, because the integral actions are delayed as much as the system's time delays. (5) The parameters of the control system depend only on the parameters of the controlled system and on the weighting matrices of the criterion function, and are independent of the reference inputs.View full abstractDownload PDF (726K) -
Tadashi YAMASHITA1975 Volume 11 Issue 5 Pages 579-585
Published: October 30, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe dynamic stability which is an important problem in a bipedal locomotion system recently attracted various researchers. Dynamic characteristics of a bipedal locomotion system, which consists of a rigid body and two massless legs, are analyzed by a linear mathematical model in this paper. The static frictional force between the supporting foot and the ground has been introduced to analyze the stability of the system. Comparing a solution of the mathematical model and characteristics of the normal human walking, the control strategy in human walking is discussed.
Main results are as follows.
(1) The stability property of the system was studied according to the state of motion, that is, the combination of the position and the velocity of the body relative to the supporting foot: the stable regions were found for some control strategies; the unstable region was classified into subgroups according to the necessary number of switchings of the supporting leg to get into the stable region.
(2) The switching of the supporting leg was shown to be a useful means to stabilize the system. A switching instant and a step length must be selected according to the state of motion.
(3) The control strategy keeping the body in upright posture was studied in detail. The steady locomotion by this strategy exhibited patterns similar to the normal human walking with regard to the body motions and the floor reactions in the sagittal and lateral directions.View full abstractDownload PDF (1011K) -
Akira OHTE1975 Volume 11 Issue 5 Pages 586-591
Published: October 30, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn order to satisfy the needs of large scale instrumentation for current industrial processes, an analog controller with capacitance memory circuit is developed.
In this controller, a part of operating circuit works as memory circuit for manual control. So, using a simple switching circuit, the transfer from an automatic operation to a manual operation and vice versa is performed bumpless without a balancing operation.
This memory circuit is also suitable as a pulse/analog converter, and it is simple to modify the controller as an output station of DDC system which possesses the function of a backup controller for computer failure.
Main component parts of this controller are operational amplifiers. A differential level shift circuit is designed to operate this circuit with a single 24V DC common power supply. This improves system reliability through battery backup against power failure.
To realize a stable capacitance memory circuit, a high input impedance operational amplifier is developed. This amplifier has N channel junction FET input stage and the source drain voltage of FET is kept constant regardless of the input voltage. The input bias current of the operational amplifier is less than 1.5pA (at 25°C). With this amplifier, the drift rate of memory circuit is less than 1% in 70 hours.View full abstractDownload PDF (865K) -
Hideo HANAFUSA, Haruhiko ASADA1975 Volume 11 Issue 5 Pages 592-599
Published: October 30, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIt is an important job for an adaptive industrial robot to search the unknown position of an object. We propose the searching method using pneumatic proximity sensors. That is, the robot with the sensors at the tips of his fingers can detect an object continuously without contact and with flexibility for various sizes of objects by scanning sensors in accordance with a certain rule.
In this paper, we discuss the control method to drive the robot hand exactly to the center of an object, in the case of cylindrical objects or round holes whose diameters are unknown. In this case it is required to scan sensors from the center of the hand to radial directions in order to search the position regardless of the diameter of the object. We show this searching principle, and give the theoretical analysis about the limit of positioning error for all of the initial conditions. And we also show the experimental results of position searching to verify the theoretical limit, and consider the function of this method.View full abstractDownload PDF (1727K) -
Radial Heat Conduction in WallsIsao TODO1975 Volume 11 Issue 5 Pages 600-606
Published: October 30, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe transfer functions of heat exchangers to changes in flow rate, have been derived in most papers assuming that the wall has an infinite thermal conductivity in the radial direction. However, poor heat conductors such as glass and stainless steel, are sometimes used as shell wall and/or tube wall.
In the present paper, the transfer functions, relating the outlet temperature to changes in flow rate, for parallel-flow and counterflow heat exchangers, are obtained by taking into account the finite values of thermal conductivities of walls in the radial direction. Numerical examples of frequency and step responses are given, and the effects of the finite thermal conductivities on the dynamic response are discussed. The theoretical response derived in this paper is compared with the one computed under the assumption that the radial thermal resistance of the tube wall is included in the film coefficients of heat-transfer. As the result, it is shown that there is, in some cases, a considerable difference between the two responses stated above, for the heat exchangers with relatively thick walls made of bad heat conductors. The experiments are carried out based on the frequency response method. A good agreement between the experimental and theoretical results is shown.View full abstractDownload PDF (810K) -
Hideo TSUKUNE, Teruyuki IZUMI1975 Volume 11 Issue 5 Pages 607-612
Published: October 30, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents the new technique for auto-focusing of a TV camera.
An image blur caused by defocusing produces an easy gradient of video signal. The gradient is measured by crossing frequency of a detecting signal over the video signal. This detecting signal is made by superposing a test signal on a threshold level. Using this technique, an efficient blur detection is fully possible with an appropriate selection of three parameters: the threshold level, the frequency of the test signal and the amplitude of the test signal.
By this method, a blur detector is made, the practical parameters are fixed and the range of application is shown. Then, the blur detector and the servo-controlled focus ring are connected, and an auto-focusing experiment is tried.
The results show that this technique is applicable enough to detect the focus inappropriateness of almost all objects.View full abstractDownload PDF (761K) -
Masami MASUBUCHI, Akira ITOH1975 Volume 11 Issue 5 Pages 613-621
Published: October 30, 1975
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSBasic governing differential equations on the heat transfer processes of plate heat exchangers are derived based on the heat balance. Three flow patterns are shown and each flow pattern contains various flow types according to the combination of the plates with a hole or a blank suitably placed at each corner. With each flow pattern the statics such as the steady state fluid temperature distributions and the temperature effectiveness is analysed and also the dynamics is obtained as frequency responses in the case of four passages. These characteristics are systematically investigated. Further, the experimental dynamic responses of the two typical types among four-passage plate heat exchangers are investigated. First, since the relation between the heat transfer coefficient α of the heat transfer plates and the fluid velocity v can be described as α=Cvn, n and C are obtained experimentally. Second, for each heat exchanger the steady state fluid temperature distributions are measured by thermocouples. Finally the experimental frequency responses are obtained by using sinusoidal change of the inlet temperature in the hot-side fluid and by measuring the outlet temperature in the coldside fluid.
The results show that two plate heat exchangers with the same statics do not always have the same dynamics if the flow types of the two are different and that the dynamics is affected more than the statics by the condition whether the inlet-outlet flow pattern of this heat exchanger is parallel or counter flow. And a favorable agreement between the theoretical results and the experimental ones is obtained.View full abstractDownload PDF (1606K)
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