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Volume 23, Issue 2
Displaying 1-18 of 18 articles from this issue
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Image Processing Instrumentation of Flow Velocity Vector Distribution by Using Correlation TechniqueApplication to Vortices in the Wake of a Circular CylinderIchiro KIMURA, Toshi TAKAMORI, Takashi INOUE1987 Volume 23 Issue 2 Pages 101-107
Published: February 28, 1987
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe measurement of flow velocity vector distribution in two-dimensional flow fields has been progressed by the image processing technique. In this technique, a tracer method has been usually adopted for flow visualization and also the velocity vectors have been calculated from the tracer paths extracted during a constant period. The serious problem of this technique, however, is how to separate the overlapped tracer paths.
In this study, each tracer particle is not tracked, but an image of the tracer particles is grasped as a spatial gray level pattern. To obtain the velocity vectors from the spatial gray level patterns, the following procedure is needed. First, two tracer digital images are detected at a constant time interval. Second, each of the two images is divided into many pixel matrices which include the overlapping ones. Third, the cross-correlations of gray level between the respective pixel matrices of the two images are calculated. Forth, the traveling distance and direction of a group of the tracer particles are determined from the maximum value of the correlation. Finally, the velocity vector distributions are obtained.
This method was applied to the two-dimensional water flow behind a circular cylinder.
As a result, the following facts were specifically confirmed:
1) The velocity vector distribution over the entire flow field was obtained without interpolation.
2) The changes of velocity vectors were clearly observed in the vortex fields.
3) The movement and development of the vortices in the flow direction were clearly observed.View full abstractDownload PDF (1523K) -
Shigenobu YAMAWAKI, Eiichi BAMBA1987 Volume 23 Issue 2 Pages 108-115
Published: February 28, 1987
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a procedure to identify inhomogeneous bilinear systems in the distinguishable state space representations from sequences of input and noise contaminated output measurements. The identification procedure is the following; at first, some distinguishable description models are derived from the zerostate response of the systems, then the zerostate input-output maps in the model are estimated by using the baise compensated least square method. Next, the internal discription model is realized by using the previously estimated maps.
The realization algorithm is based on the singular value decomposition of the reachability and distinguishability matrices. Realized the distinguishable canonical forms, the minimal realization systems are obtained to reduce to unreachable states from these models.
Therefore, the proposed methods do not require the factorization of the generalized Hankel matrices. The presented methods are effective as also shown by some numerical examples.View full abstractDownload PDF (854K) -
Tetsurou NOGUCHI, Shinji HARA, Kimio KANAI, Yoshimasa OCHI1987 Volume 23 Issue 2 Pages 116-122
Published: February 28, 1987
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents the effect which generally ignored initial state errors produce on the transient characteristics of the integral type adaptive law with a fixed gain in the design of an adaptive identification system (AIS) based on the continuous time parametric error model. First, the sufficient condition not to increase the solution norm of the adaptive law when obsever errors are ignored is presented. Secondly, it is shown that boundedness of signals assures that the solution norm does not depart in finite time, even if the sufficient condition is not satisfied. At the end of this paper, effectiveness of the analysis results is demonstrated through digital simulation of a simple example.View full abstractDownload PDF (838K) -
Design of a Time-Optimal Digital Control System with Amplitude Limitation of a Manipulation VariableMichitaka KAMEYAMA, Ritaka NAKAMURA, Xi Yue HUANG, Tatsuo HIGUCHI1987 Volume 23 Issue 2 Pages 123-128
Published: February 28, 1987
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSTime-optimal control of discrete systems with a bounded manipulation variable is a complex nonlinear problem. It is well known that much computation time is required to get the optimal solution for this problem. In particular, real-time control which involves the computation of the optimal solution is almost impossible when a microcomputer is used as a digital controller in the applications such as a mechanical control, because of the limitation of its wordlength, memory capacity and computation speed.
In this paper, time-optimal control system with the combination of feedforward and linear state feedback is proposed to overcome the above problem. In the feedforward control, the prestored optimal sequence of a manipulation variable is applied to a controlled system. The optimal sequence can be computed in a short time based on a proposed method using linear programming. In the feedback control, the effects of disturbances and modeling errors can be reduced, which leads to an exact constant value control with robustness. The stationary stability depends on the linear state feedback with a saturation characteristic. So, the stability condition of the state feedback is derived using Liapunov's stability theorem. As a result, it is made clear that microcomputer-based time-optimal controller can be constructed easily.View full abstractDownload PDF (733K) -
Application to the Design of Optimal Servo SystemsTakao FUJII, Narihito MIZUSHIMA1987 Volume 23 Issue 2 Pages 129-135
Published: February 28, 1987
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSFirst, a new design theory of LQ regulator is developed from the practical viewpoint by applying some results on the inverse problem of LQ regulator. The LQ regulator considered here is, unlike the usual one, designed without specifying a performance cost, but it proves to be such a feedback control that minimizes some cost. This theory is then applied to design an optimal servosystem with the following features suitable for practical use: 1) a time constant of the output response can be taken as our design spec., 2) the design computation requires no Riccati solutions, 3) there is a close structural relationship between the controlled system and the resulting feedback matrix.View full abstractDownload PDF (960K) -
Etsujiro SHIMEMURA, Kenko UCHIDA, Tomohiro KUBO1987 Volume 23 Issue 2 Pages 136-141
Published: February 28, 1987
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, a method to construct a linear state feedback law for systems with time-delay is proposed. This method yields a state feedback law by which all poles of the closed loop system are located in the specified half plane. The feedback gain is given from a solution of an infinite dimensional Riccati equation for an auxiliary system defined for the plant. The closed loop system composed by this method is a linear quadratic regulator for a certain criterion. This means that the closed loop system satisfies the circle condition, and thus it has a good robustness property. Moreover, the closed loop system is assured to have an exponential stability with the assigned degree of stability. The proposed design method is quite efficient because an infinite number of poles of the system with time delay can be placed in the desired region by choosing a small number of design parameter.View full abstractDownload PDF (670K) -
Takayoshi TOTANI, Hiroyuki OGAWA1987 Volume 23 Issue 2 Pages 142-148
Published: February 28, 1987
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA quasi optimal solution for the linear fixedend-point, fixed-time problem can be realized by repeated trial and correction of the compensation input to the state-feedback regulator when the knowledge of the system dynamics is inaccurate. The paper presents a method of modifying the input in order to reduce the terminal error using the one obtained in each trial, and shows the convergence condition of this learning process. It is also shown that a similar treatment can be done for the system output which has the same dimensions as those of a model when the dimensions of the object system are greater than those of the model. Simulation and experimental results are given for the settling control of a bridge-crane model.View full abstractDownload PDF (1206K) -
Masami IWATSUKI, Masayuki KAWAMATA, Tatsuo HIGUCHI1987 Volume 23 Issue 2 Pages 149-154
Published: February 28, 1987
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper proposes performance indeces of robot arms from a new viewpoint of the degrees of controllability and observability. The definitions of the controllability, observability and output-controllability Gramians of linear systems are given to show these degrees, and the physical meanings of these Gramians are explained. Using the products of the eigenvalues of these Gramians, the controllability, observability and output-controllability gains are proposed as the measures of performance evaluation of robot arms. Furthermore, it is shown that manipulability and dynamic manipulability can be obtained as the degrees of observability and output-controllability. As a numerical example, a two link arm is evaluated using the controllability, observability and output-controllability measures.View full abstractDownload PDF (765K) -
Haruhiko ASADA1987 Volume 23 Issue 2 Pages 155-162
Published: February 28, 1987
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSManipulator arms are highly coupled nonlinear systems, which are difficult to control. This paper describes a design theory for reducing the dynamic complexity of the manipulator arms. The kinematic structure and mass distribution of a manipulator arm are designed so that the inertia matrix in the equation of motion becomes diagonal and/or invariant for an arbitrary arm configuration. For the decoupled and invariant inertia matrix, the system can be treated as linear, single-input, single-output systems with constant parameters. Hence the manipulator control is simplified and control performance can be improved.
First, the inertia matrix of a manipulator arm is analyzed in relation to the kinematic structure and link mass parameters. Necessary conditions for the manipulator arm to attain the decoupled and/or configuration-invariant inertia matrix are then obtained. For 2 and 3 b.o.f. arms, possible arm designs for the decoupled and/or invariant inertia are determined.View full abstractDownload PDF (1003K) -
Kajiro WATANABE1987 Volume 23 Issue 2 Pages 163-170
Published: February 28, 1987
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis work pertains to the diagnosis of faults in a physically widely dispersed pipeline system. In particular we treat the problem of leak location in a gas transport pipeline.
We have developed a new acoustic method which (a) requires less effort and uses more economical instrumentation than any of the existing method, (b) does not require significant interruption of the pipeline operation, and (c) can locate leak sites clearly. The basic idea underlying the proposed method is derived from the theory of wind instruments. We utilize the fact that the tone of a giant wind instrument (the pipeline) changes in the event of a leak, and we evaluate this change by estimating the acoustic impulse response in the pipeline from acoustic signals detected at the two terminuses of the pipeline.
In addition to explaining the theoretical development that shows why and how the proposed method can detect and locate a leak in a pipeline, we present some experimental results collected under realistic operating conditions with comparisons with simulation results that validate the detection theory and show the desired measurement condition to locate leak site in a gas transport pipeline via simulation.View full abstractDownload PDF (960K) -
Ichiro KIMURA1987 Volume 23 Issue 2 Pages 171-175
Published: February 28, 1987
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA new IC chip selection system with the use of laser beam has been developed. Compared with conventional systems which use microscopes, ITV's and signal processors for detection, the new system facilitates determination of the exact chip position and identification of a bad mark, beveled edge or surface defect with laser beams.
To detect the exact chip position, Fraunhofer diffraction patterns generated by laser at the scribed edges of chips are utilized. For detection of a bad mark and beveled edge, on the other hand, differences of reflecting power are made use of.
This system consists only of two He-Ne laser tubes and three photo-Darlington sensors, outputs of which are led to stepping motors control circuits that drive the X-Y shift table on a chip bonding machine.
The developed system is of simple construction and low cost; it can detect a bad mark instantaneously in contrast to the usual systems which cost considerably more and are less reliable. The reason for this is that optical magnification of the chip surface image by microscopes brings reduced contrast of the image and TV image scanning and A/D signal conversion requires several hundreds of milliseconds.
The correct detection rate by this system was 99.6% as to marks of 600μm diameter on 1.7mm×1.8mm chips and 99.8% as to marks of 300μm diameter on 1.5mm×1.3mm chips. In either case, about 1, 000 chips were tested.View full abstractDownload PDF (1841K) -
Iwao OKUTANI1987 Volume 23 Issue 2 Pages 176-182
Published: February 28, 1987
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA short-term traffic volume prediction model is proposed in this study. The model employs a multi-dimensional autoregressive type analysis so that not only the time series of traffic volume data on the study link of the road network but also traffic volume data on other links which may feed into the study link can be incorporated in the model. The similarity of the traffic flow pattern from day to day is taken into account in making up the prediction model. That is, the parameter vector h involved in the model to predict the traffic flow at k time intervals ahead of time is assumed smoothly changing with respect to day and identified by making use of kalman filtering theory.
The proposed model is tested and compared against the two existing models, i.e., one utilizing the Box-Jenkins method and another based on spectral analysis, by using data collected from a network in Nagano City. The data are 15-min vehicle counts recorded at intervals of five minutes, the time unit in the models. The test results suggest that the proposed model performs substantially (up to 48% in terms of root mean square error of predictions) better than the existing models except in 5-min prediction. The tests also indicate a robustness in model performance as the prediction horizon increases, thus suggesting desirable behavior for longer term prediction.View full abstractDownload PDF (852K) -
Takashi MORIYASU, Yoji MASAGO, Koichi INOUE1987 Volume 23 Issue 2 Pages 183-188
Published: February 28, 1987
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWhile several decision support systems (DSS) for quantitative problems with multiple attributes have been developed, approaches to DSS for qualitative problems are insufficient. In this paper, we present an effective evaluation method for DSS to measure decision maker's preference for qualitative attributes. The method provides utility values on a cardinal scale from decision maker's weighted paired comparisons among all of the alternatives. Since decision maker's weighted paired comparisons are usually inconsistent in a sence of cardinal transitivity, hypothetical weighted paired comparisons nearest to his or hers are found so that they satisfy conditions for cardinal transitivity. If his or her weighted paired comparisons are far from cardinal transitivity, the method suggests modification of them to be more satisfiable of cardinal transitivity. We present an applicational system of our method, which is used to support evaluation of some journals of computers.View full abstractDownload PDF (886K) -
Kamekichi SHIBA, Tadashi ICHINOSE, Jin-ichi KITAMURA1987 Volume 23 Issue 2 Pages 189-191
Published: February 28, 1987
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDownload PDF (333K) -
Yasuaki OKUMURA1987 Volume 23 Issue 2 Pages 192-194
Published: February 28, 1987
Released on J-STAGE: March 27, 2009
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Tetsuo FUJIHARA, Susumu HATTORI1987 Volume 23 Issue 2 Pages 195-196
Published: February 28, 1987
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDownload PDF (316K) -
Kazunobu YOSHIDA, Yukio NISHIMURA, Yoh YONEZAWA1987 Volume 23 Issue 2 Pages 197-199
Published: February 28, 1987
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDownload PDF (344K) -
Mitsuaki ISHITOBI, Zenta IWAI, Akira INOUE, Hidekatsu TOKUMARU1987 Volume 23 Issue 2 Pages 200-202
Published: February 28, 1987
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDownload PDF (389K)
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