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Volume 24, Issue 12
Displaying 1-23 of 23 articles from this issue
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Yoshihiko OZAKI, Hidenori YASUDA1988 Volume 24 Issue 12 Pages 1225-1231
Published: December 30, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper describes a study on a drycalibration method for application of an ultrasonic flowmeter to the fields such as nuclear or thermal power plants where high temperature and pressurized fluids are used in coolant or feedwater systems.
For the measurement of the flow quantity using the ultrasonic flowmeter, it is important to obtain a correction coefficient of the rate of line averaged axial velocity to plane averaged axial velocity.
We have developed analytical method to predict the turbulent flow profiles in the cross sections of piping including bends. The method is based on parabolic flow model and k-ε model with wall functions for the near-wall regions.
The axial velocity profiles and the correction coefficients predicted by the analytical method were compared with the experimental results for water and liquid sodium in various L/D conditions.
The both results were shown to be in approximate agreement within about 5% accuracy for the flow profiles and about 2% accuracy for the correction coefficients, though the piping had the 90° bend with a very small redius of curvature. In the case of small L/D conditions, it was also shown that the reverse flow effects could not be disregarded in the predominant direction. However, the accuracy of the dry-calibration by using the analytical method was confirmed to be within about 2% as things were.View full abstractDownload PDF (383K) -
Kajiro WATANABE, Hiroshi SUZUKI, Yasuhiro TAKEBAYASHI, Eiji KAWA1988 Volume 24 Issue 12 Pages 1232-1237
Published: December 30, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe volume of gas in a closed liquid tank can be calculated from measurement of changing pressure of gas in the tank that occurs according as the change in the volume of gas in the tank by applying the ideal gas law. The volume of liquid in the tank is obtained by subtracting the volume of gas from the capacity of tank.
This paper treats the substantial problems which could occur when the above idea is applied to a real flexible automobile fuel tank, i.e., (1) how to compensate deformation of the flexible tank, which occurs according as the change in the volume of gas in the tank, (2) how to design a measurement system effectively implemented for automobile fuel tanks, and (3) what is the desired measuring condition to reduce effects of pressure noise occurring in the fuel tank of a running automobile, and presents a new measurement system that could solve the problems (1) and (2), and shows the desired condition in (3).
A measurement system realized by analog electronics circuits and measurements by the circuit demonstrate the proposed method can be effectively applied to automobile fuel gages.View full abstractDownload PDF (1399K) -
Hiroshi SAITO, Nobuya TAMURA1988 Volume 24 Issue 12 Pages 1238-1245
Published: December 30, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSTo improve reliability of measurements of particle size distribution, performances and characteristics of three measuring methods, scanning electron microscope-image analysis (SEM-IA), electric resistance analysis (ERA) and centrifugal sedimentation analysis (CSA), are compared and discussed. In this study, polystyrene/polyviniltoluene (PS/PVT), monodisperse particles and alumina particles ranging from 0.5 to 5μm in diameter are used.
It is shown that the ERA's data on the particle size distribution agrees with the SEM-IA's within 5% in the average diameter and within 0.05μm in the standard deviation for the PS/PVT monodisperse particles, but the CSA's data significantly differ from those of the others. In the CSA, Stokes' condition for particle sedimentation is distinctly disturbed by a temperature rise due to high speed rotation of sample. A new technique is proposed and confirmed to be effective to reduce the disturbance.
In the measurement of alumina particles, the obtained data are incompatible each other among the three measuring methods, because amorphous particle shape and wide size distribution of alumina particles give inherent and different characteristics for the particle detections in the respective measuring methods.View full abstractDownload PDF (1164K) -
Youshe CHEN, Shinji HARA1988 Volume 24 Issue 12 Pages 1246-1252
Published: December 30, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper is concerned with a robust stabilization problem for plant uncertainty of the first-order lag type. The necessity of the robust stabilizability is investigated using conformal mappings and the Nevanlinna-Pick interpolation theory. A necessary condition is derived for the existence of a controller that stabilizes all SISO linear plants with prescribed bands of the gain and time constant. The sufficiency is also discussed based on the result for the weighted stable factor perturbation. We propose a method of choosing the weighting functions and the band function corresponding to the first-order lag type perturbation.View full abstractDownload PDF (917K) -
Toru FUJINAKA, Kenji SUGIMOTO, Yutaka YAMAMOTO, Tohru KATAYAMA1988 Volume 24 Issue 12 Pages 1253-1259
Published: December 30, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn the design of discrete-time optimal regulators the location of the optimal closed-loop poles is determined by the weighting matrices of the performance index. When the controlled object is given in such a way that certain mode is decomposed from the others, it is possible to specify the weighting matrices so that only the specified mode is altered. This paper aims at clarifying the relationship between the weighting matrices and the optimal poles. Assuming the procedure of moving one real or a complex conjugate pair of poles and then confining the discussion to the corresponding eigenspace, the method gives rise to a systematic characterization of optimality after pole-shifting. To this end, the basic property of the associated symplectic matrix, namely the fact that the optimal poles are given as the eigenvalues of the symplectic matrix, is effectively used. The result is applicable to determining the domain where the closed-loop pole can be optimal. This is an extension to the results of Solheim (1974) and Amin (1984).View full abstractDownload PDF (911K) -
Yoshiaki KAWAMURA1988 Volume 24 Issue 12 Pages 1260-1267
Published: December 30, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, the discrete-time system is studied, and some orthogonality conditions are derived about response signals in optimal control. These conditions are just dual relations of well known orthogonality conditions on the linear least-square estimate. Assume that a control system has an inside driving signal (system noise) and an outside control input signal. The most basic orthogonality for the optimal system is stated as follows: The response for the impulse driving signal is orthogonal to the response for the posterior impulse control signal. This is the dual property of the following orthogonal projection theorem for the linear least-square estimate: The estimate error is orthogonal to prior observation. The above condition for the optimal control is simplified for a deterministic system with no deriving signal as: The initial state response is orthogonal to impulse responses. The duality is an extension of the well known duality written in terms of Riccati equations. Other orthogonality conditions are also clarified for the optimal control such as dual properties of orthogonality related to the innovation process.View full abstractDownload PDF (1020K) -
Tetsuzo TANINO, Naohiko TAKAHASHI1988 Volume 24 Issue 12 Pages 1268-1275
Published: December 30, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSExistence of fixed modes is not desirable for stabilization and pole assignment in linear time-invariant decentralized control sytems. Therefore, it is necessary to eliminate (undesirable) fixed modes by some methods.
In this paper, two methods are proposed for elimination of fixed modes of linear control systems with constrained control structures, typically including decentralized control structures. The methods make most use of the existent controllers and observers.
One method is addition of interconnection gains to the feedback structure. The minimal number of necessary additional interconnection gains and the positions to which they are added are made clear, based on the degrees of the fixed modes and the corresponding minimal effective subsystems.
The other method is addition of new control stations to the original system. The minimal total number of inputs and outputs necessary for elimination of undesirable fixed modes is provided, also based on the degrees of the fixed modes and the minimal effective subsystems. The proof shows how to construct new stations at the same time.View full abstractDownload PDF (959K) -
Chieko ONUMA, Kunio SAITO, Takamasa HORI, Masahito IKEDA1988 Volume 24 Issue 12 Pages 1276-1283
Published: December 30, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSRecently thyristors are employed in railway substations instead of silicon rectifiers. The thyristors as rectifiers of substations would make it possible to control service voltage of power feeding line. Such a system would improve the quality of service power for trains and would reduce installed rating of substations.
This paper evaluates limits to reduce fluctuation of pantograph point voltage by controlling the feeding voltage every moment in an ideal power feeding system in which all substations are thyristor-type and have invertors to accept regenerated power. The control algorithm consists of
(1) distributed feeding voltage control, which compensates for the drop of feeding voltage by estimating related pantograph point voltages of the objective substation, by making use of voltage and current values of the substation and its adjacent substations, and (2) cross current control which prevents cross current generated by service voltage control. This control algorithm was evaluated by computer simulation using an electric circuit model which consists of branches and nodes for the feeding system. The simulation showed that the proposed control algorithm reduces 11-23V of deviation in minimum pantograph point voltage and 10-20V in average pantograph point voltage with the comparison of conventional system. The installed rating of substations reduces 5-20%, on condition that the control of pantograph point voltage is combined the demand control and the current of root mean square control.View full abstractDownload PDF (1205K) -
Shinichi HIRAI, Haruhiko ASADA, Hidekatsu TOKUMARU1988 Volume 24 Issue 12 Pages 1284-1291
Published: December 30, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA new approach to the kinematic analysis of object motion constrained by mechanical contacts is presented. In robotic manipulation, such as grasping and assembly, robots manipulate objects through mechanical contacts with the grasped object and with the environment. We need to understand the kinematic behavior of the object motion under the constraints by the mechanical contacts in order to find appropriate strategies for manipulation tasks.
In this paper, we first show that the constraints by mechanical contacts are generally described by a set of homogeneous linear inequalities. In task planning, it is often necessary for the planner to treat the complex inequalities. Thus, we develop an efficient mathematical tool based on the theory of polyhedral convex cones in order to treat the inequalities in a simple and systematic manner. Furthermore, we develop computation algorithms of the polyhedral convex cones in order to treat the inequalities on a computer. We apply the method to the planning of form-closure grasps, workpiece fixturing and hybrid position/force control. Several examples demonstrate the usefulness of the algorithms.View full abstractDownload PDF (1106K) -
Haruhiko ASADA, Yukio ASARI1988 Volume 24 Issue 12 Pages 1292-1298
Published: December 30, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA new approach to the teaching of skills that human workers have acquired in performing specific tasks is presented. First, a skilled worker shows how to perform a given task, and his motions are measured. Specifically, the force exerted by the worker and the displacement of the tool manipulated by the worker are monitored and stored in a computer. The data are then analyzed in order to find the control law of the human expert. The functional relationship between the force and the displacement is derived from the data by using a curve fitting technique. The identified relationship is then used as a reference model for controlling a manipulator arm to replicate the expert motion. The method is also applied to the impedance control of a simple grinding robot. The impedance with which a human expert holds the grinding tool is identified. Then the identified impedance is transferred to the robot controller so that the system may follow the impedance model, which is a replica of the human expert.View full abstractDownload PDF (930K) -
Akihito SANO, Junji FURUSHO1988 Volume 24 Issue 12 Pages 1299-1305
Published: December 30, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn the study of walking systems, it is very important to find some indexes for analyzing walking and deciding its control strategy, because the degree of freedom of a walking system is very high. In regard to biped locomotion systems, the angular momentum of the whole system can be considered as a good index, since it is a stable quantity, as seen from ‘the law of the conservation of angular momentum.’
Good indexes for quadruped locomotion systems have not been proposed yet. The body speed is an index of quadruped system. However, the body speed is not so good index for representing the state of the whole system since it is changed easily by the sway motion of swing legs, etc. In this paper, the authors defined a stable quantity which is not affected by the sway motion of swing legs or the movement of knee joints of supporting legs. We named this quantity ‘Quasi-Angular-Momentum’. The quasi-angular-momentum is varied only by the gravity effect and input torque at the hip joints of the supporting legs. So, this quantity can represent the state of the quadruped system as a whole. By using the quasi-angular-momentum, two kinds of dynamic walking are analyzed. One is a walking which utilizes the gravity effect skillfully and the other is a walking in which the body speed is kept constant.View full abstractDownload PDF (407K) -
Toshihiko SAKAI, Yuji NARITA, Takao YAMAZAKI1988 Volume 24 Issue 12 Pages 1306-1311
Published: December 30, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA heat resistant robot has been developed to repair cracks of coke ovens. The robot utilization in the high temperature up to 1, 000°C requires the cooling structure design, suitable repair equipment, a three dimensional measurement system, and an appropriate control system. This paper is concerned mainly with the measurement and the control system of the robot.
To begin with, the crack can be identified on the monitor of a TV camera which is installed in the robot arm. A fixed angle triangulation and the point indication on the monitor form three dimensional data of the cracks for the robot controller. During the automatic repair of the crack, the operator can watch and check the trace of the repair by using another TV camera in the arm, and adjust the repair path. The robot has good man-machine interfaces such as the fine adjustment of the path. And the control system has been developed to be an effective cooperation system of the automatic control with the remote control.
Repair tests in the coke ovens have proven the adequate heat resistance. The control accuracy in the high temperature was assured to be within ±3mm.View full abstractDownload PDF (1480K) -
Takehisa ONISAWA1988 Volume 24 Issue 12 Pages 1312-1319
Published: December 30, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a method to represent human reliability in terms of the error possibility which is a fuzzy set on [0, 1]. This method considers not only the error rate but also many factors, e.g., task conditions, stress level, aptitude, etc. These factors affect human performance.
First of all three kinds of experiments on a microcomputer have been performed. The qualitative expression concerned with human reliability is obtained by the analysis of the experimental result. Based on the qualitative expression human reliability is estimated by many factors, i.e., task conditions, stress level and aptitude. Lastly the method to obtain the error possibility by fuzzy reasoning is presented on the assumption that the basic error rate is given.
As an illustrative example the wrong selection from a functionally grouped set of manual controls is considered. It is shown that the error possibility obtained by the present method represents well the experimental result and the human reliability estimated in an accident.View full abstractDownload PDF (1071K) -
Mikio MAEDA, Shuta MURAKAMI, Toshikazu ONOUE1988 Volume 24 Issue 12 Pages 1320-1327
Published: December 30, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper deals with an medical fuzzy expert system for the diagnosis, the test (examination), and the treatment in the anovulation. This system is consisted of the three parts which are the knowledge acquisition and change system, the reasoning engine, and knowledge data base. Each part is constructed of some frames. Knowledge rules for the diagnosis and the selection of the test and the treatment are represented by the fuzzy production rules. And those are set in the frames of disease, test, and treatment.
In this system, the possible diseases, the tests for the diagnosis, and the treatments of the disease are obtained by the approximate reasoning. But the test and the treatment are finally selected by evaluating the factors such as the cost, the risk, the amount of information, and effect before those are put in practice.
As an application of this system, 43 examples of anovulatory women are simulated based on those clinical records.View full abstractDownload PDF (1177K) -
Takashi HIRAI, Tohru KATAYAMA1988 Volume 24 Issue 12 Pages 1328-1330
Published: December 30, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper develops an algorithm of identifying the parameters of the semicausal image model. A large vector AR model is decomposed into nearly uncorrelated scalar subsystems by the DST, to which the LS method is applied to identify the unknown parameters. Simulation results are also shown.View full abstractDownload PDF (679K) -
Yutaka YAMAMOTO1988 Volume 24 Issue 12 Pages 1331-1333
Published: December 30, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis short note gives a rigorous condition and proof for convergence of learning control of linear time-invariant systems, especially for the case of not using the derivative of the error signal. The proof also clarifies the existing confusion in the literature.View full abstractDownload PDF (396K) -
Shinji SHINNAKA1988 Volume 24 Issue 12 Pages 1334-1336
Published: December 30, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSFirstly, it is pointed out that exponential convergence for a certain adaptive algorithm of constant-trace-gain type can be easily proved. Secondly, but as main contribution of this short paper, the general conditions, a tight upper bound and a simple proof of exponential convergence for a generalized recursive least squares algorithm are given.View full abstractDownload PDF (360K) -
Noboru SEBE, Young-Taek HYUN, Seiichi SHIN, Toshiyuki KITAMORI1988 Volume 24 Issue 12 Pages 1337-1339
Published: December 30, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper proposes a double-compensator configuration with passive redundancy. In the proposed configuration, each compensator observes the output of the other compensator. The necessary and sufficient conditions for the stabilization of this configuration are given.View full abstractDownload PDF (338K) -
Toshitaka FUJIWARA1988 Volume 24 Issue 12 Pages 1340-1342
Published: December 30, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIt is important to decide the arrangement of PID controller with multivariable control system.
Therefore, this paper describes the selection method of the effective combination between the controlled variables and manipulating variables.View full abstractDownload PDF (387K) -
Tsuneo YOSHIKAWA, Yasuyoshi YOKOKOHJI1988 Volume 24 Issue 12 Pages 1343-1345
Published: December 30, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSFour types of link coordinate frame assignment for serial link manipulators are discussed. It is shown that the computational amount of inverse dynamics can be reduced by only changing the assignment. Optimal link coordinate frame assignment is proposed.View full abstractDownload PDF (401K) -
Shigeru FUTAMI1988 Volume 24 Issue 12 Pages 1346-1348
Published: December 30, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSNew control algorithms that make possible a minute positioning and a stick-slip-free feed control are proposed for a servomechanism in the presence of nonlinear friction.View full abstractDownload PDF (311K) -
Michio NAKANO1988 Volume 24 Issue 12 Pages 1349-1351
Published: December 30, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSMany robust-systems have been proposed. One of them is “load insensitive servo system” by Y. Ikebe and others. This system has good characteristics but there are some problems in appling this method to a real plant. In this paper, I discuss about these points and show the new system structure to realize robustness.View full abstractDownload PDF (295K) -
Masao IKEDA, Dragoslav D. SILJAK1988 Volume 24 Issue 12 Pages 1352-1353
Published: December 30, 1988
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSImitating the idea of state feedback in control theory, a new equivalent transformation for linear algebraic equations is proposed. A useful application of the transformation is decomposition of a large equation into small equations which are independent of one another.View full abstractDownload PDF (252K)
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