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Volume 20, Issue 1
Displaying 1-14 of 14 articles from this issue
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Toshimitsu NISHIMURA1984 Volume 20 Issue 1 Pages 1-7
Published: January 30, 1984
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA Necessary and sufficient condition for the existence of a steady-state solution of the covariance equation is derived both for the fixed-interval smoother and fixed-point smoother. Such condition is expressed in a concise form employing the detectability and stabilizability of the related system and a unified conclusion is reached for these two smoothers.
Finally a computing algorithm to obtain such steady-state solution is introduced and it is demonstrated that the results of the filtering solution are directly applicable.View full abstractDownload PDF (875K) -
Yuzo YAMANE1984 Volume 20 Issue 1 Pages 8-15
Published: January 30, 1984
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper is concerned with presenting an approach of designing a system observer for a linear multivariable discrete unknown system of an unknown order, based on a view of underlying stagnant system. The system observer can construct simultaneously both estimates of state and estimates of parameters of the original unknown system. Several special features are shown below;
(1) Output stagnant system arises when output difference between the system observer and the original system is forced to go to zero in finite deadbeat convergence time. That mentions partly that at the same time the identified transfer function of original system through calculated from the state of system observer becomes equal the real transfer function of original system.
(2) Particularly at the time when identiability condition holds, there exists a class of state stagnant system such that the state of system observer converges to the modified form of original system.View full abstractDownload PDF (833K) -
Hiroyuki KAJIWARA, Katsuhisa FURUTA1984 Volume 20 Issue 1 Pages 16-21
Published: January 30, 1984
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper is concerned with the sensitivity problem for linear time-invariant multivariable feedback control systems. Based on the theory of perturbation bounds for pseudoinverse matrices, it is shown that the sensitivity property depends upon, not only the smallest singular value of the return difference matrix T, but also the condition number of T, i. e., the ratio of the largest singular value of T to the smallest singular value of T. In order to achieve lower sensitivity, the smallest singular value of T should be larger and the condition number of T should be smaller.View full abstractDownload PDF (724K) -
Kazumi HORIGUCHI, Nozomu HAMADA1984 Volume 20 Issue 1 Pages 22-28
Published: January 30, 1984
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSRecently with the enlargement of plant's scale, model reduction is becoming much more important and many methods are studied in control system design.
The methods of order reduction for linear systems are divided into two groups. One treats transfer functions and the given high-order transfer function is approximately reduced to a low order one. On the other hand, the second method reduces its state space model by state aggregation. The latter method would be preferable in many practical viewpoint.
At present, many reduction techniques have mainly dealt with continuous-time systems and there are few for discrete-time systems.
Considering these situations, this thesis aims at proposing two reduction methods for linear discrete-time systems via state aggregation. We established the following methods:
i) Reduction based on discrete-Schwartz form,
ii) Reduction based on discrete-Routh form.
i) is a time domain approximation method, while ii) is a low-frequency domain one. Both of them assure the stability of reduced-order systems, and are performed by simple algorithm.View full abstractDownload PDF (838K) -
Hirotaka NAKAYAMA1984 Volume 20 Issue 1 Pages 29-35
Published: January 30, 1984
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn recent years, many kinds of interactive methods for solving multiobjective decision problems have been developed. Many of them require high degree of judgment to decision makers, for example, marginal rate of substitution or ordering among a set of alternatives, and a number of auxiliary scalar optimizations. These features make their application to practical problems difficult. In this paper, a new type of interactive method, called satisficing trade-off method, will be proposed. The method is very simple and easy to carry out, and therefore is expected to be applied to many practical fields.View full abstractDownload PDF (1013K) -
Keiji HASHIMOTO, Hidenori KIMURA1984 Volume 20 Issue 1 Pages 36-42
Published: January 30, 1984
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn digital control systems, the execution of the control algorithm inevitably generates the rounding error due to the finite word length of the register of the digital controller. If the control performance is expected to be high, the effect of rounding error should be estimated quantitatively, especially when the register word length is small. In this paper, the effect of rounding error based on floating point arithmetic is investigated for the finite settling-time control algorithm, which is the most popular method of digital control. A theoretical error bound is derived based on the statistical analysis of rounding error. The validity of this bound is exhibited experimentally by hybrid simulations for a second-order and a third-order systems.View full abstractDownload PDF (846K) -
Toshio ENDO, Yasuyuki FUNAHASHI1984 Volume 20 Issue 1 Pages 43-48
Published: January 30, 1984
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDue to the nonlinearity of thermal constants such as specific heat, difference equations are used mostly to predict the heating temperature of slabs in the furnace. The difference equation approach entails time sharing, and thus vast amount of recursive computation is required to perform the calculation of heating temperature of slabs by means of difference equation. As a result, the difference equation approach has a defect in long computation time. This drawback becomes a great obstacle when the difference equation approach is used in the application of on-line predictive control of heating temperature of slabs in the furnace.
Instead of the difference equation approach, the authors proposed a fast algorithm for the prediction calculation of heating temperature. The algorithm uses analytical solution but is recursive in nature and takes into account the nonlinearity of thermal constants.
Analytical solution is represented by a sum of infinite series. For the practical use of predictive computation, the infinite series must be approximated by a finite series. There is a trade-off between the speed of computation and the accuracy of result. To retain the fastness of computation, dimension of the finite series must be low as possible. For the accuracy, higher dimension is desired. As such, the dimension of the approximate finite series must be of minimum, while guaranteeing the required accuracy.
In this paper, a simple but useful relationship is derived which relates the finite series approximation of the heat conduction equation and its computational accuracy. A criterion on the dimensional reduction is also proposed. The criterion proposed is applied to the prediction calculation of heating temperature of a billet in a continuous furnace. Calculated temperature is compared to the measured temperature of the billet. It is assured that the fast calculation algorithm and the criterion on order reduction proposed in this paper are of practical use.View full abstractDownload PDF (770K) -
Kentaro YAMAGISHI, Sadao FUJIMURA, Hiromichi TOYOTA, Minoru INAMURA1984 Volume 20 Issue 1 Pages 49-55
Published: January 30, 1984
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSProposed is a new type of discriminant function for classification of multispectral images. This uses both the mean and dispersion in each spectral channel obtained from a very small image area (subimage). The function is based on Neyman's ‘smooth’ test, which is a nonparametric test of a distribution model. Its performance is compared with those of one based on Kolmogorov Smirnov test and other discriminant functions by real multispectral image data in terms of classification accuracy and robustness for variation of training data. The comparison shows that
(1) this is quite efficient when variances of the data are largely different from one category to another, and that
(2) this is robust for variation of training data, but not very robust for a bias of mean caused by samples not representing the category.View full abstractDownload PDF (2595K) -
Takashi OMORI, Kaoru NAKANO1984 Volume 20 Issue 1 Pages 56-63
Published: January 30, 1984
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper describes a model of a visual neural system of a higher animal with self-organizing property. In the human brain, a model of outer world is gradually constructed through experience. We call it “World Image”. It contains not only knowledge of objects but also models of space and/or action etc. We get information of outer world through receptors such as eyes and ears, and interpret it referring to “World Image”. Then new and important information is appended to “World Image”. Human brain contains a large number of neurons and most of which have similar structures. That is, “World Image” is represented as the form of neurons and their interconnections. To study how the brain realizes “World Image” is very important not only academically but also technologically, because of the recent great progress of micro electronics. At the first step of studying “World Image”, this paper describes a summary and a model of a visual neural system of a higher animal, and at the second step describes experimental result by a simplified hardware model made for trial.View full abstractDownload PDF (1689K) -
Kensuke HASEGAWA, Takashi MIZUTANI1984 Volume 20 Issue 1 Pages 64-70
Published: January 30, 1984
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe authors have so far proposed the multivariable servomechanism with the function autonomously to generate the trajectory according to the nominal path for the purpose of the trajectory control of a manipulator. We call it Autonomous Trajectory Generating Servomechanism (ATGS).
The paper deals with the analysis of the stability condition of the parameters in ATGS and the characteristic improvement of the trajectory generated by ATGS for raising the stability and the accuracy of the trajectory.
At first, the fundamental algorithm of ATGS is formulated in general. Then, the stability analysis on both the continuous data and the discrete data ATGS is given based on the formulation. By the results of the analysis, we showed the stability condition of the parameters in ATGS as the chart.
Next, we introduced P-D control to ATGS as the strategy to improve the trajectory characteristics and analyzed the effects on the trajectory stability and accuracy. By the analysis, it is clarified that P-D control can raise the stability and the accuracy.
However, from the point of view to clarify the fundamental features of ATGS, we analyzed limitedly the characteristics for the planary trajectory assuming that ATGS was to be applied to the trajectory control of the Cartesian type manipulator.View full abstractDownload PDF (750K) -
Koichi ITO, Shinsuke AKAGI, Hiroshi BANDO1984 Volume 20 Issue 1 Pages 71-77
Published: January 30, 1984
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe objective of this paper is to develop a computer-aided optimal planning method for designing a marine heat and power generation plant which is composed of combining Diesel and turbogenerators, an exhaust gas economizer, auxiliary boilers and so forth. As there exist many alternative combinations concerning generators and boilers in constructing the above-mentioned plant, it is important to determine the system's construction properly by selecting total numbers and scales of respective generators and boilers so as to optimize the long-term economy of the plant.
In this planning system, several design conditions are first set which are necessary for the planning of the objective plant; i.e., several voyage patterns are set based on ship's operational condition, and both energy demands and steam output from an exhaust gas economizer are estimated for each voyage pattern mentioned above. Next, setting an alternative plant composed of combining generators and boilers adequately, the optimal operational policy for each voyage pattern is determined by minimizing the fuel cost under several physical constraints based on linear and quadratic programming methods. Considering the results obtained above hierarchically, the annual capital and operational costs of each plant are calculated, and the best system's construction is lastly determined by comparing economy of all alternative plants.
A numerical study has been carried out on a plant of a high speed container ship planned actually, and it is ascertained that the optimal planning method proposed here is advantageous to find best construction of the objective plant compared with the conventional trial and error method.View full abstractDownload PDF (1000K) -
Shigeoki HIRAI, Tomomasa SATO1984 Volume 20 Issue 1 Pages 78-84
Published: January 30, 1984
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA master-slave manipulator (MSM) is one of the most important teleoperators for performing tasks in hazardous environments where human beings cannot enter. However the MSM is not easy to operate, even for trained persons.
In this paper, the authors propose the Language Based Master-Slave Manipulator (LBMSM) system, which introduces a description system of control schemes into the MSM system. The description system is implimented as a master-slave command language and the prototype LBMSM system equipped with the language is constructed.
The LBMSM system has the following features not possessed by conventional systems. 1) It can change kinematic relations between the master and slave manipulator by this command language. 2) It can reduce a complex task to a simple one by imposing motion constraints. The motion constraints are specified by the command language. 3) It can call a program control mode during master-slave control mode. The emphasis of this LBMSM system is on the uniformity of scheme description by the command language.
The decrease in conventional difficulties gained by use of the LBMSM system is demonstrated by experiments using the prototype system.View full abstractDownload PDF (2398K) -
Tsunehiro TAKEDA1984 Volume 20 Issue 1 Pages 85-87
Published: January 30, 1984
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDownload PDF (396K) -
An Expedient in Single Input Single Output SystemsTakahiko TSUJISAWA, Ryozaburo TAGAWA1984 Volume 20 Issue 1 Pages 88-90
Published: January 30, 1984
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDownload PDF (306K)
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