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Volume 9 (1973)
- Issue 6 Pages 625-
- Issue 5 Pages 499-
- Issue 4 Pages 373-
- Issue 3 Pages 251-
- Issue 2 Pages 123-
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Volume 9, Issue 3
Displaying 1-17 of 17 articles from this issue
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Kamekichi SHIBA, Mikiya KAWAMURA1973 Volume 9 Issue 3 Pages 251-256
Published: June 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSAir temperature mesurement is very difficult because of the effect of radiation from surrounding bodies. The error due to radiation can be canceled by measuring the temperature with two temperature sensitive resistances of different emissivities.
The resistance thermometer here reported is designed to obtain the air temperature by a single measurement. This resistance thermometer needs no reference junction, different from the thermoelectric thermometer.
The thermometer is composed of two resistance elements covered respectively with different materials of different emissivities, and the two resistances are inversely proportional to the emissivities.
The difference of resistance of the two resistance thermometers gives the correct air temperature, the error due to rediation being canceled.
A modified Wheatstone bridge is used to measure the difference in resistances.
Three resistance thermometers composed of Cu, Ni and Pt respectively are examined. The experimental results show that the errors due to radiation can be reduced to less than 0.1°C between 35°C and 45°C.View full abstractDownload PDF (809K) -
Ryuichi MASUO, Chikayoshi MAEDA, Tadashi MIHUNE, Kazuo MURAKAMI, Michi ...1973 Volume 9 Issue 3 Pages 257-261
Published: June 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThere are two common methods for counting many small machine parts using a balance.
One of these consists of using a counting scale which has a large mechanical advantage l, and the other consists of repeatedly using a Roberval balance which has equal arm lengths. The former method counts (l+1)N parts directly, and the latter method counts 2nN parts after using the balance n times, where N is the initial number of parts.
The present paper is concerned with the analysis and with the comparison of the probability of miscount in these methods. The analysis is based on the assumptions that the distribution function of population of these many machine parts is always a normally distributive function which has a mean value w and a standard deviation σ, and that both types of balance are always accurate.
As a result of fundamental analysis based on elementary statistics, it becomes evident that the probability of miscount is far larger in using the counting scale than in using the Roberval balance. The probability of miscount in relation to the rsesultant number of parts is presented graphically for each type of balance.View full abstractDownload PDF (1040K) -
Tomokazu ARAI1973 Volume 9 Issue 3 Pages 262-269
Published: June 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper describes a cylindrical grid electrode designed for use in the capacitance or resistance method of measuring the electrical properties which are characteristic to the sample materials of powder and grain.
The cylindrical grid electrode is three cylindrical electrodes on a low loss insulator tube. The sample material of powder (or of grain) is placed in the cylindrical space surrounded by the insulator tube.
The characteristics of this electrode are measured by the capacitance change method and were discussed with the equivalent circuit. From the result, four detecting methods were found for measuring the electrical properties of powder and grain by this electrode, and the conditions for obtaining the maximum sensitivity with these methods were clearly stated.
Experimental results have shown that the moisture measuring method due to the capacitance measurement by this electrode for granulated sugar is difficult on account of the constancy of the capacitance within the necessary humidity range. Therefore, it became evident that the detection of a small moisture content in powder and grain must be done by measuring the high resistance.
The cylindrical grid electrode permits accurate non-contact measurements using a small volume of specimen and was found to give consistent results with a small variance, independently of particle orientations in the insulator tube.View full abstractDownload PDF (874K) -
Kensuke HASEGAWA, Hideo MAEJIMA, Tsutomu OHMAE1973 Volume 9 Issue 3 Pages 270-276
Published: June 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis study is concerned with simple eyes as one of the sensors for giving more adaptability to industrial robots. The purpose of this study is to discover the object by searching and to measure automatically its two-dimensional or spatial position before the robot goes into a handling operation. And, as the first step, the purpose of this paper is to construct the two-dimensional position detector and the spatial position measuring equipment.
Two methods are proposed in this paper, a method for detecting the two-dimensional position of an object using an ITV camera and, as its application, a method for measuring the spatial position of the object applying the parallax between a pair of ITV cameras. The characteristics of the equipment based on these methods are shown, and by a comparison between the theory and the experiments, the propriety of these methods is confirmed.
In consequence the two-dimensional position detector and the spatial position measuring equipment based on the methods proposed by the authors proved to be usable as the simple eyes of industrial robots by putting certain restrictions on the robots' environment.View full abstractDownload PDF (1372K) -
1973 Volume 9 Issue 3 Pages 276
Published: 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDownload PDF (113K) -
Yoshiaki TADOKORO, Tatuo HIGUCHI, Takeshi ANAYAMA1973 Volume 9 Issue 3 Pages 277-282
Published: June 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSMany digital filters for process control systems are used in low frequencies. These are not required to be very accurate, but only simple and handy. This paper describes a method for the construction of a digital filter suitable for an on-line process control environment. Magnetic elements are used as delay elements, which are the basic components of digital filters. The most important advantage of the magnetic delay element is the very long delay operation which is possible. This allows filters for very low frequencies to be constructed easily, with a great reduction in size as compared to that of analogue filters. And also, the magnetic delay element has high reliability in a wide range of environmental conditions, and is capable of isolating the input circuits from the output circuits.
As an example, the first-order low pass filters are constructed by the impulse invariant way and the bilinear transformation. The characteristics of these filters are examined. Consequently, it is clear that the errors arising from elements are about 0.3%, and these amplitude characteristics agree approximately with calculated results. In addition, the filter characteristics can readily be altered merely by changing the value of the coefficient or the sampling frequency.View full abstractDownload PDF (1347K) -
Akira KOBAYASHI1973 Volume 9 Issue 3 Pages 283-290
Published: June 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, the future value is taken up as a valuable bit of information concerned with an information synthesis for system automatization, and its measuring method is considered.
First, the measurement of the deterministic future state of a system is discussed for the case when the structure of the system is known and the disturbance does not enter into the system, putting emphasis on the distributed-parameter system. With this point, our discussion is quite different from Wiener's prediction problem.
The following fact is made clear for the case of the distributed-parameter system.
Since a significant inter-relation exists between space and time, the measuring system here becomes very simple compared with the case of the lumped-parameter system, and it is generally possible to extract the temporal information from the spatial information alone.
It should be noted that the preceding fact includes the conceptually expanded meaning of noncontact measurement in the sense that it enables us to measure at points where the real measuring devices are not or can not be provided.
Second, as an actual problem, the future value measurement of temperature is analyzed theoretically for a one-dimensional thermal diffusion system with heat transfer from the surface.
As a result, it is shown that the future value of temperature at a predetermined point can be determined from the present pattern of temperature distribution, and that it can also be given as a form of linear combination of spatially sampled values where a suitable spatial sampling method and interpolation function are obtained for this system
Finally, a simple measuring system based on the above theoretical conclusion is constructed using a round copper rod and some CA-thermocouples.
Experimental results show that the analysis is quite reasonable.View full abstractDownload PDF (1166K) -
Toshiro ONO, Hiyoshi OHKAWA, Kumeo NAKAJIMA, Yoshikazu SAWARAGI1973 Volume 9 Issue 3 Pages 291-298
Published: June 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper concerns an application-oriented study of improving the measuring speed and accuracy of an industrial weighing system from the viewpoint of modern control theory. The problem of improving the dynamic performance of the system has been formulated as a stochastic control problem, i.e., a linear regulator problem with inaccessible state variables and a noisy observation. A new concept of computer-aided dynamic measurement method has been proposed. Feasibility studies have been carried out by both computer simulation studies and on-line computer-control experiments. Results of feasibility studies give us several new and promising aspects of the present measuring method.View full abstractDownload PDF (2227K) -
Yasuhiko TAKAHARA1973 Volume 9 Issue 3 Pages 299-303
Published: June 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn modern systems theory dynamic systems are almost always treated by their state space representations. However, a state space, in general, cannot be uniquely determined by the external behavior (i.e., input and output) of a given system. This ambiguity of the state space may be one of the biggest difficulties of the theoretical aspect of the state space approach. In order to avoid this difficulty Mesarovic introduced the concept of a past determined system where the future output of the system is uniquely determined by the future input and by the past input-output pair. It was shown that a past determined system has a “natural state” which is uniquely determined from its external quantities.
In this paper we considered what kind of class of systems is past determined and gave necessary conditions and sufficient conditions for a general linear system to be past determined. In particular, we demonstrated that the classes of linear constant coefficient ordinary differential and difference equation systems are past determined. We also clarified the relation between the class of finite memory machines of finite automata and that of past determined systems, which may open a passage between the control theory and the automata theory.View full abstractDownload PDF (667K) -
Kaoru TAKANAMI, Masami ITO1973 Volume 9 Issue 3 Pages 304-310
Published: June 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn optimal regulator problems an increase in the value of the performance index (P.I.) is in general encountered when a Luenberger observer is employed to construct the estimates of the state-variables which are not available by direct measurement.
In this paper exp Dt (D: the coefficient matrix of observer) is studied with respect to the increase in P.I. and it is shown that for the case where n≥3 (n: dimension of the system), in almost all cases the increase in P.I. becomes arbitrarily large when the real parts of the observer eigenvalues become highly negative. Moreover it is discussed for what quadratic performance index the control law using the estimates of the state-variables is optimal. In this case, a sufficient condition is derived, and the relation between the weighting coefficients in the performance index and the eigenvalues of the observer is discussed.View full abstractDownload PDF (712K) -
Minoru HAYASE1973 Volume 9 Issue 3 Pages 311-319
Published: June 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSLinear constant coefficient optimum control problems with a quadratic cost functional which is not limited to be positive semi-definite are treated in this paper. If the quadratic cost functional is not positive semi-definite, then the problem often becomes a trivial one so that the problem can not be solved or the cost diverges to -∞. This paper shows the condition of the weighting matrices of the cost functional under which the problem has a nontrivial solution so that the constructed system is a stable one with constant coefficients, achieving the exact minimum of the cost functional.View full abstractDownload PDF (1023K) -
Sadayuki TSUGAWA1973 Volume 9 Issue 3 Pages 320-327
Published: June 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a design procedure for suboptimal quantizers of states in linear discrete feedback control systems and discusses the tradeoffs of the number of samples per unit time and the word length of digitalized states. In computer control systems of industrial processes, it is more efficient from the standpoint of computer control if the state signals or the error signals of the processes are taken in sparse samples and quantized coarsely, because the information load to be processed in the computer will thereby be reduced. On quantizing the sampled data, the usual uniform quantization is not necessarily suitable for transferring, processing and storing the data also for determining the control efficiently. The word length of the data can be shortened by the use of non-uniform quantization.
In this paper the process is described by linear differential equations and the cost functional is given by an ordinary quadratic performance index. This system is discretized by zero-order holding the control. The optimal control law is given by a linear combination of states, and the minimum cost is given by a quadratic form of states. When the sampled states are quantized, the control law is also given by a linear combination of quantized states and the minimum cost is approximated by a quadratic form of states. Then, the suboptimal quantizer is designed by minimizing the trace of the coefficient matrix of the cost with respect to input and output levels of the quantizer.
The suboptimal quantizer obtained here has a rather general nature depending only on the order of the processes. It quantizes the state finely near the zero and coarsely far away from the zero. In some 1st and 2nd order systems the information to be processed becomes about 20% less for the 1st order system and about 15% less for the 2nd order system with the suboptimal quantizers as compared with using the ordinary uniform quantizers.View full abstractDownload PDF (921K) -
Masaaki OHKOHCHI, Toshiyuki KITAMORI1973 Volume 9 Issue 3 Pages 328-336
Published: June 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a new method for constructing minimal state-variable models (minimal equivalent systems) of linear time-invariant multivariable systems of unknown structure from the input-output observation.
In contrast with earlier approaches which construct the model of all inputs and outputs in one phase, our method enlarges the model in multiple phases so as to satisfy the behavior of each added output variable.
The main results are as follows:
1) Multiple output systems are treated as a natural extension of a well-known single output system identification.
2) Minimal equivalent systems can be obtained in one of the canonical forms presented by Luenberger.
3) Systems with any initial state can be treated, so that minimal equivalent free systems can also be obtained by this method.
A method to transform the model into the Jordan canonical form is also considered.View full abstractDownload PDF (957K) -
Shoji TOMINAGA, Kokichi TANAKA, Seihaku HIGUCHI1973 Volume 9 Issue 3 Pages 337-344
Published: June 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn recent years, there have been many studies on the system identification problem, which is that of estimating the parameter vector from noisy observations.
This paper deals with the synthesis of an input signal for identification. The system considered here is a scalar input and scalar output discrete linear system with Gaussian additive noise on the observations. The synthesis of the input signal is to determine the input sequence which minimizes the estimation error, subject to a given amplitude-constraint on the signal. It is assumed that the system is being operated off-line during the identification procedure, so that the input is open to choice.
In this paper, the input sequence is chosen to minimize the determinant of the covariance matrix in the least square estimation error. It follows from the above result that the input sequence is given by the repetition of the uncorrelated sequences which take the maximum values under a given amplitude-constraint.
Next the realization of the sequences which satisfy the condition is treated as a block problem in combinatorial analysis. The block design is settled according to the number of unknown parameters. Then the input sequence may be obtained and is called the Uncorrelated Minimum Length Sequence.
Finally in the case of the low order system, these input sequences are shown in the list. The example demonstrates that estimation error decreases rapidly by the use of the sequences proposed here, which makes them effective in the system identification.View full abstractDownload PDF (850K) -
Setsuzo TSUJI, Hitoshi TAKATA1973 Volume 9 Issue 3 Pages 345-352
Published: June 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, two types of nonlinear filters which are constructed without the limitation of Gaussian distribution are presented for discrete noisy nonlinear systems. These filters are based on the nonlinear estimation theory derived by using the Hermite expansion or orthogonal projection method. In these cases, the a posteriori density functions, which are approximately represented by a finite number of terms, are modified so as to have the fundamental properties of a probability density function. Therefore, the merits of our filters are as follows;
1) Since the nonlinear theory is used and the moments are considered up to the higher order ones by the characteristics of non-Gaussian distribution, the filters enable us to estimate the states properly for systems with rather high nonlinearities.
2) One cause of divergence in estimation is eliminated by introducing the modified density function. In particular, negative values for the even moments (variance etc.) are avoided.
The simulation results by a digital computer indicate that these filters are superior to ordinary filters in performance.View full abstractDownload PDF (999K) -
Hiroyuki TAMURA, Norio TOGASHI1973 Volume 9 Issue 3 Pages 353-360
Published: June 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn recent years, computer-controlled public transportation systems have been studied as futuristic urban transportation systems.
In this paper, a mathematical model for the traffic schedule-control problem is built as a discrete state-regulator problem where the distance is chosen as an independent variable, and the deviations from the scheduled time intervals are chosen as the state variables. Computer simulations are performed for 3 kinds of line guideways using this model.
As a result, the control method proposed in this paper is found to be available for application to real systems.View full abstractDownload PDF (890K) -
Michio SUGENO1973 Volume 9 Issue 3 Pages 361-368
Published: June 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSLately, studies on fuzzy systems as well as applications of fuzzy set theory have attracted the attention of many researchers. The author has suggested the concept of fuzzy measure and fuzzy integral for representing fuzzy systems. The fuzzy measure without additivity may be regarded as a subjective one by which “fuzziness” is measured.
At first, this paper explains the fuzzy measure extended onto a family of sets including fuzzy sets and the concrete methods for constructing the fuzzy measure. As an example, the fuzzy measure gλ, -1<λ<∞, is defined and its characteristics are clarified. Here, gλ, corresponding to the probability measure when λ=0, is continuous for λ. Furthermore, the new concept of the λ-complement of a fuzzy set is proposed. This has flexibility due to the parameter λ. It is an extension of the complement defined by L.A. Zadeh.
Next, this paper considers the problems appearing when a human grades the similarity of several patterns with no sharp boundaries. The human decision mechanism is represented by a macro model where the fuzzy integral is used. Man's subjective characteristics in grading the similarity are obtained through the fuzzy measure identified so that both, human and model's, outputs agree with each other. A simple expriment on the above problem was performed. The experimental results show that the outputs of the model agree approximately with those obtained by human evaluation.View full abstractDownload PDF (1030K)
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