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Volume 18, Issue 10
Displaying 1-14 of 14 articles from this issue
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Hidenori KIMURA, Osamu SUGIYAMA1982 Volume 18 Issue 10 Pages 955-960
Published: October 30, 1982
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper proposes a procedure for recovering asymptotically the robustness of the optimal output feedback system via perfect regulation and perfect observation. The duality between the perfect regulation and the perfect observation is fully exploited to treat both of the return difference matrices at the plant input and at the plant output. Explicit expressions of these return difference matrices are derived and their asymptotic properties are examined. A simple algorithm for perfect regulation is given based on the coprime matrix fraction description. Some numerical results are given to illustrate the theory.View full abstractDownload PDF (705K) -
Atsuhiko NODA, Tetsuo WAKABAYASHI, Yukio HATOYAMA1982 Volume 18 Issue 10 Pages 961-966
Published: October 30, 1982
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA fast recursive method has been proposed to identify the dynamics of a linear system. The characteristics of the method was shown by computer simulation as well as qualitative investigation.
There are some robust recursive methods for single input, single output, linear system identification using the vector model of discrete weighting function representation, such as the learning identification method. Although this method is stable against noise, it is not so fast at decreasing rate of identification error especially when the input is not white.
This defect could have been improved by Gauss-Jacobi method or Schmidt's orthogonalization etc., if it were perfectly noise-free. However, Schmidt's orthogonalization alone would make the identification process unstable in practical situation. This problem in adopting orthogonalization was settled by the proposed recursive identification method with adaptive nonlinear error-correcting term.View full abstractDownload PDF (748K) -
Toshikazu HIRASAWA, Katsuji UOSAKI1982 Volume 18 Issue 10 Pages 967-973
Published: October 30, 1982
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA recursive algorithm of stochastic approximation type is derived for the identification of the space-dependent parameters in a class of distributed parameter systems driven by random inputs. The algorithm uses noisy observations taken over at a finite number of equi-distant observation points located in a spatial domain through a linear observation system. The convergence of the estimates to the true parameters with probability one is proved using Ljung's theorem. Simulation studies exemplify good convergence property of the algorithm. The proposed algorithm is much more simple in structure, easier to implement, and less restrictive on system structure to apply the algorithm, compared to the algorithm of Kubrusly and Curtain, derived for the same situations.View full abstractDownload PDF (736K) -
Seiichi KAWATA, Hideaki KANOH, Masami MASUBUCHI1982 Volume 18 Issue 10 Pages 974-980
Published: October 30, 1982
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe relation between the spatial weighting function of a manipulated variable and the locations of the zeros is discussed for some class of first order partial differential equation system which are sometimes found in a single tube heat exchanger and many other industrial processes.
When the spatial weighting function is constant and the gain is high, the closed loop poles may become unstable, since the zeros exist in the neighborhood of the imaginary axis. It is found that the modification of the form of a spatial weighting function is desirable so as to move the zeros to the left on the complex plane.
When the spatial weighting function is linear and quadratic, the locations of the zeros move to the left on the complex plane as the magnitude of the spatial weighting function in the outlet is specified larger than that in the inlet. When the spatial weighting function is piecewise constant, some unmovable zeros exist in the neighborhood of the imaginary axis even if the magnitude of the outlet weighting is large. It is confirmed that the continuous gradient of the spatial weighting function plays an important role in moving the zeros to the left on the complex plane.View full abstractDownload PDF (882K) -
Case of the Retarded Type DelayYasuhiko MIGUCHI, Masao IKEDA1982 Volume 18 Issue 10 Pages 981-986
Published: October 30, 1982
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper considers the problem of stabilizing a linear time-invariant system with delay of retarded type x(t)=Ax(t)+Dx(t-h)+Bu(t), h>0, by means of a linear feedback Without delay u(t)=Kx(t).
The object is to obtain a sufficient condition less restrictive than those obtained so far for such stabilization.
The result is as follows. The system is stabilizable, if (i) (A, B) is a completely controllable pair, and (ii) when (A, B)is written in a canonical form of Popov or Luenberger, and D is divided by a certain rule, the norms of those parts of D satisfy a certain inequality.
In the previous results on this problem the restriction of the structure of coefficient matrix D has been put in the stabilizability condition. However, the constraint on the structure of the matrix is completely removed in this result.View full abstractDownload PDF (617K) -
Hidetoshi OHUCHI, Yo IKEBE1982 Volume 18 Issue 10 Pages 987-991
Published: October 30, 1982
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSRecently, the band width of electro-hydraulic servo component is required to be several hundreds Hz. Then it is necessary to clarify the dynamic characteristics of the element such as orifice in the component.
Responding to the above, the authors are carrying out the researches on the frequency characteristics between pressure drop (difference) and flow rate of the orifices.
Among the methods in the published literatures to measure the oscillatory flow rate, the apparently applicable one to our researches is the cylinder-piston type flow meter; in this method the detection of small pressure change in the cylinder chamber is required.
When the amplitude of the fluctuation is very small comparing with the (time) average of the pressure in the cylinder chamber, it is generally difficult to measure the fluctuating pressure accurately.
Accordingly, we cannot expect the accurate measurement of the oscillatory flow rate by the above method.
Then, we have developed new method. This paper shows our new method to measure the oscillatory flow rate.
This is a cylinder-piston type flow meter including the regulating means suppressing the pressure fluctuation in the cylinder so as to avoid the measuring error resulted from the compressibility of the fluid in the cylinder chamber.
As a result of the above mehtiond, the flow rate is obtained directly from the piston velocity.
Moreover, in this paper, the results of measurement of the frequency characteristics of various orifices as examples of the application of this method are shown.View full abstractDownload PDF (694K) -
Nobuo KURIHARA1982 Volume 18 Issue 10 Pages 992-998
Published: October 30, 1982
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a new method for the design of Walsh to Fourier Transform (WFT), and discusses its application to vibration diagnosis of rotating machinery.
W-FT is faster than the Cooley-Tukey FFT when the number 2n of sampled data is small or when the number of Fourier components is relativery small compared with 2n. However as the number 2n increases, the W-FT program size expands rapidly, because the program requires 2n×2n matrix Ci, k to convert Walsh components to Fourier components. Thus the implementation of the program into a micro computer is impractical when 2n is large.
To solve the above problem, a simplified algorithm of W-FT is derived. Namely, its linear conversion matrix Ci, k is expressed by Walsh matrix and Fourier matrix. First, WFT algorithm is improved, by using orthogonal relations between sinusoids and Walsh functions. And 2n×2n matrix is reduced by dividing the matrix into 2p-2×2p-2 submatrices C(p)s(i), s(k) which are independent each others, and by deleting zero submatrices among them. Next, when p is large, the elements whose values are small are deleted. As the result, the number of elements of C(p)s(i), s(k) are reduced by 2/3 and the time to calculate is shortened so as to meet for practical use.
From the simulation results of vibration diagnosis for turbine and generator, it was shown that the improved W-FT, presented in this paper, was faster than FFT by 3/4.View full abstractDownload PDF (965K) -
Hiroshi KASHIWAGI, Hiroshi HARADA1982 Volume 18 Issue 10 Pages 999-1004
Published: October 30, 1982
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper proposes a new concept on the phase property of an M-sequence, called cyclotomic phase, which is very useful in studying the phase properties of the M-sequence.
M-sequence is widely used as a pseudo-random signal, because its properties over the period look like those of a truly random signal. However, when we use a high-order M-sequence for generating pseudo-random numbers, we can use only a part of the M-sequence which may not be quite random. In these cases, we need the partial properties of M-sequence which depends on its phase.
The authors first study a method for obtaining the square root of a polynomial over GF (2), and then defines the cyclotomic phase as 1/2i (i: integer) point of the period. It is shown that the remainder polynomial of x2-i modulo f(x), the characteristic polynomial of M-sequence, is easily obtained. If f(x) consists of a few terms, the remainder polynomials at the cyclotomic phases have relatively small number of terms, which shows that the partial properties at the cyclotomic phase resemble each other. The partial properties such as autocorrelation function, autocorrelation of run, distribution of run, and distribution of Tausworthe sequence at 5 cyclotomic phases and 6 other phases are investigated. The results show that the partial properties at the cyclotomic phases look similar compared to those at other phases.View full abstractDownload PDF (723K) -
Toyoo FUKUDA1982 Volume 18 Issue 10 Pages 1005-1012
Published: October 30, 1982
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn a hydraulic system, pressure surges occur during the transition from one steady state to another state. The pressure waves travel at speeds close to the sound waves. The pressurized water flow can be analyzed with the aids of propagation wave theory. The Bergeron-Schnyder relationship holds between pressures and flow rates at large interval of pipe line.
This paper developes a new concept of fault detection of pipe line based on the Bergeron-Schnyder relationship. Two criteria functions λ(t) and, μ(t) are defined which are calculated from real time measurements of pressures and flow rates, so as to detect whether the pipe line is sound or defective. When a break or leak occurs, the criteria functions give the informations that the pipe line is ‘abnormal’. It is shown that the break point can be located by two criteria functions and also leak flow can be estimated. For the purposes of feasibility, the three cases simulations are exemplified, which show the appropriate informations of the state of water pipe line.View full abstractDownload PDF (993K) -
Tatsuo ARAI, Eiji NAKANO1982 Volume 18 Issue 10 Pages 1013-1020
Published: October 30, 1982
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWhen used for the FMS (Flexible Manufacturing System) and for the automated hospital tasks, robots should move freely in order to improve their working ability or to increase their productivity. When a robot must move on a limited plane, it is able to carry out various kinds of locomotion if it can measure its position and direction in the coordinates fixed to this plane.
Generally the position (or location) and the direction of a robot can be calculated by using the principle of trigonometrical survey. In this method we use the values obtained by measuring the direction angle of three fixed points from the robot.
In this paper we will introduce the Measuring Equipment for Location and Direction (MELODI) which uses ultrasonic waves according to the above principle. Its basic characteristics and the algorithm for calculating the position and the direction will be explained.
The directions of three points should be measured at the same time in order to control the movement of the robot on real time. For this purpose, each fixed point has a speaker that transmits an ultrasonic wave of a different frequency. The measuring equipment is provided with three sensors that can receive the corresponding ultrasonic wave and follow the corresponding point independently.
From the experiment, the following observations have been made:
Each sensor can search for and locate the direction of the corresponding point correctly from the time the equipment is switched on.
It can follow the direction of the corresponding point accurately at the angular speed of 20 degrees per second.
Where the three points are set in the vertexes of the regular triangle with a 400cm side, the positional error is within about 5cm.View full abstractDownload PDF (1436K) -
Susumu SAITO, Toshimichi SAKAI1982 Volume 18 Issue 10 Pages 1021-1027
Published: October 30, 1982
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn fluidics, frequency demodulating circuits (f/a converters) have been used in temperature sensors and revolutional speed sensors. The conventional types of the circuits were constructed by using some fluidic devices which were connected by transmission lines, and the operating frequencies were usually under 1kHz.
In this experiment, the frequency demodulation was conducted by only one fluidic element and the frequency range was up to 10kHz without using beat frequency technique.
The developed element was constructed by acting the main jet of the first stage to the main jet of the second stage directly without transmission line. By this method, the element with excellent frequency characteristics was obtained.
A fluid signal genarator which was able to obtain high frequency fluid signals was also developed in this study. The signal generator produced up to 10kHz with a nearly constant amplitude.
By applying the fluid signal to the fluidic element directly without using beat frequency technique, the operation up to 10kHz was recognized. The output pressure change was about 17Pa/Hz.View full abstractDownload PDF (1503K) -
Seiji ISHIKAWA1982 Volume 18 Issue 10 Pages 1028-1030
Published: October 30, 1982
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDownload PDF (328K) -
Kazutada KOSHIKAWA1982 Volume 18 Issue 10 Pages 1031-1033
Published: October 30, 1982
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDownload PDF (1432K) -
1982 Volume 18 Issue 10 Pages 1035
Published: 1982
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDownload PDF (45K)
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