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Volume 13 (1977)
- Issue 6 Pages 533-
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- Issue 4 Pages 313-
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- Issue 2 Pages 105-
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Volume 13, Issue 6
Displaying 1-16 of 16 articles from this issue
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Yasuhiko TAKAHARA1977 Volume 13 Issue 6 Pages 533-538
Published: December 30, 1977
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper we introduce the concept of a basic linear system which is defined as a strongly stationary, output complete and strongly precausal time system with a finite dimensional system core, and investigate some properties of it. The concept is shown an axiomatized model of constant coefficient linear ordinary differential equation systems.
The main results of this paper are:
i) A reduced state space representation of a basic linear system is shown to be unique up to isomorphism. This implies an interesting fact that basic linear systems form a class of time systems whose state space representations are not arbitrary.
ii) As an application of i) controllability and stability properties are investigated in relation to system behaviors. As for controllability a controllability condition of a basic linear system is described in the term of the input output relation. As for stability we intoroduce the concept of output stability as a stability concept concerning system behaviors and show that the output stability implies and is implied by the traditional state space stability for a basic linear system.
The above considerations lead us to the conclusion that the concept of basic linear systems is, although general and fairly abstract, structured richly enough to produce interesting results and that it can be fundamental conceptual framework for linear systems theory.View full abstractDownload PDF (929K) -
Shigeru OHMATSU, Hiroshige NAGAMINE, Takashi SOEDA1977 Volume 13 Issue 6 Pages 539-546
Published: December 30, 1977
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper treats the fixed-interval smoothing problems for a linear stochastic distributed parameter system with a noisy observation at discrete points on the spatial domain or its smooth boundary. The new feature of this paper is that the derivation of the optimal fixed-interval smoothing estimator is based only on the Wiener-Hopf theory. Combining the Wiener-Hopf equation for the optimal smoothing problem with that for the optimal filtering problem, we construct the optimal fixed-interval smoothing estimator which was derived before by using the Kalman's limiting procedure. Furthermore, we derive the optimal estimation error covariance function for the fixed-interval smoothing problems by using the properties of the fundamental solution for the differential operator. Finally, for the convenience of the numerical computation, we rewrite the results obtained here for the distributed parameter system by using the Fourier expansion method.View full abstractDownload PDF (874K) -
Mitsuo WADA1977 Volume 13 Issue 6 Pages 547-552
Published: December 30, 1977
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, an optimal control problem of the tracking system and/or the regulator system with quadratic criteria is discussed. It is assumed that some preview information from the present time t up to ta is given with respect to a command signal and/or a disturbance. The preview information is utilized to decide the optimal control.
This problem called the optimal finite preview control problem is solved for the continuous time system. The optimal finite preview control is derived as a functional of the observed state ensemble signified previously, so a physically realizable control system is constructed. At the same time an expression for the minimum cost is derived in order to evaluate the control effort and the effect of preview. From the result of the paper, it is shown that the preview is effective and also the effect of preview can be numerically evaluated.View full abstractDownload PDF (796K) -
Eigenvalues-Eigenfunctions ApproachMasanori SUGISAKA1977 Volume 13 Issue 6 Pages 553-560
Published: December 30, 1977
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSUtilizing the theory of invariant imbedding and Karhunen-Loève expansion, an initial value system suitable for real-time calculation is presented for the solutions of the vector-matrix Fredholm integral equations of linear least squares estimation theory when the signal processes are nonstationary. And a new Wiener-type filter using sequential calculations of eigenvalues and eigenfunctions is proposed.
In no few systems for control or communication, the information on convariance is more readily available concerning the signal processes than the state space model. Therefore, under the assumption that the kernel matrices of the Fredholm integral equations, which correspond to the covariance (correlation) matrices of the signal processes, are known a priori, the filtering and fixed-point smoothing algorithms are derived for the estimation problem of the signals with semi-degenerate kernels, using the nonminimal covariance factrization technique showed by R. Brockett and the series expansion of the kernel matrix by vector orthonomal eigenfunctions (Karhunen-Loève expansion).
In Appendix the initial value systems for a degenerate kernel and a signal process with band-limited spectrum are briefly given for the scalar estimation problem to show the applicability of the derived algorithms for various types of kernels.
Some simulation results from the signal processes with semi-degenerate kernels are given.View full abstractDownload PDF (1002K) -
Kiyotaka SHIMIZU, Eitaro AIYOSHI, Tetsuo UENO1977 Volume 13 Issue 6 Pages 561-568
Published: December 30, 1977
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWe are concerned with a class of organizations composed of a coordinating central system and plural semi-autonomous subsystems, such that each of them has a decision-making unit. Such a problem is regarded as that of a decentralized two-level optimization. The basic principle of planning for this organization is that the central system allocates resources so as to optimize its own objective, while the subsystems optimize their own objectives using the given resources.
Within this framework of decision making, we consider a transportation problem in which N transport agents transport their own commodity. Each transport agent n, n=1, …, N, finds optimal flow patterns of the associated commodity n so that the transportation cost is minimized based on its own objective function under the arc capacity restriction imposed by the central agent. The coordinating central agent governs the transport agents through the way of allocating the arc capacity so that the optimality of whole network system is achieved. Here, the lower level problem is composed of a set of single commodity minimum cost flow problems of the transport agents, each of which can be easily solved separately by the subsystem.
The decentralized optimization problem is solved in principle by a parametric approach. A feasible direction algorithm using directional derivative and application of a constraint simplex method are proposed to solve the formulated network flow problem.View full abstractDownload PDF (1060K) -
Yasutaka HAYASHI1977 Volume 13 Issue 6 Pages 569-574
Published: December 30, 1977
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn a PWM (pulse width modulated) control system with an actuator, the control performance expressed in terms of indices such as accuracy and settleing time often declines when the involved static frictional force is larger than the dynamic frictional force. To prevent this decline an effective control method has been proposed to provide a set of plus and minus pulses switching their polarity over at each initiation of actuator movement. In any set of pulses, the width of the first pulse is restricted by the condition that the pulse polarity must be switched over at the moment the actuator begins to move. The width of the second pulse, however, can be suitably selected to minimize the criterion function of the system. This paper deals with the computational analysis of the minimization of the function. In the first places, the width of each second pulse is slightly deviated from a given nominal valve. And resultant deviations of the state variables are computed. In the computation, the problem of discontinuity arises in the static-to-dynamic transient stage of the actuator motion. Yet, a simple approximation method has been devised to deal with the discontinuity. The deviation of the criterion function corresponding to that of each pulse width can be determined from the results of the state variable deviations over the range to the final time. The ratio of the two deviations is used as the gradient for computation. The width of the each second pulse is slightly modulated in proportion to the gradient. The modulated pulse is regarded as a new nominal pulse. Such a modulation is repeated until the optimal control pulse sequence is attained.View full abstractDownload PDF (634K) -
Hiroshi KASHIWAGI, Masato SAKATA, Akira MISAO1977 Volume 13 Issue 6 Pages 575-579
Published: December 30, 1977
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper describes a new method for obtaining a pseudo-Gaussian signal by simply low-pass filtering an antisymmetric m-sequence. Theoretical considerations show that the skewness of amplitude distribution of the obtained signal is always zero and the kurtosis can be calculated for each characteristic polynomial generating the m-sequence.
The theoretical kurtosis is calculated and shown in Table 1 for each of the characteristic polynomials having 3, 5 or 7 terms, in the range n=17 to 34, where n is the order of the m-sequence.
Table 1 shows that, in order to obtain a good pseudo-Gaussian signal, we should use those characteristic polynomials which consist of 5 or 7 terms, because the kurtosis for 3 term polynomial is much larger than 3, the value for a Gaussian signal.
Results of hybrid simulations show good agreements with the theoretical considerations. The skew, kurtosis and χ2 tests were performed on the signals obtained in the simulations and the tests show that the signals are considered to be Gaussian within the 0.01 significance level.View full abstractDownload PDF (1228K) -
Tsuneo YOSHIKAWA1977 Volume 13 Issue 6 Pages 580-586
Published: December 30, 1977
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper considers the question: “When can a dynamic team problem be decomposed into several smaller dynamic team problems?” The team is partitioned into several groups of members. Precedence relation and nestedness relation of information among these groups are defined. Then the concepts of independent partition and sequential partition of a team are introduced, which are partitions satisfying some conditions on their precedence relation, nestedness relation, and cost function. It is shown that if a team has an independent (a sequential) partition, the problem can be decomposed into several independent (related) subproblems. A finite team problem with four members is solved numerically to illustrate the application of the above result.View full abstractDownload PDF (374K) -
Hideo HANAFUSA, Haruhiko ASADA1977 Volume 13 Issue 6 Pages 587-594
Published: December 30, 1977
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe force controlled robots can recognize the relations between their hands and the external objects, directly or indirectly, by measuring the elastic distortions of their wrists or arms, and can adapt themselves to unknown situations. For example, in the assembly process where the robot inserts a peg into a hole, a reaction force from the peg implies an indication of how much the peg is off the center while being pushed into the hole.
In such a case, if not only the prehension force but also the prehension stiffness are variable, the force controlled robots will be versatile. We propose a robot hand of which the prehension stiffness is adjustable, according to the shape of a work piece and the content of a job. Our robot hand has three elastic fingers, where each finger can be individually driven by a pulse motor through a coil spring. And the apparent stiffnesses of the coil springs are changeable arbitrarily, by the special control algorithm of finger forces.
After describing the algorithm, the analysis of the prehension system and the physical meaning of the system parameters are discussed. Subsequently we derive the method of the parameter adjustment in order to realize arbitrary prehension forces and stiffnesses. Finally the theoretical results and the usefulness of this control method are confirmed through the experiment by the developed robot hand.View full abstractDownload PDF (527K) -
Kazuo TANIE, Susumu TACHI, Kiyoshi KOMORIYA, Minoru ABE1977 Volume 13 Issue 6 Pages 595-602
Published: December 30, 1977
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe electrocutaneous communication by means of electric pulse stimuli has been studied. One of the most important problems in this kind of research is to determine the most relevant stimulus parameters for transmitting the information. These parameters are called informational dimensions of stimuli. In general, they consist of three factors: namely, frequency, space and magnitude. The frequency and the space dimensions are said to correspond to the pulse interval of stimuli and the number of electrodes, respectively. For the magnitude dimension, however, it had not been clarified which parameter is the most relevant.
In the previous paper we studied this problem and found the fact that the subjective magnitude of electrocutaneous stimuli is related to the pulse energy. This paper describes some problems about the constant energy electrocutaneous stimulation, namely, the design of energy measurement instrument, the measurement of energy threshold characteristics as a function of time, and estimation of the channel capacity from the measurement of a just noticeable difference.
The energy threshold, the current threshold and the pulse interval characteristics were measured as functions of time, using the constant energy stimulator designed by ourselves. It was found that the energy threshold remains constant with time, while the current threshold increases gradually with time. These results suggest that the magnitude sensation is more closely related to the pulse energy than the pulse current. Moreover, the channel capacity estimated from the measurement of a just noticeable difference was found to be 3.0 bits to 4.0 bits for five subjects.View full abstractDownload PDF (624K) -
Noboru NAKATANI, Takaharu KONISHI, Tomoharu YAMADA, Toshiya SAKABE1977 Volume 13 Issue 6 Pages 603-608
Published: December 30, 1977
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSTo measure non-stationary flow in fluidic elements, a new type laser Doppler velocimeter was developed with variable frequency shift and by the use of a frequency tracker. The frequency tracker provides a real time demodulation of the FM signal and yields an analogue signal continually which is proportional to the component of the local fluid velocity to which the optical system is sensitive. However, the measurable variation of the Doppler signal frequency is limited by the dynamic response of the frequency tracker. To give more allowance to the limitation of the frequency tracker, the mean frequency of the Doppler signal was shifted up by two acousto-optic modulators. So the width and the frequency of the signal frequency variation were kept within the measurable range of the frequency tracker.
Using this laser Doppler velocimeter, firstly when a step flow appeared in the main nozzle with and without a control flow, the transient responses of flow velocity at the points near the jet attached wall were measured. Without a control flow the velocity fluctuates but later becomes constant. With a control flow the velocity becomes constants in about 1/20 of the time experienced without a control flow. Secondly the switching characteristics of the attached jet with a control flow were studied in the fluidic elements with and without a cylinder in the main nozzle. The switching speed in the element with the cylinder becomes faster than that in the element without the cylinder. Lastly, to investigate the mechanism of the faster switching, the turbulent power spectra in their elements were obtained from the Fourier transform of the autocorrelation functions of the velocity fluctuations. In the element with a cylinder, the turbulent scale becomes larger than that in the element without a cylinder. As the large-scaled turbulence diffuses the attached jet, the jet becomes wider and draws near to the wall of the fluidic element. This makes the switching speed faster.View full abstractDownload PDF (746K) -
Takemi INOUE, Kyohei YAMAMURA, Toshio NEMOTO1977 Volume 13 Issue 6 Pages 609-614
Published: December 30, 1977
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn the precise measurement of RF (Radio Frequency) power, a calorimeter system is often used.
Here a calorimeter system was designed, composed and experimented to determine the effective efficiency of bolometer mounts in the 100GHz frequency band.
This system is made up of thermo-electric detecting and cooling elements, an auxiliary heater, a new circular bolometer mount and other supporting components. A circular waveguide is used in the system as an RF power guide line to reduce a measurement error due to waveguide loss.
As the result of the error estimation, the measurement accuracy of ±0.49% is obtained.View full abstractDownload PDF (465K) -
Ichiro NAKATANI, Tomoyuki IZUMISAWA1977 Volume 13 Issue 6 Pages 615-621
Published: December 30, 1977
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper describes the experimental method for determining and controlling satellite attitude using a simulator. The simulator utilizes a satellite model supported by an air-bearing. A mini-computer is used in an on-line mode for processing data from the sun sensor and the earth sensor and for calculating the timing of gas jet firing.
The software system for the attitude determination and control of a spinning satellite in a geostationary orbit was tested by the above mentioned apparatus and its performance was confirmed.
The attitude determination program adopts the Kalman filter technique. The effect of attitude drift due to the earth rotation and gravity is taken away from the raw data. The attitude control program adopts the Rhumb line method and the great circle method.View full abstractDownload PDF (377K) -
Teruhiko OHTOMO, Yasutoshi TANAKA, Takao OHUCHI1977 Volume 13 Issue 6 Pages 622-629
Published: December 30, 1977
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe objective of this study is to simulate the memory holding characteristic of the pulse width modulator (PWM) for nondestructive readout which has been proposed as an analog core memory. This characteristic is represented by the percentage difference of the output pulse width versus the number of readout. It is showed by a saturation curve, and gives a significant clue to a designer of the modulator.
By measuring various hysteresis loops of the two-hole core, it is confirmed that the nature of saturation depends upon the hysteresis phenomenon due to the roundabout flux toward write-in leg during a readout operation. The transfer model of the flux level in PWM is proposed by taking into consideration the flux pattern at every readout and the hysteresis model of partial flux reversal proposed by Harada. The recurrence equations for the output pulse widths are derived from the model, which is based on the assumptions that the slope of the irreversible region declines in proportion to the reversed flux level and that the threshold level changes gradually. The characteristic is calculated by a computer, and then it is confirmed that the model can well express the complicated transfer of the flux in PWM.View full abstractDownload PDF (1067K) -
Yoshimi MAKINO, Tsunehiro MARUO1977 Volume 13 Issue 6 Pages 630-635
Published: December 30, 1977
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSRecently, we have reported on a new magnetic field sensor having a pair of sensing elements fabricated in the turnup line shape, and made of thin Ni-Co ferromagnetic alloy film. This sensor was built in non-contact magnetic switches available in the market.
When this sensor is applied for detecting the periodical magnetic signals to be conveniently used in the automatic control systems, the output voltages of the sensor have a double frequency, and are of the magnetic flux response type. From the theoretical analysis on the output voltage, it is found that the wave form is nearly sinusoidal under the following conditions; 1) the dimensions of sensing elements are sufficiently small compared with the wave length (λ) of the periodical magnetic signals, 2) the sensing elements are kept at a distance of about (1/5) λ from the plane of the magnetic signals.
In order to obtain a more complete sinusoidal wave form, it is effective to place the pair of sensing elements at a distance of (1/2+n)λ/2. A theoretical analysis showed that the output voltages of the improved sensor are completely sinusoidal, and have a larger amplitude compared with that of anon-improved one.
An improved sensor was manufactured for trial, and applied for detecting the positions of writing in a discharge type printer. The positions of character were successfully controlled for practical use.View full abstractDownload PDF (338K) -
Osamu OYAMA1977 Volume 13 Issue 6 Pages 636-641
Published: December 30, 1977
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a new design of a pneumatic coupling condenser and experimental data of its performance. This device consists of three parts: an input chamber, a modulating chamber and an output signal transmitter. The modulating chamber is a thin cylindrical chamber which is confined with a diaphragm at each side and has a vent equipped with a restrictor. The output signal transmitter is merely a usual pneumatic micrometer (back-pressure type) which transduces a displacement of the center portion of the output diaphragm into an output signal.
Features of this device are shown as follows.
1) An input impeadance to a signal flow is infinite.
2) Output signals contain no direct flow components of input signals.
3) In the frequency response, the gain is independent of the vent resistance in the frequency range well above the break-point frequency and the break-point frequency is inversely proportional to the vent resistance.
4) This device acts as a low-cut and highpass filter.
5) This device has a differentiating function.
The frequency responses of the models equipped with laminar vent restrictors and orifice are measured. In the case of the laminar vent restrictor, the experimental values are compared with the calculated ones. The results show a good agreement.
Furthermore, the effects of design parameters on the characteristics of a pneumatic coupling condenser are discussed.View full abstractDownload PDF (699K)
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