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Volume 25, Issue 7
Displaying 1-16 of 16 articles from this issue
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Min Cheol LEE, Nobuharu AOSHIMA1989 Volume 25 Issue 7 Pages 729-736
Published: July 30, 1989
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe signal compression method was applied for a measurement of impulse responses of nonlinear systems. The “impulse response” means the impulse response of linear element in the nonlinear system.
The experimental system (1) consists of a pendulum, electric magnetic valves and a computer. The pendulum is applied torque by air jet controlled by the electric magnetic valves. The experimental system (2) consists of 2nd-order electric circuits with dead band.
We could obtain the impulse responses of these systems free from nonlinear disturbance. System parameters were estimated by comparing measured Bode diagrams and those of models.
This method gave better results of identification than by least-square method and adaptive digital filter method. Discussions are made about possibility of applying this method to nonlinear control system identification.View full abstractDownload PDF (953K) -
Noriaki SOGAWA, Masao ARAKI, Satoru MORIKAWA1989 Volume 25 Issue 7 Pages 737-743
Published: July 30, 1989
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSFrequency analysis of annual maximum k(=1, 2, 3)-day precipitation in the Chikuma basin is considered by using c-histogram which can be applied even if maximum entropy distribution does not exist. The application study to the hydrological data shows that the c-histogram with 30 blocks and 3 moments gives good fit to the hydrological histogram and it estimates the suitable return period for maximum value judging from the number of data. Comparing with other distributions, the c-histogram estimates the large probable hydrologic variate in many cases which means the safety side in flood-control planning and the small standard deviation where the probability density of the right tail in the hydrological data histogram is large, though its log likelihood is smaller than those of other distributions. Besides the parameter identification time of the c-histogram does not depend much not only the number of given moments but also the number of blocks, and is much shorter than that of the maximum entropy distribution. The short calculation time for the estimation of the c-histogram is to be important when it is developed from 1-variate to multivariate.View full abstractDownload PDF (951K) -
Takao SASHIDA, Kenji MOTOSUGI1989 Volume 25 Issue 7 Pages 744-750
Published: July 30, 1989
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn order to evaluate humidity sensors aiming at the accuracy of ±1%RH, a humidity generator was made on the basis of the divided-flow method. By calibrating this generator with the standard humidity generator at NRLM through an optical dew-point hygrometer, its accuracy was confirmed to be ±0.6%RH (2σ) at the temperature of 20°C and in the humidity range of 20∼95%RH. This generator is now practically used as a part of automatic equipments for testing ability of accurate humidity sensors.View full abstractDownload PDF (1519K) -
Tsutomu MITA, Yuichi CHIDA, Jing Wen WANG1989 Volume 25 Issue 7 Pages 751-757
Published: July 30, 1989
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSFor past twenty years, the strictly positive real condition on the rational matrix F(s) is said to be equivalent to the condition FT(-jω)+F(jω)>0 (ω∈(-∞, ∞)), however, this is not true in general. This paper defines F to be pseudo-strictly positive real if it satisfies such a condition and shows that pseudo-strictly positive real condition is equivalent to strictly positive real condition if and only if DT+D>0 or (CAR)T+CAB<0 when det |D|≠0 or D=0, respectively.
This condition is deeply connected with the adaptive control and Popov's disk criterion, so the contents of this paper should give very important informations to the researches in these fields.View full abstractDownload PDF (885K) -
Ken-ichi OHSHIMA, Shin-ichi YAMADA, Hideji FUJIKAWA1989 Volume 25 Issue 7 Pages 758-764
Published: July 30, 1989
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA method for estimating the dynamics of a sampled-data system when it is operating under feedback control is proposed in this paper. This method does not require any special control action for the identification experiment. The theoretical analysis of the identifiability property of this method is also discussed. In this method, the input-output data is sampled at the frequency of which is a multiple of the control system's sampling frequency. It is proved that the condition for strong system identifiability depends only on rank of the pulse transfer function matrix of the feedback controller, for the feedback law is formulated in a periodic time-variant form in terms of the data. The model estimated from the data can be converted into the one available for the digital control of the system. It is shown that the conversion can be carried out with simple numerical operations, and a method for the fast conversion is also presented in this paper.View full abstractDownload PDF (774K) -
Makoto YOKOYAMA, Atsushi WATANABE1989 Volume 25 Issue 7 Pages 765-770
Published: July 30, 1989
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe measurement of the kernels of the Volterra series model of a nonlinear system is generally carried out as follows; first a parametric model is derived by applying orthogonal expansions to the kernels, and then the parameters are optimally determined in the sense of the least mean square error of the input/output experiments of the system.
In this method, if the input is a white Gaussian signal, the amount of computation required is greatly reduced whenever an arbitrary set of orthonormal functions is used for the expansion of the kernels. On the other hand, if the input is a stationary nonwhite Gaussian signal, the set of orthonormal functions cannot be taken arbitrarily for the purpose of computational reduction.
In this paper, the method of measuring the kernels, where an arbitrary set of orthonormal functions can be taken without the assumption that the input is white, is presented by applying Karhunen-Loeve expansion theorem. The key of the present method is that a nonstationary Gaussian random process is generated from an arbitrary set of orthonormal functions used for the expansion of the kernels and a set of uncorrelated Gaussian random variables, and it is used as the input.View full abstractDownload PDF (742K) -
Hiroshi ITOH, Takeshi TSUCHIYA1989 Volume 25 Issue 7 Pages 771-778
Published: July 30, 1989
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThese days, tracking control with high speed and high accuracy is seriously required in the field of robotics and machine tool. Until now, the control system has been synthesized by defining performance index including position error term on the trajectory in order to realize the purpose. However, satisfactory performance of the machine is not obtained because the position error does not represent the trajectory error which is to be really evaluated in the control problem, although it is deeply related to the trajectory error. In this paper, we propose new method in which the trajectory error area produced by the diference between the desired trajectory and the tracked one by the machine is evaluated in the performance index, and optimal preview control system is synthesized by means of optimal regulator theory. This system utilizes the future desired signal up to finite future time from present time. That means this system is preview control system. First, the control method evaluating the position error on the trajectory is discussed by exemplifying two-car tracking problem and the demerits to be overcome are pointed out. Then, concept of evaluating tracking error area is explained and proposed, and its formulation is discussed and it is shown that the trajectory error term is described by quadratic form with time varying coefficients. Next, the synthesis method of the preview control system with the trajectory error area term is presented. To evaluate the effectiveness of the proposed control system, simulation studies for two axis position controller are carried out.View full abstractDownload PDF (1050K) -
Masahiro OYA, Yukio NISHIMURA, Yoh YONEZAWA1989 Volume 25 Issue 7 Pages 779-785
Published: July 30, 1989
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper the authors consider design problems of controlled objects which are constructed by a cascade connection of a nonlinear element and a linear element, and propose a design method of the control system following a linear reference model.
The performance of the control system is measured by the state deviation between the object and the model. The convergence condition of the state deviation is relaxed in order to apply the design method to the practical object having such nonlinear elements as a deadzone and a backlash etc. Namely, on the basis of practical stability and exponential stability, the authors propose the design method in which the deviation converge to the any vicinity of the origin with rate δ of stability where rate δ of stability implies exp (-δt).
In the case where the states of the object can utilize directly, the state deviation is converged to any small region with any rate of stability. In the case where the states of the object can not utilize directly, estimated error of the observer is practical stable and the state deviation is converged to any small region with rate δ of stability where δ depends on the zero of nominal system of the object.
Finally, computer simulation results are presented to illustrate the effectiveness of the proposed method.View full abstractDownload PDF (773K) -
Iwao YAMAMOTO1989 Volume 25 Issue 7 Pages 786-791
Published: July 30, 1989
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDescribed in this paper, is a pneumatic logic device which functions as an exclusive-OR gate. Two same size of bellows are connected in series with a plate which closes movable ends of the bellows. A side plane of the plate has a rectangular shape, on which a groove is made longitudinally. The outlet of a rectangular nozzle faces the side plane at a small distance.
Fluid is supplied from a constant pressure source to the nozzle through an ejector-type throttle and it flows out to the atmosphere through the gap between the nozzle and its counter face. Inupt pressure signals are introduced in the bellows, and the pressure in the back-space of the ejector throttle is employed as the output of the device. When pressure in both of the bellows are equal, the outlet of the nozzle faces to the groove, and the pressure of the output chamber maintains low level due to the low fluidic resistance at the nozzle outlet. When a high level pressure is put into one side of the bellows and low level pressure is introduced in the other side, the plate displaces so as to cover the outlet of the nozzle with the side plane, and the output pressure maintains high level.View full abstractDownload PDF (802K) -
Toshihiro WATANABE, Hidefumi KOBATAKE1989 Volume 25 Issue 7 Pages 792-799
Published: July 30, 1989
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a study on the image processing method for recognizing small rounded opacities of pneumoconiosis in a digitized chest X-ray image and an automatic diagnostic system is also described.
A local processing filter which detects candidates of small rounded opacities of pneumoconiosis is proposed. This filter evaluates local density pattern of lung area and discriminates small rounded opacities from otheri rregular ones. After applying the local processing filter, revaluation of the density pattern of the neighboring region of each candidate is performed. Candidates whose neighboring density patterns are not consistent with those of small rounded opacities of pneumoconiosis are purged and the final results are obtained.
The latter half of this paper concerns with the automatic diagnosis of pneumoconiosis. The number of detected opacities per unit lung area, the total sum of their areas and so on are used as features for the categorization of profusion of opacities. Experiments to test the performance of the proposed system have been performed.
Zonal decision rates for normal/abnormal classification and for the four major category classification were 82 and 69 percent, respectively. Rates for overall film decision based on the majority rule were much higher than those rates. These experimental results show the effectiveness of the proposed system.View full abstractDownload PDF (2851K) -
Koichiro DEGUCHI, Takashi OKADA, Iwao MORISHITA1989 Volume 25 Issue 7 Pages 800-807
Published: July 30, 1989
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA new method for analyzing underground radar images and locating buried pipes is developed. Because the underground radar images are commonly blurred by peculiar noises, it has been hard to introduce an automatic analysis for detection of buried pipes.
For this problem, using Generalized Hough transformation technique, buried pipes are located from the radar image according to their characteristic forms of the images. By this method, the micro-wave propagation speed in under-ground can be detected simultaneously from the image, so their accurate locations can be obtained.
A speed-up technique for the calculation of the Hough transformation based on the gray levels and their gradients of the radar image is also developed. Good results of buried pipe location were obtained for some actual experimental under-ground radar images.View full abstractDownload PDF (2945K) -
Ichiro KIMURA, Jutaroh TADANO1989 Volume 25 Issue 7 Pages 808-814
Published: July 30, 1989
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSSimple and low cost robots have been developed for hospital use that, for instance, can guide patients and carry medical report files and a specimen rack for test tubes containing blood and urea to be analyzed.
A prototype (RS-I) with IC logic circuits and practical types RS-II, III, IV, V, VI with microcomputers have been made and compared in the use at the Saga Medical School Hospital.
The RS-I prototype was developed in 1984 and improved up to 1987. This is for experiments.
Now, in 1988, a RS-II is on daily work at the Department of Laboratory Medicine since August 1986, and a RS-V is also on daily work at the Paediatrics Ward since September 1987, both in Saga Medical School.
RS-I is driven by two DC micro-motors and 6 dry cell type Ni-Cd batteries, and is made of plastics, 60cm tall and 6kg in weight.
RS-II is driven by two DC geared motors and car use batteries, and is made of stainless steel and 100cm tall and 30kg in weight.
RS-V is driven by two DC flat motors and a car use battery, and is made of plastics, 100cm tall and 35kg in weight.
The robot can run following a guide tape which is 20mm wide and 100μm thick aluminium tape, detecting the tape by the use of four sensor sets consisting of a ultrared LED and a photodiode. It can proceed along a straight line with in angle error 5°, turn a rectangular corner at once, and when it detects the course end, do about-face-turn then stop waiting next start.View full abstractDownload PDF (2184K) -
Mitsuji SAMPEI, Masatoshi KAMEI, Matsuroh NAKAMICHI1989 Volume 25 Issue 7 Pages 815-817
Published: July 30, 1989
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, we will define an approximate input-output linearization problem for discrete time nonlinear systems. A modified structure algorithm will be proopsed to obtain the linearizing feedback.View full abstractDownload PDF (363K) -
Etsujiro SHIMEMURA, Kenko UCHIDA, Akira KOJIMA1989 Volume 25 Issue 7 Pages 818-820
Published: July 30, 1989
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSBy using Schumacher's method, a finite dimensional compensator is designed for a system with delay in states. It is also shown that the synthesis algorithm involves no difficulty of numerical calculation.View full abstractDownload PDF (400K) -
Mitsushi HINO, Zenta IWAI1989 Volume 25 Issue 7 Pages 821-823
Published: July 30, 1989
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper deals with an application of a simplified adaptive pole placement control algorithm to a design of active vibration control system. The algorithm is examined by several experimental results.View full abstractDownload PDF (406K) -
Masahiro INUIGUCHI, Yasufumi KUME1989 Volume 25 Issue 7 Pages 824-826
Published: July 30, 1989
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper deals with a multiobjective linear programming problem with interval objective functions. A possibly efficient solution is an extension of the efficient solution to multiobjective linear programming problem. A discrimination method of possibly efficient extreme points is proposed.View full abstractDownload PDF (394K)
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