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Volume 30, Issue 4
Displaying 1-18 of 18 articles from this issue
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Hiromu INOUE, Hideki NINOMIYA1994 Volume 30 Issue 4 Pages 367-374
Published: April 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper describes non-contact inspection method using lasers and development of experimental setup.
An ultrasonic wave is generated when Q switched YAG laser is focussed on the surface of metal. Relations between the ultrasonic amplitude and the focussed laser density are measured and the optimum condition is found experimentally. Wave form detected by ultrasonic transducer is compared with wave form detected by experimental setup. Characteristic of demodulator and frequency characteristics of band path filter in experimental setup are adjusted to be same wave forms. Consequently, the ultrasonic echo of a small hole in a test metal can be observed.View full abstractDownload PDF (2835K) -
Yoshikazu NISHIKAWA, Jing-Long WU, Hajime KITA1994 Volume 30 Issue 4 Pages 375-384
Published: April 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSRegarding the color vision of human being, the zone theory which combines the three-component and the opponent-color theories of color vision has become widely accepted.
As physiological fact, there exist several types of ganglion cells in the retina which have different sizes in the center-surround structure. Hence it is important to investigate the spatial characteristics of the color processing system.
In the present paper, the authors measure the spatial characteristics of the incremental threshold by using the two-color threshold method. The experimental results show that in the short- and long-wavelength ranges of the test stimulus, the color adaptation has dependency on the wavelength of the adaptive light, while, for the middle-wavelength stimulus, the it does not depend on the adaptation wavelength. It is not explained by the Stiles's π mechanism or a simple mutual interaction of the chromatic channel and the achromatic channels. Hence, the authors propose a five-stage model of the color adaptation which can explain the experimental results in a satisfactory manner.View full abstractDownload PDF (2556K) -
Masaki KOBAYASHI, Masashi USA, Humio INABA1994 Volume 30 Issue 4 Pages 385-391
Published: April 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSUltraweak photon emission originating from living systems and organisms is generally called biophoton emission and has known to occur naturally in conjunction with various vital processes of life. The aim of our study is to develop new techniques for biomedical measurements and analyses based on highly sensitive detection and characterization of biophoton emission from living samples of human origin. In this paper, we report the fundamental techniques and instrumentation developed newly for the measurement of ultraweak photon emission intensity and its spectral distribution together with basic characteristics of ultraweak photon emission from blood plasma, urine, sputum and breath samples taken from various subjects.View full abstractDownload PDF (1554K) -
Kazuyoshi KUBO, Nobuharu AOSHIMA1994 Volume 30 Issue 4 Pages 392-400
Published: April 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSStudy of analyzing methods of musical instrument tone decay is made. One of the method is spectrogram which is often used to analyze decay rate of musical instrument tone. And the other is reverberation decay curves which are often used to analyze decay characteristics of room reverberation. In this paper, the reverberation decay curves are considered to apply to musical instrument tone. The reverberation decay curves characterize energy held in the musical instrument while the spectrogram characterizes sound power of the instrument. If the sound output is given as analytic signal, the spectrogram indicates same gradient as the reverberation decay curve. But in general, same figure can't be indicated.
Three ideal systems are examined, including system containing single or multiple resonance, and system with resonance vibration which is started or stopped in the midst of time scope. It is shown that reverberation decay curves calculated using Wigner distributions are the most resemblant to expected figure among three known methods of reverberation calculation, because uneven component of overall curve and interference component of narrow band curve can be eliminated by the Wigner method. Still more, reverberation decay curves by the Wigner method are less influenced by window length than the spectrogram.
Reverberation decay curves, as well as spectrogram, are applied to musical instrument tones. Reverberation decay curves by the Wigner method can characterize the tone decay rate while the spectrogram is afflicted with interference. It is shown that piano tone decay can be characterized as two or four step decay figure in higher partial tone by the reverberation decay curves.View full abstractDownload PDF (1289K) -
Fumitaka KOGA, Ichiro SASADA, Koosuke HARADA1994 Volume 30 Issue 4 Pages 401-406
Published: April 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSMethods are presented by which the sensitivity of magnetic head type torque sensors can be maximized. The magnetic head type torque sensors employ an inductance bridge to detect the difference in self-inductances of a pair of magnetic heads faced to the shaft through an air gap. Parameters of the bridge circuit and a phase-sensitive-detector are optimized for a given pair of magnetic heads based on the phase diagram consideration. The methods are applied to the torque sensors using newly developed thin magnetic heads. Parameters predicted by the methods are confirmed to be well close to those obtained experimentally.View full abstractDownload PDF (1183K) -
Yasutaroh TANAKA1994 Volume 30 Issue 4 Pages 407-416
Published: April 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIt is necessary to identify the parameters of a controlled system for tuning control parameters. There are many studies on system identification for solving this problem. But, there are not many practical methods. Special test signals have often to be given to a controlled system for a long time in order to identify enough precizely to design the control system. This is not suitable for many actual systems.
In this paper, a simple method of system identification and tuning control parameters using ultimate oscillation like Zigler-Nichols method is mentioned. This is called α Parameter Method, and is based on the property of α parameter and λ parameter of a polynomial.
The relation between the frequency of ultimate oscillation and the coefficients of the partial term of the characteristic equation is formulated. The higher order coefficients of a polynomial are estimated from the lower order coefficients of it and the frequency of ultimate oscillation. In addition, the tuning method of I-PD control system using α parameter is mentioned.
α Parameter Method is compared with Zigler-Nichols method, and the usefulness for various controlled systems are showed by simulations.View full abstractDownload PDF (1632K) -
Shiro MASUDA, Akira INOUE, Valeri T. KROUMOV, Kenji SUGIMOTO1994 Volume 30 Issue 4 Pages 417-426
Published: April 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper a new structure of model reference adaptive control system which includes a fixed compensator is proposed. A continuous-time, single-input single-output control system is considered. The structure is derived by using coprime factorization approach in the set of proper stable rational transfer functions. The boundedness of all signals in the closed-loop system and the convergence of the output error is proved. The main feature of the proposed method is that the fixed compensator function is chosen independently of specifications with respect to responses for reference commands. It is shown, also, that through a proper selection of the fixed compensator a model reference adaptive control system which cancels exactly the effects of deterministic disturbances can be constructed. By means of a simulation example the effectiveness and applicability of the proposed method is proved.View full abstractDownload PDF (1818K) -
Mitsuji SAMPEI, Tadaharu KOBAYASHI1994 Volume 30 Issue 4 Pages 427-434
Published: April 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn our previous works, we designed a path tracking controller for articulated lorry type vehicles. We showed that we can design path tracking controller using input/state linearization technique, if the joint of the tractor and the trailer is located at the middle point of tractor's rear wheels. However, this assumption is not always satisfied, for example, the joint of a car-caravan type articulated vehicle is not located at the middle point of tractor's rear wheels. If it is not satisfied, we cannot use input/state linearization technique. In this paper, we propose path tracking controller for car-caravan type articulated vehicle using partial linearization technique and time scale transformation. We will show, in the simulation and the experiment, that the proposed controller works satisfactorily, and the car-caravan type articulated vehicle follows the desired path when it is moving forward and/or backward.View full abstractDownload PDF (2098K) -
An Efficient Computation Method of Model-Based Adaptive Control for Manipulators and Its ExperimentsHaruhisa KAWASAKI, Shinichi MOCHIZUKI, Kazuo KANZAKI1994 Volume 30 Issue 4 Pages 435-442
Published: April 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe model-based adaptive control of robot manipulators has been studied actively in recent years (e. g., Slotine and Li (1987), Sadegh and Horowitz (1987), Koditschek (1987), and Berghuies et al. (1992)). In these adaptive controllers, global asymptotic stability is guaranteed. But, it is difficult to apply them to manipulators with more than four degrees of freedom because of its computational complexity.
This paper presents an efficient computational algorithm of model-based adaptive control for manipulators. It adopts the basic method of Slotine and Li (1987) and uses the minimum parameter set of manipulator dynamic model, which was derived by Kawasaki and Kanzaki (1991). The number of operations in the algorithm is about one half of that presented by Niemeyer and Slotine (1988). This algorithm can be easily applied to the other model-based adaptive controllers with few modifications. We also present experimental results on the adaptive control of a robot manipulator with six degrees of freedom. Its control system has a 32 bit DSP for the computation of the adaptive control. The sampling time is 1.65ms.View full abstractDownload PDF (1477K) -
Robust stabilization via Nonlinear H∞ State FeedbackEiichi ONO, Shigeyuki HOSOE1994 Volume 30 Issue 4 Pages 443-451
Published: April 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe dynamics of an automotive vehicle are designed to be stable in the usual situation. However, when the driving condition changes from moderate cornering on a dry road to hard cornering on a low friction road, the dynamics sometimes indicate unstable characteristics and in the worst case the vehicle will fall into a spin.
The purpose of this study is to design front steering control system which protects from vehicle spin. By, numerical analysis, it is shown that the unstabilization is raised by a bifurcation depending on a rear tire force saturation. Depending this observation, the tire force perturbation, caused by changes of road environments, is modeled by feedback plant perturbations. Then, a controller which compensates the instability against the perturbations is designed by nonlinear H∞ control theory. Lastly, by computer simulations, the designed controller is shown to achieve robust stability and protect from vehicle spin.View full abstractDownload PDF (1321K) -
Kouichi MATSUDA, Kazuo NOSE, Takeshi YUZURIHARA1994 Volume 30 Issue 4 Pages 452-459
Published: April 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper discusses the solution method for a lot making problem. The developed system makes automatic lot making possible by using a constraint relaxation method for order specification and delivery time under the recent situation that are diversification of product types and decrease in order size. This constraint relaxation is realized by developing a rule interpretation function. This constraint relaxation method for lot making problem is useful in having the following functions.
(1) Setting of lot making constrains to meet management goals
(2) Ease of setting constrains for even non-experts in lot making
(3) Robustness to change of product types
Applying the system to the actual plant can reduce lot making time and improve delivery time.View full abstractDownload PDF (2664K) -
Toru TAZAWA, Noboru OHNISHI, Noboru SUGIE1994 Volume 30 Issue 4 Pages 460-466
Published: April 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSMany studies have been done on removal or suppression of reverberation. Among them, the approach, in which the impulse-response in a room is measured beforehand, has obtained very satisfactory results.
But an impulse-response is not invariant, and changes with time depending on the room temperature and humidity, and the relative location between a sound source and microphones. It is troublesome to measure an impulse-response exactly each time. So, we have tried to cancel echoes using only one signal with echoes, which is obtained through a single microphone.
In order to cancel echoes, we determine both delay time and amplitude ratio between direct wave and each of reflected waves. In the case that there are a few reflected waves, the result of simulation shows good recovery of an original sound.View full abstractDownload PDF (2221K) -
Tadashi EGAMI, Osamu TOYODA, Takeshi TSUCHIYA1994 Volume 30 Issue 4 Pages 467-469
Published: April 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSType-1 optimal preview servo system design method is proposed. Performance index of this system is essentially equal to that of optimal regulator system. In this control system design, order of augmented system can be reduced to that of original system.View full abstractDownload PDF (323K) -
Kazuya OGATA, Seizo FUJII1994 Volume 30 Issue 4 Pages 470-472
Published: April 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWhen a multirate model with a slow sampling rate for the output and a fast sampling rate for the input is identified, the estimated parameter usually increases in number. In this paper, a new approach is proposed to decrease in the number of the estimated parameter in the multirate model.View full abstractDownload PDF (354K) -
Tadashi EGAMI1994 Volume 30 Issue 4 Pages 473-475
Published: April 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDigital nonlinear preview control design method is proposed. This method is based on the principle that only acceleration changes at the moment when input torque changes. Linear optimal preview control system is designed on basis of this principle. It is applied to 3-link direct drive manipulator and its effectiveness is confirmed.View full abstractDownload PDF (366K) -
Yoshitomo OKADA, Kouji OBAYASHI, Thoru HOSOKAWA, Hao FENG, Kimio YAMAS ...1994 Volume 30 Issue 4 Pages 476-478
Published: April 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a improved method to determine the equivalent circuit parameters of single-phase induction motor. These parameters are determined by the measurement of primary winding resistance, locked-rotor test, no-load test at synchronous speed and DC braking torque test.View full abstractDownload PDF (344K) -
Yoshiaki HIMURA1994 Volume 30 Issue 4 Pages 479-481
Published: April 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSSeveral Neural Networks learning inverse dynamics are proposed to reduce control index. Comparison among them is also presented through the computer simulation. 23% reduction of index was attained when deviation and its first and second order derivatives are given as the teacher signals.View full abstractDownload PDF (358K) -
Takeshi FURUHASHI, Tomohiro YOSHIKAWA, Yoshiki UCHIKAWA1994 Volume 30 Issue 4 Pages 482-484
Published: April 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a method for maintaining diversity of chromosomes for solving the problem of premature convergence in genetic algorithms. With the new method, multiple phenotypes are produced from a chromosome and selections of the chromosomes are done with multiple fitness values. Diversity of the chromosomes are thus maintained and the premature convergence can be avoided.View full abstractDownload PDF (423K)
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