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Volume 36, Issue 5
Displaying 1-13 of 13 articles from this issue
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Yoshio KOSUGE, Shingo TSUJIMICHI2000 Volume 36 Issue 5 Pages 371-380
Published: May 31, 2000
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe problem of multiple-target tracking in the presence of extraneous measurements (i.e., clutter, thermal false alarms and other targets) and no reports (missed target detections) using the MHT (Multiple Hypothesis Tracking) or the JPDA (Joint Probabilistic Data Association) has received a lot of attention in recent years. The MHT requires a heavy computational burden. Therefore, an idea of clusters was introduced in the MHT. Clustering is a process of dividing a large problem in a wide region into independent small problems. A Track-Oriented MHT gives a significant improvement over the conventional method discussed in the original measurement-oriented MHT. Here, a track is defined by a time-series of at most one measurement data from each sample time. The M3 JPDA (Multiple Maneuver Model JPDA) is the extension and improvement of the conventional JPDA. Our computer simulation results showed that the M3 JPDA provides a definite improvement over the JPDA technique with regard to tracking success rates. In this paper, we have shown that the cluster in the Track-Oriented MHT is the finest clustering under the condition that any two tracks which have a common measurement must be in the same cluster. We propose a new technique, M3 Track-Oriented MHT, for maneuvering target tracking in a cluttered environment, using the track-oriented MHT. We can obtain suboptimal techniques in which M3 Track-Oriented MHT is equivalent to the M3 JPDA. This implies good maneuvering multi-target tracking maintenance capability of the M3 Track-Oriented.View full abstractDownload PDF (2192K) -
Hiroaki ISHIKAWA, Masaki TAKAMOTO, Kazuyoshi SHIMIZU, Hideaki MONJI, G ...2000 Volume 36 Issue 5 Pages 381-387
Published: May 31, 2000
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this study, the flow rate characteristics of ultrasonic flowmeters with variously shaped measurement sections or ducts and the flow characteristics in each measurement section were investigated experimentally and numerically. Also, the feasibility of flow rate measurements over a wide range, including the flow transition region, was investigated.
The experimental results reveal that the flow rate characteristics of the flowmeter were almost constant in regions of both laminar and turbulent flows in the case of a narrow rectangular duct connecting to a straight duct in the upstream side. Furthermore, the difference between the above case and the case of a narrow rectangular duct connecting to a bend in the upstream side was less than 1% in kh or the flow characteristics. Therefore, these results suggest that a narrow rectangular duct is highly suitable for an ultrasonic flowmeter.
The results of numerical simulation by an ultrasonic plane source verified that the flow rate characteristics of the ultrasonic flowmeter with a narrow rectangular duct were not influenced by the change in the velocity profile. That is, the flow rate characteristics of the ultrasonic flowmeter with a narrow rectangular duct were explained from the physical point of view not by an ultrasonic point source which considers the ultrasonic path between sensors to be as a single path or a line but by an ultrasonic plane source which considers the ultrasonic path to be as multipaths or a plane.
The linearity was within ±1.5% over a wide range of measurements. Thus, it is feasible that an ultrasonic flowmeter with a narrow rectangular measurement section can be put to practical use with such a high degree of accuracy.View full abstractDownload PDF (1960K) -
Koichi KAMEOKA, Makoto NAKATANI, Norio INUI2000 Volume 36 Issue 5 Pages 388-394
Published: May 31, 2000
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA certain type of weighing systems consisting of plural scales is referred to as a “combinatorial weigher”, with which the calculation in the combination of the measured values in carried out and a combination of the objects within a tolerance in mass value is produced. The combinatorial weigher dealt with in this paper consists of one scale for object-A and eight scales for object-B. In the combination process with the weigher, some unique phenomena in probability and statistics, so to speak, “synergy” can be found. By the aid of computer simulation, we examined the phenomena, comparing the “partial renewal case”, a combination method in question with the “whole renewal case”, a hypothetical combination method. And we also examined the “runs” in the combination processes. As the result, the properties and generating mechanism of the phenomena were clarified.View full abstractDownload PDF (2035K) -
Tohru IUCHI, Hirotaka ISHII2000 Volume 36 Issue 5 Pages 395-401
Published: May 31, 2000
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSRadiation thermometry of low emissivity metals near room temperature is very difficult because of the weak radiance from a target and the disturbance of abundant background radiation noise. Directional and polarized emissivities of glossy metals are studied theoretically and experimentally. The p-polarized emissivities of them are found to be quite high at the direction of more than 80°. On this basis, the principle of a simultaneously measuring method of emissivity and temperature is proposed. The experimental results of the method showed the temperature measurement was achieved within the error of ±3K at the laboratory. Considerations on the practical use of this method are mentioned and the limitations of the method are also discussed.View full abstractDownload PDF (3146K) -
Gan CHEN, Toshiharu SUGIE, Toru FUJINAKA, Hiroshi SHIBATA2000 Volume 36 Issue 5 Pages 402-408
Published: May 31, 2000
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper provides a new mixed-μ analysis method for dynamical systems without frequency sweep. First, we derive a necessary and sufficient condition for the closed loop system with dynamical system and real uncertainties to have μ less than a specified value γ by using descriptor form. Second, applying sector transformation and strictly positive real lemma to this result, we give a computable LMI condition for the mixed-μ analysis. Since our analysis can treat all uncertainties as time invariant, it may be less conservative than former ones including D-G scaling, Finally, an illustrative numerical example is given.View full abstractDownload PDF (1564K) -
Guisheng ZHAI, Kazunori YASUDA2000 Volume 36 Issue 5 Pages 409-415
Published: May 31, 2000
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, we study stability property for a class of switched systems composed of several subsystems, where each subsystem's vector field is composed of a linear time-invariant part and a nonlinear norm-bounded perturbation part. It is assumed that the linear subsystem matrices are commutative pairwise, and there exists a linear convex stable combination of unstable linear subsystem matrices. First, in the case of no perturbations, we propose a switching law under which the entire switched system is globally exponentially stable. In the switching law, Hurwitz stable subsystems (if exist) are activated arbitrarily while unstable ones are activated in sequence with their duration time periods satisfying a specified ratio. Secondly, under the same switching law, we analyze qualitative property of the switched system in the case where nonlinear norm-bounded perturbations exist. Some numerical examples are given in the paper to demonstrate the results.View full abstractDownload PDF (1403K) -
Toshiki OGUCHI, Atsushi WATANABE, Takayoshi NAKAMIZO2000 Volume 36 Issue 5 Pages 416-423
Published: May 31, 2000
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper single input nonlinear systems with non-commensurate time-delays in state variables are considered. The objective is to design a coordinates transformation and a feedback which yield a finite dimensional linear controllable closed-loop system in a new coordinates, whose spectrum is located at an arbitrarily preassigned set of n points in the complex plane. An algebraic design procedure for this problem is proposed here. The proposed method is related to the exact linearization technique for systems with a finite dimension, and recognized as the extension of the finite spectrum assignment of linear retarded systems. Effectiveness of the method is tested by illustrative examples.View full abstractDownload PDF (1776K) -
Yoshihiko MIYASATO2000 Volume 36 Issue 5 Pages 424-430
Published: May 31, 2000
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA design method of the new simple adaptive control systems is presented in this paper. In that adaptive scheme, the structure of overall control systems does not become so complex as relative degrees of controlled processes grow larger, and the stability conditions of error systems are explicitly reduced to the proper choices of two design parameters (one parameter should be sufficiently large, and the other should be sufficiently small). In the ideal case where no unstructured uncertainty exists, it is shown that overall systems are globally bounded and that the magnitude of output errors can be made arbitrary small by adjusting one of those two design parameters. Since adaptive laws of projection type are included in that method, semiglobal boundedness of overall systems is assured for small unstructured uncertainties.View full abstractDownload PDF (1133K) -
Masato KASAHARA, Tadahiko MATSUBA, Yoshiaki KUZUU, Takanori YAMAZAKI, ...2000 Volume 36 Issue 5 Pages 431-437
Published: May 31, 2000
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper concerns the development of a new design and tuning method for use with PID controllers that are commonly used to heating, ventilating and air-conditioning (HVAC) fields. The robust PID controller is designed for temperature control of a single-zone environmental space. Although the dynamics of environmental space are described by higher-order transfer functions, most HVAC plants are approximated by first-order lag plus deadtime systems. Its control performance is examined for this commonly approximated controlled plant. Since most HVAC plants are complex with nonlinearity, distributed parameters and multivariables, a single set of PID gains does not necessarily yield a satisfactory control performance. For this reason, the PID controller must be designed as a robust control system considering model uncertainty caused by changes in characteristics of the plant. The PID gains obtained by solving a two-disk type mixed sensitivity problem can be modified by contrast to those tuned by the traditional Ziegler-Nichols rule. The results, which are surprisingly simple, are given as linear functions of ratio of deadtime to time-constant for robustness. The numerical simulations and the experiments on a commercial sized test plant for air-conditioning suggest that the robust PID controller proposed in this paper is effective enough to practical applications.View full abstractDownload PDF (1645K) -
Satomi HATTORI, Muneaki ISHIDA, Takamasa HORI2000 Volume 36 Issue 5 Pages 438-447
Published: May 31, 2000
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSVariable speed drive systems of brushless DC motor have been widely used for industry applications, home electric appliances, and so on, due to the progress of the power electronics, because of simple structure, easy maintenance, high efficiency, etc.. However, structural imperfectness of brushless DC motor and its control system produce torque ripple, and cause mechanical vibration and torque ripple and acoustic noise.
In this paper, authors propose a suppression control method of vibration for brushless DC motor utilizing feedforward compensation control, and a generation method of compensating signals for the feedforward control by repetitive control with Fourier transform utilizing a vibration signal acquired by an acceleration sensor attached to the motor frame.
Because the vibration signals detected by the acceleration sensor contain various complicated frequency components due to motor torque vibrations and mechanical resonant vibrations around the motor load system, we can not stabilize the repetitive control system and reduce the vibration by directly using the vibration signals from sensor itself. So we propose a generation method of the compensating signals of the repetitive controller considering the periodicity of motor torque ripples, and using Fourier transformer which can select particular frequency components. In order to realize on-line generation of feedforward compensating signals to reduce the vibration, auto-tuning method of the repetitive control parameters is also presented.
An experimental system to detect and reduce the motor torque vibration is constructed, and the effectiveness of the proposed method is confirmed by experimental results.View full abstractDownload PDF (5685K) -
Koji MIYAZAKI, Hirotaka NAKAYAMA2000 Volume 36 Issue 5 Pages 448-455
Published: May 31, 2000
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIf computers and robots can feel glad or sad, and if they have emotion, human beings feel a sense of closeness to computers in communication with them. It has been observed thatt the facial expression is very important for the communication between people. A more friendly human interface may be realized by computers having the facial expression. As a part of this idea, in this paper, we propose a method for the expression synthesis by drawing caricatures. A neural network is applied for the recognition of facial expression. The characteristic quantities for drawing caricatures are calculated on the basis of the results of recognition. Accordingly, it seems to be able to draw more expressive caricature. Ekman states that basic facial expression are categorized into 6 groups, “happiness”, “surprise”, “anger”, “fear”, “disgust”, “sadness”. We deal with 6 categorized expressions as results of recognition. Computers draw a caricature by using the spline interpolation for the calculated characteristic points.View full abstractDownload PDF (3774K) -
Manabu KOTANI, Satoshi MAEKAWA, Seiichi OZAWA, Kenzo AKAZAWA2000 Volume 36 Issue 5 Pages 456-458
Published: May 31, 2000
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWe describe what characteristics an independent component analysis can extract from Japanese continuous speech. Speech data was selected from ATR database uttered by a female speaker. The data was recorded at 20kHz sampling frequency and was pre-processed with a whitening filter. The learning algorithm of a network was an information-maximization approach proposed by Bell and Sejnowski. After the learning, most of the basis functions that are columns of a mixing matrix were localized in both time and frequency. Furthermore, we confirmed that there were some basis functions to extract the acoustic feature such as the pitch and the formant of each vowel.View full abstractDownload PDF (504K) -
Yoshio TANAKA, Hiroaki MISAWA, Yohsuke KINOUCHI2000 Volume 36 Issue 5 Pages 459-461
Published: May 31, 2000
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, a new noncontact arrangement method for metal particles is proposed. The method forms optical cages by synchronous scanning laser beams, and arranges particles in the cages. This idea, which enlarges the ability of the laser scanning manipulation, is experimentally realized.View full abstractDownload PDF (2184K)
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