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Volume 28, Issue 1
Displaying 1-25 of 25 articles from this issue
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Takeshi HATSUZAWA, Takuma DOI, Kouji TOYODA1992 Volume 28 Issue 1 Pages 3-9
Published: January 31, 1992
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSTrial linewidth standards for the calibration of scanning electron microscopes (SEM's) used in semiconductor production have been manufactured and evaluated. A quantitive investgation of the relationship between peak-to-peak linewidth and cross sectional dimension has been made. The results show that the peak-to-peak values are 7nm smaller than the values obtained from cross sectional measurements. The edge signal peak shift has been simulated using a newly modified diffusion model and this also gives smaller linewidth than the defined edge distance. Linewidths measured optically have been compared with those measured by an SEM. The optical method gives wider linewidths by some dozens of nanometer. The influence of focusing errors and limit of the measurements have also been investigated.View full abstractDownload PDF (2757K) -
Shinji HARA, Manabu NAKAJIMA, Pierre T. KABAMBA1992 Volume 28 Issue 1 Pages 10-19
Published: January 31, 1992
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, the problem of robust stabilization is considered for sampled-data control systems, where the conitinuous-time plant with additive perturbation is robustly stabilized by a digital controller. First, sufficient conditions for the robust stability are derived using the small gain theorem. The conditions are given in terms of the L2-induced norm of a certain sampled-data system and its state-space form. Next, we develope a state-space condition for the robust stabilizability. The maximum uncertainty bound with respect to the sampling period can be computed by solving only two discrete-time Riccati equations. Finally, we investigate the properties of the maximum uncertainty bound, and it is shown that the maximum uncertainty bound tends to that for the continuous controller case as the sampling period goes to zero. The possibility for the improvement of the bound by changing the hold function is illustrated by simple examples.View full abstractDownload PDF (1410K) -
Seizo FUJII, Naoki MIZUNO, Narumi SUZUKI, Sachio KITAGUCHI1992 Volume 28 Issue 1 Pages 20-29
Published: January 31, 1992
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSAn adaptive control methodology using multiple identification models is presented. In the proposed method, the real process is identified simultaneously by multiple models with different structure and an adaptive control is carried out based on the optimum model selected by some rules. The selection rules of the suitable model for an operating condition are decided by theoretical and heuristic knowledge about the parameter estimation and adaptive control. This method requires few a priori information about the process and can deal with the abrupt change of the process characteristics. In this paper, first, the principle of the adaptive control system with multiple models is presented. Next, the main parts of the proposd system: model following control loop, recursive identifier with multiple models, model selecting function block and higher level adaptation mechanism are discussed. In order to investigate the effectiveness of the proposed method, computer simulations are carried out for processes with time-varying characteristics. Finally, the proposed method can be successfully applied to the temperature control of an incinerator.View full abstractDownload PDF (1875K) -
Osamu KATAI, Masaaki IDA, Tetsuo SAWARAGI, Sosuke IWAI1992 Volume 28 Issue 1 Pages 30-39
Published: January 31, 1992
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSFor solving large complex problems, it is essential to construct problem solving methods which incorporate the human ability to cope with fuzziness. This paper proposes a new method of representing and treating“fuzziness”, by noting that fuzziness can be reduced to a coherent structure to the order constraints involved in the object space (universe of discourse). Seen from this perspective, fuzzy inference can be regarded as a kind of constraint propagation. Furthermore, the new methods of fuzzy set operations and defuzzification introduced are effectively utilized for problem solving. Through them, symbolic (hard) inference is related to fuzzy (soft) inference on the same ground, in such a manner that the qualitative part of fuzziness, its“type”, is set at the initial stage of problem solving, and the quantitative part of fuzziness, its“shape”, is progressively set in accordance with the advances in problem solving, thus resulting in a “distributed network system structure”of fuzziness.View full abstractDownload PDF (2723K) -
Masaaki MURATA, Masatoshi HARIGAE1992 Volume 28 Issue 1 Pages 40-49
Published: January 31, 1992
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSSelective Availability (SA) was turned on between the period of March 25 to August 28, 1990. SA is aimed to degrade positioning accuracy of civilian GPS users by adding intentional errors into the broadcast ephemerides and satellite clocks in the GPS navigation message, and it is believed to be implemented in the full operational phase of GPS (about mid-1993).
In order to estimate the magnitude, time behavior, dynamical and statistical characteristics of SA errors, the pseudorange and delta-pseudorange observations were taken during the above period using a C/A code, single channel GPS receiver NAVCORE-1 of National Aerospace Laboratory (NAL). And SA errors were analyzed by computing residuals for both pseudorange and delta-pseudorange data.
Analysis results show that: (1) SA was implemented on the Block-II satellites only. (2) SA errors in the pseudorange data consisted of both short periodic components with the period of a few minutes and long periodic terms with the period of a few hours, the magnitude ranging from 30-50m (RMS), which is consistent with the stated policy of U. S. Department of Defense (DoD). (3) For the Block-II satellites the anomalous residuals in the delta-pseudorange data were also observed, but the magnitudes of which were below the formal standard deviation of the receiver error and thus the effect on navigation accuracy in velocity can be ignored.View full abstractDownload PDF (1939K) -
Masao IKEDA, Toshiro ONO, Nobuo AOKI1992 Volume 28 Issue 1 Pages 50-58
Published: January 31, 1992
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDynamic mass measurement for moving vehicles is proposed utilizing linear system theory. The measurement system considered in this paper is a vehicle scale commonly used for static measurement. In case a vehicle does not stop on the platform, the measured signal cannot be expected to be constant, but contains disturbance signals caused by the dynamics of the measurement system and the vehicle to be measured. Then, we have to eliminate the disturbance signals in order to extract a constant signal propotional to the mass of the vehicle.
The difficulty in this problem is that we have no sufficient prior information about the dynamics of the vehicle. Therefore, we need to identify it after we start measurement. For this purpose, the linear system theory is an appropriate tool. We present a method of computing parameters representing the dynamics of the vehicle from the measured signal. In this way, the mass of the vehicle can be calculated. Experimental results imply that the precision of 1/1500 can be achieved.View full abstractDownload PDF (1666K) -
Yasuyuki FUNAHASHI, Manabu YAMADA1992 Volume 28 Issue 1 Pages 59-66
Published: January 31, 1992
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn the tracking control problems, e. g. robotic arms, tracking performance with high speed and high accuracy has been required. The feedforward controller by which the controlled output is driven to the desired one with no error may cause undesirable pole/zero cancellation.
To avoid undesirable pole/zero cancellation, the feedfoward controller based on phase cancellation has been proposed. The phase cancellation implies that the overall frequency response exhibits zero phase shift for all the frequencies. This is termed Zero Phase Error Tracking Controller (ZPETC) and is a discrete-time preview controller.
This paper presents a general form of ZPETC and the explicit parametrization. The contributions are as follows: (1) The synthesis of ZPETC with minimum preview steps which makes the gain of the overall controlled system equal to unit at zero frequency is presented. The controlled output is driven to a step and ramp desired one in a finite steps. (2) The synthesis of ZPETC by which the controlled output is driven in a finite steps to the desired output consisting of a time polynomial is presented.View full abstractDownload PDF (1420K) -
Zheng-Hua LUO1992 Volume 28 Issue 1 Pages 67-76
Published: January 31, 1992
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents new theoretical and experimental results on control of flexible robot arms using direct strain feedback method. First, a class of perturbation operators satisfying some assumptions is defined, then the properties of the perturbation operators themselves and the issues such as the existence, uniqueness, and stability of a second order evolution equation involving the perturbation operator are investigated. It is found that the direct strain feedback defines a differential perturbation operator and introduces damping in the dynamic model of the flexible arms.
To verify these theoretical views, experiments such as direct strain feedback, direct strain-integration feedback were conducted. It is seen that the direct strain feedback can damp out vibrations quite satisfactorily, and that the direct strain-integration feedback increases the vibration frequencies of every modes of the flexible arms. For the case where the flexible arm carries a rigid tip body, it is shown that the coupled bending and torsional vibrations of the flexible arm can be suppressed simultaneously by direct feedback of both the bending and torsional strain signals.View full abstractDownload PDF (2326K) -
Tomomichi HAGIWARA, Yoshihiro OHTANI, Mituhiko ARAKI1992 Volume 28 Issue 1 Pages 77-86
Published: January 31, 1992
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper studies a method for designing a robust servo system in which the plant variables (i.e., plant input and plant output/state) converge to their steady-state in an optimal fashion with respect to the usual regulator-type quadratic-integral performance index. Since the performance index does not weight the compensator state, the optimality attained by the resulting control system has a definite significance that it achieves quick tracking of the plant output/state while suppressing a large peak in the plant input. Also, the steady-state error compensation involved in the resulting control system has a desirable feature that it actually works only when there exist some disturbances and/or modeling error of the plant. Accordingly, this design method provides us with two-degree-of-freedom approach, in which we can tune feedback characteristics such as disturbance attenuation and robust stability without changing the responses of the plant input and plant output/state for the reference input at all.View full abstractDownload PDF (2090K) -
Tohru KATAYAMA, Yoshikazu ONUKI1992 Volume 28 Issue 1 Pages 87-96
Published: January 31, 1992
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper considers an infinite-horizon linear quadratic regulator problem and a related spectral factorization for constant discrete-time descriptor systems. We derive a descriptor Riccati equation (DRE) and the optimal feedback gain using a generalized Lyapunov equation. By applying a compact notation for descriptor transfer matrices, we also present a new spectral factorization algorithm that is valid even if the A-matrix is singular and/or the D-matrix is not of full column rank for the state-space model. Moreover, based on the solutions of (generalized) eigenvalue problems associated with the Hamiltonian equation, we develop a non-recursive method for obtaining the admissible solution of the DRE and the optimal feedback gain. A numerical result is also included.View full abstractDownload PDF (1419K) -
Takashi SUZUKI, Hiromitsu SUZUKI, Hiroshi SATOH1992 Volume 28 Issue 1 Pages 97-106
Published: January 31, 1992
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIt is necessary for practical applications to design the adaptive control system which behaves robustly in the presence of unmodeled dynamics such as parasitics. This paper presents a design method of the indirect model reference adaptive control system robust to the presence of parasitics. In this method, the plant parameters are estimated by an adaptive law with relative dead zone and then the controller parameters are determined by calculation using the current plant parameter estimates. The output error between the plant and the reference model, arising from the use of dead zone in the adaptive law, is reduced by employing a fixed feedback compensator. The stability of the overall system is analyzed using both the singular perturbation theory and the Liapunov's direct method, and it is then shown that the adaptive control system is able to behave robustly in the presence of parasitics if the size of dead zone is specified appropriately.View full abstractDownload PDF (1635K) -
Application of LQ Loop-Shaping CapabilityTakashi KIDA, Isao YAMAGUCHI, Masao IKEDA1992 Volume 28 Issue 1 Pages 107-115
Published: January 31, 1992
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper studies the LQ regulator loop shaping capability in order to enhance the LSS stability robustness, experimentally. To this end, a frequency-dependent optimal regulator gain is designed to give the low-pass property to the loop transfer function in a LQ framework. Then a state estimator is constructed to preserve its property in a Loop Transfer Recovery manner. A ground-based experiment is performed by utilizing a single-axis air-table.View full abstractDownload PDF (2203K) -
Hisao ISHIBUCHI, Hideo TANAKA1992 Volume 28 Issue 1 Pages 116-124
Published: January 31, 1992
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWhen we attempt to model a complex system including human as an important component, it may be difficult to represent the system by a deterministic mathematical model. The main reason of this difficulty is that the system itself inherently has some fuzziness concerning subjective judgement of human. As a promising modelling method to cope with this difficulty, the concept of fuzzy regression was proposed and various methods were developed. In this paper, we propose a fuzzy regression method using multilayer neural networks. Since multilayer neural networks have high capability as an approximate realization tool of nonlinear mappings, the proposed method has higher flexibility than fuzzy linear regression models. First we propose learning algorithms to identify a nonlinear interval model which approximately includes all the given input-output data. Next we propose methods to derive a fuzzy model from the identified interval model. Last the proposed method is applied to a quality evaluation problem of injection moldings. The fuzzy relation between subjective ratings of the quality given by experts and gap depths of weld-lines is analyzed using the proposed method and its modelling ability is demonstrated.View full abstractDownload PDF (1637K) -
Ken TANAKA, Masayuki YAMAMURA, Shigenobu KOBAYASHI1992 Volume 28 Issue 1 Pages 125-134
Published: January 31, 1992
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWe know the fact that multi-layered neural-network seem to perform some kind of information processing through the pattern-translation, but have not known the actual form of processing up to date. This brings us the difficulty to evaluate objectively the acquired structure and the effect of the learning. In this paper, we regard the internal process of the neural network as extracting the logical relations from the input patterns. First, we propose a generalized multi-layered neural-network which includes the higher-order connections. After formulating the neural network in a general form, the extended Back-Propagation learning algorithm is derived. Secondly, we present a theorem that the network model can realize all of the logical function within any value of mean squared error. We confirm the meanings of the theorem through the computer simulation about the 4-bits odd parity problem. Finally, we show the result of application to some typical examples. The simulation of XOR problem, which is one of the most general methods to evaluate the ability of a network, shows that if the network has the suitable structure to acquire the conjunctive relation of the input pattern, we can accelerate the convergence of learning. The simulation of the Encoder problem show that if the structure of the network is not suitable for the problem, the effect of acceleration is not appeared. Through these experimentations, we can make sure that the proposed model can make the internal function clear and improve the network performance remarkably.View full abstractDownload PDF (2366K) -
Wataru MITSUHASHI, Kazuyuki OHMURA1992 Volume 28 Issue 1 Pages 135-143
Published: January 31, 1992
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIt is still a difficult problem for machine vision systems to obtain range information, while animals can easily perceive the distance around their environment. Thus learning the functions of biological visual system is essential for the implementation of efficient machine vision systems.
According to E. L. Schwartz, the authors constructed a mock architecture of ocular dominance columns in the visual cortex, by implementing a column-like image with interlaced scan lines taken alternately from left and right cameras. The areas which have horizontal disparities can be extracted by bandpass filtering the column-like image, and hence we can formulate disparity estimation as a problem to minimize the output energy of the band pass filter.
This paper describes derivation of a new algorithm for disparity estimation and presents experimental results which demonstrate the ability of the algorithm to recognize three dimensional environmental structures. It is also shown that this algorithm has the same principle as the profile recovery system using a differential identity of binocular stereo, proposed by S. Ando.View full abstractDownload PDF (2838K) -
Keisuke KINOSHITA, Koichiro DEGUCHI1992 Volume 28 Issue 1 Pages 144-153
Published: January 31, 1992
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSRecently, many active vision techniques for object recognition are reported in the literatures. In the technique, the shape of an object is reconstucted using the motion parameters of the camera and the image optical flows of the object points. However, obviously, the motion parameters must be measured exactly for the 3-D shape reconstruction. In usual cases, it is difficult to know such exact motion parameters by using the sensors attached to the camera. But, the image pixels taken from the camera have much more accurate capability to locate the point positions than those sensor's outputs.
In this paper, we propose a new method of active vision which can recognize the 3-D shape of an object without knowing exact camera motion parameters. The motion parameters are calculated from the optical flows and the depth of object points whose 3-D shape is already known. And, using this calculated motion parameters and the optical flows, the 3-D position of unknown points are reconstructed. Repeating these two phases, taking the image of a known object, 3-D shape of unknown objects are reconstructed as camera moves. In this method, only the sequence of images are used to determine the camera motion and the 3-D point positions.
In this method, the effects of quantization errors, which cannot be avoided in digital image analysis, will be overcome by two approaches. As for camera motion parameters, the errors are compensated by using a large number of points to calculate the position and the velocity of the camera. Then, the Kalman filtering method is applied to the sequence of images to reduce the 3-D position errors of each unknown points.
Results of experimental simulations are shown to confirm the effectiveness of this proposed method.View full abstractDownload PDF (2233K) -
Mitsunori IKEGUCHI, Takahiro ISHII, Junta DOI1992 Volume 28 Issue 1 Pages 154-155
Published: January 31, 1992
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA bio-molecular backbone is displayed using splines with arbitrary shapes of the section. An iso-value surface of a bio-molecular property is developed to form a solid-model, representing total 5 dimensional parameters (x, y, z, iso-value surface, color), and is applied to visualize the bio-molecular activity.View full abstractDownload PDF (808K) -
Hiroyasu ITOH, Masahiro HIBINO, Masaya SHIGEMORI, Musubu KOISHI, Akira ...1992 Volume 28 Issue 1 Pages 156-157
Published: January 31, 1992
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWe describe a novel microscope system which allows us to capture fast cellular phenomena as sequential images. Several deformation patterns and the formation of a large hole(s) in the lipid membrane have been first visualized as μsec sequential images.View full abstractDownload PDF (545K) -
Takayuki SAKAGUCHI1992 Volume 28 Issue 1 Pages 158-159
Published: January 31, 1992
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSAlternative collinear laser beams trapping of Latex particles and bacterium are demonstrated with a close view and a microscopic view. Virtical trapping force are estimated as 1∼100nN/W to measure the flow in the sample cell with a microscopic view.View full abstractDownload PDF (513K) -
Takao AKATSUKA, Tohru TAKEDA, Yasutaka TAMURA1992 Volume 28 Issue 1 Pages 160-161
Published: January 31, 1992
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSTo understand a 3D object from images, verious observations and/or apriori knowledge is very useful. This paper demonstrates the integration of 3D displays of such multi-observed data by superimposing myocardium images from scintigrams and anatomical coronary arterial models (or coronary arteriogram images in the same patient).View full abstractDownload PDF (687K) -
Sadatoshi MIURA1992 Volume 28 Issue 1 Pages 162-163
Published: January 31, 1992
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSRadiography by photoemission (“emissiography”) was used to study the 12∼13th century wall painting at Byodo-in temple. The results brought important art-historical information about the technique and pigments used for the painting.View full abstractDownload PDF (860K) -
Fumio KOBAYASHI, Takashi NOMURA, Kazuo YOSHIKAWA, Hatsuzo TASHIRO, Mas ...1992 Volume 28 Issue 1 Pages 164-165
Published: January 31, 1992
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA proposed measurement is based on a zone-plate interferometry and secure a considerably high degree of stability for fringes even with the vibration of the machine or the disturbance of the air. The experiment shows that the zone-plate interferometer is suitable for on-machine profile measurement.View full abstractDownload PDF (904K) -
Yukio HIRANAKA, Hiro YAMASAKI1992 Volume 28 Issue 1 Pages 166-167
Published: January 31, 1992
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA sensor array is a universal means of visualizing fields of physical quantities. The method briefly described here can be applied to visualize any kind of field including non-physical quantity fields. The method's ability is demonstrated in the cases of sound and gas/smell fields.View full abstractDownload PDF (837K) -
Hiroshi HANAIZUMI, Hiroshi OKUMURA, Hiroe TSUBAKI, Sadao FUJIMURA1992 Volume 28 Issue 1 Pages 168-169
Published: January 31, 1992
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSAn automatic method is proposed for registration between a pair of remotely sensed images. This method has hierarchial structure and uses triangle division technique. New control point pairs for division are automatically generated. The validity of the method is confirmed by numerical simulation.View full abstractDownload PDF (812K) -
Kazuyoshi ITOH, Takashi INOUE, Yoshiki ICHIOKA1992 Volume 28 Issue 1 Pages 170-171
Published: January 31, 1992
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA fast technique for the segmentation of multispectral images that have spectral resolutions as high as their spatial resolutions is demonstrated. The technique deals with transform-coded data so that the computing time for decoding and processing is significantly reduced.View full abstractDownload PDF (758K)
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