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Volume 29, Issue 2
Displaying 1-19 of 19 articles from this issue
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Shinji OHYAMA, Yoshiaki TANAKA, Akira KOBAYASHI1993 Volume 29 Issue 2 Pages 125-132
Published: February 28, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper describes about the measuring system by using the signal field, which makes positive use of so called active sensing method, in particular about composing method of enclosing signal field and its application.
First, we proposed the method for composing optical enclosing signal field by linear LEDs, and considered the property of this field. It was found that its equiphase lines look like latticework, and that this is suitable for two dimensional position measurement. Next, we considered its application for position and attitude measurement on a plane. Furthermore, we presented practical flushing function realized by simple electric circuits and gave signal processing procedures. Taking above things into consideration, the experimental measuring system is composed. The experimental reasults are as follows.
(1) The range of position measurement is |x|, |y|≤50mm, and error is within ±2mm.
(2) The range of attitude measurement is |θ|≤25 degrees, and error is within ±3 degrees.
This study aims at application for automatically guided vehicles in factories and construction works.View full abstractDownload PDF (2038K) -
Takeshi HATSUZAWA, Yoshihisa TANIMURA1993 Volume 29 Issue 2 Pages 133-136
Published: February 28, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe secondary electron signals of scanning electron microscopes (SEMs) are widely used in electron beam measurement systems in IC factories, since they reflect step-edge information of minute patterns. A theoretical approach to define the relationship of actual pattern edges and peaks of the secondary electron signal is necessary because of the difficulty of experimental determination.
Currently, a modified diffusion model is employed to predict the secondary electron signal distribution at edges; however, its direct application for steep edges presents some problems. A cylindrical projection model is therefore proposed for both steep and gentle edges, in which the secondary electron emission area is defined by the surface included by a cylinder rather than the spheroids of conventional models.
To establish the validity of the model, micro-edges were fabricated on silicon chips, and then evaluated by a metrological scanning electron microscope. Comparison of experimental and simulated results confirmed that the model predicted both peak position and edge gradient difference with good accuracy.View full abstractDownload PDF (1719K) -
Admittance Measurement of Semiconductor Gas Sensor for ImprovementTakashi MORI, Hiro YAMASAKI1993 Volume 29 Issue 2 Pages 137-143
Published: February 28, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn the sensor fusion system using multiple sensors, space difference between each sensors often cause contradiction of data. The method of multiple parameter detection from a sensor avoids the contradiction. In this paper, feasibility of the method is studied as multiple parameter detection from a semiconductor gas sensor.
Output of gas sensor is influenced by temperature and humidity. Ambient temperature variation is compensated using separate temperature sensor at present. Surface temperature of the sensor device is kept hot for quick response. Cooling due to wind can change the heated surface temperature. We propose a method of temperature detection of sensor device by measuring admittance of the gas sensor.
Simple physical model is presented which describes conductance vs. capacitance characteristics, and it is proven by experimental, results. Calibration for temperature compensation can be simplified by this model. Disagreements with experimental results are discussed, and experimental phenomenon on frequency dependency and nonlinearity of capacitance both agreed with theoretical phenomenon qualitatively.
The mobility of the sensor depends on not reducing gas but humidity. Humidity can be sensed by utilizing the model, if the temperature is known.View full abstractDownload PDF (1964K) -
Shigeru TANISAWA, Haruo HIROSE, Nobuyuki YOSHIHISA1993 Volume 29 Issue 2 Pages 144-151
Published: February 28, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe sound detection method flowmeter is known to be easily affected by external noises, since received signals are extremely small. Therefore, its accuracy and reproducibility have been sometimes problems although the total instrument is very simple.
We planned to improve its performance by utilizing the bursting sound of air bubbles generated by obstacle built in a pipe (we call this method as active sound detection method).
For the improvement of performance and the reduction of influence by alien noises, we used two sensors at upstream and downstream of the obstacle, and both received signals were averaged respectively and then the difference of each signal was obtained for the differential operation by the amplifier in the received system.
For the performance test, the experiments on both received signal of the active sound detection method and flow rate of a turbine meter were performed by changing obstacles, measurement positions and temperature of the fluid. After that, we practiced regression analysis of them, and errors, regularity and proportionality were investigated. Consequently, we can lead to the following conclusions.
1) The active sound detection method was improved considerably and will be as usable as the conventional sound detection method to some extent.
2) The measurement errors in reference with a turbine meter were less than 1% at such obstacles as square pole, sigma pole and circular cylinder, with a cubic empirical formula.
3) The accuracy was nearly independent of the diameter of measuring pipe.
4) The regularity of average received voltage at various measuring unit positions of our experimental system was about 1∼2%.
5) The regularity of average received voltage to the fluid temperature change was about 2∼3% around room temperature.
As mentioned above, the active sound detection method possibly gives a practical flowmeter.View full abstractDownload PDF (1743K) -
Masanori IDESAWA, Huai-Dong DING1993 Volume 29 Issue 2 Pages 152-158
Published: February 28, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA new type of semiconductor position sensitive device called R-HPSD (Riken Hybrid Type Position Sensitive Device) has been invented. The relative resolution of image position sensing can be increased more than several ten times higher than that of conventional type PSD even though using the conventional circuit technology and without any serious sacrifice in simplicity of instrumentation and detecting speed. In addition, the image position detecting resolution can be changed adaptively by selecting suitable output terminal pair. Then the rough detection in wide range and precise detection in narrower range can be realized very easily with the same detecting element. Several prototypes have been manufactured based on the R-HPSD scheme and multi-resolution sensing capability has been proved by measuring image position sensing characteristics of them. This multi-resolution sensing capability is expected to apply for realizing new types of sensing system required in automation system such as robotics. For instance, it is expected to be used as a sensing element for introducing hierarchial sensing mode such as monitoring mode and attentive or intentional sensing mode.View full abstractDownload PDF (1275K) -
A Generalized Design Method Based on Parallel Feedforward CompensatorIkurou MIZUMOTO, Zenta IWAI1993 Volume 29 Issue 2 Pages 159-168
Published: February 28, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSSimple adaptive control (SAC) method is fundamentally applicable to the plants which satisfy the so-called almost strictly positive real (ASPR) condition. This condition is not satisfied by most of actual plants. However, as being indicated by several researchers, the non-ASPR plant can be made ASPR approximately by implementing a parallel feedforward compensator to the plant. For SISO systems, a practical design method for SAC systems with parallel feedforward compensator has been proposed and high control performance has been obtained. In this paper, we deal with a problem concerning actual realization of MIMO SAC system. A practical design procedure of parallel feedforward compensator, which makes non-ASPR MIMO plant into ASPR approximately, is considered so that practical realization of MIMO SAC is attained for broad class of MIMO plant. The effectiveness of the proposed method is confirmed through numerical simulations for the 2-inputs 2-outputs systems.View full abstractDownload PDF (1440K) -
Feifei ZHANG, Shigeyuki HOSOE1993 Volume 29 Issue 2 Pages 169-178
Published: February 28, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper treats the non-standard two-blocks H∞ control problem where the number of measurable outputs is not less than that of the exogenous inputs. The problem corresponds to the case where part of the system states are directly observed without measurement noise. The solvability conditions and the parameterization of the controllers to the problem are derived. It is shown that the order of the controllers can be reduced to the order of the least-order observer. As a useful application of the result, the synthesis of robust servomechanism is given.View full abstractDownload PDF (1438K) -
Hiroyuki TSUJI, Akira SANO1993 Volume 29 Issue 2 Pages 179-187
Published: February 28, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSSmall sampling period is preferable in system identification. However, the LS estimate of an impulse response tends to have a large mean squares error (MSE) when input-output signals are sampled at too fast rate. In this paper, we decimate the input-output signals which are sampled at fast rate to improve the condition number of the input correlation matrix and then calculate the decimated LS estimate, which then should be interpolated at fast original sampling rate so as to derivate the MSE of the impulse response estimate. A MSE criterion is given in terms of the decimation rate, which depends on a power spectral density of input signals, a frequency response of the system, a noise variance, and data length. Thus it is clarified there exists an optimal decimation rate which minimizes the MSE. We also clarify that an optimal decimation rate can be obtained by using the only input-output data.View full abstractDownload PDF (1517K) -
Kazuya OGATA, Seizo FUJII, Yoshikazu HAYAKAWA1993 Volume 29 Issue 2 Pages 188-193
Published: February 28, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe discrete-time Generalized Predictive Control (GPC) method has been developed in recent years. The continuous time version of GPC has been proposed by Gawthrop and co-workers. This is called Continuous-time Generalized Predictive Control (CGPC). The CGPC has very similar features to GPC. It can easily handle complex systems, such as at the same time open-loop unstable, non-minimum phase and higher order.
In the case when a system is described in continuous time domain, the parameters of the plant's model to be estimated usually have physical meanings. Therefore, the known physical parameters need not be estimated. This is very useful as compared with a discrete time adaptive control.
In this paper, we extend CGPC proposed by Gawthrop to MIMO system. First, a new algorithm of calculating the prediction of the plant output derivatives is proposed, in which the plant description is transformed into nonminimal expression using the signal through the adequate filter and recursive algorithm is introduced to make the prediction of the plant output derivatives. Using this recursive algorithm, the computation can be simplified. Next, the way of getting the good tracking performance is proposed using future setpoints when they can be used in advance. Finally, we show some simulation results to verify the effectiveness in the proposal method.View full abstractDownload PDF (743K) -
Yasuo TAKAGI, Toshiaki SOGABE, Kaiichiro HIRAYAMA, Takashi SHIGEMASA1993 Volume 29 Issue 2 Pages 194-200
Published: February 28, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA power system stabilizer which stabilizes power oscillations in wider system conditions is proposed. To this purpose, a new state-space linearization methodology is developed which belongs to geometrical nonlinear control theory. Furthermore, the linearization yields linear system that is the first order approximation of the nonlinear system, and nonliear compensator for exact linearization. The feature brings robustness against unmodeled dynamics at least around the origin. Then heuristic approximations are introduced to widen the exactly linearizable class.
The design method is applied for single-machine infinite bus power system. Then a power system stabilizer is obtained which stabilizes power system of wider conditions, such as angular positions and system impedances. Adding a system observer, the ability is proved by computer simulations of single-machine infinite bus system and multimachine system.View full abstractDownload PDF (1495K) -
Taro MAEDA, Susumu TACHI1993 Volume 29 Issue 2 Pages 201-210
Published: February 28, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIt is known in psychology that the human visual space and kinesthetic space do not completely coincide. Human subject's response undershoots the hand reaching point in depth under the visual control of reaching movement without vision of his limb. In this paper, six neural network models of sensory integration of binocular view space and kinesthetic space using hand position are presented to find how the joint angles of the right arm and eye movements are integrated into the human space perception. Visual reaching experiments revealed that one of the presented models showed a characteristics which was similar to those of the human subjects. The structure of the model is equivalent to the structure of human sensory integration. In this sensory integration, the signal space for the perception of the positional coincidence is that of the arm joint angles. The signals of eye movements are transformed into the equivalent signals of the arm joint angles which are similar to the signals for the arm control. It suggests that such a structure is organized for the needs of the arm control in this type of sensory motion control.View full abstractDownload PDF (2194K) -
Nobuo SANNOMIYA, Akira SHIMADA, Hiroshi NAKAMINE1993 Volume 29 Issue 2 Pages 211-219
Published: February 28, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe autonomous decentralized system is a system whose functional order is generated only by cooperative interactions among its subsystems. In other words, the system does not have any supervisor for the entire system. Instead, each subsystem has the autonomy to control each part of the system. But, that system has not been realized yet as an artificial. Fortunately, there are many examples of the autonomous decentralized system in the biological and ecological world. In this paper, we consider a fish school as an autonomous decentralized system. The schooling mechanism of a fish behavior is studied by using modeling and simulation techniques.
A water tank experiment was carried out to obtain an observation data for fish behavior and to know a special feature of a school. The unknown parameters included in the model were estimated by using a water tank experiment data. The relationship between the information obtained by each individual and the state of school was investigated.View full abstractDownload PDF (1519K) -
Kiyoharu TAGAWA, Yuzo OHTA, Mashakazu FUJIWARA, Hiromasa HANEDA1993 Volume 29 Issue 2 Pages 220-226
Published: February 28, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, an optimization problem to reduce the number of operations in computing the inverse dynamics of robotic manipulators: when the symbolically derived dynamic equation is given, we transform the equation into a set of statements which reduces the computing time. We propose an optimization algorithm to remove redundant computations from the symbolic equation generated by an algebraic computation system like REDUCE. The goal of the algorithm is to put the symbolic equation in the simplest possible form of computation. Using the algorithm, we develop the optimizer coded by C++. Usually, the symbolically derived dynamic equations consists of hundred terms. Then, in order to effectively use the memory space, we propose the hierarchic multilist data-structure to represent and manipulate the equations. The optimizer is applicable to optimize any type of symbolic equations represented by sum of products. To demonstrate the usefulness of the optimizer, we show some examples treating Lagrange equations for robotic manipulators.View full abstractDownload PDF (1320K) -
Kajiro WATANABE, Satoru SUZUKI1993 Volume 29 Issue 2 Pages 227-229
Published: February 28, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper describes a method to measure the material volume in a tank by using the Helmholtz resonance frequency. The method improves the accuracy by using the harmonics of the Helmholtz resonance frequency.View full abstractDownload PDF (263K) -
Akihiko MATSUSHITA, Takeshi TSUCHIYA1993 Volume 29 Issue 2 Pages 230-232
Published: February 28, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper shows that optimal preview control system approaches a decoupled preview control system as weighting matrix for input variables in quadratic performance index tends to zero. By this property, relation between design parameters and responses of optimal preview control system becomes approximately apparent.View full abstractDownload PDF (352K) -
Tsutomu NAGADO, Etsujiro SHIMEMURA, Tsutomu ISHIDA, Kenkou UCHIDA1993 Volume 29 Issue 2 Pages 233-235
Published: February 28, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper introduces a controller reduction method which considers preserving closed-loop properties. We regarded the reduction problem as a frequency weighted approximation problem and derived the weightings for maintaining the properties.View full abstractDownload PDF (309K) -
Koichi SUYAMA1993 Volume 29 Issue 2 Pages 236-238
Published: February 28, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a design method of PID control systems for a class of plant models with time-delay. It only needs simple calculation and can achieve adequate step responses.View full abstractDownload PDF (325K) -
Zhi-Wei LUO, Hideki TAKAHASHI, Masami ITO1993 Volume 29 Issue 2 Pages 239-241
Published: February 28, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper studies on robustness problem of robot performing compliant manipulation on dynamic environment when there exit model errors on robot's dynamics. By modifing the robot's model errors as a kind of transfer function on frequency domein, we show that if we select the reference model following the reference model's design criteria which was proposed in another paper of authors, the model matching control structure will also be very robust to robot's model errors.View full abstractDownload PDF (399K) -
Akihiko MATSUSHITA, Takeshi TSUCHIYA1993 Volume 29 Issue 2 Pages 242-244
Published: February 28, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDesign of PWM inverter pulse pattern is required to reduce harmonics generated by load change in output voltage. This paper shows this requirement is formulated as mixed sensitivity problem and proposes to apply H∞ control theory to this design.View full abstractDownload PDF (391K)
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