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Volume 29, Issue 11
Displaying 1-15 of 15 articles from this issue
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Atsuo MUTOH, Shuichi NITTA1993 Volume 29 Issue 11 Pages 1251-1260
Published: November 30, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, the analog switch with amplification-function, which can treat differential input signals, is proposed. Analog switches with amplification is constructed by means of turning on/off the power supply of IC operational amplifier. Providing amplification-function to analog switches, it is expected that high accuracy measurement can be realized with less mutual interference between signals, and analog switches' application areas are expanded further and simple systems' organization can be realized.
The guide to analog input multiplexer design and its fundamental specifications are shown.View full abstractDownload PDF (1574K) -
Kazuyoshi KUBO, Nobuharu AOSHIMA1993 Volume 29 Issue 11 Pages 1261-1268
Published: November 30, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSNew method of measuring reverberation decay curves was proposed, aiming to apply the curves which are used in the acoustics, to the analysis of transient characteristics of dumped systems.
This method was derived using the Wigner distribution applied to a noise model of measuring reverberation.
The reverberation decay curves for computer generated impulse responses are calculated by the Schroeder, Fourier transform and proposed method. And a comparative study was made.
The proposed method are shown to contain the following desirable properties:
1) Calculated decay curves are free from the band pass filter characteristics.
2) Processing time is equivalent to one of the Fourier method. Especially, to analyze up to the half of the Nyquist frequency, the proposed method gives double resolution with equivalent processing time, or needs half of processing time with equivalent resolution, comparing to the Fourier method.
3) Spectral leakage along the frequency direction is extremely less. Therefore higher discrimination of some resonant components is attained.
4) Desirable decaying figure are calculated, even though the narrow band pass filter is considered.
5) Even if the passed band contains no resonant components, the reverberation curves presents the desirable initial decay, and the rest of the part remains in the lower level.
6) Effect of the finite integral in terms of time is less. The desirable decay figure are given in the wide range of time.
7) The reverberation decay curves are not always monotonous decrease. Temporary exchange of energy with sidebands makes the curves uneven.View full abstractDownload PDF (1415K) -
Ikuro MORITA, Terunobu TADA1993 Volume 29 Issue 11 Pages 1269-1275
Published: November 30, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSAs a diagnostic method of cage rotor in an induction motor, the stator current monitoring or the air gap flux monitoring has been developed. However, the air gap monitoring method can not be applied to every case because it is necessary to install a search coil on the stator.
In this paper, as a simpler diagnostic method, we studied on the leakage flux monitoring method. In this method, any pre-installation of a search coil to motor is not needed and the cage rotor can be diagnosed by the leakage flux waveforms and the feature frequency components of its spectra.
First, the space distributions of leakage flux are clarified by the analyzed and measured results. Next, we present the feature harmonics detector which rejects the normal harmonic components of leakage flux and confirm the effectiveness of this detector. Finally, the measured results obtained by the motor with artificial faults such as broken bars, demonstrate the availability of those analytical results and this method. As the results, it became possible to estimate quantitatively the leakage flux magnitude in the case of rotor faults and to prognosticate the cage rotor faults.View full abstractDownload PDF (913K) -
Wataru KASE, Katsutoshi TAMURA1993 Volume 29 Issue 11 Pages 1276-1282
Published: November 30, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSGiven a transfer function matrix N(s)D-1(s), the problem discussed in this paper is to find an orthogonal matrix pair [N(s)-D(s)] to [DT(s) NT (s)]T. A calculation method of the orthogonal pair is presented where only elementary real matrices operation needs. It is shown that an annihilating matrix of an observability matrix of N(s)D-1(s) provides the orthogonal pair. Some related problems in linear system theory are also discussed.View full abstractDownload PDF (1194K) -
Koichi KOGANEZAWA1993 Volume 29 Issue 11 Pages 1283-1292
Published: November 30, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper deals with an on-line parameter estimation of continuous-time system with unknown order and input delay. The recursive running DFT (RRDFT) is employed to calculate instantaneous system gains at specified frequency points. System parameters besides input delay are recursively updated with respect both to the frequency points and their order by the proposed recursive algorithms. The input delay is easily estimated at the final procedure of the proposed estimation scheme. Two examples of the computer simulations are demonstrated to verify the proposed algorithms and estimation schemes.View full abstractDownload PDF (1213K) -
Shuichi SASA1993 Volume 29 Issue 11 Pages 1293-1301
Published: November 30, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA Kalman filter is applicable to a state estimation problem in a linear stochastic system. In this case, the filter must take into account information concerning system model structure, initial condition, and probabilistic characteristics of noises. In this paper, the robustness of a Kalman filter against uncertainties of noise covariances is discussed. When covariance matrices of process noise and observation noise change from nominal level multiplied by random variables, a Kalman filter designed for nominal noise condition is shown to be more robust than observers designed by pole placement technique in terms of the amount of deviation of the estimation accuracy from a nominal value. Considering the above feature, it becomes possible to design a kind of robust state estimator by adding the amount of variation of estimation accuracy to a nominal performance index. This idea is then demonstrated using a simple example.View full abstractDownload PDF (1636K) -
Kazunobu YOSHIDA, Hisashi KAWABE, Yukio NISHIMURA, Yoh YONEZAWA1993 Volume 29 Issue 11 Pages 1302-1310
Published: November 30, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn linear systems with state and control constraints, an initial state is admissible if the subsequent motion of the system satisfies the constraints. The set of all possible such initial conditions is the maximal set of admissible initial states, denoted by S*, which has important applications in the analysis and design of closed-loop systems with such constraints. A linear discrete-time time-invariant control system, x(t+1)=Ax(t), with constraints of the type, y(t)=Cx(t)∈Y, is considered.
A new method for constructing the set S* has been given on the basis of the results obtained by Yoshida et al. in 1985. The investigation in the dual space has led to an efficient algorithm where the dual set of S*, i.e. R*, is considered instead of S*. Both S* and R* are convex polyhedrons that the vertices of one set can express the other set. The properties of R* and its characterization are studied. The algorithm for constructing the set R* can be summarized as follows: Let R(0) be the convex combination obtained from the column vectors of CT. Apply AT to the vertices of R(0) to obtain new vectors and take convex combination of these vectors and R(0) to make R(1). In much the same way as this, proceed to generate R(2), R(3), …. If the new vector is not a vertex of the set, stop the subsequent application of AT to the vector. The set R(j) is a monotonically nondecreasing set and its limit is R*.
Since this algorithm removes the vectors unnecessary for constructing R* at each stage and uses an efficient LP obtained from the study in the dual space, the calculation amount can be saved considerably as compared with the one proposed by Gilbert and Tan in 1991.View full abstractDownload PDF (1307K) -
Kou YAMADA, Keiji WATANABE, Masamitsu TSUCHIYA, Tsutomu KANEKO1993 Volume 29 Issue 11 Pages 1311-1319
Published: November 30, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, we present a design method of repetitive control systems for linear time-invariant systems. This system consists of FIR digital filter and a filtered inverse. The output can follow a periodic reference input rapidly with small steady state error.View full abstractDownload PDF (1556K) -
Tsutomu MITA, Kang Zhi LIU, Kazunobu KURIYAMA1993 Volume 29 Issue 11 Pages 1320-1329
Published: November 30, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn the ordinary H∞ control, weighting functions are assumed not to have unstable poles so that the stabilizability of (A, B2) and the detectability of (A, C2) are satisfied. However we sometimes face a problem where the weighting functions have jω poles when we want to design a servo system. In this paper, we solve this problem and show when and how H∞ control system is designed by the conventional H∞ control theory.View full abstractDownload PDF (1488K) -
Sadamu INAISHI, Hirofumi EGUCHI, Tadashi YAMASHITA1993 Volume 29 Issue 11 Pages 1330-1336
Published: November 30, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA dynamic system model often contains some structured uncertainties which can be expressed by parameter perturbations. Keel et al. developed an algorithm for obtaining a robust state feedback controller, which is available to time-invariant system. They selected the state feedback controller to realize the most robust one by minimizing a certain index with respect to the model uncertainties. It is, however, not sure to the system containing time-varying uncertainties.
In this paper, we extend this method to the system with time-varying uncertainties which are expressed by the linear combination of time-varing parameters and the time-invariant matrices characterizing the structures of uncertainties. As a result, we show the sufficient condition for exponential stability of the time-varying system.
It is also investigated that the minimum value of the index depends only on the assigned eigenvalues of the closed loop system. Moreover a new algorithm using penalty method, which restricts the domain for seeking the minimum value of the index, is presented. An example of designing lateral autopilot system of a missile is shown as application.View full abstractDownload PDF (1361K) -
Toshiharu KAGAWA, Masashi SHIMIZU, Katuya HONDA, Osamu OYAMA1993 Volume 29 Issue 11 Pages 1337-1341
Published: November 30, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSControl valves play very important role as final control elements in process control system and most of them are driven by the pneumatic pilot valve.
Electro-pneumatic positioner systems are analysed considering non-linear property of a pneumatic pilot valve, and characteristic model are derived. The action of the pneumatic pilot valve is constituted with different modes, so there exists a strong non-linearity.
The experimental data are in satisfactory agreement with the calculated responses considering the pilot valve non-linearityView full abstractDownload PDF (1653K) -
Takashi SHIMA1993 Volume 29 Issue 11 Pages 1342-1351
Published: November 30, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWe will propose new global optimization procedure which utilizes the concept of tunneling algorithm in this paper. There exist two phases in the tunneling algorithm for global minimization problems, 1) minimization phase and 2) tunneling phase. In the minimization phase, the local minimum is searched. In the tunneling phase, the point in the lower valley is searched.
In this paper, we will propose an annealing type of random tunneling search in the tunneling phase. First, we set the temperature at some degree and generate the increment (δx) from the local minimum (x*), according to the Cauchy distribution. A new point x(=x*+δx) is evaluated whether it is in the lower valley or not. If the point in the lower valley is not found after the predetermined number of trials, the temperature is set a little lower according to its cooling schedule and we repeat the same procedure again.
The wide range of search becomes possible owing to the property of Cauchy distribution and temperature cooling. We also abopt multistart scheme in order not to miss the global minimum.
Several test problems are solved. The proposed method hardly misses the global minimum and is very promising for future application research.View full abstractDownload PDF (1636K) -
Keiko TAKAHASHI, Kiyohiko NAKAMURA, Atsunobu ICHIKAWA1993 Volume 29 Issue 11 Pages 1352-1360
Published: November 30, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe computational complexity of reachability problems for petri nets is analyzed. A new class of Petri nets each of which is composed of some layers of state machines is introduced. The class is defined by the following conditions:
1) Connections among the state machines are acyclic and direction is from the first layer to the second, from which to the third, and so on.
2) Each state machine receives inputs directly from at least one upper state machine.
3) In each state machine, any state either receives only one transition or delivers only one transition.
This class includes nets which are not state machines or marked graphs, and its reachability problems are solvable in pseudo-polynomial time. It is proved that the reachability problem for the class is solvable in deterministic polynomial time under certain restricted initial marking: an algorithm that solves the introduced reachability problem in pseudo-polynomial time is proposed. The paper also shows a procedure that may find a Petri net in the proposed class in deterministic polynomial time, where it does not find all Petri nets in the class.View full abstractDownload PDF (1627K) -
Naoki TAKUMA, Koichiro DEGUCHI, Iwao MORISHITA1993 Volume 29 Issue 11 Pages 1361-1368
Published: November 30, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA new method for image figure segmentation using morphological techniques is proposed. Morphological skeleton transform, which extract a medial axis of an input figure, is known to have an advantage that the original figure can be reconstructed from its resulted skeleton. At the same time, the skeleton is dissociated at constricted parts (or necks) of the input figure.
In this method, we utilize these two properties for segmentations. First, we take the morphological skeleton for the input image figure. Then, we reconstruct the original figure part by part separatedly from each of dissociated skeletons, and obtain segmented figures.
It will be a great advantage that, in this method, such a global image analysis as figure segmentation can be achieved only using steps of local morphological operations.View full abstractDownload PDF (2622K) -
Kajiro WATANABE, Liya HOU1993 Volume 29 Issue 11 Pages 1369-1378
Published: November 30, 1993
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIncipient fault diagnosis of a process is prerequisite to maintain the process safety. But the diagnosis job is very difficult because the symptom of fault in the incipient stage is quite slight. The job becomes more difficult when the incipient fault with multiple causes occurs. It is also not easy to obtain the fault knowledge, i.e., the measurement data in the faulty condition with multiple causes.
This paper describes how to calculate measurement data in a faulty condition with multiple causes from the measurement data each in faulty condition with single cause. Further in this paper we present a macro-architecture of neural networks that can effectively learn and store the data as the knowledge in variety of faulty conditions including faults with single cause and those with multiple causes and that can accurately diagnoses these faults.
The macro-architecture of networks has the hierarchical structure in which the first stage network learns and stores the data of faults with single cause and the networks in the second stage store the data of faults with multiple causes. The allocation of the fault knowledge into networks of the macroarchitecture makes the diagnosing space narrower and leads to efficient and accurate diagnosis even for the faults with multiple causes.
Diagnosis via the macro-architecture of networks for faults with variety of combinations of causes was accurate.View full abstractDownload PDF (1311K)
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