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Volume 26, Issue 1
Displaying 1-19 of 19 articles from this issue
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Yoshiya TERAO, Masaki TAKAMOTO1990 Volume 26 Issue 1 Pages 1-8
Published: January 30, 1990
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSMeasurements of low range air flow velocity have been important to monitor the ventilation rate in buildings and coal pits. In recent years air flow velocity measurement, especially in the range below 0.5m/s, has become more important in testing and controlling of industrial clean rooms.
However, there has been no practical standards for low range air flow velocity so that there is a major problem of incompatibility between velocimeters made by different manufacturers.
In the present study, the standard of low range air flow velocity has been established using a towing carriage which moves on a 45 meters long rail placed in an underground tunnel. An ultrasonic velocimeter was calibrated using this apparatus in the velocity range from 0.05 to 0.6m/s. As a result of detailed estimation it is found that the uncertainty of the calibration is sufficiently minimal.
In order to supply the standard, the secondary standard velocimeters of the major manufacturers and users were calibrated. The standard established in this research is expected to make a considerable contribution to accurate measurements of low range air flow velocities in various fields.View full abstractDownload PDF (1026K) -
Shogo TANAKA1990 Volume 26 Issue 1 Pages 9-15
Published: January 30, 1990
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn various marine constructions, searching for the pattern of seabeds is often done. This search is accomplished by analyzing the data provided by a sonar. However, surface waves of the sea cause the ship to heave and roll in the collection of the data. This means they disturb the sonar to collect exact data on the pattern of the seabeds. So, estimating the heaving and the rolling of the ship has a key in the exact recognition of the pattern of the seabeds. Exact estimation of these quantities also plays an important role in the program of building a rolling-less ship.
From these viewpoints, the present paper develops an automatic measurement system, which uses appropriately located two servo-type acceleration meters and estimates the heaving and the rolling of the ship by analyzing the outputs of the acceleration meters taking into account the wave properties which influence the ship's movement.View full abstractDownload PDF (956K) -
Gururaj K. RAO, Hiroshi KASHIWAGI1990 Volume 26 Issue 1 Pages 16-23
Published: January 30, 1990
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper deals with detection of pattern-sensitive faults in Random-Access Memories (RAM) using pseudorandom M-sequences. Two types of neighborhood around each cell are considered and two schemes for fault detection are proposed by appropriately choosing the test-sequences depending on the neighborhood. The conditions to obtain complete test-set and the nature of the test-patterns are analyzed. Due to the random nature of the test-patterns, it was found out that the schemes not only cover pattern-sensitive faults, but also cover decoder faults to a large extent. The effectiveness of the test sequences to some common fault types is analyzed in comparison to conventional schemes.View full abstractDownload PDF (941K) -
Mitsuo SATO, Hiroshi TAKEDA, Hiroshi SATO1990 Volume 26 Issue 1 Pages 24-30
Published: January 30, 1990
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, we consider the problem of estimating a periodic sequence of pulses driving an AR transfer system from its output pulse sequence contaminated by an observation noise. For this problem we discuss three estimation methods, Methods 1, 2 and 3, to estimate the input pulse sequence whenever one cycle is finished. Methods 1 and 2, which we present in this paper, are based on operations of taking an average with explicit consideration of the periodicity. Method 3 is obtained by applying a least square method, which is optimal in the sense of minimization of the noise power, to this problem. Asymptotic behavior of estimation errors by the three methods are examined, and it is shown that under any of these the error variance converges to zero asymptotically with the same order. Also, it is indicated that if the observation starts with some delay from driving start time the delay may have a considerable effect on transient behavior of the estimation error of each method. Furthermore, by numerical examples, it is shown that each method has similar estimation accuracy when there is no delay of the observation start time but when there is some delay the accuracy of Method 3, a least square method, grows down ramarkably while Methods 1 and 2, with rather simple operations of taking an average, hold their accuracy in a satisfactorily high range.View full abstractDownload PDF (905K) -
Akira KOJIMA, Kenko UCHIDA, Etsujiro SHIMEMURA1990 Volume 26 Issue 1 Pages 31-38
Published: January 30, 1990
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn the design of robustly stable feedback systems, the key step is to analyze the stability of closed loop systems in case nominal plant is perturbed. In this paper, robust stability of time delay systems is discussed. We propose a method to check the robust stability for time delay systems in case that the parameter perturbations occur in both lumped parameter part and distributed delay element. It is known that the properties of Lyapunov type operator equation of time delay systems are almost similar to those of finite dimensional case; for example, the time delay system is asymptotically stable if and only if there exists a unique positive definite solution for the Lyapunov type operator equation.
By using this property of Lyapunov type operator equation, we first derive an operator type condition of robust stability, in which the parameter perturbations are described as a bounded operator. Secondly, we derive a matrix type condition of robust stability, which is equivalent to the operater type condition. By using these preliminary results, we lastly propose a norm condition of robust stability in case that parameter perturbations are characterized with structural variables.
The method we proposed needs a positive definite self-adjoint solution to Lyapunov type operator equation. Averaging method can be applied for the approximate calculation of Lyapunov type operator equation, and the computational work needed to obtain the solution is shown to be quite moderate.View full abstractDownload PDF (967K) -
Setsuo SAGARA, Zijiang YANG, Kiyoshi WADA1990 Volume 26 Issue 1 Pages 39-45
Published: January 30, 1990
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper proposes an algorithm for parameter estimation of continuous SISO systems purely using a digital computer. The sampled input and output signals are passed through the low-pass IIR filters which are designed in continuous-time domain and then discretized by bilinear transformation. The low-pass IIR filters are introduced to avoid taking direct derivatives and to reduce the effects of measurement noise. This approach does not invole the problem of the initial conditions in contrast with the well known multiple integration approach. It is shown that the IIR filters are more convenient to be designed than the FIR filters of the linear integral filter approach.
If the pass-band is appropriately selected, the LS method is efficient for the case where measurement noise level is low. The application of an IV method in a ‘bootstrap’ fashion to the high measurement noise case is also considered to yield consistent estimates. Simulation results show that if the cut-off frequency of the filters is selected in a relatively wide range near that of the continuous system under study, the results of the estimation algorithm are quite satisfactory.View full abstractDownload PDF (919K) -
Shigenori OKUBO1990 Volume 26 Issue 1 Pages 46-53
Published: January 30, 1990
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSModel reference adaptive control system (MRACS) has become a high perfectible control system with many researches since the presentation by Monopoli. The problem of disturbance elimination and stability have been solved partially, but researches on nonlinear MRACS are not sufficient. There is no research on nonlinear MRACS of which the global stability is guaranteed. This paper shows the design of nonlinear MRACS and the proof of the global stability with using classification of norm for nonlinear functions. The MRACS of this paper has the construction as the combined system of nonlinear model following control system and exponential decay adjustable law by Kreisselmeier. The global stability can be proved with using classification to separate the nonlinear index into three cases (0≤γ<1, 1≤γ<2, 2≤γ) and solving the differential inequality for positive function analytically from the fact that parameter errors decay exponentially. As gradually γ is large, the nonlinear becomes difficult, so additive conditions to the controlled system increase. The MRACS of this paper is not only nonlinear but also multi-input and multi-output. Furthermore it is proved that the condition of strictly positive real is satisfied for stable nonminimum realizations of transfer function. We show the effectiveness of the design of this paper from numerical simulations for no disturbance and with disturbances.View full abstractDownload PDF (988K) -
Akira OHSUMI, Yuichi SAWADA1990 Volume 26 Issue 1 Pages 54-61
Published: January 30, 1990
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper deals with a new method of finite-dimensional control for a class of mechanically flexible systems subject to random disturbances, by reducing the distributed parameter system to a finite-dimensional one. The principal approach is to regard the observation spillover due to the uncontrolled modes as a colored observation noise and construct an estimator. Under certain conditions related to the number of sensors, this approach ensures that the direct decoupling of controller and estimator and the effect of observation spillover can be reduced so that the stability of the resulting system is guaranteed. Simulation studies for a simply supported or free-free beam are provided.View full abstractDownload PDF (920K) -
Koosuke HARADA, Gen ZHAO, Katsuaki MURATA1990 Volume 26 Issue 1 Pages 62-69
Published: January 30, 1990
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWith the cost of silicon and solarcells decreasing, the conversion of solar energy to electricity is increasingly becoming an economically viable alternative. However, the solar array power fluctuates considerably during each day depending on insolation level and weather conditions etc. Moreover, the current-voltage characteristic of solarcells varies due to temperature variations and secular changes etc. Hence a need is created to simply derive the maximum solar power whatever conditions are.
We here propose a novel interface circuit between commercial ac bus and solarcells using Van Allen's multivibrator. Based on the analysis of the characteristic of the multivibrator, we present a simple optimization method to change the output voltage of solarcells by small control current, adjust the quiescent point of solarcells and then follow the optimum quiescent point.View full abstractDownload PDF (1632K) -
Fujio HIROKI, Taiji MASUDA, Keijiro YAMAMOTO1990 Volume 26 Issue 1 Pages 70-75
Published: January 30, 1990
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIntending to develop a impact plane bending fatigue testing machine without mechanical moving part, a fluidic oscillator using supersonic bistable device has been design and tested.
The newly developed oscillator is a kind of the loaded oscillator which has the bifurcated outlet channels with load capacitances. As load capacitances, tanks or tubes are used to control the oscillating frequency. The main outlet ducts construct opposing nozzles, so that the output jet can keep the high power without losing energy through the load capacitances. A fatigue test piece is set between the opposing nozzles forming flapper-nozzle configuration and is vibrated by the alternately impinging jets.
It was revealed that a non-attachment device, ie, without load, the main jet flows equally into both outlets, is necessary for realizing the supersonic oscillator. The oscillation starts when the pressure in the load tank and that in the outlet duct increase up to the same value, viz., switching back pressure. The frequency of the oscillation is controlled independently of the supply pressure by using tubes as the load capacitances.View full abstractDownload PDF (819K) -
Vichai SAECHOUT, Michio NAKANO, Yoshiki MATSUO1990 Volume 26 Issue 1 Pages 76-80
Published: January 30, 1990
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe sinusoidal inverters which convert D.C. voltage source to A.C. voltage source by firing the switching devices with a suitable angles have been widly used in the A.C. machine drive system. To obtain the nearly A.C. output voltage it is necessary to determine the firing angles which produce the output voltage having the following properties, its low-oder harmonics distortion are eliminated and fundamental component is equal to A.C. reference and is insensitive to disturbance of system occuring from the fluctuation of D.C. voltage source or the load harmonics caused by nonlinear loads. There have been many schemes to give the firing angles so far, such as optimal firing angle solved by off-line computation, subharmonics modulation. By these schemes, however, the disturbance of system can not be suppressed.
This paper describes a new PWM control strategy for sinusoidal inverters. This scheme considers the average of gain between the output voltage and the A.C. reference as a criterion for determining the firing angles of the inverter. The theoretical analysis is presented and verified through the simulation. The simulation results show that by this scheme the low-order harmonics distortion are almost eliminated and the fundamental component is also regulated to the A.C. reference. Futhermore the output voltage is insensitive to influence of disturbance occuring from the fluctuation of D.C. voltage source.View full abstractDownload PDF (528K) -
Weijing ZHANG, Tadayoshi FURUYA, Kenji KUROSU1990 Volume 26 Issue 1 Pages 81-86
Published: January 30, 1990
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper provides a new approach to representation of figures by so called feature-lists. It is proposed to approximate a figure with a polygon, and the list of lengths and angles of the polygon are defined as feature-list of the figure.
Using feature-lists, similarity between two figures is evaluated simply by the matching situations of the two lists. Figure processing, such as composition and decomposition of figures, can be carried out very efficiently by adding or substracting the corresponding lists. Addition and substraction of two lists are given as formula in two tables.
Lucky Puzzle is solved as an example to show the practicability and effectiveness of this method. In the puzzle, seven pieces are composed into a given shadow figure.View full abstractDownload PDF (686K) -
Hisao MIYANO1990 Volume 26 Issue 1 Pages 87-92
Published: January 30, 1990
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSScaling algorithm for asymmetric similarity data is developed, based on the extended model of Krumhansl's distance-density model. The algorithm is constructed using the alternating least squares method, and its efficacy is examined by analyzing several artifitial data and journal citation data given by Weeks and Bentler.View full abstractDownload PDF (818K) -
Identification of Possibilistic Linear Systems by Quadratic Membership Functions of Fuzzy ParametersHideo TANAKA, Hisao ISHIBUCHI1990 Volume 26 Issue 1 Pages 93-100
Published: January 30, 1990
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWe have already formalized several models of the possibilistic linear regression analysis, where it is assumed that possibilistic parameters are non-interactive, i.e., the joint possibilistic distribution of parameters is defined by minimum operators. In this paper, we will deal with the interactive case in which quadratic membership functions defined by A. Celmins are considered. With the same view as described in our former studies, the possibilistic linear system with quadratic membership functions can be obtained by solving linear programming problems.
The joint possibilistic distribution of parameters defined by a positive definite matrix is interactive. This point is different from our former works, where fuzzy parameters are non-interactive. The fact that some parameters become crisp in our former works is criticized by A. Celmins. In response to his concern, we will propose the new method for data analysis with quadratic membership functions. Our problem under consideration is similar to one considered by A. Celmins, but the proposed approach is simpler and more understandable than his approach based on the least-squares fitting with a complex algorism. Furthermore, similar problems are discussed by H. Bandemer, where fuzzy observations are transferred into fuzzy parameters.
Our main concern is on a method of obtaining interactive fuzzy parameters into which fuzziness of data can be converted. Since our approach resorts to the linear programming, it is easy to apply our approach to real data analysis. This is very important for users who intend to analyse fuzzy data.
Numerical examples are shown to explain our approach.View full abstractDownload PDF (979K) -
Akira WATANABE, Kaoru WAKAIRO1990 Volume 26 Issue 1 Pages 101-107
Published: January 30, 1990
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA flight simulator is indispensable for aircraft research and development. The system has the following 4 main pieces of equipment: (1) cockpit system, (2) visual system, (3) motion system and (4) real time computer system.
Recently as the simulation scale has been enlarging, it is requested to improve the function of simulator. In order to increase the capability, the most effective way is to improve the function of the computer system. One of the ways is to use a much higher speed computer or to introduce a multi-computer system. The other one is to decrease a system overhead time caused by the interrupt processing and the coupling method among computers.
At NAL a multi-computer system is adopted. For a multi-computer system, the most important point is how to couple the computers. In the paper we present a method to reduce the system overhead time by introducing a high speed, independent repeating transfer data bus. Furthermore, we present a method that is effective to decrease the transfer delay. At last we show the propriety of the method by applying it to our flight simulator multi-computer system (NFCS).View full abstractDownload PDF (1055K) -
Li CAO, Akira KOBAYASHI1990 Volume 26 Issue 1 Pages 108-110
Published: January 30, 1990
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn an ordinal method for determining lens parameters, we have to find out the magnification and distances of object and its focused image from the optical center point using some suitable precise equipments.
We propose a new simple method to estimate lens parameters based on a least squares processing of the data obtained by measuring some pairs of relative working distance and back focus repeatedly without any precise equipment.View full abstractDownload PDF (309K) -
Jian-Xin XU, Hideki HASHIMOTO, Fumio HARASHIMA1990 Volume 26 Issue 1 Pages 111-113
Published: January 30, 1990
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, one kind of observers is proposed for MIMO systems. The designed observer can successfully estimate unknown states in spite of the existence of system uncertainties and nonlinearities. The advantages of the observer are demonstrated through some numerical example.View full abstractDownload PDF (301K) -
Yoshimi MUTOU, Kazuyasu HAMADA, Takashi MORISHITA1990 Volume 26 Issue 1 Pages 114-116
Published: January 30, 1990
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThere are some constraints for the application of the model reference adaptive control (MRAC) systems. In particular, if a plant has unmodeled dynamics, the global stability is not guaranteed.
In this paper, we try to apply the MRAC technique to the inverted pendulum system by the use of the robust adaptive algorithm in Ref. 3), and to investigate the availability of this algorithm.View full abstractDownload PDF (333K) -
Akihito SANO, Junji FURUSHO1990 Volume 26 Issue 1 Pages 117-119
Published: January 30, 1990
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSBy using a stable quantity ‘Quasi-Angular-Momentum’ which represent a state of quadruped walking system, we evaluated the degree of approximation of reduced order model which we derived. We also proposed a control method in which the quasi-angularmomentum is kept constant.View full abstractDownload PDF (399K)
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