All issues
Volume 27, Issue 3
Displaying 1-19 of 19 articles from this issue
- |<
- <
- 1
- >
- >|
-
Tomoyuki AKASHI1991 Volume 27 Issue 3 Pages 255-262
Published: March 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA procedure for measurement of microbial activity becomes important in controling bioprocesses. This paper describes an on-line measurement method of a specific growth rate which is an index for the microbial activity. The specific growth rate is measured with a fractal dimension applied to a spacial pattern for a growing microorganism.
The relation between the fractal dimension and the specific growth rate is obtained through entropy of the pattern for the growing microorganism in the bioprocess. To clarify the procedure for measurement, a stochastic model of the measurement method is proposed for the growing pattern specified by the fractal dimension.
The fractal dimensions are calculated with image data for 4 kind of yeast. Based on the method, the results are compared with the experimental ones.View full abstractDownload PDF (1152K) -
Keiichi TANAKA, Seiichi KAKUMA1991 Volume 27 Issue 3 Pages 263-267
Published: March 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSFrequency stability and resettability of two stabilized 633nm He-Ne lasers are measured. The lasers are trial manufactures by a domestic production company. The laser is set in transverse magnetic field and generates intramode beat, the frequency of which is used for stabilizing the laser by thermal control. It has a quartz oscillator as a frequency standard. An iodine stabilized 633nm He-Ne laser is used as an sbsolute standard of optical frequencies. Beat frequency between the standard and test lasers are measured by a frequency counter. Each of the two test lasers shows frequency fluctuation of 1MHz peak to peak and frequency stability is estimated to be 2×10-9 for 6 to 8hrs measurements. For one of them the frequency monotonically decreased up to 35MHz during repeated mesurements for 3 months. The two test lasers showed a frequency difference of about 70MHz each other.View full abstractDownload PDF (715K) -
Yasumitsu KURANO, Kiyoshi YOSHIDA1991 Volume 27 Issue 3 Pages 268-275
Published: March 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe viscosity standard in Japan has been established and maintained with capillary master viscometers which are calibrated by the stepping-up method based on the kinematic viscosity of distilled water at 20°C and at atmospheric pressure. In order to improve the accuracy of kinematic viscosity measurements and to extend the temperature ranges of the viscosity standard, new capillary master viscometers with an automatic flow time detection system have been designed and constructed. Then, NRLM (National Research Laboratory of Metrology) has participated in the international comparison of ASTM (American Society for Testing and Materials) standard viscosity liquids organized by ASTM Committee D-02. 07 A since 1984 to confirm the international consistency of the kinematic viscosities determined in the temperature range -40 to 100°C by using new capillary master viscometers.
From the results of the comparison, the differences between kinematic viscosities obtained by NRLM and CIC (Cannon Instrument Company, U.S.A.) are -0.28 to 0.20%. The accuracy of kinematic viscosities of the ASTM standard viscosity liquids determined by capillary master viscometers is estimated to be within ±0.05% in two standard deviations.View full abstractDownload PDF (1752K) -
Sensor Fusion of Audio and Visual SensorsKota TAKAHASHI, Hiro YAMASAKI1991 Volume 27 Issue 3 Pages 276-282
Published: March 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA new method for adapting an acoustical sensing system to sounds by visual sensor data is proposed.
The acoustical processing part of the system is an intelligent sound sensing system, which can extract a target sound from other disturbance sounds if the envelope of the target signal is estimated.
The spatial filter technique is utilized for a visual image processing part of the system. A vertical-stripe spatial filter estimates the envelope of the sounds from sound sources swinging horizontally. A horizontal-stripe spatial filter estimates the envelope of the sounds from sound sources shaking vertically. Using spatial filter technique, the system can distinguish the target sound from other disturbance sounds by its property of moving. Furthermore, using the estimator of envelope of a disturbance sound also, the system can adapt to the sounds whose envelopes have any correlations each other.
Theoretical analysis and experiments demonstrated adaptability of a linear filter for acoustical signal paocessing only by visual information.View full abstractDownload PDF (969K) -
Hitoshi TAKATA1991 Volume 27 Issue 3 Pages 283-290
Published: March 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper we consider a computer method of the formal linearization for nonlinear systems. A nonlinear system is described by a system of nonlinear ordinary differential equations. A linearization function is given as a solution of a system of linear partial differential equations. It is solved by the procedure of weighted residual based on the orthogonal polynomials with the aid of computers. The error bound and the application of the method are also considered. Numerical examples show that the accuracy of the method is improved as the order of the polynomials increases.View full abstractDownload PDF (830K) -
Tadashi EGAMI, Toshiro UNOKI, Takeshi TSUCHIYA1991 Volume 27 Issue 3 Pages 291-297
Published: March 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, combination of the following three methods are proposed. (1) New trajectory planning, (2) Robust control system and (3) Zero error tracking compensation.
New trajectory planning method taking control ability of designed robot manipulator control system into consideration is described. It is made systematically without trial and error method on the basis of the frequency response of the designed control system.
Robust control system is applied to path control along with the trajectory planning method. In the robust control system, nonlinear compensation error and interference from the other arms are regarded as being equivalent disturbance signal and compensation action is applied by utilizing estimated value of the equivalent disturbance in discrete-time model. Moreover, zero error tracking compensation which guarantees unity gain and zero phase of the robust control system is added. Parallel drive robot manipulator is taken to be our example to show effectiveness of the combination of the three methods in simulation studies.View full abstractDownload PDF (871K) -
Kazuyuki JOYA, Katsuhisa FURUTA1991 Volume 27 Issue 3 Pages 298-305
Published: March 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIf all the roots of a polynomial lie in a prescribed domain D, we call the polynomial D-stable. As the monic polynomials of degree n with real coefficients are identified with points in Rn, we can consider the family of D-stable polynomials in the coefficient space.
In this paper we derive an explicit expression for the set of D-stable polynomials in the coefficient space, on the condition that D is a convex domain whose boundary is one of conic sections or a sector.
With the result, we also give a necessary and sufficient condition for convex combinations of monic D-stable polynomials to be D-stable.View full abstractDownload PDF (864K) -
Zenta IWAI, Atsushi OHTOMO, Ikurou MIZUMOTO1991 Volume 27 Issue 3 Pages 306-313
Published: March 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSRecently, the so-called simple adaptive control (SAC) techniques have been turned attention because of its high practical control performance in spite of its quite simple control structure. The method is fundamentally applicable to plants which satisfy the so-called almost strictly positive real (ASPR) condition.
In this paper, it is shown that, even if the plant contains some kinds of disturbances and nonlinearities and does not satisfy ASPR condition, the control performance can be improved quite well by adding a simple robust adaptive controller to the original SAC algorithm. Effects of such a robust controller are examined by a practical DC servo control equipment.View full abstractDownload PDF (1000K) -
Junichi IMURA, Toshiharu SUGIE, Tsuneo YOSHIKAWA1991 Volume 27 Issue 3 Pages 314-319
Published: March 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSRecently various adaptive robust control methods have been proposed for robot manipulators with unknown parameters or disturbances, which adjust input gain adaptively and make the system robust. But they are complicated in design, because they do not make good use of the robot dynamics.
In this paper an adaptive robust control scheme for robot manipulators is proposed based on dynamic control methods, which can be easily constructed using effective expressions of dynamic models of robot manipulators and has a good prospect on the determination of the input gain. This method can also achieve the specified tracking error bound after a finite transition time. Simulation results are given to illustrate the effectiveness of the proposed method.View full abstractDownload PDF (761K) -
Jyunsou KIMURA, Yukio NISHIMURA, Yoh YONEZAWA, Masahiro OHYA1991 Volume 27 Issue 3 Pages 320-325
Published: March 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSPredictive control of which input is constructed by using the future state is one of the most effective design method for the controlled object with time delay. But if unmeasurable disturbance is inflicted on the controlled object with time delay, it causes inaccuracy of the predicted state. As a result, a bad effect unexpectedly occurs on the control system.
The objective of this paper is to propose a design method for the object with time delay under the influence of periodic input disturbance.
First, a new predictor removing the prediction error by using periodicity of disturbance is provided. In case the state of the object are unmeasurable, the state estimated by an observer is used for prediction. A setting method of the observer gain is proposed in order to reduce the estimation error arbitrarily.
Secondly, on the construction of feedback control system using the predicted state, a determination method of the feedback gain is described. By this feedback gain, the state of the object can approach into an arbitrarily small domain in the vicinity of the equilibrium point.
The observer gain and the feedback gain are determined by using the positive definite solution of the corresponding Riccati equation respectively. These solutions guarantee the practical stability of the control system.
Lastly, the effectiveness of this design method is verified by numerical simulations.View full abstractDownload PDF (696K) -
Takashi OHNISHI1991 Volume 27 Issue 3 Pages 326-332
Published: March 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSOperations of refuse incineration plants involve many uncertain factors. They include human factors, the complexity of refuse burning phenomenon and the physical properties of refuse. On the other side, fuzzy control has been widely put to practical use as a rulebased controller, which applies the experience of skilled operators and the knowledge of experts. This paper describes a fuzzy control system for the refuse combustion process, consisting of two elements; i.e., a fuzzy sensing system and a fuzzy controller.
The fuzzy sensing system, located between the process outputs and the fuzzy controller, infers the situation of the plant replacing human observation. This concept is considered useful when it is difficult to collect manipulation rules directly from the process variables.
In the fuzzy controller, we propose an ordinal structure model of control rules, with the aim of reflecting the operator's sense of priority among the control rules. In this method, the inference results of each control rule are compensated according to the difference of priority and the relative magnitude of the premise. The aim is to simplify the procedure for partitioning the input space of the controller and also to reduce the number of control rules.
Some test runs on an actual 200t/d incineration plant are also presented. From these results, it is concluded that the system proposed is effective and practical for plant automation.View full abstractDownload PDF (971K) -
Haruaki OTSUKI, Toshio OGISO1991 Volume 27 Issue 3 Pages 333-340
Published: March 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA trajectory accuracy improvement scheme for a “serial-parallel-drive”, SCARA type robot arm is proposed. The serial-parallel-drive robot arm has the forearm motor on the upper arm coaxially, which drives the forearm through a parallel link mechanism. The scheme is composed of invariant dynamics design, decoupling compensation control, and inverse system computation. It cancels the inertia variation effects, coupling inertia effects, centrifugal and Coriolis torque effects, and response lag of the servo system. It simplifies the arm drive system dynamics into decoupled, linear, time-invariant one. Therefore, the computation requirement of the inverse system is reduced compared to the conventional inverse dynamics method. The scheme is applied to a SCARA type direct-drive robot arm with a 8bit MPU controller, and verified to be effective through simulation and real-time operation experiments.View full abstractDownload PDF (1555K) -
A Compensation of Frictional Force Using Computed Torque MethodKoichi YOSHIDA, Takayuki YAMADA, Takeshi TSUJIMURA, Tetsuro YABUTA1991 Volume 27 Issue 3 Pages 341-348
Published: March 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSComputed Torque Control Method is known very well as method to compensate complex non-lineality and coupling of multi-link robot maniuplator. In this method, it is necessary to determine a precise dynamic model and to estimate model parameters.
This paper proposes a disturbance compensation method for trajectory control of robot manipulator to compensate unknown dynamics such as friction for which we can not get mathematical expression and parameters precisely.
Although the disturbance compensation method has been designed in continuous-time system, a discrete-time control algorithm is necessary to implement to an actual system.
This paper proposes a new discrete-time control algorithm of the disturbance compensation method with regard to both a discretetime dead-time effect and noise reduction.
To evaluate the new control algorithm, it is applied to a parallel link robot arm. The experimental results show improvement of trajectory tracking performance in low frequency domain and reveal that this method can reduce real-time torque computation since the gravity force, the coriolis and centrifugal force are estimated as disturbance torque to compensate.View full abstractDownload PDF (1490K) -
Kensuke HASEGAWA, Hidemine OHNO1991 Volume 27 Issue 3 Pages 349-356
Published: March 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe paper deals with the deduction of the condition logic equations representing the relations between conditions in the condition/event (C/N) system from the S-invariant and the related token count equation defined in the ordinary Petri net.
The aim is to construct the powerful analytical tool for solving the problem how to find the equivalent C/E system with the less number of conditions than of conditions in an original C/E system.
This problem will be occured, e.g., in the logic circuit design from the specification of the discrete event control system represented by the C/E system.
At first, the concept of the minimum support nets (MSNs) in the ordinary Petri net are introduced corresponding to the basic S-invariants. This concept is applied to C/E systems by using the complement of condition, and the generalized MSN (including the quasi MSN) are introduced. The condition logic equations are deduced from the token count equations related to the generalized MSN by adopting the modulo 2 addition. The simple application of the equations to eliminate conditions in the C/E system and to obtain the equivalent C/E system are shown by an example.View full abstractDownload PDF (891K) -
Hideo TANAKA, Hisao ISHIBUCHI, Nobuyoshi MATUDA1991 Volume 27 Issue 3 Pages 357-364
Published: March 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSZ. Pawlak has proposed a new concept of approximate data analysis based on rough sets and applied it to medical analysis. Rough sets are defined by equivalence relations and the data base is called an information system. A method of reducing attributes in the given information system has been developed by equivalence relations with regard to attributes.
In this paper, we propose a new method of reducing information systems by considering the classification given by experts, although Z. Pawlak's method does not consider the given classification in reducing information systems. Thus our method can reduce more attributes than Z. Pawlak's method. Also, a method of constructing a fuzzy expert system is described by the proposed method of reducing information systems and by introducing fuzzy intervals represented as fuzzification of data values.
As an example, the fuzzy expert system for medical diagnosis is built by fuzzy inference rules. There are 367 fuzzy if-then rules constructed by the lower approximations which show consistency of the given data and the classification given by experts. It is very useful that inconsistency of test data and expert's diagnoses can be clarified by our approach.View full abstractDownload PDF (1046K) -
Teruyuki IZUMI1991 Volume 27 Issue 3 Pages 365-367
Published: March 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSMultiple random signals are used as excitation sources for identification of multi-variable systems. This paper proposes a new set of the weighting functions of filters which can generate N uncorrelated normal random signals from a single binary random signal.View full abstractDownload PDF (342K) -
Masafumi ITO, Kazuhiro HANE, Fumio MATSUDA, Yoshiki UCHIKAWA, Shuzou H ...1991 Volume 27 Issue 3 Pages 368-370
Published: March 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWe describe a technique for measuring the direction of a reference point easily and accurately. In the method, cross-hair diffraction beam, corner cube and an XY-scanner driven by piezo stacks are used. The accuracy for angular detection was about 10μ rad.View full abstractDownload PDF (863K) -
Kiyoshi NISHIYAMA1991 Volume 27 Issue 3 Pages 371-373
Published: March 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA new combination of a decaying exponential window and the previous proposed decaying spectrum estimation based on complex Kalman filter is discussed. In computer simulation, it is demonstrated that such a combination provides the spectrum improving both resolution and signal-to-noise ratio.View full abstractDownload PDF (394K) -
Application for Robot HandSatoshi IWAKI, Satoru MATSUO1991 Volume 27 Issue 3 Pages 374-376
Published: March 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper describes an application for robot hand by stable negative compliance control (SNCC). Kinematic phenomena “climbing a convex plane” is realized by stably setting diagonal factors of end-point compliance matrix to negative. This interesting phenomena can be applied to robot hand grasping or object recognition for a convex object. The proposed idea is applied to a planar 3-link DD arm and the successful experimental results are also presented.View full abstractDownload PDF (896K)
- |<
- <
- 1
- >
- >|