All issues
Volume 41, Issue 5
Displaying 1-13 of 13 articles from this issue
- |<
- <
- 1
- >
- >|
-
Tomoyuki OSAKI, Naoya OOSHIMA, Takeshi SAITOH, Ryosuke KONISHI2005 Volume 41 Issue 5 Pages 383-387
Published: May 31, 2005
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSMethod of quartz crystal oscillator of odor sensors is drawing public attention recently. In this paper, we modulated gas flow used a magnetic valve in order to improve the rate of discrimination. Furthermore, we change into urethane resin the Film applied to a quartz crystal oscillator, and also report the result which used and discriminated the triangular wave in gas flow modulation. We tried discrimination of five herb species (Linden, Chamomile, Rose hips, Lavender and Lemon balm) using the BP (Back Propagation) method and SOM (Self-Organizing Map). The BP method must use the neural network of three hierarchy, in order to discriminate five herb species. However, this method is complicated. Then, the improvement of discrimination method was done by using SOM, which is simple one, compared with the BP method. The obtained discrimination result is 96.7% and the complexity of discernment has improved.View full abstractDownload PDF (2168K) -
Kenbu TERAMOTO, Kohsuke TSURUTA2005 Volume 41 Issue 5 Pages 388-395
Published: May 31, 2005
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSLamb waves are guided ultrasonic waves capable of propagating relatively long distances in plates and laminated structures, such as airframe skins, storage tanks and pressure vessels. Their propagation properties in these media depend on the vibrational frequency as well as on the thickness and material properties of the structure. Structural flaws such as disbonds, corrosion and fatigue cracks represent changes in effective thickness and local material properties, and therefore measurement of variations in Lamb wave propagation can be employed to assess the integrity of these structures. In this study, the local phase velocimetry based on the spatio-temporal gradient analysis is derived theoretically. The proposed method has an ability to characterize the phase velocity of the Lamb-wave propagation through the linearity among the 4-dimensional vector which is composed by following components: (1)a vertical (z-directional) displacement, (2)its vertical particle velocity, (3)x-directional and (4)y-directional out-of-plane strains. In this study, the computational process of the local velocimetry is discussed and their physical meanings are investigated through numerical and acoustical experiments.View full abstractDownload PDF (2518K) -
Yasuhiro WADA, Kimitaka TSUYUKI, Yousuke SOGA, Kazuhiro YAMANAKA, Mits ...2005 Volume 41 Issue 5 Pages 396-404
Published: May 31, 2005
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe following two characteristics have been well demonstrated about the feature of a point-to-point human arm movement on a plane. (1) The path is a roughly straight line, but is slightly curved. (2) The velocity profile is bell shaped with a single peak. Several models have been proposed to explain these features. Four criteria for trajectory planning based on optimal principles have been proposed. They were the minimum hand jerk criterion, the minimum angle jerk criterion, the minimum torque change criterion, and the minimum commanded torque change criterion. It has shown that trajectories generated by the minimum commanded-torque change model correspond well with measured trajectories in a horizontal and sagittal work space. In the paper, we measured point-to-point movements in three-dimensional space and performed comparative examinations quantitatively between arm posture planned by the optimal criterion and measuerd arm posture. Next, we performed comparative examinations between the measured trajectories and the optimal trajectories based on minimum angle jerk criterion, minimum torque change criterion and minimum commanded torque change criterion. Finally, we report that both of the measured hand trajectory and arm posture were closest to the trajectory and posture predicted by the minimum commanded torque change criterion.View full abstractDownload PDF (2122K) -
Kenji KAWASHIMA, Koichi IGARASHI, Ryota KODAMA, Tomonori KATO, Toshiha ...2005 Volume 41 Issue 5 Pages 405-410
Published: May 31, 2005
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSSome pneumatic systems require to measure the differentiated value of pressure with high resolution and high response. In former research, a pressure differentiator which is constituted of an isothermal chamber, a laminar flow element with narrow pipes, and a diaphragm type differential pressure gauge is proposed. In this paper, in order to improve the dynamic characteristics of the pressure differentiator and make the sensor compact, slit type micro channels are fabricated with Micro Machining technology. Firstly, the principle and the design method of the sensor are discussed. Then, machining processes are explained. Finally, the results of performance tests are shown. The results indicate the high performance of the developed sensor.View full abstractDownload PDF (2403K) -
Takashi SHIMOMURA2005 Volume 41 Issue 5 Pages 411-418
Published: May 31, 2005
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper addresses a new framework of control design, which allows for parameter-dependent Lyapunov functions for continuous-time systems. The control design is performed in an extended space rather than the space where the problem is originally given. Inverse use of the elimination lemma can explore this framework. This paper focuses on the H2/H∞ problem in multiobjective control design, robust H2 performance against polytopic uncertainties, and gain-scheduled control for linear parameter-varying systems. However, more other control problems could be handled with this framework. Through an illustrated example of a two-mass, one-spring, and one-damper mechanical system, the applicability of the proposed method is demonstrated.View full abstractDownload PDF (1861K) -
Computational Efficiency Improvement Based on Search Region Bound and Subproblem ReductionMichihiro KAWANISHI, Shinichi OMOTO2005 Volume 41 Issue 5 Pages 419-426
Published: May 31, 2005
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, Primal Relaxed Dual (PRD) method for Bilinear Matrix Inequalities (BMI) is studied. Firstly, the properties of BMI PRD method between search region and computational efficiency is analitically studied. Based on these properties, new BMI PRD method using search region bounding operation with Lagrangian function and lower bound is proposed. Secondly, in order to reduce the number of subproblems, subproblems reduction method is introduced. The effectiveness of the proposed methods is evaluated by the numerical experiments.View full abstractDownload PDF (1828K) -
Hiroaki MUKAIDANI2005 Volume 41 Issue 5 Pages 427-436
Published: May 31, 2005
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, H∞ state feedback control for weakly coupled systems is investigated. The attention is focused on the design of the high-order approximate H∞ controller which is based on the numerical solutions. A novel contribution is that a new iterative algorithm is derived by combining Newton's method and the fixed point algorithm. As a result, H∞ controller can be constructed in the same dimension of the subsystems. It is newly proved that the proposed algorithm has the quadratic convergence. Moreover, it is shown that the resulting controller achieves O(ε2κ) approximation of the optimal H∞ cost. As another important feature, if the coupling parameter is unknown, it is also shown that the parameter independent decentralized controllers achieve O(ε) approximation.View full abstractDownload PDF (2228K) -
Toru ASAI2005 Volume 41 Issue 5 Pages 437-443
Published: May 31, 2005
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSSwitching in control systems often causes bumpy responses. Recently, some methods have been proposed to analyze L2 gain from disturbance inputs before switching to control outputs after switching for systems with uncertainty. However, the results are conservative, since the analysis is aimed for robust performance problems and the conditions given in those methods are sufficient conditions. On the other hand, by considering the corresponding nominal case, this paper gives necessary and sufficient conditions. The resultant conditions are given in terms of both Lyapunov equations and linear matrix inequalities. Moreover, the results provide generalization of the Hankel norm analysis. A numerical example shows the effectiveness of the proposed gain and the analysis conditions.View full abstractDownload PDF (1527K) -
Masuhiro NITTA, Kenji SUGIMOTO, Atsushi SATOH2005 Volume 41 Issue 5 Pages 444-451
Published: May 31, 2005
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper proposes a new method for identifying a multi-input multi-output autoregressive model without observation of input signals. This is achieved by making use of an independent component analysis technique, which rebuilds signals from their linear mixture under the assumption that the source signals are independent. The method firstly introduces an augmented state-space expression of the observed signal, and then adopts a numerical search using the so-called natural gradient. Finally, numerical simulation has been carried out to illustrate the effectiveness of the proposed method.View full abstractDownload PDF (1675K) -
Takahiro ENDO, Fumitoshi MATSUNO2005 Volume 41 Issue 5 Pages 452-458
Published: May 31, 2005
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, we discuss a force control problem for a constrained one-link flexible manipulator based on distributed parameter model. The flexible manipulator is making contact with an object. In order to solve the force control problem, we propose a simple feedback control law. This proposed control law consists of bending moment at the root of the flexible manipulator and its derivative, which regulates simultaneously the contact force and the rotational angle of the motor without information of rotational angle and contact force. We prove the exponential stability of the closed-loop system by using energy multiplier method. As the control law is derived based on the distributed parameter model, we can avoid the drawbacks resulting from finite dimensional approximation.View full abstractDownload PDF (1612K) -
Takeshi MIZUNO, Yuji HIRASAWA, Masaya TAKASAKI, Yuji ISHINO2005 Volume 41 Issue 5 Pages 459-465
Published: May 31, 2005
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA self-sensing magnetic suspension system with an H-bridge hysteresis amplifier is developed. Since the H-bridge drive circuit consists of a pair of transistors and a pair of diodes, the amplifier operates in two quadrants; the output current has one polarity while the polarity of the voltage applied to the coil is reversed alternatively. The switching characteristics of the amplifier are studied both analytically and experimentally. The measurement results show that the switching frequency is proportional to the air gap between the electromagnet and the suspended object, and insensitive to the value of current command. A digital control system is developed in which the displacement of the suspended object is estimated based on the period measurement of the switching signal. Self-sensing suspension is achieved with the developed hysteresis amplifiers and the digital control system.View full abstractDownload PDF (1621K) -
Yuhki KOSAKA, Akira SHIMADA2005 Volume 41 Issue 5 Pages 466-472
Published: May 31, 2005
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper proposes a motion control technique for robot manipulators. And the strongest point of the technique is high performance on vibration suppression based on an exact dynamic model. The robot control system proposed is characterized by a function that considers the rotor dynamics including rotor masses and the low rigidity in the mechanical reduction gears like the Harmonic Drive Gears. The controller is designed as a sampled-data optimal servo control system with a digital disturbance observer expressed by a state space form. Finally, an experimental results on a real two degrees of freedom robot manipulator are shown by using the servo acceleration sensors.View full abstractDownload PDF (3226K) -
Noboru HAYASAKA, Shingo YOSHIZAWA, Naoya WADA, Yoshikazu MIYANAGA, Nob ...2005 Volume 41 Issue 5 Pages 473-480
Published: May 31, 2005
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWhen a speech recognition system is used in real environment, noises cause a serious problem in the system. In this paper, we propose a method which normalizes feature parameters after filtering the time trajectories of both the power spectra and the log power spectra. As a result of the isolated word recognition experiment where fifteen kinds of noises were added, higher recognition rates was obtained than conventional method by Spectrum Subtraction (SS) and RelAtive SpecTrAl (RASTA). But the proposed method has problems such as processing time and groupe delay of FIR filter. This paper reports on the outline of LSI to solve these problems.View full abstractDownload PDF (4013K)
- |<
- <
- 1
- >
- >|