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Volume 32, Issue 11
Displaying 1-12 of 12 articles from this issue
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Kenji KAWASHIMA, Toshinori FUJITA, Toshiharu KAGAWA1996 Volume 32 Issue 11 Pages 1485-1492
Published: November 30, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIt is not so easy to measure a flow rate of compressible fluids directly, because not only the pressure but also the temperature must be measured. In this paper, a chamber called an “Isothermal Chamber” is proposed. Then, a simple method to measure compressible fluids using this chamber is proposed. The isothermal chamber is a chamber that can almost realize isothermal conditions due to the larger heat transfer area and heat transfer coefficient by stuffing the steel wool into it. As the state during charge or discharge is almost isothermal, an instantaneous flow rate could be obtained using only a pressure in the chamber. At first, the characteristic of the isothermal chamber was examined by experiments and simulations. Then, the steady flow rate of air was measured by the proposed method. To confirm the effectiveness of the method, the measured results were compared with the results obtained from the sonic venturi nozzle. It became clear that the proposed method can measure the steady flow rate of air within 1 percent of errors.View full abstractDownload PDF (1262K) -
Masayuki SUZUKI, Shigeaki KOBAYASHI, Yoshinori ANDO1996 Volume 32 Issue 11 Pages 1493-1500
Published: November 30, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIt is very effective to design the control law by using the singular perturbation method when there are parasitic elements in the control systems. In this paper the singularly perturbed systems with structured uncertainties are concerned. At first it is shown that the original system is quadratically stable for the sufficiently small singular perturbation parameters when both of the reduced system and the boundary layer system are quadratically stable. Next the quadratic stabilizing control is designed for the singularly perturbed system. The quadratically stabilizing control law for the original system is composed from the control laws that stabilize each subsystem quadratically. However this composite control cannot be applied to the system directly because that contains the system uncertainties. So the composite control with the nominal values only is employed. Then it is shown that the nominal value composite control stabilizes the original system for the sufficiently small singular perturbation parameters quadratically. The effectiveness of the new control law is confirmed by the simulation for the two-mass system.View full abstractDownload PDF (1449K) -
An Interpolated Model via a Coprime Factorization ApproachEiichi MURAMATSU, Masao IKEDA1996 Volume 32 Issue 11 Pages 1501-1509
Published: November 30, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSModeling for a multi-input multi-output plant with variable operating conditions is considered. The plant is represented as a linear interpolation of proper stable coprime factorizations of the transfer functions describing the plant at two representative operating points. The coprime factorizations are not unique in general and the interpolated model is dependent on the choice of the factorizations. To choose the coprime factorizations appropriately so that the interpolated model closely approximates the real plant, we propose a norm-minimization problem for the difference of coprime factorizations between the real plant and the interpolated model at a specified operating point. It is shown that the optimal solution for the problem can be obtained using a BMI (bilinear matrix inequality) in the state space.View full abstractDownload PDF (1485K) -
Ri-yao SONG, Shintaro ISHIJIMA, Akira KOJIMA1996 Volume 32 Issue 11 Pages 1510-1517
Published: November 30, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, instead of trying to establish the design method of general purpose observers, we propose a design method of the special purpose observers which will be used in the feedback linearization of MIMO linearizable nonlinear systems. The basic idea of this method is as follows. We assume there exists an observer and construct a so-called pseudo-linearized model by imposing the observer-based linearizing control law on the original system first and then design the observer. It is striking to note that the nonlinear observer thus obtained possesses a standard linear structure, which makes a practical nonlinear closed-loop control system considerably easy to implement. manipulator case is presented to illustrate the design method. A sufficient condition for Separation Principle in the weak sense that the control design does not influence the observer design, and the observer design does not depend on the new input is also derived.View full abstractDownload PDF (1104K) -
Tohru KAWABE, Tohru KATAYAMA1996 Volume 32 Issue 11 Pages 1518-1525
Published: November 30, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper we consider a robust control design of a car with 4-wheeled steering (4WS) system using a Minimax optimization method. It is assumed that cornering powers of the front and rear wheels are modeled as parameters with bounded uncertainty due to the change in tire characteristics and that the steering angle of front wheel is operated by a driver. Based on the feedback signal from a yaw angle velocity, we develop a method of minimizing the H2 norm of a transfer function from the steering angle of the front wheel to the slip angle maximized by the uncertain parameters. The result of several simulation studies shows the robustness of the proposed 4WS system to change in driving conditions.View full abstractDownload PDF (1026K) -
Hitoshi MAEKAWA, Kazuo TANIE, Kiyoshi KOMORIYA1996 Volume 32 Issue 11 Pages 1526-1534
Published: November 30, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDynamic grasping force control for a multifingered hand is proposed and investigated. The grasping force of the finger is dynamically adjusted according to the tactile feedback so that each fingertip force always stays inside the friction cone detected by the tactile sensor and the fingertips maintain firm contact without any undesired slip nor detaching from the surface of the object while grasping it. The proposed method can be applied for real-time control of the hand since it requires few numerical calculations. The validity of the proposed method is experimentally confirmed using a two-fingered hand with finger-shaped tactile sensors.View full abstractDownload PDF (2125K) -
Satoshi ITO, Hideo YUASA, Koji ITO1996 Volume 32 Issue 11 Pages 1535-1543
Published: November 30, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSPhysiological experiments suggest that spinal network, called by CPG, generates locomotion patterns. Many papers have formulated it at the neural oscillator level, but only a few papers include the mechanical model in pattern formulation. This paper will consider both oscillator and mechanical model of the quadruped. The oscillator model generates the locomotion patterns of mechanical model, while the mechanical model provides the energy consumption based on which the oscillator model determines the generating pattern.
Quadrupeds might select the locomotion patterns in order to consume less oxygen. The experiments in horses have supported this hypothesis. This paper derives the energy evaluation from two types of energy definition, which reflects the experimental result in horses very well. Our formulation connects with leg swing amplitude, i.e., the swing amplitude determines the energy expenditure. Simulations show that the simplified mechanical model can walk with less energy by changing the generation of locomotion patterns in oscillator model.View full abstractDownload PDF (1616K) -
Eizo UEYAMA, Hideo YUASA, Shigeyuki HOSOE, Masami ITO1996 Volume 32 Issue 11 Pages 1544-1552
Published: November 30, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn many conventional image recognition methods, distances among pixels are rarely taken into consideration explicitly because images are processed in the form of vectors. Then the nunber of connection among pixels is in direct proportion to that squared of pixels. It is thought that this problem may be got over by reducing connections among distant pixels, for correlations among neighboring pixels are larger than among distant pixels in general images. This idea is realized by methods based on the autonomous decentralized system. This research is the first try to solve the problem of figure-ground separation for dynamic image with this method. The separation mentioned above is to extract the part (figure) at where motion velocity is different from the background (ground) in the dynamic image. This process consists of two phases. First we execute provisional separation using spatial differences of optical flow calculated locally at each pixel. Unfortunately, this provisional separation by local operation may include certain classification error. Then next we correct them by dynamical interactions among neighboring pixels. Now, problem of explosion in number of connection among pixels never occur because this recognition system is realized with Ginzburg-Landau equation which can be calculated by local operations. This recognition system is superior in error ratio to the method based on Bayes decision which uses global information and is the best method of linear separation. Furthermore, this system can execute the separation of dynamic image made of random dot pattern which have been thought to be difficult to separate.View full abstractDownload PDF (2669K) -
Yasunari YOKOTA, Akira IWATA, Yukio YOSHIDA1996 Volume 32 Issue 11 Pages 1553-1559
Published: November 30, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA new method for subband coding of Electro-cardiogram (ECG) using a pyramid-type non-orthogonal subband filter which is designed by considered to stochastic property of the ECG is proposed. In a data compression of Holter ECG, reducing a calculation cost for the compression is as important as achieving higher compression performance because of limitation of electrical power consumption. Since the calculation cost in subband coding is depend on the number of taps of the subband filter, designing a subband filter with less number of taps is an important issue. We then designed subband filter which has higher coding gain for objective ECG by improving degree of freedom by excluding condition of linear phase property and orthogonality of the subband filter. By applying the filter to the coding of ECG's in MIT/BIH arrhythmia database, we demonstrated that the equivalent coding performance of 5 taps sub-band filter designed by proposed method requires about 12 taps orthogonal wavelet filter, which means reduced calculation cost of filtering.View full abstractDownload PDF (1074K) -
Susumu HASHIZUME, Yutaka MATSUTANI, Katsuaki ONOGI, Yoshiyuki NISHIMUR ...1996 Volume 32 Issue 11 Pages 1560-1565
Published: November 30, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA partial language can describe the concurrent behavior of condition/event nets (C/E nets) correctly. The authors have studied the construction problem for C/E nets with the specification described by a partial language. This problem can be solved by finding all atoms compatible with the specified partial language. An atom compatible with a partial language X is a C/E net with one condition and a set of events, Tn, which generates the partial language restricted to Tn, X/Tn. The paper first shows that an atom compatible with X can be extracted from a D-clique of X. It next proposes an algorithm for finding all atoms compatible with X.View full abstractDownload PDF (1332K) -
A Basic Study for Tactile AidsChikamune WADA, Shuichi INO, Tohru IFUKUBE1996 Volume 32 Issue 11 Pages 1566-1568
Published: November 30, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWe have found that the tactile threshold and the quality of the sensation are greatly influenced by the skin temperature of a fingertip for both the vibratory and the non-vibratory stimulation. These findings are useful to design tactile aids using the combination of the above two stimulation.View full abstractDownload PDF (359K) -
Masaya SEKIMOTO, Takehiko HORITA, Sumitoshi OGATA1996 Volume 32 Issue 11 Pages 1569-1571
Published: November 30, 1996
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe persent paper describes the better understandings on smoothness and periodicity of time series signals by a conventional technique based on the fractal theory. It deals with the model fractal signals and the natural observation and reveals the applicability of the fractal analysis.View full abstractDownload PDF (313K)
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