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Volume 33, Issue 5
Displaying 1-19 of 19 articles from this issue
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Masaaki UEKI, Akira OOIWA1997 Volume 33 Issue 5 Pages 317-321
Published: May 31, 1997
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA laser interferometric oil manometer is developed for use as a national primary standard in the pressure range up to 1000Pa. The heterodyne interferometer using a Zeeman stabilized He-Ne laser was used to detect the displacement of oil surfaces which reflect the laser beam directly. A phenyl ether diffusion-pump oil (NEOVAC-SY, Matsumura Oil Co. Ltd.) with low vapor pressure, suitable density and viscosity is employed as the manometer fluid. The density of the manometer fluid was measured using pyknometers and its value at 32°C was 916.329kg/m3 with an uncertainty of 27ppm. The total uncertainty of the new manometer is evaluated to be (27ppm+0.5mPa) for gauge-mode pressure.View full abstractDownload PDF (2143K) -
Makoto KANEKO, Mitsuru HIGASHIMORI, Toshio TSUJI1997 Volume 33 Issue 5 Pages 322-330
Published: May 31, 1997
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSAn algorithm for detecting the shape of 2D concave surface by utilizing a tactile probe is proposed. Pulling a tactile probe whose tip lies on an object's surface can be easily achieved, while pushing it is more difficult due to stick-slip or blocking up with irregular surface. To cope with the difficulty of pushing motion on a frictional surface, the proposed sensing algorithm is based on the pulling motion of tactile probe from a local concave point to an outer direction. The algorithm is composed of three phases, local concave point search, tracing motion planning, and infinite loop escape. We show that the proposed algorithm runs until the tactile probe detects every surface where it can reach and touch. We also show some computer simulation and experimental results obtained along the proposed algorithm.View full abstractDownload PDF (3153K) -
Hiroshi SATO, Kajiro WATANABE, Kenichi MATSUBARA1997 Volume 33 Issue 5 Pages 331-336
Published: May 31, 1997
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA vortex whistle has a simple structure with only three components. The frequency of the whistle sound can be adjusted by the amount of blowing. The sound frequency is linearly proportional to the amount of flow in the wide flow range. But when blowing it, we feel strong reaction. It means the whistle has the certain pressure loss. Thus it can be a good flowmeter when the problem of the pressure loss is solved. Here we investigate the flow characteristics of the whistle to the solve the problem.
We carried out variety of experiments for variety of the vortex whistles to know the characteristics. I.e., we investigate the relation between the flow and sound frequency, the flow and pressure loss, the pressure loss and the dimensions of the whistle components and the temperature characteristics. From the experiments, we built a pressure loss experimental model and find condition of how to reduce the pressure loss. Finally we show a design condition of how to design the 6-type flowmeter as an example.View full abstractDownload PDF (1493K) -
Nobuhiro SHIMOI, Shuichiro KOGA, Kohji ITOH, Fujio IITAKA, Yoshiaki SH ...1997 Volume 33 Issue 5 Pages 337-343
Published: May 31, 1997
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSAmong the types of sensors currently used for detecting objects buried underground are the radar types such as microwave pulse sensors, FM-CW and CW sensors as well as magnetic types.
However, since these sensors are housed in caster or tire type frames, vibrations resulting from the ground surface conditions in transporting as well as operating these devices produces a marked effect on their detection characteristics.
For this reason, in investigations performed with the commonly used FM-CW radar, the noise of signals reflected from the ground surface due to vibrations increases and the task of processing images from the signals reflected off of the target object becomes difficult.
In this paper, we propose the use of a housing structure for sensors based on an air-cushion method as one means for overcoming such problems. With this method, the angle between the sensor and ground surface as well as the antenna position can be kept fixed which is an effective way of preventing detection signal weakening due to noise from vibrations.
We also verify the effectiveness of this method with basic experimentation and discuss the results of our study of the characteristics of antenna position stability and vibration in the detection of buried objects.View full abstractDownload PDF (1958K) -
Hiromitsu KUMAMOTO, Ichiro SAKAMOTO, Hiroaki KAWABATA1997 Volume 33 Issue 5 Pages 344-351
Published: May 31, 1997
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA self-tuning PID controller is proposed for regulation and tracking problems of first and second order lag systems. A PID self-tuning problem is defined by introduction of a first-order-lag reference model. Structural differences in PID and adaptive controllers are pointed out. A differential equation is derived for self-tuning of PID gain parameters. Output error convergence to zero is proven together with boundedness of relevant parameters and variables. A persistent excitation condition is given for PID gain parameter convergence to the exact model matching value. Robustness for a typical type of additive disturbance is proven. A numerical simulation and a temperature regulation experiment for an existing incinerator demonstrate the proposed self-tuning PID controller.View full abstractDownload PDF (1039K) -
Convex Analysis Approach Using Linear Matrix InequalitiesSeigo SASAKI, Kenko UCHIDA1997 Volume 33 Issue 5 Pages 352-358
Published: May 31, 1997
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSUsing an extended quadratic Lyapunov function of the form V(x)=xTP(x)x, we derive a sufficient condition that an input-affine polynomial-type nonlinear system is internal stable and the L2-gain is less than or equal to some given positive constant. The condition is given as Riccati-type inequality, for P(x), which depends on the state. We can obtain the solution P(x) as a polynomial function by solving linear matrix inequalities, and determine the region of internal stability. We also illustrate that the proposed method is effective through a numerical example of bilinear systems.View full abstractDownload PDF (1395K) -
Masanori TAKAHASHI, Ikuro MIZUMOTO, Zenta IWAI1997 Volume 33 Issue 5 Pages 359-367
Published: May 31, 1997
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper deals with the design problem of adaptive stabilizing controllers for MIMO plants with unknown orders. A design scheme for an output feedback based adaptive control system, which has hierarchical structures derived from backstepping strategies, is proposed for MIMO plants with unknown orders but with known relative MacMillan degrees which correspond to relative degrees for SISO case. It is also shown that all the signals in the resulting control system are bounded, and the output of the plant converges to zero asymptotically.View full abstractDownload PDF (1803K) -
When Position of the Mass Center of a Target Object is UnknownTomohide NANIWA, Suguru ARIMOTO, Kenzo WADA1997 Volume 33 Issue 5 Pages 368-374
Published: May 31, 1997
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA learning control method and an adaptive control method are proposed for coordinated control of multiple manipulators even when position of the mass center of a target object is unknown. Proposed methods can achieve exact tracking of any desired trajectories of each joint of the manipulators and so-called “internal force” which does not affect motion of the object.
Firstly, it is shown that dynamics of whole coordinated control system composed of multiple manipulators and a target object can be regarded as a dynamics of a single manipulator moving under geometric constraints in the joint-angle coordinate system. This implies that control of both the trajectory of the object and the internal force is regarded as that of both the joint angle trajectory and the contact force of a geometrically constrained manipulator. In addition to this, based on the passivity property of the dynamics and the orthogonality between the joint torque caused by the internal force and the joint angle velocity, conventional methods of learning control and model-based adaptive control for a geometrically constrained manipulator are extended to coordinated control of multiple manipulators in the joint coordinate system.
Effectiveness of the proposed methods is illustrated by computer simulation results based on a dynamics model of coordinating two 3-DOF manipulators.View full abstractDownload PDF (2377K) -
Jun-ichi IMURA, Keigo KOBAYASHI, Tsuneo YOSHIKAWA1997 Volume 33 Issue 5 Pages 375-383
Published: May 31, 1997
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, we propose a control method for nonholonomic systems expressed by the chained form, where the exponential convergence to the desired final state is guaranteed and the desired transient response is achieved. Next, we propose a trajectory generation method for the chained system, which gives a systematic procedure to find a reference trajectory that passes several given points at each specified time and exponentially converges to the origin. Finally, our method is applied to control of a 4-wheeled car. In this case, to express all the state of the 4-wheeled car by the chained form, it is required to use several coordinate frames interchangeably. Thus the above method is extended to the case where several coordinate frames are needed. In addition, a simple simulation result is shown to verify the effectiveness of our method.View full abstractDownload PDF (1299K) -
Krit CHONGSRID, Shinji HARA1997 Volume 33 Issue 5 Pages 384-391
Published: May 31, 1997
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, we propose a new balancing coordinate for the continuous-time system embedded in a sampleddata system which is a natural extension of the frequency weighted balanced realization of the continuous-time system to incorporate hybrid input and output weights. We show that the matrix which transforms the coordinate of the continuous-time system to the balanced coordinate can be calculated from the weighted controllability grammian and the weighted observability grammian. We then apply the new balanced truncation method to the problem of plant reduction for sampled-data systems, and an algorithm is proposed for obtaining a low order discrete-time controller by plant reduction based on a successive approximation. A numerical example illustrates the advantage of the proposed method.View full abstractDownload PDF (2332K) -
Gan CHEN, Toshiharu SUGIE1997 Volume 33 Issue 5 Pages 392-396
Published: May 31, 1997
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe structured singular value μ is effective for system analysis and compensator synthesis. However, since it is difficult to compute it analytically, its upper bound is used in most cases. This paper gives a new upper bound of the structured singular value μ based on parameter dependent multipliers. Numerical examples show its effectiveness.View full abstractDownload PDF (1050K) -
Norihiro NISHIUMA, Hajime FUTATSUGI, Hidenori KIMURA1997 Volume 33 Issue 5 Pages 397-402
Published: May 31, 1997
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe problem of controlling the Air-Fuel Ratio can be reduced to the problem of estimating air mass absorbed into cylinder. In current commercial engines, air mass taken into cylinder is estimated by table look-up. This method is incapable of coping with secular change of the engine. Also, to make tables for every kind of engine requires enormous amount of manpower. To circumvent these difficulties, we propose a model-based method using extended Kalman filter. The effectiveness of our method is demonstrated by simulation in comparison with experimental data.View full abstractDownload PDF (1336K) -
Young Soo SUH, Seiichi SHIN1997 Volume 33 Issue 5 Pages 403-408
Published: May 31, 1997
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper is concerned with a new delay-dependent stability condition for state-delayed systems. This stability condition is based on discretization of the infinite-dimensional kernels of state-delayed systems. The discretized system of a state-delay system is not finite dimensional; thus the stability condition cannot be derived by simple discretization. In this paper, the discretized system is divided into a finite-dimensional part and an error part. The stability condition is derived based on the finite-dimensional part explicitly taking account of the error part. The lifting technique that is used in sampled-data control is used to derive the stability condition. The stability condition is given in the form of an H∞ norm test for discrete-time systems. The stability condition is shown to converge to the exact stability condition as the order of discretization approaches infinity.View full abstractDownload PDF (1505K) -
Naoyuki TAMARU, Joji YAMAGUCHI, Yasuhide NISHIDA, Fumikazu OHIRA1997 Volume 33 Issue 5 Pages 409-416
Published: May 31, 1997
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSAn offset compensation method using reflection-type photoelectric switches is studied with the aim of achieving a low-cost and highly accurate positioning control system. This system uses an open-loop control type robotic mechanism consisting of pulse motors and ball screws to reduce the cost. To make an optical connection in an automated optical cross-connect switching system, the robot must position optical fiber plugs at desired positions. The “on” region of the photoelectric switches is determined by scanning the plug grasped by the robot hand in front of the photoelectric switches. Offset compensation is achieved by calculating the difference between the initial position of the center of the region and the newly measured value. Experimental results show that the repetition error of the offset detection is less than 5μm (about 0.1% of the control position pitch) and the position variation of the center of the “on” region is less than 30μm when the distance between the switch and the plug is 0.1-1.0mm. The feasibility of this compensation method using photoelectric switches was confirmed by installing it into the automated optical cross-connect switching system.View full abstractDownload PDF (1610K) -
Tetsutaro ONO, Hideo SAITO, Sinji OZAWA1997 Volume 33 Issue 5 Pages 417-423
Published: May 31, 1997
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA sound source separation that identifies mixed tones from more than one sources is one of the important task when transcribing from a musical acoustic signal to a musical score. This paper presents a method of sound source separation using GA. In this method, after segmentation in time domain, tone parameters such as notes or volume are estimated by minimizing error between input spectrogram and a spectrogram which is synthesized by some templates using these parameters. The minimization of parameters is done by GA and Hill-climbing. We will show that this method costs lower than normal methods.View full abstractDownload PDF (1936K) -
Satoshi MURATA, Kohji TOMITA, Haruhisa KUROKAWA, Shigeru KOKAJI1997 Volume 33 Issue 5 Pages 424-432
Published: May 31, 1997
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSSelf-assembly and self-repair algorithm for homogeneous distributed mechanical systems is proposed. We focused on a category of a distributed system composed of numbers of identical units which can dynamically change connections among them. Each unit has an onboard micro-processor and local communication between neighboring units is assumed to be available. A group of the unit with random configuration at the initial time metamorphoses into desired shape by cooperation of the units. This process called “self-assembly” is realized by homogeneous software. An extension of this process, “self-repair” is also examined. In self-repair, cut off of an arbitrary part of the system is considered. When some part of the system detects a damage the whole system degenerates and reconstructs itself.View full abstractDownload PDF (2812K) -
Shinichi KIMURA, Masato TAKAHASHI, Toshiyuki OKUYAMA, Shigeru TSUCHIYA ...1997 Volume 33 Issue 5 Pages 433-440
Published: May 31, 1997
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSAdaptation to partial failure is one of the most important requirements in space robotics, since space robots cannot be repaired after they have been launched. We proposed a decentralized autonomous control algorithm of hyper-redundant manipulators that use parallel processing with very low-performance processors to achieve this adaptation. In this paper, some of manipulator joints are locked at a certain angle by computer simulation and the adaptability for the failure of the control algorithm is assessed. The control algorithm successfully continued the positioning task at the rate of more than 90 percent, even after half of its joints had failed. The control algorithm is also compared with behavior-based control architecture.View full abstractDownload PDF (3555K) -
Reiko TANAKA, Satoru IWATA, Seiichi SHIN1997 Volume 33 Issue 5 Pages 441-447
Published: May 31, 1997
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper investigates fault-tolerance of homogeneous systems that consist of a number of identical subsystems. In order to retain the fault-tolerance of large-scale systems, not only the reliability of each component, but also the design of a whole system counts for much. We carried out quantitative evaluation of fault-tolerance in terms of autonomous controllability for systems with different structures. The failure patterns to cause the systems to be uncontrollable can be found merely by structural information. In consequence of this investigation, we focused our attention on symmetrical structures of the systems, and applied group representation theory to our analysis.View full abstractDownload PDF (1411K) -
Kazunori HASE, Nobutoshi YAMAZAKI1997 Volume 33 Issue 5 Pages 448-454
Published: May 31, 1997
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA neuro-musculoskeletal model which is similar to the actual man was developed in order to predict a recovery level of pathological gait and to restore locomotion of human ancestor. The musculoskeletal system was modeled as two dimensional nine rigid links and twenty-two muscles in the sagittal plane, and as two rigid links and two muscles in the horizontal plane. The neural system was modeled as a rhythm generator composed of fourteen neural oscillators. Genetic algorithms were used to determine those neural parameters. Bipedal walking was synthesized as mutual entrainment between the rhythmic activities of body dynamics and the oscillation of neural system. Criterion for the parameter searching was defined firstly as walking distance and the number of steps until falling down. After a stable walking was achieved, then the parameters were adjusted to agree with the measured walking, in terms of stride length, walking cycle, and joint moments. The synthesized walking with an actual human body proportion was in good agreement with the actual walking. As examples of different body proportions, infant and ape models were simulated with minimum energy criterion instead of the criterion of similarity to actual walking. They were also agreed to those of actual walking. These results show that walking pattern corresponding to body shape could be synthesized by the proposed method.View full abstractDownload PDF (3151K)
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