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Volume 30, Issue 9
Displaying 1-20 of 20 articles from this issue
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Zhisong CHEN, Yoshikazu HAYAKAWA, Seizo FUJII1994 Volume 30 Issue 9 Pages 999-1004
Published: September 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThere are a number of plants whose dynamics change according to their operating conditions. For such plants, gain scheduling techniques are suggested. In this paper, the stabilization problem of plants with variable operating conditions is considered. The plant is supposed to be described as one-parameter family of plants over RH∞. The controller is assumed to be designed in the same form as the plant description. From a complex function theoretic point of view, a necessary and sufficient condition for the closed-loop system to be stable is derived.View full abstractDownload PDF (1223K) -
Suguru ARIMOTO1994 Volume 30 Issue 9 Pages 1005-1012
Published: September 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper introduces a quasi-natural potential in robot dynamics, which induces a type of sinusoidal position (joint-angle) feedback with saturation in servo-loops. By means of SP-D (Saturated Proportional and Differential) feedback, not only the robot dynamics incorporated with these servo-loops but also the residual error dynamics between the desired and actual joint trajectories satisfy the passivity with respect to the residual input torque and a linear sum of residual velocity and saturated residual position outputs. It is shown by taking advantage of the hyper-stability theory that in the case of set-point control an independent “hyper-stable servo-loop” constructed from a PI feedback of such a linear sum in addition to the SP-D feedback gives rise to the globally asymptotic stability. It is further shown that in the case of trajectory tracking the passivity of residual robot dynamics with SP-D feedback loops plays a vital role and eventually leads to the adaptability in model-based adaptive control and the learnability in iterative learning.View full abstractDownload PDF (1220K) -
Kiyoshi NISHIMOTO1994 Volume 30 Issue 9 Pages 1013-1019
Published: September 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper a 3D sensing device from a single perspective view to determine the 3D attitude of a camera will be presented. The measuring system is consisted of a CCD camera and a triplet straight lines at right angles to each other located in 3D-space. The positions and orientations of a camera are obtained from the images as the projection of these lines. First, it is proved that the admissible solutions can be analytically calculated by solving the quadratic equations derived from image lines and they can be easily reduced by some simple rules. Furthermore, the errors of the 3D attitude due to the presented method will be examined. The triplet of straight lines are composed of three fluorescent lamps perpendicular to each other, which are respectively mounted along the X, Y, and Z axes of world coordinate system. The camera has a visual field of 320×200 pixels. From the experiments, in spite of low resolution of camera the following good results can be obtained 1) the error in camera position is within 3%. 2) the tilt, pan and roll angles of the camera can be precisely measured by 1 degree. 3) this method is very useful for a robotic vehicle due to the simple algorithm and fast computation.View full abstractDownload PDF (1637K) -
Kenichi KUROMORI, Shigeru GOTOH, Yoshinori MATUNAGA1994 Volume 30 Issue 9 Pages 1020-1026
Published: September 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSElectromagnetic flowmeters has been widely used since the introduction of pulsed DC excitation type in mid 70's. Pulsed DC excitation has improved the zero stability resulting higher accuracy, which is 0.5% of rate.
However, the type of pulsed DC excitation is liable to indicate significant fluctuation when applied to some kinds of slurry or low conductive liquids.
This paper describes particular characteristics of the flow-induced noise picked-up through the electrodes and proposes the technique called dual frequency excitation in order to reduce the flow-induced noise. This excitation method was realized by applying the magnetic field whose waveforms are superposed by low and high frequency. Measuring principle, practicable means and test results of the technique are demonstrated.
The dual frequency excitation has proved to be effective for reduction of the flow-induced noise without losing the advantageous features of good zero stability and quick response.View full abstractDownload PDF (1286K) -
Teruo YAMAGUCHI, Hiro YAMASAKI1994 Volume 30 Issue 9 Pages 1027-1034
Published: September 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSFor the advanced visual sensing system operating in a structurally unconstrained environment, it is important to measure its self-motion coincidently, because the motion of its platform is not always controlled for sensing.
In this paper, a new principle of angular velocity estimation utilizing a circular pipe filled with liquid and its associated method of measuring pressure distribution are proposed.
It is proved form Navier-Stokes equation that the gradient of fluid pressure and the centrifugal force of rotating liquid are balanced in hydrostatic condition. By applying this fact, it is shown that the difference of average pressure on two concentric cylindrical walls is in proportion to the square of angular velocity. To measure the pressure on the walls, two sheets of piezoelectric polymer film are used. The pressure applied to the membrane bent along a cylindrical surface causes the tension stress along the film and it polarizes electric charge on the both faces of the film. The charge can be collected by the evaporated electrodes and it is equivalent to calculating the average pressure on the wall.
In the first experiment, the size and material suitable for the angular velocity sensor are estimated from a fluidic numerical simulation. In the second experiment, it is proved that our trial sensor can transduce the angular velocity to the polarized charge on the surface of piezoelectric film. Even when the sensor is rotated in eccentric conditions, the final output voltage of the sensor is almost independent of it.
It is expected that this sensor can be extended to a simple three-dimensional rate gyroscope which does not require any excitation.View full abstractDownload PDF (1437K) -
Yasuhiko MUTOH1994 Volume 30 Issue 9 Pages 1035-1041
Published: September 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe inverted interactorizing is the basic technique for the model matching control, the adaptive control, the decoupling control, the disturbance decoupling control, etc. However, this technique can be applied only to the minimum phase plant because all zeros of the plant are cancelled by the closed loop poles. This is due to the fact that the interactor matrix corresponds to zeros at infinity of the plant. In this paper, the generalized inverted interactorizing of linear multivariable non-minimum phase plants by the state feedback is concerned. This is the problem to find the state feedback which makes the closed loop transfer matrix coincide with the inverse of the generalized interactor which corresponds to not only zeros at infinity but also finite unstable zeros of the plant. Since it can be shown that this state feedback cancels only stable zeros of the plant, the closed loop system is internally stable. If the plant is a minimum phase system, the generalized interactor reduces to the ordinary interactor, so the proposed method can be regarded as the generalized technique of the inverted interactorizing to the non-minimum phase systems. As a special case of the inverted interactorizing, it is also shown that the plant is decouplable and internally stable if and only if its generalized interactor is diagonal.View full abstractDownload PDF (916K) -
Hiroaki YAMAGUCHI1994 Volume 30 Issue 9 Pages 1042-1050
Published: September 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a method to use a single pole-zero cancellation that is located on 1+j0 on complex plane for a control and presents a sliding mode control with the cancellation.
When the pole-zero cancellation is assigned in the unstable region, a controlled output diverges. Therefore the pole-zero cancellation is usually located in the asymptotically stable region. If a single pole-zero cancellation is situated on the unit circle on the complex plane, the value of the controlled output will depend on the initial value of both the output and the target, because the unit circle is a boundary between the unstable region and the asymptotically stable region in discrete-time systems. Therefore the single pole-zero cancellation on the unit circle has been avoided on designing the control systems.
In this paper the effectiveness of utilizing the single pole-zero cancellation on 1+j0 is described. With the cancellation, the sliding mode control presented in this paper achieves the perfect tracking when a system identification is complete and furthermore, achieves the convergence of the output into the target without a parameter identification when the system identification is not complete. The sliding mode control does not require a system order that is indispensable to the parameter identification, therefore it is robust to unmodelled dynamics.View full abstractDownload PDF (1522K) -
Izumi MASUBUCHI, Atsumi OHARA, Nobuhide SUDA1994 Volume 30 Issue 9 Pages 1051-1059
Published: September 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper proposes a design method of robust servosystems. The plant we consider is assumed to have structured uncertainties which are represented by matrix polytopes in the state space equation. We construct the control system as follows. First, we quadratically stabilize the control system containing a integral compensator and guarantee to track a constant reference signal. Next, closed-loop poles are clustered robustly in a specified region. Further, we give an upper bound of tracking errors of controlled output and control input in L2 norm sense and minimize it subject to the uncertainties. To construct a compensator, we parametrize stabilizing compensators and reduce the above design problem to a convex optimization on the parameter space.View full abstractDownload PDF (1024K) -
Sadayuki JITSUHARA, Masatoshi NAKAMURA, Yasuyuki IKEGAMI, Haruo UEHARA1994 Volume 30 Issue 9 Pages 1060-1068
Published: September 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSAn appropriate control strategy for an ocean thermal energy conversion (OTEC) plant is required to attain a high efficiecy and stability. This paper proposed a controller design for an OTEC plant based on reduced order model. We constructed a reduced model in which the turbine inlet temperature and turbine outlet temperature were controlled by a warm sea water pump and a cold sea water pump. Based on the reduced order model, we designed a controller for the OTEC plant of 1000kW. We evaluated the proposed controller by using a detail OTEC plant model which could faithfully represent the actual plant, and obtained a satisfactory control performance for vapor temperature control using the proposed controller. The controller will be used effectively to control the electric power of actual OTEC plants of any output size.View full abstractDownload PDF (1856K) -
Kanya TANAKA, Akira SIMIZU, Khoichi SAKATA1994 Volume 30 Issue 9 Pages 1069-1076
Published: September 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a new design scheme of discrete-time adaptive pole-placement control for a pneumatic servo system in the presence of disturbances. Disturbances treated here are described as time-polynomial expressions. In this design scheme, a controller containes a faculty for eliminating the influence of disturbances. This paper shows experimental results where a pneumatic servo system is subjected to constant disturbances such as stick fractions and additive external forces. In this experiment, we compare this design scheme with a conventional design scheme. As the results, this design scheme shows superior control performance such as a accurate positioning in the presence of disturbances.View full abstractDownload PDF (1193K) -
Takashi OYABU, Haruhiko KIMURA1994 Volume 30 Issue 9 Pages 1077-1083
Published: September 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThere are three main disasters in domestic environments detectable by sensors, such as fires, gas leaks and generation of carbon monoxide gas. Besides these, there are spontaneous disasters, for instance, earthquakes, etc. A few systems for the three disasters have been developed. Recently, the systems are studied using fuzzy reasoning.
In this paper, a system, which can find the disasters, is being studied using OPS5 system. OPS5 is one of the tools which build up the expert system. The system can find the disasters in 2 minutes in accordance with the differential characteristics of the sensor outputs for sham experiments. The differential coefficients are introduced in every 15 seconds from sensor outputs. Four kinds of sensors are used in this system, namely a combustible gas sensor, a pair of carbon monoxide gas sensors, a temperature sensor and a humidity sensor. Rete algorithm is adopted in the matching processes of the system.View full abstractDownload PDF (1108K) -
Koji MIYAJIMA, Anca RALESCU1994 Volume 30 Issue 9 Pages 1084-1092
Published: September 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWe believe that an image understanding system should achieve results comparable to the human image understanding. Object recognition is an important part of image understanding. Typically, recognition is achieved by reasoning on the image processing results. In existing work, statistical, probabilistic and evidential (Dempster-Shafer theory) methods are used to treat the uncertainty associated with this reasoning. However, simplifying assumptions concerning the importance of, and the interaction between sources of evidence characterize these methods.
We propose a model based, object recognition method using fuzzy logic and capable of addressing the above issues. The object model is a part-of hierarchy. Each node is defined by fuzzy set valued attributes. When included, spatial relations between components are represented by fuzzy sets. A fuzzy measure captures interactions between attributes. Image processing results are propagated to a node by integration with respect to this fuzzy measure. When spatial relations are included, the recognition of nodes and relations are propagated to the level of a triplet (two nodes and a spatial relation). Integration with respect to a fuzzy measure on the collection of items (triplets, or nodes) propagates the recognition to higher levels. The fuzzy framework offers a unified approach to representation and reasoning while incorporating the user's subjectivity. Results of initial experiments are discussed.View full abstractDownload PDF (3406K) -
Kajiro WATANABE, Kazumasa SERIZAWA, Liya HOU1994 Volume 30 Issue 9 Pages 1093-1099
Published: September 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe artificial neural network of the perceptron type can be effectively applied to various fields as one of the learning machines. The feature of the neural network is that it has the ability of associative memory and can generalize the contents in the memory for recognizing input patterns. The back propagation algorithm is widely employed as the most stable learning algorithm. But the algorithm may lead to a very long learning time if the learning rate is selected improperly.
This paper presents a new algorithm that can select the optimal learning rate adaptively under the assumption that the local error function can be approximated by a quadratic function, and describes the characteristics of the proposed algorithm. Several typical patterns are learned by both the conventional and the proposed algorithms. The proposed algorithm yields a faster convergence due the adaptive optimal search of the learning rate than the conventional back propagation algorithm with a fixed learning rate.View full abstractDownload PDF (1310K) -
Hisao ISHIBUCHI, Akihiro MIYAZAKI, Kitaek KWON, Hideo TANAKA1994 Volume 30 Issue 9 Pages 1100-1108
Published: September 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWe propose an approach to the handling of missing inputs in neural networks for constructing neural-network-based diagnosis systems from incomplete data with missing attribute values. In our approach, each unknown attribute value is represented by an interval which includes all the possible values of that attribute. Therefore the incomplete data with missing attribute values are transformed into interval data. Then, three learning algorithms for multi-class classification problems of interval input vectors are derived in a similar manner as the back-propagation algorithm. Four classification rules based on interval output vectors from trained neural networks are also proposed. The proposed approach is applied to the medical diagnosis of hepatic diseases. High performance of the neural-network-based diagnosis system constructed by our approach is demonstrated by comparing it with the existing fuzzy-rule-based diagnosis systems.View full abstractDownload PDF (1684K) -
Keisuke KINOSHITA, Koichiro DEGUCHI1994 Volume 30 Issue 9 Pages 1109-1116
Published: September 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a solution to the optimal camera movement for 3-D shape recognition.
Our solution method involves the following steps. We capture sequence of images from the moving camera and then recognize the 3-D shape of the objects by applying Kalman filtering. Each object is identified by a few points on the object, which we term the object points. We are able to estimate the accuracy of the object point location by means of the corresponding co-variance matrix.
Depending on this accuracy, we assign recognition priority to the objects. Unrecognized objects are assigned higher priority values compared to the objects which are partially recognized or completely recognized. Note that our optimal camera movement depends on the priority values. But the priority values change dynamically, and also new objects appear in the image view. That means the camera movement also has to be decided dynamically. The camera movement is viewed as the composition of translational and rotational movements. The angle made at an object point by the translational motion of the camera is defined as the disparity angle of the object point. The translational component of the camera should be such that the sum of the disparity angles weighted by the priority values of the object points must be maximum. However, if the translational component turns out to be too large, it becomes difficult to correspond the object points. The movement, therefore, should be restricted within some small value.
The rotational component, on the other hand, should be such that the objects must be retained within the image view for a long time. Because, to converge appropriately, Kalman filter requires a large number of images of the same object.
The method provided here is an efficient solution of dynamically determining the camera movements fulfilling all the above requirements.View full abstractDownload PDF (2381K) -
Chikara MIYATA, Hiroshi KASHIWAGI1994 Volume 30 Issue 9 Pages 1117-1119
Published: September 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA theoretical study is made on the fault detection of logical circuit by use of M-Sequence Correlation method. The relation between input-output correlation function and logical circuit are investigated. We have shown that the structure of the circuit under test is estimated to some extent from the observation of input-output correlation function.View full abstractDownload PDF (391K) -
Hiromu INOUE1994 Volume 30 Issue 9 Pages 1120-1122
Published: September 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper describes methods of finite element subdivisions of a large conductor on which an LCD type voltage indicator is set. Typical three methods are tested by using surface charge method. One of them was in agreement with the experimented result. The method can prevent number of subdivisions from increasing geometrically in the calculation of the voltage that induces in the indicator.View full abstractDownload PDF (387K) -
Hisato KOBAYASHI, Hideyuki MASUBUCHI1994 Volume 30 Issue 9 Pages 1123-1125
Published: September 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper investigates the possibility of detecting emergency voice. We adopt wavelet transformation for pre-processing the sounds, and we use a neural network for recognizing abnormalities.View full abstractDownload PDF (790K) -
Toyonori NISHIMATSU, Hiroyasu KOSHIMIZU, Eiji TOBA1994 Volume 30 Issue 9 Pages 1126-1128
Published: September 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIt is investigated and discussed how the defects on the inner peripheral surface of bearing should be imaged and detected by the computer image processing technique with CCD camera and the experimental cone mirror. The binarization was done about the digital image by means of a simple thresholding operation and the defects on the inner peripheral surface could be detected clearly. From the result of single regression analysis between the sensory value about the defect's grade by inspectors and the measured defect's area was examined, there was a good agreement between the values calculated by this regression equation and the sensory value by inspectors.View full abstractDownload PDF (948K) -
Takehiro MORI, Hideki KOKAME1994 Volume 30 Issue 9 Pages 1129-1131
Published: September 30, 1994
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSGiven a nominal Schur matrix, a simple method is proposed to estimate Schur-stability hypercube in matrix entry space around the nominal point. This shows a parallelism with an already existing result for Hurwitz-stability hypercube.View full abstractDownload PDF (386K)
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