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Volume 121, Issue 8
Displaying 1-13 of 13 articles from this issue
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Takehiko Takahashi2001 Volume 121 Issue 8 Pages 829-834
Published: August 01, 2001
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSDownload PDF (1669K) -
Toshihiro Fukuyama, Toshiji Kato2001 Volume 121 Issue 8 Pages 835-840
Published: August 01, 2001
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSThere is a tolerance between a designed and an actual characteristics when there are circuit parameter variations in a designed circuit. It is necessary to develop a tolerance analysis method which computes the tolerance region under circuit parameter variations. Interval mathematics is one of these analysis methods. However no practical method has been reported for transient or steady-state analysis because they are initial value or boundary value problems. This paper proposes an alternative method which efficiently computes a tolerance region with a parameter polynomial approximately and practically by using the Taylor series expansion with a higher order sensitivity analysis method.View full abstractDownload PDF (1268K) -
Mineyo Morimoto, Ikuro Morita2001 Volume 121 Issue 8 Pages 841-847
Published: August 01, 2001
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSRecent developments in induction motors have been moving forward reducing the size and weight of motors. Furthermore for these motors, it demands for much quieter operating conditions to meet environment. Various design methods have been applied to reduce the vibration and acoustic noise of induction motors. One method is to make the slot pitches of the cage rotor unequal, to avoid the resonance with the natural frequencies of the stator frame. In this paper, our purpose is to create guidelines for reducing noise. As the first step for this purpose, we developed a method to analyze the voltage and torque equations of an induction motor with an unequal slot pitched cage rotor and discussed the characteristics from the analyzed currents.View full abstractDownload PDF (1332K) -
Satoshi Yura, Takuya Kamano, Takashi Yasuno, Takayuki Suzuki, Hironobu ...2001 Volume 121 Issue 8 Pages 848-854
Published: August 01, 2001
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSIn this paper, we describe swing up and stability control of inverted pendulum with an inertia rotor. To realize the smooth swing up motion of the inverted pendulum, the energy method is introduced. Then, the speed of the inertia rotor is controlled so that the energy of the pendulum increases. When the pendulum is inverted, the control method is changed to the stability control with the sliding mode. The sliding mode controller is effective to stabilize the pendulum because the controller has robustness for the modeling error. The design of both swing up and stability controllers are shown. The responses of the pendulum using the both controllers are measured. Experimental results demonstrate that the proposed controllers have effectiveness and robustness.View full abstractDownload PDF (1298K) -
Katsuji Shinohara, Eiichi Sakasegawa2001 Volume 121 Issue 8 Pages 855-861
Published: August 01, 2001
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSThree level inverter has several advantages of large capacity, large voltage and low current waveform distortion. However, there is an important problem of neutral point potential variation in three level inverter. The variation causes an unbalance in the DC link voltage levels and current waveform distortion. In this paper, we propose a new method to control the neutral point potential. First, the neutral point potential variation in three level inverter for permanent magnet synchronous motor drive is analyzed by state variable method and is calculated on the basis of the analytic results. Second, using the estimated value, proposed compensation for the variation can be done. Third, analytic and experimental results of proposed method are compared with the results of feedforward compensation by simply adjusting the vector output intervals.View full abstractDownload PDF (956K) -
Itani NAGAYAMA, Morikazu NAKAMURA, Tsuyoshi YAMASHIRO2001 Volume 121 Issue 8 Pages 862-868
Published: August 01, 2001
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSThis paper describes a new approach for competitive learning network and its application to diagnosis of breast cancer in medical pattern recognition. Conventional competitive learning such as RCE network proposed by Cooper et. al. has a good performance caused by the faster learnability than popular steepest descent methods. However, the RCE network has a shortcoming with its decision making process. Thus, we introduce the confidential voting process in order to avoid the ambiguous decision making in the RCE network. Generally speaking, despite of great deal of public awareness, breast cancer continues to be one of the most common cancer diseases. Therefore, if we can find an efficient method to diagnose the cancer with computer technology, the more efficient early detection can be performed. We first discuss some essential issues to be considered in medical aspects of cancer diagnosis. Experimental results by using the proposed competitive network with confidential voting are also described. The good performance of the new competitive learning approach is shown.View full abstractDownload PDF (1363K) -
Kouki Matsuse, Shotaro Taniguchi, Tatsuya Yoshizumi, Kazushige Namiki2001 Volume 121 Issue 8 Pages 869-878
Published: August 01, 2001
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSThis paper proposes a speed-sensorless vector control method for an induction motor operating at high efficiency and high response, in which core loss is taken into account, and discusses the system's performance. The proposed vector control system consists of a speed-adaptive rotor-flux observer which takes core loss into account and employs a direct-field-oriented control scheme which compensates for the influence of core loss. On the basis of simulation and experimental results, we show that the proposed system can estimate motor speed even when the rotor flux is changed.View full abstractDownload PDF (1306K) -
Mitsuo Hirata, Donghao Tang, Kenzo Nonami, Hideaki Ogawa, Yoshihiro Ta ...2001 Volume 121 Issue 8 Pages 879-886
Published: August 01, 2001
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSThe piezoelectric actuator has high-speed response in comparison with the electro-magnetic actuator. However it is not easy to achieve the both of high-speed and high-precision response, because the piezoelectric-element has nonlinear property such as hysteresis effect. So the feedback control must be required to achieve good performance.
In this paper, we develop a new control design method to achieve the both of high-speed and high-precision response for piezoelectric actuator by using the discrete-time H∞ control method and the two-degree-of-freedom control scheme. The effectiveness of our proposed method has been shown by the simulation and the experimental result. The most important contribution of our study is that our method can be directly used to the commercial machine.View full abstractDownload PDF (2081K) -
Shoji Fujisawa2001 Volume 121 Issue 8 Pages 887-893
Published: August 01, 2001
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSLinear encoders are important and indispensable components of linear motor drive systems which have been rapidly introduced into the industry in recent years.
Nowadays the performance of linear motor drive systems is greatly influenced by the performance of linear encoders. This means that linear encoders are important parts to educe high performance of linear motor drive systems. And it is considered that linear encoders should be studied continuously to improve their performance.
In this paper a newly developed linear encoder for linear motors and its utility are introduced. In spite of a small size and a simple structure, this linear encoder is able to combine high resolution with high response and has the capacity of the minimum resolution 0.25μm and the maximum speed 100m/s or more.View full abstractDownload PDF (2414K) -
Djoko Purwanto, Toshiyuki Murakami, Kouhei Ohnishi2001 Volume 121 Issue 8 Pages 894-901
Published: August 01, 2001
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSThis paper presents a control system to move the manipulator smoothly in linear path between two designated POSE (position and orientation). Two independent commands, the POSE command and the velocity command, are applied as input of position-based and velocity-based control, respectively. The step function of POSE command describes directly the desired change of manipulator's POSE from a source to a destination POSE. The velocity command determines the desired manipulator velocity, and contributes directly to the smoothness of movement. To obtain a linear path, the trajectories lying between the source and destination POSE are controlled to change in linear way by employing a weighting function. Experiments conducted on a 3-links serial planar manipulator demonstrated the performance of the proposed controller. As addition, taking the merits of the proposed manipulator control system, a visual tracking system is realized and demonstrated via experiments.View full abstractDownload PDF (3526K) -
Yoshihiko Kinpara, Shinji Doki, Shigeru Okuma2001 Volume 121 Issue 8 Pages 902-907
Published: August 01, 2001
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSIn recent years, many vector control methods with a flux observer for the induction motors have been developed. In these methods, torque control characteristics deteriorate when an induction motor is driven at low speeds with resistance deviations.
In this paper, robust flux observer with optimal feedback gain is proposed in which resistance deviations assume to be system noise, and error equation is derived. Proposed method is shown to be feasible with experimental results.View full abstractDownload PDF (2927K) -
The Relation between Depth of Rotor Bars and Load InertiaKazumi Kurihara, Yuichiro Baba, Tohru Nakada, Tomotsugu Kubota, Hong W ...2001 Volume 121 Issue 8 Pages 908-909
Published: August 01, 2001
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSThis paper describes the effects which depth of rotor bars in self-starting permanent magnet synchronous motor has on starting and steady-state performance characteristics. In particular, the maximum load inertia versus depth of rotor bars when the motor synchronizes becomes clear by using the time-stepped finite element technique.View full abstractDownload PDF (181K) -
Satoshi Hamada, Mutsuo Nakaoka2001 Volume 121 Issue 8 Pages 910-911
Published: August 01, 2001
Released on J-STAGE: December 19, 2008
JOURNAL FREE ACCESSA new interleaved two switch forward soft-switching PWM DC-DC converter topology is presented. The proposed converter is developed to minimize circulating current with no additional auxiliary circuits. The principle of operation is illustrated. In addition, to verify the performances, key experiments are built and tested with a 500W, 100kHz breadboard.View full abstractDownload PDF (164K)
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