共查询到17条相似文献，搜索用时 0 毫秒
1.
Hiroyuki Okuda Soichiro Hayakawa Tatsuya Suzuki Nuio Tsuchida 《Electrical Engineering in Japan》2011,177(1):55-64
Recently, the demand for man–machine cooperative systems has been growing in many industrial fields, particularly in cell production and in flexible manufacturing systems. In the design of man–machine cooperative systems, the characteristics of human behavior must be considered. This paper presents a new design strategy for a switched assist controller for a man–machine cooperative positioning task that takes into consideration a human behavior model based on a continuous/discrete hybrid dynamical system. First, the human behavior model is identified as a piecewise ARX model using k‐means clustering and a support vector machine. Second, the switched assist system is designed as a switched impedance controller based on the identified hybrid human behavior model with optimization. The optimization was solved by performing a forward calculation of the closed loop response of the human behavior model and controller with a criterion reflecting the task time and the force effort. The results show that one can find the optimal parameters for a switched impedance controller. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 177(1): 55–64, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.20932 相似文献
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This paper describes a novel straight and circular road driving control scheme for electric power‐assisted wheelchairs. “Electric power‐assisted wheelchair” which assists the driving force by electric motors is expected to be widely used as a mobility support system for elderly people and disabled people, however, the performance of straight and circular road driving must be further improved because the two wheels drive independently. This paper proposes a novel driving control scheme based on fuzzy algorithm to realize stable and reliable driving on straight and circular roads. The suitable assisted torque of the right and left wheels is determined by fuzzy algorithm based on the posture angular velocity of the wheelchair and the human input torque proportion of the right and left wheels. Some experiments on the practical roads show the effectiveness of the proposed control system. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 170(1): 36–44, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20846 相似文献
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Dependence of frequency on amplitude and control bias is considered for the cross‐coupled voltage‐controlled oscillator. Closed form expressions are derived for frequency of oscillation as a function of amplitude, for positive and negative control bias voltages. Theory of nonlinear ordinary differential equations is utilized to show that the capacitance–voltage relation is the main cause of frequency shift with amplitude. Furthermore, the case of small amplitudes relative to control voltage is analyzed, and a closed form expression is derived for dependence of frequency on amplitude. This relation is then verified using the concept of effective capacitance. The effective capacitance approach is also used to extend the analysis to large voltage swings. Dependence of frequency on tuner control voltage is calculated for both bias polarities. Implications of the aforementioned equations for voltage‐controlled oscillator performance are discussed. Numerical calculations and simulations are used to compare and verify the closed form equations, showing good agreement. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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带磁放大器调整多路输出直–直变换器环路互扰 总被引：1，自引：0，他引：1
带磁放大器后级调整多路输出直–直变换器采用峰值电流控制时,若采样原边电流控制,则磁放大器回路会被引入不规则脉动电流,使得主环路与磁放大器环路相互耦合,环路的相互作用会导致主辅路输出电压振荡。建立磁放大器环路及系统级小信号模型,分析环路互扰现象的机理,指出环路互扰现象实质上是负载交叉调整率恶化时的另一种表达方式,并基于交错输出阻抗分析提出相应解决方案,即通过提高主环路外环开环增益或采用斜坡补偿方式,能够有效解决环路互扰现象。 相似文献
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《IEEJ Transactions on Electrical and Electronic Engineering》2018,13(5):748-756
Scheduling problems with resource allocation have become of increasing interest in the academic and industrial areas in recent years. This study investigates parallel machine scheduling with dynamic resource allocation under the objective of minimizing the makespan, where the processing of jobs needs an additional resource that can be assigned and reassigned among all jobs, and the processing time of jobs is a function of the amount of allocated resources. Four decisions must be made in a schedule, namely job assignment, job sequence, resource allocation and jobs' starting time. In order to solve it efficiently, a master–slave genetic algorithm is proposed to determine the decisions of job assignment, job sequence and resource allocation, and a greedy heuristic rule is designed to determine the jobs' starting time. To examine the performance of the proposed algorithm, simulation experiments are carried out on a set of instances, and similar existing algorithms and the standard genetic algorithm are chosen as for comparison. The experimental results show that the proposed algorithm is a promising optimizer in solving the investigated problem. © 2018 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
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Kyle Fricke Robert Sobot Anestis Dounavis 《International Journal of Circuit Theory and Applications》2014,42(2):195-208
We present an analogue signal‐processing circuit suitable for applications in a portable, wearable, non‐invasive electrooculogram‐based human–computer interface. Behavioural model and preliminary experimental results confirm that the proposed circuit, while operating in real time, correctly detects and decodes signals generated by the subject's eye movements. The total power consumption is measured at 145 mW (excluding the RF link) with a 3 V power supply voltage, and the unit size is approximately 5 cm × 3 cm printed circuit board. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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We have developed a novel evaluation technique of the deterioration degree of insulators for breakers using a chemical analysis and the Mahalanobis–Taguchi (MT) method. It is possible to evaluate the deterioration degree with great accuracy and nondestructively on‐site by this technique without the effect of humidity and external noise such as electromagnetic waves. The mechanism of the insulator's surface resistivity reduction was clarified, and it was found that the deterioration degree of insulators could be evaluated by this technique because a linear relationship existed between the results judged by the MT method and the actual measurement results for the surface resistivity. In comparison to electrical methods, such as partial electric discharge and megohmmeters, the evaluation accuracy has been improved by three digits and the range of the deterioration degree that could be evaluated was expanded by seven digits. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 168(1): 11–20, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20849 相似文献
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Despite substantial progress of research efforts in the field of photovoltaic (PV) power generation, some serious problems remain to be solved, including a fairly low energy generated by PV systems in comparison to the expected output, and a broad spread of output values among individual PV systems. The expected level of generated energy is usually evaluated by means of such coefficients as “the performance ratio” which is obtained as the energy actually generated by a PV array over a period of 1 year divided by the calculated output over the same period. However, this method has some limitations, such as the necessity to continuously perform data measurements over a long time, difficulties in the examination of factors reducing the level of the generated energy or improving the system efficiency, and so on. In this study, the authors propose a new method of accurate evaluation of the generated energy. The authors also examined a method for classifying the losses caused by the rise of the PV cell temperature and presented a method of data measurements over a short time period. The proposed method can also be applied to the classification and analysis of losses occurring at the time of the MPPT operation of the system (Pmax operation). © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 154(4): 24–33, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20222 相似文献
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Naoki Wake Masaaki Fukumoto Hirokazu Takahashi Katsushi Ikeuchi 《IEEJ Transactions on Electrical and Electronic Engineering》2019,14(12):1815-1822
Speech interfaces for household robots utilizing third‐party automatic speech recognition (ASR) services face the challenge of overcoming stationary ego‐noise that decreases ASR accuracy. Previous studies on signal processing have proposed numerous noise reduction methods that increase the signal‐to‐noise ratio of speech audio and subjective speech clarity. However, severe limitations on the cost of hardware of household robots and the use of closed ‘black box’ ASR services require us to re‐examine the efficacy of noise reduction methods in this context. Here we compare the effect of several basic noise filters on the performance of ASR services when speech sounds include the stationary ego‐noise of a humanoid Pepper robot. The result revealed that a spectrum subtraction filter improves the accuracy of ASR services best. We also demonstrate that the filter improves ASR performance on an actual Pepper robot system. This study not only provides practical knowledge on the selection of noise filters for a robot system but also discusses further improvements to the listening capabilities of the robot utilizing ASR. © 2019 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
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Qiaoshan Li Bingyi Zhang Aimin Liu 《IEEJ Transactions on Electrical and Electronic Engineering》2020,15(10):1414-1422
Combining Schwarz–Christoffel transformation, magnetic field reconstruction method, and Maxwell stress tensor method, the calculation model of cogging torque of a dual‐stator axial flux permanent magnet machine is established. The end effect and slotting effect are both been taken into account. The results are verified by finite element method. And with the proposed method, calculation time can be significantly reduced compared with finite element method. Three measures to reduce the cogging torque of dual‐stator axial flux permanent magnet machines are discussed based on which the cogging torque is optimized by genetic algorithm. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. 相似文献
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Yuichi Tamura Ikuya Sato Hisao Kubota Hisayoshi Ohta Yoichi Hori 《Electrical Engineering in Japan》2003,145(4):78-87
The objective of this investigation is to stabilize a sensorless vector control system of induction motors by means of an adaptive observer in regenerating mode at very low speed. The adaptive observer gain is designed by means of the Routh–Hurwitz criterion. It is verified by simulation and experiment that the proposed system is stable. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 145(4): 78–87, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10202 相似文献
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Tinghua Wang Xiaoqiang Tu 《IEEJ Transactions on Electrical and Electronic Engineering》2019,14(5):760-767
Multiple kernel learning (MKL) is a principled way for kernel fusion for various learning tasks such as classification, clustering, and dimensionality reduction. The least absolute shrinkage and selection operator (Lasso) allows computationally efficient feature selection based on the linear dependence between input features and output values. In this paper, we develop a novel MKL model based on a nonlinear Lasso, that is, the Hilbert–Schmidt independence criterion (HSIC) Lasso. In the proposed model, we first propose the HSIC Lasso‐based MKL formulation, which has a clear statistical interpretation that minimum redundant kernels with maximum dependence on output labels are found and combined, and also that the global optimal solution can be computed efficiently by solving a Lasso optimization problem. After the optimal kernel is obtained, the support vector machine (SVM) is used to select the prediction hypothesis. It is evident that the proposed MKL is a two‐stage kernel learning approach. Extensive experiments on real‐world datasets from the UCI benchmark repository validate the superiority of the proposed model in terms of prediction accuracy. © 2018 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
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Suwoong Lee Hidetaka Nozawa Jae‐Il Kim Kenji Inoue 《IEEJ Transactions on Electrical and Electronic Engineering》2013,8(5):529-534
Physical human–robot interaction (PHRI) is an essential concept for human‐cooperative robots (HCRs). Because the force control for PHRI is based on the contact force between a human and an HCR, it is very important to collect the force data accurately. Furthermore, soft contact during force sensing is also necessary for PHRI for safety and security. As a challenge in force sensing for PHRI using a soft material, we aim to develop in this study a novel force‐sensing device based on an air cushion. First, the physical model of the air cushion is represented by an air cylinder with a piston, which is subject to constraint by nonlinear elasticity. Second, the elastic properties of the air cushion are examined under the assumption that it can be formulated as a function of pneumatic pressure and the contact area with a human. The force applied to the air cushion is estimated on the basis of the physical model and compared to the actual force data in the fundamental experiments. Force is successfully estimated using the proposed physical model, and the advantages of the air‐cushion‐based force‐sensing device (ACFSD) are verified through these fundamental experiments. © 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
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Anil Kumar Vuppala K. Sreenivasa Rao Saswat Chakrabarti 《International Journal of Adaptive Control and Signal Processing》2012,26(4):333-349
In this paper, we proposed a method for improving the recognition performance of 145 prominent consonant–vowel (CV) units in Indian languages for low bit‐rate coded speech. Proposed CV recognition method is carried out in two levels to reduce the similarity among a large number of CV classes. In the first level, vowel category of CV unit will be recognized, and in the second level, consonant category will be recognized. At each level of the proposed method, complementary evidences from support vector machine and hidden Markov models are combined to enhance the recognition performance. Effectiveness of the proposed two‐level CV recognition method is demonstrated by performing the recognition of isolated CV units and CV units collected from the Telugu broadcast news database. In this work, vowel onset point (VOP) is used as an anchor point for extracting accurate features from the CV unit. Therefore, a method is proposed for accurate detection of VOP in clean and coded speech. The proposed VOP detection method is based on the spectral energy in 500–2500 Hz frequency band of the speech segments present in the glottal closure region. Speech coders considered in this work are GSM full rate (ETSI 06.10), CELP (FS‐1016), and MELP (TI 2.4 kbps). Significant improvement in CV recognition performance is achieved using the proposed two‐level method compared with the existing methods under both clean and coded conditions. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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Hong Lei, Lian‐Ze Wang and Zi‐Niu Wu presented new simple and convenient solutions of the magnetic field for an arbitrary geometry coil with rectangular cross section. They treated two types of basic forms: the trapezoidal prism segment and curved prism segment. The curved prism segment has been divided into a series of small trapezoidal prism segments with the same cross section and its magnetic field is a vector sum of the individual fields created by each small trapezoidal prism conductor. For one trapezoidal prism conductor the magnetic field is obtained by 1‐D integrals using Romberg numerical integration. In this paper, we give a completely analytical solution of these 1‐D integrals that considerably saves the computational time especially in the computation of the magnetic field nearby the conductor surface, at the conductor surface and inside the conductor. From obtained analytical expressions the treatment of singularities can be easily done. Also, we tested four types of numerical integration (Gaussian, Romberg, Simpson and Lobatto) to find the most convenient singularity treatment of 1‐D integrals. These obtained results are compared with those obtained analytically so that one can understand the advantage of the proposed approach. The paper points out on the accuracy and the computational cost. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献