IEEE Transactions on Industrial Electronics

Volume 52, Number 6, Dec 2005 Access to the journal on IEEE XPLORE IE Transactions Home Page

Special Section Papers on Human-Robot Interface

52.6.1	H. Iwata, S. Sugano, "Human-robot-contact-state identification based on tactile recognition," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1468- 1477, Dec 2005. Abstract Link Full Text Abstract: In this paper, we propose a method for designing an identification system for human-robot contact states based on tactile recognition. The following ideas are incorporated: experimentation for human-robot contact, verbalization of contact states, extraction of characteristic parameters from acquired tactile information, quantification of the recipient's tactile recognition incorporating its redundancy (identification confusability among contact states), evaluation of the identification confusability with a new criterion, and identification of contact states based on the received tactile stimulation. The proposed method allows a robot to quantify tactile recognition of a human (recipient) touched by other people (touch initiator), in which the verbal response by the recipient is matched with tactile stimulation acquired during physical contact utilizing a tactile interface. In addition, the method enables a robot that comes into contact with a human to identify contact states nearly similar to that of the recipient, based on the features of the received tactile stimulation. At this point, the reproduction of the identification confusability of the recipient's tactile recognition is also accomplished by using a neural network called modified counterpropagation (MCP). Once a tactile stimulation is induced on the robot body, the probability of corresponding contact states is calculated and outputted by the system, based on the degree of similarity of the characteristics between the newly received and previously stored tactile stimulation. Experimental results indicate that the constructed system allows a successful quantification of the recipient's contact-state recognition incorporating the identification confusability and the accomplishment of a high level of accuracy in contact-state identification. These results confirm that the proposed method is useful for identifying human-robot contact states based on tactile recognition.
52.6.2	A. Chatterjee, K. Pulasinghe, K. Watanabe, K. Izumi, "A particle-swarm-optimized fuzzy-neural network for voice-controlled robot systems," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1478- 1489, Dec 2005. Abstract Link Full Text Abstract: This paper shows the possible development of particle swarm optimization (PSO)-based fuzzy-neural networks (FNNs) that can be employed as an important building block in real robot systems, controlled by voice-based commands. The PSO is employed to train the FNNs that can accurately output the crisp control signals for the robot systems, based on fuzzy linguistic spoken language commands, issued by a user. The FNN is also trained to capture the user-spoken directive in the context of the present performance of the robot system. Hidden Markov model (HMM)-based automatic speech recognizers (ASRs) are developed, as part of the entire system, so that the system can identify important user directives from the running utterances. The system has been successfully employed in two real-life situations, namely: 1) for navigation of a mobile robot; and 2) for motion control of a redundant manipulator.
52.6.3	Yoon Sang Kim, Byung Seok Soh, Sang-Goog Lee, "A new wearable input device: SCURRY," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1490- 1499, Dec 2005. Abstract Link Full Text Abstract: A new wearable input device named SCURRY, developed by the Samsung Advanced Institute of Technology, is introduced in this paper. Based on inertial sensors, this device allows a human operator to select a specified character, an event, or an operation as the input he/she wants spatially through both hand motion and finger clicking. It is a glovelike device, which can be worn on the human hand, composed of a base module, including one controller and two angular-velocity sensors (gyroscopes) on the back of the hand, and four ring-type modules (rings), including two-axis acceleration sensors (accelerometers) on four fingers. The base and the ring modules are integrated modules containing sensors, a transceiver or receiver for communication, and a microcontroller, which makes the device compact and light. The two gyroscopes embedded in the base module have a role in detecting the direction (up, down, right, and left) of the hand motion, and the accelerometers have a role in detecting finger motion generated by finger clicking. An algorithm for the exact finger-click recognition composed of three parts (feature extraction, valid-click discrimination, and crosstalk avoidance) is proposed to improve the recognition performance of finger clicking on SCURRY. The experimental results and discussions are presented. SCURRY can be used as a wearable mouse spatially, by allowing any three fingers to be operated as the left, middle, and right mouse buttons, and in a similar manner, as a wearable keyboard, as it allows a human operator to point and select any character, event, or operation by his hand motion and finger clicking.
52.6.4	Z.Z. Bien, Kwang-Hyun Park, Jin-Woo Jung, Jun-Hyeong Do, "Intention reading is essential in human-friendly interfaces for the elderly and the handicapped," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1500- 1505, Dec 2005. Abstract Link Full Text Abstract: Some major issues of human-friendly man-machine interaction/interfaces in an intelligent residential system are dealt with to cope with increasing needs of the elderly and the handicapped for a higher level of living conditions. Specifically, the existing systems in this area are first examined and the inadequacy of some current remote-control interfaces for the elderly/handicapped is pointed out. Then, some intention-reading techniques are introduced for the elderly and/or the physically handicapped, for easier and more convenient use of machines and engineering systems.
52.6.5	R. Marin, P.J. Sanz, P. Nebot, R. Wirz, "A multimodal interface to control a robot arm via the web: a case study on remote programming," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1506- 1520, Dec 2005. Abstract Link Full Text Abstract: In this paper, we present the user interface and the system architecture of an Internet-based telelaboratory, which allows researchers and students to remotely control and program two educational online robots. In fact, the challenge has been to demonstrate that remote programming combined with an advanced multimedia user interface for remote control is very suitable, flexible, and profitable for the design of a telelaboratory. The user interface has been designed by using techniques based on augmented reality and nonimmersive virtual reality, which enhance the way operators get/put information from/to the robotic scenario. Moreover, the user interface provides the possibility of letting the operator manipulate the remote environment by using multiple ways of interaction (i.e., from the simplification of the natural language to low-level remote programming). In fact, the paper focuses on the lowest level of interaction between the operator and the robot, which is remote programming. As explained in the paper, the system architecture permits any external program (i.e., remote experiment, speech-recognition module, etc.) to have access to almost every feature of the telelaboratory (e.g., cameras, object recognition, robot control, etc.). The system validation was performed by letting 40 Ph.D. students within the "European Robotics Research Network Summer School on Internet and Online Robots for Telemanipulation" workshop (Benica/spl grave/ssim, Spain, 2003) program several telemanipulation experiments with the telelaboratory. Some of these experiments are shown and explained in detail. Finally, the paper focuses on the analysis of the network performance for the proposed architecture (i.e., time delay). In fact, several configurations are tested through various networking protocols (i.e., Remote Method Invocation, Transmission Control Protocol/IP, User Datagram Protocol/IP). Results show the real possibilities offered by these remote-programming techniques, in order to design experiments intended to be performed from both home and the campus.
52.6.6	Dong To Nguyen, Sang-Rok Oh, Bum-Jae You, "A framework for Internet-based interaction of humans, robots, and responsive environments using agent technology," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1521- 1529, Dec 2005. Abstract Link Full Text Abstract: In this paper, a systematic framework for Internet-based interaction of humans, robots, and environments is proposed by using agent technology. The framework is validated by proposing the concept of slave agents, a virtual directory facilitator (VDF) to control the slave agents, and a responsive multiagent environment. It creates a robot control system in which humans, robots, and environments can interact without much prior knowledge. Finally, a number of experiments have been conducted successfully by adopting JadeLeap middleware and Foundation for Intelligent Physical Agents (FIPA) standard under the environment composed of a personal digital assistant (PDA), a home service robot-intelligent, sweeping security assistant companion (ISSAC), and a video camera network. Experimental results show that the proposed framework increases the availability of whole system, decreases the time for Internet connection of robots and user devices such as PDAs, and provides the responsiveness of environments.
52.6.7	B. Jensen, N. Tomatis, L. Octor, A. Drygajlo, R. Siegwart, "Robots meet Humans-interaction in public spaces," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1530- 1546, Dec 2005. Abstract Link Full Text Abstract: This paper presents experiences from Robotics, a long-term project at the Swiss National Exposition Expo.02, where mobile robots served as tour guides. It includes a description of the design and implementation of the robot and addresses reliability and safety aspects, which are important when operating robots in public spaces. It also presents an assessment of human-robot interaction during the exhibition. In order to understand the objectives of interaction, the exhibition itself is described. This includes details of how the human-robot interaction capabilities of the robots have evolved over a 5-month period. Requirements for the robotic system are explained, and it is shown how the design goals of reliability and safe operability, and effective interaction, were achieved through appropriate choice of hardware and software, and the inclusion of redundant features. The modalities of the robot system with interactive functions are presented in detail. Perceptive elements (motion detection, face tracking, speech recognition, buttons) are distinguished from expressive ones (robotic face, speech synthesis, colored button lights). An approach for combining stage-play and reactive scenarios is presented. The authors also explain how an emotional state machine was used to create convincing robot expressions. Experimental results, both technical and those based on a visitor survey, as well as a qualitative discussion, give a detailed report on the authors' experiences in this project. Power Electronics
52.6.8	M. Borage, S. Tiwari, S. Kotaiah, "Analysis and design of an LCL-T resonant converter as a constant-current power supply," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1547- 1554, Dec 2005. Abstract Link Full Text Abstract: An LCL-T resonant converter (LCL-T RC) is shown to behave as a current source when operated at resonant frequency. A detailed analysis of the LCL-T RC for this property is presented. Closed-form expressions for converter gain, component stresses, and the condition for converter design optimized for minimum size of resonant network is derived. A design procedure is illustrated with a prototype 200-W 20-A current-source power supply and experimental results are presented. The LCL-T RC as a current source offers many advantages such as easy parallel operation and low circulating currents at light load. Additionally, with appropriate phase shift in paralleled modules, the peak-peak ripple in output current is reduced and the ripple frequency is increased, reducing filtering requirements. The leakage inductance of a transformer can be advantageously integrated into the resonant network. These merits make the topology applicable in various applications such as magnet power supply, capacitor charging power supply, laser diode drivers, etc.
52.6.9	Xiaopeng Wang, Ruoping Yao, Fangquan Rao, "Subsystem-interaction restraint in the two-stage DC distributed power systems with decoupling-controlled-integration structure," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1555- 1563, Dec 2005. Abstract Link Full Text Abstract: Subsystem interaction is an important issue in the two-stage dc distributed power system (DPS) featuring many individually regulated subsystems well designed in their standalone mode. This paper investigates not only the mechanism of realizing the subsystem-interaction restraint with the decoupling-controlled-integration (DI) structure, but also the improvement of DPS's small-signal stability and the regulated load converter's input impedance consequent on the subsystem-interaction restraint dependent on DI. DI is different from the conventional integration (CI) structure in that the so-called decoupling operators are developed to map the regulation signal of a source subsystem into the regulation loops of load subsystems. Through classifying the interaction loops in DPS into static and dynamic ones, it is revealed that DI is efficient in eliminating the dominant dynamic-interaction terms in the quasi-static state. Furthermore, with the aid of a three-step impedance criterion, two additional stability-enhancement terms in DPS with DI are picked up. The existence of the stability-enhancement term interprets why an original unstable DPS with CI is possible to become a stable one, provided that the subsystem interaction is restrained through substituting CI with DI. Moreover, as DI is able to improve the low-frequency input impedance character of a tightly regulated load converter, that is, to decrease the negative resistance value or even transform it to a positive one, the possibility of negative impedance instability is definitely decreased.
52.6.10	Yie-Tone Chen, Wen-Ming Lin, Yu-Hsuan Liu, "Analysis and design of a dimmable electronic ballast controlled by a switch-controlled capacitor," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1564- 1572, Dec 2005. Abstract Link Full Text Abstract: This paper presents the related principle and analysis of the dimmable electronic ballast controlled by the switch-controlled capacitor (SCC). A Fourier-series expansion is used to derive the operational principle of the zero-voltage-switching Class-D series-parallel-load-resonant dimmable electronic ballast regulated by the SCC. By the adaptation of the SCC, the lightness of the system can be adjusted, while the operation frequency of the Class-D converter can be kept constant. The dimmable effect controlled by the variable SCC is examined. The analytical results are verified by simulations and experiments. Furthermore, the design considerations for the dimmable electronic ballast with SCC control are also presented in this paper.
52.6.11	Sung-Jin Choi, Kyu-Chan Lee, Bo Hyung Cho, "Design of fluorescent lamp ballast with PFC using a power piezoelectric transformer," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1573- 1581, Dec 2005. Abstract Link Full Text Abstract: An investigation of a high-power piezoelectric transformer (PT) as a potential component for a fluorescent lamp (FL) ballast with power factor correction (PFC) is discussed. The attractiveness of the PT is primarily the simplicity of the resulting circuit, and it is easy to be produced in mass with a low cost. A single-stage charge-pump PFC ballast using a PT is proposed. The proposed ballast circuit improved the drawbacks of the conventional voltage-source charge-pump PFC (VS-CPPFC) scheme. Empirical PT modeling based on power level excitation is performed to design the proposed circuit, and the experimental and simulation results are provided to verify theoretical analysis.
52.6.12	J. Pou, R. Pindado, D. Boroyevich, P. Rodriguez, "Evaluation of the low-frequency neutral-point voltage oscillations in the three-level inverter," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1582- 1588, Dec 2005. Abstract Link Full Text Abstract: The nearest vectors to the reference vector are commonly used in space-vector modulation (SVM) strategies. The main advantages of these modulation strategies are the low switching frequencies of the devices, the good output voltage spectra, and the low electromagnetic interference. However, when these techniques are applied to the three-level neutral-point (NP)-clamped inverter, low-frequency oscillations appear in the NP voltage for some operating conditions. As a result, the value of the dc-link capacitors must be increased in order to attenuate such oscillations. In this paper, these amplitudes are quantified for two modulation strategies that use nearest vectors to the reference vector. Owing to the nondimensional variables used in the analysis, the information provided will help for the calculation of the dc-link capacitors in a given specific application. Simulated and experimental examples are presented.
52.6.13	J.E. Espinoza, J.R. Espinoza, L.A. Moran, "A systematic controller-design approach for neutral-point-clamped three-level inverters," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1589- 1599, Dec 2005. Abstract Link Full Text Abstract: This paper proposes a simple linear feedback-based control technique that ensures zero-neutral-point (NP) potential in three-level voltage-source inverters. The technique works even under dynamic load conditions and enables the decoupled control of the direct and in-quadrature load currents. The technique is based on the relative-gain-array (RGA) approach, which has been successfully used in the control of chemical-engineering processes. The resulting scheme allows the use of outer control loops to set the direct and in-quadrature load currents as required for the specific application (e.g., adjustable speed drives). Experimental results prove the theoretical considerations and show the simplicity of the proposed control scheme.
52.6.14	Feel-Soon Kang, Sung-Jun Park, Man Hyung Lee, Cheul-U Kim, "An efficient multilevel-synthesis approach and its application to a 27-level inverter," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1600- 1606, Dec 2005. Abstract Link Full Text Abstract: This paper presents an efficient multilevel-synthesis scheme and its application to a 27-level inverter. In the proposed multilevel scheme, this can be realized by an array of switching devices composing full-bridge inverter modules and proper mixing of each transformer terminal voltage. The most different aspect, compared to the conventional approach, in the synthesis of the multilevel output waveform is the utilization of a combination of transformers rather than the accumulation of capacitor voltage sources. A 27-level inverter consists of three full-bridge modules and their corresponding transformers. Quasi-sinusoidal voltage waves can be generated from a suitable selection of the turns ratio of the transformer. The validity of the proposed system is verified by computer-aided simulation and experimental results using a 500-W prototype, which can generate a 110-V ac output voltage from a 12-V dc input.
52.6.15	S. Muller, U. Ammann, S. Rees, "New time-discrete modulation scheme for matrix converters," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1607- 1615, Dec 2005. Abstract Link Full Text Abstract: While the known modulation strategies for matrix converters are based on pulsewidth modulation (PWM)-or vector modulation-this paper presents a novel time-discrete modulation method based on real-time prediction calculation to select the switching states. The decision about which switching state is to be set for the following sampling period is made by the use of a predictive quality function. Using this approach, unity displacement factor is seen at the supply side with minimum line current distortion while the load currents follow their reference values with good accuracy. The quality function is derived from a mathematical model of the matrix converter and the controlled system. Measurements taken on a model plant, consisting of a matrix converter and a standard induction machine with a rated output power of 11 kW, show that the matrix converter, equipped with the control method presented here, offers advantages over systems with conventional frequency converters, especially in terms of the input current distortion.
52.6.16	M. Salo, H. Tuusa, "A new control system with a control delay compensation for a current-source active power filter," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1616- 1624, Dec 2005. Abstract Link Full Text Abstract: In this paper, a new control system for the current-source active power filter is presented. The harmonic current compensation is realized using combined feedforward control of the load currents and closed-loop control of the supply currents. The control system includes a simple method for compensating the sampling and calculation delays of the digital control system. The compensation in the proposed method is achieved using the regular LC filter of the active power filter as an energy storage for load currents, and no additional components is needed in the main circuit. Furthermore, the calculation power demand of the compensation method is very low and is, therefore, suitable for single-chip microcontroller implementations. The proposed control system is realized using a 32-bit Motorola MPC555 microcontroller. The simulation and experimental results show effective filtering performance also for higher order harmonics of the distorted load currents. Drive Control
52.6.17	I. Husain, S.A. Hossain, "Modeling, Simulation, and control of switched reluctance motor drives," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1625- 1634, Dec 2005. Abstract Link Full Text Abstract: This paper presents the modeling, simulation, and control aspects of four-quadrant switched reluctance motor (SRM) drives. The design of SRM drive systems must be focused on application-based appropriate control and engineering solutions needed to overcome the practical issues. A complex model is described for the physical motor simulation to incorporate the important dynamics of the SRM. A simpler, but quite accurate, model is presented for the SRM controller. Various practical limitations have been incorporated in the simulation model to make it closer to the experimental setup. The SRM control parameters are chosen based on torque-per-ampere maximization requirement. Experimental results for a 1.0-kW SRM obtained on a digital platform are presented along with useful guidelines for prototype implementation.
52.6.18	B. Parreira, S. Rafael, A.J. Pires, P.J.C. Branco, "Obtaining the magnetic characteristics of an 8/6 switched reluctance machine: from FEM analysis to the experimental tests," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1635- 1643, Dec 2005. Abstract Link Full Text Abstract: This paper describes the procedure for modeling an 8/6 switched reluctance machine (SRM) step-by-step. First, the geometry and mechanical parameters of the machine are established, when a finite-element modeling (FEM) approach is initially developed to obtain the flux linkage/current/rotor position relationship so that the proper and mutual inductances and also its torque and field distribution characteristics can then be computed. Afterward, a series of experimental tests are performed to obtain the magnetic characteristics of the machine, comparing, correcting, and discussing the results with those of FEM analysis.
52.6.19	J. Pan, N.C. Cheung, Jinming Yang, "High-precision position control of a novel planar switched reluctance motor," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1644- 1652, Dec 2005. Abstract Link Full Text Abstract: This paper presents the position control of a novel two-dimensional (2-D) switched reluctance (SR) planar motor. The planar motor consists of a six-coil moving platform and a flat stator base made from laminated mild steel blocks. Unlike conventional x-y tables, which stack two moving slides on top of each other, the proposed 2-D planar motor has the advantages of simple mechanical construction, high reliability, and the ability to withstand harsh operating conditions. Together with the two linear encoders attached to the x-axis and y-axis, the motor can be controlled under closed-loop mode. To combat the problem of force nonlinearity, this paper proposes a cascade controller with force linearization technique to implement the drive controller. Due to the unique structure of the planar motor's magnetic circuit, there is very little coupling between the x-axis and y-axis, and no decoupling compensation is needed. Preliminary results show that the proposed SR planar motor has a positional accuracy of 5 /spl mu/m and a maximum acceleration/deceleration rate of 2 G.
52.6.20	G.K. Singh, D.K.P. Singh, K. Nam, S.K. Lim, "A simple indirect field-oriented control scheme for multiconverter-fed induction motor," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1653- 1659, Dec 2005. Abstract Link Full Text Abstract: In multiconverter topology, several voltage-source pulsewidth modulation (PWM) inverters using common sinusoidal modulating signals and phase-shifted triangular carrier are operated in tandem with their outputs coupled through current sharing inductors, with an objective of increasing the overall rating to megawatt range, reducing the harmonic current and torque ripples, increasing the reliability with phase-redundant operation under various fault conditions. The individual PWM voltage-source inverter (VSI) operates with the devices switching at their optimum switching frequency and behaves as a linear power amplifier (LPA). The overall multiconverter exhibits an improved quality of alternating currents (ac) due to the multiplied carrier effects in PWM. This paper, therefore, presents a simple indirect field-oriented control scheme for the multiconverter-fed induction machine. Necessary experimental and simulation results are presented to show the effectiveness of the proposed indirect field-oriented control scheme. In the study, on-line analysis has been performed using C/sup ++/, while MATLAB/Simulink has been used to perform the off-line analysis. The paper also discusses the design philosophy of the two well-known topologies of the converters used for high-voltage and high-current applications to facilitate the design and development of near-future megavolt ampere rating power converters/conditioners.
52.6.21	E.D. Mitronikas, A.N. Safacas, "An improved sensorless vector-control method for an induction motor drive," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1660- 1668, Dec 2005. Abstract Link Full Text Abstract: In the present paper, a new improved sensorless vector-control method for an induction motor drive is presented. The proposed method is based on an improved closed-loop stator-flux estimator, based on the dynamic model of the asynchronous motor, which achieves precise stator-flux estimation over a wide area of operation. This new stator-flux estimator ensures stability of the overall control scheme in a very-wide-speed operation area, as it will be shown in this paper. The rotor-speed-estimation method is based on an observer based on the model reference adaptive systems (MRAS) theory. The control scheme is based on a stator-flux-oriented direct vector-control method, where both flux and speed controllers are optimal tuned. In addition, implementation of the proposed method is based on a simplified algorithm capable of running in a low-cost microcontroller, which is discussed in detail. Also, the motor-drive system, including the stator-flux estimator, the speed estimator, and the control logic are simulated and some characteristic simulation results are presented. These results reveal that the proposed method is able to obtain precise flux and speed control over a wide operation area, including very low operating frequencies. Emerging Technology
52.6.22	S. Skoczowski, S. Domek, K. Pietrusewicz, B. Broel-Plater, "A method for improving the robustness of PID control," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1669- 1676, Dec 2005. Abstract Link Full Text Abstract: In this paper, an effective method is proposed for robust proportional-integral-derivative (PID) control that is easily implementable on commonly used equipment such as programmable logic controller (PLC) and programmable automation controller (PAC). The method is based on a two-loop model following control (MFC) system containing a nominal model of the controlled plant and two PID controllers. Basic features exhibited by the MFC structure are presented, and a technique to tune both component controllers is given. The proposed structures have been implemented in a programmable logic controller and tested on control plants with perturbed parameters. Also, the proposed control system has been checked for its performance in cases when the operation of PID controllers is based on fuzzy logic. Tuning rules for the fuzzy controllers in the presented MFC system have been proposed. Results of tests lend support to the view that the proposed control structures may find wide application to robust control of plants with time-varying parameters.
52.6.23	Chih-Min Lin, Chun-Fei Hsu, "Recurrent-neural-network-based adaptive-backstepping control for induction servomotors," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1677- 1684, Dec 2005. Abstract Link Full Text Abstract: This study is concerned with the position control of an induction servomotor using a recurrent-neural-network (RNN)-based adaptive-backstepping control (RNABC) system. The adaptive-backstepping approach offers a choice of design tools for the accommodation of system uncertainties and nonlinearities. The RNABC system is comprised of a backstepping controller and a robust controller. The backstepping controller containing an RNN uncertainty observer is the principal controller, and the robust controller is designed to dispel the effect of approximation error introduced by the uncertainty observer. Since the RNN has superior capabilities compared to the feedforward NN for dynamic system identification, it is utilized as the uncertainty observer. In addition, the Taylor linearization technique is employed to increase the learning ability of the RNN. Meanwhile, the adaptation laws of the adaptive-backstepping approach are derived in the sense of the Lyapunov function, thus, the stability of the system can be guaranteed. Finally, simulation and experimental results verify that the proposed RNABC can achieve favorable tracking performance for the induction-servomotor system, even with regard to parameter variations and input-command frequency variation.
52.6.24	Jung-Wook Park, G.K. Venayagamoorthy, R.G. Harley, "MLP/RBF neural-networks-based online global model identification of synchronous generator," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1685- 1695, Dec 2005. Abstract Link Full Text Abstract: This paper compares the performances of a multilayer perceptron neural network (MLPN) and a radial basis function neural network (RBFN) for online identification of the nonlinear dynamics of a synchronous generator in a power system. The computational requirement to process the data during the online training, local convergence, and online global convergence properties are investigated by time-domain simulations. The performances of the identifiers as a global model, which are trained at different stable operating conditions, are compared using the actual signals as well as the deviation signals for the inputs of the identifiers. Such an online-trained identifier with fixed optimal weights after the global convergence test is needed to provide information about the plant to a neurocontroller. The use of the fixed weights is to provide against a sensor failure in which case the training of the identifiers would be automatically stopped, and their weights frozen, but the control action, which uses the identifier, would be able to continue.
52.6.25	Jun Oh Febg, "Deadzone compensation of an XY-positioning table using fuzzy logic," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1696- 1701, Dec 2005. Abstract Link Full Text Abstract: A deadzone compensator is designed for an XY-positioning table using fuzzy logic. The classification property of fuzzy-logic systems makes them a natural candidate for the rejection of errors induced by the deadzone, which has regions in which it behaves differently. A tuning algorithm is given for the fuzzy-logic parameters, so that the deadzone-compensation scheme becomes adaptive, guaranteeing small tracking errors and bounded-parameter estimates. Formal nonlinear-stability proofs are given to show that the tracking error is small. The fuzzy-logic deadzone compensator is implemented on an XY-positioning table to show its efficacy. Letters to the Editor
52.6.26	Sang-Kyoo Han, Gun-Woo Moon, Myung-Joong Youn, "A novel current-fed energy-recovery sustaining driver for plasma display panel (PDP)," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1702- 1704, Dec 2005. Abstract Link Full Text Abstract: A novel current-fed energy-recovery sustaining driver (CFERSD) for a plasma display panel (PDP) is proposed. It uses the current source to recover the energy stored in a PDP, which also provides zero-voltage switching (ZVS) of all main switches and the improved operational voltage margin. Furthermore, it features a lower conduction loss and faster transition time. It is well suited for wall-hanging color televisions (TVs).
52.6.27	K.K. Chan, N.C. Cheung, "A novel two-finger variable-reluctance gripper for high-speed grasping of delicate objects: an implementation case study," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1705- 1707, Dec 2005. Abstract Link Full Text Abstract: The paper describes the development of a novel two-finger gripper using variable-reluctance (VR) technology. A model is constructed and verified by experimentation. Results show that the proposed gripper inherits many of the advantages of VR actuators, including ease of construction, low cost, high robustness, and high reliability.
52.6.28	F. Jurado, "Novel fuzzy flux control for fuel-cell inverters," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1707- 1710, Dec 2005. Abstract Link Full Text Abstract: Fuel cells probably represent the power-production technology receiving the most development attention. The objective of this paper is to regulate the output voltage of inverters for fuel-cell power plants. This letter describes an effective fuzzy-logic (FL) flux control. The paper demonstrates that the proposed method provides an improved response compared to the conventional flux-control method.
52.6.29	Sewan Choi, "A three-phase unity-power-factor diode rectifier with active input current shaping," IEEE Trans. on Industrial Electronics, vol. 52, no. 6, pp. 1711- 1714, Dec 2005. Abstract Link Full Text Abstract: This paper proposes a new three-phase diode rectifier that actively shapes the input current by means of two direct current dc-dc converters operating at continuous conduction mode. The proposed approach draws sinusoidal input current at unity power factor and has output voltage regulation capability. The size and weight of the magnetic devices is reduced since a low-kilovolt-ampere three-phase autotransformer is incorporated and dc outputs of two bridges are directly connected without using low-frequency interphase transformers (IPTs).