IEEE Transactions on Industrial Electronics 

Volume 49,  Number 1, Feb 2002           Access to the journal on IEEE XPLORE     IE Transactions Home Page



                 Special Section on SRM and Drives

49.1.1    M. Ehsani, "Guest Editorial," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 2-2, Feb 2002.   Abstract Link    Full Text

Abstract: Not Available

49.1.2    D.A. Torrey, "Switched reluctance generators and their control," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 3-14, Feb 2002.   Abstract Link    Full Text

Abstract: This paper discusses how the switched reluctance generator (SRG) converts energy as directed by a controller. Beginning with a review of the electromechanics of generation, the paper identifies the implications of the energy conversion process on how the SRG is controlled. The structure of the SRG controller for speed-control and power-control applications is discussed. Practical implementation details for commutation of the SRG are reviewed. Concepts are illustrated with a 6-kW SRG designed to serve as a starter/alternator in automotive applications

49.1.3    T.J.E. Miller, "Optimal design of switched reluctance motors," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 15-27, Feb 2002.   Abstract Link    Full Text

Abstract: The fundamental theory of the switched reluctance motor is presented with a number of new equations. It is used to show how the practical development of a design calculation should proceed, and this leads to a discussion of physical characteristics required to achieve satisfactory performance and to reduce acoustic noise. The paper makes a few generic observations on the characteristics of successful products that use switched reluctance motors. It is written at a basic engineering level and makes no attempt to apply sophisticated optimization theory

49.1.4    I. Husain, "Minimization of torque ripple in SRM drives," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 28-39, Feb 2002.   Abstract Link    Full Text

Abstract: The torque pulsations in switched reluctance motors (SRMs) are relatively higher compared to sinusoidal machines due to the doubly salient structure of the motor. The magnetization pattern of the individual phases together with the T-i-&thetas; characteristics of the motor dictate the amount of torque ripple during operation. Both machine design and electronic control approaches have been used to minimize the torque ripple in SRMs. This paper presents an extensive review of the origin of torque ripple and the approaches adopted over the past decade to minimize the torque ripple. A hybrid torque-ripple-minimizing controller that incorporates the attractive features of some of the techniques developed in the past decade is presented along with simulation and experimental results

49.1.5    M. Ehsani, B. Fahimi, "Elimination of position sensors in switched reluctance motor drives: state of the art and future trends," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 40-47, Feb 2002.   Abstract Link    Full Text

Abstract: This paper covers the range of topics related to sensorless control of switched reluctance motor (SRM) drives from their fundamentals to their limitations and state of the art and future trends. This should help the reader to develop a systematic understanding of the sensorless techniques that have been developed over the past two decades. The inherent vulnerability to mechanical failures, extra cost, and size associated with external position sensors such as optical encoders, resolvers, and custom-designed Hall-effect sensors has motivated many researchers to develop sensorless control techniques for SRM drives. Ideally, it is desirable to have a sensorless scheme, which uses only terminal measurements and does not require additional hardware or memory while maintaining a reliable operation over the entire speed and torque range with high resolution and accuracy. Advances in the development of low-cost digital-signal-processor-based microcontrollers have paved the way for the fulfillment of this objective. It is, furthermore, our view that the existing trends in the development of more powerful processors will ultimately replace the concept of sensorless controls with the concept of eliminating the need for position sensing, a concept that will further revolutionize the motor drive technology

49.1.6    R.B. Inderka, M. Menne, R.W.A.A. De Doncker, "Control of switched reluctance drives for electric vehicle applications," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 48-53, Feb 2002.   Abstract Link    Full Text

Abstract: Dynamic controllers of switched reluctance drives adjust at least three variables, i.e., current amplitude, turn-on, and turn-off angles. In electric vehicle (EV) applications high efficiency of the drive over a wide speed range, wide torque bandwidth, and low torque ripple under varying DC-bus voltage conditions are important design goals. Hence, controllers of switched reluctance drives for EVs usually have a complex structure. In this paper, the demands on control accuracy of switched reluctance machine traction drives and the traction controller sampling frequency, which are necessary to take advantage of the switched reluctance machine dynamic capabilities, are discussed. To integrate the traction drive, the control commands need to be actualized with a sampling frequency of at least 100 Hz to meet the high-dynamic requirements of modern vehicle control systems, e.g., active cruise control, antislip control, and active damping of mechanical drivetrain oscillations. It is found that the switching angles have to be adjusted within one-tenth of a mechanical degree. This study shows that switched reluctance drives can fulfill all requirements needed for electric propulsion using standard microcontrollers or digital signal processors

49.1.7    J. Reinert, S. Schroder, "Power-factor correction for switched reluctance drives," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 54-57, Feb 2002.   Abstract Link    Full Text

Abstract: This paper evaluates the need for power-factor correction (PFC) in switched reluctance drive systems supplied from single-phase mains. The aim is to achieve interference values lower than the prescribed norms at minimal system costs and volume. It is shown that for certain applications, a PFC circuit has to be implemented, but simpler technical solutions are often possible. Finally, a suggestion is presented as to how a low-cost power-factor-corrected system should be built for high-volume production


Drive Control
49.1.8    M. El-Habrouk, M.K. Darwish, "A new control technique for active power filters using a combined genetic algorithm/conventional analysis," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 58-66, Feb 2002.   Abstract Link    Full Text

Abstract: In this paper, the computational problems associated with the optimization techniques used to evaluate the switching patterns for controlling variable-characteristics active power filters are presented and critically analyzed. Genetic algorithms (GAs) are introduced in this paper to generate a fast and accurate initial starting point in the highly nonlinear optimization space of mathematical optimization techniques. GAs tend to speed up the initialization process by a factor of 13. A combined GA/conventional technique is also proposed and implemented to reduce the associated computational burden associated with the control and, consequently, increasing the speed of response of this class of active filters. Comparisons of these techniques are discussed and presented in conjunction with simulation and practical results for the filter operation

49.1.9    Tsang-Li Tai, Jian-Shiang Chen, "UPS inverter design using discrete-time sliding-mode control scheme ," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 67-75, Feb 2002.   Abstract Link    Full Text

Abstract: This paper presents a novel discrete-time sliding-mode control algorithm for an uninterruptible power supply (UPS) inverter design. The approach offers a dual-loop design, in which a current predictor utilizes the tracking error of output voltage to estimate the desired inductor current, while a current controller is adopted to regulate the inductor current and, thus, produces a control command to the pulsewidth modulation inverter. An explicit condition for stable controller design is derived. The efficacy of this scheme is validated via a successful implementation on a digital-signal-processor-based UPS inverter. The proposed scheme has shown its robustness on low output voltage distortion, excellent voltage regulation, and it is insensitive to load variation, even under nonlinear loads. Experimental studies were performed to further validate the effectiveness of this scheme

49.1.10    T. Suntio, I. Gadoura, K. Zenger, "Input filter interactions in peak-current-mode-controlled buck converter operating in CICM," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 76-86, Feb 2002.   Abstract Link    Full Text

Abstract: Peak-current-mode (PCM) control is a widely used method to control switched-mode converters. Most often an input filter is necessary to meet electromagnetic interference requirements. The input filter can cause instability and degradation of input and output dynamics if not properly designed. The input filter design from the output dynamics viewpoint has been addressed in numerous papers, resulting in well-agreed results in the case of direct duty-ratio control. The same methods and criteria have also been applied to PCM control, but the results have turned out to be conflicting. This paper shows that the adverse effect of the input filter on the output performance of a peak-current-controlled buck converter in continuous inductor-current mode is insignificant. The input performance is, however, significantly affected, necessitating the use of proper damping. It is also shown that the instability is caused solely by the instability of the input filter under negative incremental resistance. The methods used are unified in nature, but the results obtained in this study cannot be generalized to be valid for types of converters other than a buck converter

49.1.11    M. Rodic, K. Jezernik, "Speed-sensorless sliding-mode torque control of an induction motor ," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 87-95, Feb 2002.   Abstract Link    Full Text

Abstract: Novel induction motor control optimizing both torque response and efficiency is proposed in the paper. The main contribution of the paper is a new structure of rotor flux observer aimed at the speed-sensorless operation of an induction machine servo drive at both low and high speed, where rapid speed changes can occur. The control differs from the conventional field-oriented control. Stator and rotor flux in stator fixed coordinates are controlled instead of the stator current components in rotor field coordinates isd and isq. In principle, the proposed method is based on driving the stator flux toward the reference stator flux vector defined by the input command, which are the reference torque and the reference rotor flux. The magnitude and orientation angle of the rotor flux of the induction motor are determined by the output of the closed-loop rotor flux observer based on sliding-mode control and Lyapunov theory. Simulations and experimental tests are provided to evaluate the consistency and performance of the proposed control technique

49.1.12    Hong-Zhou Tan, N. Sepehri, "Parametric fault diagnosis for electrohydraulic cylinder drive units," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 96-106, Feb 2002.   Abstract Link    Full Text

Abstract: A novel model-based methodology for fault diagnosis (FD) of nonlinear hydraulic drive systems is presented in this paper. Due to its linear dependence upon parameters, a second-truncated Volterra nonlinear model is first used to characterize such systems. The versatile order-recursive estimation scheme is employed to determine the values of parameters in the Volterra model. The scheme also avoids separate determination of the model order; thus, the complexity of the search process is reduced. Next, it is shown that the estimated parameters, representing different states of the system, normal as well as faulty conditions, can be used to detect and isolate system faults in a geometric domain. Very promising results are exhibited via simulations as well as laboratory experiments. It is concluded that the developed parametric FD technique has potential to provide efficient condition monitoring and/or preventive maintenance in hydraulic actuator circuits

49.1.13    F. Grasser, A. D'Arrigo, S. Colombi, A.C. Rufer, "JOE: a mobile, inverted pendulum," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 107-114, Feb 2002.   Abstract Link    Full Text

Abstract: The Industrial Electronics Laboratory at the Swiss Federal Institute of Technology, Lausanne, Switzerland, has built a prototype of a revolutionary two-wheeled vehicle. Due to its configuration with two coaxial wheels, each of which is coupled to a DC motor, the vehicle is able to do stationary U-turns. A control system, made up of two decoupled state-space controllers, pilots the motors so as to keep the system in equilibrium

49.1.14    Chih-Min Lin, Chun-Fei Hsu, "Neural-network-based adaptive control for induction servomotor drive system," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 115-123, Feb 2002.   Abstract Link    Full Text

Abstract: A neural-network-based adaptive control (NNAC) design method is proposed to control an induction servomotor. In this NNAC design, a neural network (NN) controller is investigated to mimic a feedback linearization control law; and a compensation controller is designed to compensate for the approximation error between the feedback linearization control law and the NN controller. The interconnection weights of the NN can be online tuned in the sense of the Lyapunov stability theorem; thus, the stability of the control system can be guaranteed. Additionally, in this NNAC system design, an error estimation mechanism is investigated to estimate the bound of approximation error so that the chattering phenomenon of the control effort can be reduced. Simulation and experimental results show that the proposed NNAC servomotor control systems can achieve favorable tracking and robust performance with regard to parameter variations and external load disturbances

49.1.15    K.L. Shi, T.F. Chan, Y.K. Wong, S.L. Ho, "Speed estimation of an induction motor drive using an optimized extended Kalman filter," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 124-133, Feb 2002.   Abstract Link    Full Text

Abstract: This paper presents a novel method to achieve good performance of an extended Kalman filter (EKF) for speed estimation of an induction motor drive. A real-coded genetic algorithm (GA) is used to optimize the noise covariance and weight matrices of the EKF, thereby ensuring filter stability and accuracy in speed estimation. Simulation studies on a constant V/Hz controller and a field-oriented controller (FOC) under various operating conditions demonstrate the efficacy of the proposed method. The experimental system consists of a prototype digital-signal-processor-based FOC induction motor drive with hardware facilities for acquiring the speed, voltage, and current signals to a PC. Experiments comprising offline GA training and verification phases are presented to validate the performance of the optimized EKF

49.1.16    Faa-Jeng Lin, Rong-Jong Wai, Wen-Der Chou, Shu-Peng Hsu, "Adaptive backstepping control using recurrent neural network for linear induction motor drive," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 134-146, Feb 2002.   Abstract Link    Full Text

Abstract: An adaptive backstepping control system using a recurrent neural network (RNN) is proposed to control the mover position of a linear induction motor (LIM) drive to compensate the uncertainties including the friction force in this paper. First, the dynamic model of an indirect field-oriented LIM drive is derived. Then, a backstepping approach is proposed to compensate the uncertainties including the friction force occurred in the motion control system. With the proposed backstepping control system, the mover position of the LIM drive possesses the advantages of good transient control performance and robustness to uncertainties for the tracking of periodic reference trajectories. Moreover, to further increase the robustness of the LIM drive, an RNN uncertainty observer is proposed to estimate the required lumped uncertainty in the backstepping control system. In addition, an online parameter training methodology, which is derived using the gradient-descent method, is proposed to increase the learning capability of the RNN. The effectiveness of the proposed control scheme is verified by both the simulated and experimental results

49.1.17    R. Leidhold, G. Garcia, M.I. Valla, "Field-oriented controlled induction generator with loss minimization," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 147-156, Feb 2002.   Abstract Link    Full Text

Abstract: In this paper, a strategy to control an induction generator (IG) working with variable speed and load is presented and discussed. An inverter and a field-oriented controller are used in order to excite the induction machine (IM) efficiently, minimizing copper and iron losses, and to regulate the generated voltage. The proposed IG system is a stand-alone (not grid connected) system. It is used to produce electrical DC energy, to charge a battery bank, and/or to supply DC loads with maximum efficiency. A laboratory setup, based on a conventional 4 kW squirrel-cage IM, has been implemented. Experimental results are presented in order to validate the proposed strategy


Power Electronics
49.1.18    H.A. Toliyat, L. Hao, D.S. Shet, T.A. Nondahl, "Position-sensorless control of surface-mount permanent-magnet AC (PMAC) motors at low speeds," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 157-164, Feb 2002.   Abstract Link    Full Text

Abstract: A position-sensorless field-oriented control scheme for a surface-mount permanent-magnet AC (PMAC) motor is presented. A digital signal processor is used to implement the sensorless scheme. The PMAC stator is wound like that of a conventional three-phase induction motor. The coils of the motor are all brought out and it is possible to connect the motor in different configurations. Taps are also provided which are used for voltage measurements. By measuring the tap voltages, absolute position of the PMAC motor is estimated. The estimated position information is independent of the stator resistance, thus, this scheme is even applicable at low speeds. Results are presented to show the effectiveness of the new sensorless scheme

49.1.19    Hang-Seok Choi, Bo Hyung Cho, "Novel zero-current-switching (ZCS) PWM switch cell minimizing additional conduction loss," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 165-172, Feb 2002.   Abstract Link    Full Text

Abstract: This paper proposes a new zero-current-switching (ZCS) pulsewidth modulation (PWM) switch cell that has no additional conduction loss of the main switch. In this cell, the main switch and the auxiliary switch turn on and turn off under zero-current condition. The diodes commutate softly and the reverse-recovery problems are alleviated. The conduction loss and the current stress of the main switch are minimized, since the resonating current for the soft switching does not flow through the main switch. Based on the proposed ZCS PWM switch cell, a new family of DC-to-DC PWM converters is derived. The new family of ZCS PWM converters is suitable for the high-power applications employing insulated gate bipolar transistors. Among the new family of DC-to-DC PWM converters, a boost converter was taken as an example and has been analyzed. Design guidelines with a design example are described and verified by experimental results from the 2.5 kW prototype boost converter operating at 40 kHz

49.1.20    Bor-Ren Lin, Yi-Lang Hou, "Single-phase integrated power quality compensator based on capacitor-clamped configuration," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 173-185, Feb 2002.   Abstract Link    Full Text

Abstract: A control scheme of an integrated power quality compensator, which employs an active rectifier to work simultaneously as an active power filter (APF) to decrease current harmonics, is proposed. The employed rectifier is based on a capacitor-clamped configuration to produce multilevel pulsewidth modulation waveforms which result in low voltage stress and low conduction loss on the power switches. The proposed active rectifier is controlled to track the supply current to be a sinusoidal wave with low current harmonics. The advantages of the proposed control scheme are high power factor, low current harmonics, no complicated calculations for current harmonics elimination, and no dedicated APF needed for harmonic elimination. The experimental results are used to verify the validity and effectiveness of the proposed control scheme

49.1.21    Keliang Zhou, Danwei Wang, "Relationship between space-vector modulation and three-phase carrier-based PWM: a comprehensive analysis [three-phase inverters]," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 186-196, Feb 2002.   Abstract Link    Full Text

Abstract: This paper comprehensively analyzes the relationship between space-vector modulation and three-phase carrier-based pulse width modulation (PWM). The relationships involved, such as the relationship between modulation signals (including zero-sequence component and fundamental components) and space vectors, the relationship between the modulation signals and the space-vector sectors, the relationship between the switching pattern of space-vector modulation and the type of carrier, and the relationship between the distribution of zero vectors and different zero-sequence signal are systematically established. All the relationships provide a bidirectional bridge for the transformation between carrier-based PWM modulators and space-vector modulation modulators. It is shown that all the drawn conclusions are independent of the load type. Furthermore, the implementations of both space-vector modulation and carrier-based PWM in a closed-loop feedback converter are discussed

49.1.22    C. Chakraborty, M. Ishida, Y. Hori, "Novel half-bridge resonant converter topology realized by adjusting transformer parameters," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 197-205, Feb 2002.   Abstract Link    Full Text

Abstract: This paper shows a new direction as to how the transformer parameters may be best utilized and presents the performance and control of novel DC/DC and AC/DC converter topologies. All three inductances of a transformer have been utilized to realize a CL3 topology having excellent characteristics and requiring no external inductor. For the half-bridge topology, the capacitor used for the purpose of input voltage splitting also serves as the resonating capacitor. Thus, in the half-bridge version, the topology is realized only with a specially designed transformer and no other external components. A laboratory setup is produced and experiments conducted for DC/DC and AC/DC applications. A new design procedure and control technique for the converters are also presented. These topologies are very promising in small-power applications

49.1.23    Feel-Soon Kang, Sung-Jun Park, Cheul-U Kim, "ZVZCS single-stage PFC AC-to-DC half-bridge converter," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 206-216, Feb 2002.   Abstract Link    Full Text

Abstract: A zero-voltage- and zero-current-switched single-stage AC-to-DC half-bridge converter with high power factor is presented to reduce the switching losses and to achieve sinusoidal, unity power factor input currents. The single-stage approach, which combines a boost converter used as power-factor correction with a half-bridge converter used as DC-to-DC conversion into one power stage, has a simple structure and low cost. At the same time, the switching losses could be considerably reduced, because the switches of the proposed converter are designed to be turned on at zero voltage and off at zero current. Detailed analysis and experimental results are presented on the proposed converter, which is operated at constant switching frequency and in discontinuous conduction mode

49.1.24    T. Noguchi, S. Togashi, R. Nakamoto, "Short-current pulse-based maximum-power-point tracking method for multiple photovoltaic-and-converter module system," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 217-223, Feb 2002.   Abstract Link    Full Text

Abstract: This paper proposes a novel maximum-power-point tracking (MPPT) method with a simple algorithm for photovoltaic (PV) power generation systems. The method is based on use of a short-current pulse of the PV to determine an optimum operating current where the maximum output power can be obtained and completely differs from conventional hill-climbing-based methods. In the proposed system, the optimum operating current is instantaneously determined simply by taking a product of the short-current pulse amplitude and a parameter k because the optimum operating current is exactly proportional to the short current under various conditions of illuminance and temperature. Also, the system offers an identification capability of k by means of fast power-versus-current curve scanning, which makes the short-current pulse-based MPPT method adaptive to disturbances such as shades partially covering the PV panels and surface contamination. The above adaptive MPPT algorithm has been introduced into a current-controlled boost chopper and a multiple power converter system composed of PV-and-chopper modules. Various operating characteristics have experimentally been examined on this multiple PV-and-chopper module system from a practical viewpoint and excellent MPPT performance has been confirmed through the tests


Robotics and Vision
49.1.25    A. Visioli, G. Legnani, "On the trajectory tracking control of industrial SCARA robot manipulators," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 224-232, Feb 2002.   Abstract Link    Full Text

Abstract: In this paper, the authors discuss, from an experimental point of view, the use of different control strategies for the trajectory tracking control of an industrial selective compliance assembly robot arm robot, which is one of the most employed manipulators in industrial environments, especially for assembly tasks. Specifically, they consider decentralized controllers such as proportional-integral-derivative-based and sliding-mode ones and model-based controllers such as the classical computed-torque one and a neural-network-based controller. A simple procedure for the estimation of the dynamic model of the manipulator is given. Experimental results provide a detailed framework about the cost/benefit ratio regarding the use of the different controllers, showing that the performance obtained with decentralized controllers may suffice in a large number of industrial applications, but in order to achieve low tracking errors also for high-speed trajectories, it might be convenient to adopt a neural-network-based control scheme, whose implementation is not particularly demanding

49.1.26    B. Nemec, L. Zlajpah, "Force control of redundant robots in unstructured environment," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 233-240, Feb 2002.   Abstract Link    Full Text

Abstract: In this paper, a method for force control of redundant robots in an unstructured environment is proposed. We assume that the obstacles are not known in advance. Hence, the robot arm has to be compliant with the environment while tracking the desired position and force at the end-effector. First, the dynamic properties of the internal motion of redundant manipulators are considered. The motion is decoupled into the end-effector motion and the internal motion. Next, the dynamic model of a redundant manipulator is derived. Special attention is given to the inertial properties of the system in the space where internal motion is taking place; the authors define a null-space effective inertia and its inverse. Finally, a control method is proposed which completely decouples the motion of the manipulator into the task-space motion and the internal motion and enables the selection of dynamic characteristics in both subspaces separately. The proposed method is verified with simulation and with experimental results of a four-degrees-of-freedom planar redundant robot

49.1.27    Y. Umeda, T. Yakoh, "Configuration and readhesion control for a mobile robot with external sensors," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 241-247, Feb 2002.   Abstract Link    Full Text

Abstract: Since a wheeled mobile robot is subject to nonholonomic constraints, the position and the configuration of the robot cannot be derived directly from only the rotation angle of its wheels. In other words, the position and the configuration of a mobile robot cannot be calculated correctly if its wheels skid. For the purpose of the position estimation of a mobile robot, some external sensors are used, in general. This paper uses position information from a position-sensitive detector camera that is a high-speed visual sensor to correct the errors that are due to skid and so on. Also, we estimate a skid of wheels by using its visual information. In this paper, the authors propose a control system that enables control of both the configuration of the robot and the skid of wheels simultaneously by including these estimated values in the control loop of a mobile manipulator

49.1.28    T. Murakami, K. Kahlen, R.W.A.A. De Doncker, "Robust motion control based on projection plane in redundant manipulator," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 248-255, Feb 2002.   Abstract Link    Full Text

Abstract: This paper describes a novel approach of robust motion control of a redundant manipulator by projection planes. In the proposed approach, a robust controller based on a workspace observer is employed in the selectable projection plane. Then, an adequate selection of the projection planes makes it possible to simplify the controller without deteriorating the tip motion response and to obtain the desired motion in the null space of the manipulator. This is one of the remarkable features of the proposed approach. The validity of the proposed controller is confirmed by several numerical simulations


Emerging Technology
49.1.29    Shyh-Jier Huang, Fu-Sheng Pai, "Design and operation of burn-in test system for three-phase uninterruptible power supplies," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 256-263, Feb 2002.   Abstract Link    Full Text

Abstract: In this paper, a new approach for the burn-in test of three-phase uninterruptible power supplies is proposed. This method can perform the energy recovery for reducing the test cost, while the current supplied from the utility can be steered to be more sinusoidal. When a large number of burn-in test systems are activated such that harmonic problems may become more serious, the proposed method is also suggested based on its immunity to possible harmonies infiltration coming from the tested product to the utility power supplies. This method has been tested through simulation study and hardware experiments. Test results help consolidate the feasibility of the approach for the applications considered


Letters to the Editor

49.1.30    R.R. Mudholkar, S.R. Sawant, "Fuzzy logic transformer build estimation," IEEE Trans. on Industrial Electronics, vol. 49, no. 1, pp. 264-267, Feb 2002.   Abstract Link    Full Text

Abstract: Mechanical fitting of transformer windings tightly into the core ensures an efficient use of window space. Fuzzy logic transformer build estimation is intended to implement approximate solutions suggested in imprecise terms for the better mechanical fit of windings into the core. For imperfect fit, it readjusts the buildup parameters in iterations to optimize mechanical fit. The results have demonstrated the potentiality of usage of fuzzy logic in the mechanical-fit process of a transformer