Special Section Papers on Human-Adaptive
Mechatronics
1. S. Katsura, Y. Matsumoto, K. Ohnishi, "Realization of "Law of action and reaction" by multilateral control," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1196- 1205, Oct. 2005. Full Text Link Abstract : In recent years, the realization of a haptic system has been strongly desired in the fields of medical treatment and expert's skill acquisition. The key point of haptics is to realize a vivid presentation of reactive force, particularly in applications that involve touching action. In this paper, a realization of the "law of action and reaction" by multilateral control is introduced. First, an analysis and a design of bilateral control based on the disturbance observer are discussed. A disturbance observer is a basic technology for quarrying of disturbance torque and attainment of robust acceleration control. This paper shows that a four-channel controller which is composed of position control and force control in the acceleration dimension is decomposed into two modes: common and differential modes. A design of bilateral control is treated as position and force control in a single joint. The proposed method generates a good realization of reactive force for the slave side at the master side in bilateral force control. Second, bilateral control is extended and multilateral control is generalized. Multilateral control is designed similarly as bilateral control based on the modal decomposition. Robots with a haptic ability will have an important role in human adaptive mechatronics.
2. J. Kofman, Xianghai Wu, T.J. Luu, S. Verma, "Teleoperation of a robot manipulator using a vision-based human-robot interface," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1206- 1219, Oct. 2005. Full Text Link Abstract : Remote teleoperation of a robot manipulator by a human operator is often necessary in unstructured dynamic environments when human presence at the robot site is undesirable. Mechanical and other contacting interfaces used in teleoperation require unnatural human motions for object manipulation tasks or they may hinder human motion. Previous vision-based approaches have used only a few degrees of freedom for hand motion and have required hand motions that are unnatural for object manipulation tasks. This paper presents a noncontacting vision-based method of robot teleoperation that allows a human operator to communicate simultaneous six-degree-of-freedom motion tasks to a robot manipulator by having the operator perform the three-dimensional human hand-arm motion that would naturally be used to complete an object manipulation task. A vision-based human-robot interface is used for communication of human motion to the robot and for feedback of the robot motion and environment to the human operator. Teleoperation under operator position control was performed with high accuracy in object placement on a target. Semi-autonomous traded and shared control using robot-vision guidance aided in achieving a more accurate positioning and orientation of the end-effector for object gripping tasks.
3. Jin-Shyan Lee, Meng-Chu Zhou, Pau-Lo Hsu, "An application of Petri nets to supervisory control for human-computer interactive systems," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1220- 1226, Oct. 2005. Full Text Link Abstract : In a distributed robotic system, both human-controlled (semi-autonomous) and computer-controlled (fully autonomous) robots may simultaneously exist. From the global system's point of view, supervisory control for the interactions between the human and computer are important and necessary. For such human-computer interactive systems, this paper proposes a supervisory framework to guarantee that both human and computer commands meet collision-free and deadlock-free requirements. In the presented approach, Petri nets are applied to construct a system model and synthesize a desired supervisor. An application to a two-robot remote surveillance system is provided to demonstrate the practicability of the developed supervisory control approach. It is believed that the technique developed in this paper is significant in the industrial practice.
4. F. Miyawaki, K. Masamune, S. Suzuki, K. Yoshimitsu, J. Vain, "Scrub nurse robot system-intraoperative motion analysis of a scrub nurse and timed-automata-based model for surgery," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1227- 1235, Oct. 2005. Full Text Link Abstract : The goal of the project described in this paper is to develop a human-adaptive Scrub Nurse Robot (SNR) that can adapt to surgeons with various levels of skill and experience in order to compensate for the present severe shortage of scrub nurses. To determine the specifications of the SNR, we analyzed real intraoperative behavior of a scrub nurse, and then modeled the entire surgical procedure with key participants by a multilevel modeling approach using the extended timed-automata-based formalism of Uppaal. Specifically, first, we videotaped the intraoperative motions of a scrub nurse and a surgeon in a thoracoscopic surgery performed on an infant pig, and analyzed their motions during the skin incision. Second, the motions of the nurse's right wrist, elbow, and shoulder were modeled with the timed automata. Third, the entire surgical procedure as well as actions and statuses of key participants was also modeled. Finally, it is shown that the proposed multilevel modeling approach also facilitates the model checking that is considered efficient in the SNR motion analysis and its adaptive motion planning.
5. K. Furuta, M. Iwase, S. Hatakeyama, "Internal model and saturating actuation in human operation from view of human-adaptive mechatronics," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1236- 1245, Oct. 2005. Full Text Link Abstract : Human-adaptive mechatronics (HAM) is the area of mechatronics which adapts to the operator skill and assists its improvement. The analysis of human control action is one of the fundamental problems in the study of HAM. A special feature of human control action is the action being saturated with respect to the amplitude and velocity. At the same time, the human does not pay attention continuously to the response but intermittently scans and gets the information. In this paper, the continuous control action based on the scanned information is studied, and the desired trajectory of the human control action is considered to be generated by the closed-loop system including the internal model in the feedback path. Since the visual information is scanned intermittently, the closed-loop reference generator is considered as a sampled-hold system. The feedforward function of the cerebellum can be interpreted as the reference generator with a long scanning interval for the skilled operation. The saturating control action causing the pilot-induced oscillation is studied by taking the swing-up control of a single pendulum from the pendant to the upright position as an example. The two swing-up control laws are studied for reachability of the unstable nonlinear pendulum. One is the linear combination of sine function of the position and angular velocity, and the other is the variable-structure control for the sliding-mode function similar to the linear combination control law. The reachability is analyzed successfully by the color map.
Power Electronics
6. Leung-Pong Wong, D.K.-W. Cheng, M.H.L. Chow, Yim-Shu Lee, "Interleaved three-phase forward converter using integrated transformer," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1246- 1260, Oct. 2005. Full Text Link Abstract : An interleaved three-phase forward converter using an integrated transformer is proposed in this paper. This type of converter has the attractive features of flexible voltage conversion ratio, high output current (due to the parallel connection of outputs), near-zero output-current ripple (due to the output-current-ripple cancellation), fast transient response (due to the small effective output-filtering inductance), and is particularly suitable for high-output-current and low-output-voltage applications such as telecommunication and computer systems. The integrated transformer of the proposed converter consists of three step-down transformers on a single magnetic core. The z-parameter (gyrator) model and the equivalent-circuit model of the integrated transformer are derived. Based on the equivalent-circuit model, the principle of operation of the proposed converter is explained. The analysis and design criteria of the basic circuit, the operation of the regenerative LC snubber circuit, the simulation, and experimental verification are also described.
7. J.L. Russi, M.Ld.S. Martins, H.A. Grundling, H. Pinheiro, J.R. Pinheiro, H.L. Hey, "A unified design criterion for ZVT DC-DC PWM converters with constant auxiliary Voltage source," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1261- 1270, Oct. 2005. Full Text Link Abstract : This paper proposes a design criterion for calculating the resonant auxiliary elements of zero-voltage transition dc-dc pulsewidth-modulated (PWM) converters that use a dc auxiliary voltage source. The proposed criterion is based on stored energy in resonant auxiliary elements and takes into account the influence of the auxiliary voltage source value. Using this criterion, the reactive energy can be kept at a minimum level and a reduction of the auxiliary elements current ratings is achieved, which leads to lower conduction losses and improved converter efficiency. In addition, a reduction in size of auxiliary magnetic elements can be accomplished. To illustrate the usefulness of the proposed design criterion, the paper compares results obtained from the True-PWM Zero-Voltage Switching pole boost converter designed according to the proposed criterion, and from the original design guidelines. Experimental results show an efficiency gain of about 1% for a wide load range and 1.5% at full load. In addition, a reduction of about 52% in the auxiliary transformer volume for the implemented prototype was achieved, ensuring a reduction in overall converter size. Experimental results were obtained using a 1-kW 100-kHz laboratory prototype.
8. Bosheng Sun, Zhiqiang Gao, "A DSP-based active disturbance rejection control design for a 1-kW H-bridge DC-DC power converter," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1271- 1277, Oct. 2005. Full Text Link Abstract : This paper presents the design and implementation of an advanced digital controller for a 1-kW H-bridge dc-dc power converter. A new control algorithm based on the active disturbance rejection concept is developed to cope with the highly nonlinear dynamics of the converter and the disturbances. An experimental digital control system is used to implement the new control strategy. It consists of a digital control board based on the TMS320C6711 digital signal processor chip, an analogy I/O board, and a complex programmable logic device pulsewidth-modulation generation board. Using a newly developed bandwidth-parametrization technique, an autotuning method based on noise quantification is also developed and tested. Experimental results show the advantages and flexibilities of the new control method for the H-bridge dc-dc power converter.
9. R.M.F. Neto, F.L. Tofoli, L.C. de Freitas, "A high-power-factor half-bridge doubler boost converter without commutation losses," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1278- 1285, Oct. 2005. Full Text Link Abstract : This paper proposes a high-power-factor half-bridge doubler boost converter without commutation losses, which provides high output voltages, i.e., from 600 to 900 V. The voltages across the semiconductor devices are low and approximately equal to the output voltage, as doubled output voltages and reduced high-frequency ripple can be achieved. A detailed mathematical analysis concerning its operation is presented, and simulation and experimental results describe the converter performance.
10. Jie Chang, "High-frequency and precision three-phase sine/PWM controller with near-zero frequency of MPU intervention-novel design supporting distributed AC drive systems," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1286- 1296, Oct. 2005. Full Text Link Abstract : Conventional pulsewidth-modulation (PWM) schemes fully depend on a microprocessor (MPU) for extensive real-time computation, intervention, and housekeeping, and are limited to applications at low fundamental frequencies and low precision. At 20-kHz switching, the overhead of a modern 16-bit CPU increases up to 90%, making virtually no time available for regular control tasks. It also has poor cycle-to-cycle accuracy of /spl plusmn/5-10 /spl mu/s. A novel self-managed high-frequency and precision PWM architecture and integrated circuit are developed for distributed drive control systems. This architecture permits near-zero interfacing rate with the coprocessor, thus eliminating the overhead of the MPU's intervention and housekeeping, while being capable of both asynchronous and synchronous PWM at a range of 0-1000 Hz of fundamental frequencies, expandable to several kilohertz. A cycle-to-cycle accuracy of 50 ns is achievable in precision open-loop control. Experimental results verify our new design. This effectively supports distributed ac drive systems with highly coordinated controls.
11. Yuang-Shung Lee, Ming-Wang Cheng, "Intelligent control battery equalization for series connected lithium-ion battery strings," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1297- 1307, Oct. 2005. Full Text Link Abstract : An intelligent battery equalization scheme based on fuzzy logic control is presented to adaptively control the equalizing process of series-connected lithium-ion batteries. The proposed battery equalization scheme is a bidirectional dc-dc converter with energy transferring capacitor that can be used to design the bidirectional nondissipative equalizer for a battery balancing system. Furthermore, it can be designed as a ripple-free converter for improving the input current distortion of the battery charge supply power system. A fuzzy-logic-controlled strategy is constructed with a set of membership functions to prescribe the cells equalizing behavior within a safe equalizing region for rapid cell voltage balancing. The simulation and experimental results show the advantage of the predicted equalizing performance of the lithium-ion battery stacks. The proposed fuzzy logic control battery equalization controller can abridge the equalization time about 32%. The proposed method maintains safe operation during the charge/discharge state in each lithium-ion cell of the battery strings.
12. Chwei-Sen Wang, O.H. Stielau, G.A. Covic, "Design considerations for a contactless electric vehicle battery charger," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1308- 1314, Oct. 2005. Full Text Link Abstract : This paper overviews theoretical and practical design issues related to inductive power transfer systems and verifies the developed theory using a practical electric vehicle battery charger. The design focuses on the necessary approaches to ensure power transfer over the complete operating range of the system. As such, a new approach to the design of the primary resonant circuit is proposed, whereby deviations from design expectations due to phase or frequency shift are minimized. Of particular interest are systems that are neither loosely nor tightly coupled. The developed solution depends on the selected primary and secondary resonant topologies, the magnetic coupling coefficient, and the secondary quality factor.
13. K. Kutluay, Y. Cadirci, Y.S. Ozkazanc, I. Cadirci, "A new online state-of-charge estimation and monitoring system for sealed lead-acid batteries in Telecommunication power supplies," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1315- 1327, Oct. 2005. Full Text Link Abstract : This paper presents a new, online, battery state-of-charge estimation and monitoring system for both the discharge and charge periods of sealed lead-acid batteries, commonly used in telecommunication power systems as backup power supplies. The proposed monitoring system is based on discharge time versus discharge rate data given in manufacturers' data sheets, and coulometric measurements, without the need for any battery voltage measurement under open-circuit conditions. The corresponding battery management system can perform both the online monitoring and battery charging tasks by the use of the same low-cost 8-bit microcontroller. Battery state-of-charge monitoring tests have been carried out under both constant and dynamic load conditions and for alternate charge-discharge cycles of lead-acid batteries of different capacities, and for different operating temperatures. The test results have shown that a very good accuracy (better than 3%-4%) in the estimation of available capacity is obtained for various charge-discharge strategies corresponding to practical operating conditions. Changes in battery characteristics which occur due to aging are also taken into account by estimating the actual capacity of the battery and adopting the corresponding recharacterization of the aged cells automatically.
14. Yi-Hwa Liu, Jen-Hao Teng, Yu-Chung Lin, "Search for an optimal rapid charging pattern for lithium-ion batteries using ant colony system algorithm," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1328- 1336, Oct. 2005. Full Text Link Abstract : Commercial lithium-ion batteries are playing important roles as supplies for mobile phones, laptop computers, and other electronics. In order to maximize the performance of lithium-ion batteries, an advanced rapid charging pattern is required. In this paper, an Ant-Colony-System (ACS)-based algorithm is presented. The proposed ACS-based algorithm can be integrated into a commercially available battery tester to search for the optimal rapid charging pattern. Experimental results show that the obtained rapid charging pattern is capable of charging the lithium-ion batteries to 70% capacity in 30 min. The obtained pattern also provides 25% more cycle life than the conventional constant current-constant voltage method.
15. M. Bhatt, W.G. Hurley, W.H. Wolfle, "A new approach to intermittent charging of valve-regulated lead-acid batteries in standby applications," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1337- 1342, Oct. 2005. Full Text Link Abstract : For many years, intensive research has been undertaken to increase the life of valve-regulated lead-acid (VRLA) batteries. Overcharging results in excessive temperature in the battery, which degrades the chemical composition of the electrolyte. When the battery reaches the end-of-charge state, the energy being supplied to the battery is no longer consumed in the charge reaction and this additional energy is dissipated as heat within the battery. At this point, the oxygen cycle accelerates, which leads to temperature rise inside the battery. State-of-the-art control technology is required to control the charging of the battery and prevent the battery going into thermal runaway. This paper discusses the charging strategies for VRLA batteries in standby applications. Intermittent charging decreases the continuous overcharge which arises in the case of float charging. The charging regime used in intermittent charging must ensure the full recharge of the battery. This paper describes a new efficient method of charging batteries employing an intermittent charging technique called "Interrupted Charge Control." Laboratory tests and results are presented.
16. A. Affanni, A. Bellini, G. Franceschini, P. Guglielmi, C. Tassoni, "Battery choice and management for new-generation electric vehicles," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1343- 1349, Oct. 2005. Full Text Link Abstract : Different types of electric vehicles (EVs) have been recently designed with the aim of solving pollution problems caused by the emission of gasoline-powered engines. Environmental problems promote the adoption of new-generation electric vehicles for urban transportation. As it is well known, one of the weakest points of electric vehicles is the battery system. Vehicle autonomy and, therefore, accurate detection of battery state of charge (SoC) together with battery expected life, i.e., battery state of health, are among the major drawbacks that prevent the introduction of electric vehicles in the consumer market. The electric scooter may provide the most feasible opportunity among EVs. They may be a replacement product for the primary-use vehicle, especially in Europe and Asia, provided that drive performance, safety, and cost issues are similar to actual engine scooters. The battery system choice is a crucial item, and thanks to an increasing emphasis on vehicle range and performance, the Li-ion battery could become a viable candidate. This paper deals with the design of a battery pack based on Li-ion technology for a prototype electric scooter with high performance and autonomy. The adopted battery system is composed of a suitable number of cells series connected, featuring a high voltage level. Therefore, cell equalization and monitoring need to be provided. Due to manufacturing asymmetries, charge and discharge cycles lead to cell unbalancing, reducing battery capacity and, depending on cell type, causing safety troubles or strongly limiting the storage capacity of the full pack. No solution is available on the market at a cheap price, because of the required voltage level and performance, therefore, a dedicated battery management system was designed, that also includes a battery SoC monitoring. The proposed solution features a high capability of energy storing in braking conditions, charge equalization, overvoltage and undervoltage protection and, obviously, SoC information in order to optimize autonomy instead of performance or vice-versa.
Drive Control
17. M. Pacas, J. Weber, "Predictive direct torque control for the PM synchronous machine," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1350- 1356, Oct. 2005. Full Text Link Abstract : This paper shows that a predictive digital control combined with the principle of direct torque control (DTC) leads to an excellent dynamic behavior of the synchronous machine with surface-mounted permanent magnets and is a real alternative to the classical field-orientated control. The advantages are a DTC control scheme with constant switching frequency and a predictable torque ripple. The settling times of the torque are reduced compared to the classical field-orientated control. The application in servo drives in which the rotor position is always measured can easily be achieved by using a commercial digital signal processor. Numerous simulations and measurements confirm the theoretical work.
18. Zuo Zong Liu, Fang Lin Luo, M.A. Rahman, "Robust and precision motion control system of linear-motor direct drive for high-speed X-Y table positioning mechanism," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1357- 1363, Oct. 2005. Full Text Link Abstract : In this paper, design and implementation of an H/sub /spl infin//-based precision motion control system is presented for a high-speed linear-motor direct-drive X-Y table positioning mechanism in semiconductor wire-bonding applications. The system works with a cascaded robust feedback control, which has an inner loop velocity controller and an outer loop position controller, and an autotuning feedforward compensator. The design aim is to achieve high and consistent tracking performance even in the presence of considerable resonance uncertainties and external disturbances. Toward this aim the velocity controller is designed using H/sub /spl infin// optimization technique, based on reduced-order modeling that considers three significant resonance modes and neglects all other resonance modes having an insignificant amplitude and/or too high frequency. These neglected modes and variations of the three resonance modes from machine to machine (due to manufacturing tolerance) and/or with different operating conditions are taken care of by appropriate additive uncertainty representation in the design phase. The resulting system is validated and implemented with a profile motion of a maximum acceleration of 5.2 g (1g=9.81 m/s/sup 2/) on mass-produced wire bonding machines.
19. Chih-Yi Huang, Chao-Peng Wei, Jung-Tai Yu, Yeu-Jent Hu, "Torque and current control of induction motor drives for inverter switching frequency reduction," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1364- 1371, Oct. 2005. Full Text Link Abstract : In this paper, an indirect field-oriented control (FOC) induction motor (IM) drive with instantaneous current and torque control is presented. This proposed control scheme employs hysteresis current and torque controllers to regulate the stator currents. The torque controller is proposed to serve the current controller so that full advantage of the zero voltage vector can be taken to reduce the switching frequency of the inverter. As a result, the actual stator currents can follow the current references as closely as possible, and the current ripple and torque ripple can be greatly decreased compared with the conventional adaptive pulsewidth modulation control method. To verify the feasibility of the proposed scheme, computer simulations and experiment results demonstrate that the proposed method can obtain a high-performance IM drive system.
20. K.K. Mohapatra, R.S. Kanchan, M.R. Baiju, P.N. Tekwani, K. Gopakumar, "Independent field-oriented control of two split-phase induction motors from a single six-phase inverter," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1372- 1382, Oct. 2005. Full Text Link Abstract : Split-phase (six-phase) induction motor stator windings consist of two sets of three phase windings, which are spatially phase separated by 30 electrical degrees. Due to mutual cancellation of the air gap flux for all the 6n/spl plusmn/1 (n=1,3,5...) order harmonic voltages, called zero sequence components, large harmonic currents are generated in the stator phases. Only the 12n/spl plusmn/1 (n=0,1,2,3...)-order harmonic voltage components contribute toward the air gap flux and electromagnetic torque production in the machine. In this paper, a novel scheme is proposed where two six-phase induction motors are connected in series with proper phase sequence so that the zero sequence component voltages of one machine act as torque and flux producing components for the other. Thus, the two six-phase motors can be independently controlled from a single six-phase inverter. A vector control scheme for the dual motor drive is developed and experimentally verified in this paper.
21. Jiabin Wang, Weiya Wang, G.W. Jewell, D. Howe, "Design of a miniature permanent-magnet generator and energy storage system," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1383- 1390, Oct. 2005. Full Text Link Abstract : The paper describes a methodology for optimizing the design and performance of a miniature permanent-magnet generator and its associated energy storage system. It combines an analytical field model, a lumped reluctance equivalent magnetic circuit, and an equivalent electrical circuit. Its utility is demonstrated by means of a case study on a 15-mW, 6000-r/min generator, and the analysis techniques are validated by measurements on a prototype system.
22. M. Cirrincione, M. Pucci, G. Cirrincione, G.-A. Capolino, "Constrained minimization for parameter estimation of induction motors in saturated and unsaturated conditions," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1391- 1402, Oct. 2005. Full Text Link Abstract : This paper presents the analytical solution of the application of the constrained least-squares (LS) minimization to the online parameter estimation of induction machines. This constrained minimization is derived from the classical linear dynamical model of the induction machine, and therefore it is able to estimated the steady-state value of the electrical parameters of the induction motor under different magnetization levels. The methodology has been verified in simulation with a dynamical model which takes into account iron path saturation effects. After a description of the experimental setup and its signal processing systems, the methodology is verified experimentally under saturated and unsaturated working conditions, and the results are discussed and compared to those obtained with a classical unconstrained ordinary LS technique.
23. Xiaoli Li, R. Du, B. Denkena, J. Imiela, "Tool breakage monitoring using motor current signals for machine tools with linear motors," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1403- 1408, Oct. 2005. Full Text Link Abstract : In recent years, a number of machining centers have been built using linear motors. These machining centers have great potential for precision and high-speed machining. Nevertheless, a number of problems remain unsolved, such as monitoring and control. This paper presents a new tool breakage monitoring method for this type of machining center using the current signal of the linear motor. First, the relationship between the cutting force and the motor current is analyzed. Then, the new tool breakage method is presented. From a mathematical point of view, the new method uses a nonlinear energy operator to capture the abrupt changes of the motor current signal, which is directly related to the tool breakage. The experiment validation is included.
24. D. Casadei, G. Serra, A. Tani, A. Trentin, L. Zarri, "Theoretical and experimental investigation on the stability of matrix converters," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1409- 1419, Oct. 2005. Full Text Link Abstract : Matrix converters perform a direct coupling between two ac sources without the need for energy storage components. This characteristic, together with the presence of L-C input filters and the feedforward compensation of the input voltage variations, may determine unstable operation as the power delivered to the load exceeds a limit value. In this paper, a theoretical analysis of the stability of matrix converters is presented with the aim of predicting possible critical operating conditions. It is verified that all of the system parameters affect more or less the stability, including the delay introduced by the digital controller and the power losses. The theoretical analysis is supported by numerical simulations and experimental results carried out on a matrix converter prototype.
Emerging Technology
25. Woei Wan Tan, Hong Huo, "A generic neurofuzzy model-based approach for detecting faults in induction motors," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1420- 1427, Oct. 2005. Full Text Link Abstract : Many fault detection and diagnosis schemes are based on the concept of comparing the plant output with a model in order to generate residues. A fault is deemed to have occurred if the residue exceeds a predetermined threshold. Unfortunately, the practical usefulness of model-based fault detection schemes is limited because of the difficulty in acquiring sufficiently rich experimental data to identify an accurate model of the system characteristics. This paper aims at developing a generic neurofuzzy model-based strategy for detecting broken rotor bars, which is one of the most common type of faults that may occur in a squirrel-cage induction motor. A neurofuzzy model that captures the generic characteristics of a class of asynchronous motor is the key component of the proposed approach. It is identified using data generated by a simulation model that is constructed using information on the name plate of the motor. Customization for individual motors is then carried out by selecting the threshold for fault detection via an empirical steady-state torque-speed curve. Since data obtained from a practical motor are used to select the threshold and not to build a complete model, the objective of reducing the amount of experimental input-output data required to design a model-based fault detector may be realized. Experimental results are presented to demonstrate the viability of the proposed fault detection scheme.
26. F. Janabi-Sharifi, Jingrong Liu, "Design of a self-adaptive fuzzy tension controller for tandem rolling," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1428- 1438, Oct. 2005. Full Text Link Abstract : A fuzzy logic controller (FLC) is designed to maintain constant tension for tandem rolling mills. Self-adaptive techniques were introduced to optimize the proposed FLC's parameters (i.e., to make it flexible and enable it to generalize). With the inclusion of supervision and concern for generic control criteria, the optimal parameters of the fuzzy inference system were either tuned by a backward propagation algorithm or determined by means of a genetic algorithm. In simulations, the proposed neuro-fuzzy controller exhibited the real-time applicability, while the proposed genetic fuzzy controller revealed outstanding global optimization ability.
27. K. Viswanathan, R. Oruganti, D. Srinivasan, "Nonlinear function controller: a simple alternative to fuzzy logic controller for a power electronic converter," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1439- 1448, Oct. 2005. Full Text Link Abstract : Recently, there has been an increase in the application of fuzzy logic controllers (FLCs) for control of power electronic converters. Due to the FLCs' complex algorithm, their realization often calls for a compromise between cost and performance. In this paper, it is shown that the rule table of most of the two-input FLCs used with power converters can be approximated into a single nonlinearity. This allows the controller to be easily realized using simple, fast, and inexpensive analog circuits. The simplified "nonlinear function controller (NLFC)" developed in this manner is shown to be equivalent in performance to the original FLC through simulations. The NLFC concept is then applied to PI-FLC, a type of FLC popular in power converter control applications. This results in the PI-FLC being replaced by a simple "nonlinear PI controller (NPIC)". Using this simplification, the design of NPICs to obtain good dynamic performance in power converters is explained. An example design of NPIC for controlling a dc-dc boost power converter is presented. Experimental results are also presented to demonstrate the superior dynamic performance of the converter with NPIC versus that of a linear-PI controller.
28. H.M. Gutierrez, P.I. Ro, "Magnetic servo levitation by sliding-mode control of nonaffine systems with algebraic input invertibility," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1449- 1455, Oct. 2005. Full Text Link Abstract : Magnetic Servo Levitation (MSL) is an important actuation principle with potential applications ranging from ultrahigh-precision positioning to high-speed rail systems. This paper describes a nonlinear controller design technique for MSL that has inherent robustness to both parametric uncertainties and unmodeled dynamics. Most of the currently available literature on sliding mode considers nonlinear systems that are linear (affine) in the input action. The proposed technique allows designing sliding-mode controllers for the family of nonaffine problems that have an input nonlinearity algebraically invertible with respect to the available control action. This differs from the standard approach of input feedback linearization, and is based on a modified sliding condition that can be used to synthesize a switching control law. An equivalent control term can also be included, substantially enhancing the performance of the controller. Experimental results show that the proposed technique can achieve excellent tracking at high speeds in a fast-tool servo system actuated by MSL.
Letters To The Editor
29. Juing-Huei Su, Bor-Chin Hsu, "Application of small-gain theorem in the dead-time compensation of voltage-source-inverter drives," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1456- 1458, Oct. 2005. Full Text Link Abstract : A simple and iterative algorithm is devised in this letter with the help of the small-gain theorem to determine the current polarities of pulsewidth-modulation voltage-source-inverter drives. Experimental results are also presented to show the effectiveness of the method when used in the dead-time compensation.
30. K.L. Shi, Hui Li, "Optimized PWM strategy based on genetic algorithms," IEEE Trans. on Industrial Electronics, vol. 52, no. 5, pp. 1458- 1461, Oct. 2005. Full Text Link Abstract : A genetic algorithm is applied to optimize a pulsewidth modulation (PWM) inverter, which cannot only spread harmonic energy but also reduce harmonic distortion. Simulation and experimental results verify that the optimized PWM technique is superior to standard triangular PWM and random PWM techniques.
IEEE Transactions on Industrial Electronics
