Special Section Papers on Distributed
Network-Based Control Systems And Applications
1. Lingfeng Wang, Bin Huang, Kay Chen Tan, "Fault-tolerant vibration control in a networked and embedded rocket fairing system," IEEE Trans. on Industrial Electronics, vol. 51, no. 6, pp. 1127- 1141, Dec. 2004. Full Text Link Abstract : Active vibration control using piezoelectric actuators in a networked and embedded environment has been widely applied to solve the rocket fairing vibration problem. However, actuator failures may lead to performance deterioration or system dysfunction. To guarantee the desired system performance, the remaining actuators should be able to coordinate with each other to compensate for the damaging effects caused by the failed actuator in a timely manner. Further, in the networked control environment, timing issues such as sampling jitter and network-induced delay should be considered in the controller design. In this study, a timing compensation approach is implemented in an adaptive actuator failure compensation controller to maintain the fairing system performance by also considering the detrimental effects from real-time constraints. In addition, time-delay compensation in the networked control system is discussed, which is able to reduce damaging effects of network-induced delays.
2. D.P. Buse, Q.H. Wu, "Mobile agents for remote control of distributed systems," IEEE Trans. on Industrial Electronics, vol. 51, no. 6, pp. 1142- 1149, Dec. 2004. Full Text Link Abstract : A modern distributed industrial system, such as a power transmission system, consists of many sites distributed throughout a wide area. Each site contains a number of monitoring and control devices, also known as intelligent electronic devices, which perform various tasks including condition monitoring, control, and protection. However, apart from dedicated links to the control center for control purposes, substations are often connected by networks with relatively low bandwidth, which makes remote access to these devices for control or monitoring relatively difficult. Therefore, we propose the use of mobile agents for remote access to devices. In this paper, the advantages and disadvantages of the use of mobile agents are evaluated by means of a theoretical model and a series of experiments. The results suggest that for networks with high latency mobile agents may provide performance improvements over more conventional client-server systems.
3. Kyung Chang Lee, Man Ho Kim, Suk Lee, Hong Hee Lee, "IEEE-1451-based smart module for in-vehicle networking systems of intelligent vehicles," IEEE Trans. on Industrial Electronics, vol. 51, no. 6, pp. 1150- 1158, Dec. 2004. Full Text Link Abstract : As vehicles become intelligent for the convenience and safety of drivers, in-vehicle networking (IVN) systems and smart modules are essential components of intelligent vehicles. However, there are obstacles for the wide acceptance of smart modules. First, there exist numerous IVN protocols that a smart module should be able to support. Second, the whole smart module has to be replaced when only the sensor of the module fails. In order to overcome these obstacles, a smart module is implemented as two units; one responsible for network communication and the other for sensor/actuator operations. In addition, the modules use an interface between the two units as defined by the IEEE 1451 standard. This paper presents a design of the smart module based on the IEEE 1451 standard along with the experimental evaluation for time delays.
4. P. Marti, J. Yepez, M. Velasco, R. Villa, J.M. Fuertes, "Managing quality-of-control in network-based control systems by controller and message scheduling co-design," IEEE Trans. on Industrial Electronics, vol. 51, no. 6, pp. 1159- 1167, Dec. 2004. Full Text Link Abstract : In network-based control systems (NCSs), plant sensor-controller-actuator nodes in closed-loop operation drive principal network traffic. The quality-of-control (QoC) in an NCS, i.e., the performance delivered by each closed-loop operation, depends not only on the controller design but also on the message scheduling strategy. In this paper, we show that the co-design of adaptive controllers and feedback scheduling policies allows for the optimization of the overall QoC. First, we discuss the limitations of standard discrete-time control models for controllers of control loops that are closed over communication networks. Afterwards, we describe an approach to adaptive controllers for NCS that: 1) overcomes some of the previous restrictions by online adapting the control decisions according to the dynamics of both the application and executing platform and 2) offers capabilities for dynamic management of QoC through message scheduling.
5. J. Garcia, F.R. Palomo, A. Luque, C. Aracil, J.M. Quero, D. Carrion, F. Gamiz, P. Revilla, J. Perez-Tinao, M. Moreno, P. Robles, L.G. Franquelo, "Reconfigurable distributed network control system for industrial plant automation," IEEE Trans. on Industrial Electronics, vol. 51, no. 6, pp. 1168- 1180, Dec. 2004. Full Text Link Abstract : Use of advanced communication technologies, highly integrated control, and programming platforms drastically increases the performance of industrial control systems. That is the case of Motronic, where the synergistic collaboration between industry and academia has led to an advanced distributed network control system. To be commercially successful, it needs to have a low cost and to be robust, even if this requirement implies that it is a custom design and not based on previously existing commercial solutions. Use of standards and off-the-shelf products lower development costs, but usually raise production costs. In this paper, we show that, in certain applications, design of a new system from scratch is more advantageous. This system comprises a set of dynamically reconfigurable local controller nodes, a graphical programming environment, a remote supervision and control system, and a fault-tolerant fiber optical network. TCP/IP connectivity is provided by the use of a local gateway. Motronic is currently being applied in the integrated control of large production plants and in energy and power management industries.
6. D. Lim, A. Anbuky, "A distributed industrial battery management network," IEEE Trans. on Industrial Electronics, vol. 51, no. 6, pp. 1181- 1193, Dec. 2004. Full Text Link Abstract : This paper discusses a control network organization for industrial battery management. The battery network is logically partitioned into strings containing groups of cells. These groups of cells are managed locally by distributed control nodes that communicate through the local controller area network (CAN). Battery information is communicated to the remote user through TCP/IP. Both CAN and TCP/IP are connected through the gateway database, allowing for transitions from the battery process time and data volume domain into that of the remote user. The system architecture is based on multiple concurrent processes that facilitate necessary battery monitoring and charge management as well as availability of timely interaction with remote users. Autonomy of these processes is encouraged through the distributed data storage organization. Modeling and testing of the proposed architecture reflects the potential capacity for managing battery requirements and network traffic. Scalability of the approach to suit battery network size may also prove useful to serve other similar applications.
7. A. Prayati, C. Koulamas, S. Koubias, G. Papadopoulos, "A methodology for the development of distributed real-time control applications with focus on task allocation in heterogeneous systems," IEEE Trans. on Industrial Electronics, vol. 51, no. 6, pp. 1194- 1207, Dec. 2004. Full Text Link Abstract : A distributed application development methodology is necessary to define specific steps, through which the application specification can be successfully mapped to the system devices. Interoperability and real-timeliness are two major issues in distributed control application development. The main focus of this paper is a generic device model, developed to provide interoperability, and the function block allocation (FBALL) algorithm, defined to guarantee that real-time requirements are met. FBALL is a hybrid approach targeted for the nature of distributed control applications, resulting in an assignment of the application tasks to the system resources, as well as a feasible schedule that meets the real-time constraints. Based on these solutions to interoperability and real-time criticality, a methodology is presented, supporting the distributed control application specification, modeling, and implementation to heterogeneous systems.
8. C. Koulamas, S. Koubias, G. Papadopoulos, "Using cut-through forwarding to retain the real-time properties of Profibus over hybrid wired/wireless architectures," IEEE Trans. on Industrial Electronics, vol. 51, no. 6, pp. 1208- 1217, Dec. 2004. Full Text Link Abstract : The benefits of wireless extensions in industrial networks are well recognized as long as the integration of the wireless and fieldbus domains will be capable of retaining the real-time and dependability quality of the current wired industrial networking solutions. In this paper, the architecture and the operation of a cut-through forwarding device are described, to be used in broadcasting, hybrid wired/wireless Profibus systems. Analytical models of the delay overhead introduced due to frame forwarding are presented. It is shown that the usage of cut-through forwarding devices relaxes the bit-rate requirements in the radio segments, while it drastically improves the inherent advantages and reduces the drawbacks of hybrid transmission media architectures, which are based on a single Medium Access Control domain.
9. Y. Tipsuwan, Mo-Yuen Chow, "Gain scheduler middleware: a methodology to enable existing controllers for networked control and teleoperation - part I: networked control," IEEE Trans. on Industrial Electronics, vol. 51, no. 6, pp. 1218- 1227, Dec. 2004. Full Text Link Abstract : Conventionally, in order to control an application over a data network, a specific networked control or teleoperation algorithm to compensate network delay effects is usually required for controller design. Therefore, an existing controller has to be redesigned or replaced by a new controller system. This replacement process is usually costly, inconvenient, and time consuming. In this paper, a novel methodology to enable existing controllers for networked control and teleoperation by middleware is introduced. The proposed methodology uses middleware to modify the output of an existing controller based on a gain scheduling algorithm with respect to the current network traffic conditions. Since the existing controller can still be utilized, this approach could save much time and investment cost. Two examples of the middleware applied for networked control and teleoperation with IP network delays are given in these two companion papers. Part I of these two companion papers introduces the concept of the proposed middleware approach. Formulation, delay modeling, and optimal gain finding based on a cost function for a case study on DC motor speed control with a proportional-integral (PI) controller are also described. Simulation results of the PI controller shows that, with the existence of IP network delays, the middleware can effectively maintain the networked control system performance and stabilize the system. Part II of this paper will cover the use of the proposed middleware concept for a mobile robot teleoperation.
10. Y. Tipsuwan, Mo-Yuen Chow, "Gain scheduler middleware: a methodology to enable existing controllers for networked control and teleoperation-part II: teleoperation," IEEE Trans. on Industrial Electronics, vol. 51, no. 6, pp. 1228- 1237, Dec. 2004. Full Text Link Abstract : This paper is the second of two companion papers. The foundation for the external gain scheduling approach to enable an existing controller via middleware for networked control with a case study on a proportional-integral (PI) controller for dc motor speed control over IP networks was given in Part I. Part II extends the concepts and methods of the middleware called gain scheduler middleware (GSM) in Part I to enable an existing controller for mobile robot path-tracking teleoperation. By identifying network traffic conditions in real-time, the GSM will predict the future tracking performance. If the predicted tracking performance tends to be degraded over a certain tolerance due to network delays, the GSM will modify the path-tracking controller output with respect to the current traffic conditions. The path-tracking controller output is modified so that the robot will move with the fastest possible speed, while the tracking performance is maintained in a certain tolerance. Simulation and experimental results on a mobile robot path-tracking platform show that the GSM approach can significantly maintain the robot path-tracking performance with the existence of IP network delays.
11. M. Di Santo, A. Vaccaro, D. Villacci, E. Zimeo, "A distributed architecture for online power systems security analysis," IEEE Trans. on Industrial Electronics, vol. 51, no. 6, pp. 1238- 1248, Dec. 2004. Full Text Link Abstract : Phenomena that can compromise power systems operation need to be carefully analyzed in order to evaluate their impact on the security and reliability levels of the electrical networks. The real-time assessment of the system's security and reliability levels, especially under unforeseen contingencies, is known as online power system security analysis. For complex networks this process requires large computational efforts whereas computation times should be less than a few minutes for the information to be useful. To address this problem a distributed architecture based on the Web is proposed. The architecture integrates a network of remotely controlled units distributed in the most critical sections of the electrical network for fields data acquisition and safety check violations, a distributed solution engine for the online analysis of the system security, and a Web-based interface for graphical synoptic and reporting development. The results obtained from an intensive experimentation demonstrate the validity of the architecture and stimulate the enhancement of the solution engine through the use of a computational grid able to dynamically acquire the needed resources.
12. S. Soucek, T. Sauter, "Quality of service concerns in IP-based control systems," IEEE Trans. on Industrial Electronics, vol. 51, no. 6, pp. 1249- 1258, Dec. 2004. Full Text Link Abstract : The popularity of network-based control systems (NBCS) is continuously growing. One of the most intriguing aspects is the transportation of control network data over IP-based networks using accepted standards such as EIA-852. To a large extent the actual quality of control (QoC) in such systems depends on the network timing such as delay and delay jitter. This paper presents a classification of relevant quality of service parameters and identifies application classes. Subsequently, the paper focuses on the effect of delay jitter at a fixed mean delay on the QoC. Two sources of delay jitter are identified in IP-based control systems: 1) network traffic induced and 2) protocol induced. As an example of a simple control loop implemented over an EIA-852-based system we investigate how the induced jitter affects the QoC using a time-discrete simulation model. Conclusions are drawn as to how the findings in the EIA-852 system can be interpreted and extended to a generalized NBCS.
13. N. Ando, P. Korondi, H. Hashimoto, "Networked telemicromanipulation systems "Haptic Loupe"," IEEE Trans. on Industrial Electronics, vol. 51, no. 6, pp. 1259- 1271, Dec. 2004. Full Text Link Abstract : In this paper, "Haptic Loupe" telemicromanipulation systems are proposed. We have developed telemicromanipulation systems that enable human operators to perform micro tasks, such as assembly or manufacturing without stress . These systems are based on a scaled bilateral teleoperation system between different structures. The systems are composed of an original six-degrees-of-freedom (6-DOF) parallel link manipulator to carry out micromanipulation and a 6-DOF haptic interface with force feedback. A parallel mechanism is adopted as a slave micromanipulator because of its good features of accuracy and stiffness. The haptic master interface is developed for micromanipulation systems. Haptic device system modeling and a model reference adaptive controller are implemented to compensate for friction forces, which spoil the free motion performance and force response isotropy of the system. Total system performance as a telemicromanipulator system is evaluated by performing some primitive manipulation tasks in a teleoperation experiment. Experimental results are presented and discussed.
14. H. Takahashi, H. Nishi, K. Ohnishi, "Autonomous decentralized control for formation of multiple mobile robots considering ability of robot," IEEE Trans. on Industrial Electronics, vol. 51, no. 6, pp. 1272- 1279, Dec. 2004. Full Text Link Abstract : The purpose of this study is to control multiple mobile robots in formation considering the ability of a robot using the "Leader-Following" strategy. There are three features of this study. First, a performance index that shows mobile robot ability is quantified. Specifically, maximum acceleration and maximum velocity of a robot are defined by maximum admissible rotation and maximum continuous torque of a motor. The performance index is quantified from arrival time on the destination using these parameters. Second, a new controller is proposed based on the performance index, so that robots can be controlled according to robot ability. Third, a compliance controller using a virtual repulsion is suggested in this paper, so that each robot can avoid collision. Finally, simulation and experiments are done in a real-time system using RT-Messenger. RT-Messenger allows robots to transmit information regarding their positions to each other in real time. These results shows the validity of the proposed method.
Power Electronics
15. O. Ojo, "The generalized discontinuous PWM scheme for three-phase voltage source inverters," IEEE Trans. on Industrial Electronics, vol. 51, no. 6, pp. 1280- 1289, Dec. 2004. Full Text Link Abstract : This paper presents analytical techniques for the determination of the expressions for the modulation signals used in the carrier-based sinusoidal and generalized discontinuous pulse-width modulation schemes for two-level, three-phase voltage source inverters. The proposed modulation schemes are applicable to inverters generating balanced or unbalanced phase voltages. Some results presented in this paper analytically generalize the several expressions for the modulation signals already reported in the literature and new ones are set forth for generating unbalanced three-phase voltages. Confirmatory experimental and simulation results are provided to illustrate the analyses.
16. In-Dong Kim, Eui-Cheol Nho, Heung-Geun Kim, Jong Sun Ko, "A generalized Undeland snubber for flying capacitor multilevel inverter and converter," IEEE Trans. on Industrial Electronics, vol. 51, no. 6, pp. 1290- 1296, Dec. 2004. Full Text Link Abstract : This paper proposes a snubber circuit for a flying capacitor multilevel inverter and converter. It also explains the concept of constructing a snubber circuit for a multilevel inverter and converter. The proposed snubber circuit makes use of an Undeland snubber as a basic snubber unit, and thus can be regarded as a generalized Undeland snubber for a flying capacitor multilevel inverter and converter. It has such an advantage of Undeland snubber used in the two-level inverter. Compared with a conventional RLD/RCD snubber for multilevel inverter and converter, the proposed snubber keeps such good features as fewer number of components, reduction of voltage stress of main switching devices due to low overvoltage, and improved efficiency of system due to low snubber loss. In this paper, the proposed snubber is applied to a three-level flying capacitor inverter, and its features are in detail demonstrated by computer simulation and experimental result.
17. A. Sangswang, C.O. Nwankpa, "Noise characteristics of DC-DC boost converters: experimental validation and performance evaluation," IEEE Trans. on Industrial Electronics, vol. 51, no. 6, pp. 1297- 1304, Dec. 2004. Full Text Link Abstract : The purpose of this paper is to quantify existing random noise in a pulse-width modulated (PWM) switching DC-DC boost converter. A DC-DC boost converter performance under the influence of random noise is studied. We experimentally verify the existence of noise and measure its statistical properties on the operating characteristics of the boost converter. A converter model that captures the effect of these inherent random noises on the overall behavior of a practical converter is presented. Existing disturbances are lumped and modeled as switching time uncertainties. We also propose a performance index quantifying the converter performance. This index is known as mean first passage time (MFPT). Comparison between this stochastic performance index, MFPT, and a deterministic counterpart, critical energy, under the presence of realistic disturbances is presented.
18. S.C.O. Mathuna, P. Byrne, G. Duffy, W. Chen, M. Ludwig, T. O'Donnell, P. McCloskey, M. Duffy, "Packaging and integration technologies for future high-frequency power supplies," IEEE Trans. on Industrial Electronics, vol. 51, no. 6, pp. 1305- 1312, Dec. 2004. Full Text Link Abstract : This paper reviews data from the International Technology Roadmap for Semiconductors to establish where dc-dc converters are headed in the first decade of the new millennium. It focuses on the high performance computing (high current, fast response, high power density) and portable/handheld (low profile) sectors. Magnetics and power device packaging technologies needed to allow power supplies to move to operating frequencies in the 1-10 MHz region are discussed. It introduces the concept of magnetic components fully embedded (windings and core) in PCB and silicon offering low profile and low losses at high frequency. It also reviews developments in wirebond-free power packaging such as flip-chip assembly that offer low profile, reduced parasitics and increased thermal performance. Finally, consideration is given to the changes in the power electronics industry that may need to be addressed to enable these new technologies to play a strategic role.
19. Tzu-Yen Chang, Xu Wang, D.A. Evans, S.L. Roberson, J.P. Zheng, "Characterization of tantalum oxide-ruthenium oxide hybrid capacitors," IEEE Trans. on Industrial Electronics, vol. 51, no. 6, pp. 1313- 1317, Dec. 2004. Full Text Link Abstract : The ac and dc performance and leakage current of Evans tantalum oxide-ruthenium oxide hybrid capacitors were characterized at room temperature. The RC time constants were in the range from 2 to 0.45 ms and dependent on the maximum operational voltage of the capacitor. The gravimetric and volumetric energy densities of hybrid capacitors were in the range of 0.074-0.233 J/g and 0.388-1.384 J/cm/sup 3/, respectively. The gravimetric and volumetric power densities of hybrid capacitors were in the range of 19-259 W/g and 100-1540 W/cm/sup 3/, respectively. A comparison of the performance between hybrid capacitors to conventional aluminum and tantalum electrolytic capacitors is made in this paper.
Drive Control
20. M. Hinkkanen, J. Luomi, "Stabilization of regenerating-mode operation in sensorless induction motor drives by full-order flux observer design," IEEE Trans. on Industrial Electronics, vol. 51, no. 6, pp. 1318- 1328, Dec. 2004. Full Text Link Abstract : This paper deals with the full-order flux observer design for speed-sensorless induction motor drives. An unstable region encountered in the regenerating mode at low speeds is well known. To remedy the problem, a modified speed-adaptation law is proposed. Instead of using only the current estimation error perpendicular to the estimated flux, the parallel component is also exploited in the regenerating mode. Using current estimation error loci in steady state, a linearized model, simulations, and experiments, it is shown that the observer using the proposed speed-adaptation law does not have the unstable region. It is also shown that the effect of erroneous parameter estimates on the accuracy of the observer is comparatively small.
21. G. Poddar, V.T. Ranganathan, "Direct torque and frequency control of double-inverter-fed slip-ring induction motor drive," IEEE Trans. on Industrial Electronics, vol. 51, no. 6, pp. 1329- 1337, Dec. 2004. Full Text Link Abstract : A novel sensorless scheme for direct torque and frequency control of a double-inverter-fed slip-ring induction motor is presented. The analysis of a double-inverter-fed induction motor is given to derive the proposed controller. Various frequency profiles are analyzed for a direct frequency controller. A novel frequency profile is suggested to make the sensorless drive operation reliable and machine parameter independent at any rotor speed. Simulation and experimental results are presented from a 50-hp drive, demonstrating that the drive can deliver full torque from 0 to 2-p.u. speed in either direction. Thus, double the rated power can be extracted from the motor without overloading it.
22. M.A. Jabbar, A.M. Khambadkone, Guo Chun, "Quasi-resonant-converters-based high-efficiency spindle motor drives for magnetic data storage," IEEE Trans. on Industrial Electronics, vol. 51, no. 6, pp. 1338- 1343, Dec. 2004. Full Text Link Abstract : Disk drive spindle motors require accurate speed control and highly efficient drive controllers. Small-volume and high-efficiency converters are of particular interest for portable data storage applications. Quasi-resonant voltage controllers are described in this paper and the experimental results are presented. In contrast to the conventional pulsewidth-modulated voltage controller, this technique reduces the switching loss and enables the controller to operate at very high frequencies. Three types of resonant converters are built and tested for the application. A comparison of performance in terms of losses and voltage regulation is given.
Letters To The Editor
23. Liang-Rui Chen, "PLL-based battery charge circuit topology," IEEE Trans. on Industrial Electronics, vol. 51, no. 6, pp. 1344- 1346, Dec. 2004. Full Text Link Abstract : In this paper, a phase-locked battery charger (PLBC) is proposed to show that a phase-locked loop (PLL) is a perfect circuit topology for battery charging. The circuit topology of the PLBC is almost the same as that of the PLL and it inherits the merits of the PLL, such as autotracking, autolocking, and high accuracy. A complete charging process, consisting of three subprocesses: constant current charge, variable current charge, and float charge, can be automatically implemented by using the above inherent characteristics of the PLL. Experimental results show that the PLL is really suitable for carrying out a battery charge controller.
24. L.S. Kei, K. Sridharan, T. Srikanthan, "Hardware-efficient schemes for logarithmic approximation and binary search with application to visibility graph construction," IEEE Trans. on Industrial Electronics, vol. 51, no. 6, pp. 1346- 1348, Dec. 2004. Full Text Link Abstract : Visibility graphs constitute a useful data structure for environment representation in the context of robot path planning. A central element in the construction of the basic visibility graph and its variants is tangent determination. This letter presents new schemes and hardware designs for key elements in tangent construction and identification of obstructed tangents. The designs have been synthesized using Synopsys Design Compiler 2001.08-SP1, and results show they are appropriate for development of a cost-effective and efficient visibility graph generation system.
IEEE Transactions on Industrial Electronics
