Self-Commissioning of Induction Motor Drives

Prof. G. Buja, University of Padova, Italy
Prof. R. Menis, University of Trieste, Italy

 Abstract: PWM inverter-fed induction motor drives exhibit high static and dynamic performance only if their control system is tuned with the motor. Traditionally, tuning has been done either in the factory with a specific motor or at the installation site. The first solution obliges the users to purchase the motor utilized in the factory whilst the second one is time-consuming and needs the employment of skilled personnel. To overcome these disadvantages, modern induction motor drives are endowed with a capability, termed self-commissioning, that automatically tunes the control system with the connected motor. Self-commissioning is arranged in two stages which are identification of the motor parameters and setting of the control system in accordance with the values found for the motor parameters. While the setting stage consists of elementary mathematical operations, the identification stage is much more complex and involves solicitation of the motor with appropriate signals and processing of the responses by means of suitable algorithms. This tutorial is devoted to the identification of the parameters of an induction motor for self-commissioning purposes. It starts by reviewing the role of motor parameters in tuning the control system of high-performance drives such as the field-oriented ones. Then the basic demands for the identification procedure, i.e. use of the inverter for soliciting the motor, no employment of extra sensors and -often- standstill operation of the motor, are introduced together with their effects on the identification procedure. Afterwars the three relevant identification techniques, namely the transient response, the frequency response, and the time-periodic response, are analyzed from both a theoretical and an experimental point of view. The identification of the magnetizing characteristic, required in the field-weakening operation of the drives, is also discussed. At last, the identified parameters are compared with those calculated from the nominal data of the motor and with those found from the conventional no-load and blocked-rotor tests.
 
 

Emerging Multimedia Communication for Industrial Applications

Prof. J. D. Irwin, Auburn University, USA

Abstract: The drive toward affordable, high-speed communication networks together with the advent of emerging multimedia communication technologies will enable numerous industrial applications. However, this technology is changing so rapidly that it is an enormous challenge to design, manage and upgrade the networks to satisfy the demands of modern industry.
This talk will address the fundamental and practical issues that are involved in multimedia communication for the industrial environment. The emerging video, audio and data communication technologies that can be employed in conjunction with local area networks and the Internet will be presented and discussed. In addition, a number of examples will be provided to demonstrate the manner in which today's rapidly evolving networks and multimedia technologies are being employed to meet the ever-growing needs of industry.
 
 

Mechatronics: Teleservice and the Development of Machinery

Prof. Dr.-Ing. Paul Drews, European Centre for Mechatronics, GERMANY

Abstract: Increasing demands on the availability of machines, complex products and functions, inefficient personnel planning and product liability call for new engineering and service strategies. Service will become in fact one of the most important factors in the near future. New business fields will be achieved by developing old-fashioned service concepts towards new ones which can be described as system oriented customer care. This kind of service features lifecycle support as well as process support and function oriented customer support.
Integration of new technologies in terms of sensor systems and machine controllers enables the manufacturer as well as the customer to implement new functionalities in machines and processes. “Design for service” is a demand on manufacturers and suppliers to implement these features already in the design phase of a product. The future development will force the application of microelectronics, computer and communication technologies at machine level. Additional costs of newly implemented components will be worth-while if through adequate organizational support the return on investment for both, the manufacturer and the customer can be estimated in short time scales. In addition, this leads to a new quality management, which affects all parties involved in service. Quality assurance cycles are the key to an ongoing integration of service aspects into the market of high-tech machinery

Sound in the 21st Century

Edward Y. Chen, AT&T Laboratories, USA

Abstract: Perceptual audio coding algorithm is a key element in emerging technology for digital audio. The algorithm has provided the capability of compressing compact disc (CD) stereo audio at 1,406 kbits/sec into rates approximating in the range of 32 to 128 kbits/sec. The capability has enabled developments and provided powerful solutions for many new classes of applications in audio transmission, broadcasting, and storage. In exploring the opportunities provided by these applications, rapid progress is occurring in three related technologies: signal processing and computing, for the creation of the internet music delivering; broadcasting communication, for reliable transmission of CD-quality compressed audio over radio channels; and memory to supplement or replace the magnetic and optical media currently used to store high-quality audio programs. A detail description of an application in Digital Audio Broadcasting (DAB) using such coding algorithm is given.
In recent years, DAB having transmission formats ranging from terrestrial, cable, and satellite has demonstrated to be a powerful and timely technology through various tests. It is seen by many as the logical progression in sound transmission for the next century. The fundamental properties of DAB have been shown to exhibit superb sound quality and a better immunity to interference. It also offers the potential of many new services including digital information services and messaging services that can be easily implemented into DAB technology. In this talk (several pieces of the CD-quality DAB recording from the actual DAB transmission will be demonstrated during the talk), I will describe a Digital Audio Broadcasting system which was developed at AT&T Laboratories, and an ongoing process for creating a Digital Audio Broadcasting standard in the United States.

Networked Intelligent Autonomus Mobile Robot: Issues and Opportunities

Prof. R. C. Luo, National Chung Cheng University, Taiwan, R.O.C.

Abstract: A truly intelligent autonomous mobile robot should have a common representation model which can simutaneously satisfy low level navigational capabilties, medium level self-referencing capabilities, high level motion planning capabilities and the ability to be controlled through Internet. In this  resentation, the issues for a truly intelligent autonomous mobile robot will first be addressed. The issues for supervisory control of an intelligent autonomous mobile robot through Internet will also be discussed. Finally, the opportunities for the application of intelligent autonomous mobile robot will be described. Video presentation to demonstrate the feasibilty of these technics is also included.
 
 

Abstracts of Tutorials
 
 

Computational Intelligence for the Robotics and Automation

Prof. Toshio Fukuda, Nagoya University, Nagoya, Japan

Abstract: This tutorial gives the idea of the Computational Intelligence and the applications to the robotics and automation. First the basics for the computational intelligence is introduced, including the Neural Networks, Fuzzy System and Evolutionary computation, and then the advanced methodologies are shown in detail. Then the application examples will be given how they can improve the conventional methods and how they can solve the problems in the field of the intelligent system of robotics and automation. Moreover the comparison will be shown among those methods.
 

Power Electronics and Drives - Technology Advances and Trends

Prof. Bimal K. Bose, University of Tennessee, Knoxville, USA

Abstract: The technology of power electronics and variable frequency drives has gone through intense evolution in the recent years, and it is now finding widespread acceptance in applications, such as dc and ac power supplies, lighting and welding control, electrochemical processes, filtering and VAR compensation, pump and fan drives, steel and paper mill drives, servo and machine tools drives, robotics, elevators, and transportation systems. Very recently, another dimension of its importance is being visible, that is energy conservation and environmental pollution control. In the global industrial automation, energy conservation and environmental pollution control trends of the 21st century, the widespread impact of power electronics and drives is inevitable. The evolution of power electronics and drives has been possible by many innovations in power semiconductor devices, power conversion techniques, microprocessors and digital signal processors, application specific ICs, personal computers, advanced simulation on CAD tools, and advancement of control and estimation techniques. More recently, intelligent control techniques, such as expert system, fuzzy logic, neural network and genetic algorithm are further extending the frontier of this technology. The complex and interdisciplinary nature of the field is being a real challenge to the engineers.
The presentation will start with an introduction that will give perspective of the technology, which will emphasize its importance in industrial automation, energy, saving and environmental pollution control. The recent advances of the devices, particularly IGBT and MCT will be reviewed, and future potential of SiC and diamond materials will be discussed. The converter technology with particular emphasis of the potential of soft-switched converters will be reviewed. The recent advances and future trends of devices, converters, machines, DSPs, control and estimation techniques will be widely reviewed giving examples of application. Fuzzy logic and neural network based intelligent control will be discussed giving examples of application. Finally, perspective of the 21st century trend will be discussed.
 

Neuro-Fuzzy Approaches for Identification and Control of Nonlinear Systems
 

Prof. Okyay Kaynak, Bogazici University Istanbul, TURKEY

Abstract: Neural Networks and Fuzzy Inference Systems are becoming well-recognized tools of designing a controller capable of perceiving the operating environment and imitating a human operator with high performance. The motivation behind the use of neuro-fuzzy approaches is based on the complexity of real life systems, ambiguities on sensory information or time varying nature of the system under control. In this respect, neuro-fuzzy control approaches combine architectural (by neural networks) and philosophical (by fuzzy systems) aspects of an expert resulting in an artificial brain, which is to be used as a controller.
It is known that the fuzzy inference systems and neural networks are universal approximators. An architecture with an appropriate learning strategy can teach any mapping to such a system with a predefined realization error bound. The most questionable quality in the use of neuro-fuzzy control architectures is the stable training. This tutorial considers various neuro-fuzzy controller structures and training procedures for the identification and control of nonlinear systems. Consideration is given to stabilization of training dynamics. The tutorial concludes with some application examples.
 

Sliding Modes Applications in Motion Control Systems and Power Electronics
 

Prof. Vadim Utkin, Ohio State University, Columbus, USA
Prof. Asif Šabanovic, B.H. Engineering and Consulting Co., Istanbul, Turkey

Abstract: The Variable Structure Systems and particularly Sliding Modes Control attracts a lot of attention for applications in Motion Control and Power Electronics due to their inherent ability to deal with discontinuos control actions, which is common in these two fields. But, like in many other cases, the methods of Sliding Modes Control are, sometimes, without careful design evaluation, applied to the systems with discrete-time and inherently continuous control, like in robotic manipulators control with torques taken as the control inputs. In these cases, due to the inappropriate formulation of the control system design, high frequency chattering occurs. Many such works are reported in the literature, and many different ideas are alleviated to avoid the chattering. But, surprisingly, majority of the proposed solutions does not question the selected framework, or the applied design methods, but deal with consequences with more or less success.
A digital implementation of the control algorithms rises another question. In sliding mode systems tends to have high frequency switching of the control which leads to the very high demands on the calculation speed of the controller. Sometimes low frequency oscillations occur. Appropriate selection of the controller's structure can size down these demands in considerably.
The objective of this Tutorial is
- to address selected theoretical results in the Variable Structure Systems;
- to present the application of sliding modes in switching power converters
- to present the application of sliding modes in motion control systems with discontinuous control (electrical machines)
- to present the application of sliding modes in motion control systems with continuous control (robotics)