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Low cost sensor less starting technique of brushless DC motors
130
Abstracts
121 A n Adaptive Predictive Diagnostic System Based on Fuzzy lhattern Recognition C. Frellcot, B. Dubulsson, pp 565-568 For the automatic monitoring of technological systems, diagnostic systems must be able to recognize the state the system is governed by, quickly and confidently. Furthermore, since some states may be unknown, such diagnostic systems must be able to self-adapt to new situations, i.e. to learn. Pattern-recognition methods may be used for that purpose. Nowadays, however, predictive diagnosis is required in order to prevent an undesirable evolution of the system. This paper presents an adaptive predictive diagnostic system that aims at reaching these requirements. A fuzzy approach is used to realize the learning decision and prediction abilities of the system.
122 Fault Diagnosis by Means of a Predicate Logic Description of the Dynamical Process J. Lunze, F. Schiller, pp 569-572 A method for logic-based fault diagnosis is proposed, based on a qualitative model of the dynamic system. The model has the form of a set of predicate logic formulae. The diagnostic task is solved by a deduction algorithm that reasons from the observations backwards to the faults that have caused the perturbations. Additional information about the causal structure of the dynamic system is utilised to restrict the search space of the deduction system.
123 Diagnosis of Automation Systems on the Base of TimeRelated Petri Nets K. Lemmer, E. Sehnioder, pp 573-576 To avoid unnecessary down-time of technical processes, immediate fault detection is required. Further, an appropriate reaction is necessary. For complex systems, this task can be performed only by on-line monitoring of the process by means of a diagnostic system. In the case of any distortion, exact iocalisation of the possible consequences of the occurring error fault, i.e. isolation, has to be determined. This paper presents a concept for the computer-aided design of a diagnostic system. The diagnostic algorithm is based on a discrete-event model, implemented by means of Petri nets with dwell times.
124 Processing Fault-Trees by Approximate Reasoning in Solving the Technical Diagnostic Problem (A Possibmstic Diagnostic Decision-Makl~ Method) M. Ulleru, pp 577-580 The work may be viewed as a qualitative jump from the use of artificial intelligence techniques to that of fuzzy-logic-based methods in the design of diagnostic expert systems. A symptomsfaults fuzzy interrelational diagnostic model is designed off-line. The diagnostic model is encoded within the knowledge base as a collection of fuzzy if-then rules. The inference mechanism performs on-line diagnosis by adapting the model to the current situation, and then compressing the adapted diagnostic model to a vector containing fault possibilities. The fault candidates with the maximal fault possibilities are considered and validated. The proposed diagnostic methodology is developed on a very simple example for a DC motor.
125 A Methodology of Setting the Purpose of Automation Systems C. Imamlchl, pp 581-584
approach may be called "technocentric". In contrast, the HDZ/KDI, in its research projects, looks as problems with the aim of finding a solution that balances the advantages of a merely technical solution, with the needs and eompetencies of people. Such human-centered systems are developed by interdisciplinary teams integrating junior staff and students from science and engineering, humanities and the social and behavioural sciences. The report describes several projects.
127 Production Islands and Utopian Design: Reasserting the Cultural Dimension R. Badham, pp 589.592 For skill-based design to provide a viable system design alternative to "technocratic" and "lean production" models, it needs to make explicit and further develop its underlying vision and principles. Skill-based design is a basic cultuxal approach to technology and work, adapted to the political and economic conditions. If the cultural roots are ignored, skill-based design becomes indistinguishable from other methods for increasing productivity through increased skills, group work, decentralisation, etc. If this point is ignored, there is a danger of creating, under the guise of humanisation, the very opposite form of work - - a perfect form of disciplined society, visualised in an extreme form by Bentham and Foucault.
128 Automated Informational Flows: Why Human Intervention Is Still Necessary J..P. Durand, pp 593-604 A technological system cannot be separated from its social matrix; designers' preconceived images of labour and of Man's place with regard to matter dearly show through the main c ~ r i s t i c s of automated production. These images can be explained by underlining the way production is characterized by a dissociation between operators (who are interchangeable) and the command and control of the process, which is kept aloof from the shopfloor. Through the concept of socio-technical steps it is possible to formalize the social preconditions for the production of technology. The links between computerisation and capitalism can also be described using the same approach. The social nature of information is considered. 129 Suggested Managerial Approach for Appropriate Automation In Small and Medium Size Firms in Mexico E. Oliva-Lopez, pp 605-609 Work automation is regarded as a key technological resource for the improvement of competitiveness in most organisations. Indeed, automation of critical tasks has become an urgent need for a number of firms in Mexico, who require to increase plant productivity, product quality and safety and welfare levels. Most managers of small and medium-sized firms lack information about the factors determining successful work automation, and social impact and cultural background are only marginally considered, if at all. This paper discusses how appropriate work automation could be implemented in such finns. The role of industrial managers is discussed, and some general iafrastructural requirements are presented. 130 Low Cost Sensor Less Starting Technique of Brushless DC Motors S.K. Chakraborty, p p 611-614
Traditional systems engineering methodology defines requirement definition as the first phase of the whole process. However, cultural aspects of automation should be considered before this phase. This paper summarizes the reasons why cultural aspects of automation should be considered before starting the system design. Then, the process steps of the system's purpose-setting phase are formalized, including the parameters that should be investigated at each step of the process.
Brushless DC motors are usually fitted with hall sensors for rotor position sensing. As the personal computer gets smaller in size, it has become a challenge in the disk drive industry to make the drive unit smaller, so as to maximize the size-to-capacity ratio. BLDC motors are used in the computer disk drive industry and hall sensors take up a sizeable amount of space inside the drive unit. To utilize the available space to its maximum effect, disk drive manufacturers are looking for sensor-less BLDC motors. This paper presents a practical solution to this end.
126 Research Strategies for Human.Centered Design of Human-Machine Systems D. Brandt, pp 585-588
131 Optimal Modification of Reference Signals for Critical Processes Using Alarm Signals A. Hansson, pp 615-618
Recent technological developments seem to show a strong orientation towards finding the best technical solution to a problem; this tends to be automation. Frequently, however, these solutions show little consideration of the people concerned. This
An optimal scheme for the modification of reference signals on the basis of information obtained from alarm signals is proposed. The modification may be interpreted as on open-loop controller from the alarm.
Abstracts
121 A n Adaptive Predictive Diagnostic System Based on Fuzzy lhattern Recognition C. Frellcot, B. Dubulsson, pp 565-568 For the automatic monitoring of technological systems, diagnostic systems must be able to recognize the state the system is governed by, quickly and confidently. Furthermore, since some states may be unknown, such diagnostic systems must be able to self-adapt to new situations, i.e. to learn. Pattern-recognition methods may be used for that purpose. Nowadays, however, predictive diagnosis is required in order to prevent an undesirable evolution of the system. This paper presents an adaptive predictive diagnostic system that aims at reaching these requirements. A fuzzy approach is used to realize the learning decision and prediction abilities of the system.
122 Fault Diagnosis by Means of a Predicate Logic Description of the Dynamical Process J. Lunze, F. Schiller, pp 569-572 A method for logic-based fault diagnosis is proposed, based on a qualitative model of the dynamic system. The model has the form of a set of predicate logic formulae. The diagnostic task is solved by a deduction algorithm that reasons from the observations backwards to the faults that have caused the perturbations. Additional information about the causal structure of the dynamic system is utilised to restrict the search space of the deduction system.
123 Diagnosis of Automation Systems on the Base of TimeRelated Petri Nets K. Lemmer, E. Sehnioder, pp 573-576 To avoid unnecessary down-time of technical processes, immediate fault detection is required. Further, an appropriate reaction is necessary. For complex systems, this task can be performed only by on-line monitoring of the process by means of a diagnostic system. In the case of any distortion, exact iocalisation of the possible consequences of the occurring error fault, i.e. isolation, has to be determined. This paper presents a concept for the computer-aided design of a diagnostic system. The diagnostic algorithm is based on a discrete-event model, implemented by means of Petri nets with dwell times.
124 Processing Fault-Trees by Approximate Reasoning in Solving the Technical Diagnostic Problem (A Possibmstic Diagnostic Decision-Makl~ Method) M. Ulleru, pp 577-580 The work may be viewed as a qualitative jump from the use of artificial intelligence techniques to that of fuzzy-logic-based methods in the design of diagnostic expert systems. A symptomsfaults fuzzy interrelational diagnostic model is designed off-line. The diagnostic model is encoded within the knowledge base as a collection of fuzzy if-then rules. The inference mechanism performs on-line diagnosis by adapting the model to the current situation, and then compressing the adapted diagnostic model to a vector containing fault possibilities. The fault candidates with the maximal fault possibilities are considered and validated. The proposed diagnostic methodology is developed on a very simple example for a DC motor.
125 A Methodology of Setting the Purpose of Automation Systems C. Imamlchl, pp 581-584
approach may be called "technocentric". In contrast, the HDZ/KDI, in its research projects, looks as problems with the aim of finding a solution that balances the advantages of a merely technical solution, with the needs and eompetencies of people. Such human-centered systems are developed by interdisciplinary teams integrating junior staff and students from science and engineering, humanities and the social and behavioural sciences. The report describes several projects.
127 Production Islands and Utopian Design: Reasserting the Cultural Dimension R. Badham, pp 589.592 For skill-based design to provide a viable system design alternative to "technocratic" and "lean production" models, it needs to make explicit and further develop its underlying vision and principles. Skill-based design is a basic cultuxal approach to technology and work, adapted to the political and economic conditions. If the cultural roots are ignored, skill-based design becomes indistinguishable from other methods for increasing productivity through increased skills, group work, decentralisation, etc. If this point is ignored, there is a danger of creating, under the guise of humanisation, the very opposite form of work - - a perfect form of disciplined society, visualised in an extreme form by Bentham and Foucault.
128 Automated Informational Flows: Why Human Intervention Is Still Necessary J..P. Durand, pp 593-604 A technological system cannot be separated from its social matrix; designers' preconceived images of labour and of Man's place with regard to matter dearly show through the main c ~ r i s t i c s of automated production. These images can be explained by underlining the way production is characterized by a dissociation between operators (who are interchangeable) and the command and control of the process, which is kept aloof from the shopfloor. Through the concept of socio-technical steps it is possible to formalize the social preconditions for the production of technology. The links between computerisation and capitalism can also be described using the same approach. The social nature of information is considered. 129 Suggested Managerial Approach for Appropriate Automation In Small and Medium Size Firms in Mexico E. Oliva-Lopez, pp 605-609 Work automation is regarded as a key technological resource for the improvement of competitiveness in most organisations. Indeed, automation of critical tasks has become an urgent need for a number of firms in Mexico, who require to increase plant productivity, product quality and safety and welfare levels. Most managers of small and medium-sized firms lack information about the factors determining successful work automation, and social impact and cultural background are only marginally considered, if at all. This paper discusses how appropriate work automation could be implemented in such finns. The role of industrial managers is discussed, and some general iafrastructural requirements are presented. 130 Low Cost Sensor Less Starting Technique of Brushless DC Motors S.K. Chakraborty, p p 611-614
Traditional systems engineering methodology defines requirement definition as the first phase of the whole process. However, cultural aspects of automation should be considered before this phase. This paper summarizes the reasons why cultural aspects of automation should be considered before starting the system design. Then, the process steps of the system's purpose-setting phase are formalized, including the parameters that should be investigated at each step of the process.
Brushless DC motors are usually fitted with hall sensors for rotor position sensing. As the personal computer gets smaller in size, it has become a challenge in the disk drive industry to make the drive unit smaller, so as to maximize the size-to-capacity ratio. BLDC motors are used in the computer disk drive industry and hall sensors take up a sizeable amount of space inside the drive unit. To utilize the available space to its maximum effect, disk drive manufacturers are looking for sensor-less BLDC motors. This paper presents a practical solution to this end.
126 Research Strategies for Human.Centered Design of Human-Machine Systems D. Brandt, pp 585-588
131 Optimal Modification of Reference Signals for Critical Processes Using Alarm Signals A. Hansson, pp 615-618
Recent technological developments seem to show a strong orientation towards finding the best technical solution to a problem; this tends to be automation. Frequently, however, these solutions show little consideration of the people concerned. This
An optimal scheme for the modification of reference signals on the basis of information obtained from alarm signals is proposed. The modification may be interpreted as on open-loop controller from the alarm.