A fault detection and isolation scheme for a brushless DC motor driving a mechanical actuation system is presented. First, a detailed mathematical model of the drive is derived. The residual generator is based on pari...
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A fault detection and isolation scheme for a brushless DC motor driving a mechanical actuation system is presented. First, a detailed mathematical model of the drive is derived. The residual generator is based on parity relations while the fault isolation part is implemented by means of the transferable belief model. The problem of distinguishing between faults with the same fault signatures is addressed. It is shown that additional improvements in terms of resolution can be achieved by employing parameter estimation. The proposed FDI scheme is tested on the actual drive under various faults. The achieved performance features the highest resolution, diagnostic stability and accuracy.
Various aspects of dynamical systems with switches are studied. The two concepts “higher-order sliding” and “fast sliding” are defined and a result for stability of second order sliding is given. The linear case i...
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Various aspects of dynamical systems with switches are studied. The two concepts “higher-order sliding” and “fast sliding” are defined and a result for stability of second order sliding is given. The linear case is described in particular detail. Several examples illustrate the results.
Discrete-time symmetric polynomial equations with complex coefficients are studied in the scalar and matrix case. New theoretical results are derived and several resolution algorithms ares proposed and evaluated. The ...
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Discrete-time symmetric polynomial equations with complex coefficients are studied in the scalar and matrix case. New theoretical results are derived and several resolution algorithms ares proposed and evaluated. The algorithms are implemented in the Polynomial Toolbox for Matlab.
The problem of robust controller design is addressed for a single-input single-output plant with a single uncertain parameter. Given one controller that stabilizes the nominal plant, the Youla-Kucera parametrization o...
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Two algorithms are proposed for evaluating the rank of an arbitrary polynomial matrix. They rely upon constant matrix rank evaluations and therefore are more reliable than already existing elementary polynomial operat...
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Two algorithms are proposed for evaluating the rank of an arbitrary polynomial matrix. They rely upon constant matrix rank evaluations and therefore are more reliable than already existing elementary polynomial operations techniques. Some applications are mentioned, such as polynomial null-space extraction or conditions of existence of solutions to matrix polynomial equations arising in control problems. Deux algorithmes sont proposés pour évaluer le rang d'une matrice polynomiale quelconque. Ils sont basés sur des évaluations de rangs de matrices constantes et sont donc plus fiables que les techniques déjà existantes d'opérations polynomiales élémentaires. Quelques applications sont mentionnées, comme l'extraction du noyau polynomial ou des conditions d'existence de solutions aux équations polynomiales matricielles provenant de problèmes de commande.
To reduce the difficulties involved in choosing an appropriate fuzzy knowledge base, i.e. scaling factors, membership functions, rules, etc., of a fuzzy PI controller that is capable of control in most industrial envi...
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ISBN:
(纸本)0780342534
To reduce the difficulties involved in choosing an appropriate fuzzy knowledge base, i.e. scaling factors, membership functions, rules, etc., of a fuzzy PI controller that is capable of control in most industrial environments, a kind of fuzzy controller with a hierarchical structure is proposed which takes accumulated control as an input in addition to the error and change of error. The new fuzzy controller is divided into several subcontrollers which can be designed separately. Each subcontroller can be designed easily and can perform well in a certain running state. When all the subcontrollers perform well, the hierarchical fuzzy controller can obtain a good performance. A general strategy for dividing up the whole controller is defined. Simulation results show that both the transitory performance and the steady-state performance are better than that of conventional fuzzy PI controllers. The proposed hierarchical fuzzy controller is applied to a 10 tonne/hour coal-burning grate boiler and some real-time running results are given.
The evaluation of contaminant concentrations in ground water and soil is an essential aspect of most hazardous waste remedial investigations. This paper describes methods applied toward obtaining, preserving, and anal...
The evaluation of contaminant concentrations in ground water and soil is an essential aspect of most hazardous waste remedial investigations. This paper describes methods applied toward obtaining, preserving, and analyzing subsurface samples for the determination of VOC concentrations in the saturated region of an unconfined coastal plain aquifer at Dover Air Force Base (DAFB), Delaware. The described protocol involved headspace-free subsampling of cores, field preservation of subsamples in methanol, and overnight extraction of the VOCs at elevated temperature (70 degrees C). Methanol-extracted compounds were subsequently transferred to hexane and analyzed by gas chromatography. The method was found to achieve quantitative extraction from the aquifer sands in a single step, although extraction from fine-grained and more strongly sorbing aquitard samples required multiple methanol extractions to achieve comparable recovery. An extensive set of DAFB results is presented as an indication of how these methods can be applied toward characterizing field-scale contamination with a high degree of resolution and accuracy. These data have enabled a quantitative estimate of the contaminant distribution at this site and offer valuable insight into processes of contaminant migration into the underlying aquitard. In these regards, the methods used are believed to have provided much more accurate results than could have been obtained using more commonly applied techniques.
The objectives of Human engineering (HE) are generally viewed as increasing human performance, reducing human error, enhancing personnel and equipment safety, and reducing training and related personnel costs. There a...
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The objectives of Human engineering (HE) are generally viewed as increasing human performance, reducing human error, enhancing personnel and equipment safety, and reducing training and related personnel costs. There are other benefits that are thoroughly consistent with the direction of the Navy of the future, chief among these is reduction of required numbers of personnel to operate and maintain Navy ships. The Naval Research Advisory Committee (NRAC) report on Man-Machine technology in the Navy estimated that one of the benefits from increased application of man-machine technology to Navy ship design is personnel reduction as well as improving system availability, effectiveness, and safety The objective of this paper is to discuss aspects of the human engineering design of ships and systems that affect manning requirements, and impact human-performance and safety The paper will also discuss how the application of human engineering leads to improved performance, and crew safety, and reduced workload, all of which influence manning levels. Finally, the paper presents a discussion of tools and case studies of good human engineering design practices which reduce manning.
In this letter, we study the use of adaptive controllers to maintain the synchronization of two Chua's oscillators when the channel and circuit parameters are time-varying. We present both computer simulation resu...
In this letter, we study the use of adaptive controllers to maintain the synchronization of two Chua's oscillators when the channel and circuit parameters are time-varying. We present both computer simulation results and physical experimental results to verify the operation of the designs.
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