The paper is concerned with methods of fuzzy clustering based minimization of a scalar performance index with the aid of some labelled patterns. Some modifications of the performance index that take into account the r...
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The paper is concerned with methods of fuzzy clustering based minimization of a scalar performance index with the aid of some labelled patterns. Some modifications of the performance index that take into account the results of partial supervision are proposed. The results of the algorithms introduced are exemplified by the use of numerical examples (Gustafson's cross and EKG data set).
The recently obtained evidence of the need for a positive real element in an adaptive system leaves us with a disturbing gap in adaptive control theory. It is a fact that in some applications adaptive controllers are ...
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The recently obtained evidence of the need for a positive real element in an adaptive system leaves us with a disturbing gap in adaptive control theory. It is a fact that in some applications adaptive controllers are performing well in practice. How can these systems behave well in practical situations which must contain modeling error? This paper introduces a preliminary result which indicates that it may be possible to maintain the needed positive real system in the presence of modeling error. The result shows that if a continuous-time system with large high frequency uncertainty is treated appropriately with antialiasing filters and sampled slowly enough, the resulting discrete-time system may contain very little uncertainty. With small enough uncertainty in the plant, a positive real system in the adaptive loop is possible.
In this paper, two theorems are quoted which, when applied together, provide much information about the robustness of adaptive control schemes. From these two theorems, another theorem is developed which can explain w...
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In this paper, two theorems are quoted which, when applied together, provide much information about the robustness of adaptive control schemes. From these two theorems, another theorem is developed which can explain why adaptive controllers can perform robustly in certain practical situations, while possibly failing in other situations. In particular, if the bandwidth constraints on a control systems are lenient enough to allow the use of a sampling frequency which is smaller than the frequency at which unstructured uncertainty becomes significant, an adaptive controller can behave robustly. Many, if not all, of the applications of adaptive control which have been successful employ relatively slow sampling of the process. Thus, the results of this paper provide a theoretical explanation of how certain adaptive controllers are performing robustly in practice. In addition, the final theorem is of a form which provides insight into what a priori knowledge is required to achieve robust adaptive control and how this knowledge say be used.
The orthogonal collocation approach is now well known to solve, effectively, the state constrained optimal control problems. Mathematical programming technique was also used as an effective tool to construct the optim...
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The orthogonal collocation approach is now well known to solve, effectively, the state constrained optimal control problems. Mathematical programming technique was also used as an effective tool to construct the optimal trajectories. In this paper, a study is done on the efficiency and accuracy requirements of the combined orthogonal collocation and mathematical programming approach, as regarding the employed optimization algorithm, and the number of orthogonal collocation points. It is shown, by experimentation with numerical examples that Fletcher-Powell optimization algorithm is much more faster to produce convergence than Fletcher-Reeves algorithm. The efficiency can be a ratio of six-to-one. The results are compared with an alternative approach to solve the same problem. It is shown that the present algorithm is less costly than the alternative approach, although requiring more computation time. The choice is then a compromise one. As the number of orthogonal points increases, the resulting solutions are more accurate, but the convergence speed decreases. Experimentation with N, shows a save of five-to-one in computing time can be achieved with almost the same cost function. Finally, it is shown, by a numerical example, that uniformly distributed collocation points result in non-optimal solutions, which also violate the problem constraints. It is a numerical proof of the superiority of the orthogonal collocation approach.
The authors discuss the features of the ASRU-8 multiloop microprocessor-based process control station, concentrating on those basic features of the station that make it different from other such stations on the market...
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ISBN:
(纸本)0863410294
The authors discuss the features of the ASRU-8 multiloop microprocessor-based process control station, concentrating on those basic features of the station that make it different from other such stations on the market. The station offers the following advantages: the capability of realizing complex control schemes;the capability of realizing closed-loop control with one and the same ASRU-8 station;and a very simple change of control actions at the time of design, putting into operation, testing, and subsequent use.
The problem of guided missile flight with minimum normal acceleration is investigated. Obtaining an analytical result for the problem in its general form is difficult. A constant normal acceleration policy is obtained...
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The problem of guided missile flight with minimum normal acceleration is investigated. Obtaining an analytical result for the problem in its general form is difficult. A constant normal acceleration policy is obtained which requires keeping the normal acceleration constant all the flight time and satisfying all the constraints. A computer program is prepared and executed using real data to form some charts for different velocities and different missile initial conditions. Comparing the results using the above optimum policy, and the results solving the problem by the gradient technique shows that it gives a less normal acceleration.
Due to the importance of the flight time elapsed of a guided missile before impact, the minimum time flight policy is investigated. Using the maximum principle, the results of bang-bang control policy are given but wi...
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Due to the importance of the flight time elapsed of a guided missile before impact, the minimum time flight policy is investigated. Using the maximum principle, the results of bang-bang control policy are given but with highly complicated costate equations. Some remarks are made about the behaviour of the optimal control policy. Three different numerical algorithms are described and applied to obtain a bang-bang control policy using real data for the missile. The first and second algorithms are based on the remarks obtained from the analytical results. The gradient technique is also used in obtaining the third algorithm. The effects of both the amplitude of the control and the allowable number of switches in the control on the miss distance are obtained. The relation between the target velocity and the final time is also investigated.
The paper presents an effective identification method in fuzzy relational systems. We propose an algorithm for constructing models on the basis of fuzzy and nonfuzzy data with the aid of fuzzy discretization and clust...
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The paper presents an effective identification method in fuzzy relational systems. We propose an algorithm for constructing models on the basis of fuzzy and nonfuzzy data with the aid of fuzzy discretization and clustering techniques. The usefulness of the method provided is demonstrated by means of two numerical examples. Also a possible way of generating a linguistic decision-making algorithm is discussed.
The paper deals with a model of decision‐making given in a form of a fuzzy relational equation with relationships between imprecisely defined goals and constraints modelled by means of a fuzzy relation. The usefulnes...
The paper deals with a model of decision‐making given in a form of a fuzzy relational equation with relationships between imprecisely defined goals and constraints modelled by means of a fuzzy relation. The usefulness of the model and its novelty is clearly pointed out. Some basic problems concerned, e.g. with a construction of the relation of the model and ordering of goals and constraints with respect to their importance (viz. their influence on a fuzzy decision), are also discussed in a detailed manner.
The use of fuzzy logic to control purposes is closely related to implementation of a main scheme of reasoning with fuzzy premises such as generalized modus *** realization by the use of fuzzy relation equations is put...
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The use of fuzzy logic to control purposes is closely related to implementation of a main scheme of reasoning with fuzzy premises such as generalized modus *** realization by the use of fuzzy relation equations is put into exhaustive discussion.
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