Segmentation of the vascular system from Magnetic Resonance Angiography (MRA) volumetric data is still a challenging problem. Level set evolution methods combine global smoothness with the flexibility of topology chan...
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This paper presents a novel robust sliding mode controller with fuzzy tuning for Stewart Platform servo system, which suffers from high nonlinear dynamics and serious load coupling among channels. The controller consi...
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ISBN:
(纸本)0780393953
This paper presents a novel robust sliding mode controller with fuzzy tuning for Stewart Platform servo system, which suffers from high nonlinear dynamics and serious load coupling among channels. The controller consists of an equivalent control to assign desired dynamics to the closed-loop system, a switching control to guarantee a sliding mode, and a fuzzy control to enhance fast tracking and attenuate chattering. To verify the potential and effectiveness of the proposed controller, simulations and experiments are made. The results demonstrate its strong robustness against a large range of parameters variations and load disturbance and its capability of restraining the serious load coupling among channels and improving the trajectories tracking performance.
The initial motivation of the lifting technique is to solve the H∞control problems. However, the conventional weighted H∞design does not meet the conditions required by lifting, so the result often leads to a misjud...
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The initial motivation of the lifting technique is to solve the H∞control problems. However, the conventional weighted H∞design does not meet the conditions required by lifting, so the result often leads to a misjudgement of the design. Two conditions required by using the lifting technique are presented based on the basic formulae of the lifting. It is pointed out that only the H∞disturbance attenuation problem with no weighting functions can meet these conditions, hence, the application of the lifting technique is quite limited.
This paper presents a novel clustering algorithm for the structure learning of fuzzy neural networks. Our novel clustering algorithm uses the reward and penalty mechanism for the adaptation of the fuzzy neural network...
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In this paper, a sufficient condition is presented to ensure the complete stability of a cellular neural networks (CNNs) that output functions are a set of piecewise sigmoid nonlinear functions. The convergence theore...
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A type of high-order integral observers for matrix second-order linear systems is proposed on the basis of generalized eigenstructure assignment via unified parametric approaches. Through establishing two general para...
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A type of high-order integral observers for matrix second-order linear systems is proposed on the basis of generalized eigenstructure assignment via unified parametric approaches. Through establishing two general parametric solutions to this type of generalized matrix second-order Sylvester matrix equations, two unified complete parametric methods for the proposed observer design problem are presented. Both methods give simple complete parametric expressions for the observer gain matrices. The first one mainly depends on a series of singular value decompositions, and is thus numerically simple and reliable; the second one utilizes the fight factorization of the system, and allows eigenvalues of the error system to be set undetermined and sought via certain optimization procedures. A spring-mass-dashpot system is utilized to illustrate the design procedure and show the effect of the proposed approach.
Eigenstructure assignment using the proportional-plus-derivative feedback controller in a class of secondorder dynamic system is investigated. Simple, general, complete parametric expressions for both the closed-loop ...
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Eigenstructure assignment using the proportional-plus-derivative feedback controller in a class of secondorder dynamic system is investigated. Simple, general, complete parametric expressions for both the closed-loop eigenvector matrix and the feedback gains are established based on two simple Smith form reductions. The approach utilizes directly the original system data and involves manipulations only on n-dimensional matrices. Furthermore, it reveals all the degrees of freedom which can be further utilized to achieve additional system specifications. An example shows the effect of the proposed approach.
This paper exhibits the connection between fuzzy inference system and kernel machines, and proposes a support vector learning approach to construct fuzzy inference system so that it can have good generalization abilit...
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ISBN:
(纸本)0780393953
This paper exhibits the connection between fuzzy inference system and kernel machines, and proposes a support vector learning approach to construct fuzzy inference system so that it can have good generalization ability in a high dimensional feature space. It is showed that the two seemingly unrelated research areas, fuzzy inference systems and kernel machines, are closely related. Under some minor constrains, the equivalence of the two seemingly quite distinct models is proved. The designed fuzzy inference system can be represented as a decision function consisting of series expansion of modified fuzzy basis functions (MFBFs), and this also makes itself to be interpretable. The approach preserves advantages of both the statistical learning framework and the fuzzy inference system. The performance of the proposed approach is illustrated by an example of nonlinear function regression.
This paper presents an investigation into development of feed-forward and feedback control strategies for active vibration suppression and attitude control of flexible spacecrafts. The feed-forward loop consists of a ...
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ISBN:
(纸本)0780393953
This paper presents an investigation into development of feed-forward and feedback control strategies for active vibration suppression and attitude control of flexible spacecrafts. The feed-forward loop consists of a computed-torque scheme and a command shaping technique based on component synthesis vibration suppression (CSVS) method. For relaxing the requirements of dynamic linearity in traditional input component command in CSVS method, a new approach is developed for designing the input component command by utilizing a structure in which the modal forces of flexible modes vibration are shaped according to a predefined trajectory, which improves the performance of CSVS method in vibration suppression for the nonlinear attitude dynamics. On the other hand, to follow the predefined trajectory identically or at least as closely as possible, a model-independent feedback control loop is proposed, which can accomplish further reduction of the residual vibration of flexible appendages. Numerical simulations demonstrate the effectiveness of the control strategy.
This paper presents a class of adaptive ant colony optimization algorithm and proves its convergence properties. The global searching and convergence ability are improved by adaptively changing the pheromone trails ev...
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