Recently, in the area of pattern recognition, the concept of combining multiple support vector machines (SVMs) has been proposed as a new direction to improve classification performance. However, current commonly used...
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Recently, in the area of pattern recognition, the concept of combining multiple support vector machines (SVMs) has been proposed as a new direction to improve classification performance. However, current commonly used SVMs aggregation strategies do not evaluate the importance of degree of the output of individual component SVM classifier to the final decision. A method for multiple SVMs combination using fuzzy integral is proposed to resolve this problem. Fuzzy integral combines objective evidence, in the form of a SVM probabilistic output, with subjective evaluation of the importance of that component SVM with respect to the final decision. The experimental results confirm the superiority of the presented method to the traditional majority voting technique.
Applied to the surface rendering, the marching cubes method shows a great promise for surface extraction by using the surface configurations of a cube. But the marching cubes method has some disadvantages, that come f...
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Applied to the surface rendering, the marching cubes method shows a great promise for surface extraction by using the surface configurations of a cube. But the marching cubes method has some disadvantages, that come from the use of surface configurations of cubes and further restrict the application of this method, including wrong surface production and hole generation. In the paper, we re-assign zero to vertices in the surface and one to vertices on the surface, and then improve the marching cubes algorithm by redefining the configurations for the fifteen cases of configurations proposed in marching cubes method. To evaluate the performance of the improved marching cubes method, we reconstructed the surface for MRI volume data using the improved method along with the marching cubes method. The experimental results show that the improved method can remove the disadvantages mentioned above and obtain a satisfying reconstructed surface
Computer modeling and simulation are important for the researches and applications of the fiber optic gyroscope (FOG). In the paper, the dynamic model and stochastic model of digital closed-loop FOG are developed. Wit...
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Computer modeling and simulation are important for the researches and applications of the fiber optic gyroscope (FOG). In the paper, the dynamic model and stochastic model of digital closed-loop FOG are developed. With a number of reasonable approximations, the nonlinear dynamic model is simplified into a linear discrete dynamic model. The digital control algorithm in the closed-loop control is analyzed, and the dynamic simulation is conducted. In the stochastic modeling, different stochastic processes are built to simulate the various types of random gyro noise. A novel method is investigated to simulate 1/f noise with the orthogonal wavelet transform. The stochastic simulations are conducted and the effectiveness of the stochastic model is validated with Allan variance analysis
In the framework of linear matrix inequalities (LMI) optimization, an output feedback H infin control scheme for uncertain discrete-time systems with actuator saturation is presented. The key of this work is to intro...
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In the framework of linear matrix inequalities (LMI) optimization, an output feedback H infin control scheme for uncertain discrete-time systems with actuator saturation is presented. The key of this work is to introduce a dissipation constraint combined with minimizing performance level, and then to discuss the closed-loop H infin performance. Moreover, we propose the method for on-line solving the constrained optimization problem at each sampling time, updated with the controller states. This scheme has the capability of automatically relaxing the performance level in order to obey input constraints
Chaotic neural networks have been applied to solve function optimization problems successfully. To improve the optimization capacity of the chaotic neural network, a new chaotic neural network model called wavelet cha...
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In this paper, a distributed robust control scheme is proposed for formation stabilization of noholonomic wheeled mobile robots (WMRs) with parametric uncertainty and actuator saturations. A quasi-LPV model is first e...
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In this paper, a distributed robust control scheme is proposed for formation stabilization of noholonomic wheeled mobile robots (WMRs) with parametric uncertainty and actuator saturations. A quasi-LPV model is first established to describe the error dynamics of each WMR. For a given cost function, we generate distributed optimal control problems for each interacting robot whose error dynamics and constraints are uncoupled. In the framework of LMI optimization, a distributed moving horizon H infin control scheme is consequently formulated as on-line solving each constrained optimal problem synchronously at each sampling time. We also discuss the closed-loop properties inclusive of stability and H infin performance. Simulation is performed to highlight the effectiveness of the proposed distributed control law
This paper addresses the problem of attitude tracking controller design of a rigid spacecraft, whose nonlinear equations of motion is considered directly without linearization. The modified Rodrigues parameters (MRP) ...
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ISBN:
(纸本)0780393953
This paper addresses the problem of attitude tracking controller design of a rigid spacecraft, whose nonlinear equations of motion is considered directly without linearization. The modified Rodrigues parameters (MRP) is used as kinematic variables, which allows principal angle rotations up to 360/spl deg/. By applying nonlinear H/sub /spl infin// controltheory, we design an attitude tracking controller which guarantees a prescribed L/sub 2/ gain performance for the closed-loop system. That is, the L/sub 2/ gain from exogenous disturbance to performance output is less than a scalar. To the best of our knowledge, this approach represents the first solution to the attitude tracking control problem for MRP representation. Numerical simulations are eventually included, and the results show that the derived nonlinear H/sub /spl infin// controller ensures global asymptotical stability and disturbance attenuation capacity of the closed-loop tracking error system.
An adaptive predictive control method is presented for nonlinear discrete system by introducing multi-layer recursive method into the predictive control strategy. In this method, nonlinear system is substituted with a...
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The design of robust tracking observer for a class of perturbed descriptor control systems is investigated in this paper. Based on the parametric solutions to a generalized Sylvester matrix equation, the robust index ...
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ISBN:
(纸本)0780393953
The design of robust tracking observer for a class of perturbed descriptor control systems is investigated in this paper. Based on the parametric solutions to a generalized Sylvester matrix equation, the robust index and the matrices of tracking observer are parameterized and the problem of designing robust tracking observer is changed into a minimization problem. A simple and effective algorithm for the design of robust tracking observer is proposed. An illustrative example and its simulation results show the simplicity and effectiveness of the proposed algorithm.
In order to compensate for the effects of friction in IOC (inter-satellite optical communication) coarse pointing subsystem of PAT (pointing, acquisition, tracking) system, a PD controller is used to obtain a stable t...
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In order to compensate for the effects of friction in IOC (inter-satellite optical communication) coarse pointing subsystem of PAT (pointing, acquisition, tracking) system, a PD controller is used to obtain a stable trajectory first, then wavelet neural network is used to approximate friction function on line to compensate for it. In addition, a robust term is used to eliminate the effects of approximation error of neural network and external disturbances. The system is proved to be stable and the parameters are proved to be bounded under the control scheme of this paper, using Lyapunov function methods. At last, simulation results show the validity of the control scheme
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