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2006 China International Conference on Electricity Distribution, CICED 2006

作者： Zhang, Zhigang Shen, Yi Department of Control Science and Engineering Harbin Institute of Technology No.92 West Da-Zhi Street Harbin 150001 China School of Information Technology and Photo-Electronics Yantai University No.30 Qing-Quan Road yantai 264005 China

ISBN: (纸本)0863416381

The power system harmonics measurement is a key technique to control and manage the power quality. This paper present a new method based on wavelet and neural networks to overcome much more drawbacks of conventional Fourier transform, such as palisades effects, leakage phenomena and the shortage of local information. The method not only avoids the disadvantages that only use wavelet transform can not obtain the precise value at a particular harmonic frequency, but also reduces the defect of neural networks that determine the number of nodes hardly, optimize the weights very complexity, and take long training time. Simulation results of Matlab have proved that the presented method has a higher accuracy, a smaller computing quantity and a simpler neural network training, and then the method is reasonable valid.

关键词： Wavelet transforms

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A DESIGN OF H∞ STATIC OUTPUT FEEDBACK control FOR CONSTRAINED DISCRETE-TIME SYSTEM USING MOVING HORIZON SCHEME

A DESIGN OF H∞ STATIC OUTPUT FEEDBACK CONTROL FOR CONSTRAIN...

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2006 International Conference on Machine Learning and Cybernetics(IEEE第五届机器学习与控制论坛)

作者： ZHI-YUAN LIU JUAN WANG RUN PEI HONG CHEN Department of Control Science and Engineering Harbin Institute of Technology Harbin 150001 China Department of Control Science and Engineering Jilin University Changchun 130025 China

The constrained H∞ static output feedback control scheme is addressed for discrete-time with control constraints.A sufficient condition is presented for the static output feedback stabilization and H∞ performance for linear *** condition is expressed as linear matrix inequality feasibility problems. By adding dissipation constraint to the mentioned condition, the problem of designing controller is then formulated as on-line constrained optimization ***-loop properties including stability and H∞ performance are discussed in the framework of dissipation theory.

关键词： H∞ performance Static output feedback Linear matrix inequality optimization Input constraints

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Single access antenna pointing control system design of TDRS

Single access antenna pointing control system design of TDRS

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Systems and control in Aerospace and Astronautics, 2006. ISSCAA 2006. 1st International Symposium on

作者： Jinpeng Yuan Di Yang Xiaosong Sun Department of Astronautic Engineering Harbin Institute of Technology Harbin China Beijing Institute of Control Engineering Beijing China

ISBN: (纸本)0780393953

Tracking and data relay satellite system (TDRSS) is one of the hot spots in the development of the aerospace engineering recently. It is a challenging task to design the SA pointing control system with high pointing accuracy to ensure the communication between the tracking and data relay satellite (TDRS) and the user satellites. The SA pointing control system is designed in this paper in detail. Firstly the dynamic model of the TDRS is established using the Lagrange equation. Secondly the control scheme of the TDRS satellite is selected for the main body and the single access antennae. The tracking laws are derived and the antenna's azimuth and elevation angles can be derived by the tracking laws when the TDRS is tracking the user satellites. Thirdly the antenna pointing control concepts are described, and the on-board autonomous control method is designed. The on-board autonomous control scheme is composed of acquisition and autotrack modes. On one hand the acquisition process of the SA antenna is designed. On the other hand, the antenna step logic of the autotrack mode is properly selected. The SA antenna is driven by two-phase permanent magnetic stepper motor, and the mathematical model of the stepper motor is established. Finally, the mathematic simulation of the antenna pointing control system designed in this paper is conducted in the case of taking the user satellite and the ground station as tracking objects according to tracking laws derived before, and the SA antenna pointing performance of the TDRS is demonstrated by the analysis of the simulation results.

关键词： aerospace control control system synthesis pointing systems satellite antennas satellite tracking stepping motors Lagrange equation SA antenna TDRS satellite TDRSS acquisition modes antenna pointing control system design antenna step logic autotrack mode

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H/sub /spl infin// synthesis for satellite formation keeping: an LMI approach

H/sub /spl infin// synthesis for satellite formation keeping...

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Systems and control in Aerospace and Astronautics, 2006. ISSCAA 2006. 1st International Symposium on

作者： Baolin Wu Xibin Cao Fuchun Liu Research Center of Satellite Technology Harbin Institute of Technology Harbin China Department of Control Science and Engineering Harbin Institute of Technology Harbin China

ISBN: (纸本)0780393953

Numerous controllers have been proposed based on linear Hill's equations for satellite formation control. To date, most of these controllers assumed that the system model is well defined, and the disturbances are small. Previous studies have failed to consider the problem of disturbance rejection. In this paper, H/sub /spl infin// controllers are designed for disturbance attenuation based on linear Hill's equations. The goal is to design a state-feedback control law which minimizes the H/sub /spl infin// norm of transfer function from disturbance to the regulated outputs, which guarantee stable for the closed-loop system. The problem is reduced to a convex optimization involving linear matrix inequalities (LMIs). The proposed robust controllers are evaluated in simulation. The simulation results demonstrate that the proposed controllers are capable of controlling the satellite formation system more precisely than LQR under various perturbations.

关键词： H/sup /spl infin// control aerospace control artificial satellites closed loop systems convex programming linear matrix inequalities robust control state feedback transfer functions H/sub /spl infin// controllers H/sub /spl infin// synthesis closed-loop

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Relative Attitude control in Satellite Formation Flying with Information Delay

Relative Attitude Control in Satellite Formation Flying with...

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World Congress on Intelligent control and Automation (WCICA)

作者： Huayi Li Yingchun Zhang Wenyi Qiang Baohua Li Research Center of Satellite Harbin Institute of Technology Harbin China Department of Control Science and Engineering Harbin Institute of Technology Harbin China

In leader-follower formation flying, using the leader's rate of rotation, the follower calculates the target attitude and rate of rotation, which are necessary to relative attitude control. In the process of information collecting, computing and transmitting, time delay exists that causes information delay. To deal with it, rate and attitude estimators are presented which provide target rate and attitude real time. Then a PID control law for small satellite with reaction wheels is developed based on them. Simulation results show the approach is valid

关键词： Satellites Delay effects Three-term control Delay estimation Attitude control Wheels Computational modeling NASA Global Positioning System Intelligent control

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Chaos Algorithm of Multilayer Feedforward Neural Network

Chaos Algorithm of Multilayer Feedforward Neural Network

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Chinese control Conference (CCC)

作者： Jia-hai Zhang Yao-qun Xu College of Electrical and Automatic Engineering Sanjiang University Nanjing China Center for Control Theory and Guidance Technology Harbin Institute of Technology Harbin China

By the use of the properties of ergodicity, a chaos algorithm for multilayer feedforward neural network is proposed with combining logistic mapping and BP algorithm. This algorithm can make BP algorithm to skip the lo... 详细信息

关键词： Multi-layer neural network Chaos Neural networks Feedforward neural networks Educational institutions control theory Electronic mail Logistics Convergence TV

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Application of one-degree-of-freedom QFT tracking controller to hydraulic simulator design

Application of one-degree-of-freedom QFT tracking controller...

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Systems and control in Aerospace and Astronautics, 2006. ISSCAA 2006. 1st International Symposium on

作者： Jinying Yu Keding Zhao Jian Cao Liquid Transmission and Control Laboratory Department of Mechanical Engineering Harbin Institute of Technology Harbin China

ISBN: (纸本)0780393953

Phase tracking problem is not especially considered in classical quantitative feedback theory (QFT). A modified one-degree-of-freedom QFT technique which is suitable for both magnitude and phase tracking performance index is proposed to synthesize three-axis hydraulic simulator controller. The proposed method transform uncertain plant tracking performance index into sensitivity constraint and nominal plant tracking error constraint. The former constraint form into QFT sensitivity bounds and the latter one can be founded on Nichols chart directly. Because of omitting pre-filter of classical two-degree-of-freedom QFT control structure, ramp tracking performance index is also enhanced greatly. The modified QFT technique's efficacy is validated by simulation results.

关键词： controllers feedback hydraulic control equipment Nichols chart degree-of-freedom hydraulic simulator controller magnitude tracking nominal plant tracking error constraint phase tracking quantitative feedback theory ramp tracking performance index sensiti

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Noisy image segmentation by modified snake model

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Journal of Physics: Conference Series 2006年第1期48卷 369-372页

作者： Lu, R. Shen, Y. Department of Control Science and Engineering Harbin Institute of Technology Harbin China

A novel segmentation scheme for noisy image is proposed. According to the analysis of wavelet denoising method and multiscale geometric analysis techniques, an improved wavelet denoising algorithm combined with multiscale geometric analysis is presented in this paper first. Due to the isotropic nature of wavelet transform, 2D image details are not well represented in wavelet transform, which results in over smoothing. In this new denoising method, a noisy image is processed by the wavelet denoising method first, and then edges' information which has been wrongly discarded, is picked up from the residue image by multiscale geometric analysis. The final denoising image is a combination of the wavelet denoising result and the edges' information. Furthermore, incorporating prior knowledge on the contours' shape and shape similarity metric based on Fourier descriptors of snakes, a parameter-varying snake model is introduced. It addresses the problem of varying parameters during snake method. Extensive experimental results illustrate the excellent performance. © 2006 IOP Publishing Ltd.

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A Delta-operator Approach to Robust Stabilization for Uncertain Time-delay Systems with Jumping Parameter

A Delta-operator Approach to Robust Stabilization for Uncert...

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World Congress on Intelligent control and Automation (WCICA)

作者： Kai-yu Wu Yan-ming Fu Shuang Li School of Mechanical & Power Engineering Harbin University of Science and Technology Heilongjiang China Center for Control Theory and Guidance Technology Harbin Institute of Technology Heilongjiang China

This paper deals with the robust stabilization for a class of linear Delta-operator formulated uncertain systems with state delays and jumping parameters. The transition of the jumping parameters in systems is governed by a finite-state Markov process. The class of systems is a hybrid class of systems with two components in the vector state. The first component refers to the mode and the second one to the state. The mode is described by a continuous Markov process with finite state space. The state in each mode is denoted by a stochastic differential equation. Based on stability theory in stochastic differential equations, a sufficient condition on the existence of robust stabilizing control law is derived. Based on this condition, a robust memoryless stabilizing control law is designed in terms of a set of linear matrix inequalities. A numerical example demonstrates the effect of the proposed design approach

关键词： Robustness Markov processes Stochastic processes Differential equations Robust stability Robust control Uncertain systems Delay systems Vectors State-space methods

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Optimal Piecewise State Feedback control for Nonlinear Dynamical Systems

Optimal Piecewise State Feedback Control for Nonlinear Dynam...

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World Congress on Intelligent control and Automation (WCICA)

作者： Rui Li Kok Lay Teo Guangren Duan Center for Control Theory and Guidance Technology Harbin Institute of Technology Harbin China Department of Mathematics & Statistics Curtin University of Technology Perth WA Australia

In this paper, we consider a class of optimal piecewise state feedback control problems. For this optimal control problem, the time horizon is divided into N subintervals with the end points of each subinterval being referred to as switching times. The control is given by a piecewise state feedback form, where different feedback gain matrices are allowed for different subintervals. Both the switching instants and the feedback gain matrices on the corresponding subintervals are decision variables to be determined such that a given cost functional is minimized. Our approach is to use a time scaling transform to convert this optimal piecewise state feedback control problem into an equivalent optimal parameter selection problem, where the varying time points are being mapped into fixed time points. Then the gradient formulae of the cost functional are derived. On this basis, the equivalent transformed optimal parameter selection problem can be solved as a nonlinear optimization problem. An illustrative example is solved using the proposed method

关键词： State feedback Optimal control Nonlinear control systems control systems Nonlinear dynamical systems Cost function Matrix converters Automobiles Vehicle driving Differential equations

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