2005年 第31卷 第5期
2005, 31(5): 655-661.
摘要:
Using the framework of predictive control algorithms and the analysis results of unconstrained predictive control systems, the desired pole placement is achieved by the coefficient mapping between the characteristic polynomials of the closed-loop system and the open-loop plant. The designed control law can not only ensure the dynamical performance of the closed-loop system, but also provide plentiful degrees of freedom to satisfy input-output constraints. Based on the theory of invariant set, this paper derives some sufficient conditions for the satisfaction of constraints with these degrees of freedom and presents an approach to design corresponding constrained controller.The constrained controller with performance guarantee can be designed off-line. Furthermore, it has convenient on-line computation and satisfies all constraints. A simulation example is presented to illustrate the proposed approach.
Using the framework of predictive control algorithms and the analysis results of unconstrained predictive control systems, the desired pole placement is achieved by the coefficient mapping between the characteristic polynomials of the closed-loop system and the open-loop plant. The designed control law can not only ensure the dynamical performance of the closed-loop system, but also provide plentiful degrees of freedom to satisfy input-output constraints. Based on the theory of invariant set, this paper derives some sufficient conditions for the satisfaction of constraints with these degrees of freedom and presents an approach to design corresponding constrained controller.The constrained controller with performance guarantee can be designed off-line. Furthermore, it has convenient on-line computation and satisfies all constraints. A simulation example is presented to illustrate the proposed approach.
2005, 31(5): 662-667.
摘要:
Some results on linear system theory are reported. Based on these results, necessary and sufficient conditions for the controllability and observability of both continuous-time and its corresponding discrete-time multivariable linear time-invariant systems are presented.
Some results on linear system theory are reported. Based on these results, necessary and sufficient conditions for the controllability and observability of both continuous-time and its corresponding discrete-time multivariable linear time-invariant systems are presented.
2005, 31(5): 668-674.
摘要:
This paper analyzes noise sensitivity of bidirectional association memory (BAM) and shows that the anti-noise capability of BAM relates not only to the minimum absolute value of net inputs(MAV), as some researchers found, but also to the variance of weights associated with synapse connections. In fact, it is determined by the quotient of these two factors. On this base, a novel learning algorithm—small variance leaning for BAM(SVBAM) is proposed, which is to decrease the variance of the weights of synapse matrix. Simulation experiments show that the algorithm can decrease the variance of weights efficiently, therefore, noise immunity of BAM is improved. At the same time, perfect recall of all training pattern pairs still can be guaranteed by the algorithm.
This paper analyzes noise sensitivity of bidirectional association memory (BAM) and shows that the anti-noise capability of BAM relates not only to the minimum absolute value of net inputs(MAV), as some researchers found, but also to the variance of weights associated with synapse connections. In fact, it is determined by the quotient of these two factors. On this base, a novel learning algorithm—small variance leaning for BAM(SVBAM) is proposed, which is to decrease the variance of the weights of synapse matrix. Simulation experiments show that the algorithm can decrease the variance of weights efficiently, therefore, noise immunity of BAM is improved. At the same time, perfect recall of all training pattern pairs still can be guaranteed by the algorithm.
2005, 31(5): 675-682.
摘要:
A novel decentralized PID controller design procedure based on backstepping principles is presented to operate multiple-input multiple-output (MIMO) dynamic processes. The first key feature of the design procedure is that a whole MIMO control system is decomposed into multiple control loops, therefore the sub-controllers can be efficiently flexibly designed in parallel prototype. The second key feature is that the decentralized controller has equivalency to those designed by backstepping approach. As a complementary support to the design procedure, the sufficient condition of the whole closed-loop system stability is analyzed via the small gain theorem and it can be proven that the process tracking performance is improved. The simulation results of the Shell benchmark control problem are provided to verify the effectiveness and practicality of the proposed decentralized PID control.
A novel decentralized PID controller design procedure based on backstepping principles is presented to operate multiple-input multiple-output (MIMO) dynamic processes. The first key feature of the design procedure is that a whole MIMO control system is decomposed into multiple control loops, therefore the sub-controllers can be efficiently flexibly designed in parallel prototype. The second key feature is that the decentralized controller has equivalency to those designed by backstepping approach. As a complementary support to the design procedure, the sufficient condition of the whole closed-loop system stability is analyzed via the small gain theorem and it can be proven that the process tracking performance is improved. The simulation results of the Shell benchmark control problem are provided to verify the effectiveness and practicality of the proposed decentralized PID control.
2005, 31(5): 683-692.
摘要:
Robustness is one of the most important requirements of digital watermarking for many applications. Spread-spectrum based methods are not effective enough to ensure their robustness. By modeling digital watermarking as digital communications, several researchers proposed using error correcting coding (ECC) to improve robustness. However, an important fact that has long been neglected is that due to the imperceptibility requirement, the redundancy introduced by ECC will lead to a decrease of the magnitude of watermark signal. Therefore, a problem arises naturally: Could the usage of ECC effectively improve the robustness of watermarking? This paper addresses this problem from the perspectives of both theoretical analysis and experimental investigation. Our investigation shows that ECC cannot effectively improve the robustness of watermarking against a great majority of various attacks except for cropping and jitter attacks. Hence, ECC should not be considered as a universal measure that can be employed to enhance robustness of watermarking.
Robustness is one of the most important requirements of digital watermarking for many applications. Spread-spectrum based methods are not effective enough to ensure their robustness. By modeling digital watermarking as digital communications, several researchers proposed using error correcting coding (ECC) to improve robustness. However, an important fact that has long been neglected is that due to the imperceptibility requirement, the redundancy introduced by ECC will lead to a decrease of the magnitude of watermark signal. Therefore, a problem arises naturally: Could the usage of ECC effectively improve the robustness of watermarking? This paper addresses this problem from the perspectives of both theoretical analysis and experimental investigation. Our investigation shows that ECC cannot effectively improve the robustness of watermarking against a great majority of various attacks except for cropping and jitter attacks. Hence, ECC should not be considered as a universal measure that can be employed to enhance robustness of watermarking.
2005, 31(5): 693-698.
摘要:
This paper presents a novel depth estimation method based on feature points. Two points are selected arbitrarily from an object and their distance in the space is assumed to be known.The proposed technique can estimate simultaneously their depths according to two images taken before and after a camera moves and the motion parameters of the camera may be unknown. In addition, this paper analyzes the ways to enhance the precision of the estimated depths and presents a feature point image coordinates search algorithm to increase the robustness of the proposed method.The search algorithm can find automatically more accurate image coordinates of the feature points based on their detected image coordinates. Experimental results demonstrate the efficiency of the presented method.
This paper presents a novel depth estimation method based on feature points. Two points are selected arbitrarily from an object and their distance in the space is assumed to be known.The proposed technique can estimate simultaneously their depths according to two images taken before and after a camera moves and the motion parameters of the camera may be unknown. In addition, this paper analyzes the ways to enhance the precision of the estimated depths and presents a feature point image coordinates search algorithm to increase the robustness of the proposed method.The search algorithm can find automatically more accurate image coordinates of the feature points based on their detected image coordinates. Experimental results demonstrate the efficiency of the presented method.
2005, 31(5): 699-704.
摘要:
The discrete wavelet transform has become an attractive tool for fusing multisensor images. This paper investigates the discrete wavelet frame transform. A major advantage of this method over discrete wavelet transform is aliasing free and translation invariant. The discrete wavelet frame (DWF) transform is used to decompose the registered images into multiscale representation with the low frequency and the high frequency bands. The low frequency band is normalized and fused by using the expectation maximization (EM) algorithm. The informative importance measure is applied to the high frequency band. The final fused image is obtained by taking the inverse transform on the composite coefficient representations. Experiments show that the proposed method is more effective than conventional image fusion methods.
The discrete wavelet transform has become an attractive tool for fusing multisensor images. This paper investigates the discrete wavelet frame transform. A major advantage of this method over discrete wavelet transform is aliasing free and translation invariant. The discrete wavelet frame (DWF) transform is used to decompose the registered images into multiscale representation with the low frequency and the high frequency bands. The low frequency band is normalized and fused by using the expectation maximization (EM) algorithm. The informative importance measure is applied to the high frequency band. The final fused image is obtained by taking the inverse transform on the composite coefficient representations. Experiments show that the proposed method is more effective than conventional image fusion methods.
2005, 31(5): 705-712.
摘要:
An adaptive image watermarking algorithm based on HMM in wavelet domain is proposed. The algorithm is abstracted as follows: 1) the vector HMM model is employed to describe the statistical characteristic of image wavelet coefficients and the resulting HMM based detector achieves significant improvements in performance compared to the conventional correlation detector; 2) adaptive watermark embedding based on HVS analysis; 3) a novel embedding strategy which is optimized for the HMM tree structure is adopted; 4) the strategy of dynamical threshold is applied in watermark detection. High robust results are achieved against Stirmark attacks, such as JPEG compression, adding noise, median cut and filter.
An adaptive image watermarking algorithm based on HMM in wavelet domain is proposed. The algorithm is abstracted as follows: 1) the vector HMM model is employed to describe the statistical characteristic of image wavelet coefficients and the resulting HMM based detector achieves significant improvements in performance compared to the conventional correlation detector; 2) adaptive watermark embedding based on HVS analysis; 3) a novel embedding strategy which is optimized for the HMM tree structure is adopted; 4) the strategy of dynamical threshold is applied in watermark detection. High robust results are achieved against Stirmark attacks, such as JPEG compression, adding noise, median cut and filter.
2005, 31(5): 713-719.
摘要:
A novel subpixel corner detection method based on spatial moment is developed in this paper. Firstly, the spatial-moment-generating function, gradient magnitude and variation of gradient-direction corner are used as the decision rule of corner detection by analyzing the mathematical formula of corner-model spatial moment. Then Non-max suppression technique is utilized to detect the vertex of feature corner. Finally, in order to improve its localization performance, subpixel corner detection is implemented by the bilinear interpolation and Newton iteration method. Experiments illustrate that the spatial moment corner detector has better robustness and localization performance than Kitchen detector and Harris detector.
A novel subpixel corner detection method based on spatial moment is developed in this paper. Firstly, the spatial-moment-generating function, gradient magnitude and variation of gradient-direction corner are used as the decision rule of corner detection by analyzing the mathematical formula of corner-model spatial moment. Then Non-max suppression technique is utilized to detect the vertex of feature corner. Finally, in order to improve its localization performance, subpixel corner detection is implemented by the bilinear interpolation and Newton iteration method. Experiments illustrate that the spatial moment corner detector has better robustness and localization performance than Kitchen detector and Harris detector.
2005, 31(5): 720-726.
摘要:
This paper develops delay-independent fuzzy hyperbolic guaranteed cost control for non-linear continuous-time systems with parameter uncertainties. Fuzzy hyperbolic model (FHM) can be used to establish the model for certain unknown complex system. The main advantage of using FHM over Takagi-Sugeno (T-S ) fuzzy model is that no premise structure identification is needed and no completeness design of premise variables space is needed. In addition, an FHM is not only a kind of valid global description but also a kind of nonlinear model in nature. A nonlinear quadratic cost function is developed as a performance measurement of the closed-loop fuzzy system based on FHM. Based on delay-independent Lyapunov functional approach, some sufficient conditions for the existence of such a fuzzy hyperbolic guaranteed cost controller via state feedback are provided. These conditions are given in terms of the feasibility of linear matrix inequalities (LMIs). A simulation example is provided to illustrate the design procedure of the proposed method.
This paper develops delay-independent fuzzy hyperbolic guaranteed cost control for non-linear continuous-time systems with parameter uncertainties. Fuzzy hyperbolic model (FHM) can be used to establish the model for certain unknown complex system. The main advantage of using FHM over Takagi-Sugeno (T-S ) fuzzy model is that no premise structure identification is needed and no completeness design of premise variables space is needed. In addition, an FHM is not only a kind of valid global description but also a kind of nonlinear model in nature. A nonlinear quadratic cost function is developed as a performance measurement of the closed-loop fuzzy system based on FHM. Based on delay-independent Lyapunov functional approach, some sufficient conditions for the existence of such a fuzzy hyperbolic guaranteed cost controller via state feedback are provided. These conditions are given in terms of the feasibility of linear matrix inequalities (LMIs). A simulation example is provided to illustrate the design procedure of the proposed method.
2005, 31(5): 727-736.
摘要:
This paper presents a generalized bi-level programming model of combined dynamic traffic assignment and traffic signal control, and especially analyzes a procedure for determining the equilibrium queuing delays on saturated links for dynamic network signal control satisfying the FIFO (first-in-first-out) rule. The chaotic optimal algorithm proposed in this paper can not only present the optimal signal settings, but also calculate, at each interval, the link inflow rates and outflow rates for the dynamic user optimal problem, and provide real-time information for the travelers. Finally, a numerical example is given to illustrate the application of the proposed model and solution algorithm, and comparison shows that this model has better system performance.
This paper presents a generalized bi-level programming model of combined dynamic traffic assignment and traffic signal control, and especially analyzes a procedure for determining the equilibrium queuing delays on saturated links for dynamic network signal control satisfying the FIFO (first-in-first-out) rule. The chaotic optimal algorithm proposed in this paper can not only present the optimal signal settings, but also calculate, at each interval, the link inflow rates and outflow rates for the dynamic user optimal problem, and provide real-time information for the travelers. Finally, a numerical example is given to illustrate the application of the proposed model and solution algorithm, and comparison shows that this model has better system performance.
2005, 31(5): 737-742.
摘要:
In a sensor network, reasonable distribution of sensor nodes will do much good to the improvement of sensorial ability. In a sensor network constructed by randomly scattering, a better sensing coverage can be achieved by topology adjustment utilizing mobility of some sensor nodes. To solve this problem, we define an extending-tree in the sensor network using Voronoi diagrams and Delaunay network. On this base, a new optimization algorithm of sensor node distribution based on genetic algorithm is designed, which provides a sound effective means to improve the sensorial ability of network. Simulation output shows that this algorithm can achieve an optimizing node distribution in the object area, by which sensorial ability of the whole sensor network can be improved at a relatively low cost.
In a sensor network, reasonable distribution of sensor nodes will do much good to the improvement of sensorial ability. In a sensor network constructed by randomly scattering, a better sensing coverage can be achieved by topology adjustment utilizing mobility of some sensor nodes. To solve this problem, we define an extending-tree in the sensor network using Voronoi diagrams and Delaunay network. On this base, a new optimization algorithm of sensor node distribution based on genetic algorithm is designed, which provides a sound effective means to improve the sensorial ability of network. Simulation output shows that this algorithm can achieve an optimizing node distribution in the object area, by which sensorial ability of the whole sensor network can be improved at a relatively low cost.
2005, 31(5): 743-749.
摘要:
This paper discusses the phenomena of sliding mode in dynamic behavior of planar switched systems. We propose an approach to estimate the domain in which the sliding motion may occur. The relationship between the chattering angle and the switching time is given and utilized to check the existence of sliding mode with chattering. Finally, the application of the proposed results is illustrated by an example.
This paper discusses the phenomena of sliding mode in dynamic behavior of planar switched systems. We propose an approach to estimate the domain in which the sliding motion may occur. The relationship between the chattering angle and the switching time is given and utilized to check the existence of sliding mode with chattering. Finally, the application of the proposed results is illustrated by an example.
2005, 31(5): 750-758.
摘要:
提出一种新的神经网络模型---时滞标准神经网络模型(DSNNM),它由线性动力学系统和有界静态时滞非线性算子连接而成.利用不同的Lyapunov泛函和S方法推导出DSNNM全局渐近稳定性和全局指数稳定性的充分条件,这些条件可表示为线性不等式(LMI)形式.大多数时滞(或非时滞)动态神经网络(DANN)稳定性分析或神经网络控制系统都可以转化为DSNNM,以便用统一的方法进行稳定性分析或镇定控制.从DSNNM应用于时滞联想记忆(BAM)神经网络的稳定性分析以及PH中和过程神经控制器的综合实例,可以看出,得到的稳定性判据扩展并改进了以往文献中的稳定性定理,而且可将稳定性分析推广到非线性控制系统的综合.
提出一种新的神经网络模型---时滞标准神经网络模型(DSNNM),它由线性动力学系统和有界静态时滞非线性算子连接而成.利用不同的Lyapunov泛函和S方法推导出DSNNM全局渐近稳定性和全局指数稳定性的充分条件,这些条件可表示为线性不等式(LMI)形式.大多数时滞(或非时滞)动态神经网络(DANN)稳定性分析或神经网络控制系统都可以转化为DSNNM,以便用统一的方法进行稳定性分析或镇定控制.从DSNNM应用于时滞联想记忆(BAM)神经网络的稳定性分析以及PH中和过程神经控制器的综合实例,可以看出,得到的稳定性判据扩展并改进了以往文献中的稳定性定理,而且可将稳定性分析推广到非线性控制系统的综合.
2005, 31(5): 759-764.
摘要:
研究了开放环境下多比特量子计算系统的相干控制建模问题.基于开放量子系统的数学模型,选取适当的矩阵基将描述多比特量子计算机的复矩阵动态控制模型转化为实向量空间上的控制模型,并给出计算相应的结构系数的方法.这些工作提供了进一步研究控制律设计的基础.
研究了开放环境下多比特量子计算系统的相干控制建模问题.基于开放量子系统的数学模型,选取适当的矩阵基将描述多比特量子计算机的复矩阵动态控制模型转化为实向量空间上的控制模型,并给出计算相应的结构系数的方法.这些工作提供了进一步研究控制律设计的基础.
2005, 31(5): 765-771.
摘要:
Production scheduling is critical to manufacturing system. Dispatching rules are usually applied dynamically to schedule the job in a dynamic job-shop. Existing scheduling approaches sel- dom address machine selection in the scheduling process. Composite rules, considering both machine selection and job selection, are proposed in this paper. The dynamic system is trained to enhance its learning and adaptive capability by a reinforcement learning (RL) algorithm. We define the conception of pressure to describe the system feature. Designing a reward function should be guided by the scheduling goal to accurately record the learning progress. Competitive results with the RL-based approach show that it can be used as real-time scheduling technology.
Production scheduling is critical to manufacturing system. Dispatching rules are usually applied dynamically to schedule the job in a dynamic job-shop. Existing scheduling approaches sel- dom address machine selection in the scheduling process. Composite rules, considering both machine selection and job selection, are proposed in this paper. The dynamic system is trained to enhance its learning and adaptive capability by a reinforcement learning (RL) algorithm. We define the conception of pressure to describe the system feature. Designing a reward function should be guided by the scheduling goal to accurately record the learning progress. Competitive results with the RL-based approach show that it can be used as real-time scheduling technology.
2005, 31(5): 772-778.
摘要:
In this article, we study the locally distributed feedback stabilization problem of a nonuniform Euler-Bernoulli beam. Firstly, using the semi-group theory, we establish the well-posedness of the associated closed loop system. Then by proving the uniqueness of the solution to a related ordinary differential equation, we derive the asymptotic stability of the closed loop system. Finally, by means of the piecewise multiplier method, we prove that, by either one distributed force feedback or a distributed moment feedback control, the closed loop system can be exponentially stabilized.
In this article, we study the locally distributed feedback stabilization problem of a nonuniform Euler-Bernoulli beam. Firstly, using the semi-group theory, we establish the well-posedness of the associated closed loop system. Then by proving the uniqueness of the solution to a related ordinary differential equation, we derive the asymptotic stability of the closed loop system. Finally, by means of the piecewise multiplier method, we prove that, by either one distributed force feedback or a distributed moment feedback control, the closed loop system can be exponentially stabilized.
2005, 31(5): 779-781.
摘要:
In this paper, we study the robust control for uncertain Markov jump linear singularly perturbed systems (MJLSPS), whose transition probability matrix is unknown. An improved heuristic algorithm is proposed to solve the nonlinear matrix inequalities. The results of this paper can apply not only to standard, but also to nonstandard MJLSPS. Moreover, the proposed approach is independent of the perturbation parameter and therefore avoids the ill-conditioned numerical problems.
In this paper, we study the robust control for uncertain Markov jump linear singularly perturbed systems (MJLSPS), whose transition probability matrix is unknown. An improved heuristic algorithm is proposed to solve the nonlinear matrix inequalities. The results of this paper can apply not only to standard, but also to nonstandard MJLSPS. Moreover, the proposed approach is independent of the perturbation parameter and therefore avoids the ill-conditioned numerical problems.
2005, 31(5): 782-787.
摘要:
The principal component analysis (PCA), or the eigenfaces method, is a de facto standard in human face recognition. Numerous algorithms tried to generalize PCA in different aspects. More recently, a technique called two-dimensional PCA (2DPCA) was proposed to cut the computational cost of the standard PCA. Unlike PCA that treats images as vectors, 2DPCA views an image as a matrix. With a properly defined criterion, 2DPCA results in an eigenvalue problem which has a much lower dimensionality than that of PCA. In this paper, we show that 2DPCA is equivalent to a special case of an existing feature extraction method, i.e., the block-based PCA. Using the FERET database, extensive experimental results demonstrate that block-based PCA outperforms PCA on datasets that consist of relatively simple images for recognition, while PCA is more robust than 2DPCA in harder situations.
The principal component analysis (PCA), or the eigenfaces method, is a de facto standard in human face recognition. Numerous algorithms tried to generalize PCA in different aspects. More recently, a technique called two-dimensional PCA (2DPCA) was proposed to cut the computational cost of the standard PCA. Unlike PCA that treats images as vectors, 2DPCA views an image as a matrix. With a properly defined criterion, 2DPCA results in an eigenvalue problem which has a much lower dimensionality than that of PCA. In this paper, we show that 2DPCA is equivalent to a special case of an existing feature extraction method, i.e., the block-based PCA. Using the FERET database, extensive experimental results demonstrate that block-based PCA outperforms PCA on datasets that consist of relatively simple images for recognition, while PCA is more robust than 2DPCA in harder situations.
2005, 31(5): 788-792.
摘要:
A new sliding mode controller design method is proposed for a class of system with mismatched uncertainties such that the dynamic function restricted on the sliding surface is completely insensitive to the uncertainties. A sufficient and necessary condition which the system possessing this sliding mode controller should satisfy is explicitly presented. The issue of chattering free is also explored. It is concluded that this class of mismatched term does not bring any chattering problem. Finally, a numerical example illustrates the developed method.
A new sliding mode controller design method is proposed for a class of system with mismatched uncertainties such that the dynamic function restricted on the sliding surface is completely insensitive to the uncertainties. A sufficient and necessary condition which the system possessing this sliding mode controller should satisfy is explicitly presented. The issue of chattering free is also explored. It is concluded that this class of mismatched term does not bring any chattering problem. Finally, a numerical example illustrates the developed method.
2005, 31(5): 793-798.
摘要:
For a class of MIMO plants, using the idea of the high-frequency gain matrix Kp = L2D2S2 factorization, the problem of design and analysis for MRAC is further investigated under the single assumption of known signs of the leading principal minors of Kp. By proving the Lp and L2 relationship properties between the input and the output and the multivariable swapping lemmas, the relation between all the signals in the closed-loop system and the normalized signal is obtained and the stability and tracking performance of the adaptive system is analyzed rigorously, the proof procedure being more compact.
For a class of MIMO plants, using the idea of the high-frequency gain matrix Kp = L2D2S2 factorization, the problem of design and analysis for MRAC is further investigated under the single assumption of known signs of the leading principal minors of Kp. By proving the Lp and L2 relationship properties between the input and the output and the multivariable swapping lemmas, the relation between all the signals in the closed-loop system and the normalized signal is obtained and the stability and tracking performance of the adaptive system is analyzed rigorously, the proof procedure being more compact.
2005, 31(5): 799-803.
摘要:
An adaptive output feedback neural network tracking controller is designed for a class of unknown output feedback nonlinear time-delay systems by using backstepping technique. Neural networks are used to approximate unknown time-delay functions. Delay-dependent filters are introduced for state estimation. The domination method is used to deal with the smooth time-delay basis functions. The adaptive bounding technique is employed to estimate the upper bound of the neural network reconstruction error. Based on Lyapunov-Krasoviskii functional, the semi-global uniform ultimate boundedness (SGUUB) of all the signals in the closed-loop system is proved. The arbitrary output tracking accuracy is achieved by tuning the design parameters and the neural node number. The feasibility is investigated by an illustrative simulation example.
An adaptive output feedback neural network tracking controller is designed for a class of unknown output feedback nonlinear time-delay systems by using backstepping technique. Neural networks are used to approximate unknown time-delay functions. Delay-dependent filters are introduced for state estimation. The domination method is used to deal with the smooth time-delay basis functions. The adaptive bounding technique is employed to estimate the upper bound of the neural network reconstruction error. Based on Lyapunov-Krasoviskii functional, the semi-global uniform ultimate boundedness (SGUUB) of all the signals in the closed-loop system is proved. The arbitrary output tracking accuracy is achieved by tuning the design parameters and the neural node number. The feasibility is investigated by an illustrative simulation example.
2005, 31(5): 804-807.
摘要:
Based on design of an observer, the issue of dynamic output feedback control is studied for uncertain discrete systems with delays. A comparison theorem is given for nonlinear uncertain discrete systems with multiple time delays. Based on the comparison theorem with some inequalities, some delay-independent sufficient conditions for the robust stabilization of the systems are presented by means of output feedback.
Based on design of an observer, the issue of dynamic output feedback control is studied for uncertain discrete systems with delays. A comparison theorem is given for nonlinear uncertain discrete systems with multiple time delays. Based on the comparison theorem with some inequalities, some delay-independent sufficient conditions for the robust stabilization of the systems are presented by means of output feedback.
2005, 31(5): 808-814.
摘要:
The problem of optimal guaranteed cost control for discrete-time singular large-scale systems with a quadratic cost function is considered in this paper. The system under discussion is subject to norm bounded time-invariant parameter uncertainty in all the matrices of model. The problem we address is to design a state feedback controller such that the closed-loop system not only is robustly stable but also guarantees an adequate level of performance for all admissible uncertainties. A sufficient condition for the existence of guaranteed cost controllers is presented in terms of linear matrix inequalities (LMIs), and a desired state feedback controller is obtained via convex optimization. An illustrative example is given to demonstrate the effectiveness of the proposed approach.
The problem of optimal guaranteed cost control for discrete-time singular large-scale systems with a quadratic cost function is considered in this paper. The system under discussion is subject to norm bounded time-invariant parameter uncertainty in all the matrices of model. The problem we address is to design a state feedback controller such that the closed-loop system not only is robustly stable but also guarantees an adequate level of performance for all admissible uncertainties. A sufficient condition for the existence of guaranteed cost controllers is presented in terms of linear matrix inequalities (LMIs), and a desired state feedback controller is obtained via convex optimization. An illustrative example is given to demonstrate the effectiveness of the proposed approach.
