关联时滞大系统的分散H_∞控制器的设计

研究了具有N×N个任意未知常时滞的线性连续大系统的分散H∞ 状态反馈控制器和H∞ 输出反馈控制器的设计问题 ,分别给出了使系统渐近稳定且具有H∞ 扰动抑制度γ的分散H∞ 状态反馈控制器和分散H∞ 输出反馈控制器存在的充分条件 ,该条件以线性矩阵不等式的形式给出 ,因而具有数值易解性。最后用一个事例来说明分散H∞ 状态反馈控制器和输出反馈控制器的设计。     

具有测量数据丢失的大系统鲁棒H∞控制

研究一类具有测量数据丢失的大系统分散H∞控制器设计问题.针对由个子系统构成的线性离散大系统,假设测量数据丢失满足已知概率的Bernoulli分布,采用线性矩阵不等式方法给出了分散H∞控制器存在的充分条件,所设计的控制器使得闭环系统均方指数稳定,且满足指定的H∞性能指标.通过仿真例子验证了该方法的有效性.     

广义大系统非脆弱分散Ｈ_∞控制器设计

针对控制器增益具有模有界扰动的情况,研究广义大系统非脆弱分散H∞控制问题.基于广义系统的有界实引理和线性矩阵不等式(LMI)方法,分别给出了广义大系统非脆弱分散H∞控制器和非脆弱分散H∞保性能控制器存在的充分条件和设计方法.最后通过仿真算例表明了所提出方法的有效性.     

Linear periodic controller design for decentralized control systems

In the decentralized control of linear time-invariant (LTI) systems, a decentralized fixed mode (DFM) is a system mode which is immoveable using an LTI controller, while a quotient DFM (QDFM) is one which is immoveable using any form of nonlinear time-varying compensation. If a system has no unstable DFMs, there are well-known procedures for designing an LTI stabilizing controller; for systems which have unstable DFMs but no unstable QDFMs, we provide a simple design algorithm which yields a linear periodic sampled-data stabilizing controller.     

H∞ decentralized fuzzy model reference tracking controldesign for nonlinear interconnected systems

In general, due to the interactions among subsystems, it is difficult to design an H_∞ decentralized controller for nonlinear interconnected systems. The model reference tracking control problem of nonlinear interconnected systems is studied via H_∞ decentralized fuzzy control method. First, the nonlinear interconnected system is represented by an equivalent Takagi-Sugeno type fuzzy model. A state feedback decentralized fuzzy control scheme is developed to override the external disturbances such that the H∞ model reference tracking performance is achieved. Furthermore, the stability of the nonlinear interconnected systems is also guaranteed. If states are not all available, a decentralized fuzzy observer is proposed to estimate the states of each subsystem for decentralized control. Consequently, a fuzzy observer-based state feedback decentralized fuzzy controller is proposed to solve the H_∞ tracking control design problem for nonlinear interconnected systems. The problem of H _∞ decentralized fuzzy tracking control design for nonlinear interconnected systems is characterized in terms of solving an eigenvalue problem (EVP). The EVP can be solved very efficiently using convex optimization techniques. Finally, simulation examples are given to illustrate the tracking performance of the proposed methods     

An observer-based decentralized tracker for sampled-data systems: an evolutionary programming approach

Decentralized control is a practical control methodology for large-scale multivariable systems. This paper presents a LQR design methodology to design a state-feedback decentralized high-gain analog controller, which gives the desired decentralized performance of the controlled analog system. Then, a prediction-based decentralized low-gain digital controller is developed from the decentralized high-gain analog controller for the hybrid controlled system. As a result, the complexity and cost of hardware implementation of the controller can be significantly reduced. In order to improve the performance of the decentralized hybrid system, the evolutionary programming (EP) is employed to tune the observer-based decentralized tracker. Some examples are presented to illustrate the developed design methodology.     

Centralized and decentralized supervisory controller design to enforce boundedness,liveness, and reversibility in Petri nets

Supervisory controller design to enforce boundedness, liveness, and reversibility in Petri nets is considered. The Petri nets considered may have non-unity weight arcs and both controllable and uncontrollable transitions. Algorithms for a centralized controller design approach are first developed. The developed algorithms always find a controller whenever it exists. This controller enforces boundedness, liveness, and reversibility; it also avoids deadlock. Furthermore, it is shown that the controller obtained is the least restrictive controller among all controllers which enforce desired properties. A decentralized controller design approach, based on overlapping decompositions, is then introduced. Algorithms to design decentralized controllers based on this approach are also developed. These controllers, when they exist, also guarantees boundedness, liveness, reversibility and deadlock freeness. The decentralized controllers have two main advantages over the centralized ones. First, they have reduced on-line computation and communication requirements. Second, the computational time required to design decentralized controllers is considerably less than that required for centralized controllers.     

Extended H 2 and H norm characterizations and controller parametrizations for discrete-time systems

This paper presents new synthesis procedures for discrete-time linear systems. It is based on a recently developed stability condition which contains as particular cases both the celebrated Lyapunov theorem for precisely known systems and the quadratic stability condition for systems with uncertain parameters. These new synthesis conditions have some nice properties: (a) they can be expressed in terms of LMI (linear matrix inequalities) and (b) the optimization variables associated with the controller parameters are independent of the symmetric matrix that defines a quadratic Lyapunov function used to test stability. This second feature is important for several reasons. First, structural constraints, as those appearing in the decentralized and static output-feedback control design, can be addressed less conservatively. Second, parameter dependent Lyapunov function can be considered with a very positive impact on the design of robust H 2 and H X control problems. Third, the design of controller with mixed objectives (also gain-scheduled controllers) can be addressed without employing a unique Lyapunov matrix to test all objectives (scheduled operation points). The theory is illustrated by several numerical examples.     

Optimal decentralized control of large scale systems

This paper presents a new optimized decentralized controller design method for solving the tracking and disturbance rejection problems for large-scale linear time-invariant systems, using only low-order decentralized controllers. To illustrate the type of results which can be obtained using the new optimized decentralized control design method, the control of a large flexible space structure is studied and compared with the standard centralized LQR-observer controller. The order of the resultant decentralized controller is much smaller than that of the standard centralized LQR-observer controller. The proposed controller also has certain fail-safe properties and, in addition, it can be five orders of magnitude more robust than the standard LQR-observer controller based on their real stability radii. The new decentralized controller design method is applied to a large flexible space structure system with 5 inputs and 5 outputs and of order 24.     

非线性大系统的分散线性化与分散控制

将非线性控制系统的精确线性化方法应用于非线性大系统,提出了非线性大系统 的分散线性化方法,并得到了非线性系统可分散线性化的充要条件.按照这个方法,可将难度 较大的一类非线性大系统分散控制器的设计转化为易于处理的线性大系统分散控制器的设 计.在得到该线性大系统的分散控制器后,可通过分散坐标变换的逆变换将线性大系统的控 制器变换为原非线性大系统的控制器.同时,控制器的分散性保持不变.该方法明显地降低了 该类非线性大系统分散控制器的设计难度.     

基于H∞理论的关联大系统分散鲁棒控制

基于H∞理论提出了关联大系统分散鲁棒控制的一种新的设计方法.得到的控制器不但 使闭环系统渐近稳定,而且能使闭环系统从扰动输入到被控输出的传递矩阵的H∞范数小于 某个给定的扰动变小常数,并对系统参数的不确定性具有鲁棒性.     

具有非线性关联的广义分散系统的镇定问题

利用变结构控制思想研究具有非线性关联的大型广义不确定系统的镇定问题。在一定条件下对系统设计了分散变结构控制器及安全分散变结构控制器，由于切换函数中动态补偿器的引入，使得设计简单，易于工程实现。     

一类不确定关联时滞大系统的分散H∞ 控制器设计—LMI方法

研究了一类具有N×N个任意未知常时滞和具有范数有界时变不确定的线性连续大系统的分散鲁棒H∞ 状态反馈控制器设计问题 ,基于线性矩阵不等式方法得到了一个使该系统存在无记忆H∞ 状态反馈控制器的充分条件 ,最后通过一个数值例子来说明分散H∞ 状态反馈控制器的设计     

基于线性矩阵不等式的分散H2/H∞控制的次优设计

用线性矩阵不等式(LMI)方法研究大系统分散H2/H∞控制问题,提出了存在分散 H2/H∞状态反馈控制器的参数化定理和两种基于LMI的设计方法:直接LMI方法和迭代LMI (ILMI)方法.所获得的控制器具有块对角结构,闭环系统稳定且能优化闭环系统的H2/H∞性 能指标,示例说明了该算法的应用.     

不确定线性内互联大系统的分散鲁棒H∞控制

讨论含有界不确定性的线性内互联大系统,通过分散状态反馈和分散动态输出反馈的鲁棒Ｈ∞控制问题,首先给出一个重要引理,然后基于有界实引理分别导出放动态输出反馈的分散鲁棒Ｈ∞控制问题有解的充分必要条件,该条件及其问题的求解等价地转化成一个线性矩阵不等式和双线性矩阵不等式的求解。     

时滞不确定线性互联大系统分散鲁棒H∞控制

讨论了含多重控制和状态时变时滞的不确定线性互联大系统的分散鲁棒H∞控制问 题,给出分散状态反馈问题有解的充分条件,并将其转化为一个线性矩阵不等式的求解.     

Overlapping control design for multi-channel systems

This paper deals with the decentralized overlapping control of interconnected systems. The notion of a quotient overlapping fixed mode (QOFM) is first introduced and it is shown that a mode of an interconnected linear time-invariant system can be shifted by means of a general decentralized overlapping controller if and only if it is not a QOFM. It is then asserted that any interconnected system with no unstable QOFM can be stabilized by using an appropriate finite-dimensional linear time-varying controller. It is also shown how the existing results aiming at designing a decentralized controller of a certain type such as generalized sampled-data hold function, finite-dimensional linear time-varying, and sampled-data can be utilized to design a decentralized overlapping controller of a desired form, in order to achieve any design specification. The efficacy of the results is elucidated through two numerical examples.     

Decentralized stable factors and a parameterization ofdecentralized controllers

Decentralized stable factors (DSF) are used to extend the stable factorization approach to the design of decentralized controllers. The DSF allow a parameterization of all the stabilizing decentralized controllers in the form of a Youla parameterization. A decentralized controller serves as the central controller, and the Youla parameter has a particular structure and must satisfy an interaction constraint. This parameterization encompasses several other parameterization results on decentralized control systems     

Independent design of robust partially decentralized controllers

An independent design method for robust partially decentralized controllers is developed. In the proposed design method, the partially decentralized control system is first expanded to the nonsquare decentralized structure. Using the Internal Model Control parametrization, the independent design procedure for robust nonsquare decentralized controllers can then be applied directly to the expanded system. Two examples, including a nonlinear stirred mixing tank, are used to illustrate the developed design method and a comparison to a decentralized controller is made.     

一类不确定离散切换模糊组合系统的稳定性控制

以模糊T-S模型对离散切换组合系统的研究模型进行重新构建,分别利用单Lyapunov函数方法设计出分散切换律和控制器,给出了利用矩阵不等式表达的系统在分散切换律和分散控制器作用下的可镇定条件,仿真结果表明了该方法的有效性。