线性离散周期系统输出反馈参数化极点配置

采用周期输出反馈的途径, 考虑了线性离散时间周期系统的极点配置问题. 通过将闭环单值性矩阵进行一系列转化, 周期输出反馈律的求解问题可以转化为一类Sylvester矩阵方程的求解问题. 利用Sylvester矩阵方程的最新结果, 可以将输出反馈增益表示为参数化形式, 从而得到了能够实现极点配置的所有输出反馈控制器. 数值算例验证了方法的有效性.     

Output feedback eigenstructure assignment using two Sylvesterequations

The eigenstructure assignment problem with output feedback is studied for systems satisfying the condition p+m> n. The main tool used is the concept of (C, A, B)-invariance and two coupled Sylvester equations, the solution of which leads to the computation of an output stabilizing feedback. A computationally efficient algorithm for the solution of these two coupled equations, which leads to the computation of a desired output feedback, is presented     

A bilinear formulation for the output feedback problem in linearsystems

This note ties together a geometric theory and previous algebraic results for the closed-loop eigenstructure assignment by output feedback in multivariable systems. Necessary and sufficient conditions for the closed-loop stabilization, eigenstructure assignment are presented in terms of a bilinear Sylvester equation, the solutions of which completely characterize the closed-loop eigenstructure problem with output feedback. Some preliminary results for the solution of this bilinear equation are presented     

Output feedback eigenstructure assignment using a new reduced orthogonality condition

This paper presents a new method of output feedback eigenstructure assignment. A new, reduced orthogonality condition is derived which is less restrictive on the design degrees of freedom than others in the literature. From this a novel, general formulation for the gain matrix is admitted which utilizes a two stage design process. In the first stage, a subset of desired eigenvectors is assigned, either left or right. In the second stage, a dual set is assigned which adheres to the necessary and sufficient conditions for output feedback eigenstructure assignment proved earlier in the paper. A numerical example is presented to illustrate the whole procedure.     

Eigenstructure assignment by decentralized output feedback-acomplete parametric approach

The problem of eigenstructure assignment in multivariable linear systems by decentralized output feedback is considered. By using a complete parametric solution of a generalized Sylvester matrix equation, parametric representations of both the left and right closed-loop eigenvectors and generalized eigenvectors as well as the feedback gains with respect to the closed-loop eigenvalues and two series of partially free parameter vectors are established. The obtained result does not require any conditions on the closed-loop eigenvalues, and generalizes some previous results in this area. An example shows the effect of the proposed approach     

二维线性系统特征结构配置的两种新算法

本文提出了二维线性系统特征结构配置的两种新算法,并给出了状态反馈矩阵存在的充分条件。     

Two parametric approaches for eigenstructure assignment in second-order linear systems

This paper considers eigenstructure assignment in second-order linear systems via proportional plus derivative feedback . It is shown that the problem is closely related to a type of so-called second-order Sylvester matrix equations. Through establishing two general parametric solutions to this type of matrix equations, two complete parametric methods for the proposed eigenstructure assignment problem are presented. Both methods give simple complete parametric expressions for the feedback gains and the closed-loop eigenvector 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 right factorization of the system, and allows the closed-loop eigenvalues to be set undetermined and sought via certain optimization procedures. An example shows the effectiveness of the proposed approaches.     

Parametric control to a type of quasi-linear second-order systems via output feedback

This paper considers the design of output feedback control for a type of quasi-linear second-order systems with the time-varying coefficient matrices containing the state variables and a time-varying parameter vector. Based on the solution to a type of second-order generalised Sylvester matrix equations, general complete parameterisation of a quasi-linear output feedback controller is established with respect to the state variables, the time-varying parameter vector, the constant closed-loop system and another two groups of arbitrary parameters, and also for the left and right closed-loop eigenvectors matrices. With the proposed parametric output feedback control, the closed-loop system can be transformed into a constant linear system with desired eigenstructure. Finally, simulation results are provided to illustrate the convenience and effectiveness of application in the general spacecraft rendezvous problem.     

Parametric Jordan Form Assignment Revisited

The Jordan form assignment problem (complete and partial) for linear multivariable control system is formulated and completely solved by the unified Sylvester matrix equation approach. A new explicit parametrization of all state feedbacks assigning an admissible Jordan form through the minimum number of parameters is provided. The main advantage of this parametrization, unlike previous ones, is that it is explicit; thus, it can be used, not only for numeric, but also symbolic computations. This fact is demonstrated on the problem of parametrization of all output feedbacks assigning an admissible Jordan form, where Gröbner basis method is applied. Developed algorithms for Jordan form assignment by state and output feedback are implemented in the freely available Maple package.     

Feedback gain optimization in decentralized eigenvalue assignment

This paper develops a new design procedure for minimizing the norm of a decentralized output feedback matrix which assigns a user specified set of eigenvalues. Two distinct approaches which can be meshed together as a unified design tool are derived. Assuming one has computed a decentralized feedback matrix which assigns a desired spectrum, the first approach describes an iterative algorithm which reduces an algebraic cost function (e.g. the Frobenius norm) of the feedback gains while maintaining the desired spectrum. This algorithm allows for small movements in the eigenvalues. The iteration step is based on the first order variational behaviour of the eigenvalue-eigenvector equations. The second algorithm modifies a continuation method for decentralized eigenvalue assignment to include an optimizing factor. Numerical considerations for the design procedures are discussed. An example showing the improvement possible by the application of the procedure is also given.     

A continuation approach to eigenvalue assignment

This paper describes a continuation approach to eigenvalue assignment. The method is a homotopy technique which embeds the control problem into a parameterized family of control problems. This parameterization describes a continuous deformation of a system with the desired spectrum into the original system. Based on this deformation, a differential equation is constructed whose solution trajectory has an end-point which is a constant output feedback matrix assigning the desired spectrum to the original system. The derivation of this differential equation and conditions which guarantee the existence of a solution are given. Also, two examples of its numerical implementation are detailed.     

切换系统输出反馈镇定的特征结构配置方法

考虑由单输入--单输出线性子系统构成的切换系统, 通过解析方法设计输出反馈控制, 使闭环子系统具有公共二次Lyapunov函数. 基于可解Lie代数条件及广义Sylvester方程的通解, 利用特征结构配置方法建立了反馈控制的存在性准则, 并由此给出了控制器的设计形式. 仿真算例实现了设计过程并验证了方法的有效性.     

A unified method for optimal arbitrary pole placement

We consider the classic problem of pole placement by state feedback. We offer an eigenstructure assignment algorithm to obtain a novel parametric form for the pole-placing feedback matrix that can deliver any set of desired closed-loop eigenvalues, with any desired multiplicities. This parametric formula is then exploited to introduce an unconstrained nonlinear optimisation algorithm to obtain a feedback matrix that delivers the desired pole placement with optimal robustness and minimum gain. Lastly we compare the performance of our method against several others from the recent literature.     

ESA in high‐order linear systems via output feedback

This paper considers eigenstructure assignment in high‐order linear systems via output feedback. Parametric expressions for the left and right closed‐loop eigenvectors associated with the finite closed‐loop eigenvalues and two simple and complete parametric solutions for the feedback gain matrices are obtained on the basis of the parametric solutions of the generalized high‐order Sylvester matrix equations. This approach does not impose any restrictions on the closed‐loop eigenvalues. An illustrative example shows the effect of the proposed approach. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

用输出反馈配置鲁棒极点*

本文讨论了线性定常多变量系统在时域上用输出反馈配置鲁棒极点的问题。用输出反馈配置极点时,有一些自由度,可以利用这些自由度指定特征向量。本文给出一种数值方法,它用于选择一组尽可能正交的特征向量,使闭环系统矩阵A+BKC尽可能接近正规,从而使闭环极点对于矩阵的系数变化是鲁棒的。     

Some necessary and sufficient conditions for eigenstructure assignment

Some necessary and sufficient conditions for closed-loop eigenstructure assignment by output feedback in time-invariant linear multivariable control systems are presented. A simple condition on a square matrix necessary and sufficient for it to be the closed-loop plant matrix of a given system with some output feedback is the basis of the paper. Some known results on entire eigenstructure assignment are deduced from this. The concept of an inner inverse of a matrix is employed to obtain a condition concerning the assignment of an eigenstructure consisting of the eigenvalues and a mixture of left and right eigenvectors.